JP2005308901A - Pellicle frame and pellicle for photo lithography using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pellicle frame which can avoid damages to the pellicle film and the adhesive layer and particles generated and can be uniformly pressurized to an exposure original. <P>SOLUTION: This is a frame of the pellicle for photo lithography having upper and lower end surfaces to stick a pellicle film and whose lower surface is stuck to an exposing original plate. A groove 2, a protrusion or a level difference is formed partly or all around the upper end surface of this frame. An area 3 is secured inner than the groove, protrusion, and the level difference to stick a pellicle film through an adhesive layer. Further, an area 4 is provided at the outside of the groove, protrusion and level difference to pressurize the pellicle frame 1 to the exposing original plate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pellicle frame that is affixed to an exposure original plate as dust protection when manufacturing a liquid crystal display panel or the like, and more particularly to a large pellicle frame having a side of 30 cm or more.

Conventionally, as one of the manufacturing processes of a liquid crystal display panel, there is a photolithography process in which patterning is performed by irradiating an original with light. In the manufacture of liquid crystal display panels, which have been remarkably advanced in recent years, as the size of liquid crystal masters has increased, the degree of pattern integration has also increased.
If dust such as particles adheres to the exposure original plate used in the photolithography process, the particles absorb light or bend the light, so that the particles are transferred, the pattern is deformed, or the edges are scratched. In addition to this, the size, quality, appearance, etc. are impaired such that the white background is blackened and the liquid crystal display panel performance and manufacturing yield are lowered.

  Although operations related to the photolithography process are usually performed in a clean room, it is difficult to always keep the exposure original plate clean even in the clean room. Therefore, in order to avoid adhesion of particles to the surface of the exposure original plate, exposure is performed by attaching a pellicle to the exposure original plate.

In general, the pellicle is made of, for example, nitrocellulose, cellulose acetate, or the like that allows exposure light to pass through the upper end surface 32 of a rectangular pellicle frame 31 made of aluminum, stainless steel, iron, or other metal as shown in FIG. A transparent film (pellicle film) made of an amorphous fluorine-based resin or the like can be obtained by bonding with an adhesive such as an acrylic resin or an epoxy resin (see Patent Document 1 and Patent Document 2).
Further, an adhesive layer made of a styrene-ethylene-butadiene-styrene resin, a polyvinyl acetate resin, an acrylic resin, a silicone resin, or the like is provided on the lower end surface 33 of the frame 31 to be attached to the exposure original plate. A separator for the purpose of protecting the adhesive layer is provided.

  When the pellicle is attached to the exposure original plate, the separator is peeled off and attached to a predetermined position of the exposure original plate. As a result, the particles do not directly adhere to the surface of the exposure original plate but adhere to the pellicle film. Therefore, if the focus is set on the pattern of the exposure original plate during lithography, it is possible to prevent the particles attached to the pellicle film from being transferred.

  The pellicle used for the mask master for photolithography used in the manufacturing process of the liquid crystal display panel in recent years is a large pellicle with one side of the frame of 30 cm or more as the size of the master increases. Some are over 1m. When affixing such a large pellicle to the exposure original plate, for example, after the separator is peeled off and placed at a predetermined position on the exposure original plate, the outer periphery of the upper end surface of the pellicle frame can be pressurized. Set the tool and pressurize the exposure master through a jig. An apparatus for attaching a large pellicle to an exposure original plate has also been developed (for example, trade name “M515L” manufactured by Matsushita Seiki Co., Ltd.).

However, if a large load is applied to the upper end surface of the pellicle frame in order to securely attach the pellicle to the exposure original plate, there are problems that the pellicle film and the adhesive layer are damaged and particles are easily generated.
Further, as the size of the pellicle increases, it becomes more difficult to press the entire pellicle uniformly on the exposure original plate, which makes it difficult to attach the pellicle to the exposure original plate with high accuracy.

US Pat. No. 4,861,402 Japanese Patent Publication No. 63-27707

  The present invention has been made in view of the above problems, and can effectively prevent damage to the pellicle film and the adhesive layer and generation of particles, and can uniformly pressurize the exposure original plate. The main purpose is to provide a frame.

  In order to achieve the above object, according to the present invention, there is provided a pellicle frame for a photolithography pellicle having an upper end surface and a lower end surface, a pellicle film attached to the upper end surface, and a lower end surface attached to an exposure original plate, Grooves, protrusions, or steps are formed on the entire upper surface or part of the upper end surface of the frame, and an area for attaching a pellicle film via an adhesive layer is formed inside the grooves, protrusions, or steps. A pellicle frame is provided, wherein a region for pressing the frame against the exposure original plate is provided outside the groove, protrusion, or step. 1).

