JP5365400B2 - Gradation mask and gradation mask manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gradation mask with which members with different heights and shapes can be efficiently manufactured with high flexibility. <P>SOLUTION: The gradation mask includes: a transparent substrate; a shading film directly formed on the transparent substrate and made of a shading film forming material; a first translucent film formed on the transparent substrate and made of a first translucent film forming material; and a second translucent film formed on the transparent substrate and made of a second translucent film forming material. The gradation mask includes: a transparent region made of the transparent substrate; a shading region including the transparent substrate and the shading film at least; a first translucent region made of the transparent substrate and the first translucent film; and a second translucent region made of the transparent substrate and the second translucent film. The second translucent film forming material has different resistance to etching solution from that of the first translucent film forming material. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a gradation mask that can form members having different heights and shapes with high degree of freedom and efficiency.

  Regarding a pattern formation method for reducing the number of lithography processes of a display device such as a liquid crystal display device or an organic electroluminescence display device, a photomask (slit mask) having a minute slit below the resolution limit of exposure light, and exposure light A photomask having a gradation (gradation mask) is disclosed (Patent Document 1).

In the slit mask, a general light shielding film such as a chromium film that substantially shields exposure light is used, and a fine slit below the resolution limit of the exposure machine is disposed in the light shielding film (see, for example, Patent Document 2). Since the mask slit is not larger than the resolution limit, the mask slit itself does not form an image on the photosensitive resin layer, and the exposure light corresponding to the size is applied to the area including the surrounding non-opening area. To Penetrate. For this reason, the slit mask functions as if a translucent film exists in the area where the slit is formed and the area including the periphery of the area.
However, since this slit needs to be below the resolution limit, it is natural that the slit needs to be finished to a size smaller than the mask main body pattern, resulting in a large burden on mask manufacturing. It was. Furthermore, in order to make a wide area semi-transparent, it is necessary to arrange many slits, so that the pattern data capacity increases, and there arises a problem that the load on the pattern formation process and the pattern defect inspection process also increases. -There was a problem that the inspection time was increased and the mask manufacturing cost was increased.

On the other hand, the gradation mask uses a light-shielding film that substantially shields exposure light and a translucent film that transmits exposure light at a desired transmittance, and a light-transmissive area that does not transmit light. And a translucent region in which the amount of transmitted light is adjusted (see, for example, Patent Document 3).
As a method of manufacturing such a gradation mask, a method of sequentially etching a mask blank in which the transparent substrate, the light shielding film forming layer, and the semitransparent film forming layer are stacked can be exemplified. For this reason, the gradation mask has an advantage that it is not necessary to form a fine slit like the above-described slit mask and can be easily formed.

On the other hand, for example, in a color filter, there is a demand to form not only members having different heights but also members having different heights and shapes with high flexibility and efficiency. Specifically, as a translucent region member that is a member formed at a position corresponding to the translucent region, it is desired to collectively form a member whose height is accurately controlled, a member having a different top shape, etc. There was a request.
However, the above-described conventional gradation mask has a problem that it is difficult to satisfy such a requirement.

JP 2000-66240 A JP 2002-196474 A JP 2002-189280 A

  The present invention has been made in view of the above problems, and a main object of the present invention is to provide a gradation mask that can efficiently form members having different heights and shapes with a high degree of freedom.

  As a result of repeated studies to solve the above problems, the present inventor has found that the shape of the obtained member differs depending on the constituent material of the translucent film, the tendency of the height change and the ease of control differ. The present invention has been completed.

  That is, the present invention provides a transparent substrate, a light shielding film formed directly on the transparent substrate and made of a light shielding film forming material, and a first semitransparent film made of the first semitransparent film forming material formed on the transparent substrate. A film, and a second semi-transparent film formed on the transparent substrate and made of a second semi-transparent film forming material, and including at least the transmission region made of the transparent substrate, the transparent substrate, and the light-shielding film A gradation mask comprising: a light shielding region; a first translucent region composed of the transparent substrate and the first translucent film; and a second translucent region composed of the transparent substrate and the second translucent film. The gradation mask is characterized in that the second translucent film forming material is different from the first translucent film forming material in resistance to the etching solution.

According to the present invention, since the second translucent film forming material is different from the first translucent film forming material in resistance to the etching solution, two kinds of the first translucent film and the second translucent film are used. The semitransparent film can be easily formed independently.
For this reason, according to the height, shape, etc. of the member formed using the gradation mask of the present invention, the spectral spectrum, transmittance, etc. of the first semitransparent film and the second semitransparent film are easily different. be able to. For this reason, members having different heights and shapes can be collectively formed with a high degree of freedom.

  In the present invention, one of the first translucent film forming material and the second translucent film forming material is a chromium-based material, and the first translucent film forming material and the second translucent film forming material are used. The other of these is preferably a titanium-based material. One of the first translucent film forming material and the second translucent film forming material is a chromium-based material, and the other of the first translucent film forming material and the second translucent film forming material is a titanium-based material. By being a material, the first semi-transparent film forming material and the second semi-transparent film forming material can be greatly different in resistance to the etching solution. For this reason, it is because the said 1st semi-transparent film | membrane and a 2nd semi-transparent film | membrane can be formed more easily.

  In the present invention, the light shielding film forming material is the same material as one of the first semitransparent film forming material and the second semitransparent film forming material, and the light shielding film comprises the first semitransparent film and It is preferable that it is covered with at least one of the second translucent films. Since the light shielding film forming material is the same kind of material as any one of the first semitransparent film forming material and the second semitransparent film forming material, the light shielding film forming material can be formed using the same etching solution. This is because costs can be reduced. In addition, since the light shielding film is covered with at least one of the first semi-transparent film and the second semi-transparent film, a light shielding film with good pattern accuracy can be obtained.

  In the present invention, it is preferable that the spectrum of the first translucent film is different from the spectrum of the second translucent film. This is because the spectral spectrum of the first translucent film and the spectral spectrum of the second translucent film can be different so that members having different heights and shapes can be formed with a high degree of freedom.

  The present invention provides a light shielding film by etching the light shielding film forming layer of a laminate having a transparent substrate and a light shielding film forming layer formed on the transparent substrate and made of a light shielding film forming material into a pattern. Forming a first semi-transparent film forming layer made of a first semi-transparent film forming material on the transparent substrate so as to cover the light-shielding film, and then forming the first semi-transparent film. A first semi-transparent film forming step for forming a first semi-transparent film directly formed on the transparent substrate by etching the film forming layer in a pattern, and the light-shielding film and the first film on the transparent substrate After forming the second semi-transparent film forming layer made of the second semi-transparent film forming material having different resistance to the etching solution from the first semi-transparent film forming material so as to cover the first semi-transparent film, The translucent film forming layer is the first translucent film type. A second translucent film that forms a second translucent film directly formed on the transparent substrate by etching in a pattern with an etchant for forming a second translucent film, which is an etchant having a material resistance And a step of forming the gradation mask.

According to the present invention, a transmission region composed of the transparent substrate, a light shielding region including at least the transparent substrate and the light shielding film, a first semitransparent region composed of the transparent substrate and the first semitransparent film, and the transparent A gradation mask including a substrate and a second semi-transparent region made of the second semi-transparent film can be formed.
Further, the light shielding film forming step is performed before the first semitransparent film forming step and the second semitransparent film forming step, that is, the light shielding film forming layer is formed by only one etching. Thus, the light shielding film can be formed without being affected by the positional deviation due to the alignment accuracy. Further, since the light shielding film is usually used for forming the main pattern of the gradation mask, it can be a mask with excellent pattern accuracy.
Further, the first translucent film forming step and the second translucent film forming step are provided, and the first translucent film and the second translucent film are independently formed. Therefore, the first translucent film is formed. The spectral spectrum, transmittance, and the like of the film and the second translucent film can be easily made different. For this reason, it is possible to obtain a mask that can collectively form members having different heights and shapes with a high degree of freedom.

  The present invention has an effect that members having different heights and shapes can be efficiently formed with a high degree of freedom.

It is a schematic sectional drawing which shows an example of the gradation mask of this invention. It is a schematic sectional drawing which shows an example of the color filter which has a member from which height etc. differ. It is a schematic sectional drawing which shows the other example of the color filter which has a member from which height etc. differ. It is process drawing which shows an example which forms each member of a color filter using the gradation mask of this invention. It is process drawing which shows the other example which forms each member of a color filter using the gradation mask of this invention. It is explanatory drawing explaining the spectral spectrum of the semi-transparent film | membrane in this invention. It is process drawing which shows an example of the manufacturing method of the gradation mask of this invention. It is process drawing which shows the other example of the manufacturing method of the gradation mask of this invention.

The present invention relates to a gradation mask and a manufacturing method thereof.
Hereinafter, the gradation mask of the present invention and the method of manufacturing the gradation mask will be described in detail.

A. Tone Mask First, the tone mask of the present invention will be described. The gradation mask of the present invention is a transparent substrate, a light shielding film formed directly on the transparent substrate, made of a light shielding film forming material, and a first semi-transparent film forming material formed on the transparent substrate. A translucent film, and a second translucent film formed on the transparent substrate and made of a second translucent film-forming material, and having a transmission region made of the transparent substrate, the transparent substrate, and the light-shielding film. A gradation mask comprising at least a light-shielding region, a first semi-transparent region composed of the transparent substrate and the first semi-transparent film, and a second semi-transparent region composed of the transparent substrate and the second semi-transparent film. The second semitransparent film forming material is different from the first semitransparent film forming material in that the resistance to the etching solution is different.

