Semiconductor device and method of manufacturing the same

• US 8,941,116 B2
• Filed: 08/12/2011
• Issued: 01/27/2015
• Est. Priority Date: 11/02/2010
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Imada, Tadahiro
• Primary Examiner(s): Tran, Minh-Loan
• Assistant Examiner(s): Erdem, Fazli
• Application Number:
  US13/208,779
• Publication Number:
  US 20120104408A1
• Time in Patent Office: 1,264 Days
• Field of Search: None
• 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 a gate electrode, an electron transit layer and an electron supply layer formed over the substrate;

an insulating film formed over the electron supply layer, the gate electrode comprising a portion over the insulating film;

a nitride semiconductor layer over the insulating film;

a first electrode and a second electrode formed over the nitride semiconductor layer, the gate electrode being located between the first electrode and the second electrode in planar view;

a first signal line formed over the nitride semiconductor layer between the first electrode and the gate electrode in planar view; and

a second signal line formed over the nitride semiconductor layer between the second electrode and the gate electrode in planar view.

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, wherein an insulating layer that is the insulating film comprises at least one selected from the group consisting of an MN 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.

4. The semiconductor device according to claim 1, further comprising a gate driver provided on the substrate and driving the first signal line and the second signal line.

5. 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.

6. The semiconductor device according to claim 5, wherein

the second electron transit layer comprises a GaN layer, and

the second electron supply layer comprises an AlGaN layer.

7. The semiconductor device according to claim 1, wherein

a portion of the nitride semiconductor layer between the gate electrode and the first electrode 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,

a portion of the nitride semiconductor layer between the gate electrode and the second electrode 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.

8. A power supply apparatus, comprising

a semiconductor device which comprises:

a substrate;

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

an insulating film formed over the electron supply layer, the gate electrode comprising a portion over the insulating film;

a nitride semiconductor layer over the insulating film;

a first electrode and a second electrode formed over the nitride semiconductor layer, the gate electrode being located between the first electrode and the second electrode in planar view;

a first signal line formed over the nitride semiconductor layer between the first electrode and the gate electrode in planar view; and

a second signal line formed over the nitride semiconductor layer between the second electrode and the gate electrode in planar view.

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

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

forming an insulating film over the electron supply layer, the gate electrode comprising a portion over the insulating film;

forming a nitride semiconductor layer over the insulating film;

forming a first electrode and a second electrode over the nitride semiconductor layer, the gate electrode being located between the first electrode and the second electrode in planar view;

forming a first signal line over the nitride semiconductor layer between the first electrode and the gate electrode in planar view; and

forming a second signal line over the nitride semiconductor layer between the second electrode and the gate electrode in planar view.

10. The method of manufacturing a semiconductor device according to claim 9, 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.

11. The method of manufacturing a semiconductor device according to claim 9, 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.

12. The method of manufacturing a semiconductor device according to claim 11, wherein

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

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