Method of fabricating a double heterostructure injection laser utilizing a stripe-shaped region

Abstract

A semiconductor laser device includes a narrow elongated semiconductor region of the same conductivity type as another semiconductor region lying in the vicinity of the active region of the laser device. The elongated region extends in depth from the surface of the device to the vicinity of the active region. A surface semiconductor layer of an opposite conductivity type covers the entire surface of the device except for the elongated region.

I claim: 
     
       1. A method of producing a GaAs-Al x  Ga 1-x  As double hetero-structure injection laser comprising the steps of preparing an n-type GaAs substrate, epitaxially growing a first layer of n-type Al x  Ga 1-x  As on one major surface of said substrate, epitaxially growing a second layer of .[.P-type.]. GaAs on said first layer, epitaxially growing a third layer of p-type Al x  Ga 1-x  As on said second layer, epitaxially growing a fourth layer of n-type GaAs on said third layer, selectively diffusing p-type impurities into an elongated surface portion of said fourth layer to form a thin elongated p-type region on the surface of said fourth layer extending depthwise to a portion of said third layer, and forming first and second electrodes in ohmic contact with the whole surface of said fourth layer and with the other major surface of said substrate, respectively, wherein excitation current supplied through said first electrode is allowed to flow substantially only through the deepest portion of said thin elongated p-type region as the result of a reverse bias developed between said third and fourth layers. 
     
     
       2. The method of claim 1, further comprising the step of forming a pair of reflecting surfaces at the ends of said first through said fourth layers in the direction perpendicular to said thin elongated p-type region. 
     
     
       3. The method of claim 1, wherein said p-type impurities are of zinc.