Method for forming identification marks on refractory material single crystal substrate, and refractory material single crystal substrate

Patent metadata

Field	Value
Publication number	US-9508655-B2
Application number	US-201615063585-A
Country	US
Kind code	B2
Filing date	Mar 8, 2016
Priority date	Jul 10, 2012
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

An identification mark formation method for forming an identification mark on a refractory material single crystal substrate that is made of one selected from the group consisting of sapphire, gallium nitride, aluminum nitride, diamond, boron nitride, zinc oxide, gallium oxide, and titanium dioxide is disclosed. The method includes: (a) scanning a principal surface of the refractory material single crystal substrate with a laser beam at a first energy density such that a groove is formed in the principal surface of the refractory material single crystal substrate, thereby forming an identification mark in the principal surface of the refractory material single crystal substrate; and (b) scanning an inside of the groove of the refractory material single crystal substrate with a laser beam at a second energy density that is lower than the first energy density.

First claim

What is claimed is:

1. A refractory material single crystal substrate which has a first principal surface, a second principal surface, and an identification mark on the first principal surface, the identification mark being constituted of one or more grooves, and the refractory material single crystal substrate being made of a single crystal which is formed by one selected from the group consisting of sapphire, gallium nitride, aluminum nitride, diamond, boron nitride, zinc oxide, gallium oxide, and titanium dioxide,
wherein a width of the groove is not less than 50 μm and less than 0.5 mm, and a depth of the groove is not less than 10 μm, and
a surface roughness Ra of an internal surface of the groove is not more than 1 μm.

2. The refractory material single crystal substrate of claim 1 , wherein the surface roughness Ra of the first principal surface is not less than 0.1 nm and not more than 2.0 nm.

3. The refractory material single crystal substrate of claim 2 , wherein a bottom surface of the groove is a solidified surface.

4. The refractory material single crystal substrate of claim 3 , wherein the bottom surface of the groove has a striped pattern.

5. The refractory material single crystal substrate of claim 1 , wherein a bottom surface of the groove is a solidified surface.

6. The refractory material single crystal substrate of claim 5 , wherein the bottom surface of the groove has a striped pattern.

7. The refractory material single crystal substrate of claim 1 , wherein the surface roughness Ra of the second principal surface is not less than 0.1 nm and not more than 2.0 nm.

Assignees

• Hitachi Metals Ltd

Inventors

• Kondo Sadahiko

Classifications

• H10W46/501

  for use before dicing · CPC title

• H10W46/401

  for identification or tracking · CPC title

• H10W46/00 Primary

  Marks applied to devices, e.g. for alignment or identification · CPC title

• C30B29/36

  Carbides · CPC title

• C30B29/20

  Aluminium oxides · CPC title