Epitaxial substrate for electronic device comprising a high resistance single crystal substrate on a low resistance single crystal substrate, and method of manufacturing

Patent metadata

Field	Value
Publication number	US-8946863-B2
Application number	US-201013388804-A
Country	US
Kind code	B2
Filing date	Aug 2, 2010
Priority date	Aug 4, 2009
Publication date	Feb 3, 2015
Grant date	Feb 3, 2015

Abstract

An epitaxial substrate for electronic devices, in which current flows in a lateral direction and of which warpage configuration is properly controlled, and a method of producing the same. The epitaxial substrate for electronic devices is produced by forming a bonded substrate by bonding a low-resistance Si single crystal substrate and a high-resistance Si single crystal substrate together; forming a buffer as an insulating layer on a surface of the bonded substrate on the high-resistance Si single crystal substrate side; and producing an epitaxial substrate by epitaxially growing a plurality of III-nitride layers on the buffer to form a main laminate. The resistivity of the low-resistance Si single crystal substrate is 100 Ω·cm or less, and the resistivity of the high-resistance Si single crystal substrate is 1000 Ω·cm or more.

First claim

The invention claimed is:

1. A method of producing an epitaxial substrate for electronic devices, comprising the steps of:
forming a bonded substrate by bonding a low-resistance Si single crystal substrate and a high-resistance Si single crystal substrate together;
forming a buffer as an insulating layer on a surface of the bonded substrate on the high-resistance Si single crystal substrate side; and
producing an epitaxial substrate by epitaxially growing a plurality of III-nitride layers on the buffer to form a main laminate,
wherein a lateral direction is a current flow direction in the epitaxial substrate,
the resistivity of the low-resistance Si single crystal substrate is 100 Ω·cm or less,
the resistivity of the high-resistance Si single crystal substrate is 1000 Ω·cm or more,
an impurity element of the low-resistance Si single crystal substrate is boron, and
the high-resistance Si single crystal substrate has a thickness of more than 10 μm, and a thickness of the low-resistance Si single crystal substrate is ten times or more than the thickness of the high-resistance Si single crystal substrate.

2. The method of producing an epitaxial substrate for electronic devices according to claim 1 , wherein the step of forming the bonded substrate is performed by bonding the low-resistance Si single crystal substrate and the high-resistance Si single crystal substrate with a Si oxide film.

3. The method of producing an epitaxial substrate for electronic devices according to claim 1 , wherein the buffer layer comprises cyclically stacked first and second layers.

4. An epitaxial substrate for electronic devices, comprising:
a substrate having a low-resistance Si single crystal substrate, a high-resistance Si single crystal substrate arranged above the low-resistance Si single crystal substrate, and a Si oxide film provided between the low-resistance Si single crystal substrate and the high-resistance Si single crystal substrate;
a buffer as an insulating layer, arranged on the high-resistance Si single crystal substrate; and
a main laminate formed by epitaxially growing a plurality of III-nitride layers on the buffer,
wherein a lateral direction is a current flow direction in the epitaxial substrate,
the resistivity of the low-resistance Si single crystal substrate is 100 Ω·cm or less,
the resistivity of the high-resistance Si single crystal substrate is 1000 Ω·cm or more, and
an impurity element of the low-resistance Si single crystal substrate is boron, and
the high-resistance Si single crystal substrate has a thickness of more than 10 μm, and a thickness of the low-resistance Si single crystal substrate is ten times or more than the thickness of the high-resistance Si single crystal substrate.

5. The epitaxial substrate for electronic devices according to claim 4 , wherein the buffer has a superlattice structure or a graded composition structure.

6. The epitaxial substrate for electronic devices according to claim 4 , wherein the buffer has a C concentration of 1×10 18 atoms/cm 3 or more.

Assignees

• Ikuta Tetsuya
• Hino Daisuke
• Sakamoto Ryo
• Shibata Tomohiko
• Dowa Electronics Materials Co Ltd

Inventors

• Ikuta Tetsuya
• Hino Daisuke
• Sakamoto Ryo
• Shibata Tomohiko

Classifications

• H10P14/3416

  Nitrides · CPC title

• H10P14/3238

  being insulating materials · CPC title

• H10P14/2905

  Silicon, silicon germanium or germanium · CPC title

• H10P14/36

  characterised by treatments done before the formation of the materials · CPC title

• H10P10/128

  by direct semiconductor to semiconductor bonding · CPC title