JPS62276552A - Pattern forming mask and method for fabricating electronic device by using it - Google Patents

Abstract

PURPOSE:To obtain the desired thickness of an insulating film without increasing a number of manufacturing steps by forming a third part middle in light- transmittance between a first and a second parts in addition to the first part high in light transmittance and the second part having no light-transmittance. CONSTITUTION:The part 1 is the pattern of the substrate 11 perfectly coated with Cr and made dark or impossible to transmit light, the part 2 is the middle pattern of the substrate 11 coated with Cr in the form of meshes or stripes and enabled to transmit half of the light, and the white light part 3 is not coated with any Cr and it can transmit all the light. When a resist 4 is exposed to light through this film M, the resist film 4 is controlled in film thickness to form a resist pattern having a deep hole 7 and a middle step part 8, and when the insulating film 5 is etched through the resist pattern, a deep etched hole 9a and a shallow etched step 10 a little mild on the inside are formed in accordance with the film thickness of the resist pattern in a contact hole 9.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention is an iIJ for manufacturing electronic devices, particularly semiconductor devices.
It relates to mask (also called reticle) technology for forming resist patterns used in the lithography process.

[Prior art]

We have entered an era of miniaturization in which semiconductor processes form wiring widths of 0.5 μm to 1 μm, and therefore optical lithography techniques are diversifying.

In general lithography technology, a photosensitive resin film such as a resist formed on a substrate is irradiated with a source (ultraviolet rays or A film is formed on a semiconductor substrate.

The pattern of this photosensitive resin film is then used as an etching mask to form a semiconductor device.

The reticle is composed of a first portion having high light transmittance and a second portion having no light transmittance. The second part has a metal film such as chromium (Cr) as a barrier film on the main surface of a substrate such as transparent glass, and the first part has no barrier film formed thereon. It consists of a substrate such as transparent glass, and by forming a photoresist film in a desired pattern, a photosensitive resin film is selectively formed on the semiconductor substrate in accordance with the pattern.

The resist pattern selectively provided on the semiconductor substrate as described above is used, for example, as an etching mask.
The insulating film provided on the semiconductor substrate is selectively removed to form a contact hole or a through hole. The contact hole is a hole provided at the junction between the wiring and the semiconductor substrate, and the through hole is used to electrically connect the upper and lower wiring formed above and below the eyebrow insulation film in a multilayer wiring structure. This corresponds to the through hole formed in the glabellar insulating film.

On the other hand, in today's era of advances in miniaturization technology, for example, dry etching technology that allows microfabrication is increasingly used as an etching technology.

An example of the original Lingraphie technology is [-Integrated Circuit Engineering (I) J (Publication date: April 1979) published by Corona Co., Ltd.
May 5th) described on pages 78-83.

[Problem that the invention is trying to solve]

In the future miniaturization process of semiconductor devices, the above-mentioned dry etching technique will be absolutely necessary. but,
A feature of the dry etching method is that it is easy to perform anisotropic etching on a semiconductor substrate, and the etched side surface (end surface) is often vertical. In such a case, when attempting to provide a wiring layer by vapor-depositing A2 or the like on top of this, the coverage of l at the contact area or through-hole area is poor, causing disconnection at the edge area, resulting in problems such as disconnection defects. We are already beginning to see what will happen.

One solution to this problem is to form a non-steep opening (hole) by layering the photoresist and photo-etching multiple times. This was found to be undesirable due to the increase in the number of steps.

This invention was created after the inventors of the present invention considered modifying the mask itself in order to overcome the above-mentioned problems.

One object of the present invention is to provide a mask technique that can obtain a desired insulating film thickness without increasing the number of steps when processing an insulating film using a resist.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Failure to solve the problem]

A brief summary of typical inventions disclosed in this application is as follows.

In addition to the conventional first part with high light transmittance and the second part with no light transmittance, the pattern forming mask of the present invention has a new value between the light transmittance of the first part and the third part. The third portion has a light transmittance of .

This third portion is selectively provided between the first portion and the second portion, and is formed of 1× of the photosensitive resin film (resist).
The light transmittance of the photosensitive resin film is controlled at the beginning so that the thickness of the photosensitive resin film can be controlled.

