Compound semiconductor device and method with high concentration dopant layer in regrown compound semiconductor

Patent metadata

Field	Value
Publication number	US-10804358-B2
Application number	US-201816193796-A
Country	US
Kind code	B2
Filing date	Nov 16, 2018
Priority date	Dec 20, 2017
Publication date	Oct 13, 2020
Grant date	Oct 13, 2020

Abstract

A compound semiconductor device includes: a compound semiconductor area in which a compound semiconductor plug is embedded and formed; and an ohmic electrode provided on the compound semiconductor plug, wherein the compound semiconductor plug includes, in a side surface portion that is as an interface with the compound semiconductor area, a high concentration dopant layer containing a dopant whose concentration is higher than that of other portions.

First claim

What is claimed is:

1. A compound semiconductor device comprising:
a compound semiconductor area in which a compound semiconductor plug is embedded and formed; and
an ohmic electrode provided on the compound semiconductor plug,
the compound semiconductor plug includes, in a side surface portion that is as an interface with the compound semiconductor area, a high concentration dopant layer containing a dopant whose concentration is higher than a concentration of a dopant of other portions in the compound semiconductor plug, and
the concentration of the dopant of the high concentration dopant layer is greater than or equal to 1×10 20 /cm 3 .

2. The compound semiconductor device according to claim 1 , wherein an upper portion of the high concentration dopant layer protrudes from the side surface portion toward inside of the compound semiconductor area.

3. The compound semiconductor device according to claim 1 , wherein a bottom portion of the high concentration dopant layer protrudes from the side surface portion toward inside of the compound semiconductor plug.

4. The compound semiconductor device according to claim 1 , wherein the concentration of the dopant of the high concentration dopant layer is greater than or equal to 1×10 21 /cm 3 .

5. The compound semiconductor device according to claim 1 , wherein the concentration of the dopant of the high concentration dopant layer is greater than or equal to 1×10 22 /cm 3 .

6. The compound semiconductor device according to claim 1 , wherein, in the compound semiconductor plug, the high concentration dopant layer is formed integrally with said other portions in the compound semiconductor plug.

7. The compound semiconductor device according to claim 1 , wherein the high concentration dopant layer contains a dopant that is not contained in said other portions in the compound semiconductor plug.

8. The compound semiconductor device according to claim 1
wherein the compound semiconductor area includes an electron supply layer, and
wherein the electron supply layer contains one type of compound selected from InAIGaN, InAlN, AlGaN, and AIN.

9. A method for producing a compound semiconductor device, the method comprising:
embedding and forming, in a compound semiconductor area, a compound semiconductor plug including, in a side surface portion that is as an interface with the compound semiconductor area, a high concentration dopant layer containing a dopant whose concentration is higher than a concentration of a dopant of other portions in the compound semiconductor plug; and
forming an ohmic electrode on the compound semiconductor plug,
the concentration of the dopant of the high concentration dopant layer is greater than or equal to 1×10 20 /cm 3 .

10. The method for producing the compound semiconductor device according to claim 9 , the method further comprising:
forming a silicon insulation film on the compound semiconductor area before forming the compound semiconductor plug,
wherein the compound semiconductor plug is formed such that the silicon insulation film contacts the high concentration dopant layer.

11. The method for producing the compound semiconductor device according to claim 10 , wherein the silicon insulation film has a refractive index of 2.05 or more with respect to light having a wavelength of 633 nm.

12. The method for producing the compound semiconductor device according to claim 9 , wherein an upper portion of the high concentration dopant layer protrudes from the side surface portion toward inside of the compound semiconductor area.

13. The method for producing the compound semiconductor device according to claim 9 , wherein a bottom portion of the high concentration dopant layer protrudes from the side surface portion toward inside of the compound semiconductor plug.

14. The method for producing the compound semiconductor device according to claim 9 , wherein the concentration of the dopant of the high concentration dopant layer is greater than or equal to 1×10 21 /cm 3 .

15. The method for producing the compound semiconductor device according to claim 9 , wherein the concentration of the dopant of the high concentration dopant layer is greater than or equal to 1×10 22 /cm 3 .

16. The method for producing the compound semiconductor device according to claim 9 , wherein, in the compound semiconductor plug, the high concentration dopant layer is formed integrally with said other portions in the compound semiconductor plug.

17. The method for producing the compound semiconductor device according to claim 9 , wherein the high concentration dopant layer contains a dopant that is not contained in said other portions in the compound semiconductor plug.

18. The method for producing the compound semiconductor device according to claim 9 ,
wherein the compound semiconductor area includes an electron supply layer, and
wherein the electron supply layer contains one type of compound selected from InAIGaN, InAlN, AlGaN, and AIN.

Assignees

• Fujitsu Ltd

Inventors

• Makiyama Kozo
• Minoura Yuichi

Classifications

• H10P50/695

  characterised by the process involved to create the mask, e.g. lift-off masks or sidewalls or to modify the mask · CPC title

• H10P50/692

  characterised by their composition, e.g. multilayer masks or materials · CPC title

• H10P50/283

  by chemical means · CPC title

• H10P50/242

  of Group IV materials · CPC title

• H10P14/3416

  Nitrides · CPC title