Method of forming nitride based semiconductor layer

• US 6,319,742 B1
• Filed: 07/27/1999
• Issued: 11/20/2001
• Est. Priority Date: 07/29/1998
• Status: Expired due to Term

• Current Assignee: Epistar Corporation (Ennostar, Inc.)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Kano, Takashi, Hayashi, Nobuhiko
• Primary Examiner(s): Bowers, Charles
• Assistant Examiner(s): CHRISTIANSON, KEITH ALAN
• Application Number:
  US09/361,246
• Time in Patent Office: 847 Days
• Field of Search: 438/22, 438/39, 438/41, 438/42, 438/44, 438/46, 117/952
• US Class Current: 438/46
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/31608 Deposition of SiO2 H01L21/31625, H01L21/31629 and H01L21/31633 take precedence
• CPC Class Codes: H01L 33/007 comprising nitride compounds
• CPC Class Codes: H01S 2304/12 Pendeo epitaxial lateral overgrowth [ELOG], e.g. for growing GaN based blue laser diodes
• CPC Class Codes: H01S 5/0216 using an intermediate compound, e.g. a glue or solder
• CPC Class Codes: H01S 5/0217 Removal of the substrate
• CPC Class Codes: H01S 5/32341 blue laser based on GaN or GaP

Abstract

A GaN layer is grown on a sapphire substrate, an SiO₂ film is formed on the GaN layer, and a GaN semiconductor layer including an MQW active layer is then grown on the GaN layer and the SiO₂ film using epitaxial lateral overgrowth. The GaN based semiconductor layer is removed by etching except in a region on the SiO₂ film, and a p electrode is then formed on the top surface of the GaN based semiconductor layer on the SiO₂ film, to join the p electrode on the GaN based semiconductor layer to an ohmic electrode on a GaAs substrate. An n electrode is formed on the top surface of the GaN based semiconductor layer.

Claims

1. A method of fabricating a semiconductor device, comprising the steps of:

forming a first nitride based semiconductor layer containing at least one of boron, gallium, aluminum and indium on an insulating substrate;

forming an insulating film in a region on said first nitride based semiconductor layer;

forming a second nitride based semiconductor layer containing at least one of boron, gallium, aluminum and indium using epitaxial lateral overgrowth on said first nitride based semiconductor layer and said insulating film;

removing said second nitride based semiconductor layer except in a region on said insulating film;

joining the top surface of said second nitride based semiconductor layer on said insulating film to one surface of a gallium arsenide substrate through a first electrode layer;

removing said insulating film, to remove said insulating substrate and said nitride based semiconductor layer from said second nitride based semiconductor layer; and

forming a second electrode layer on said second nitride based semiconductor layer.

2. The method according to claim 1, wherein

the step of forming said second nitride based semiconductor layer comprises the step of forming an active layer.

3. The method according to claim 2, wherein

the step of forming said second nitride based semiconductor layer further comprises the step of forming a striped current injection region for injecting a current into said active layer along a <

1{overscore (1)}00>

direction of said second nitride based semiconductor layer, and

the step of joining the top surface of said second nitride based semiconductor layer to one surface of the gallium arsenide substrate through the first electrode layer comprises the step of matching the <

1{overscore (1)}00>

direction of said second nitride based semiconductor layer with a <

110>

direction or a <

1{overscore (1)}0>

direction of said gallium arsenide substrate,

said fabricating method further comprising

the step of forming a pair of cavity facets by cleavage along a {110} plane or a {1{overscore (1)}0} plane of said gallium arsenide substrate and a {1{overscore (1)}00} plane of said second nitride based semiconductor layer.

4. A method of forming a nitride based semiconductor layer, comprising the steps of:

forming a first nitride based semiconductor layer containing at least one of boron, gallium, aluminum and indium on an insulating substrate;

forming a pattern including a recess having a bottom surface formed of an insulator and a projection having a top surface formed of an insulator in said first nitride based semiconductor layer so that said first nitride based semiconductor layer is exposed on the side surface between said bottom surface of said recess and said top surface of said projection; and

forming a second nitride based semiconductor layer containing at least one of boron, gallium, aluminum and indium on said insulators by growth from said first nitride based semiconductor layer exposed on the side surface of said pattern using epitaxial lateral overgrowth.

5. The method according to claim 4, wherein the step of forming said pattern comprises the steps of

forming said pattern such that said first nitride based semiconductor layer is exposed to the bottom surface of said recess, and

forming an insulating film as said insulator on the bottom surface of the recess of said pattern and forming an insulating film as said insulator on the top surface of the projection of said pattern.

6. The method according to claim 4, wherein the step of forming said pattern comprises the step of

forming an insulating film as said insulator in a region on said first nitride based semiconductor layer where the projection of said pattern is to be formed and removing said first nitride based semiconductor such that said insulating substrate is exposed as said insulator except in a region on said insulating film.

7. The method according to claim 4, wherein said irregular pattern has a striped recess and a striped projection which extend along a <

11{overscore (2)}0>

direction of said first nitride based semiconductor layer.

8. The method according to claim 4, wherein a cross-sectional shape of the projection of said pattern is a rectangular shape or a reversed mesa shape having vertical side surfaces.

9. A method of fabricating a semiconductor device, comprising the steps of:

forming a first nitride based semiconductor layer containing at least one of boron, gallium, aluminum and indium on an insulating substrate,

forming a plurality of striped insulating films a distance away from each other on said first nitride based semiconductor layer; and

forming a second nitride based semiconductor layer containing at least one of boron, gallium, aluminum and indium using epitaxial lateral overgrowth on said first nitride based semiconductor layer and said plurality of striped insulating films, to form an active region of the device above said plurality of striped insulating films.