Such a gradation mask of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view showing an example of the gradation mask of the present invention. As illustrated in FIG. 1, a gradation mask 10 of the present invention is formed on a transparent substrate 1, a light shielding film 2 formed directly on the transparent substrate 1 and made of a light shielding film forming material, and the transparent substrate 1. A first translucent film 3 made of a first translucent film-forming material, and a second translucent film 4 made of the second translucent film-forming material and formed on the transparent substrate 1, A transparent region 11 comprising a transparent substrate 1, a light shielding region 12 including at least the transparent substrate 1 and the light shielding film 2, a first semitransparent region 13 comprising the transparent substrate 1 and the first semitransparent film 3, and the above A transparent substrate 1 and a second translucent region 14 made of the second translucent film 4 are provided.
In this example, the entire surface of the light shielding film 2 is covered with the first translucent film 3. A part of the first translucent film 3 is covered with the second translucent film 4.

Components used in liquid crystal display devices, organic electroluminescence display devices, and the like are required to have a plurality of members having different heights and shapes due to recent increases in size and accuracy. Further, each member is required to be formed with high accuracy.
For example, as a color filter used in a liquid crystal display device, as illustrated in FIG. 2, a substrate, a light-shielding portion formed on the substrate and having an opening, and a colored layer formed in the opening. In addition to the spacers (the first spacer 41 and the second spacer 42) formed on the color filter forming substrate 30 having high accuracy, the collar has an alignment control protrusion 44 which is a member having a shape different from that of the spacer. As illustrated in FIG. 3, a color filter 40 having spacers (first spacer 41, second spacer 42, and third spacer 43) adjusted to be slightly different in height is required. Yes. Thus, formation of a member whose height and the like are adjusted with high accuracy is required.
However, it has been difficult with conventional gradation masks to form such high-precision members with high accuracy and the required height and shape.

On the other hand, according to the present invention, since the second translucent film forming material is different from the first translucent film forming material in resistance to the etching solution, the first translucent film and the second translucent film are formed. These two types of semitransparent films can be easily formed independently.
For this reason, for example, even the first and second semitransparent films having different spectral spectra can be easily formed, and when exposed through such a gradation mask of the present invention, Two or more types of exposure light having different spectral shapes can be obtained.
When the photosensitive resin is exposed with exposure light having such different spectral shapes, the cured state of the photosensitive resin can be changed according to the spectral shapes.
Here, the height of the semi-transparent film was accurately controlled at a position corresponding to the semi-transparent region by having a spectral spectrum corresponding to the shape required for the member, the height accuracy, and the like. Two or more types of members, members having different top shapes, and the like can be collectively formed.

Specifically, as illustrated in FIG. 4, when the photosensitive resin layer 34 on the color filter forming substrate 30 is exposed using the gradation mask 10 illustrated in FIG. 1 (FIG. 4A), As shown in FIG. 4B, the first spacer 41 having a rectangular cross section at a position corresponding to the transmission region 11 and the first spacer 41 at a position corresponding to the first translucent region 13 are provided. The second spacer 42 having a lower cross section and a rectangular cross section, and a semicircle having a smooth top at a position lower than the first spacer 41 at a position corresponding to the second translucent region 14. The color filters 40 having the first alignment control protrusions 44 having a shape can be collectively formed.
In addition, about the code | symbol in FIG.4 (a)-(b), since it shows the member same as the thing of FIG. 1, description here is abbreviate | omitted.

In addition, when the exposure is performed using the gradation mask 10 as shown in FIG. 5A, as illustrated in FIG. 5B, the cross section is rectangular at a position corresponding to the transmission region 11. 1 spacer 41, a first alignment control protrusion 44 having a semicircular shape whose height is lower than that of the first spacer 41 and whose top is smooth, at a position corresponding to the first semi-transparent region 13, and the second A color filter 40 having an overcoat layer 46 having a lower surface than the first alignment control protrusion 44 and a flat surface can be formed at a position corresponding to the translucent region 14.
In addition, about the code | symbol in Fig.5 (a)-(b), since it shows the member same as the thing of FIG. 4, description here is abbreviate | omitted.

  In addition, for example, the first translucent film and the second translucent film are each formed of a translucent film having a spectral spectrum capable of forming a high-height member with high accuracy and a low-height member. By forming a semitransparent film with a spectral spectrum that can be formed with high accuracy, it is possible to form a high-height member and a low-height member in a batch with high accuracy, compared to the case where the thickness of the semitransparent film is simply different. It is possible to do.

  Thus, it is possible to easily adjust the spectrum of the first semi-transparent film and the second semi-transparent film according to the required height, shape, etc. of the member, thereby corresponding to the semi-transparent region. It is possible to form two or more types of members whose heights are accurately controlled at the positions to be performed, members having different top shapes, and the like. For this reason, members having different heights and shapes can be formed efficiently with a high degree of freedom and accuracy.

The gradation mask of the present invention has at least a transparent substrate, a light shielding film, a first semitransparent film, and a second semitransparent film.
Hereafter, each structure of the gradation mask of this invention is demonstrated in detail.

1. First translucent film and second translucent film The first translucent film and the second translucent film used in the present invention are formed on the transparent substrate and have a desired transmittance. .
Further, the second semi-transparent film forming material and the first semi-transparent film forming material are different in resistance to the etching solution.

(1) Translucent film-forming material The first translucent film-forming material and the second translucent film-forming material used in the present invention have different resistances to etching solutions.
Here, the material having different resistance to the etching solution refers to a material in which one material is etched with a predetermined etching solution but the other material is not etched with respect to the predetermined etching solution. . Therefore, the first translucent film forming material may be any material that allows the second translucent film forming material to be etched by an etchant having resistance. As the second translucent film forming material, Any material may be used as long as the first translucent film forming material is etched by a resistant etching solution.

The first semi-transparent film forming material and the second semi-transparent film forming material are different depending on the required spectroscopic spectrum and the like. Specifically, chromium, titanium, molybdenum silicide, tantalum, aluminum, Metals such as silicon and nickel, chromium, titanium, molybdenum silicide, tantalum, aluminum, silicon, nitrides and carbides of metals such as nickel, indium tin oxide (ITO), compounds containing Ti and W, or Examples thereof include compounds containing Ti and Mo.
In the present invention, in particular, one of the first translucent film forming material and the second translucent film forming material is a chromium-based material such as chromium, chromium oxide, chromium nitride, chromium oxynitride, and the first semitransparent film forming material. The other of the transparent film forming material and the second translucent film forming material is a titanium-based material such as titanium, titanium oxide, titanium nitride, titanium oxynitride, a compound containing Ti and W, or a compound containing Ti and Mo. preferable. One of the first translucent film forming material and the second translucent film forming material is a chromium-based material and the other is a titanium-based material, whereby the first translucent film forming material and the second translucent film forming material are formed. The resistance of the material to the etchant can vary greatly. For this reason, it is because the said 1st semi-transparent film | membrane and a 2nd semi-transparent film | membrane can be formed more easily.

(2) Spectral spectrum As the spectral spectrum of the first and second translucent films used in the present invention, a member having a desired shape and height is accurately obtained by exposure using the gradation mask of the present invention. Any material that can be well formed is acceptable.
Here, the spectral spectrum refers to the wavelength dependence of the transmittance. When the light passes through a semitransparent film having a different spectral spectrum, the transmitted exposure light has a spectrum corresponding to the transmitted translucent film. The shapes (wavelength range, peak wavelength, peak intensity ratio, peak half width, etc.) are different.
On the other hand, when the light passes through a semi-transparent film having the same spectral spectrum but different transmittance, the transmitted exposure light has different transmission amounts but the same spectral shape.
In the present invention, it is preferable that the spectrum of the first translucent film is different from the spectrum of the second translucent film. This is because members having different heights and shapes can be collectively formed with a high degree of freedom by having different spectral spectra.

  As such a semitransparent film having a different spectral spectrum, specifically, as shown in FIG. 6, a flat translucent film having a flat wavelength dependency of transmittance within a wavelength range of 300 nm to 450 nm, the wavelength is List positively inclined semi-transparent film with higher transmittance as it becomes longer, short wavelength cut semi-transparent film with extremely low transmittance in the short wavelength region, or negatively inclined semi-transparent film with lower transmittance as the wavelength becomes longer Can do.

In the present invention, in particular, one of the first translucent film and the second translucent film is selected from the flat translucent film, the positively inclined semitransparent film, and the short wavelength cut translucent film. In particular, the first translucent film and the second translucent film are two kinds selected from a flat translucent film, a positively inclined translucent film, and a short wavelength cut translucent film. preferable. When a negative photosensitive resin is exposed through the semi-transparent film to form each member of a color filter, the semi-transparent film is a flat semi-transparent film, so that an overcoat layer having a low height is formed. Etc. can be formed with high accuracy. In addition, since the semi-transparent film is a positively inclined semi-transparent film, a member such as a spacer whose height is required to be accurately controlled can be formed. Furthermore, when the translucent film is a short wavelength cut translucent film, a member such as an alignment control protrusion having a smooth semicircular top can be formed.
As described above, the first translucent film and the second translucent film are selected from a flat translucent film, a positively inclined semitransparent film, and a short wavelength cut translucent film. This is because the tone mask can be formed in a batch with high degree of freedom and with high accuracy in members having different heights and shapes.

Further, since the end of the emission spectrum of a high-pressure mercury lamp generally used in an exposure apparatus is approximately 300 nm, the wavelength of I-line is 365 nm, the wavelength of H-line is 405 nm, and the wavelength of G-line is 436 nm. When the spectral spectra in the range of 300 nm to 450 nm including each wavelength are different, the cured state of the photosensitive resin according to the emission spectrum shape of the exposure light transmitted through the semitransparent film can be effectively changed.
Hereinafter, each of the spectral spectrum type translucent films will be described in detail.

(A) Flat translucent film In this invention, the flat translucent film | membrane whose spectral spectrum is a flat type translucent film | membrane has a flat wavelength dependence of the transmittance | permeability in the range of wavelength 300nm-450nm.