In this way, if a pellicle frame is formed in two regions by forming grooves, protrusions, or steps on the upper end surface, an adhesive layer can be provided only in a region inside the grooves and the pellicle film can be attached. .
In addition, when the frame having the pellicle film attached thereto is attached to the exposure original plate as described above, the outer region is uniformly applied without applying pressure to the inner adhesive layer from the groove or the like, and is securely attached. In addition, damage to the adhesive layer and generation of particles can be reliably prevented.

The pellicle frame may have a rectangular shape with at least one side of 30 cm or more.
A pellicle having such a large pellicle frame requires a particularly large load when being attached to the exposure original plate. However, if a groove or the like is formed on the upper end surface as in the present invention, the top of the pellicle frame It becomes possible to pressurize the outer part of the end face selectively and accurately, which is particularly effective.

The depth of the groove is preferably 50 μm or more.
If the groove having the above depth is formed on the upper end surface of the frame, when the adhesive layer is formed, it is possible to more reliably prevent the adhesive from flowing out with the groove as a boundary.

Preferably, the height of the protrusion is 1 mm or less (Claim 4), and the step is also 1 mm or less (Claim 5).
If the size of the protrusion or step on the upper end surface of the frame is 1 mm or less, it is possible to reliably prevent the possibility of trouble during handling and exposure.

  Further, according to the present invention, there is provided a pellicle for photolithography, comprising at least a pellicle frame, an adhesive layer provided on an upper end surface of the frame, and a pellicle film attached to the frame via the adhesive layer. And the frame is a pellicle frame according to the present invention, wherein an adhesive layer is provided on an upper end surface inside the groove, protrusion, or step, and the pellicle film is interposed through the adhesive layer. A pellicle for photolithography, which is affixed, is provided (claim 6).

  As described above, when the pellicle using the pellicle frame according to the present invention is used, only the outer region where the upper end surface is exposed is applied without applying pressure to the adhesive layer provided on the inner side of the groove or the like when the pellicle is attached to the exposure original plate. Can be applied uniformly to the exposure original plate. Therefore, even a particularly large pellicle can be adhered to the exposure original plate while preventing damage to the adhesive layer and generation of particles.

  If the pellicle frame has grooves, protrusions, or steps formed at predetermined positions on the upper end surface according to the present invention, the adhesive layer can be formed by applying an adhesive only inside the grooves. In addition, when pasting on the exposure substrate, the area outside the groove or the like on the upper end surface of the frame can be strongly pressed without damaging the pellicle film or adhesive layer, and the pellicle can be affixed to the exposure original plate with high accuracy and uniformity. I can.

Hereinafter, a pellicle frame and a pellicle according to the present invention will be specifically described with reference to the accompanying drawings.
Prior to the completion of the present invention, the present inventors have been able to properly control the width of the adhesive layer for attaching the pellicle film to the pellicle frame, Study was carried out. As a result, by providing a predetermined structure on the upper end surface of the pellicle frame, that is, a groove, a protrusion, or a step, not only the adhesive application area is reduced, but also the spread of the liquid adhesive due to surface tension or the like is suppressed. The present inventors have found that an adhesive layer can be formed only in a region inside a groove or the like. Also, if the pellicle frame is provided with a groove or the like on the upper end surface in this way, after the pellicle film is attached to form a pellicle, the inner adhesive layer is pressurized by pressing the area outside the groove or the like. Thus, the present invention has been completed by finding that it can be uniformly applied to the exposure original plate.

1A and 1B show an example of a pellicle frame according to the present invention. The pellicle frame 1 has one groove 2 formed over the entire circumference of the upper end surface. Inside the groove 2 is a region 3 for attaching a pellicle film via an adhesive layer, and outside the groove 2 is a region 4 for pressing the frame 1 against the exposure original plate.
That is, if the groove 2 as shown in FIG. 1 is formed on the upper end surface of the frame 1, the liquid adhesive can be accurately applied to the inner region 3, and the surface tension at the boundary portion of the groove 2, etc. Outflow and spread of the adhesive to the outer region 4 can be prevented. Accordingly, it is possible to easily form an adhesive layer only in the region 3 inside the groove 2 and to attach the pellicle film via this adhesive layer.

  On the other hand, the adhesive layer is not formed in the region 4 outside the groove 2, and the surface of the frame 1 is exposed. In particular, when a large pellicle with one side of the frame 1 of 30 cm or more is used, it is necessary to apply high pressure to the upper end surface of the frame 1 when being attached to an exposure original plate (reticle). The end face can be uniformly pressed by an attaching jig or the like, and can be attached to the original plate with high accuracy and reliability.