The film thickness of the above photosensitive resin film is I! The larger the amount of light irradiated at the beginning, that is, the light intensity, the thicker the layer can be formed. This is because it depends on the degree of photochemical reaction of the photosensitive resin film.

The light transmittance of the third portion is controlled by forming a mesh-like or stripe-like pattern of a light-shielding film made of a metal film provided on a transparent substrate. Furthermore, accurate control of light transmittance is achieved by changing the mesh density or stripe spacing of the metal film as desired.

[Effect]

According to the above-mentioned means, since the light transmittance is controlled, the photosensitive resin film can be formed with a desired thickness. That is, when a contact hole or a through hole is formed, the thickness of the photosensitive resin film increases stepwise or continuously in the vicinity of the contact hole or through hole formation region as the distance from the center of the contact hole or the center of the through hole increases.
Ru. As a result, for example, when the etching ratio between the photosensitive resin film and the film to be etched (insulating film on the semiconductor substrate) cannot be maintained, the thickness of the photosensitive resin film is controlled as desired, so that the film to be etched can be etched. The amount of etching is inversely proportional to the thickness of the photosensitive resin film.

Therefore, the thinner part of the film to be etched and the thicker part (original film thickness) of the film to be etched are formed in sequence as the distance from the center of the original contact hole or through hole forming area increases. Become. As a result, the level difference near the contact hole or through hole is reduced, step coverage of other films formed on the film to be etched is improved, cut-offs can be prevented, and the yield of electronic devices is improved.

In addition, when using an insulating film as a mask for impurity introduction as a film to be etched, the depth of ion implantation into the semiconductor substrate can be determined by the film thickness of the mask in impurity introduction technology using ion implantation technology. Since it is possible to form an impurity introduction mask with a desired film thickness, the depth and concentration of the impurity introduction layer can be controlled as desired, and device characteristics can be improved.

The film thickness control of the film to be etched and the film thickness of the mask for impurity introduction described above can be easily performed by simply changing the mask for patterning the photosensitive m-lipid film. The above objectives can be achieved.

〔Example〕

1 and 2 show an embodiment of the present invention, and FIG. 1 shows an insulating film (or resist) having a stepped film thickness along the x-x' line direction in the figure. FIG. 2 is a plan view of the pattern of the pattern forming mask M used for forming the pattern, and FIG. 2 is a sectional view taken along the X-axis in FIG.

11 is a transparent substrate made of quartz glass, 1 and 2 are light shielding film patterns made of a metal film in which Cr is selectively formed on the main surface of the transparent substrate 11, and the hunting lines in FIG. 1 intersect at 6°. 1" is a dark pattern (originally non-transparent) as a second part in which Cr is formed on the entire surface of the substrate 11. In the part 2 where the notching is only on one side, Cr is formed in a mesh shape (or stripe shape). This is the middle part (originally semi-transparent) pattern as the third part formed, and the white part 3
is the bright part (originally completely transmitted) as the first part where Cr is completely absent.The light transmittance of this third part is controlled to a value between the light transmittance of the first part and the second part. be done.

FIG. 3 is a curve diagram corresponding to FIG. 2 and showing the light intensity distribution when the above-mentioned mask MK light is transmitted.

FIG. 4 is a sectional view showing a mode in which a resist as a photosensitive resin is exposed to light for forming a contact hole using the mask M. (This corresponds to the first step.) 4 is a resist film (positive type). 5 is an insulating film (film to be etched) to be drilled, and 6 is an underlying base #i (for example, a semiconductor substrate).

Through such a mask, light is exposed to 100% in bright areas, 50% in intermediate areas, and not exposed at all in dark areas.

FIG. 5 is a sectional view showing a state in which a photoresist pattern is formed by performing development after the above-mentioned exposure and dissolving and removing the exposed portion of the resist. (This corresponds to the second step.) As shown in the figure, the thickness of the resist film 4 is controlled in proportion to the original intensity during exposure. As a result, a resist pattern having deep hole portions 7 and middle portions 8 is formed. 6 is a sectional view showing a state in which the insulating film 6 is etched through the resist pattern to form a contact hole 9 as an opening.

