Patent ID: 8062913

Claim:
A method of manufacturing a semiconductor structure ( 1 ) formed of nitrides of group III metals having wurtzite crystal structure and grown in vapor phase on a (0001) oriented semiconductor substrate ( 2 , 3 ), the method comprising steps of growing in vapor phase a bottom cladding layer ( 4 ); growing in vapor phase a diffusion region ( 6 , 7 ) above the bottom cladding layer for diffusing light propagating within the semiconductor structure ( 1 ), the diffusion region having a refractive index different from that of the bottom cladding layer and non-flat surfaces; and growing in vapor phase a top cladding layer ( 5 ) above the diffusion region, the top cladding layer having a flat upper surface ( 9 ), a refractive index different from that of the diffusion region, and a lattice constant the same as that of the bottom cladding layer, characterized in that the growing of the diffusion region comprises steps of growing a plurality of diffusion layers ( 6 , 7 ), compositions and thicknesses of the diffusion layers having been chosen to avoid formation of strain-induced dislocations in the layer interfaces, and adjacent diffusion layers ( 6 , 7 ) having different refractive indices in order to further enhance the diffusion efficiency.