Semiconductor light emitting device

• US 5,048,035 A
• Filed: 05/29/1990
• Issued: 09/10/1991
• Est. Priority Date: 05/31/1989
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nishikawa, Yukie, Ishikawa, Masayuki, Sugawara, Hideto, Naritsuka, Shigeya, Kokubun, Yoshihiro
• Primary Examiner(s): EPPS, GEORGIA Y
• Application Number:
  US07/530,120
• Time in Patent Office: 469 Days
• Field of Search: 372/45, 372/46, 357/16, 357/17
• US Class Current: 372/45.01
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 33/0025 comprising only AIIIBV compounds
• 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 33/145 with a current-blocking structure
• CPC Class Codes: H01L 33/30 containing only elements of Group III and Group V of the Periodic Table
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/387 with a plurality of electrode regions in direct contact with the semiconductor body and being electrically interconnected by another electrode layer

Abstract

A semiconductor light emitting device, especially, a light emitting diode includes a compound semiconductor substrate of a first conductivity type, an InGaAlP layer formed on the substrate and having a light emitting region, a GaAlAs layer of a second conductivity type formed on the InGaAlP layer and having a larger band gap than that of the InGaAlP layer, and an electrode formed on a part of the GaAlAs layer. The light emitting diode emits light from a surface at the electrode side except for the electrode. A current from the electrode is widely spread by the GaAlAs layer to widely spread a light emitting region.

Claims

1. In a semiconductor light emitting device comprising:

a compound semiconductor substrate of a first conductivity type;

an InGaAlP layer formed on said substrate and having a light emitting region;

a GaAlAs layer of a second conductivity type formed on said InGaAlP layer and having a larger band gap than that of said InGaAlP layer; and

an electrode formed on a part of said GaAlAs layer,

wherein light is emitted from a surface at the electrode side except for said electrode.

2. A device according to claim 1, wherein said GaAlAs layer has a composition of Ga_l-p AlpAs (0.45≦

p≦

1).

3. A device according to claim 1, wherein said InGaAlP layer is an active layer having a composition of In₀.5 (Ga_l-y Al_y)₀.5 P(0≦

y≦

1).

4. A device according to claim 3, wherein a lower clad layer of the first conductivity type having a composition of In₀.5 (Ga_l-x Al.sub.×

)₀.5 P(0≦

x×

≦

1) is formed between said substrate and said active layer, and an upper clad layer of the second conductivity type having a composition of In₀.5 (Ga_l-x Al_z)₀.5 P (0≦

z≦

1) is formed between said active layer and said InGaAlP layer, x, y, and z satisfying y≦

x and y≦

z.

5. A device according to claim 4, wherein said GaAlAs layer has a larger layer thickness than that of said upper clad layer.

6. A device according to claim 1, wherein said electrode consists essentially of AuZn.

7. A device according to claim 1, wherein a contact layer consisting essentially of GaAs of the second conductivity type is formed between said GaAlAs layer and said electrode.

8. In a semiconductor light emitting device comprising:

a compound semiconductor substrate of a first conductivity type;

a lower clad type layer formed on said substrate and consisting essentially of InGaAlP of the first conductivity type;

an active layer formed on said lower clad layer and consisting essentially of InGaAlP;

an upper clad layer formed on said active layer and consisting essentially of InGaAlP of a second conductivity type;

a GaAlAs layer of a second conductivity type formed on said upper clad layer and having a larger band gap than that of said InGaAlP layer constituting said active layer and;

an electrode formed on a part of said GaAlAs layer wherein light is emitted from a surface at said electrode side except for said electrode.

9. A device according to claim 8, wherein said GaAlAs layer has a larger layer thickness than that of said upper clad layer.

10. A device according to claim 8, wherein said GaAlAs layer has a composition of Ga_l-p Al_p As (0.45≦

1).

11. A device according to claim 8, wherein said active layer has a composition of In₀.5 (Ga_l-y Al_y)₀.5 P (0≦

y1).

12. A device according to claim 8, wherein said electrode consists essentially of AuZn.

13. A device according to claim 8, wherein a contact layer consisting essentially of GaAs of the second conductivity type is formed between said GaAlAs layer and said electrode.

14. A device according to claim 8, wherein said device is a light emitting diode.