As shown in the figure, a contact hole 9 is formed in the insulating film 6.
A deep hole 9a corresponding to the thickness of the resist pattern and a slightly gradual step 10 on the inner surface are formed. (This corresponds to the third step.) FIGS. 7 to 11 show modified examples of mask patterns.

FIG. 7 is a plan view of a mask pattern used to form the insulating film 5 having stepwise thicknesses along the X and Y directions.

In the figure, 1 is a dark pattern (second part) in which Cr is formed on the entire surface, and 2 is an intermediate pattern (second part) in which Cr is formed in a mesh shape.
3rd part), 3 is hole (contact hole or through hole)
Bright part of white cloth (transparent plate only) pattern corresponding to (first
part).

FIG. 8 is a modification of the mask pattern shown in FIG. 7, and is a mask pattern in which an intermediate pattern 2 is formed to surround a bright pattern 3.

FIG. 9 is a modification of the mask pattern shown in FIG. 1, in which the intermediate pattern 2 is provided only on one side of the bright pattern 3 which becomes the hole. The thickness change of the insulating film 5 is formed only on one side.

The mask patterns shown in Figures 1 and 9 can be used not only for contact holes but also for through-holes (see Figure 23) for connecting narrow wiring lines that intersect with each other. It is advantageous.

FIG. 10 shows a mask pattern having an intermediate pattern 2 along the X and Y directions of the bright pattern 3. 1st
FIG. 1 is a modification of the mask pattern shown in FIG. 10. The mask patterns shown in FIGS. 10 and 11 are suitable for providing a step part (or slope part) in an oblique direction (direction of arrow Z) with respect to the hole.

FIGS. 12 to 15 are enlarged plan views of the intermediate pattern (2) of the mask pattern shown in the above embodiment.

In the figure, the hunting part 16 is the Cr film part (second
), and the other parts correspond to the first part j
Ru.

FIG. 12 shows an example in which the Cr film 16 is arranged in a stripe pattern. By selecting the stripe spacing X, the light transmittance can be changed arbitrarily. For example, by changing the value of X within the range of 0.001 to o.o.s., an intermediate pattern with optimum light transmittance can be formed.

This striped pattern can be formed not only in the vertical direction but also in the horizontal direction, diagonal direction, etc.

FIG. 13 shows an example in which the cylindrical Cr films 16 are arranged alternately (in a checkered pattern). By appropriately selecting the width X of one mesh, mesh patterns from coarse to fine can be created.

FIG. 14 shows an example in which the Cr film 16 is arranged vertically and horizontally in a mottled manner, and FIG. 15 is a modification of FIG. 14 in which it is formed in a mottled white pattern. In either case, the width XI of the Cr film part + the width x2 of the white part is x, /x.

By choosing the value of , the light transmittance can be changed arbitrarily.

16 and 17 show other embodiments of the present invention, in which FIG. 16 is a cross-sectional view of a mask pattern used to form a hole having a tapered inner surface, and FIG. 17 is a cross-sectional view of the mask pattern described above. It is a curve diagram showing a light intensity distribution when light is transmitted through a mask.

In FIG. 16, 11 is a transparent substrate made of quartz glass, and 1 and 2 are glass surfaces 11 coated with Cr or the like. This is a pattern of the membrane.

Among these patterns, 1 is a dark pattern (second part) in which Cr is formed on the entire surface, 2 is a middle part pattern (third part) in which Cr is formed in a mesh or stripe shape, and 3 is a dark pattern (second part) in which Cr is formed on the entire surface. This is the bright part (third part) where there is no color.

The striped or mesh-like Cr of the intermediate pattern 2 is formed so that the stripe spacing or mesh density is controlled in a stepped manner so that it is denser on the dark pattern 1 side and coarser on the bright pattern 3 side. .

FIGS. 20 to 22 are enlarged plan views showing the intermediate pattern 2 and adjacent patterns.

Among these, in FIG. 20, the intermediate pattern 2 is formed in a stripe shape, and the stripe interval is on the bright side (2a
) is made thicker (and the dark side (2b) is made smaller).