When the photosensitive resin layer made of a negative photosensitive resin is exposed due to the spectral spectrum being a flat type, a member formed at a position corresponding to the flat translucent region made of the flat translucent film and the transparent substrate. The ratio between the height and the height of the member formed at a position corresponding to the transmission region is approximately the ratio between the transmittance of the flat translucent region and the transmittance of the transmission region. For this reason, it is possible to easily form a member whose height is accurately controlled.
In addition, since the material exhibiting the above-described characteristics usually does not change the phase of the transmitted exposure light, even when a flat translucent film having a large film thickness and a low transmittance is used, A member can be accurately formed at a desired position. For this reason, when a negative photosensitive resin is exposed, a low-profile member can be formed with high accuracy.

  As the flat translucent film in the present invention, it is sufficient if the wavelength dependency of the transmittance in the wavelength range of 300 nm to 450 nm is flat, but the transmittance distribution in the wavelength range of 300 nm to 450 nm is 0.07 or less. In particular, the transmittance distribution is preferably 0.05 or less. This is because a member whose height is accurately controlled can be formed.

The transmittance distribution is the difference between the maximum transmittance (T _max ) and the minimum transmittance (T _min ) in the range of 300 nm to 450 nm, and the average transmittance (T _av ) in the range of 300 nm to 450 nm is 2 It is the value divided by the multiplied value. (Transmittance distribution = (T _max −T _min ) / (2T _av ))
The maximum transmittance and the minimum transmittance are the maximum and minimum values of the transmittance in the range of 300 nm to 450 nm, and the average transmittance is the transmittance in the range of 300 nm to 450 nm. The average value.
As a method for measuring the transmittance, a method for measuring the transmittance of the translucent film using the transmittance of the transparent substrate used in the gradation mask of the present invention as a reference (100%) can be employed. As the apparatus, an ultraviolet / visible spectrophotometer (for example, Hitachi U-4000) or an apparatus having a photodiode array as a detector (for example, Otsuka Electronics MCPD2000) can be used.

In addition, the transmittance distribution within the wavelength range of 250 nm to 600 nm of the flat translucent film in the present invention is preferably 0.2 or less, and more preferably 0.1 or less.
In general, in the manufacturing process of a display device such as a liquid crystal display device, the exposure wavelength range is often set within the range of 250 nm to 600 nm as the exposure condition for pattern formation, and thus the transmittance distribution within the range of 250 nm to 600 nm is obtained. This is because, within the above range, a wide wavelength range can be used effectively, which is advantageous for pattern formation, and a member whose height is controlled with higher accuracy can be formed.

The transmittance of the flat translucent film in the present invention at a wavelength of 300 nm varies depending on the use of the gradation mask of the present invention, but is preferably in the range of 10% to 70%, and in particular, 10% It is preferably in the range of -30%, particularly preferably in the range of 10% -20%. As described above, for example, when a high-pressure mercury lamp is used in the exposure apparatus, since the end of the emission spectrum is approximately 300 nm, if the transmittance at a wavelength of 300 nm is in the above range, the resist curing reaction has a short wavelength region. This is because it is possible to more reliably use the light.
Further, as described above, the flat translucent film can accurately form a member at a desired position even when the transmittance is low. Therefore, when the average transmittance is within the above range, the effect of using the flat translucent film can be more effectively exhibited.

  The average transmittance of the flat translucent film in the present invention within the wavelength range of 250 nm to 600 nm varies depending on the use of the gradation mask of the present invention, but is preferably in the range of 10% to 60%. . When the transmittance is within the above range, the difference in height between the member formed by the flat semi-transparent region consisting only of the flat semi-transparent film and the transparent substrate and the member formed by the transmission region consisting of the transparent substrate. This is because it can be made sufficiently large.

As a material constituting the flat translucent film used in the present invention, any material satisfying the above-described spectral spectrum may be used, but one of the first translucent film forming material and the second translucent film forming material is the titanium. When the other material is the above-mentioned chromium-based material, chromium or chromium nitride is preferable. This is because chromium and chromium nitride make it possible to form a flat translucent film having a flat transmittance distribution within a wavelength range of 350 nm to 450 nm.
Further, since the flat translucent film is made of such a material, the phase change of the transmitted exposure light can be small. For this reason, even if it is a case where the flat translucent film | membrane with a low transmittance | permeability is used, a member can be accurately formed in a desired position. For this reason, when a negative photosensitive resin is exposed, a low-profile member can be formed with high accuracy.
Furthermore, when the translucent film-forming material is the chromium-based material and the titanium-based material, the first translucent film and the second translucent film can be easily formed by using the above-described materials. Because.

  In the present invention, the chromium used as the constituent material of the flat translucent film may contain a small amount of oxygen, nitrogen, etc., but the chromium content in the film is 80% by mass or more. Particularly preferred is 95% by mass or more. Moreover, when using the said chromium nitride, it is preferable that nitrogen is contained in the said chromium nitride within the range of 5 mass%-20 mass%. This is because a flat translucent film having a flat transmittance distribution can be formed.

As a member formed using the flat translucent film in the present invention, when the gradation mask of the present invention is used, the height and shape are different, as long as it is composed of members formed in a lump, Various members can be mentioned.
Specifically, when each member constituting the color filter is formed using the gradation mask, the member includes a colored layer containing a pigment having a desired color and a light shielding property such as a carbon fine particle and a metal oxide. A light shielding part containing particles can be mentioned. Also, a spacer which is disposed between the color filter and the thin film transistor (TFT) substrate and is a member for setting the thickness of the liquid crystal layer to a desired thickness, an effect of giving a pretilt angle to the liquid crystal molecules in the vicinity, and electric lines of force Is a member that makes it possible to control the alignment direction of the liquid crystal molecules of the liquid crystal layer in a plurality of directions by protecting the colored layer and the surface of the colored layer. And a protective layer (overcoat layer) which is usually transparent.

In the present invention, an overcoat layer is particularly preferable. As described above, the flat translucent film has a small phase change of the transmitted exposure light. Therefore, even when the film thickness is increased, the flat translucent film does not easily cause a phase difference in the transmitted exposure light. is there. For this reason, it can suppress that a member is formed in the location which was not assumed at the time of design, or a member with an uneven surface is formed.
For this reason, it is usually formed of a negative photosensitive resin and is suitable for forming an overcoat layer that is low in height and requires high flatness.
The members of the color filter as described above can be the same as those generally used for the color filter, and the description thereof is omitted here.

(B) Positively inclined semitransparent film In the present invention, a positively inclined semitransparent film whose spectral spectrum is a positively inclined semitransparent film has a higher transmittance as the wavelength becomes longer in the wavelength range of 300 nm to 450 nm. Is.

Short wavelength light has the property of curing the photosensitive resin layer from the surface. For this reason, when the transmittance of light having a short wavelength is too high, the surface of the photosensitive resin layer is cured first, and patterns having different heights may be formed in the translucent region and the transmissive region. It becomes difficult.
On the other hand, when the spectroscopic spectrum is of the positive tilt type, the transmittance increases as the wavelength increases, so that only the surface of the photosensitive resin layer can be exposed without first curing. For this reason, it is possible to form a member whose height is accurately controlled.
In addition, light in the short wavelength region (about 350 nm to 450 nm) as well as light in the short wavelength region (about 300 nm to 350 nm) can be transmitted with a predetermined transmittance, so that the energy of the light in the short wavelength region is high and cured. The advantage of high speed and the light in the long wavelength range are less likely to scatter compared to the light in the short wavelength range, and can reach the deep part of the photosensitive resin. It is possible to have an advantage that the adhesion of the resin is good.

  As the positively inclined semitransparent film in the present invention, any transmittance may be used as long as the wavelength increases within the wavelength range of 300 nm to 450 nm, but the transmittance at the wavelength of 365 nm is the transmittance at the wavelength of 300 nm. It is preferable that the difference between the transmittance at a wavelength of 365 nm and the transmittance at a wavelength of 300 nm is in the range of 6.5% to 12.5%. For example, when a high-pressure mercury lamp is used in the exposure apparatus, the end of the emission line spectrum is approximately 300 nm and the wavelength of the I-line is 365 nm. Light not only in the wavelength range (about 350 nm to 450 nm) but also in the short wavelength range (about 300 nm to 350 nm) is transmitted through the translucent film with a predetermined transmittance, which is advantageous for pattern formation for the reasons described above. On the other hand, if the difference in transmittance at each wavelength is less than the above range, it becomes difficult to form a pattern having a different height, and if the difference in transmittance at each wavelength exceeds the above range, it is compared with the long wavelength range. This is because the light transmittance in the short wavelength region is remarkably lowered, so that exposure may take time.

  Further, the positively inclined semitransparent film in the present invention has a transmittance at a wavelength of 405 nm larger than a transmittance at a wavelength of 300 nm, and the difference between the transmittance at a wavelength of 405 nm and the transmittance at a wavelength of 300 nm is 10.5% to It is preferable to be in the range of 21.0%. For example, when a high-pressure mercury lamp is used in the exposure apparatus, the wavelength of H-ray is 405 nm. Therefore, if the difference in transmittance at each wavelength is within the above range, not only the long wavelength region but also light in the short wavelength region can be obtained. This is because it passes through the positively inclined semitransparent film with a predetermined transmittance, which is advantageous for pattern formation.

  Furthermore, the positively inclined semitransparent film in the present invention has a transmittance at a wavelength of 436 nm larger than a transmittance at a wavelength of 300 nm, and the difference between the transmittance at a wavelength of 436 nm and the transmittance at a wavelength of 300 nm is 13.5% to It is preferable to be within the range of 27.0%. For example, when a high-pressure mercury lamp is used in the exposure apparatus, the wavelength of G-line is 436 nm. In this case as well, if the difference in transmittance at each wavelength is in the above range, not only the long wavelength region but also Light in a short wavelength region is also transmitted through the translucent film with a predetermined transmittance, which is advantageous for pattern formation.

