TW202309663A - Photomask, method for making same, and exposure method - Google Patents

Abstract

Embodiments of the present application provide a photomask, a method for making the photomask, and an exposure method. The photomask includes: a transparent substrate having a first surface; a patterned light shielding layer on the first surface; and a diffusion layer on a side of the substrate away from the light shielding layer. The diffusion layer includes light diffusing particles.

Description

Photomask, its preparation method, and exposure method

The invention relates to the technical field of semiconductors, in particular to a photomask, a preparation method and an exposure method thereof.

In the conventional touch panel, the touch driving electrodes (or touch sensing electrodes) need to form via holes on the insulating layer to realize the bridging of the conductive layer. The insulating layer (photoresist material, such as dry film) is exposed and developed through a photomask to form through holes. However, in the conventional manufacturing process, the through hole of the insulating layer has an undercut (Undercut) and the inclination angle (Taper) is too large, which causes disconnection when the conductive layer is bridged.

The first aspect of the present application provides a photomask, which includes: A transparent substrate having a first surface; a patterned light-shielding layer on the first surface; and The diffusion layer is located on the side of the substrate away from the light shielding layer, and the diffusion layer contains light diffusion particles.

The photomask has a diffusion layer, which contains light diffusion particles. After the light from the exposure light source passes through the mask, the diffusion layer can refract and diffuse the light from the light source, so that the light from the exposure light source is deflected and emitted uniformly, thereby improving the phenomenon of undercut and excessive inclination angle of the photoresist after exposure. When the photomask is applied to the preparation of touch panels to pattern the insulating layer (photoresist material, such as dry film) to form through holes and realize the bridging of touch driving electrodes or touch sensing electrodes, the insulation can be improved The undercut of the layer at the through hole and the problem of excessive inclination angle can be solved, and the conductive layer can be effectively overlapped.

In some embodiments of the present application, the substrate has a second surface opposite to the first surface, and the diffusion layer is located on the second surface; or, the photomask includes a The substrate on one side of the light-shielding layer, and the diffusion layer is located on the surface of the substrate away from the substrate.

In some embodiments of the present application, the photomask further includes an antistatic layer, and the antistatic layer covers at least the surface of the light-shielding layer away from the substrate and the surface of the first surface not covered by the light-shielding layer. part; where the photomask includes the substrate, the antistatic layer also covers a surface of the substrate close to the substrate.

In some embodiments of the present application, the antistatic layer contains carbon oxide antistatic particles.

In some embodiments of the present application, the diffusion layer has a thickness of 1 μm to 10 μm and/or the antistatic layer has a thickness of 4 μm to 5 μm.

In some embodiments of the present application, the substrate is made of glass or plastic.

The second aspect of the present application provides a method for preparing a photomask, which includes: A patterned light-shielding layer and a diffusion layer are respectively formed on the opposite first surface and the second surface of a transparent substrate, and the diffusion layer contains light-diffusing particles; and An antistatic layer is formed, and the antistatic layer covers the surface of the light-shielding layer away from the substrate and the part of the first surface not covered by the light-shielding layer.

According to the preparation method of the photomask, the obtained photomask has both light diffusion function and antistatic function.

The third party of this application provides an exposure method, which includes: Place the workpiece to be exposed on the stage of the exposure machine; placing a diffusion plate between the light source and the mask of the exposure machine, the diffusion plate includes a diffusion layer containing light diffusion particles; and Expose the workpiece to be exposed.

In some embodiments of the present application, the diffusion plate further includes a base material and an antistatic layer, and the diffusion layer and the antistatic layer are respectively located on two opposite surfaces of the base material.

In some embodiments of the present application, the diffusion plate is attached to the photomask; or the diffusion plate is attached between the exposure glass of the exposure machine and the photomask; or the diffusion plate The side of the exposure glass attached to the exposure machine away from the photomask.

In this exposure method, since the diffusion layer in the diffusion plate contains light diffusion particles, after the light of the exposure light source passes through the mask, the diffusion layer can refract and diffuse the light of the light source, so that the light of the exposure light source is deflected and emitted uniformly, and then Improve the phenomenon of undercut and excessive tilt angle after photoresist exposure. When this exposure method is applied to the preparation of the touch panel to form a via hole on the insulating layer (photoresist material, such as a dry film) to realize the formation of the conductive layer bridge of the touch drive electrode or touch sensing electrode, it can improve The undercut of the insulating layer at the through hole and the problem of excessive inclination angle can realize effective overlapping of the conductive layer.

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some of the embodiments of the present invention, but not all of them.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field of the invention. The terms used herein in the description of the present invention are for the purpose of describing specific embodiments only, and are not intended to limit the present invention.