FIG. 21 shows a mesh-like intermediate pattern 2.

FIG. 22 shows a mottled intermediate pattern 2.

The density of the Cr film as described above changes in density, and the light intensity distribution when light is transmitted through the patterned mask pattern in the middle part of the stone (2a to 2b) is as shown in the curve diagram in Figure 17. controlled by.

As shown in the figure, the light intensity of the j-stone portion corresponding to the intermediate pattern 2 has a stepwise or inclined curve from 10% to 30%.

FIG. 18 is a cross-sectional view showing a case where the mask is used to expose a resist to form a contact hole.

4 is a resist film (positive type), 5 is an insulating film, and 6 is a semiconductor substrate.

As shown in the figure, a resist pattern 4 having a thickness inversely proportional to the light intensity distribution is formed, and the taper angle θ of the resist pattern is accurately controlled.

FIG. 19 is a sectional view showing a state in which the insulating film 5 is dry-etched using the resist pattern described above.

As shown in the figure, the insulating film 5 is completely etched in the part corresponding to the bright part 3 of the mask, and becomes tapered in the part corresponding to the middle part 2, so that a contact hole 19 as shown in the figure is obtained. .

Next, a method for manufacturing an electronic device using the pattern forming mask of the present invention will be explained in more detail with reference to FIGS. 23 and 24. The example shown below is a detailed explanation between FIG. 5 and FIG. 6 described above.

First, the resist film 4 and the insulating film (
A case where the etching ratio with respect to SiOx film) 4 is sufficiently large will be explained.

In the first method, after the regimen film 4 is patterned as shown in FIG. Using an anisotropic dry etching technique such as RIE, the film 4 is etched to the middle of its thickness to form a cross section as shown in FIG. 23(A).

After that, a gas (O7
), only the resist film 4 is etched by RIE, and as shown in FIG. 23(B), the resist film 4 shown by the dotted line and the resist film 4 shown by the solid line are formed. Next, use Sin, a gas (CF4) that can only etch the film 5.
Alternatively, the 5ift film 5 is etched using CHF etching, and the 5iOz film 5 is processed to form an opening 52 as shown in FIG. 23(C). In this method, the etchant gas is This has the advantage that a Sin film 5 of a desired thickness can be obtained by only replacing the resist film 4, and the cross-sectional structure shown in FIG. 6 can be obtained by removing the resist film 4.

In the second method, after forming the cross-sectional structure shown in FIG. 5, resist film 4 and Sin! R using an etchant (O2) that can etch the film 5 at the same etching ratio.
Anisotropic etching was performed using the IE method and Fig. 23 CB
) to form a cross-sectional structure as shown in (). After that, S'+O
Using an etchant (CF or CHF) capable of etching only the T film 5, only the 5iOz film 5 is etched in the same RIE apparatus to form an opening 52 as shown in FIG. 23(C). After that, the resist film 4 is removed and the sixth
Obtain the structure of the diagram.

Note that 6 indicates a semiconductor substrate.

Next, FIG. 23 shows a manufacturing method when the etching mask 4 and the film to be etched 5 are made of the same material as the resist film 4 and the insulating film 5 (for example, polyimide resin, etc.) or when a large etching ratio cannot be obtained for some reason. This is shown using FIG. In this case, the etching ratio cannot be adjusted to a certain level, so
It should be noted that the resist film 4 and the insulating film 5 are etched away by the same amount.

After the resist film 4 is patterned as shown in FIG. 5, it is etched by RIE using an etchant (Ol) that can etch the resist film 4 and the insulating film 5 at the same etching ratio.
By etching the resist film 4 and the insulating film 5 in the same manner using a method, the opening 52 shown in FIG. 23(C) can be obtained. In this case, there is an advantage that the thickness of the insulating film 5 can be easily controlled by one-time etching removal. In this case, the thickness of the resist film 4 must be made sufficiently larger than the thickness of the insulating film 5.

FIG. 24 shows an example of the three-layer resist method in the above case.

The three-layer resist method uses a semiconductor substrate 6 (the upper layer includes a wiring layer)
An insulating film 5 such as a polyimide resin film having a flattening effect is formed on the substrate 6 by using a technique that reduces the height difference on the top and uses fine processing at the time of installation. A resist film 4 is formed on the inorganic film 50 and the Sin film 50.

