Nitride semiconductor device

• US 7,365,369 B2
• Filed: 07/27/1998
• Issued: 04/29/2008
• Est. Priority Date: 07/25/1997
• Status: Expired due to Fees

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Tanizawa, Koji, Mitani, Tomotsugu, Mukai, Takashi, Marui, Hiroshi, Nakamura, Shuji
• Primary Examiner(s): JACKSON JR, JEROME
• Application Number:
  US09/463,643
• Publication Number:
  US 20030010993A1
• Time in Patent Office: 3,564 Days
• Field of Search: 257/12, 257/13, 257/14, 257/15, 257/22, 257/28, 257/94, 257/96, 257/97, 257/101, 257/102, 257/607, 257/609, 257/615
• US Class Current: 257/97
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/325 characterised by the doping materials
• CPC Class Codes: H01S 5/0421 characterised by the semiconducting contacting layers electrodes H01S5/0425

Abstract

A nitride semiconductor device used chiefly as an LD and an LED element. In order to improve the output and to decrease Vf, the device is given either a three-layer structure in which a nitride semiconductor layer doped with n-type impurities serving as an n-type contact layer where an n-electrode is formed is sandwiched between undoped nitride semiconductor layers; or a superlattice structure of nitride. The n-type contact layer has a carrier concentration exceeding 3×10¹⁰ cm³, and the resistivity can be lowered below 8×10⁻³Ωcm.

Claims

1. A nitride semiconductor light emitting device comprising:

a substrate,

a first nitride semiconductor layer being undoped and being a single layer,

a second nitride semiconductor layer having an n-type electrode and being a single layer,

a third nitride semiconductor layer being a super lattice layer of GaN layers, and

a separate and distinct active layer where electrons and holes are combined.

2. The nitride semiconductor light emitting device according to claim 1;

wherein said second nitride semiconductor layer is made of GaN or AlGaN and said second nitride semiconductor layer includes Si as an n-type impurity.

3. The nitride semiconductor light emitting device according to claim 1;

wherein said first nitride semiconductor layer is made of GaN or AlGaN.

4. The nitride semiconductor light emitting device according to claim 1;

wherein said second nitride semiconductor layer has an carrier concentration more than 3×

10¹⁸/cm³.

5. The nitride semiconductor light emitting device according to claim 1;

wherein said second nitride semiconductor layer has a resistivity less than 8×

10<sup>−

3</sup> ohm·

cm.

6. The nitride semiconductor light emitting device according to claim 1;

further comprising a buffer layer between said substrate and said first nitride semiconductor layer.

7. The nitride semiconductor light emitting device according to claim 1;

wherein said first nitride semiconductor layer has a thickness within a range of from 0.1 to 20 μ

m.

8. The nitride semiconductor light emitting device according to claim 1;

wherein said second nitride semiconductor layer has a thickness within a range of from 0.1 to 20 μ

m.

9. The nitride semiconductor light emitting device according to claim 1;

wherein said third nitride semiconductor layer being a super lattice layer of undoped GaN layers and Si doped GaN layers.

10. The nitride semiconductor light emitting device according to claim 9;

wherein said Si doped GaN layers are doped with Si to 1×

10¹⁹/cm³.

11. The nitride semiconductor light emitting device according to claim 9;

wherein said undoped GaN layers have a thickness of 75 Å and

Si doped GaN layers have a thickness of 25 Å

.

12. The nitride semiconductor light emitting device according to claim 9;

wherein said third nitride semiconductor layer has a thickness of 600 Å

.