Further, when a large pellicle is attached to the exposure original plate, the pellicle is required to have a very high flatness, but the upper end surface of the pellicle frame 1 is directly and uniformly pressed without using an adhesive layer or a pellicle film. Therefore, the pellicle after pasting has a very high flatness.
And like the case where the adhesive layer etc. are pressurized, the trace and damage | wound of a jig | tool are hard to remain, and generation | occurrence | production of a particle can be prevented effectively.

In addition, when the pellicle is stored in a case during transportation and storage, it can be stored in a state where the outside of the upper surface where the frame 1 is exposed is strongly pressed, and the outer peripheral portion can be gripped when handling the pellicle. Generation of particles can be effectively suppressed without causing marks or scratches on the pellicle film or the like.
Furthermore, since the adhesive layer can be formed only on the inner side of the upper end surface of the pellicle frame 1, there is an effect of minimizing outgas generated from the adhesive.

The cross-sectional shape of the groove 2 is not limited to a triangle as shown in FIG. 1B, but may be a shape having an effect similar to this, for example, a quadrangle, a semicircle, or a semi-ellipse.
The depth and width of the groove 2 may be appropriately determined depending on the size of the pellicle frame, the viscosity of the adhesive, and the like. However, if the groove 2 is too shallow, the effect of stopping the adhesive due to surface tension may not be sufficiently obtained. The depth of 2 is preferably 50 μm or more. The width of the groove 2 is preferably 50 μm or more for the same reason.

  Although the position of the groove 2 depends on the width (thickness) t of the frame 1 and the like, if the region 3 inside the groove 2 is too narrow, it becomes difficult to attach the pellicle film. On the other hand, when the region 4 outside the groove 2 is too narrow, it is difficult to pressurize the exposure original plate. From these viewpoints, it is preferable to form the grooves 2 so that the widths of the regions 3 and 4 are 1 mm or more.

  The material of the frame 1 is not particularly limited as long as it is used as a pellicle frame, and aluminum alloy, stainless steel, stainless steel, or the like can be used.

  FIG. 2 shows another example of the pellicle frame according to the present invention. The pellicle frame 11 has a continuous projection 12 formed over the entire circumference of the upper end surface. Inside the projection 12 is an area 13 for attaching a pellicle film via an adhesive layer, and outside the projection 12 is an area 14 for pressing the frame 11 against the exposure original plate.

Thus, in the case of the pellicle frame 11 in which the protrusion 12 is formed on the upper end surface of the frame 11, it is further effective that the adhesive applied to the region 13 inside the protrusion 12 flows out to the region 14 outside the protrusion 12. The adhesive layer can be formed only on the inner region 13.
The cross-sectional shape of the projection 12 is not limited to a triangle like the groove 2, but can have a shape having the same effect as that of the groove 2, for example, a cross-sectional shape such as a quadrangle, a semi-circle, and a semi-ellipse. .
In addition, if the protrusion 12 is made higher than necessary, there is a possibility that trouble may occur during handling or lithography. Therefore, the height of the protrusion 12 is preferably 1.0 mm or less. However, in order to reliably prevent the adhesive from flowing out, the height of the protrusion 12 is preferably 0.1 mm or more.

  FIG. 3 shows still another example of the pellicle frame according to the present invention. The pellicle frame 21 has a continuous step 22 over the entire circumference of the upper end surface. Inside the step 22 is an area 23 for attaching a pellicle film via an adhesive layer, and outside the step 22 is an area 24 for pressing the frame 21 against the exposure original plate.

In this case, the same effect as that obtained when the grooves 2 and the protrusions 12 are formed can be obtained. In addition, if the level difference 22 on the upper end surface is made larger than necessary, it may cause troubles in handling and lithography. Therefore, it is preferably set to 1.0 mm or less, and also prevents the adhesive from flowing out. , 0.1 mm or more is preferable.
The step on the upper end surface of the frame is not limited to a shape in which the inside of the frame 21 is higher than the outside as shown in FIG. It may be a step with an inclination.

FIG. 4 schematically shows a pellicle 26 formed by attaching the pellicle film 7 to the pellicle frame 21 shown in FIG.
An adhesive layer 5 is formed by applying an adhesive to a region 23 inside the step 22 on the upper end surface of the frame 21, and an adhesive layer 6 is provided on the lower end surface 25 of the frame 21 to be attached to the exposure original plate. Yes. Then, the pellicle 26 can be formed by attaching the pellicle film 7 via the adhesive layer 5 on the upper end surface.

