Claims
- 1. A method of manufacturing a semiconductor laser device for oscillating visible light, comprising the steps of:
- (a) forming a double-heterostructure disposed on a semiconductive substrate having a first conductivity type by semiconductor crystal growth, said double-heterostructure including
- a semiconductive active layer, and
- first and second cladding layers sandwiching said active layer and having different conductivity types, said first cladding layer consisting of a semiconductive material having the first conductivity type, said second cladding layer consisting of a semiconductive material having a second conductivity type;
- (b) forming by crystal growth a semiconductive layer on said second cladding layer;
- (c) forming by crystal growth a semiconductive current-blocking layer of the first conductivity type having an elongated opening; and
- (d) forming by crystal growth a semiconductive contact layer of the second conductivity type so as to cover said current-blocking layer and said opening, the improvement wherein
- a selected impurity is supplied in a crystal growth furnace from a timing prior to crystal growth of said contact layer, so that the impurity is at least locally doped in said semiconductive layer to increase a carrier concentration thereof, and wherein
- said contact layer is formed by crystal growth after a furnace temperature is increased to a crystal growth temperature of said contact layer, which is lower than a temperature in crystal growth of said double-heterostructure.
- 2. The method according to claim 1, wherein the impurity is flowed in the furnace together with phosphine, and is flowed in the furnace together with arsine when said contact layer is formed.
- 3. The method according to claim 2, wherein the impurity is substantially constantly flowed in the furnace.
- 4. The method according to claim 2, wherein the impurity includes zinc.
- 5. The method according to claim 2, wherein said semiconductive layer has an intermediate band gap between band gaps of said second cladding layer and said contact layer.
- 6. The method according to claim 5, wherein upon diffusion of the impurity into said intermediate band-gap layer, said intermediate band-gap layer has a carrier concentration, in a first region defining said opening, substantially high enough to cause a current injected in an oscillation mode of said device to concentrate on said region, and has a carrier concentration, in a second region as the remaining portion, low enough to suppress or prevent the injected current from spreading into said second region.
- 7. The method according to claim 2, wherein said double-heterostructure is etched together with said semiconductive layer to form a mesa stripe, which has side end portions bonded to said current-blocking layer.
Priority Claims (3)
Number |
Date |
Country |
Kind |
63-26490 |
Feb 1988 |
JPX |
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63-116704 |
May 1988 |
JPX |
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63-172312 |
Jul 1988 |
JPX |
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Parent Case Info
This is a division of application Ser. No. 07/307,927, filed on Feb. 9, 1989, Pat. No. 4,922,499.
US Referenced Citations (9)
Foreign Referenced Citations (4)
Number |
Date |
Country |
0066891 |
Apr 1985 |
JPX |
0137088 |
Jul 1985 |
JPX |
62-16592 |
Jan 1987 |
JPX |
62-200784 |
Sep 1987 |
JPX |
Non-Patent Literature Citations (1)
Entry |
Yamashita et al., "GaAlAs Gain-Guided Semiconductor Lasers . . . ", Appl. phys. Lett., vol. 51, No. 21, Nov. 23, 1987, pp. 1667-1669. |
Divisions (1)
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Number |
Date |
Country |
Parent |
307927 |
Feb 1989 |
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