The transmittance of the positively inclined semitransparent film in the present invention at a wavelength of 300 nm varies depending on the use of the gradation mask of the present invention, but is preferably in the range of 10% to 50%, and in particular, 10 % To 40% is preferable, and 15% to 35% is particularly preferable. As described above, for example, when a high-pressure mercury lamp is used in the exposure apparatus, since the end of the emission spectrum is approximately 300 nm, if the transmittance at a wavelength of 300 nm is in the above range, the resist curing reaction has a short wavelength. This is because the light in the region can be used more reliably.
In addition, when the average transmittance is less than the above range, in the pattern formation using the gradation mask of the present invention, it may be difficult to produce a difference in transmittance between the positively inclined semitransparent region and the light shielding region. Moreover, the material which comprises the said normal inclination semi-transparent film | membrane has the property to change the phase of the light generally transmitted. For this reason, when the average transmittance is less than the above range, the influence due to the phase change is increased, and it becomes difficult to form the member with high accuracy.
For this reason, when the average transmittance is within the above range, the member can be formed with high accuracy.

  The average transmittance of the positively inclined semitransparent film in the present invention within the wavelength range of 250 nm to 600 nm varies depending on the application of the gradation mask of the present invention, but may be in the range of 10% to 60%. preferable. When the transmittance is within the above range, the height of the member formed by the positively inclined semitransparent region consisting only of the positively inclined semitransparent film and the transparent substrate, and the member formed by the transparent region consisting of the transparent substrate This is because the difference can be made sufficiently large.

The material constituting the positively inclined semitransparent film in the present invention may be any material as long as it satisfies the above-described spectral spectrum, but one of the first semitransparent film forming material and the second semitransparent film forming material is the titanium-based material. When the other material is the chromium-based material, chromium oxide and chromium oxynitride are preferable, and chromium oxynitride is particularly preferable. This is because the positively inclined semitransparent film is made of the above-described material, so that it can have the above-described spectral spectrum.
Moreover, when the semi-transparent film forming material is the chromium-based material and the titanium-based material, the first semi-transparent film and the second semi-transparent film can be easily formed by using the above-described materials. Because.

The chromium oxide and chromium oxynitride may contain oxygen, nitrogen, etc., but the chromium content is preferably less than 80%, and more preferably in the range of 30% to 60%. In particular, it is preferable to be within the range of 35% to 45%. It is because it can be set as the semi-transparent film | membrane which satisfies the suitable transmittance | permeability characteristic mentioned above.
When the material is chromium oxynitride (Cr _x O _y N _z ), the element ratio of Cr, O, and N is within Cr: 60%, O: within a range of 30% to 70%, N: 40 %, Preferably Cr: 35% to 45%, O: 40% to 60%, N: 2% to 20%.

As a member formed using the positively inclined semitransparent film in the present invention, any member may be used as long as it is composed of members formed in a lump with different heights and shapes when the gradation mask of the present invention is used. Various members can be mentioned.
Specifically, when each member constituting the color filter is formed using the gradation mask, examples of the member include a colored layer, a light shielding portion, a spacer, an alignment control protrusion, an overcoat layer, and the like. it can.
In the present invention, a spacer is particularly preferable. As described above, the positively inclined translucent film can form a member whose height is accurately controlled. For this reason, it is because it is suitable for formation of the spacer requested | required that height is controlled accurately.

(C) Short-wavelength cut translucent film In the present invention, the short-wavelength cut translucent film, which is a short-wavelength cut-type semitransparent film having a spectral spectrum, is within the wavelength range of 300 nm to 450 nm. Transmission is blocked and the transmittance in the short wavelength region is extremely low.

Short wavelength light has the property of curing the photosensitive resin layer from the surface. For this reason, when the transmittance of light having a short wavelength is too high, the surface of the photosensitive resin layer is cured first, and patterns having different heights may be formed in the translucent region and the transmissive region. It becomes difficult.
On the other hand, the short-wavelength cut translucent film blocks the transmission of exposure light in the short-wavelength region, so that the exposure light after passing through the short-wavelength cut translucent film is the surface of the photosensitive resin layer. It is possible to reduce the content of short wavelengths that are easily absorbed. For this reason, hardening of the surface of the photosensitive resin layer can be made gentle. Therefore, a semicircular member having a smooth top can be formed.

  The short wavelength cut translucent film in the present invention may be any film as long as the exposure light transmission in the short wavelength region is blocked within the wavelength range of 300 nm to 450 nm, but the transmittance at a wavelength of 300 nm is 5% or less. It is preferable that the transmittance at a wavelength of 380 nm is 45% or more. This is because a member having a semicircular shape with a smooth top can be formed by the spectral spectrum.

  The short wavelength cut translucent film in the present invention preferably has a transmittance at a wavelength of 300 nm of 5% or less, more preferably 3% or less, and particularly preferably 1% or less. This is because when the average transmittance in the short wavelength region is in the above range, a semicircular member with a smoother top can be formed.

The short wavelength cut translucent film in the present invention preferably has a transmittance at a wavelength of 380 nm of 35% or more, particularly preferably within a range of 40% or more, particularly within a range of 45% or more. It is preferable that It is because the transmittance | permeability in the said wavelength is in the said range, and the inside hardening of the photosensitive resin layer and adhesiveness with a board | substrate can be made more favorable.
In addition, the height of the member formed by the transparent region made of the transparent substrate can be made sufficiently different.

  The average transmittance within the wavelength range of 350 nm to 450 nm of the short wavelength cut translucent film in the present invention is preferably within the range of 35% to 65%, and more preferably within the range of 45% to 55%. Preferably there is. This is because a semicircular member whose top is smoother can be formed.

The material constituting the short-wavelength cut translucent film used in the present invention may be any material that satisfies the above-described spectral spectrum, but one of the first translucent film forming material and the second translucent film forming material is In the case where the titanium material is the above and the other is the chromium material, a compound containing Ti and W, a compound containing Ti and Mo, and titanium oxide can be preferably used. In particular, titanium oxide is preferably used. it can. This is because the short-wavelength cut translucent film is made of the above-described material, so that it is easy to provide the above-described spectral spectrum.
Moreover, when the semi-transparent film forming material is the chromium-based material and the titanium-based material, the first semi-transparent film and the second semi-transparent film can be easily formed by using the above-described materials. Because.

  In the present invention, when used as a material constituting the short wavelength cut translucent film, the content of Ti in the compound containing Ti and W is preferably 33% by mass or more. Moreover, as content of Ti in the compound containing Ti and Mo, it is preferable that it is 33 mass% or more. This is because it is easy to have the above-described spectral spectrum.

As a member formed using the short wavelength cut translucent film in the present invention, if the gradation mask of the present invention is used, the height and shape are different, and the member is formed of a member formed in a lump. Good examples include various members.
Specifically, when each member constituting the color filter is formed using the gradation mask, examples of the member include a colored layer, a light shielding portion, a spacer, an alignment control protrusion, an overcoat layer, and the like. it can.
In the present invention, the alignment control protrusion is particularly preferable. As described above, the short wavelength cut translucent film can form a semicircular member having a smooth top. For this reason, this is because it is suitable for forming an alignment control protrusion, which is usually required to be a semicircular member having a smooth top.

(D) Others The semitransparent film used in the present invention may have a negatively inclined semitransparent film whose transmittance decreases as the wavelength increases.

As a material constituting such a negatively inclined semitransparent film, when one of the first translucent film forming material and the second translucent film forming material is the titanium-based material and the other is the chromium-based material Alternatively, chromium oxynitride can be used.
The element ratio of Cr, O, and N of chromium oxynitride used for forming such a negatively inclined translucent film is within the range of Cr: 40% to 60%, and within the range of O: 1% to 10%. N: preferably in the range of 35% to 55%, especially Cr: in the range of 45% to 55%, O: in the range of 1% to 5%, N: in the range of 40% to 50% It is preferable that

  The average transmittance of the negatively inclined semitransparent film in the present invention within a wavelength range of 250 nm to 600 nm is preferably within a range of 10% to 60%. If the average transmittance is less than the above range, in the pattern formation using the gradation mask of the present invention, the difference in transmittance between the semi-transparent region and the light shielding region may be difficult to occur, and the average transmittance is within the above range. This is because if it exceeds, the difference in transmittance between the negatively inclined semitransparent region and the transmissive region, which is composed only of the transparent substrate and the negatively inclined semitransparent film, may be difficult to occur.

(3) The first translucent film and the second translucent film The translucent films (first translucent film and second translucent film) used in the present invention are formed on the transparent substrate. What is necessary is just to have the area | region directly formed on the transparent substrate, and it may be formed on the said light shielding film.

  The film thickness of the translucent film used in the present invention is not particularly limited as long as it can have a desired transmittance, and is appropriately set depending on the material and the like. It can be about 20 nm. Since the transmissivity of the translucent film varies depending on the film thickness, the desired transmissivity can be obtained by controlling the film thickness. Further, when the second translucent film forming material constituting the translucent film contains oxygen, nitrogen, carbon, etc., the transmittance varies depending on the composition, so that the desired thickness can be controlled by controlling the film thickness and the composition at the same time. Transmittance can be realized.

  The layer structure of the translucent film used in the present invention may be a single layer or a plurality of layers each made of the same material.

  As a method for forming a translucent film in the present invention, for example, a physical vapor deposition method (PVD) such as a sputtering method, an ion plating method, or a vacuum vapor deposition method is used.

2. Transparent substrate The substrate generally used for a photomask can be used for the transparent substrate used for this invention. For example, optically polished low expansion glass such as borosilicate glass and aluminoborosilicate glass, quartz glass, synthetic quartz glass, Pyrex (registered trademark) glass, soda lime glass, white sapphire and other non-flexible transparent rigid materials Alternatively, a flexible transparent material having flexibility such as a transparent resin film and an optical resin film can be used. In the present invention, quartz glass is particularly preferable. This is because quartz glass is a material having a low coefficient of thermal expansion and is excellent in dimensional stability and characteristics in high-temperature heat treatment.
In addition, the transparent substrate used in the present invention may have a surface coated with another material as necessary.

