Semiconductor light emitting device

• US 6,479,836 B1
• Filed: 08/18/2000
• Issued: 11/12/2002
• Est. Priority Date: 08/19/1999
• Status: Expired due to Term

• Current Assignee: Seoul Semiconductor Co., Ltd.
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Sugawara, Hideto, Suzuki, Nobuhiro
• Primary Examiner(s): CRANE, SARA W
• Application Number:
  US09/641,215
• Time in Patent Office: 816 Days
• Field of Search: 257/15, 257/21, 257/85, 257/94, 257/96, 257/97, 257/99, 257/103, 257/744, 257/745
• US Class Current: 257/15
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 33/04 with a quantum effect structure or superlattice, e.g. tunnel junction
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/14 with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser

Abstract

According to the invention, there is provided a semiconductor light emitting device comprising: a contact layer formed of a nitride semiconductor; and a p-side electrode provided in contact with a surface of the contact layer, the contact layer having a superlattice including an alternative stacked structure of first nitride semiconductor layers having a wider bandgap and second nitride semiconductor layers having a narrower bandgap, the first semiconductor layers being selectively doped with a p-type dopant.

Claims

1. A semiconductor light emitting device comprising:

a contact layer formed of a nitride semiconductor; and

a p-side electrode provided in contact with a surface of said contact layer,

said contact layer having an alternatively stacked structure of first nitride semiconductor layers having a wider bandgap and second nitride semiconductor layers having a narrower bandgap, said first semiconductor layers being selectively doped with a p-type dopant.

2. The semiconductor light emitting device according to claim 1, wherein said first nitride semiconductor layers are formed of BGaAlN and said second nitride semiconductor layers are formed of GaAlN.

3. The semiconductor light emitting device according to claim 1, wherein said first nitride semiconductor layers are formed of InGaAlN and said second nitride semiconductor layers are formed of InGaAlN.

4. The semiconductor light emitting device according to claim 1, wherein said first nitride semiconductor layers are formed of InGaAlN and said second nitride semiconductor layers are formed of InGaN.

5. The semiconductor light emitting device according to claim 1, wherein said first nitride semiconductor layers are formed of GaN and said second nitride semiconductor layers are formed of InGaN.

6. The semiconductor light emitting device according to claim 5, wherein a content of indium among group III elements in said InGaN is larger than 0% and smaller than 20%.

7. The semiconductor light emitting device according to claim 1, wherein said first nitride semiconductor layers are formed of GaAlN and said second nitride semiconductor layers are formed of GaN.

8. The semiconductor light emitting device according to claim 7, wherein a content of aluminum among group III elements in said GaAlN is larger than 0% and smaller than 20%.

9. The semiconductor light emitting device according to claim 1, wherein said first nitride semiconductor layers are formed of In_xGa₁₋

xN and said second nitride semiconductor layers are formed of In_yGa<sub>1−

y</sub>N (x<

y).

10. The semiconductor light emitting device according to claim 1, wherein said first nitride semiconductor layers are formed of GaAlN and said second nitride semiconductor layers are formed of InGaN.

11. The semiconductor light emitting device according to claim 1, wherein a hardness of said first nitride semiconductor layers is higher than a hardness of said second nitride semiconductor layers.

12. The semiconductor light emitting device according to claim 1, wherein said p-type dopant is a element selected from a group consisting of magnesium, zinc and carbon.

13. The semiconductor light emitting device according to claim 1, wherein said p-type dopant is magnesium and its concentration is higher than 1×

10¹⁹ cm<sup>−

3</sup> and lower than 1×

10²¹ cm <sup>−

3</sup>.

14. The semiconductor light emitting device according to claim 1, wherein said p-side electrode includes oxide material.

15. A semiconductor light emitting device comprising:

a contact layer formed of a nitride semiconductor; and

a p-side electrode provided in contact with a surface of said contact layer,

said contact layer having an alternatively stacked structure of first nitride semiconductor layers having a higher hardness and second nitride semiconductor layers having a lower hardness, said first semiconductor layers being selectively doped with a p-type dopant.

16. The semiconductor light emitting device according to claim 15, wherein said second nitride semiconductor layers include higher content of indium than said first nitride semiconductor layers.

17. The semiconductor light emitting device according to claim 16, wherein said content of indium among group III elements in said second nitride semiconductor layers is larger than 0% and smaller than 20%.

18. A semiconductor light emitting device comprising:

a contact layer formed of a nitride semiconductor; and

a p-side electrode provided in contact with a surface

of said contact layer,

said contact layer having an alternatively stacked structure of first nitride semiconductor layers and second nitride semiconductor layers, said second nitride semiconductor layers including a higher content of indium than said first nitride semiconductor layers.

19. The semiconductor light emitting device according to claim 18, wherein said content of indium among group III elements in said second nitride semiconductor layers is larger than 0% and smaller than 20%.

20. The semiconductor light emitting device according to claim 18, wherein said first nitride semiconductor layers include higher content of aluminum than said second nitride semiconductor.