METHOD FOR PRODUCING A SEMICONDUCTOR DEVICE, AND SEMICONDUCTOR DEVICE PRODUCED THEREBY

• US 20150380498A1
• Filed: 09/09/2015
• Published: 12/31/2015
• Est. Priority Date: 08/27/2013
• Status: Abandoned Application

• Current Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Original Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Inventors: UENO, Katsunori, EDO, Masaharu, TANAKA, Ryo, TAKASHIMA, Shinya
• Application Number:
  US14/848,889
• Publication Number:
  US 20150380498A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/26546 of electrically active species
• CPC Class Codes: H01L 21/26553 Through-implantation
• CPC Class Codes: H01L 21/30612 Etching of AIIIBV compounds
• CPC Class Codes: H01L 21/30621 Vapour phase etching
• CPC Class Codes: H01L 21/324 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/20 - H01L21/288 and H01L21/302 - H01L21/322 take precedence
• CPC Class Codes: H01L 21/3245 of AIIIBV compounds
• 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 29/66712 Vertical DMOS transistors, i.e. VDMOS transistors
• CPC Class Codes: H01L 29/7802 Vertical DMOS transistors, i.e. VDMOS transistors

Abstract

A method for producing a semiconductor device having a nitride-based semiconductor layer includes forming a first nitride-based semiconductor layer of Al_xGa_1-xN on a base; forming a second nitride-based semiconductor layer of Al_yGa_1-yN on the first nitride-based semiconductor layer; forming a third nitride-based semiconductor layer of Al_zGa_1-zN on the second nitride-based semiconductor layer; introducing an impurity using ion implantation into the first, second, and third nitride-based semiconductor layers; and thermally treating, after ion implantation, the first, second, and third nitride-based semiconductor layers, wherein the first, second, and third nitride-based semiconductor layers have respective Al composition ratios x, y, and z, and the Al composition ratio y of the second nitride-based semiconductor layer is higher than the Al composition ratio x of the first nitride-based semiconductor layer, and higher than the Al composition ratio z of the third nitride-based semiconductor layer.

Claims

1. A method for producing a semiconductor device having a nitride-based semiconductor layer, the method comprising, in the order recited:

forming a first nitride-based semiconductor layer of Al_xGa_1-xN on a base;

forming a second nitride-based semiconductor layer of Al_yGa_1-yN on the first nitride-based semiconductor layer;

forming a third nitride-based semiconductor layer of Al_zGa_1-zN on the second nitride-based semiconductor layer;

introducing an impurity using ion implantation into the first nitride-based semiconductor layer, the second nitride-based semiconductor layer and the third nitride-based semiconductor layer; and

thermally treating, after ion implantation, the first nitride-based semiconductor layer, the second nitride-based semiconductor layer and the third nitride-based semiconductor layer,

wherein the first, second, and third nitride-based semiconductor layers have respective Al composition ratios x, y, and z, and the Al composition ratio y of the second nitride-based semiconductor layer is higher than the Al composition ratio x of the first nitride-based semiconductor layer, and higher than the Al composition ratio z of the third nitride-based semiconductor layer.

2. The method for producing a semiconductor device according to claim 1, wherein the first nitride-based semiconductor layer is Al_xGa_1-xN (0≦

x<

0.5).

3. The method for producing a semiconductor device according to claim 2, wherein the first nitride-based semiconductor layer is Al_xGa_1-xN (0≦

x<

0.2).

4. The method for producing a semiconductor device according to claim 1, wherein the second nitride-based semiconductor layer is Al_yGa_1-yN (0.5≦

y≦

1).

5. The method for producing a semiconductor device according to claim 4, wherein the second nitride-based semiconductor layer is Al_yGa_1-yN (0.8≦

y≦

1).

6. The method for producing a semiconductor device according to claim 1, wherein the third nitride-based semiconductor layer is Al_zGa_1-zN (0≦

z<

0.5).

7. The method for producing a semiconductor device according to claim 6, wherein the third nitride-based semiconductor layer is Al_zGa_1-zN (0≦

z<

0.2).

8. The method for producing a semiconductor device according to claim 1, wherein the base has a substrate formed of gallium nitride.

9. The method for producing a semiconductor device according to claim 1, wherein the third nitride-based semiconductor layer has a thickness that is greater than that of the second nitride-based semiconductor layer.

10. The method for producing a semiconductor device according to claim 1, wherein the second nitride-based semiconductor layer has a thickness and a room temperature critical thickness determined for a semiconductor device not having a third nitride-based semiconductor layer, and wherein the thickness of the second nitride-based semiconductor is greater than the room-temperature critical thickness of the second nitride-based semiconductor layer.

11. The method for producing a semiconductor device according to claim 1, wherein the third nitride-based semiconductor layer has a thickness that is 50 nm or greater.

12. The method for producing a semiconductor device according to claim 1, wherein forming the first nitride-based semiconductor layer, the second nitride-based semiconductor layer and the third nitride-based semiconductor layer is accomplished using metal-organic chemical vapor deposition.

13. The method for producing a semiconductor device according to claim 1, wherein the impurity introduced using ion implantation includes at least one element selected from the group consisting of magnesium, zinc and beryllium.

14. The method for producing a semiconductor device according to claim 1, wherein thermally treating takes place at a temperature ranging from 800°

C. to 2000°

C.

15. The method for producing a semiconductor device according to claim 1, further comprising removing, after thermally treating, at least part of the second nitride-based semiconductor layer and the third nitride-based semiconductor layer.

16. The method for producing a semiconductor device according to claim 15, wherein removing the second nitride-based semiconductor layer is accomplished by wet etching.

17. The method for producing a semiconductor device according to claim 16, wherein removing the third nitride-based semiconductor layer is accomplished by dry etching.

18. The method for producing a semiconductor device according to claim 15, wherein removing the third nitride-based semiconductor layer is accomplished by dry etching.

19. A semiconductor device, which is produced on the basis of the method for producing a semiconductor device according to claim 1.