3. Light-shielding film The light-shielding film used in the present invention is directly formed on the transparent substrate and does not substantially transmit exposure light.
Here, “directly formed on the transparent substrate” usually means that the light-shielding film is in contact with the transparent substrate without interposing another layer between the light-shielding film and the transparent substrate. However, it may be formed between the transparent substrate and other layers as necessary.

As a light shielding film forming material constituting such a light shielding film, a material generally used for a light shielding film used for a photomask can be used. In the present invention, the light shielding film forming material is preferably the same kind of material as either the first semitransparent film forming material or the second semitransparent film forming material. It is preferable that it is the same material as any one of a semi-transparent film forming material and a 2nd semi-transparent film forming material. Since the light-shielding film forming material is the same as one of the first semi-transparent film forming material and the second semi-transparent film forming material, it can be etched with the same etching solution, thereby reducing the cost. It is because it can plan.
Note that the same type of material is a material having the same metal element as the main component and the same tendency of chemical resistance against the etching solution.
As a specific example of the case where the light shielding film forming material is the same kind of material as the semitransparent film forming material, when the semitransparent film forming material is the chromium material or the titanium material, the light shielding film forming material is used. Can be mentioned as the chromium-based material or the titanium-based material.

  In addition, the light shielding film forming material used in the present invention is preferably the above-mentioned chromium-based material from the viewpoint of light shielding properties, and particularly preferably chromium.

The light-shielding film used in the present invention may be covered with the semitransparent film (the first semitransparent film and / or the second semitransparent film) or may not be covered with the semitransparent film. May be.
In the present invention, in particular, when the light shielding film forming material is the same kind of material as either the first semitransparent film forming material or the second semitransparent film forming material, the first semitransparent film is used. It is preferable that it is covered with at least one of the second translucent film, and it is particularly preferable that it is covered with the same kind of material as the light shielding film forming material. By covering the light shielding film with the semitransparent film, the light shielding film can be covered with a resist when the semitransparent film is formed. Therefore, it can prevent contacting with the etching liquid used when forming the said semi-transparent film | membrane. For this reason, the light shielding film can be prevented from being etched by the etching solution used when the semitransparent film is formed by etching, so that the light shielding film with high pattern accuracy can be obtained.
Further, by being covered with a translucent film made of the same kind of material as the light shielding film forming material, it is possible to more effectively prevent contact with the etching solution.

  The light shielding film used in the present invention may be a single layer or may be composed of a plurality of layers.

  The light-shielding film used in the present invention substantially does not transmit exposure light, and the average transmittance at the exposure wavelength is preferably 0.1% or less.

  The thickness of the light-shielding film used in the present invention is not particularly limited. For example, in the case of a chromium film, it can be about 50 nm to 150 nm.

  In addition, the light shielding film may have a low reflection function. Since the low reflection function can prevent irregular reflection of exposure light, a clearer pattern can be formed. In order to add a low reflection function to the light shielding film, for example, a chromium compound such as chromium oxide for preventing reflection of exposure light may be contained on the surface of the light shielding film. In this case, the light shielding film may be formed by an inclined interface in which the content component gradually changes toward the surface.

4). Gradation mask The gradation mask of the present invention has the transparent substrate, the light shielding film, the first semitransparent film, and the second semitransparent film, and includes the transmission region, the light shielding region, the first semitransparent region, And at least the second translucent region.

(1) Region The gradation mask of the present invention comprises a transmissive region, a light shielding region, a first semitransparent region, and a second semitransparent region.

The transmission region provided in the gradation mask of the present invention is a region made of a transparent substrate, and is a region not covered with the first semitransparent film, the second semitransparent film, and the light shielding film.
Such a transmission region is usually composed only of the transparent substrate, but may have other layers as long as it does not greatly affect the transmittance.

The light shielding region provided in the gradation mask of the present invention includes at least the transparent substrate and the light shielding film.
Such a light shielding region may include the first translucent film or the second translucent film. In addition to the transparent substrate, the first semi-transparent film, the second semi-transparent film, and the light-shielding film, other layers may be included as long as the transmittance is not greatly affected.

The first semitransparent region provided in the gradation mask of the present invention is a region which is composed of the transparent substrate and the first semitransparent film and is not covered with the second semitransparent film and the light shielding film.
Such a first semi-transparent region is usually composed only of the transparent substrate and the first semi-transparent film, but may include other layers as long as the transmittance is not greatly affected. good.

The second semitransparent region provided in the gradation mask of the present invention is a region which is composed of the transparent substrate and the second semitransparent film and is not covered with the first semitransparent film and the light shielding film.
Such a second semi-transparent region is usually composed only of the transparent substrate and the second semi-transparent film, but may include other layers as long as it does not greatly affect the transmittance. good.

The gradation mask of the present invention includes at least a transmission region, a light shielding region, a first semitransparent region, and a second semitransparent region. If necessary, the transparent substrate, the first semitransparent film, You may provide the semi-transparent film | membrane laminated area | region which consists of two semi-transparent films | membranes.
Such a semi-transparent film lamination region is usually composed only of the transparent substrate, the first semi-transparent film and the second semi-transparent film, but other layers may be used as long as the transmittance is not greatly affected. It may be included.

(2) Others The gradation mask of the present invention may have at least the transparent substrate, the light-shielding film, the first semi-transparent film, and the second semi-transparent film, but has other configurations as necessary. It may be a thing.
Specific examples of such other configurations include a low reflection layer formed on the light shielding film and capable of preventing halation when using the gradation mask of the present invention. Examples of the low reflection layer include films of chromium oxide, chromium nitride, chromium oxynitride, and the like. When the light shielding film is a chromium-based film, these films can be etched simultaneously with the etching of the light shielding film.

  The gradation mask manufacturing method of the present invention may be any method that can form the transparent substrate and the semi-transparent film with high accuracy, and a method generally used for manufacturing a gradation mask is used. be able to. Specifically, the method described in the section “B. Manufacturing method of gradation mask” described later can be used.

  The application of the gradation mask of the present invention can be used for manufacturing various products manufactured through an exposure process, such as a lithography method. Especially, it is suitable for the manufacture of display devices such as liquid crystal display devices, organic EL display devices, and plasma display panels, and particularly for the manufacture of display devices that require high-precision and high-quality formation of members having different heights and shapes. Can be used.

B. Next, a method for manufacturing a gradation mask according to the present invention will be described. The method for producing a gradation mask of the present invention comprises forming a pattern of the light shielding film forming layer of a laminate having a transparent substrate and a light shielding film forming layer formed on the transparent substrate and made of a light shielding film forming material. By etching, a light shielding film forming step for forming a light shielding film, and a first semitransparent film forming layer made of a first semitransparent film forming material was formed on the transparent substrate so as to cover the light shielding film. Thereafter, a first translucent film forming step of forming the first translucent film directly formed on the transparent substrate by etching the first translucent film forming layer into a pattern, and on the transparent substrate In addition, a second semi-transparent film forming layer made of a second semi-transparent film forming material having a resistance to an etching solution different from that of the first semi-transparent film forming material so as to cover the light shielding film and the first semi-transparent film. After forming, the second semi-transparent film forming layer The second translucent film formed directly on the transparent substrate by etching in a pattern with an etchant for the second translucent film forming material, which is an etchant having resistance to the first translucent film forming material And a second translucent film forming step for forming the film.

A method of manufacturing such a gradation mask of the present invention will be described with reference to the drawings. FIG. 7 is a process diagram showing an example of a method for manufacturing a gradation mask according to the present invention. As illustrated in FIG. 7, the gradation mask manufacturing method of the present invention prepares a laminate 20 having a transparent substrate 1 and a light shielding film forming layer 22 formed on the transparent substrate 1, and then Then, a resist 25 is formed in a region on the light shielding film forming layer 22 corresponding to the region where the light shielding film is to be formed (FIG. 7A), and etching of the light shielding film forming layer 22 and removal of the resist 25 are performed. In this order, the light shielding film 2 is formed (FIG. 7B).
Next, as shown in FIG. 7C, a first semi-transparent film forming material that is the same kind of material as the light shielding film forming material is formed on the transparent substrate 1 so as to cover the light shielding film 2. A semi-transparent film forming layer 23 is laminated, and then a resist 25 is formed in a region where the first semi-transparent film is to be formed, and then the first semi-transparent film forming layer 23 is formed on the first semi-transparent film forming layer. The first semitransparent film 3 is formed on the transparent substrate 1 and on the entire surface of the light-shielding film 2 by etching with an etching solution capable of etching the material and further removing the resist 25 in this order. (FIG. 7D).

Subsequently, as shown in FIG. 7 (e), the light shielding film forming material and the first semitransparent film forming material are resistant to an etching solution so as to cover the light shielding film 2 and the first semitransparent film 3. A second semitransparent film forming layer 24 made of a second semitransparent film forming material, which is a different material, is laminated, and then a resist 25 is formed in a region where the second semitransparent film is formed. Next, the second semi-transparent film forming layer 24 is etched with an etching solution for the second semi-transparent film forming material with which the light-shielding film forming material and the first semi-transparent film forming material are resistant, and the resist 25 is removed. To form a second translucent film 4, a transparent region 11 made of the transparent substrate 1, a light-shielding region 12 including at least the transparent substrate 1 and the light-shielding film 2, the transparent substrate 1 and the first substrate 1. A gradation mask 10 including a first semitransparent region 13 made of a semitransparent film 3 and a second semitransparent region 14 made of the transparent substrate 1 and the second semitransparent film 4 is formed (FIG. 7). (F)).
Here, FIGS. 7A to 7B are light shielding film forming steps, FIGS. 7C to 7D are first semitransparent film forming steps, and FIGS. 7E to 7F are second semitransparent steps. It is a film forming process.

