# US 8,785,308 B2 · Method for manufacturing semiconductor base material

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- Number: US 8,785,308 B2
- Document ID: US8785308B2
- Status: Granted
- Kind: B2
- Application number: 13/824,038
- Filed: 2011-09-12
- Published: 2013-07-11
- Granted: 2014-07-22
- Earliest claimed: 2010-09-17
- Assignees: Sharp Kabushiki Kaisha
- Applicants: Shinji Uenishi
- Inventors: Shinji Uenishi
- Web page: https://patentgrep.com/patent/US8785308B2

## CPC

- H10H 20/85: Packages
- C30B 25/186: {being specially pre-treated by, e.g. chemical or physical means}
- C30B 29/406: {Gallium nitride}
- G03F 7/2016: {Contact mask being integral part of the photosensitive element and subject to destructive removal during post-exposure processing}
- H10H 20/01335: {the light-emitting regions comprising nitride materials}
- H10P 14/271: {characterised by the preparation of substrate for selective deposition}
- H10P 14/276: {Lateral overgrowth}
- H10P 14/3416: {Nitrides}
- H10H 20/819: characterised by their shape, e.g. curved or truncated substrates
- H10H: INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
- C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR
- G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G)
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

In forming an etching mask for forming a repetitive concave-convex pattern on a surface of a substrate of a semiconductor base material by exposure development of a resist film, the present invention prevents a development pattern from being deformed due to excessive exposure on a part where exposure regions are adjacent to each other in the resist film by repetitive exposure. In a method for manufacturing a semiconductor base material, when forming an etching mask for forming a concave-convex portion on a surface of the semiconductor base material, by a photolithography process of the resist film, a transfer mask is used, as a transfer mask 100, which is obtained by previously correcting the size of a dotted light shielding section 104 which is an exposure pattern near a region on which exposure shots overlap.

## Claims

### Claim 1

A method for manufacturing a semiconductor base material by processing a substrate so that a surface of the substrate has a concave-convex structure, and epitaxially growing a semiconductor layer above the substrate so that the concave-convex structure is buried, the method comprising:
a step of forming a resist mask on the surface of the substrate by a photolithography process; and
a step of selectively etching the substrate using the resist mask to form the concave-convex structure on the surface of the substrate,
wherein the step of forming the resist mask comprises an exposure step of repeatedly performing a process of transferring an exposure pattern formed on a transfer mask, onto a resist film formed on the substrate, for each exposure region corresponding to the transfer mask, and
wherein the transfer mask is obtained by correcting the size of a light shielding pattern positioned in a corresponding manner near a multiple exposure section where the exposure of light to adjacent exposure regions overlap with each other on the resist film, based on an increase in an exposure amount due to multiple exposure.

### Claim 2 (depends on 1)

A method for manufacturing a semiconductor base material according to claim 1, wherein the step of epitaxially growing the semiconductor layer on the substrate comprises a step of selectively growing a semiconductor layer on the substrate in a lateral direction so that the concave-convex structure of the substrate is buried.

### Claim 3 (depends on 1)

A method for manufacturing a semiconductor base material according to claim 1, wherein the process of etching the substrate is a dry etching process.

### Claim 4 (depends on 1)

A method for manufacturing a semiconductor base material according to claim 1, wherein the resist film formed on the substrate is formed by applying a positive type photoresist to the substrate.

### Claim 5 (depends on 1)

A method for manufacturing a semiconductor base material according to claim 1, wherein the exposure is UV exposure.

### Claim 6 (depends on 1)

A method for manufacturing a semiconductor base material according to claim 1, wherein a reduced projection type exposure apparatus, equipped with a step and repeat function in a stage on which the substrate is placed, is used for the UV exposure, and the step and repeat function is to move the substrate placed on the stage by a distance corresponding to each exposure region to transfer a light shielding pattern of the transfer mask to each exposure region.

### Claim 7 (depends on 1)

A method for manufacturing a semiconductor base material according to claim 1, wherein a correction amount for correcting the size of the light shielding pattern is determined by calculating the size of a resist pattern corresponding to the light shielding pattern, after the photolithography processing, and with an integrated dose energy of exposure light in the multiple exposure section as a parameter.

### Claim 8 (depends on 7)

A method for manufacturing a semiconductor base material according to claim 7,
wherein the transfer mask comprises a transparent substrate and a light shielding film having a predetermined open pattern, the light shielding film being formed on the transparent substrate, and
wherein the light shielding pattern is a planar pattern of the light shielding film.

### Claim 9 (depends on 8)

A method for manufacturing a semiconductor base material according to claim 8, wherein the light shielding pattern of the light shielding film formed on the transfer mask is a dotted light shielding pattern.

### Claim 10 (depends on 9)

A method for manufacturing a semiconductor base material according to claim 9,
wherein the dotted light shielding pattern corresponding to an uncorrected light shielding pattern on the transfer mask, has a planar and circular shape of a diameter ranging from 0.5 μm to 10 μm, and
wherein the dotted light shielding pattern corresponding to a corrected light shielding pattern on the transfer mask, is positioned at a peripheral portion of the transfer mask, and has a shape in which the planar and circular shape of the diameter ranging from 0.5 μm to 10 μm is extended toward the outside the transfer mask.

### Claim 11 (depends on 7)

A method for manufacturing a semiconductor base material according to claim 7, wherein the light shielding pattern of the light shielding film formed on the transfer mask is a striped light shielding pattern.

### Claim 12 (depends on 11)

A method for manufacturing a semiconductor base material according to claim 11,
wherein the striped light shielding pattern corresponding to an uncorrected light shielding pattern on the transfer mask, has a planar belt-like shape with a stripe width ranging from 0.5 μm to 10 μm, and
wherein the striped light shielding pattern corresponding to a corrected light shielding pattern on the transfer mask, is positioned at a peripheral portion of the transfer mask, and has a shape in which the planar belt-like shape with a stripe width ranging from 0.5 μm to 10 μm is extended toward the outside of the transfer mask.