Strip buried heterostructure laser

Claim 1

A method of fabricating strip buried heterostructure junction lasers comprising the steps of: epitaxially growing an n-Al x Ga 1-x As first cladding layer on an n-GaAs wafer, 0<x<1, epitaxially growing an n-Al y Ga 1-y As waveguide layer on said first cladding layer, 0<y<1; y<x, epitaxially growing on said waveguide layer a GaAs layer from which the active layers of said lasers will be formed, epitaxially growing a thin p-Al q Ga 1-q As protective first layer, 0<q<1; q>y on said GaAs layer to protect the top surface of said active layers from the introduction of defects therein during subsequent processing steps, forming separated, parallel mask strips on said protective first layer, removing the entire protective first layer between said strips, thereby exposing the underlying GaAs layer, removing all but a few hundred Angstroms of said GaAs layer between said strips, thereby defining strip-like mesas of GaAs, the tops of said mesas being covered by said protective first layer, and the regions between said mesas having a thin protective second layer of GaAs on said Al y Ga 1-y As waveguide layer, thereby preventing oxidation of said waveguide layer in the atmosphere, and facilitating subsequent epitaxial growth thereon, removing said mask strips, epitaxially growing, from the liquid phase, an p-Al g Ga 1-g As, 0<g<1, g>yAs second cladding layer on said mesas and said thin protective second layer in such a manner that said thin protective second layer is dissolved in the solution used to grow said Al q Ga 1-q As second cladding layer which, therefore, between said mesas grows directly on said waveguide layer and on the top of said mesas incorporates said protective first layer therein, and forming individual lasers from said wafer.

Claim 2

A method of fabricating strip buried heterostructure junction lasers comprising the steps of: epitaxially growing an n-Al x Ga 1-x As first cladding layer on an n-GaAs wafer, 0<x<1, epitaxially growing an n-Al y Ga 1-y As waveguide layer on said first cladding layer, 0<y<1; y<x, epitaxially growing on said waveguide layer a GaAs layer from which the active layers of said lasers will be formed, epitaxially growing a thin p-Al q Ga 1-q As protective first layer, 0<q<1; q>y on said GaAs layer to protect the top surface of said active layers from the introduction of defects therein during subsequent processing steps, forming separated, parallel mask strips on said protective first layer, removing the entire protective first layer between said strips, thereby exposing the underlying GaAs layer, removing all but a few hundred Angstroms of said GaAs layer between said strips, thereby defining strip-like mesas of GaAs, the tops of said mesas being covered by said protective first layer, and the regions between said mesas having a thin protective second layer of GaAs on said Al y Ga 1-y As waveguide layer, thereby preventing oxidation of said waveguide layer in the atmosphere, and facilitating subsequent epitaxial growth thereon, removing said mask strips, epitaxially growing, from the liquid phase, an p-Al g Ga 1-g As, 0<g<1, g>yAs second cladding layer on said mesas and said thin protective second layer in such a manner that said thin protective second layer is dissolved in the solution used to grow said Al q Ga 1-q As second cladding layer which, therefore, between said mesas grows directly on said waveguide layer and on the top of said mesas incorporates said protective first layer therein, and forming individual lasers from said wafer.

Claim 3

A method of fabricating a semiconductor device having an active region therein comprising the steps of: epitaxially growing on a semiconductor body a first layer from which said active region of a predetermined geometry is to be formed, protecting the top surface of said first layer from the introduction of defects therein during subsequent processing by epitaxially growing a thin second layer thereon which can be selectively etched in the presence of said first layer, masking said second layer to define said geometry, selectively etching away said second layer in the mask openings to expose the underlying first layer, and removing at least a portion of said first layer to effect said geometry.

Claim 4

A method of fabricating a semiconductor device having an active region therein comprising the steps of: epitaxially growing on a semiconductor body a first layer from which said active region of a predetermined geometry is to be formed, protecting the top surface of said first layer from the introduction of defects therein during subsequent processing by epitaxially growing a thin second layer thereon which can be selectively etched in the presence of said first layer, masking said second layer to define said geometry, selectively etching away said second layer in the mask openings to expose the underlying first layer, and removing at least a portion of said first layer to effect said geometry.

Claim 6

A method of epitaxially growing a Group III-V compound second layer from the liquid phase on an Al-containing Group III-V compound first layer comprising the steps of: after growth of said Al-containing first layer, forming a non-Al-containing Group III-V compound epitaxial protective layer about several hundred Angstroms thick on a major surface thereof before exposing said first layer to an ambient which would otherwise oxidize said major surface, exposing said layers to said ambient, said protective layer preventing oxidation of said major surface, bringing a molten solution of said Group III-V compound of said second layer into contact with said protective layer so as to dissolve said protective layer into said solution and epitaxially grow said second layer directly on said major surface of said Al-containing first layer.

Claim 7

A method of epitaxially growing a Group III-V compound second layer from the liquid phase on an Al-containing Group III-V compound first layer comprising the steps of: after growth of said Al-containing first layer, forming a non-Al-containing Group III-V compound epitaxial protective layer about several hundred Angstroms thick on a major surface thereof before exposing said first layer to an ambient which would otherwise oxidize said major surface, exposing said layers to said ambient, said protective layer preventing oxidation of said major surface, bringing a molten solution of said Group III-V compound of said second layer into contact with said protective layer so as to dissolve said protective layer into said solution and epitaxially grow said second layer directly on said major surface of said Al-containing first layer.