JP2006285122A - Method for making double-sided mask - Google Patents

Abstract

An object of the present invention is to provide a method for producing a double-sided mask provided with a protective layer for protecting a pattern formed on one surface of a transparent substrate in a method for producing a double-sided mask having patterns on both sides of a transparent substrate. And
A resist in which a main pattern is formed on one surface of a transparent substrate, a light shielding layer and a resist layer are formed on the other surface of the transparent substrate, and a pattern is drawn to form a pattern latent image. After forming the layer 32a, a protective layer 43 is formed on one surface of the transparent substrate 11, and the light shielding layer 22 on the other surface of the transparent substrate 11 is patterned to remove the protective layer 43. A double-sided mask 100 having a main pattern 21a on one side and a pattern 22a on the other side is produced.
[Selection] Figure 3

Description

  The present invention relates to a method for producing a double-sided mask having a pattern on both sides of a transparent substrate, and in particular, after forming a pattern on one side of a transparent substrate, a light shielding layer and a resist layer are formed on the other side of the transparent substrate. In addition, the present invention relates to a method for producing a double-sided mask in which a protective layer is provided on one surface of a transparent substrate after pattern drawing to produce a pattern on the other surface of the transparent substrate.

  As a method for producing a double-sided mask having patterns on both sides of a transparent substrate, a mask having front and back patterns is formed on each transparent substrate to produce two masks, and the two masks are positioned. There are a method of producing a double-sided mask by bonding the back surfaces together with a transparent adhesive, and a method of producing a double-sided mask by forming patterns on the front and back of a single transparent substrate.

However, in the method of making the double-sided mask by aligning the two masks and bonding the back surfaces together, the transparent substrate on which the pattern is formed is bonded, so it takes a lot of work, When pasting, air bubbles may enter between the transparent substrates, resulting in a defective product.
Furthermore, since it takes time and heat to completely cure the adhesive after alignment with the alignment jig, there is a problem that the transparent substrate is displaced and becomes defective.

In order to solve the above problem, a method of forming a double-sided mask by forming a pattern on both sides of a single transparent substrate has been proposed (see, for example, Patent Document 1).
This is an example of a double-sided pattern forming method for a double-sided mask used for producing a hologram.
5 (a) to 5 (e) and FIGS. 6 (f) to 6 (h) are schematic cross-sectional views showing an example of a conventional method for producing a double-sided mask.
First, as shown in FIG. 5A, a first resist layer 121 is formed on one surface of the transparent substrate 111.

  Next, the transparent substrate 111 with the first resist layer 121 formed on one surface is placed on a stage of a predetermined alignment apparatus, and the first resist layer 121 is pattern-exposed through a first photomask. Subsequently, development processing is performed to form a resist pattern 121a (see FIG. 5B).

Next, the transparent substrate 111 is etched to a predetermined depth using the resist pattern 121a as a mask (see FIG. 5C).
Next, the resist pattern 121a is removed by ashing, and an alignment mark 111a ′ and a pattern 111a are formed at predetermined positions on one surface of the transparent substrate 111 (see FIG. 5D).

Next, a second resist layer 122 is formed on the other surface of the transparent substrate 111 (see FIG. 5E).
Next, the transparent substrate 111 on which the second resist layer 122 is formed is placed on the stage of the alignment apparatus with the second resist layer 122 facing up, and the alignment mark of the second photomask and the transparent substrate 111 The alignment mark 111a ′ is aligned, and the second resist layer 122 is pattern-exposed through a second photomask. Subsequently, development processing is performed to form a resist pattern 122a (see FIG. 6F).

Next, the transparent substrate 111 is etched to a predetermined depth using the resist pattern 122a as a mask (see FIG. 6G).
Next, ashing is performed to remove the resist pattern 122a, and a pattern 111b is formed at a predetermined position on the other surface of the transparent substrate 111 to obtain a double-sided mask for producing a hologram (see FIG. 6 (h)).

  In this way, since the double-sided mask is made by forming patterns on both sides of the transparent substrate, the workability is improved compared to the conventional bonding method, but in the recent photomask field, the pattern has been miniaturized. Therefore, a double-sided mask corresponding to higher accuracy is required, and the patterning accuracy and pattern accuracy cannot be cleared by the bonding method.

In such a situation, after forming a pattern on one surface of the transparent substrate, a pattern is formed on the other surface of the transparent substrate. A method for manufacturing a mask is proposed.
Specifically, first, a light shielding layer made of chromium, a chromium oxide film or the like is formed on one surface of a transparent substrate, and further a resist layer is formed, and patterning processing such as pattern drawing and development is performed to form a resist pattern. Form.
Next, using the resist pattern as a mask, the light shielding layer is etched, and the resist pattern is peeled off to form a pattern.

