JP-7139133-B2 - Pellicle frame, pellicle, and method for manufacturing pellicle frame

Inventors

• 濱田 裕一

Assignees

• 信越化学工業株式会社
• 信越化学工業株式会社

Dates

Publication Date

20220920

Application Date

20180403

Priority Date

20180403

Claims (13)

1. a frame base material, a black anodized coating with a thickness of 2.0 to 7.5 μm formed on the surface of the frame base material, and a transparent polymer electrodeposition coating formed on the anodized coating; with The pellicle frame , wherein the transparent polymer electrodeposition coating film has a visible light transmittance of more than 50%, the anodized film is sulfuric acid alumite, and the L value is 35 or less .
2. 2. The pellicle frame according to claim 1, wherein said transparent polymer electrodeposited coating does not contain non-uniform components existing non-uniformly with respect to said transparent polymer electrodeposited coating.
3. 3. The pellicle frame according to claim 1, wherein the transparent polymer electrodeposition coating contains no dye.
4. 4. The pellicle frame according to any one of claims 1 to 3, which is a pellicle frame used for an ArF laser exposure pellicle.
5. A pellicle comprising: the pellicle frame according to any one of claims 1 to 4; and a pellicle film provided on one end surface of the pellicle frame.
6. a step of forming an anodized film with a thickness of 2.0 to 7.5 μm on the surface of the frame base material by a sulfuric acid method ; a step of coloring the anodized film black; forming a transparent polymer electrodeposition coating on the anodized coating, wherein the transparent polymer electrodeposition coating has a visible light transmittance of more than 50% ; A method for manufacturing a pellicle frame having an L value of 35 or less .
7. A pellicle-attached exposure original plate comprising the pellicle according to claim 5 mounted on an exposure original plate.
8. An exposure method comprising exposing using the pellicle according to claim 5 .
9. 9. The exposure method according to claim 8, wherein said exposure is exposure with an ArF laser.
10. 6. A method of manufacturing a semiconductor device, comprising the step of exposing using the pellicle according to claim 5.
11. 11. The method of manufacturing a semiconductor device according to claim 10, wherein said exposure is exposure with an ArF laser.
12. 6. A method of manufacturing a liquid crystal display, comprising the step of exposing using the pellicle according to claim 5.
13. 13. The method of manufacturing a liquid crystal display according to claim 12, wherein said exposure is exposure with an ArF laser.

Description

The present invention relates to a pellicle for lithography used as a dust cover for a photomask in the manufacture of semiconductor devices, liquid crystal displays, etc., a pellicle frame constituting the same, and a method for manufacturing the pellicle frame. 2. Description of the Related Art In the manufacture of semiconductor devices such as LSIs and super LSIs, liquid crystal displays, etc., a photolithographic technique is used in which a pattern is formed by irradiating a semiconductor wafer or a master plate for liquid crystals with light. In this photolithography process, if dust adheres to the photomask (exposure original plate), the dust absorbs or bends the light, resulting in deformation of the transferred pattern, rough edges, and underlayment. There was a problem that the size, quality, and appearance were impaired, such as black stains. Therefore, these operations are usually performed in a clean room, but it is difficult to keep the photomask completely clean even in the clean room. Therefore, it is common practice to mount a pellicle on the surface of the photomask, which allows the exposure light to pass therethrough, in order to remove dust. As a result, dust does not adhere directly to the surface of the photomask, but adheres to the pellicle film. Therefore, if the pattern on the photomask is focused during exposure, dust on the pellicle film is irrelevant to transfer. FIG. 2 shows the configuration of a typical pellicle. The pellicle has a pellicle film 101 on the upper end surface of the pellicle frame 102 , which allows the exposure light to pass through well, and is stretched via an adhesive 103 . An adhesive layer 104 is formed. Moreover, a separator (not shown) for protecting the adhesive layer 104 may be detachably provided on the lower end surface of the adhesive layer 104 . Such a pellicle is installed so as to cover the pattern area 106 formed on the surface of the photomask. Therefore, the pattern area 106 is isolated from the outside by the pellicle, and dust is prevented from adhering to the photomask. In recent years, the design rule of LSI has been miniaturized to sub-quarter microns, and along with this, the size of particles to be suppressed for contamination is becoming smaller. In addition, the wavelength of the exposure light source is becoming shorter, and fine particles that cause haze are more likely to be generated by exposure. This is because the energy of the light increases as the wavelength of the exposure becomes shorter, and gaseous substances present in the exposure atmosphere react with each other to produce a reaction product on the mask substrate. For example, acids such as sulfuric acid, nitric acid, and organic acids are incorporated into the anodized film on the aluminum alloy surface used for the pellicle frame. This desorbs from the anodized film on the surface of the frame under the exposure environment and stays in the space between the pellicle and the mask. In this state, a sulfuric acid compound such as ammonium sulfate is generated by exposure to short wavelength ultraviolet rays. Therefore, conventional alumite-treated (anodized) frames contain sulfate ions and are therefore being avoided. Thus, for example, Patent Document 1 proposes a pellicle coated with a polymer as a frame from which sulfate ions are not eluted, and as the polymer coat, a black matte electrodeposition paint film using a matte paint colored with a black pigment is proposed. disclosed. Further, Patent Document 2 discloses a pellicle in which a pure aluminum film is formed on the surface of a frame base material made of an aluminum alloy, anodized and black-dyed, and then a transparent acrylic resin film is formed by electrodeposition coating. A frame is disclosed. The pure aluminum coating covers crystallized substances on the aluminum alloy surface that cause bright spots (defects) misidentified as foreign matter on the surface of the pellicle frame, and improves the appearance quality and reliability of the pellicle. . Japanese Patent Application Laid-Open No. 2007-333910JP 2014-206661 A It is a cross-sectional schematic diagram of the pellicle which concerns on one form of this invention.It is a cross-sectional schematic diagram which shows the general structure of the conventional pellicle. Embodiments of the present invention will be described in detail below, but the present invention is not limited to these. [1] Pellicle Frame The pellicle frame according to the present embodiment includes a frame base material, a black anodized film with a thickness of 2.0 to 7.5 μm formed on the surface of the frame base material, and and a formed transparent polymer electrodeposited coating. (frame base material) As the frame base material of the pellicle frame, a material capable of forming an anodized film can be used. Among them, it is preferable to use aluminum and aluminum alloys in terms of strength, rigidity, light weight, workability, cost, and the like. Aluminum allo