  With such a pellicle 26, the exposure original plate is placed at a predetermined position, and a region 24 outside the upper end surface where the adhesive layer 5 is not formed is uniformly pressed against the exposure original plate with a jig or the like. And can be accurately and reliably affixed to the original.

Examples of the present invention and comparative examples will be described below.
(Example 1)
As the pellicle frame, the height is 5.5 mm, the long side length is 782.0 mm, the short side length is 474.0 mm, the long side thickness (width) is 9.0 mm, and the short side thickness (width) is 7. A frame made of an aluminum alloy having an anodized surface of 0 mm is prepared, and the groove as shown in FIG. 1 has a groove center of 3 mm from the inner edge over the entire periphery of the upper end surface, and a width of 0. It was formed to have a depth of 5 mm and a depth of 0.3 mm.
A 15% toluene solution of silicone adhesive KR-3700 (manufactured by Shin-Etsu Chemical Co., Ltd.) is used as an adhesive in the inner region partitioned by the groove 2 on the upper end surface of the pellicle frame, and has a needle having an inner diameter of 0.3 mm. It applied so that the thickness might be 0.2 mm and the surface might become smooth using a dispenser.

  On the other hand, after applying a silicone-based pressure-sensitive adhesive as a pressure-sensitive adhesive to the lower end surface of the frame, the frame was heated at 120 ° C. for 30 minutes to cure the adhesive and pressure-sensitive adhesive. When the upper end surface of the pellicle frame to which the adhesive was applied was observed after the heating was completed, the adhesive layer was formed almost uniformly with a maximum width of about 2.8 mm along the edge of the groove from the inside over the entire periphery of the frame.

Next, a thin film of Cytop CTX-S type (manufactured by Asahi Glass Co., Ltd.) having a thickness of 4.0 μm was prepared as a pellicle film, and pasted through an adhesive layer previously formed on the upper end surface of the pellicle frame.
The pellicle thus obtained was placed at a predetermined position on the exposure original plate, and a sticking jig capable of pressing the outer peripheral portion of the upper end surface of the pellicle frame with a width of 2 mm was set. Then, a pellicle frame was attached to the exposure original plate with a weight of 30 kg for 3 minutes using an attaching jig.
When the pellicle affixed to the exposure original plate as described above was held together with the light projector with the projector, and the upper end surface of the pellicle film and the pellicle frame was observed, no particles were found. Further, no defects such as scratches were found on the adhesive layer and the pellicle film.

(Example 2)
A frame made of an aluminum alloy having the same size as the frame used in Example 1 and anodized on the surface is prepared, and a protrusion as shown in FIG. 2 having a width of 0.5 mm and a height of 0.3 mm is 3 mm from the inside. Formed.
In the same manner as in Example 1, a silicone adhesive was applied to the inner region partitioned by the protrusions on the upper end surface of the pellicle frame.
On the other hand, after applying a silicone-based pressure-sensitive adhesive to the lower end surface of the frame, the adhesive and the pressure-sensitive adhesive were cured by heating at 120 ° C. for 30 minutes.
When the upper end surface of the pellicle frame to which the adhesive was applied was observed after the heating, the adhesive layer was almost uniformly formed with a maximum width of 2.7 mm along the protrusions from the inside over the entire periphery of the frame.

Next, a thin film of Cytop CTX-S type (manufactured by Asahi Glass Co., Ltd.) having a thickness of 4.0 μm was prepared as a pellicle film, and pasted through an adhesive layer previously formed on the upper end surface of the pellicle frame.
The pellicle thus obtained was placed at a predetermined location on the exposure original plate, and the attaching jig used in Example 1 was set and attached to the exposure original plate.
Observation of the pellicle film of the pellicle and the upper end surface of the pellicle frame attached to the exposure original plate in this way showed no particles or defects.

(Example 3)
A frame made of an aluminum alloy having the same size as the frame used in Example 1 and anodized on the surface is prepared, and the height is 0.3 mm and the inclination is 45 mm so that the inner side is higher than the outer side at 3 mm from the inner side. A pellicle frame with a step difference of ° was produced.
A silicone adhesive was applied to an inner region partitioned by a step on the upper end surface of the frame in the same manner as in Example 1, and a silicone adhesive was applied to the lower end surface of the frame. And it heated at 120 degreeC for 30 minute (s), and the adhesive agent and the adhesive were cured.
When the upper end surface of the pellicle frame to which the adhesive was applied was observed after the heating, the adhesive layer was almost uniformly formed with a maximum width of 2.9 mm along the step from the inside over the entire periphery of the frame.

