Method for performing activation of dopants in a GaN-base semiconductor layer by successive implantations and heat treatments

Patent metadata

Field	Value
Publication number	US-9536741-B2
Application number	US-201514846376-A
Country	US
Kind code	B2
Filing date	Sep 4, 2015
Priority date	Sep 26, 2014
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

The method for performing activation of n-type or p-type dopants in a GaN-base semiconductor includes the following steps: providing a substrate including a GaN-base semiconductor material layer, performing the following successive steps at least twice: implanting electric dopant impurities in the semiconductor material layer, performing heat treatment so as to activate the electric dopant impurities in the semiconductor material layer, a cap layer covering the semiconductor material layer when the heat treatment is performed, two implantation steps of electric dopant impurities being separated by a heat treatment step.

First claim

The invention claimed is:

1. A method for performing activation of n-type or p-type dopants in a GaN-base semiconductor layer comprises the following steps:
providing a substrate comprising a GaN-base semiconductor material layer,
performing the following successive steps at least twice:
implanting electric dopant impurities in the semiconductor material layer,
performing heat treatment so as to activate the electric dopant impurities in the semiconductor material layer, a cap layer covering the semiconductor material layer when the heat treatment is performed,

wherein at least one of the heat treatment steps is performed at atmospheric pressure at a temperature from 1100° C. to 1300° C. for a period of 1 to 7 hours, and
wherein the cap layer remains uncovered during the heat treatment.

2. The dopant activation method according to claim 1 , wherein the cap layer is removed after at least one of the heat treatments, and a second cap layer is then deposited on the semiconductor material layer before the next heat treatment.

3. The dopant activation method according to claim 2 , wherein the thickness of at least one of the cap layer and the second cap layer is comprised between 5 and 500 nm.

4. The dopant activation method according to claim 1 , wherein at least one of the cap layer and the second cap layer is used for several successive heat treatments, and wherein its thickness is comprised between 5 and 500 nm.

5. The dopant activation method according to claim 1 , wherein the material of at least one of the cap layer and the second cap layer is selected from the group consisting of SiO 2 , Si 3 N 4 , and AlN.

6. The dopant activation method according to claim 1 , wherein, at each implantation step, an intermediate dose greater than 10% of the total dose to be implanted is implanted.

7. The dopant activation method according to claim 1 , wherein at least one of the implantation steps is performed at a temperature comprised between 15 and 700° C.

8. The dopant activation method according to claim 1 , wherein, at each new implantation step, the electric dopant impurities are implanted at a different depth from that obtained when the previous implantation steps were performed.

9. The dopant activation method according to claim 1 , wherein at least one of the heat treatment steps is performed in a controlled atmosphere at a pressure of less than 15 kbar, at a temperature comprised between 1000° C. and 1600° C. for a period of 1 to 20 minutes.

10. The dopant activation method according to claim 1 , wherein at least one of the heat treatment steps is a combination of at least two anneals of different durations and temperatures.

11. The dopant activation method according to claim 1 , wherein the electric dopant impurities are selected from the group consisting of Mg, P, N, Ca, Zn, and C to form a p-type doping.

12. The dopant activation method according to claim 1 , wherein the electric dopant impurities are selected from the group consisting of Si, Be, Ge, and O to form an n-type doping.

13. A method for performing activation of n-type or p-type dopants in a GaN-base semiconductor layer comprises the following steps:
providing a substrate comprising a GaN-base semiconductor material layer,
performing the following successive steps at least twice:
implanting electric dopant impurities in the semiconductor material layer,
performing heat treatment so as to activate the electric dopant impurities in the semiconductor material layer, a cap layer covering the semiconductor material layer when the heat treatment is performed,

wherein the cap layer is removed after at least one of the heat treatments, and a second cap layer is then deposited on the semiconductor material layer before the next heat treatment.

14. The dopant activation method according to claim 13 , wherein the thickness of at least one of the cap layer and the second cap layer is comprised between 5 and 500 nm.

15. The dopant activation method according to claim 13 , wherein the material of at least one of the cap layer and the second cap layer is selected from the group consisting of SiO 2 , Si 3 N 4 , and AlN.

16. The dopant activation method according to claim 13 , wherein at least one of the heat treatment steps is a combination of at least two anneals of different durations and temperatures.

17. A method for performing activation of n-type or p-type dopants in a GaN-base semiconductor layer comprises the following steps:
providing a substrate comprising a GaN-base semiconductor material layer,
performing the following successive steps at least twice:
implanting electric dopant impurities in the semiconductor material layer,
performing heat treatment so as to activate the electric dopant impurities in the semiconductor material layer, a cap layer covering the semiconductor material layer when the heat treatment is performed,

wherein, at each new implantation step, the electric dopant impurities are implanted at a different depth from that obtained when the previous implantation steps were performed.

18. The dopant activation method according to claim 17 , wherein the cap layer is removed after at least one of the heat treatments, and a second cap layer is then deposited on the semiconductor material layer before the next heat treatment.

19. The dopant activation method according to claim 17 , wherein, at each implantation step, an intermediate dose greater than 10% of the total dose to be implanted is implanted.

20. The dopant activation method according to claim 17 , wherein at least one of the heat treatment steps is a combination of at least two anneals of different durations and temperatures.

Assignees

• Commissariat À L' Énergie Atomique Et Aux Énergies Alternatives
• Commissariat à l'Energie Atomique et aux Energies Alternatives

Inventors

• Agraffeil Claire

Classifications

• H10P95/904 Primary

  of Group III-V semiconductors · CPC title

• H10P95/90

  Thermal treatments, e.g. annealing or sintering · CPC title

• H10P30/212

  Through-implantation · CPC title

• H10P30/206

  into Group III-V semiconductors · CPC title

• H10D62/8503

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