Gallium-nitride-based semiconductor light emitting device and fabrication method

• US 6,365,921 B1
• Filed: 06/14/2000
• Issued: 04/02/2002
• Est. Priority Date: 06/15/1999
• Status: Expired due to Term

• Current Assignee: Showa Denko KK (Resonac Holdings Corp.)
• Original Assignee: Pioneer Corporation
• Inventors: Watanabe, Atsushi, Ota, Hiroyuki, Tanaka, Toshiyuki
• Primary Examiner(s): Fourson, George
• Assistant Examiner(s): PHAM, THANH V
• Application Number:
  US09/593,144
• Time in Patent Office: 657 Days
• Field of Search: 257/94, 257/96, 257/97, 257/200, 438/47
• US Class Current: 257/97
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/0243 Surface structure
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02494 Structure
• CPC Class Codes: H01L 21/02502 consisting of two layers
• 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 33/007 comprising nitride compounds

Abstract

A GaN-based semiconductor light emitting device is provided that has superior light emitting characteristics by controlling occurrence of a threading dislocation and keeping the flatness of a film GaN-based semiconductor light emitting device fabrication method comprises forming steps of at least forming an undoped gallium-nitride underlying layer on a low-temperature buffer layer while keeping the pressure in a reactor at a value close to atmospheric pressure.

Claims

1. A gallium-nitride-based semiconductor light emitting device comprising a structure in which a nitride semiconductor (Al_xGa₁₋

x)<sub>1−

y</sub>In_yN (0≦

x≦

1, 0≦

y≦

1) is formed on a substrate, wherein the device comprises;

a low-temperature buffer layer formed on the substrate;

an underlying layer; and

a GaN flattening layer containing a group IV element having a concentration in a range of 5×

10¹⁶ to 5×

10¹⁷ 1/cm³,

wherein the underlying layer is formed between the flattening layer and the low-temperature buffer layer.

2. A gallium-nitride-based semiconductor light emitting device according to claim 1, wherein the underlying layer has an average thickness of at least 0.3 μ

m.

3. The gallium-nitride-based semiconductor light emitting device according to claim 1, wherein the group IV element is silicon.

4. A gallium-nitride-based semiconductor light emitting device according to claim 3, wherein the underlying layer has an average thickness of at least 0.3 μ

m.

5. The gallium-nitride-based semiconductor light emitting device according to claim 3, wherein the flattening layer contain silicon having concentration in a range of 5×

10¹⁶ to 5×

10¹⁷ (1/cm³).

6. A gallium-nitride-based semiconductor light emitting device according to claim 5, wherein the underlying layer has an average thickness of at least 0.3 μ

m.

7. The gallium-nitride-based semiconductor light emitting device according to claim 1, wherein the group IV element is germanium.

8. A gallium-nitride-based semiconductor light emitting device according to claim 7, wherein the underlying layer has an average thickness of at least 0.3 μ

m.

9. The gallium-nitride-based semiconductor light emitting device according to claim 1, further comprising:

an n-type semiconductor layer formed on said flattening layer.

10. The gallium-nitride-based semiconductor light emitting device according to claim 1, wherein the nitride semiconductor (Al_xGa₁₋

x)<sub>1−

y</sub>In_yN (0≦

x≦

1, 0≦

y≦

1) is formed on the flattening layer.

11. A gallium-nitride-based semiconductor light emitting device, comprising:

a substrate;

a low-temperature buffer layer which is formed on said substrate;

an underlying layer which is formed on said low-temperature buffer layer;

a GaN flattening layer containing a group IV element having a concentration in a range of 5×

10¹⁶ to 5×

10¹⁷ 1/cm³; and

a n-type layer which is formed on said flattening layer.

12. The gallium-nitride-based semiconductor light emitting device according to claim 11, wherein said low-temperature buffer layer comprises gallium and nitride.

13. The gallium-nitride-based semiconductor light emitting device according to claim 11, wherein said low-temperature buffer layer comprises aluminum and nitride.

14. The gallium-nitride-based semiconductor light emitting device according to claim 11, wherein said underlying layer comprises gallium and nitride.

15. The gallium-nitride-based semiconductor light emitting device according to claim 11, wherein said flattening layer is Si-doped gallium nitride.

16. The gallium-nitride-based semiconductor light emitting device according to claim 11, wherein said flattening layer contains silicon having a concentration in a range of 5×

10¹⁶ to 5×

10¹⁷ (1/cm³).

17. The gallium-nitride-based semiconductor light emitting device according to claim 11, wherein said n-type layer contains silicon having a concentration more than 1×

10¹⁸ (1/cm³).