In order to further explain the technical means and effects adopted by the present invention to achieve the intended purpose, the present invention will be described in detail below in conjunction with the accompanying drawings and preferred embodiments.

Some embodiments of the present application provide a photomask. The photomask includes a transparent substrate, a patterned light-shielding layer, and a diffusion layer. Wherein, the patterned light-shielding layer is located on the first surface of the substrate, the diffusion layer is located on the side of the substrate away from the light-shielding layer, and the diffusion layer contains light-diffusing particles.

The photomask has a diffusion layer, and the diffusion layer contains light diffusion particles. After the light from the exposure light source passes through the mask, the diffusion layer can refract and diffuse the light from the light source, so that the light from the exposure light source is deflected and emitted uniformly, thereby improving the phenomenon of undercut and excessive inclination angle of the photoresist after exposure. When the photomask is applied to the preparation of touch panels to pattern the insulating layer (photoresist material, such as dry film) to form through holes and realize the bridging of touch driving electrodes or touch sensing electrodes, the insulation can be improved The undercut of the layer at the through hole and the problem of excessive inclination angle can be solved, and the conductive layer can be effectively overlapped.

In some embodiments of the present application, the substrate is made of plastic, such as polyethylene terephthalate (PET), and the mask is a film mask. In other embodiments of the present application, the substrate is made of glass (eg, quartz), and the photomask is a glass photomask.

It will be described in detail below with reference to FIG. 1 and FIG. 2 .

FIG. 1 is a schematic diagram of exposure using a film mask 10 with a diffusion layer provided by some embodiments of the present application. As shown in FIG. 1 , the photomask 10 includes a substrate 12 . The substrate 12 has a first surface 121 and a second surface 122 opposite to each other. The patterned light shielding layer 13 is located on the first surface 121 of the substrate 12 . The diffusion layer 11 is located on the second surface 122 . The photomask 10 also includes an antistatic layer 14 to avoid static electricity generated during the operation of the photomask 10 . The antistatic layer 14 covers the surface of the light shielding layer 13 away from the substrate 12 and the portion of the first surface 121 not covered by the light shielding layer 13 . That is, the antistatic layer 14 is provided on the surface of the light shielding layer 13 away from the substrate 12 . The portion of the first surface 121 of the substrate 12 not covered by the light-shielding layer 13 is also provided with the antistatic layer 14 .

In some embodiments of the present application, the light diffusing particles in the diffusing layer 11 are diffusing particles of metal oxide (eg, zirconia). The thickness of the diffusion layer 11 is 1 μm to 10 μm, further 3 μm to 5 μm. The material of the patterned light-shielding layer 13 is, for example, a photosensitive material such as silver halide. The antistatic layer 14 contains antistatic particles of carbon oxides. The thickness of the antistatic layer 14 is 4 μm˜5 μm.

Specifically, the method of using the photomask 10 for exposure includes: placing the workpiece 30 to be exposed on the stage 43 of the exposure machine; attaching the photomask 10 to the exposure glass 42 of the exposure machine; The light source 41 exposes the workpiece 30 to be exposed. The workpiece 30 to be exposed may include a substrate 31 and a photoresist layer 32 on the substrate 31 . The light source 41 of the exposure machine may be an ultraviolet exposure light source 41 .

After the light from the light source 41 of the exposure machine passes through the mask 10, the light-diffusing particles in the diffusion layer 11 will regulate the light incident on it to refract, diffuse and homogenize the light, thereby improving the patterned photoresist. Layer 32 slope angle and undercut issues. In some embodiments, the patterned photoresist layer 32 obtained by exposing with the mask 10 has no undercut phenomenon, and the taper angle is ≤45°. When the photomask 10 is applied to the preparation of the touch panel to pattern the insulating layer (photoresist material, such as a dry film) to form a through hole and realize the bridging of the touch driving electrodes or the touch sensing electrodes, the improvement can be improved. The undercut of the insulating layer at the through hole and the problem of excessive inclination angle can realize effective overlapping of the conductive layer.

FIG. 2 is a schematic diagram of exposure using a glass mask with a diffusion layer provided by some embodiments of the present application. The difference between the photomask shown in FIG. 2 and the photomask in FIG. 1 is that the photomask 10 in FIG. 2 is a glass photomask, the material of its substrate 12 is quartz, and the material of its patterned light-shielding layer 13 is chromium. Its thickness is about tens of nanometers. The photomask 10 in FIG. 1 is a film photomask, the material of the substrate 12 is PET, and the light-shielding layer 13 is photosensitive material such as silver halide. In addition, FIG. 2 is a glass photomask, and it is not necessary to attach the photomask 10 to the exposure glass 42 of the exposure machine during exposure. In addition, the thicknesses and materials of the diffusion layer 11 and the antistatic layer 14 in FIG. 2 are the same as those in FIG. 1 , and will not be repeated here.