In a normal three-layer resist process, the Si film 50 is etched using the resist 4 as an etching mask, and the insulating film 5 as a base film is etched by RIE using the etched SiQ film 5 as an etching mask. Insulating film 5
The width of the opening is Sin because it is created using an anisotropic RIE method.

It depends on the accuracy of the opening size of the film 50, and can be formed with extremely high precision compared to the wet etching method. Openings in the thin 5-inch film are performed using dry etching or wet etching, but due to the thin film thickness, the opening accuracy is extremely high (one of the advantages is that it is possible to do so. The problem is that it is necessary to form the insulating film 50 extremely thickly so that the surface of the insulating film 50 has a flattening effect. Therefore, the step of the opening formed in the insulating film 5 becomes high, and the surface of the insulating film 50 becomes very thick. However, it has the disadvantage that other films (for example, aluminum interconnection layers) may break off, resulting in defects.

On the other hand, in the three-layer resist method shown in FIG. is formed with a large width. As a result, step coverage at the stepped portion of another film (aluminum wiring layer) formed on the insulating film 5 is improved, and step breakage can be prevented. The three-layer resist method of the present invention will be explained using FIGS. 24(A), (B), (C), and (D).

FIG. 24(A) corresponds to the structure shown in FIG. 5, and shows a cross-sectional structure in which the thickness of the resist film 4 is controlled as desired. The difference from FIG. 5 is that the polyimide resin film 5 is thicker and there is a sinusoidal layer under the resist film 4.

The point is that a film-like inorganic film is formed.

The opening formed in this 5in2 film 50 can be formed with high opening accuracy by dry etching or wet etching. It should be noted that the etchant (gas, etching, tinting liquid) used is one that can etch only the 5iOr film 50 (0 or HF liquid).

Next, as shown in FIG. 24(B), the resist film 4
Etching is performed by the RIE method using an etchant (0 gas) that can simultaneously etch the polyimide film 5 and the polyimide film 5. At this time, the resist film 4 changes from the one shown by the dotted line to the one shown by the solid line, and a groove 51 having a depth corresponding to the change in film thickness is formed in the polyimide resin film 5. Incidentally, the Sin film 50 serves as an etching mask for the polyimide film 5 at this time.

Next, as shown in FIG. 24(C), the S film 02 film 50 is etched using the resist film 4 as an etching mask. For example, using the RIE method, Sin! This can be carried out using a gas (cF4.CHF) that can etch only the film 50. Of course, wet etching may also be used. Next, resist film 4 and polyimide film 5
The resist film 4 and the polyimide resin film 5 are simultaneously etched using an RIE method using an etching gas (0,) that can simultaneously etch the resist film 4 and the polyimide resin film 5 to form an opening 52 as shown in FIG. 24(D). .

The opening 52 consists of a narrow part 53 and a wide part 54, and the above-described drawbacks of the conventional three-layer resist method are improved, and step coverage of the aluminum wiring formed on the polyimide resin film 5 is improved. will improve. In other words, the wider the opening, the better the step coverage.

An opening is provided in the insulating film 5 by 5Kt as described above.

This opening 52 is preferably applied to a contact hole or a through hole. Next, its application will be explained.

FIG. 25 is a plan view when the present invention is applied to the opening of a through hole in a two-layer arrangement 520.21 that intersects at the top and bottom.

FIG. 26 is a sectional view taken along the line XX' in FIG. 25, and FIG. 25 is a sectional view taken along the <YY' line in FIG.

20 is a first layer Affl wiring, 21 is an interlayer insulating film, 22 is a second layer Aff wiring, and 23 is a through hole portion.

Reference numeral 55 indicates a contact portion between the upper and lower wirings.

In this case, using the mask patterns shown in FIGS. 1 and 2, the mask patterns shown in FIGS. By forming the through hole 23 having long (and stepped) side surfaces in the wiring direction (Y direction), it is possible to obtain a distribution connection portion with a small contact area and good coverage.

