Optical semiconductor device having an active layer containing N

Abstract

A laser diode includes a substrate, a lower cladding layer or a lower optical waveguide layer substantially free from Al and provided on the substrate, an active layer of a mixed crystal containing Ga and In as a group III element and N, As and/or P as a group V element, provided on the lower cladding layer; and an upper cladding layer or an upper optical waveguide layer substantially free from Al and provided on the active layer.

1 - 13 . (canceled)  
     
     
         14 . A semiconductor device, comprising: 
 an InP substrate;    an active layer provided over said substrate, said active layer containing Ga, In, N, As and P; and    another layer free from Al formed adjacent to said active layer at either one side or both sides thereof, said another layer having a composition represented as Ga d In 1-d N c As f P 1-c-f  (0≦d≦1, 0≦e<1, 0≦f≦1).    
     
     
         15 . A semiconductor device as claimed in  claim 14 , said active layer and said another layer accumulating therein a strain of respective different types.  
     
     
         16 . A semiconductor device as claimed in  claim 15 , wherein said active layer accumulates therein a compressive strain, and said another layer accumulates therein a tensile strain.  
     
     
         17 . A semiconductor device, comprising: 
 an InP substrate;    an active layer provided over said substrate; and    another layer free from Al formed adjacent to said active layer at either one side or both sides thereof, said another layer containing N and a group V element other than N.    
     
     
         18 . A semiconductor device as claimed in  claim 17 , wherein said semiconductor device comprises a further layer free from Al provided at a side of said another layer away from said active layer.  
     
     
         19 . A semiconductor device as claimed in  claim 18 , wherein said further layer has a composition represented as Ga d In 1-d N c As f P 1-e-f  (0≦d≦1, 0≦e<1, 0≦f≦1).  
     
     
         20 . A semiconductor device, comprising: 
 an InP substrate formed of GaAs;    an active layer provided over said substrate, said active layer containing N and a group V element other than N; and    another layer free from Al provided adjacent to said active layer at one side or both sides thereof, said another layer containing N and a group V element other than N, said active layer and said another layer accumulating therein a strain of respective, different types.    
     
     
         21 . A semiconductor device as claimed in  claim 20 , wherein said active layer accumulates therein a compressive strain and said another layer accumulates therein a tensile strain.  
     
     
         22 . A semiconductor device as claimed in  claim 20 , wherein said semiconductor device comprises a further layer free from Al provided at a side of said another layer away from said active layer.  
     
     
         23 . An optical semiconductor device, comprising: 
 an InP substrate; and    an active region provided over said InP substrate, said active region at least comprising:    a quantum well layer containing N and a group V element other than N, said quantum well layer acting as a light-emitting layer; and    another layer free from Al contacting said quantum well layer at one side or both sides of said quantum well layer, said another layer containing N and a group V element other than N.    
     
     
         24 . An optical semiconductor device as claimed in  claim 23 , wherein said quantum well layer and said another layer accumulate therein a strain of respective, different types.