Since the glass photomask in FIG. 2 has the same diffusion layer 11 and antistatic layer 14 as in FIG. 1, it has a function similar to that of the film photomask in FIG. 1, which can improve the bottom of the photoresist layer during exposure. It can solve the problem of excessive cutting and inclination angle, and can eliminate the static electricity generated during the operation of the photomask.

It should be noted that, in FIG. 1 and FIG. 2 , the diffusion layer is embedded in the photomask and exists as a film layer of the photomask. In other embodiments of the present application, the diffusion layer may be disposed on the surface of the substrate to form a diffusion plate. The base material is, for example, a PET film. The diffusion plate can be an external hanging type, which exists independently of the mask. The method of using the diffuser plate for exposure includes: placing the workpiece to be exposed on the stage of the exposure machine; placing the diffuser plate between the light source of the exposure machine and the mask; and exposing the workpiece to be exposed. Specifically, the diffusion plate can be attached to the photomask; or the diffusion plate is attached between the exposure glass of the exposure machine and the photomask; or the diffusion plate is attached to the exposure glass of the exposure machine away from the photomask side. That is to say, the embedded diffusion layer can be directly formed (eg, coated) on the surface of the substrate during the process of making the photomask. For the external diffuser plate, the diffuser layer can be coated on the base material to form a coil, and then cut into the required size of the diffuser plate, and then the diffuser plate is attached to the film mask or glass mask or exposure different positions of the glass. The diffusion plate may also include an antistatic layer, and the diffusion layer and the antistatic layer are respectively arranged on two opposite surfaces of the substrate.

Below in conjunction with accompanying drawing 3 to 5 concrete description.

As shown in FIG. 3 , the diffusion plate 20 is attached between the exposure glass 42 of the exposure machine and the photomask 10 . The diffuser plate 20 includes a base material 22 and a diffuser layer 21 and an antistatic layer 24 disposed on opposite sides of the base material 22 . The side of the diffusion plate 20 provided with the diffusion layer 21 is attached to the exposure glass 42 . The mask 10 is a film mask, which includes a transparent substrate 12 and a patterned light-shielding layer 13 on the substrate 12 . The material of the substrate 12 is plastic, such as PET.

As shown in FIG. 4 , the diffusion plate 20 is attached to the side of the exposure glass 42 of the exposure machine away from the film mask 10 . The side of the diffusion plate 20 provided with the antistatic layer 24 is attached to the exposure glass 42 . The mask 10 is a film mask, which includes a transparent substrate 12 and a patterned light-shielding layer 13 on the substrate 12 . The material of the substrate 12 is plastic, such as PET.

As shown in FIG. 5 , the side of the diffusion plate 20 provided with the antistatic layer 24 is attached to the photomask 10 . The photomask 10 is a glass photomask, which includes a transparent substrate 12 and a patterned light-shielding layer 13 on the substrate 12 . The material of the substrate 12 is glass, such as quartz glass.

In FIGS. 3 to 5 , the material of the diffusion layer 21 is the same as that of the diffusion layer 11 in FIGS. 1 and 2 , and its light diffusion particles are metal oxide (eg, zirconia) diffusion particles. The thickness of the diffusion layer 21 is 1 μm to 10 μm, further 3 μm to 5 μm. The material of the antistatic layer 24 is the same as that of the antistatic layer 14 in FIG. 1 and FIG. 2 , and it contains carbon oxide antistatic particles. The thickness of the antistatic layer 4 is 4 μm˜5 μm.

3 to 5, the light from the exposure light source 41 passes through the diffusion plate 20 before entering the photoresist layer 32, and is refracted by the light-diffusing particles in the diffusion layer 21 included in the diffusion plate 20 to achieve uniformity. Furthermore, problems of tilt angle and undercut of the patterned photoresist layer 32 can be improved. In addition, the diffusion plate 20 includes an antistatic layer 24 , which can also prevent static electricity generated during the operation of the photomask 10 .

In some embodiments, the diffuser plate 20 may also not include the antistatic layer 24 .

In some embodiments, the diffusion plate 20 shown in FIG. 5 and the photomask 10 constitute an independent photomask, rather than the diffuser plate 20 being hung on the photomask 10 to be separated into two products. That is, an independent photomask includes a diffusion layer 21 , a substrate 22 , an antistatic layer 24 , a transparent substrate 12 and a patterned light-shielding layer 13 stacked in sequence.