FIGS. 28 to 29 show examples in which the mask pattern according to the present invention is used to form a manoshell-shaped electrode 24 as a gate electrode of a GaAsFET. That is, using the mask pattern shown in FIG. 1 or FIG. 2, the resist 25 is formed in a stepped shape. (Fig. 28), and then remove the resist to obtain a pine mushroom-shaped gate electrode 24 (Fig. 29).
figure).

In addition, the source/drain regions of S, D+tGaAsFETs in FIGS. 28 and 29 are shown, and the GaAs substrate (G
This is an N-type impurity-introduced layer formed in (aAsub). This gate electrode structure has a short gate length, and the upper layer of the gate electrode is formed wide, so it is possible to reduce the contact resistance between the gate electrode and other metal wiring. It can be measured.

FIGS. 30 and 31 show that the film 27, etc., are etched using the pattern forming mask of the present invention.
This shows an example of a manufacturing method in which the film 27 is used as a mask for impurity introduction.

FIG. 30 shows the formation of an n-channel MO8) transistor. The feature of the manufacturing method is that a one-time impurity introduction step of impurity ions (for example, arsenic As) is used to introduce impurities into the drain D region (VA 30) into the low concentration region 31.
A high concentration area is formed with
The advantage is that 30 highly impurity-introduced layers can be formed at the same time. A structural feature is that there is a low concentration region 31 that increases the device breakdown voltage only in the drain D region, but not in the source S region, and it is possible to reduce the source resistance of the device.

This is because the implantation depth of impurity ions is inversely proportional to the thickness of the Sin film 27 as a mask for impurity introduction, and the thickness of the stepped portion 28 of the Sin film 27 is
This is possible because the thickness is smaller than that of the 5iOz film 27 other than 8iOz. Note that G indicates a polysilicon gate electrode of an N-channel M○S transistor, and 33 indicates a P-type impurity region.

FIG. 31 shows the state of formation of an impurity-introduced layer 30 that becomes a channel layer of a GaAsFET. The manufacturing method is characterized by using Sin as a mask for impurity introduction, forming an inclined portion 29 on the film 27 as shown in the figure, and transferring impurity ions such as silicon 81 to the substrate (GaAs) in one impurity introduction step.
sub ) 33 to form an impurity-introduced layer 30 as a channel layer having different depths. This principle is similar to that shown in the explanation of FIG. The structural feature is that the depth of the chamfer layer 30 is shallow on the drain D side;
This is a deep matter on the source S side. Therefore, the depletion layer extending from the channel layer to the drain D side can be easily extended to improve breakdown voltage, and the source resistance on the source S side can be reduced, improving the device characteristics of the GaAsFET.

μAbove, the invention made by the present inventor has been specifically explained based on examples, but the present invention is not limited to the above-mentioned examples and is not limited to the above examples, and it is understood that various changes can be made without departing from the gist of the invention. Needless to say.

The present invention can be used for general mask patterns of semiconductor devices using beam lithography.

〔effect〕

A brief explanation of the effects obtained by typical inventions disclosed in this application is as follows.

The light transmittance of the pattern-forming mask for the exposure agent of the photosensitive resin film is controlled by changing the light-shielding film pattern of the pattern-forming mask, and the amount of light (or light intensity) irradiated onto the resist film is controlled. Control. Therefore, since the photochemical reaction of the photosensitive resin film that depends on the element t (or light intensity) can be controlled, the film thickness and cross-sectional shape of the photosensitive resin film after the phenomenon can be controlled.

As a result, by using this photosensitive resin film, it is possible to control the shape, impurity concentration distribution, and impurity-introduced layer depth of contact hole portions and through-hole portions, and the yield of electronic devices is increased by JPt! ! Improve your f-ability.

For example, in contact portions and through-hole portions, the cross-sectional shape of the film to be etched can be controlled by controlling the thickness of the photosensitive resin film, thereby controlling the step shape of those portions. As a result, the width of the opening (hole) in the etched film in the contact hole area or through hole area can be made wider on the upper side and narrower on the lower side. The step coverage is the same as above, cutting can be prevented, and the manufacturing yield of electronic devices is improved.