Further, as another example of the method of manufacturing the gradation mask of the present invention, as illustrated in FIG. 8, the transparent substrate 1 and the light shielding film forming layer 22 formed on the transparent substrate 1 are provided. And then a resist 25 is formed in the region on the light shielding film forming layer 22 corresponding to the region where the light shielding film is to be formed (FIG. 8A), and then etched with an etching solution. Then, the light shielding film 2 is formed (FIG. 8B).
Thereafter, as shown in FIG. 8C, the first semi-transparent film made of the first semi-transparent film forming material, which is a material having different resistance to the etching solution from the light shielding film forming material so as to cover the light shielding film 2 A forming layer 23 is laminated, and then a resist 25 is formed in a region where the first translucent film is formed. Next, the first semi-transparent film forming layer 23 is etched with an etching solution with which the light-shielding film forming material is resistant, and the resist 25 is removed so that the transparent substrate 1 and the light-shielding portion 2 are partially removed. A first translucent film 3 is formed on the substrate (FIG. 8D).

Subsequently, as shown in FIG. 8E, a second semi-transparent film-forming material, which is the same material as the light-shielding film-forming material, covers the light-shielding film 2 and the first semi-transparent film 3. After laminating the two semitransparent film forming layers 24, the first semitransparent film 3 out of the region where the second semitransparent film is directly formed on the transparent substrate and the region where the light shielding film 2 is formed. A resist 25 is formed on the uncoated region. Next, the second semi-transparent film forming layer 24 is etched with a second semi-transparent film forming material etchant, which is an etchant with which the first semi-transparent film forming material is resistant, and the resist 25 is further removed. As a result, a second semi-transparent film 4 is formed on the transparent substrate 1 and on a region of the light-shielding film 2 that is not covered with the first semi-transparent film 3. 11, the transparent substrate 1, the light shielding film 2 and the light shielding region 12 comprising the second semitransparent film, the first semitransparent region 13 comprising the transparent substrate 1 and the first semitransparent film 3, and the transparent A gradation mask 10 including the substrate 1 and the second translucent region 14 made of the second translucent film 4 is formed.
Here, FIGS. 8A to 8B are light shielding film forming steps, FIGS. 8C to 8D are second semitransparent film forming steps, and FIGS. 8E to 8F are first semitransparent. It is a film forming process.

According to the present invention, a transmission region composed of the transparent substrate, a light shielding region including at least the transparent substrate and the light shielding film, a first semitransparent region composed of the transparent substrate and the first semitransparent film, and the transparent A gradation mask including a substrate and a second semi-transparent region made of the second semi-transparent film can be formed.
Further, the light shielding film forming step is performed before the first semitransparent film forming step and the second semitransparent film forming step, that is, the light shielding film forming layer is formed by only one etching. Thus, the light shielding film can be formed without being affected by the positional deviation due to the alignment accuracy. Further, since the light shielding film is usually used for forming the main pattern of the gradation mask, it can be a mask with excellent pattern accuracy.
Further, the first translucent film forming step and the second translucent film forming step are provided, and the first translucent film and the second translucent film are independently formed. Therefore, the first translucent film is formed. The spectral spectrum, transmittance, and the like of the film and the second translucent film can be easily made different. For this reason, it is possible to obtain a mask that can collectively form members having different heights and shapes with a high degree of freedom.

The gradation mask manufacturing method of the present invention includes at least the light shielding film forming step, the first semitransparent film forming step, and the second semitransparent film forming step.
Hereafter, each process of the manufacturing method of the gradation mask of this invention is demonstrated in detail.

1. Light-shielding film forming step The light-shielding film forming step in the method for producing a gradation mask of the present invention includes a transparent substrate and a light-shielding film-forming layer formed on the transparent substrate and made of a light-shielding film-forming material. This is a step of forming the light shielding film by etching the light shielding film forming layer into a pattern.
The light-shielding film formed in this step is the same as that described in the above section “A. Tone mask”, and will not be described here.

  In this step, since the light shielding film can be formed, a light shielding region including at least the transparent substrate and the light shielding film can be formed.

(A) Laminated body The laminated body used for this process has a transparent substrate and the layer for light shielding film formation.
As the light-shielding film forming material constituting such a transparent substrate and the light-shielding film forming layer, it can be the same as the transparent substrate and the light-shielding film forming material described in the above section “A. Tone mask”. The description here is omitted.

  The thickness of the light shielding film forming layer formed in this step can be the same as the thickness of the light shielding film to be formed. Specifically, it may be the same as the film thickness of the light-shielding film described in the section “A. Tone mask”.

  The light-shielding film forming layer formed in this step may be a single layer or a plurality of layers.

  The light shielding film forming layer in this step may be formed by any method that can form the light shielding film forming layer with a uniform thickness on the transparent substrate. And physical vapor deposition (PVD) such as vacuum evaporation.

(B) Etching method In this step, the light shielding film forming layer of the laminate is etched into a pattern to form a light shielding film, and a method generally used for forming a light shielding film in a gradation mask is used. Can be used.
Specifically, there is a method of forming a resist in a pattern in a region where the light shielding film is to be formed, etching the light shielding film forming material with an etching solution capable of etching, and then removing the resist. it can.

  In this step, as a method of forming the resist in a pattern, it can be formed by applying a resist material to form a resist film, exposing to a pattern, and further developing.

  As the resist material used in this step, either a positive resist material (one that dissolves the light-irradiated portion) or a negative resist material (one that hardens the light-irradiated portion) can be used. Examples of the positive resist material include a chemically amplified resist using a novolac resin as a base resin. Examples of the negative resist material include a chemically amplified resist based on a crosslinked resin, specifically, a chemically amplified resist obtained by adding a crosslinking agent to polyvinylphenol and further adding an acid generator.

  In this step, as a method for forming the resist film by coating the resist material, a general coating method can be used, for example, spin coating method, casting method, dipping method, bar coating method, blade coating method. The method, roll coating method, gravure coating method, flexographic printing method, spray coating method and the like can be used.

In this step, as a method of exposing the resist film in a pattern, an electron beam drawing method used for normal photomask drawing, a laser drawing method, or the like can be used.
Moreover, as a developing method of the resist film after exposure, a general developing method can be used.

In this step, the light-shielding film forming material etching solution that can etch the light-shielding film forming layer may be any etching solution that can etch the light-shielding film forming material. The methods generally used in the above can be used.
Specifically, the light-shielding film forming material etching solution varies depending on the material used. However, when the light-shielding film forming material is the chromium-based material, cerium nitrate second ammonium is used. A mixed solution of perchloric acid or a mixed solution of sulfuric acid and phosphoric acid can be used, and among them, a mixed solution of cerium nitrate second ammonium solution and perchloric acid can be preferably used.
Moreover, when the light shielding film forming material is the titanium material, hydrofluoric acid or a mixed solution of potassium hydroxide and hydrogen peroxide can be used. The mixed solution can be preferably used.

  In this step, after removing the light-shielding film forming layer and forming the light-shielding film, a general removal method can be used as a method for removing the resist formed in a pattern. Specifically, In general, a method of ashing by oxygen plasma treatment or cleaning with an organic alkali solution can be exemplified.

2. First translucent film forming step The first translucent film forming step in the gradation mask manufacturing method of the present invention includes a first translucent film forming material that covers the transparent substrate so as to cover the light shielding film. This is a step of forming a first translucent film directly formed on the transparent substrate by forming the first translucent film forming layer and then etching the first translucent film forming layer into a pattern. .
The first semi-transparent film formed by this step and the first semi-transparent film forming material used are the same as those described in the above section “A. Tone mask”, and are therefore described here. Is omitted.

In this step, since the first translucent film is formed directly on the transparent substrate, a first translucent region composed of the transparent substrate and the first translucent film can be formed.
In addition, the first translucent film forming material is different in resistance to the etching solution from the second translucent film forming material, and therefore, in the second translucent film forming process described later, the first translucent film forming material is used. The film may not be etched by the second translucent film forming material etching solution. For this reason, the first semitransparent film can be formed with high accuracy.

  As a method of forming such a first translucent film, a first translucent film forming layer made of the first translucent material is formed, and then the first translucent film forming layer is formed with an etching solution. Any pattern etching method may be used, and a method generally used for forming a translucent film in a gradation mask can be used.

  In this step, the first semitransparent film forming layer may be formed by any method that can form the first semitransparent film forming layer with a desired film thickness. Since it can be the same as the method described in the section of “Light-shielding film forming step”, description thereof is omitted here.

  The thickness of the first semitransparent film forming layer formed in this step can be the same as the thickness of the first semitransparent film to be formed. Specifically, it may be the same as the film thickness of the first translucent film described in the section “A. Tone mask”.

In this step, the first translucent film forming layer is etched to form the first translucent film, and the first translucent film directly formed on the transparent substrate can be formed. If it is good.
Specifically, a resist is formed in a region where the first semi-transparent film is to be formed, and then the first semi-transparent film forming material is etched with an etching solution that can etch, and then the resist is removed. A method can be mentioned.
The method for forming the resist and the method for removing the resist can be the same as the contents described in the above section “1.

  In this step, the etchant used for etching the first translucent film forming layer may be any one that can etch the first translucent film forming layer. Specifically, Depending on the material used, when the first translucent film-forming material is the chromium-based material or the titanium-based material, it is the same as the etching liquid used when etching the light-shielding film-forming material. It can be.

In this step, the region for forming the resist may be any region as long as the first semitransparent film can be directly formed on the transparent substrate.
Specifically, it may be formed in a region where the first semi-transparent film is to be formed, and may be a region where the light shielding film is formed.
In this step, when the light shielding film forming material is the same kind of material as the first translucent film forming material, the resist is preferably formed in the entire region where the light shielding film is formed. By forming a resist in such a region, the light shielding film can be prevented from coming into contact with the etching solution. For this reason, this process can effectively prevent the light shielding film from being etched, and a light shielding film with good pattern accuracy can be obtained. Further, at the portion where the first semi-transparent region and the light-shielding region are in contact with each other, the first semi-transparent film can be a continuous film covering the light-shielding film including the boundary portion of the first semi-transparent region. As a result, the first semi-transparent film can be formed without depending on the alignment accuracy with the light-shielding film, and even in that case, the boundary between the first semi-transparent region and the light-shielding region is the light-shielding film. This is because the edges of both regions can be formed with high accuracy.
In addition, since the light shielding film can be formed with high pattern accuracy and the edges of both regions can be formed with high precision, for example, as shown in FIG. Are formed and the first translucent area is divided by the light shielding area, as shown in FIGS. 2, 3 and 4B, which are already described, are separated by independent members, that is, areas corresponding to the light shielding area. This is because the formed member can be formed with high accuracy.

