SEMICONDUCTOR DEVICE AND METHOD OF MANUFACTURING THE SAME

• US 20120104408A1
• Filed: 08/12/2011
• Published: 05/03/2012
• Est. Priority Date: 11/02/2010
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: IMADA, Tadahiro
• Granted Patent: US 8,941,116 B2
• Time in Patent Office: Days
• US Class Current: 257/76
• CPC Class Codes: H01L 21/8252 the substrate being a semiconductor, using III-V technology H01L21/8258 takes precedence
• CPC Class Codes: H01L 27/0605 integrated circuits made of compound material, e.g. AIIIBV
• CPC Class Codes: H01L 29/1029 of field-effect transistors
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 29/66462 with a heterojunction interface channel or gate, e.g. HFET, HIGFET, SISFET, HJFET, HEMT
• CPC Class Codes: H01L 29/7787 with wide bandgap charge-carrier supplying layer, e.g. direct single heterostructure MODFET

Abstract

In an aspect of a semiconductor device, there are provided a substrate, a transistor including an electron transit layer and an electron supply layer formed over the substrate, a nitride semiconductor layer formed over the substrate and connected to a gate of the transistor, and a controller controlling electric charges moving in the nitride semiconductor layer.

Claims

1. A semiconductor device, comprising:

a substrate;

a transistor comprising an electron transit layer and an electron supply layer formed over the substrate;

a nitride semiconductor layer over the substrate and connected to a gate of the transistor; and

a controller controlling electric charges moving in the nitride semiconductor layer.

2. The semiconductor device according to claim 1, further comprising an n-type GaN layer formed between the electron supply layer and the nitride semiconductor layer.

3. The semiconductor device according to claim 1, further comprising an insulating layer insulating the transistor from the nitride semiconductor layer.

4. The semiconductor device according to claim 3, wherein the insulating layer comprises at least one selected from a group consisting of an AlN layer, an AlGaN layer, a p-type GaN layer, a Fe-doped GaN layer, a Si oxide layer, an Al oxide layer, a Si nitride layer, and a carbon layer.

5. The semiconductor device according to claim 1, wherein the controller comprises a signal line formed over the nitride semiconductor layer.

6. The semiconductor device according to claim 5, wherein the controller comprises a gate driver provided on the substrate and driving the signal line.

7. The semiconductor device according to claim 1, further comprising:

a first external terminal connected to the nitride semiconductor layer; and

a second external terminal connected to a portion of the nitride semiconductor layer located on a side of the gate opposite to a portion of the nitride semiconductor layer connected to the first external terminal and supplied with a voltage higher than a voltage to the first external terminal,

wherein the controller comprises;

a first signal line controlling a potential of the nitride semiconductor layer between the first external terminal and the gate; and

a second signal line controlling a potential of the nitride semiconductor layer between the second external terminal and the gate.

8. The semiconductor device according to claim 7, wherein the controller comprises a gate driver provided on the substrate and driving the first signal line and the second signal line.

9. The semiconductor device according to claim 1, wherein the nitride semiconductor layer comprises a second electron transit layer and a second electron supply layer stacked one on the other.

10. The semiconductor device according to claim 9, wherein

the second electron transit layer comprises a GaN layer, and

the second electron supply layer comprises an AlGaN layer.

11. The semiconductor device according to claim 5, wherein

the nitride semiconductor layer comprises a first region of a first conduction type, a second region of a second conduction type, and a third region of the first conduction type arranged in a direction of movement of the electric charges, and

the signal line is located on the second region.

12. The semiconductor device according to claim 7, wherein

the portion of the nitride semiconductor layer connected to the first external terminal comprises a first region of a first conduction type, a second region of a second conduction type, and a third region of the first conduction type arranged in a direction of movement of the electric charges,

the first signal line is located on the second region,

the portion of the nitride semiconductor layer connected to the second external terminal comprises a fourth region of the second conduction type, a fifth region of the first conduction type, and a sixth region of the second conduction type arranged in a direction of movement of the electric charges, and

the second signal line is located on the fifth region.

13. A method of manufacturing a semiconductor device, comprising:

forming a transistor over a substrate, the transistor comprising an electron transit layer and an electron supply layer;

forming a nitride semiconductor layer over the substrate, the nitride semiconductor layer being connected to a gate of the transistor; and

forming a controller controlling electric charges moving in the nitride semiconductor layer.

14. The method of manufacturing a semiconductor device according to claim 13, further comprising, between said forming the transistor and said forming the nitride semiconductor layer, forming an n-type GaN layer over the electron supply layer,

wherein the nitride semiconductor layer is formed on the n-type GaN layer.

15. The method of manufacturing a semiconductor device according to claim 13, further comprising forming an insulating layer insulating the transistor from the nitride semiconductor layer.

16. The method of manufacturing a semiconductor device according to claim 13, wherein said forming the controller comprises forming a signal line on the nitride semiconductor layer.

17. The method of manufacturing a semiconductor device according to claim 13, wherein said forming the controller comprises:

forming a first signal line controlling a potential of the nitride semiconductor layer between a first external terminal and the gate, the first external terminal being connected to the nitride semiconductor layer; and

forming a second signal line controlling a potential of the nitride semiconductor layer between a second external terminal and the gate, the second external terminal being connected to a portion of the nitride semiconductor layer located on a side of the gate opposite to a portion of the nitride semiconductor layer connected to the first external terminal, and supplied with a voltage higher than a voltage to the first external terminal.

18. The method of manufacturing a semiconductor device according to claim 13, wherein said forming the nitride semiconductor layer comprises forming a second electron transit layer and a second electron supply layer stacked one on the other.

19. The method of manufacturing a semiconductor device according to claim 18, wherein

a GaN layer is formed as the second electron transit layer, and

an AlGaN layer is formed as the second electron supply layer.

20. A power supply apparatus, comprising

a semiconductor device which comprises:

a substrate;

a transistor comprising an electron transit layer and an electron supply layer formed over the substrate;

a nitride semiconductor layer over the substrate and connected to a gate of the transistor; and

a controller controlling electric charges moving in the nitride semiconductor layer.