Furthermore, since the above-mentioned effects can be obtained only by changing the pattern of the pattern-forming mask, changes in the miniaturization process and reduction in the degree of integration can be prevented.

[Brief explanation of drawings]

1 to 3 show an embodiment of a pattern forming mask according to the present invention, in which FIG. 1 is a plan (bottom) view, and FIG. 2 is a cross-sectional view along the X line in FIG. 1. , Figure 3 is the second
4 to 6 are process cross-sectional views showing the form of forming openings (holes) using the mask of FIG. 1 (FIG. 2), and FIG. 11 to 11 are plan (bottom) views showing modified examples of the mask shown in FIG. 1, FIGS. 12 to 15 are enlarged views of the third portion (middle portion) in FIG. FIG. 17 shows another embodiment of the present invention,
Of these, Fig. 16 is a cross-sectional view of the mask, and Fig. 17 is a cross-sectional view of the mask.
FIGS. 18 to 19 are process cross-sectional views showing the form of forming openings (holes) using the mask shown in FIG. 16, and FIGS. Figure 22 is an enlarged view of a part of Figure 16, and Figures 23 (A), 23 (B), and 23 (C) are further details of the manufacturing process shown in Figures 5 and 6. Detailed process cross-sectional views, FIGS. 24(A), 24(B), 24(C), and 24(D) are shown in FIGS. 5 and 6. 25 is a plan view of a multilayer wiring showing another embodiment of the present invention; FIG. 26 is a sectional view taken along line x-x' in FIG. 25;
The figure is a sectional view taken along line 4YY', and FIGS. 28 to 31 are sectional views showing examples of workpieces using the mask according to the present invention. 11...Glass substrate, 1...Cr pattern (dark area)
, 2...Cr pattern (middle part), 3...Bright part, 4
... Photoresist film, 5... Insulating film, 6... Housing. Agent Patent Attorney Katsuo Ogawa Fig. 1 Fig. 3 Fig. 7-1 Fig. 4 Fig. 5 Fig. 6 Fig. Figure 22 Figure 23 (A) Figure 23 (C') δJ Figure 24 (AI Figure 24 (E) Figure 24 (C) Figure 24 CD)

Claims (1)

[Claims] 1. A first part with high light transmittance, a second part with no light transmittance, and light having a value between the light transmittance of the first part and the light transmittance of the second part. A pattern forming mask, comprising: a third portion having transmittance. 2. The pattern forming mask according to claim 1, wherein the third portion is provided in a desired area between the first portion and the second portion. 3. The second part is composed of a light shielding film made of a metal film provided on the main surface of a transparent substrate, and the first part is composed of the transparent substrate without the light shielding film, The third portion is formed by a combination of the first portion and the second portion in which the light-resistant film is selectively provided on the transparent substrate, and as a result, the light transmittance of the third portion is as high as the light transmittance. 3. The pattern forming mask according to claim 2, wherein the pattern forming mask is controlled between that of the first portion and that of the second portion. 4. The pattern forming mask according to claim 2, wherein the pattern of the light shielding film provided in the third portion is made of a metal film formed in a mesh shape or a stripe shape. 5. Controlling the light transmittance of the third portion by changing the density of the metal film of the third portion stepwise or continuously on the path from the first portion to the second portion. The pattern forming mask according to claim 4, characterized in that: 6. The pattern forming mask according to claim 4, wherein the density of the metal film is determined by changing the mesh density or the stripe spacing. 7. The third part is surrounded by the second part,
2. The pattern forming mask according to claim 1, wherein the light transmittance of the third portion changes in a stepwise or inclined manner from one side of the third portion to the other side. 8. A first step of forming a photosensitive resin film on an insulating film provided on one main surface of a semiconductor substrate, a first portion with high light transmittance, a second portion with no light transmission, and the first portion. After irradiating the photosensitive resin film with light through a pattern forming mask comprising a third portion having a light transmittance between the light transmittance and the light transmittance of the second portion, a second step of selectively forming the photosensitive resin film with a controlled film thickness on the insulating film; and using the selectively provided photosensitive resin film as an etching mask to form a desired pattern. A method of manufacturing an electronic device, comprising: a third step of forming an insulating film.