To sum up, in the embodiment of the present application, the diffusion layer may be embedded in a film mask (as shown in FIG. 1 ), or embedded in a glass mask (as shown in FIG. 2 ). Alternatively, the diffusion layer is arranged on the surface of a substrate to form a diffusion plate, and the diffusion plate is hung (or attached) between the film mask and the exposure glass (as shown in Figure 3); or the diffusion plate is hung on (or attached to) the side of the exposure glass away from the film mask (as shown in Figure 4); or the diffuser is hung on (or attached to) the glass mask (as shown in Figure 5). Since the diffusion layer can deflect and homogenize the light from the exposure light source, it can improve the problems of undercutting and excessive inclination of the photoresist layer during the exposure process.

In some embodiments, the polarization angle of the diffusion layer covers an angle range of 1° to 80°, and the tilt angle of the photosensitive material (negative or positive dry film, or negative or positive photoresist) can be optimized, so that the tilt angle Less than or equal to 45°, the reflow range is 3μm~6μm.

Some embodiments of the present application also provide a method for preparing a photomask. The preparation method comprises: respectively forming a patterned light-shielding layer and a diffusion layer on the opposite first surface and second surface of a transparent substrate, the diffusion layer containing light diffusion particles; and forming an antistatic layer, the The antistatic layer covers the surface of the light-shielding layer away from the substrate and the part of the first surface not covered by the light-shielding layer.

The preparation steps of the film mask will be described below with reference to FIGS. 6 to 10 . That is, in FIGS. 6 to 10 , the substrate is made of plastic, such as PET.

As shown in FIG. 6, a transparent substrate 12 is provided. The substrate 12 has a first surface 121 and a second surface 122 opposite to each other. The light shielding layer 13 is formed on the first surface 121 . The material of the light-shielding layer 13 is, for example, a photosensitive material such as silver halide.

As shown in FIG. 7 , the diffusion layer 11 is coated on the second surface 122 of the substrate 12 . The diffusion layer 11 contains diffusion particles of metal oxide.

As shown in FIG. 8 , a pattern is written in the light-shielding layer 13 using an electron beam. Since the plastic is a flexible board, patterns can be written directly by electron beams without a photoresist layer.

As shown in FIG. 9 , the portion of the light-shielding layer 13 not exposed to the electron beam is removed by a developing process, and a patterned light-shielding layer 13 is obtained on the first surface 121 of the substrate 12 .

As shown in FIG. 10 , an antistatic layer 14 is coated on one side of the first surface 121 of the substrate 12 . The antistatic layer 14 covers the surface of the patterned light-shielding layer 13 away from the substrate 12 and the portion of the first surface 121 of the substrate 12 not covered by the light-shielding layer 13 . Thereby, the photomask which has light-diffusion function and antistatic function is obtained.

In other embodiments of the present application, the substrate is made of glass. The manufacturing method of the glass mask is shown in Fig. 11 to Fig. 15 .

As shown in FIG. 11, a transparent substrate 12 is provided. The material of the substrate 12 is quartz glass, which has a first surface 121 and a second surface 122 opposite to each other. The light shielding layer 13 is formed on the first surface 121 . The material of the light-shielding layer 13 is, for example, chromium, which can be formed by deposition, with a thickness of about tens of nanometers.

As shown in FIG. 12 , the diffusion layer 11 is coated on the second surface 122 of the substrate 12 . The diffusion layer 11 contains diffusion particles of metal oxide.

As shown in FIG. 13 , a pattern is written in the light-shielding layer 13 using an electron beam. Since the quartz glass is a hard plate, it needs to form a photoresist layer 15 on the light shielding layer 13, and then use an electron beam to write the pattern.

As shown in FIG. 14 , the part of the photoresist layer 15 exposed to the electron beam is removed by a developing process, and then the part of the light shielding layer 13 exposed by the patterned photoresist layer 15 is removed by an etching process, and then on the first surface of the substrate 12 121 to obtain a patterned light-shielding layer 13 .

As shown in FIG. 15 , after the patterned photoresist layer 15 is removed and cleaned, an antistatic layer 14 is coated on one side of the first surface 121 of the substrate 12 . The antistatic layer 14 covers the surface of the patterned light-shielding layer 13 away from the substrate 12 and the portion of the first surface 121 of the substrate 12 not covered by the light-shielding layer 13 . Thereby, the photomask which has light-diffusion function and antistatic function is obtained.