  Next, a light-shielding layer made of chromium, a chromium oxide film, etc. is formed on the other surface of the transparent substrate having a pattern formed on one surface, and a series of patterning processes are performed to A pattern is formed on this surface to obtain a double-sided mask in which the pattern is formed on both sides of the transparent substrate.

  As a lithography technique for the manufacturing process of the double-sided mask, electron beam writing is used as a pattern writing method on a resist layer, dry etching and light etching are used as etching methods for a light shielding layer, in response to miniaturization and high accuracy of a photomask pattern. Wet etching uses plasma ashing or the like as a resist pattern removal method.

When applying electron beam drawing as a pattern drawing method on the resist layer, the processing substrate needs to maintain a predetermined degree of vacuum during electron beam drawing, and a material that lowers the degree of vacuum is used for the processing substrate. It becomes a problem.
In addition, when dry etching is performed as an etching method for the light shielding layer, there is a risk of damaging the transparent substrate under the light shielding layer. Have the problem of
In addition, if the light-shielding layer on the other surface of the transparent substrate is wet-etched with the pattern already formed on one surface of the transparent substrate, the pattern already formed on the one surface of the transparent substrate is damaged. Resulting in problems such as loss of pattern accuracy.

In addition, if a pattern is already formed on one side of the transparent substrate and plasma ashing is performed on the resist pattern on the other side of the transparent substrate, the pattern already formed on the one side of the transparent substrate is damaged. And the problem of deteriorating the pattern accuracy of one surface of the transparent substrate occurs.
JP-A-6-252023

Thus, in the manufacturing process of the double-sided mask, in order to maintain the accuracy and quality of the pattern formed in advance, it is necessary to protect the already formed pattern in any of the lithography processes.
As described above, in the recent manufacturing process of double-sided masks, various processes are mixed in order to maintain pattern accuracy and quality, and it is important in which process an already formed pattern is protected.

  The present invention has been made in view of the above problems, and in a method for producing a double-sided mask having patterns on both sides of a transparent substrate, both sides provided with a protective layer for protecting the pattern formed on one side of the transparent substrate. An object is to provide a method for manufacturing a mask.

In order to solve the above-mentioned problems in the present invention, first, in claim 1, a method for producing a double-sided mask having a pattern on both sides of a transparent substrate, comprising at least the following steps: This is a manufacturing method.
(A) A step of forming a pattern on one surface of the transparent substrate.
(B) A step of forming a light shielding layer and a resist layer on the other surface of the transparent substrate and drawing a pattern.
(C) A step of forming a protective layer on one surface of the transparent substrate.
(D) A step of forming a pattern on the other surface of the transparent substrate.
(E) A step of removing the protective layer.

Moreover, in Claim 2, it is set as the manufacturing method of the double-sided mask of Claim 1 characterized by including the following processes at least.
(A) A step of forming the light shielding layer 21 on one surface of the transparent substrate 11.
(B) A step of forming a resist layer 31 by applying a resist on the light shielding layer 21.
(C) A step of performing a patterning process such as pattern drawing and development on the resist layer 31 to form a resist pattern 31a.
(D) A step of forming the main pattern 21a by etching the light shielding layer 21 using the resist pattern 31a as a mask and stripping the resist pattern 31a.
(E) A step of forming the light shielding layer 22 on the other surface of the transparent substrate 11 on which the main pattern 21a is formed.
(F) A step of forming a resist layer 32 by applying a resist on the light shielding layer 22.
(G) A step of drawing a pattern on the resist layer 32 to form a resist layer 32a on which a pattern latent image is formed.
(H) A step of attaching a protective sheet 40 having an adhesive layer 42 formed around the film sheet 41 and forming a protective layer 43 on the surface of the main pattern 21 a of the transparent substrate 11.
(I) A step of developing the resist layer 32a on which the pattern latent image is formed to form a resist pattern 32b.
(J) A step of etching the light shielding layer 22 using the resist pattern 32b as a mask and stripping the resist pattern 32b to form the pattern 22a.

  Furthermore, in claim 3, the protective layer 43 is formed by attaching a protective sheet 40 having an adhesive layer 42 to the periphery of the film sheet 41, and the adhesive layer 42 of the protective sheet 40 is formed on the transparent substrate 11. 3. The method for producing a double-sided mask according to claim 1, wherein the double-sided mask is formed at a position corresponding to a peripheral portion outside the pattern region.

