Nitride based hetero-junction field effect transistor

• US 7,400,001 B2
• Filed: 11/30/2004
• Issued: 07/15/2008
• Est. Priority Date: 09/08/2004
• Status: Expired due to Fees

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Lee, Jung Hee, Lee, Jae Hoon
• Primary Examiner(s): Landau; Matthew C
• Application Number:
  US10/998,942
• Publication Number:
  US 20060049426A1
• Time in Patent Office: 1,323 Days
• Field of Search: 257/194, 257/192, 257E29245-E29249, 257/E29.253, 257/E29.252
• US Class Current: 257/194
• CPC Class Codes: H01L 29/2003 Nitride compounds
• CPC Class Codes: H01L 29/7787 with wide bandgap charge-carrier supplying layer, e.g. direct single heterostructure MODFET

Abstract

A nitride based hetero-junction field effect transistor includes a high resistance nitride semiconductor layer formed on a substrate, an Al-doped GaN layer formed on the high resistance nitride semiconductor layer and having an Al content of 0.1˜1%, an undoped GaN layer formed on the Al-doped GaN layer, and an AlGaN layer formed on the undoped GaN layer such that a two-dimensional electron gas (2DEG) layer is formed at an interface of the undoped GaN layer.

Claims

1. A hetero-junction field effect transistor, comprising:

a high resistance nitride semiconductor layer formed on a substrate;

an Al-doped GaN layer formed on the high resistance nitride semiconductor layer and having an Al content of 0.3˜

0.6 mol %;

an undoped GaN layer formed on the Al-doped GaN layer; and

an AlGaN layer formed on the undoped GaN layer such that a two-dimensional electron gas (2DEG) layer is formed at an interface between the AlGaN layer and the undoped GaN layer;

wherein

the undoped GaN layer has a thickness of 0.1˜

1 μ

m; and

the Al-doped GaN layer has a thickness of 0.1˜

1 μ

m;

said hetero-junction field effect transistor further comprising at least one pair of another Al-doped GaN layer and another undoped GaN layer sequentially formed between the Al-doped GaN layer and the high resistance nitride semiconductor layer.

2. The hetero-junction field effect transistor as set forth in claim 1, wherein the high resistance nitride semiconductor layer is a semi-insulated GaN layer comprising a lower GaN layer having a first amount of crystal defects and an upper GaN layer having a second amount of crystal defects smaller than the first amount.

3. The hetero-junction field effect transistor as set forth in claim 1, wherein the Al doped in the Al-doped GaN layer is configured for passivation of Ga vacancies existing as defects in the undoped GaN layer, thereby restricting a growth of the Ga vacancies into two dimensional or three dimensional dislocations and enhancing crystallinity of the undoped GaN layer.

4. A hetero-junction field effect transistor, comprising:

a substrate;

a buffer layer formed on top the substrate;

a high resistance nitride semiconductor layer formed on top the buffer layer;

an Al-doped GaN layer formed on top the high resistance nitride semiconductor layer and having an Al content of 0.3˜

0.6 mol %;

an undoped GaN layer formed on top the Al-doped GaN layer; and

an AlGaN layer formed on top the undoped GaN layer such that a two-dimensional electron gas (2DEG) layer is formed at an interface between the AlGaN layer and the undoped GaN layer;

wherein

the high resistance nitride semiconductor layer is a semi-insulated GaN layer comprising a lower GaN layer having a first amount of crystal defects and an upper GaN layer having a second amount of crystal defects smaller than the first amount; and

the Al-doped GaN layer has a thickness of 0.1˜

1 μ

m.

5. The hetero-junction field effect transistor as set forth in claim 4, wherein the undoped GaN layer has a thickness of 0.1˜

1 μ

m.

6. The hetero-junction field effect transistor as set forth in claim 4, further comprising at least one pair of another Al-doped GaN layer and another undoped GaN layer sequentially formed between the Al-doped GaN layer and the high resistance nitride semiconductor layer.

7. The hetero-junction field effect transistor as set forth in claim 4, wherein the Al doped in the Al-doped GaN layer is configured for passivation of Ga vacancies existing as defects in the undoped GaN layer, thereby restricting a growth of the Ga vacancies into two dimensional or three dimensional dislocations and enhancing crystallinity of the undoped GaN layer.

8. A hetero-junction field effect transistor, comprising:

a substrate;

a buffer layer formed on top the substrate;

a high resistance nitride semiconductor layer formed on top the buffer layer;

an Al-doped GaN layer formed on top the high resistance nitride semiconductor layer and having an Al content of 0.3˜

0.6 mol %, the Al content being substantially uniform across the entire Al-doped GaN layer;

an undoped GaN layer formed on top the Al-doped GaN layer; and

an AlGaN layer formed on top the undoped GaN layer such that a two-dimensional electron gas (2DEG) layer is formed at an interface between the AlGaN layer and the undoped GaN layer;

wherein the Al-doped GaN layer has a thickness greater than 0.1 μ

m and lower than or equal to 1 μ

m;

said hetero-junction field effect transistor further comprising at least one pair of another Al-doped GaN layer and another undoped GaN layer sequentially formed between the Al-doped GaN layer and the high resistance nitride semiconductor layer.

9. The hetero-junction field effect transistor as set forth in claim 8, wherein the undoped GaN layer has a thickness of 0.1˜

1 μ

m.

10. The hetero-junction field effect transistor as set forth in claim 8, wherein the high resistance nitride semiconductor layer is a semi-insulated GaN layer comprising a lower GaN layer having a first amount of crystal defects and an upper GaN layer having a second amount of crystal defects smaller than the first amount.

11. The hetero-junction field effect transistor as set forth in claim 8, wherein the Al doped in the Al-doped GaN layer is configured for passivation of Ga vacancies existing as defects in the undoped GaN layer, thereby restricting a growth of the Ga vacancies into two dimensional or three dimensional dislocations and enhancing crystallinity of the undoped GaN layer.