Method for producing crystal substrate

Patent metadata

Field	Value
Publication number	US-10325793-B2
Application number	US-201715600937-A
Country	US
Kind code	B2
Filing date	May 22, 2017
Priority date	May 27, 2016
Publication date	Jun 18, 2019
Grant date	Jun 18, 2019

Abstract

A method for producing a crystal substrate includes preparing, measuring, holding, and machining. The preparing prepares a crystal substrate body including a curved crystal lattice plane. The measuring measures a shape feature of the crystal lattice plane. The holding holds the crystal substrate body in a warped state in accordance with the shape feature measured by the measuring, to more flatten the crystal lattice plane than the crystal lattice plane at the preparing. The machining machines a surface of the crystal substrate body held in the warped state, to flatten the surface.

First claim

What is claimed is:

1. A method for producing a crystal substrate, the method comprising:
(a) preparing a crystal substrate body including a curved crystal lattice plane;
(b) measuring a shape feature of the crystal lattice plane;
(c) sticking a back surface of the crystal substrate body to a convex or concave abutting surface and holding the crystal substrate body in a warped state to the convex or concave abutting surface in accordance with the shape feature measured in (b), to more flatten the crystal lattice plane than the crystal lattice plane prepared in (a); and
(d) machining a front surface of the crystal substrate body held in the warped state, to flatten the front surface.

2. The method according to claim 1 , wherein a distribution of an off-angle formed by the front surface of the crystal substrate body prepared in (a) and the crystal lattice plane has one extreme value.

3. The method according to claim 1 , wherein the machining in (d) further comprises machining the back surface of the crystal substrate body to be parallel to the front surface.

4. The method according to claim 1 , wherein a thickness of a work-affected layer of a portion machined in (d) is 1 μm or less.

5. The method according to claim 1 , wherein the crystal substrate body is a single crystal substrate of group 13 nitride.

6. The method according to claim 1 , wherein a shape similarity of the crystal lattice plane and the front surface of the crystal substrate body upon the machining in (d) is greater than that of the crystal lattice plane and the front surface in (a).

7. The method according to claim 1 , wherein the crystal lattice plane is internal to the crystal substrate body.

8. A method for producing a crystal substrate, the method comprising:
(aa) preparing a crystal substrate body including a curved crystal lattice plane;
(bb) sticking a back surface of the crystal substrate body to a convex or concave abutting surface in accordance with a shape feature of the curved crystal lattice plane, to more flatten the crystal lattice plane than the crystal lattice plane of the crystal substrate body prepared in (aa); and
(cc) machining a front surface of the crystal substrate body held in a warped state, to flatten the front surface.

9. The method according to claim 8 , wherein a distribution of an off-angle formed by the front surface of the crystal substrate body prepared in (aa) and the crystal lattice plane has one extreme value.

10. The method according to claim 8 , wherein the machining in (cc) further comprises machining the back surface of the crystal substrate body to be parallel to the front surface.

11. The method according to claim 8 , wherein a thickness of a work-affected layer of a portion machined in (cc) is 1 μm or less.

12. The method according to claim 8 , wherein the crystal substrate body is a single crystal substrate of group 13 nitride.

13. The method according to claim 8 , wherein a shape similarity of the crystal lattice plane and the front surface of the crystal substrate body upon the machining in (cc) is greater than that of the crystal lattice plane and the front surface in (aa).

14. The method according to claim 8 , wherein the crystal lattice plane is internal to the crystal substrate body.

15. The method according to claim 8 , further comprising:
(b1) measuring a shape feature of the crystal lattice plane of one crystal substrate body; and
(b2) performing (aa), (bb) and (cc) for each of one or more other crystal substrate bodies, in which the convex or concave abutting surface employed in (bb) for said each of one or more other crystal substrate bodies corresponds to the shape feature measured in (b1) from the one crystal substrate body.

Assignees

• Sciocs Co Ltd

Inventors

• Hayashi Masahiro
• Kimura Chiharu

Classifications

• H10P72/7416

  used during dicing or grinding · CPC title

• H10P72/7611 Primary

  characterised by edge profile or support profile · CPC title

• H10P72/7402

  Wafer tapes, e.g. grinding or dicing support tapes · CPC title

• H10P72/1902

  specially adapted for a single substrate · CPC title

• H10P72/74

  using temporarily an auxiliary support · CPC title