According to the method for producing a double-sided mask of the present invention, a protective layer for protecting a pattern formed on one surface of a transparent substrate is formed at the time when the pattern drawing of the resist layer on the other surface of the transparent substrate is completed. Therefore, even if pattern drawing is performed by electron beam exposure, it is possible to prevent the influence of the lowering of vacuum due to outgas due to the influence of the protective layer, and damage to the pattern formed on one surface in the wet etching process of the light shielding layer And the pattern accuracy and quality of the double-sided mask can be maintained.
Further, the protective layer is formed by sticking a protective sheet having an adhesive layer on the periphery of the film sheet, and the protective sheet is fixed by the adhesive layer on the peripheral part of the transparent substrate. Sometimes it is possible to prevent the effective portion of the pattern area of the transparent substrate from being damaged, and at the same time, after the protective sheet is peeled off, foreign matter such as the adhesive residue may adhere to the pattern area of the transparent substrate. Without the occurrence of residual defects due to foreign matter,

An embodiment of the invention will be described.
1A to 1D, 2E to 2H, and 3I to 3K are schematic cross-sectional views showing an embodiment of a method for manufacturing a double-sided mask of the present invention. is there.
In the method for producing a double-sided mask according to the first or second aspect of the present invention, the light-shielding layer 21 and the resist layer 31 are formed on one surface of the transparent substrate 11, and pattern drawing on the resist layer 31, development processing, After forming a pattern 21a by performing a series of patterning processes such as etching and resist pattern 31a peeling, a light shielding layer 22 and a resist layer 32 are formed on the other surface of the transparent substrate 11, and a pattern is drawn to form a pattern latent image. After forming the formed resist layer 32a, a protective layer 43 is formed on the pattern 21a on one surface of the transparent substrate 11, and the development of the resist layer 32a on which the pattern latent image on the other surface of the transparent substrate 11 is formed. The pattern 22a is applied to the other surface of the transparent substrate 11 by performing a series of patterning processes such as processing, etching of the light shielding layer 22, and peeling of the resist pattern 32b. Form, is that to obtain a double-sided mask 100 pattern 21a and pattern 22a is formed on both surfaces of the transparent substrate 11.

  As described above, in the method for producing a double-sided mask according to the present invention, after forming the pattern 21a on one surface of the transparent substrate 11, the light shielding layer 22 and the resist layer 32 are formed on the other surface of the transparent substrate 11, and the pattern is drawn. In order to form the protective layer 43 on one surface of the transparent substrate 11 after forming the resist layer 32a on which the pattern latent image is formed, when performing pattern drawing by electron beam exposure, the degree of vacuum due to outgas etc. of the film sheet and the adhesive layer Patterns can be drawn by electron beam exposure without being affected by the decrease. Further, it is natural that the damage prevention effect by the protective layer of the pattern 21a can be obtained.

Hereinafter, a method for producing a double-sided mask of the present invention will be described in detail.
First, a light shielding layer 21 made of chromium, a chromium oxide film or the like is formed on one surface of the transparent substrate 11 (see FIG. 1A).
Next, a resist is applied on the light shielding layer 21 to form a resist layer 31 (see FIG. 1B).

Next, a pattern is drawn on the resist layer 31 and developed to form a resist pattern 31a (see FIG. 1C).
Here, the pattern drawing method may be any of pattern exposure using light and photomask and pattern drawing using an electron beam exposure apparatus.

Next, the light shielding layer 21 is etched using the resist pattern 31a as a mask, and the resist pattern 31a is stripped to form the main pattern 21a (see FIG. 1D). The light shielding layer 21 is etched by wet etching.
The peeling process of the resist pattern 31a may be either a peeling process using a dedicated peeling solution or a dry ashing process using a plasma process.

Next, a light shielding layer 22 made of chromium, a chromium oxide film or the like is formed on the other surface of the transparent substrate 11 having the main pattern 21a formed on one surface (see FIG. 2E).
Next, a resist is applied on the light shielding layer 22 to form a resist layer 32 (see FIG. 2F).

Next, after alignment with the alignment mark formed on one surface of the transparent substrate 11, pattern drawing is performed on the resist layer 32 to form a resist layer 32a on which a pattern latent image is formed (FIG. 2). (See (g)).
Here, the pattern drawing method may be any of pattern exposure using light and photomask and pattern drawing using an electron beam exposure apparatus. However, since a protective layer is not yet formed, an electron beam exposure apparatus is used. Good pattern drawing can be performed in pattern drawing using.

