Method of fabricating a semiconductor device with high heat conductivity

• US 5,538,919 A
• Filed: 05/18/1995
• Issued: 07/23/1996
• Est. Priority Date: 11/15/1993
• Status: Expired due to Term

• Current Assignee: II-VI Delaware, Inc. (Coherent Corp.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Davis, Ken, Shieh, Chan-Long, Lebby, Michael S.
• Primary Examiner(s): Breneman, R. Bruce
• Assistant Examiner(s): Fleck, Linda J.
• Application Number:
  US08/443,609
• Time in Patent Office: 432 Days
• Field of Search: 437/129, 148/DIG. 95
• US Class Current: 438/39
• CPC Class Codes: H01L 23/3732 Diamonds
• CPC Class Codes: H01L 23/5329 Insulating materials
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01S 2301/176 Specific passivation layers on surfaces other than the emission facet
• CPC Class Codes: H01S 5/02484 Sapphire or diamond heat spreaders
• CPC Class Codes: H01S 5/0282 Passivation layers or treatments
• CPC Class Codes: H01S 5/0422 with n- and p-contacts on the same side of the active layer
• CPC Class Codes: H01S 5/183 having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
• CPC Class Codes: Y10S 148/095 Laser devices

Abstract

A VCSEL having a first mirror stack positioned on the surface of a substrate, an active region positioned on the first mirror stack and substantially coextensive therewith, and a second mirror stack positioned on the active region, the second mirror stack forming a ridge or mesa having a side surface. A metal contact layer is positioned on the side surface of the ridge or mesa and on portions of an end of the ridge or mesa to define a light emitting area, and a layer of diamond-like material is electrolytically plated on the metal contact layer so as to form a heat conductor to remove heat from the laser.

Claims

1. A method of fabricating a vertical cavity surface emitting laser with high heat conductivity comprising the steps of:

providing a substrate;

forming a first mirror stack on the substrate, an active area on the first mirror stack and a second mirror stack on the active area, the second mirror stack being formed into a ridge or mesa having a side surface and an upper surface;

depositing a metal contact layer on portions of the side surface and the upper surface of the second mirror stack so as to form an ohmic contact with the second mirror stack; and

depositing a layer of diamond-like material having the characteristic of high heat conductivity on the upper and side surfaces of the mesa, including the metal layer, so as to form a heat conductor to remove heat from the laser.

2. A method of fabricating a vertical cavity surface emitting laser with high heat conductivity as claimed in claim 1 wherein the step of depositing a layer of diamond-like material includes plating the diamond-like material by electrolysis.

3. A method of fabricating a vertical cavity surface emitting laser with high heat conductivity as claimed in claim 2 wherein the step of plating the diamond-like material by electrolysis includes a plurality of alternate steps of electrolytically plating diamond-like material and metal.

4. A method of fabricating a vertical cavity surface emitting laser with high heat conductivity as claimed in claim 1 wherein the step of depositing a layer of diamond-like material includes planarizing the layer of diamond-like material over the end and side surfaces of the ridge or mesa of the laser.

5. A method of fabricating a vertical cavity surface emitting laser with high heat conductivity as claimed in claim 4 including in addition the step of forming electrical contacts at a planarized surface of the layer of diamond-like material.

6. A method of fabricating a vertical cavity surface emitting laser with high heat conductivity comprising the steps of:

providing a substrate;

forming a first mirror stack on the substrate, an active area on the first mirror stack and a second mirror stack on the active area, the second mirror stack having an upper surface;

depositing a first metal contact layer on the upper surface of the second mirror stack so as to form an ohmic contact with the second mirror stack;

depositing a layer of etchable material on the first metal contact layer and a layer of masking material on the layer of etchable material;

selectively removing portions of the layer of masking material, the layer of etchable material and the first metal contact layer to form an etch mask defining the ridge VCSEL;

etching the second mirror stack, using the etch mask, to form a ridge or mesa having a side surface;

removing portions of the layer of etchable material to expose a first portion of the first metal contact layer;

depositing a second metal contact layer on the side surface of the ridge or mesa and the exposed first portion of the first metal contact layer to define a light emitting area;

removing the layers of etchable and masking materials to expose a second portion of the first metal contact layer in the light emitting area;

removing the exposed second portion of the first metal contact layer to expose the light emitting area; and

depositing a layer of diamond-like material having the characteristic of high heat conductivity on the second metal layer.