  In addition, when the light shielding film forming material and the first translucent film forming material are materials having different resistances to the etching solution, it is preferable that the resist is also formed on at least a part of the light shielding film. More specifically, it is preferable that the first translucent film is formed also on the first semi-transparent region and the light-shielding region adjacent thereto at the portion where the first semi-transparent region and the light-shielding region are in contact with each other. In this case, the first semi-transparent film can be a continuous film that covers the light-shielding film including the boundary of the first semi-transparent region, so that the alignment can be facilitated. This is because the edge of the region can be formed with high accuracy. Moreover, it is because an independent member can be formed with sufficient precision from such a thing.

3. Second translucent film forming step The second translucent film forming step in the method of manufacturing a gradation mask of the present invention includes the first semitransparent film so as to cover the light shielding film and the first translucent film on the transparent substrate. After forming the second translucent film forming layer made of the second translucent film forming material having different resistance to the etching solution from the transparent film forming material, the second translucent film forming layer is formed into the first translucent film. This is a step of forming a second semitransparent film directly formed on the transparent substrate by etching in a pattern with an etching solution for a second semitransparent film forming material, which is an etchant with which the film forming material is resistant. .
The second translucent film formed by this step and the second translucent film forming material used can be the same as those described in the above section “A. Tone mask”. The description in is omitted.

In this step, a second translucent film formed directly on the transparent substrate can be formed. For this reason, the 2nd translucent area | region which consists of the said transparent substrate and a 2nd translucent film | membrane can be formed.
Further, by using the second translucent film forming material and the second translucent film forming material etching solution, only the second translucent film forming material can be etched. For this reason, the first translucent region and the second translucent region can be formed with high accuracy.

  As a method of forming such a second translucent film, a second translucent film forming layer made of the second translucent film forming material is formed, and then the second translucent film forming material etching solution is formed. Any method generally used for forming a translucent film in a gradation mask can be used.

  In this step, the second semitransparent film forming layer may be formed by any method that can form the second semitransparent film forming layer with a desired film thickness. Since it can be the same as the method described in the section “Light-shielding film forming step”, the description is omitted here.

  The thickness of the second semitransparent film forming layer formed by this step can be the same as the thickness of the second semitransparent film to be formed. Specifically, it may be the same as the film thickness of the second translucent film described in the section “A. Tone mask”.

In this step, the second semi-transparent film forming layer was etched with the second semi-transparent film forming material etching solution to form the second semi-transparent film. The second semi-transparent film was formed directly on the transparent substrate. Any method that can form the second translucent film may be used.
Specifically, there may be mentioned a method of forming a resist in a region where the second semitransparent film is to be formed, then etching with the second semitransparent film forming material etching solution, and then removing the resist. it can.
The method for forming the resist and the method for removing the resist can be the same as the contents described in the above section “1.

The second semitransparent film forming material etchant in this step is an etchant that is resistant to the first semitransparent film forming material and can etch the second translucent film forming material.
Specifically, the second semitransparent film forming material etching solution varies depending on the material used, but the first semitransparent film forming material is the chromium-based material, and the second semitransparent film forming material is the second semitransparent film forming material. When the transparent film forming material is a titanium-based material, hydrofluoric acid or a mixed solution of potassium hydroxide and hydrogen peroxide can be used, and a mixed solution of potassium hydroxide and hydrogen peroxide is preferable. Can be used.
Further, when the first translucent film forming material is the titanium-based material and the second translucent film forming material is a chromium-based material, a mixed solution of cerium nitrate second ammonium and perchloric acid, A mixed solution of sulfuric acid and phosphoric acid can be used, and among them, a mixed solution of cerium nitrate second ammonium solution and perchloric acid can be preferably used.

In this step, the region where the resist is formed may be any as long as it can form the second semi-transparent film directly formed on the transparent substrate.
Specifically, it may be formed in a region where the second semi-transparent region is desired to be formed, and may include a region where the light shielding film is formed.
In this step, in particular, when the light shielding film forming material is the same type of material as the second semitransparent film forming material, the first semitransparent film is covered in the region where the light shielding film is formed. It is preferable that a resist is formed in a region other than the region where the resist is formed.
By forming a resist in such a region, the light shielding film can be prevented from coming into contact with the etching solution. For this reason, this process can effectively prevent the light shielding film from being etched, and a light shielding film with good pattern accuracy can be obtained. Further, at the portion where the second semi-transparent region and the light-shielding region are in contact, the second semi-transparent film can be a continuous film covering the light-shielding film including the boundary portion of the second semi-transparent region. As a result, the second semitransparent film can be formed without depending on the alignment accuracy with the light shielding film, and even in that case, the boundary between the second semitransparent area and the light shielding area is the light shielding film. This is because the edges of both regions can be formed with high accuracy.
Furthermore, since the light shielding film can be formed with high pattern accuracy and the edges of both regions can be formed with high accuracy, independent members can be formed with high accuracy.

  Further, when the light shielding film forming material and the second semitransparent film forming material are materials having different resistances to the etching solution, the resist is at least a part of the light shielding film, more specifically, the second semitransparent region. It is preferable that the second semi-transparent film is also formed on the second semi-transparent region and the adjacent light-shielding region at a portion where the light-shielding region contacts. In this case, since the second translucent film can be a continuous film covering the light shielding film including the boundary of the second translucent region, the alignment can be facilitated. This is because the edges of both regions can be formed with high accuracy. Moreover, it is because an independent member can be formed with sufficient precision from such a thing.

4). Method for Manufacturing Tone Mask The method for manufacturing a tone mask of the present invention includes at least the above-described light shielding film forming step, first semitransparent film forming step, and second semitransparent film forming step. Depending on the situation, other processes may be included.
Examples of such other steps include a low reflection layer forming step of forming a low reflection layer on the light shielding film.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be specifically described using examples and comparative examples.

[Example 1]
1. Production of gradation mask Commercially available photoresist (manufactured by Tokyo Ohka Kogyo Co., Ltd.) on a conventional mask blank in which a chromium film (light-shielding film) is formed with a thickness of 100 nm on an optically polished 390 mm × 610 mm synthetic quartz substrate ip-3500) is applied at a thickness of 600 nm and baked on a hot plate heated to 120 ° C. for 15 minutes, and then a desired light shielding film intermediate pattern is formed with a photomask laser drawing apparatus (LRS11000-TFT3 manufactured by Micronics). Drawn.
Next, development was performed with a dedicated developer (NMD3 manufactured by Tokyo Ohka Kogyo Co., Ltd.) to obtain a resist pattern for a light shielding film.
Next, the resist pattern was used as an etching mask, the chromium film was etched, and the remaining resist pattern was peeled off to obtain a light-shielding film having a desired pattern. A commercially available cerium nitrate wet etchant (MR-ES manufactured by The Inktec Co., Ltd.) was used for etching the chromium film. The etching time for the chromium film was 60 seconds.
Thereafter, the substrate on which the light shielding film pattern was formed was subjected to pattern dimension inspection, pattern defect inspection, pattern correction as needed, and washed well.

  Next, a short wavelength cut translucent film forming layer made of titanium oxide was formed by sputtering under the following conditions.

<Film formation conditions>
-Gas flow ratio Ar: O ₂ = 4: 1
・ Power: 1.3kW
・ Gas pressure: 3.5mTorr
The film thickness of the short wavelength cut translucent film forming layer was 20 nm.

Next, after forming a resist pattern in a region where the short wavelength cut semi-transparent film is to be formed (the region where the short wavelength cut semi-transparent region is formed and where the light shield film is formed) by the same method as the formation of the light shielding film, The layer for forming a short wavelength cut translucent film was etched, and the remaining resist pattern was peeled off to obtain a desired short wavelength cut translucent film (first translucent film). For etching the layer for forming a short-wavelength cut translucent film, a mixed solution of potassium hydroxide and hydrogen peroxide (a solution of potassium hydroxide aqueous solution, hydrogen peroxide solution and water mixed at 1:16:32) is used. It was. The etching time of the short wavelength cut translucent film forming layer was 60 seconds.
Thereafter, the substrate on which the short wavelength cut translucent film and the light shielding film were formed was subjected to pattern dimension inspection, pattern defect inspection, and pattern correction as necessary.

  Next, a flat translucent film forming layer made of chromium nitride (Cr: content 60%, N: content 40%) was formed by sputtering under the following conditions.

<Film formation conditions>
・ Gas flow ratio Ar: N ₂ = 4: 1
・ Power: 1.3kW
・ Gas pressure: 3.5mTorr
The film thickness of the flat translucent film forming layer was 10 nm.

Next, by forming a resist pattern in a region where the flat semitransparent film is to be formed (region where the flat semitransparent region is to be formed) by the same method as the formation of the light shielding film, the flat semitransparent film forming layer is etched, Further, the desired resist pattern was peeled off to obtain a desired flat translucent film (second translucent film).
A commercially available cerium nitrate wet etchant (MR-ES manufactured by The Inktec Co., Ltd.) was used for etching the flat translucent film forming layer. The etching time of the flat translucent film forming layer was 60 seconds.
In the short wavelength cut semi-transparent film, the region where the resist pattern was not formed was not etched by the etching solution used for etching the flat semi-transparent film forming layer.

