Method of manufacturing an optoelectronic semiconductor device

• US 5,300,452 A
• Filed: 10/27/1992
• Issued: 04/05/1994
• Est. Priority Date: 12/18/1991
• Status: Expired due to Fees

• Current Assignee: Uniphase Opto Holdings Inc.
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Chang, Chang V. J. M., Rijpers, Johannes C. N.
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): Paladugu, Ramamohan Rao
• Application Number:
  US07/966,797
• Time in Patent Office: 525 Days
• Field of Search: 437/133, 437/228, 437/126, 148/DIG. 51, 156/646, 156/652, 156/655
• US Class Current: 438/39
• CPC Class Codes: H01L 21/30621 Vapour phase etching
• CPC Class Codes: H01L 33/0062 for devices with an active region comprising only III-V compounds

Abstract

A method of manufacturing an optoelectronic semiconductor device whereby a surface (1) of a semiconductor (2) built up from a number of layers of semiconductor material (4, 5, 6, 7) grown epitaxially on a semiconductor substrate (3), with a top layer (4) of GaAs adjoining the surface (1) and a subjacent layer (5) comprising InP, in particular made of (Al_x Ga_1-x)_y In_1-y P with 0.5<x<0.8 and 0.4<y<0.6, is provided with an etching mask (8), after which the top layer (4) and the subjacent layer (5) are locally etched in a plasma generated in a gas mixture comprising SiCl₄ and Ar. According to the invention, CH₄ is added to the gas mixture in which the plasma is generated. This measure leads to the creation of a smooth surface during etching of both layers, and in particular during etching of the layer comprising InP. The walls (10) of the ridge (9) formed in the layers are also smooth and steep.

Claims

1. A method of manufacturing an optoelectronic semiconductor device whereby a surface of a semiconductor body, which is built up from a number of semiconductor material layers epitaxially grown on a semiconductor substrate with a top layer of GaAs adjoining the surface and a subjacent layer comprising InP, is provided with an etching mask, after which the top layer and the subjacent layer are locally etched away in a plasma which is generated in a gas mixture comprising SiCl₄ and Ar, characterized in that CH₄ is added to the gas mixture in which the plasma is generated.

2. A method as claimed in claim 1, characterized in that the layer comprising InP is formed by a layer of (Al_x Ga_1-x)_y In_1-y P, with 0.5<

x<

0.8 and 0.4<

y<

0.6.

3. A method as claimed in claim 2, characterized in that 10 to 40 vol. % CH₄ is added to the gas mixture in which the plasma is generated.

4. A method as claimed in claim 3, characterized in that the plasma is generated in a gas mixture with i vol. % SiCl₄, j vol. % CH₄ and 100-i-j vol. % Ar, in which i=25 to 30 and j=20 to 25.

5. A method as claimed in claim 1, characterized in that the semiconductor body is heated to a temperature of between 100°

and 150°

C. during etching.

6. A method as claimed in claim 2 wherein the semiconductor body is heated to a temperature of between 100°

and 150°

C. during etching.

7. A method as claimed in claim 3 wherein the semiconductor body is heated to a temperature of between 100°

and 150°

C. during etching.

8. A method as claimed in claim 4 wherein the semiconductor body is heated to a temperature of between 100°

and 150°

C. during etching.