The above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced. Without departing from the spirit and scope of the technical solutions of the present invention.

10: Mask 11, 21: Diffusion layer 12: Substrate 121: first surface 122: second surface 13: Shading layer 14, 24: antistatic layer 20: Diffusion plate 22: Substrate 30: Workpiece 31: Substrate 32, 15: photoresist layer 41: light source 42: Exposure glass 43: Carrier

FIG. 1 is a schematic diagram of exposure using a film mask with a diffusion layer provided by some embodiments of the present application.

FIG. 2 is a schematic diagram of exposure using a glass mask with a diffusion layer provided by some embodiments of the present application.

FIG. 3 is a schematic diagram of a diffusion plate attached between an exposure glass and a film mask of an exposure machine for exposure in some embodiments of the present application.

FIG. 4 is a schematic diagram of a diffusion plate attached to the side of the exposure glass of the exposure machine away from the film mask for exposure in some embodiments of the present application.

FIG. 5 is a schematic diagram of a diffusion plate attached to a glass mask for exposure in some embodiments of the present application.

FIG. 6 is a schematic diagram of forming a light-shielding layer on the first surface of the substrate in some embodiments of the present application.

FIG. 7 is a schematic diagram of forming a diffusion layer on the second surface of the substrate in some embodiments of the present application.

FIG. 8 is a schematic diagram of patterning a light-shielding layer in some embodiments of the present application.

FIG. 9 is a schematic diagram of a patterned light-shielding layer formed in some embodiments of the present application.

FIG. 10 is a schematic diagram of forming an antistatic layer in some embodiments of the present application.

FIG. 11 is a schematic diagram of forming a light-shielding layer on the first surface of the substrate in other embodiments of the present application.

FIG. 12 is a schematic diagram of forming a diffusion layer on the second surface of the substrate in other embodiments of the present application.

FIG. 13 is a schematic diagram of patterning a light-shielding layer in other embodiments of the present application.

FIG. 14 is a schematic diagram of a patterned light-shielding layer formed in other embodiments of the present application.

FIG. 15 is a schematic diagram of forming an antistatic layer in other embodiments of the present application.

10: Mask

11: Diffusion layer

12: Substrate

121: first surface

122: second surface

13: Shading layer

14: Antistatic layer

30: Workpiece

31: Substrate

32: photoresist layer

41: light source

42: Exposure glass

43: Carrier

Claims (10)

A photomask, which is improved in that it includes: A transparent substrate having a first surface; a patterned light-shielding layer on the first surface; and The diffusion layer is located on the side of the substrate away from the light shielding layer, and the diffusion layer contains light diffusion particles. The photomask according to claim 1, wherein the substrate has a second surface opposite to the first surface, and the diffusion layer is located on the second surface; or, the photomask includes a The substrate is on the side of the substrate away from the light shielding layer, and the diffusion layer is located on the surface of the substrate away from the substrate. The photomask according to claim 2, wherein the photomask further includes an antistatic layer, and the antistatic layer covers at least the surface of the light-shielding layer away from the substrate and the first surface is not shielded from light by the light-shielding layer The portion covered by the layer; where the photomask includes the substrate, the antistatic layer also covers the surface of the substrate that is close to the substrate. The photomask according to claim 3, wherein the antistatic layer contains carbon oxide antistatic particles. The mask according to claim 3, wherein the diffusion layer has a thickness of 1 μm to 10 μm and/or the antistatic layer has a thickness of 4 μm to 5 μm. The photomask according to any one of claims 1 to 5, wherein the substrate is made of glass or plastic. A method for preparing a photomask, comprising: A patterned light-shielding layer and a diffusion layer are respectively formed on the opposite first surface and the second surface of a transparent substrate, and the diffusion layer contains light-diffusing particles; and An antistatic layer is formed, and the antistatic layer covers the surface of the light-shielding layer away from the substrate and the part of the first surface not covered by the light-shielding layer. A method of exposure, comprising: Place the workpiece to be exposed on the stage of the exposure machine; placing a diffusion plate between the light source and the mask of the exposure machine, the diffusion plate includes a diffusion layer containing light diffusion particles; and Expose the workpiece to be exposed. The exposure method according to claim 8, wherein the diffusion plate further includes a base material and an antistatic layer, and the diffusion layer and the antistatic layer are respectively located on two opposite surfaces of the base material. The exposure method according to claim 8 or 9, wherein the diffuser plate is attached to the photomask; or the diffuser plate is attached between the exposure glass of the exposure machine and the photomask; Or the diffusion plate is attached to the side of the exposure glass of the exposure machine away from the photomask.

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