Semiconductor laser manufacturing method

Claim 1

A method of manufacturing a semiconductor laser comprising: successively growing a semiconductor first cladding layer of the first conductivity type, a semiconductor active layer, a semiconductor third cladding layer of a second conductivity type opposite the first conductivity type, and a semiconductor cap layer of the first conductivity type on a semiconductor substrate of a first conductivity type; diffusing a dopant producing the second conductivity type into said cap layer except at portions where each of two opposed facets of the semiconductor layer will be formed, thereby converting the cap layer in the diffused portion to the second conductivity type; removing portions of said third cladding layer and said cap layer to leave a mesa including portions of said third cladding layer and said cap layer projecting from a remaining portion of said third cladding layer; heating said substrate, first cladding layer, active layer, and mesa to diffuse the dopant from said cap layer through said mesa and into said active and third cladding layers adjacent said mesa; growing a semiconductor first conductivity type current blocking layer on said third cladding layer abutting said mesa; successively growing a semiconductor fourth cladding layer of the second conductivity type and a semiconductor contacting layer of the second conductivity type on said current blocking and cap layers; depositing first and second electrodes on said substrate and said contacting layer, respectively; and forming a pair of generally parallel opposed facets generally transverse to said first and second electrodes and spaced from the portions of said cap layer into which the dopant was diffused.

Claim 2

A method of manufacturing a semiconductor laser comprising: successively growing a semiconductor first cladding layer of the first conductivity type, a semiconductor active layer, a semiconductor third cladding layer of a second conductivity type opposite the first conductivity type, and a semiconductor cap layer of the first conductivity type on a semiconductor substrate of a first conductivity type; diffusing a dopant producing the second conductivity type into said cap layer except at portions where each of two opposed facets of the semiconductor layer will be formed, thereby converting the cap layer in the diffused portion to the second conductivity type; removing portions of said third cladding layer and said cap layer to leave a mesa including portions of said third cladding layer and said cap layer projecting from a remaining portion of said third cladding layer; heating said substrate, first cladding layer, active layer, and mesa to diffuse the dopant from said cap layer through said mesa and into said active and third cladding layers adjacent said mesa; growing a semiconductor first conductivity type current blocking layer on said third cladding layer abutting said mesa; successively growing a semiconductor fourth cladding layer of the second conductivity type and a semiconductor contacting layer of the second conductivity type on said current blocking and cap layers; depositing first and second electrodes on said substrate and said contacting layer, respectively; and forming a pair of generally parallel opposed facets generally transverse to said first and second electrodes and spaced from the portions of said cap layer into which the dopant was diffused.

Claim 8

A method of manufacturing a semiconductor laser comprising: successively growing a semiconductor first cladding layer of the first conductivity type, a semiconductor active layer, a semiconductor second cladding layer of the first conductivity type, a semiconductor third cladding layer of a second conductivity type opposite the first conductivity type, and a semiconductor current blocking layer of the first conductivity type on a semiconductor substrate of a first conductivity type; forming a diffusion mask including a central opening on said current blocking layer, said mask covering portions of the semiconductor layers proximate the locations where facets of said laser will be formed; diffusing a dopant producing the second conductivity type through the opening in said diffusion mask into said current blocking layer; heating said substrate, first cladding layer, active layer, second and third cladding layers, and current blocking layer to diffuse the dopant from said third cladding layer through the second cladding layer and into said active layer; removing the diffusion mask and depositing on said current blocking layer an etching mask having a central opening extending to the locations where the facets of said semiconductor laser will be formed and aligned with the location of the opening of the diffusion mask; removing the portion of the current blocking layer not covered by the etching mask by etching; removing the etching mask; successively growing a semiconductor fourth cladding layer of the second conductivity type and a semiconductor contacting layer of the second conductivity type on said current blocking layer and on said third cladding layer where a portion of current blocking layer was removed; depositing first and second electrodes on said substrate and said contacting layer, respectively; and forming a pair of generally parallel opposed facets generally transverse to said first and second electrodes spaced from the portions of said second cladding layer into which the dopant was diffused.

Claim 9

A method of manufacturing a semiconductor laser comprising: successively growing a semiconductor first cladding layer of the first conductivity type, a semiconductor active layer, a semiconductor second cladding layer of the first conductivity type, a semiconductor third cladding layer of a second conductivity type opposite the first conductivity type, and a semiconductor current blocking layer of the first conductivity type on a semiconductor substrate of a first conductivity type; forming a diffusion mask including a central opening on said current blocking layer, said mask covering portions of the semiconductor layers proximate the locations where facets of said laser will be formed; diffusing a dopant producing the second conductivity type through the opening in said diffusion mask into said current blocking layer; heating said substrate, first cladding layer, active layer, second and third cladding layers, and current blocking layer to diffuse the dopant from said third cladding layer through the second cladding layer and into said active layer; removing the diffusion mask and depositing on said current blocking layer an etching mask having a central opening extending to the locations where the facets of said semiconductor laser will be formed and aligned with the location of the opening of the diffusion mask; removing the portion of the current blocking layer not covered by the etching mask by etching; removing the etching mask; successively growing a semiconductor fourth cladding layer of the second conductivity type and a semiconductor contacting layer of the second conductivity type on said current blocking layer and on said third cladding layer where a portion of current blocking layer was removed; depositing first and second electrodes on said substrate and said contacting layer, respectively; and forming a pair of generally parallel opposed facets generally transverse to said first and second electrodes spaced from the portions of said second cladding layer into which the dopant was diffused.