NITRIDE SEMICONDUCTOR WAFER

• US 20140061665A1
• Filed: 08/08/2013
• Published: 03/06/2014
• Est. Priority Date: 09/03/2012
• Status: Active Grant

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Hitachi Metals (Thailand) Ltd.
• Inventors: TSUCHIYA, Tadayoshi
• Granted Patent: US 9,070,619 B2
• Time in Patent Office: Days
• US Class Current: 257/76
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02507 Alternating layers, e.g. superlattice
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02579 P-type
• CPC Class Codes: H01L 21/02581 Transition metal or rare earth elements
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 29/1075 of field-effect transistors
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 29/205 in different semiconductor regions , e.g. heterojunctions
• CPC Class Codes: H01L 29/207 further characterised by the doping material H01L29/2006 takes precedence
• CPC Class Codes: H01L 29/7783 using III-V semiconductor material

Abstract

A nitride semiconductor wafer includes a substrate, and a buffer layer formed on the substrate and including an alternating layer of Al_xGa_1-xN (0≦x≦0.05) and Al_yGa_1-yN (0<y≦1 and x<y) layers. Only the Al_yGa_1-yN layer in the alternating layer is doped with an acceptor.

Claims

1. A nitride semiconductor wafer, comprising:

a substrate; and

a buffer layer formed on the substrate and comprising an alternating layer of an Al_xGa_1-xN (0≦

x≦

0.05) layer and an Al_yGa_1-yN (0<

y≦

1 and x<

y) layer,

wherein only the Al_yGa_1-yN layer of the alternating layer is doped with an acceptor.

2. The nitride semiconductor wafer according to claim 1, wherein a sheet concentration Ns of the acceptor in an uppermost Al_yGa_1-yN layer among the Al_yGa_1-yN layer of the alternating layer is not more than 2×

10¹³ cm<sup>−

2</sup>.

3. The nitride semiconductor wafer according to claim 2, wherein an Al composition y of the uppermost Al_yGa_1-yN layer is 0<

y≦

0.4, and

wherein the sheet concentration Ns is 5×

10¹³·

y<

Ns≦

2×

10¹³ cm<sup>−

2</sup>.

4. The nitride semiconductor wafer according to claim 1, wherein the acceptor comprises one of iron (Fe), carbon (C) and zinc (Zn).

5. The nitride semiconductor wafer according to claim 1, wherein an Al composition x of the Al_xGa_1-xN layer is x=0.

6. The nitride semiconductor wafer according to claim 1, wherein the Al composition y and the sheet concentration Ns per layer are each equal in the Al_yGa_1-yN layer of the alternating layer.

7. The nitride semiconductor wafer according to claim 1, wherein the Al_xGa_1-xN layer of the alternating layer is not doped with the acceptor.