Manufacturing method for semiconductor laser with mesa stripe

Claim 1

A method of manufacturing a semiconductor laser for emitting a continuous laser beam of visible wavelength range, said method comprising the steps of: (a) forming a double hetero-structure on a semiconductor substrate of a first conductivity type made of a III-V compound semiconductor material by means of metal organic chemical vapor deposition, said double hetero-structure comprising: a first semiconductive cladding layer of the first conductivity type, an active layer of semiconductor material formed on said first cladding layer, a second semiconductive cladding layer of a second conductivity type formed on said active layer, and a third semiconductive cladding layer of the second conductivity type formed on said second cladding layer and made of compound semiconductor material comprising a plurality of III-elements and one V-element; (b) forming a first semiconductive contact layer of the second conductivity type on said double hetero-structure; (c) forming an insulative layer on said first contact layer; (d) applying selective etching to said first contact layer by using said insulative layer as a mask, thereby forming a mesa-shaped layer having a flat top surface and slanted sides; (e) applying selective etching to said third cladding layer by using said mesa-shaped layer as a mask, thereby forming a waveguide channel and also a mesa-shaped layer having a flat top surface and slanted sides; and (f) forming a semiconductive, current-blocking layer of the first conductivity type on the resultant structure, said current-blocking layer covering the slanted sides of said third cladding layer and also the slanted sides of said first contact layer and being made of substantially the same III-V compound semiconductor as said substrate.

Claim 2

A method of manufacturing a semiconductor laser for emitting a continuous laser beam of visible wavelength range, said method comprising the steps of: (a) forming a double hetero-structure on a semiconductor substrate of a first conductivity type made of a III-V compound semiconductor material by means of metal organic chemical vapor deposition, said double hetero-structure comprising: a first semiconductive cladding layer of the first conductivity type, an active layer of semiconductor material formed on said first cladding layer, a second semiconductive cladding layer of a second conductivity type formed on said active layer, and a third semiconductive cladding layer of the second conductivity type formed on said second cladding layer and made of compound semiconductor material comprising a plurality of III-elements and one V-element; (b) forming a first semiconductive contact layer of the second conductivity type on said double hetero-structure; (c) forming an insulative layer on said first contact layer; (d) applying selective etching to said first contact layer by using said insulative layer as a mask, thereby forming a mesa-shaped layer having a flat top surface and slanted sides; (e) applying selective etching to said third cladding layer by using said mesa-shaped layer as a mask, thereby forming a waveguide channel and also a mesa-shaped layer having a flat top surface and slanted sides; and (f) forming a semiconductive, current-blocking layer of the first conductivity type on the resultant structure, said current-blocking layer covering the slanted sides of said third cladding layer and also the slanted sides of said first contact layer and being made of substantially the same III-V compound semiconductor as said substrate.