Semiconductor light-emitting device and manufacturing method therefor, and LED lamp and LED display

• US 20030048822A1
• Filed: 09/12/2002
• Published: 03/13/2003
• Est. Priority Date: 09/13/2001
• 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, Ooyama, Shouichi, Murakami, Tetsuroh
• Granted Patent: US 6,794,688 B2
• Time in Patent Office: Days
• US Class Current: 372/43
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/145 with a current-blocking structure

Abstract

A semiconductor light-emitting device exhibits high reflectance even with less number of pairs of light-reflecting layers, and allows light emitted from the active layer to be effectively extracted outside. This semiconductor light-emitting device is fabricated at good mass productivity by a semiconductor light-emitting device manufacturing method including the step of providing an active layer which generates light having a specified wavelength on a semiconductor substrate. On the semiconductor substrate, are stacked an Al_xGa_1−xAs layer and the active layer, in this order. Part of the Al_xGa_1−xAs layer with respect to the is changed into an AlO_y layer (where y is a positive real number).

Claims

1. A semiconductor light-emitting device formed by stacking, on a semiconductor substrate, a plurality of layers including an active layer made of a semiconductor which generates light of a specified wavelength, the semiconductor light-emitting device comprising:

a first light-reflecting layer provided between the semiconductor substrate and the active layer and having a main reflecting part including a dielectric containing Al or space and a sub reflecting part made of a semiconductor layer containing Al.

2. The semiconductor light-emitting device according to claim 1, further comprising:

a second light-reflecting layer provided between the first light-reflecting layer and the active layer and formed by stacking a plurality of pairs of a low-refractive-index material layer and a high-refractive-index material layer.

3. The semiconductor light-emitting device according to claim 1, wherein

the semiconductor substrate is of a first conductive type;

a second-conductive-type current spreading layer is provided on the active layer;

the semiconductor light-emitting device further comprises a first-conductive-type current blocking layer provided at a specified region in-side the current spreading layer, and

an electrode layer provided on an top surface of the current spreading layer and at a region corresponding to the current blocking layer;

the sub reflecting part of the first light-reflecting layer is disposed at a region corresponding to the current blocking layer; and

the main reflecting part of the first light-reflecting layer is disposed at a region corresponding to a periphery of the current blocking layer.

4. The semiconductor light-emitting device according to claim 1, wherein

the sub reflecting part of the first light-reflecting layer is formed of any one kind of semiconductor selected from among Al_xGa₁₋

xAs, (Al_xGa<sub>1−

x</sub>)_vIn<sub>1−

v</sub>P, (Al_xGa<sub>1−

x</sub>)_vIn<sub>1−

v</sub>N, (Al_xGa<sub>1−

x</sub>)_vIn<sub>1−

v</sub>As, and (Al_xGa<sub>1−

x</sub>)_vIn<sub>1−

v</sub>Sb (where 0<

x≦

1 and 0<

v<

1), and

the main reflecting part of the first light-reflecting layer is formed of AlO_y (where y is a positive real number) or space.

5. The semiconductor light-emitting device according to claim 1, wherein

the sub reflecting part of the first light-reflecting layer is formed of any one kind of multilayer film selected from among a multilayer film in which Al_xGa₁₋

xAs layer and Al_zGa<sub>1−

z</sub>As layer are alternately stacked, a multilayer film in which (Al_xGa<sub>1−

x</sub>)_vIn<sub>1−

v</sub>P layer and (Al_zGa<sub>1−

z</sub>)_vIn<sub>1−

v</sub>P layer, alternately stacked, a multilayer film in which (Al_xGa<sub>1−

x</sub>)_vIn<sub>1−

v</sub>N layer and (Al_zGa<sub>1−

z</sub>)_vIn<sub>1−

v</sub>N layer alternately stacked, a multilayer film in which (Al_xGa<sub>1−

x</sub>)_vIn<sub>1−

v</sub>As layer and (Al_zGa<sub>1−

z</sub>)_vIn<sub>1−

v</sub>As layer are alternately stacked, and a multilayer film in which (Al_xGa<sub>1−

x</sub>)_vIn<sub>1−

v</sub>Sb layer and (Al_zGa<sub>1−

z</sub>)_vIn<sub>1−

v</sub>Sb layer are alternately stacked (where 0<

x<

z≦

1 and 0<

v<

1), and

the main reflecting part of the first light-reflecting layer is formed of a multilayer film in which any one kind of semiconductor selected from among Al_xGa<sub>1−

x</sub>As , (Al_xGa<sub>1−

x</sub>)_vIn<sub>1−

v</sub>P, (Al_xGa<sub>1−

x</sub>)_vIn<sub>1−

v</sub>N, (Al_xGa<sub>1−

x</sub>)_vIn<sub>1−

v</sub>As, and (Al_xGa<sub>1−

x</sub>)_vIn<sub>1−

v</sub>Sb (where 0<

x≦

1 and 0<

v<

1) in correspondence to the multilayer film forming the sub reflecting part, and AlO_y layer (where y is a positive real number) or a space layer, are alternately stacked.

11. An LED lamp which comprises the semiconductor light-emitting device as defined in claim 1.

12. The LED lamp according to claim 11, wherein

as said semiconductor light-emitting device, a plurality of semiconductor light-emitting devices having different wavelengths from each other are integrally provided, and the semiconductor light-emitting devices are connected in the manner that they can be applied with electric current independently from each other.

13. An LED display in which the LED lamp as defined in claim 12 is arrayed in a matrix.

6. A method for manufacturing a semiconductor light-emitting device by stacking, on a semiconductor substrate, a plurality of layers including an active layer made of a semiconductor which generates light of a specified wavelength, the method comprising the steps of:

providing, between the semiconductor substrate and the active layer, an Al rich layer higher in Al ratio than any other layer among the plurality of layers;

dividing into chips a wafer in which the plurality of layers are stacked, thereby making a side face of the Al rich layer exposed; and

oxidizing Al contained in the Al rich layer from the exposed side face, thereby making a peripheral portion of the Al rich layer changed into an AlO_y layer.

7. The method for manufacturing a semiconductor light-emitting device according to claim 6, wherein

the step of oxidizing Al contained in the Al rich layer is carried out by leaving in a water vapor the chips in which the side face of the Al rich layer is exposed.

8. The method for manufacturing a semiconductor light-emitting device according to claim 7, wherein

the water vapor is introduced to the side face of the Al rich layer by an inert gas that has been passed through boiling water.

9. The method for manufacturing a semiconductor light-emitting device according to claim 7, wherein

the step of oxidizing Al contained in the Al rich layer is carried out in an atmosphere having a temperature of 300°

C. to 400°

C.

10. The method for manufacturing a semiconductor light-emitting device according to claim 6, further comprising the step of:

removing, by etching, the AlO_y layer formed at the peripheral portion of the Al rich layer.