Nitride crystal, nitride crystal substrate, epilayer-containing nitride crystal substrate, semiconductor device and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-9570540-B2
Application number	US-201414455781-A
Country	US
Kind code	B2
Filing date	Aug 8, 2014
Priority date	Jun 23, 2005
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

A nitride crystal is characterized in that, in connection with plane spacing of arbitrary specific parallel crystal lattice planes of the nitride crystal obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a surface of the crystal while X-ray diffraction conditions of the specific parallel crystal lattice planes are satisfied, a uniform distortion at a surface layer of the crystal represented by a value of |d 1 −d 2 |/d 2 obtained from the plane spacing d 1 at the X-ray penetration depth of 0.3 μm and the plane spacing d 2 at the X-ray penetration depth of 5 μm is equal to or lower than 2.1×10 −3 . The above configuration provides the nitride crystal having a crystal surface layer that is evaluated directly and reliably without breaking the crystal so that it can be used in a preferred fashion as a substrate for a semiconductor device as well as the nitride crystal substrate, an epilayer-containing nitride crystal substrate, a semiconductor device and a method of manufacturing the same.

First claim

What is claimed is:

1. An n-type nitride crystal, wherein,
in connection with plane spacing of arbitrary specific parallel crystal lattice planes of the nitride crystal obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a surface of said crystal while X-ray diffraction conditions of said specific parallel crystal lattice planes being satisfied, a uniform distortion at a surface layer of said crystal represented by a value of |d 1 −d 2 |/d 2 obtained from said plane spacing d 1 at said X-ray penetration depth of 0.3 μm and said plane spacing d 2 at the X-ray penetration depth of 5 μm is equal to or lower than 2.1×10 −3 .

2. An n-type nitride crystal, wherein,
on a diffraction intensity profile of arbitrary specific parallel crystal lattice planes of the nitride crystal obtained from X-ray diffraction measurement performed with variation of X-ray penetration depth from a surface of said crystal while X-ray diffraction conditions of said specific parallel crystal lattice planes being satisfied, an irregular distortion at a surface layer of said crystal represented by a value of |v 1 −v 2 | obtained from a half value width v 1 of a diffraction intensity peak at said X-ray penetration depth of 0.3 μm and a half value width v 2 of the diffraction intensity peak at said X-ray penetration depth of 5 μm is equal to or lower than 150 arcsec.

3. An n-type nitride crystal, wherein,
on a rocking curve measured by varying an X-ray penetration depth from a surface of the nitride crystal in connection with X-ray diffraction of arbitrary specific parallel crystal lattice planes of said crystal, a plane orientation deviation of said specific parallel crystal lattice planes represented by a value of |w 1 −w 2 | obtained from a half value width w 1 of a diffraction intensity peak at said X-ray penetration depth of 0.3 μm and a half value width w 2 of the diffraction intensity peak at said X-ray penetration depth of 5 μm is equal to or lower than 400 arcsec.

4. The n-type nitride crystal according to claim 2 , wherein
said surface of said crystal has a surface roughness Ry of 30 nm or lower.

5. The n-type nitride crystal according to claim 2 , wherein
said surface of said crystal has a surface roughness Ra of 3 nm or lower.

6. The n-type nitride crystal according to claim 2 , wherein
said surface of said nitride crystal is parallel to a C-plane of a wurtzite structure.

7. The n-type nitride crystal according to claim 2 , wherein
said surface of said nitride crystal has an off angle in a range from 0.05° to 15° with respect to a C-plane of a wurtzite structure.

8. A Si-doped nitride crystal substrate formed of the n-type nitride crystal according to claim 2 , wherein said n-type nitride crystal is an Si-doped nitride crystal.

Assignees

• Sumitomo Electric Industries

Inventors

• Ishibashi Keiji
• Kaji Tokiko
• Nakahata Seiji
• Nishiura Takayuki

Classifications

• H10P74/203

  Structural properties, e.g. testing or measuring thicknesses, line widths, warpage, bond strengths or physical defects · CPC title

• H10P14/3416

  Nitrides · CPC title

• H10P14/2926

  Crystal orientations · CPC title

• H10P14/2908

  Nitrides · CPC title

• H10D62/8503

  Nitride Group III-V materials, e.g. AlN or GaN · CPC title