Semiconductor light-emitting device and manufacturing method therefor

• US 20010020699A1
• Filed: 02/07/2001
• Published: 09/13/2001
• Est. Priority Date: 02/07/2000
• Status: Active Grant

• Current Assignee: Xiamen San'An Optoelectronics Co.Ltd. (Sanan Optoelectronics Company Limited)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Nakatsu, Hiroshi, Kurahashi, Takahisa, Ohyama, Shouichi, Murakami, Tetsurou, Hosoba, Hiroyuki
• Granted Patent: US 7,495,263 B2
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/30 containing only elements of Group III and Group V of the Periodic Table

Abstract

On a GaAs substrate (1), are formed a DBR (Distributed Bragg Reflector) (3), and a light-emitting layer (5) made of a plurality of layers of Al_yGa_zIn_1-y-zP (0≦y≦1, 0≦z≦1) above the DBR (3). A semiconductor layer or a plurality of semiconductor layers (6)-(10) having a number of layers of 1 or more are formed on the light-emitting layer (5), and a grating pattern for scattering light is formed on a surface of the semiconductor layer (9) by photolithography and by etching with a sulfuric acid/hydrogen peroxide based etchant. Thus, a semiconductor device small in radiation angle dependence of light emission wavelength, as well as a manufacturing method therefor, are provided.

Claims

1. A semiconductor light-emitting device having a DBR (Distributed Bragg Reflector) and a light-emitting layer formed on a GaAs substrate, the DBR being located between the GaAs substrate and the light-emitting layer, in which light directed from the light-emitting layer toward a top surface has a radiation angle dependence, the semiconductor light-emitting device further comprising:

a semiconductor layer having a number of layers of 1 or more is formed on the light-emitting layer, a top surface of the semiconductor layer being a roughened surface.

2. The semiconductor light-emitting device according to

claim 1

, wherein the light-emitting layer to be formed on the GaAs substrate is a single layer or a plurality of layers made of Al_yGa_zIn_1-y-zP (0≦

y≦

1, 0≦

z≦

1).

3. The semiconductor light-emitting device according to

claim 1

, wherein the semiconductor layer whose top surface is a roughened surface is made of Al_xGa_1-xAs (0≦

x≦

1).

4. The semiconductor light-emitting device according to

claim 3

, wherein the semiconductor layer made of Al_xGa_1-xAs (0≦

x≦

1) is transparent to an emission wavelength.

5. The semiconductor light-emitting device according to

claim 3

, wherein the semiconductor layer made of Al_xGa_1-xAs (0≦

x≦

1) has an Al mixed crystal ratio x of 0.5-0.8.

6. The semiconductor light-emitting device according to

claim 3

, further comprising an Al_yGa_zIn_1-y-zP (0≦

y≦

1, 0≦

z≦

1) layer for diffusing a current injected from an electrode provided on a light takeout side, the Al_yGa_zIn_1-y-zP layer being provided between the semiconductor layer made of Al_xGa_1-xAs (0≦

x≦

1) and the light-emitting layer.

7. The semiconductor light-emitting device according to

claim 1

, wherein the layer whose top surface is a roughened surface is made of Al_yGa_zIn_1-y-zP (0≦

y≦

1, 0≦

z≦

1).

8. The semiconductor light-emitting device according to

claim 7

, wherein the layer whose top surface is a roughened surface has a lattice constant different by 0.5% or more from that of the GaAs substrate.

9. A method for manufacturing a semiconductor light-emitting device having a DBR (Distributed Bragg Reflector) and a light-emitting layer formed on a GaAs substrate, the DBR being located between the GaAs substrate and the light-emitting layer, in which light directed from the light-emitting layer toward a top surface has a radiation angle dependence, the semiconductor light-emitting device manufacturing method comprising the steps of:

forming a semiconductor layer having a number of layers of 1 or more on the light-emitting layer; and

thereafter roughing a wafer surface.

10. The method for manufacturing a semiconductor light-emitting device according to

claim 9

, wherein the step of roughing the wafer surface includes a step of forming a pattern for scattering light onto the wafer surface by photolithography and etching.

11. The method for manufacturing a semiconductor light-emitting device according to

claim 9

, wherein the step of roughing the wafer surface includes a step of abrasion the wafer surface.

12. The method for manufacturing a semiconductor light-emitting device according to

claim 9

, wherein the step of forming the semiconductor layer having a number of layers of 1 or more on the light-emitting layer includes a step of forming a semiconductor layer including an Al_yGa_zIn_1-y-zP (0≦

y≦

1, 0≦

z≦

1) layer, and the step of roughing the wafer surface includes a step of boiling the wafer in hydrochloric acid.

14. The method for manufacturing a semiconductor light-emitting device according to

claim 9

, wherein the step of forming on the light-emitting layer a semiconductor layer having a number of layers of 1 or more includes a step of forming on the light-emitting layer a semiconductor layer including an Al_yGa_zIn_1-y-zP (0≦

y≦

1, 0≦

z≦

1) layer and an Al_xGa_1-xAs (0≦

x≦

1) layer, and the step of roughing the wafer surface includes a step of treating with dilute hydrofluoric acid or dilute nitric acid.

13. A method for manufacturing a semiconductor light-emitting device having a DBR (Distributed Bragg Reflector) and a light-emitting layer formed on a GaAs substrate, the DBR being located between the GaAs substrate and the light-emitting layer, in which light directed from the light-emitting layer toward a top surface has a radiation angle dependence, the semiconductor light-emitting device manufacturing method comprising the steps of:

forming on the light-emitting layer a semiconductor layer having a number of layers of 1 or more including an Al_yGa_zIn_1-y-zP (0≦

y≦

1, 0≦

z≦

1) layer having a lattice constant different by 0.5% or more from the GaAs substrate, thereby roughing a wafer surface.