Thereafter, the substrate on which the short wavelength cut translucent film, the flat translucent film, and the light shielding film were formed was subjected to pattern dimension inspection, pattern defect inspection, and pattern correction as necessary.
Thereby, the gradation mask having the first semi-transparent film (short wavelength cut semi-transparent film) and the second semi-transparent film (flat semi-transparent film) as shown in FIG. 1 was obtained.
In the obtained gradation mask, the transmittance of the i-line (365 nm) of the first translucent film (short wavelength cut translucent film) is 50%, and the second translucent film (flat translucent film) is 50%. The transmittance of i-line (365 nm) was 30%.

2. Production of Color Filter Using Tone Mask A glass substrate (Corning 1737 glass) having a size of 300 mm × 400 mm and a thickness of 0.7 mm was prepared. After this substrate was washed according to a conventional method, a chromium thin film (thickness 1500 mm) was formed on the entire surface of one side of the substrate by sputtering. A positive-type photosensitive resist (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied onto the chromium thin film, and exposed and developed through a predetermined mask to form a resist pattern. Next, using this resist pattern as a mask, the chromium thin film was etched to form a black matrix having a line width of 20 μm and a pitch of 100 μm.

  Next, a negative photosensitive resin composition for a red pattern, a negative photosensitive resin composition for a green pattern, and a negative photosensitive resin composition for a blue pattern having the following compositions were prepared.

<Negative photosensitive resin composition for red pattern>
Red pigment (Ciba Specialty Chemicals chromophthal red A2B) 4.8 parts by weight Yellow pigment (BASF Pariotor Yellow D1819) 1.2 parts by weight Dispersant (Dispervic 161 manufactured by BYK Chemie) 3 1.0 part by weight / monomer (SR399 manufactured by Sartomer) 4.0 parts by weight Polymer I 5.0 parts by weight initiator (Irgacure 907 manufactured by Ciba Specialty Chemicals) 1.4 parts by weight initiator (2, 2′-bis (o-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole) 0.6 part by weight / solvent (propylene glycol monomethyl ether acetate) 80.0 parts by weight

<Negative photosensitive resin composition for green pattern>
Green pigment (Avisia Monastral Green 9Y-C) 4.2 parts by weight Yellow pigment (BASF Paliotor Yellow D1819) 1.8 parts by weight Dispersant (Bicchemy Disperbic 161) 3.0 Parts by weight / monomer (SR399, manufactured by Sartomer) 4.0 parts by weight, polymer I 5.0 parts by weight, initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals) 1.4 parts by weight, initiator (2,2 ′ -Bis (o-chlorophenyl) -4,5,4 ', 5'-tetraphenyl-1,2'-biimidazole) 0.6 parts by weight / solvent (propylene glycol monomethyl ether acetate) 80.0 parts by weight

<Negative photosensitive resin composition for blue pattern>
Blue pigment (BASF Heliogen Blue L6700F) 6.0 parts by weight Pigment derivative (Abyssia Solsperse 5000) 0.6 parts by weight Dispersant (Bic Chemie Dispersic 161) 2.4 parts by weight Monomer (SR399, manufactured by Sartomer) 4.0 parts by weight, Polymer I, 5.0 parts by weight, initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals) 1.4 parts by weight, initiator (2,2'-bis (o -Chlorophenyl) -4,5,4 ', 5'-tetraphenyl-1,2'-biimidazole) 0.6 parts by weight / solvent (propylene glycol monomethyl ether acetate) 80.0 parts by weight

  The polymer I is based on 100 mol% of a copolymer of benzyl methacrylate: styrene: acrylic acid: 2-hydroxyethyl methacrylate = 15.6: 37.0: 30.5: 16.9 (molar ratio). 2-methacryloyloxyethyl isocyanate was added at 16.9 mol%, and the weight average molecular weight was 42500.

  Next, a negative photosensitive resin composition for red pattern is applied by spin coating so as to cover the black matrix on the glass substrate, exposed and developed through a photomask for red pattern, and the red pattern is formed. Formed. The red pattern was rectangular (100 μm × 300 μm).

Then, the green pattern and the blue pattern were formed by the same operation using the negative photosensitive resin composition for the green pattern and the negative photosensitive resin composition for the blue pattern. As a result, a colored layer in which a red pattern, a green pattern, and a blue pattern were arranged was formed.
Next, a transparent electrode layer (thickness 1500 mm) made of indium tin oxide (ITO) was formed by sputtering so as to cover the black matrix and the colored layer.

  Next, a negative photosensitive resin composition (Optomer NN850 manufactured by JSR) was applied on the transparent electrode layer by spin coating, dried under reduced pressure, and prebaked at 100 ° C. for 3 minutes. Then, it exposed on the following conditions through said gradation mask.

<Exposure conditions>
・ Exposure amount: 100 mJ / cm ² (i-line conversion)
・ Exposure gap: 150μm

  Next, development was performed using an aqueous potassium hydroxide solution, followed by heat treatment at 230 ° C. for 30 minutes to produce a color filter having three convex patterns on the transparent electrode.

[Example 2]
1. Production of gradation mask In the same manner as in Example 1, a light-shielding film having a desired pattern is formed, and then a short-wavelength cut semi-transparent film (first semi-transparent film) having a film thickness of 70 nm is formed. did.

Next, after forming a forwardly inclined semitransparent film forming layer made of chromium oxynitride (O: content 20%, Cr: content 60%, N: content 20%) by sputtering under the following conditions A positively inclined semitransparent film (second semitransparent film) having a desired pattern was obtained by the same method as the formation of the flat translucent film in Example 1.
In the short-wavelength cut translucent film, a region where no resist pattern was formed was not etched by the etching solution used for etching the positively inclined semitransparent film forming layer.

<Film formation conditions>
Gas flow ratio Ar: CO ₂ : N ₂ = 2: 1: 1
・ Power: 1.3kW
・ Gas pressure: 3.5mTorr
The thickness of the positively inclined semitransparent film forming layer was 16 nm.

  As a result, a gradation mask having the first semi-transparent film (short wavelength cut semi-transparent film) and the second semi-transparent film (positive gradient semi-transparent film) as shown in FIG. 1 was obtained.

  In the obtained gradation mask, the transmittance of the i-line (365 nm) of the first translucent film (short wavelength cut translucent film) is 15%, and the second translucent film (positive gradient translucent film). The transmittance of i-line (365 nm) was 50%.

2. Production of color filter using gradation mask In the same manner as in Example 1, a color filter having three types of convex patterns on a transparent electrode was produced.

[Evaluation]
The cross-sectional shape of the convex pattern formed on the transparent electrode using the gradation mask of Example 1 and the gradation mask of Example 2 was observed with a scanning electron microscope. The evaluation results are shown in Table 1 below.

From Table 1, by using the gradation mask of Example 1 for the exposure process, on the transparent electrode, a columnar spacer having a columnar section, an auxiliary spacer having a cross-sectional shape (semicircular shape with a smooth top), and a flat surface A film-like overcoat layer could be formed at once.
Further, from Example 2, a columnar spacer having a high height and an auxiliary spacer having a low height could be formed on the transparent electrode. At the same time, a rice cake-shaped orientation control protrusion could be formed.
By using the gradation masks produced in Examples 1 and 2 in this way, patterns having different heights and shapes could be formed at once.

DESCRIPTION OF SYMBOLS 1 ... Transparent substrate 2 ... Light-shielding film 3 ... 1st semi-transparent film 4 ... 2nd semi-transparent film 10 ... Tone mask 11 ... Transmission region 12 ... Light-shielding region 13 ... 1st semi-transparent region 14 ... 2nd semi-transparent region 20 ... Layered body 22 ... Light shielding film forming layer 23 ... First semitransparent film forming layer 24 ... Second semitransparent film forming layer 25 ... Resist 30 ... Color filter forming substrate 34 ... Photosensitive resin layer 40 ... Color filter 41 ... 1st spacer 42 ... 2nd spacer 43 ... 3rd spacer 44 ... 1st orientation control protrusion 46 ... Overcoat layer

Claims (5)

A transparent substrate, a light shielding film formed directly on the transparent substrate and made of a light shielding film forming material, a first semitransparent film made of the first semitransparent film forming material and formed on the transparent substrate, and the transparent substrate A second translucent film formed on the second translucent film forming material,
A transparent region comprising the transparent substrate; a light shielding region including at least the transparent substrate and the light shielding film; a first semitransparent region comprising the transparent substrate and the first semitransparent film; the transparent substrate and the second semitransparent film. A gradation mask comprising a second translucent region made of a transparent film,
A gradation mask characterized in that the second translucent film forming material is different in resistance to an etching solution from the first translucent film forming material.   2. The gradation mask according to claim 1, wherein one of the first translucent film forming material and the second translucent film forming material is a chromium-based material and the other is a titanium-based material. The light shielding film forming material is the same kind of material as one of the first semitransparent film forming material and the second semitransparent film forming material,
The gradation mask according to claim 1, wherein the light shielding film is covered with at least one of the first semi-transparent film and the second semi-transparent film.   4. The gradation mask according to claim 1, wherein a spectral spectrum of the first semi-transparent film is different from a spectral spectrum of the second semi-transparent film. 5. A light-shielding film for forming a light-shielding film by etching the light-shielding film-forming layer of the laminate having a transparent substrate and a light-shielding film-forming layer formed of the light-shielding film-forming material on the transparent substrate in a pattern. A film forming step;
A first semitransparent film forming layer made of a first semitransparent film forming material is formed on the transparent substrate so as to cover the light shielding film, and then the first semitransparent film forming layer is etched into a pattern. A first translucent film forming step of forming a first translucent film directly formed on the transparent substrate,
A second semi-transparent film made of a second semi-transparent film forming material having a resistance to an etchant different from that of the first semi-transparent film forming material so as to cover the light shielding film and the first semi-transparent film on the transparent substrate. After forming the forming layer, the second semitransparent film forming layer is etched in a pattern with an etching solution for the second semitransparent film forming material, which is an etchant having resistance to the first semitransparent film forming material. A second translucent film forming step of forming a second translucent film directly formed on the transparent substrate,
A method for manufacturing a gradation mask, comprising:

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