Next, a protective sheet 40 having an adhesive layer 42 formed around the film sheet 41 is attached to one surface of the transparent substrate 11 to form a protective layer 43 on the transparent substrate 11 and the main pattern 21a (FIG. 2 ( h)).
Here, as shown in FIGS. 4 (a) and 4 (b), the protective layer 43 is prepared by attaching the adhesive layer 42 to the peripheral portion of the film sheet 41 to produce the protective sheet 40. The layer 42 is formed at a position corresponding to the peripheral portion outside the pattern area of the transparent substrate 11.
As the film sheet 41, a resin film base material excellent in chemical resistance is preferable. For example, polyethylene terephthalate (PET), polyimide (PI) and the like.
As the adhesive layer 42, an acrylic adhesive or the like can be used.

  Next, the resist layer 32a on which the pattern latent image is formed is developed to form a resist pattern 32b (see FIG. 3I).

Next, the light shielding layer 22 is etched using the resist pattern 32b as a mask, and the resist pattern 32b is stripped to form a pattern 22a (see FIG. 3J).
The light shielding layer 22 is etched by wet etching.
The resist pattern 32b may be stripped by either wet stripping using a dedicated stripping solution or dry ashing by plasma processing.

  Finally, the protective sheet 40 is peeled off to remove the protective layer 43 to obtain a double-sided mask 100 in which the main pattern 21a is formed on one surface of the transparent substrate 11 and the pattern 22a is formed on the other surface (FIG. 3 (k )reference).

(A)-(d) is typical structure sectional drawing which shows a part of process of one Example of the manufacturing method of the double-sided mask of this invention. (E)-(h) is typical structure sectional drawing which shows a part of process of one Example of the preparation methods of the double-sided mask of this invention. (Ik) is a schematic cross-sectional view showing a part of the process of one embodiment of the method for producing a double-sided mask of the present invention. (A) is a top view which shows one Example of a protection sheet. (B) is a schematic cross-sectional view showing an example of a protective sheet cut along line A-A ′. (A)-(e) is typical structure sectional drawing which shows a part of process of the manufacturing method of the conventional double-sided mask. (F)-(h) is typical structure sectional drawing which shows a part of process of the manufacturing method of the conventional double-sided mask.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 111 ... Transparent board | substrate 21, 22 ... Light-shielding layer 21a ... Main pattern 22a, 111a, 111b ... Pattern 31, 32 ... Resist layer 31a, 32b, 121a, 122a ... Resist pattern 32a ... Resist layer in which pattern latent image was formed 40 ... protective sheet 41 ... film sheet 42 ... adhesive layer 43 ... protective layer 100 ... double-sided mask 111a '... alignment mark 121 ... first resist layer 122 ... second resist layer

Claims (3)

A method for producing a double-sided mask having a pattern on both sides of a transparent substrate, comprising at least the following steps.
(A) A step of forming a pattern on one surface of the transparent substrate.
(B) A step of forming a light shielding layer and a resist layer on the other surface of the transparent substrate and drawing a pattern.
(C) A step of forming a protective layer on one surface of the transparent substrate.
(D) A step of forming a pattern on the other surface of the transparent substrate.
(E) A step of removing the protective layer. The method for producing a double-sided mask according to claim 1, comprising at least the following steps.
(A) A step of forming a light shielding layer (21) on one surface of the transparent substrate (11).
(B) A step of applying a resist on the light shielding layer (21) to form a resist layer (31). (C) A step of forming a resist pattern (31a) by performing patterning processing such as pattern drawing and development on the resist layer (31).
(D) A step of forming the main pattern (21a) by etching the light shielding layer (21) using the resist pattern (31a) as a mask, and removing the resist pattern (31a).
(E) A step of forming a light shielding layer (22) on the other surface of the transparent substrate (11) on which the main pattern (21a) is formed.
(F) A step of applying a resist on the light shielding layer (22) to form a resist layer (32). (G) A step of drawing a pattern on the resist layer (32) to form a resist layer (32a) on which a pattern latent image is formed.
(H) A step of attaching a protective sheet (40) having an adhesive layer (42) formed around the film sheet (41) and forming a protective layer (43) on the main pattern (21a) surface of the transparent substrate (11). .
(I) A step of developing the resist layer (32a) on which the pattern latent image is formed to form a resist pattern (32b).
(J) A step of etching the light shielding layer (22) using the resist pattern (32b) as a mask and stripping the resist pattern (32b) to form a pattern (22a).
(K) A step of removing the protective layer (41).   The protective layer (43) is formed by sticking a protective sheet (40) having an adhesive layer (42) on the periphery of the film sheet (41), and the adhesive layer (42) of the protective sheet (40) is the transparent layer. The method for producing a double-sided mask according to claim 1 or 2, wherein the double-sided mask is formed at a position corresponding to a peripheral portion outside the pattern region of the substrate (11).

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