Semiconductor light emitting device, method for manufacturing same, and method for forming underlying layer

Abstract

A method of making a semiconductor light emitting device including: (A) an underlying layer configured to be formed on a major surface of a substrate having a {100} plane as the major surface; (B) a light emitting part; and (C) a current block layer, wherein the underlying layer is composed of a III-V compound semiconductor and is formed on the major surface of the substrate by epitaxial growth, the underlying layer extends in parallel to a <110> direction of the substrate, a sectional shape of the underlying layer obtained when the underlying layer is cut along a virtual plane perpendicular to the <110> direction of the substrate is a trapezoid, and oblique surfaces of the underlying layer corresponding to two oblique sides of the trapezoid are {111}B planes, and the top surface of the underlying layer corresponding to an upper side of the trapezoid is a {100} plane.

1 . A method for manufacturing a semiconductor light emitting device, comprising the steps of:
 (a) forming a plurality of mask layers extending along a <110> direction on a major surface of a substrate having a {100} plane as the major surface, and exposing a part of the major surface of the substrate between the mask layers;   (b) epitaxially growing an underlying layer composed of a III-V compound semiconductor on the exposed part of the major surface of the substrate, and then removing the mask layers, a sectional shape of the underlying layer obtained when the underlying layer is cut along a virtual plane perpendicular to the <110> direction of the substrate being a trapezoid, oblique surfaces of the underlying layer corresponding to two oblique sides of the trapezoid being {111}B planes, and a top surface of the underlying layer corresponding to an upper side of the trapezoid being a {100} plane;   (c) forming, above the top surface of the underlying layer, a light emitting part arising from sequential stacking of a first compound semiconductor layer of a first conductivity type, an active layer, and a second compound semiconductor layer of a second conductivity type, and forming, on an exposed major surface of the substrate on which the underlying layer is not formed, a multilayer structure arising from sequential stacking of the first compound semiconductor layer of the first conductivity type, the active layer, and the second compound semiconductor layer of the second conductivity type; and   (d) forming, above the multilayer structure, a current block layer that covers at least an exposed side surface of the active layer of the light emitting part.   
     
     
         2 . The method for manufacturing a semiconductor light emitting device according to  claim 1 , wherein the underlying layer composed of a material having an energy band gap larger than an energy band gap of a material of the substrate is used. 
     
     
         3 . The method for manufacturing a semiconductor light emitting device according to  claim 1 , wherein the underlying layer composed of a material having an energy band gap larger than an energy band gap of a material of the first compound semiconductor layer is used. 
     
     
         4 . The method for manufacturing a semiconductor light emitting device according to  claim 1 , wherein the III-V compound semiconductor of the underlying layer contains, as an element, at least one of arsenic, antimony, and bismuth, and aluminum. 
     
     
         5 . The method for manufacturing a semiconductor light emitting device according to  claim 1 , wherein the III-V compound semiconductor of the underlying layer contains at least phosphorus as an element. 
     
     
         6 . A method for forming an underlying layer, comprising the steps of:
 (a) forming a plurality of mask layers on a major surface of a substrate, and exposing a part of the major surface of the substrate between the mask layers; and   (b) epitaxially growing an underlying layer composed of a III-V compound semiconductor on the exposed part of the major surface of the substrate, and then removing the mask layers, wherein   an impurity whose substitution site is a site occupied by a group III atom and an impurity whose substitution site is a site occupied by a group V atom are added to a material used for epitaxial growth of the underlying layer of an n conductivity type in order to cause the underlying layer to have the n conductivity type.   
     
     
         7 . The method for forming an underlying layer according to  claim 6 , wherein:
 the impurity whose substitution site is a site occupied by a group III atom is at least one kind of impurity selected from a group composed of silicon and tin; and   the impurity whose substitution site is a site occupied by a group V atom is at least one kind of impurity selected from a group composed of selenium, tellurium, and sulfur.   
     
     
         8 . The method for forming an underlying layer according to  claim 6 , wherein the substrate has the n conductivity type. 
     
     
         9 . The method for forming an underlying layer according to  claim 6 , wherein:
 the substrate has a p conductivity type;   subsequent to the step (a), a base layer of the p conductivity type is epitaxially grown on the exposed part of the major surface of the substrate, and then in the step (b), the underlying layer composed of the III-V compound semiconductor is epitaxially grown on the base layer instead of epitaxially growing the underlying layer composed of the III-V compound semiconductor on the exposed part of the major surface of the substrate;   a tunnel junction is formed by the base layer and the underlying layer; and   at least around an interface between the base layer and the underlying layer and vicinity of the interface, an impurity whose substitution site is a site occupied by a group III atom and an impurity whose substitution site is a site occupied by a group V atom are added to a material used for epitaxial growth of the base layer of the p conductivity type in order to cause the base layer to have the p conductivity type.   
     
     
         19 . The method for forming an underlying layer according to  claim 9 , wherein:
 the impurity whose substitution site is a site occupied by a group III atom in the base layer is at least one kind of impurity selected from a group composed of zinc, magnesium, beryllium, and manganese; and   the impurity whose substitution site is a site occupied by a group V atom in the base layer is carbon.   
     
     
         11 . A method for forming an underlying layer, comprising the steps of:
 (a) forming a plurality of mask layers on a major surface of a substrate, and exposing a part of the major surface of the substrate between the mask layers; and   (b) epitaxially growing an underlying layer composed of a III-V compound semiconductor on the exposed part of the major surface of the substrate, and then removing the mask layers, wherein   an impurity whose substitution site is a site occupied by a group III atom and an impurity whose substitution site is a site occupied by a group V atom are added to a material used for epitaxial growth of the underlying layer of a p conductivity type in order to cause the underlying layer to have the p conductivity type.   
     
     
         12 . The method for forming an underlying layer according to  claim 11 , wherein:
 the impurity whose substitution site is a site occupied by a group III atom is at least one kind of impurity selected from a group composed of zinc, magnesium, beryllium, and manganese; and   the impurity whose substitution site is a site occupied by a group V atom is carbon.   
     
     
         13 . The method for forming an underlying layer according to  claim 11 , wherein the substrate has the p conductivity type. 
     
     
         14 . The method for forming an underlying layer according to  claim 11 , wherein;
 the substrate has an n conductivity type;   subsequent to the step (a), a base layer of the n conductivity type is epitaxially grown on the exposed part of the major surface of the substrate, and then in the step (b), the underlying layer composed of the III-V compound semiconductor is epitaxially grown on the base layer instead of epitaxially growing the underlying layer composed of the III-V compound semiconductor on the exposed part of the major surface of the substrate,   a tunnel junction is formed by the base layer and the underlying layer; and   at least around an interface between the base layer and the underlying layer and vicinity of the interface, an impurity whose substitution site is a site occupied by a group III atom and an impurity whose substitution site is a site occupied by a group V atom are added to a material used for epitaxial growth of the base layer of the n conductivity type in order to cause the base layer to have the n conductivity type.   
     
     
         15 . The method for forming an underlying layer according to  claim 14 , wherein;
 the impurity whose substitution site is a site occupied by a group III atom in the base layer is at least one kind of impurity selected from a group composed of silicon and tin; and   the impurity whose substitution site is a site occupied by a group V atom in the base layer is at least one kind of impurity selected from a group composed of selenium, tellurium, and sulfur.