Next, a thin film of Cytop CTX-S type (manufactured by Asahi Glass Co., Ltd.) having a thickness of 4.0 μm was attached as a pellicle film via an adhesive layer previously applied to the upper end surface of the pellicle frame.
The pellicle thus obtained was affixed to the exposure original plate in the same manner as in Example 1, and when the pellicle film and the upper end surface of the pellicle frame were observed, no particles or defects were observed.

(Comparative Example 1)
An aluminum alloy pellicle frame having the same size as in Example 1 and anodized on the surface was prepared, and the upper end surface was kept flat as shown in FIG.
A silicone adhesive was applied to the upper end surface of the frame in the same manner as in Example 1, and then a silicone-based adhesive was applied to the bottom surface of the frame, followed by heating at 120 ° C. for 30 minutes to cure the adhesive and the adhesive. .
When the upper end surface of the frame was observed after the heating, the adhesive layer was almost uniformly formed on the entire upper end surface over the entire periphery of the frame.

Next, a thin film of Cytop CTX-S type (manufactured by Asahi Glass Co., Ltd.) having a thickness of 4.0 μm was attached as a pellicle film via an adhesive layer previously provided on the upper end surface of the pellicle frame.
The pellicle thus obtained was placed at a predetermined position on the exposure original plate, and the pellicle frame was attached to the exposure original plate with a weight of 30 kg for 3 minutes using the attaching jig used in Example 1.

  The pellicle was held together with the exposure original plate with a projector, and the pellicle film and the like were observed. As a result, traces deformed by pressurization remained in the portion pressed by the sticking jig. In addition, a large number of particles were observed inside the adhesive layer that was not pressed by the sticking jig, and five particles that were thought to be generated when the sticking jig was pressed were also observed near the frame of the pellicle film. It was.

  The present invention is not limited to the above embodiment. The above embodiment is merely an example, and the present invention has the same configuration as that of 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.

For example, in the above-described embodiment, a description has been given of a case where grooves, protrusions, or steps are provided on the entire periphery of the frame. However, the grooves or the like may be provided in a part of the frame such as intermittently formed on the upper end surface. .
The pellicle frame according to the present invention can also be suitably used for a pellicle for photolithography, for example, in the manufacture of semiconductor devices.

It is the schematic which shows an example of the pellicle frame which concerns on this invention. (A) Plan view, (B) Cross section It is the schematic which shows another example of the pellicle frame which concerns on this invention. (A) Plan view, (B) Cross section It is the schematic which shows another example of the pellicle frame which concerns on this invention. (A) Plan view, (B) Cross section FIG. 4 is a schematic cross-sectional view showing a pellicle film attached to the pellicle frame of FIG. 3. It is the schematic which shows a general pellicle frame. (A) Plan view, (B) Cross section

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,11,21 ... Pellicle frame, 2 ... Groove, 3, 13, 23 ... Area for attaching a pellicle, 4, 14, 24 ... Area for pressurizing a frame, 5 ... Adhesive layer, 6 ... Adhesive layer 7 ... Pellicle film, 12 ... Protrusion, 22 ... Step, 25 ... Lower end surface, 26 ... Pellicle.

Claims (6)

  A pellicle frame for a photolithography pellicle that has an upper end surface and a lower end surface, a pellicle film is attached to the upper end surface, and the lower end surface is attached to an exposure original plate. , A groove, a protrusion, or a step is formed, and an area for attaching a pellicle film via an adhesive layer is provided inside the groove, the protrusion, or the step, and the groove, the protrusion, or the step, A pellicle frame characterized in that a region for pressing the frame against the exposure original plate is provided on the outside.   The pellicle frame according to claim 1, wherein the pellicle frame is a rectangle having at least one side of 30 cm or more.   The pellicle for photolithography according to claim 1 or 2, wherein the depth of the groove is 50 µm or more.   The pellicle for photolithography according to claim 1 or 2, wherein the height of the protrusion is 1 mm or less.   The pellicle for photolithography according to claim 1 or 2, wherein the step is 1 mm or less.   A pellicle for photolithography, comprising at least a pellicle frame, an adhesive layer provided on an upper end surface of the frame, and a pellicle film attached to the frame through the adhesive layer, The pellicle frame according to any one of claims 1 to 5, wherein an adhesive layer is provided on an upper end surface inside the groove, protrusion, or step, and the pellicle is interposed through the adhesive layer. A pellicle for photolithography characterized by having a film attached thereto.

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