Light-emitting semiconductor device using group III nitrogen compound

Abstract

A method of producing a light-emitting semiconductor device of a group III nitride compound includes forming an N-layer of an N-type conduction, the N-layer comprising gallium nitride, forming a high carrier concentration N + -layer satisfying the formula (Al x3 Ga 1-x3 ) y3 In 1-y3 N, wherein 0≦x3≦1, 0≦y3≦1 and 0≦x3+y3≦1, on the N-layer, forming an emission layer of a group III nitride compound semiconductor satisfying the formula, Al x1 Ga y1 In 1-x1-y1 N, where 0≦x1≦1, 0≦y1≦1 and 0≦x1+y1≦1 on the high carrier concentration layer N + layer, doping Si and Zn into the emission layer, forming a P-layer of a P-type conduction, on the emission layer, the P-layer including aluminum gallium nitride satisfying the formula Al x2 Ga 1-x2 N, wherein 0≦x2≦1, and forming a contact layer of a P-type conduction, on the P-type layer, the contact layer including gallium nitride.

1 . A method of producing a light-emitting semiconductor device of a group III nitride compound, comprising:
 forming an N-layer of an N-type conduction, said N-layer comprising gallium nitride;   forming a high carrier concentration N + -layer satisfying the formula (Al x3 Ga 1-x3 ) y3 In 1-y3 N, wherein 0≦x3≦1 and 0≦y3≦1 and 0≦x3+y3≦1, on said N-layer;   forming an emission layer of a group III nitride compound semiconductor satisfying the formula, Al x1 Ga y1 In 1-x1-y1 N, where 0≦x1≦1, 0≦y1≦1 and 0≦x1+y1≦1 on said high carrier concentration layer N + -layer;   doping Si and Zn into said emission layer;   forming a P-layer of a P-type conduction, on said emission layer, said P-layer comprising aluminum gallium nitride satisfying the formula Al x2 Ga 1-x2 N, wherein 0≦x2≦1; and   forming a contact layer of a P-type conduction, on said P-type layer, said contact layer comprising gallium nitride.   
     
     
         2 . The method according to  claim 1 , wherein said high carrier concentration N + -layer has an electron concentration of 10 8 /cm 3  order. 
     
     
         3 . The method according to  claim 1 , wherein the contact layer of P-type conduction has a Mg concentration of 10 20 /cm 3  order. 
     
     
         4 . The method according to  claim 1 , wherein an electron concentration of said N + -layer is larger than an electron concentration of said N-layer. 
     
     
         5 . The method according to  claim 1 , wherein said high carrier concentration N + -layer comprises a quaternary compound. 
     
     
         6 . The method according to  claim 1 , wherein the high carrier concentration N + -layer has a thickness of 2 μm-4 μm. 
     
     
         7 . A semiconductor light emitting device comprising:
 an n-type clad layer consisting of a gallium nitride base compound semiconductor;   an active layer consisting of a gallium nitride based compound semiconductor, said active layer being made from a material having a band gap energy smaller than that of said n-type clad layer; and   a p-type clad layer consisting of a gallium nitride based compound semiconductor, said p-type clad layer being made from a material having a band gap energy greater than that of said active layer, and sandwiching said active layer accompanying with said n-type clad layer,   wherein said materials of said n-type clad layer and said p-type clad layer are selected as to make a band gap energy of said n-type clad layer smaller than the band gap energy of said p-type clad layer.   
     
     
         8 . A semiconductor light emitting device comprising:
 a substrate; and   GaN-type compound semiconductor layers stacked on the substrate, the GaN-type layers including:   at least one active layer;   at least one n-type layer; and   at least one p-type layer,   wherein a band gap energy of the one n-type layer is smaller than a band gap energy of the one p-type layer.