Patent ID: 6147364
Filing Date: 2000-11-14
Classification: B82Y,H01L,H01S

Abstract:
A gallium nitride (GaN)-based semiconductor device comprising:a substrate;a first buffer layer formed on said substrate and not being made from a single-crystal;a second buffer layer formed on said first buffer layer which is a single-crystal layer consisting mainly of GaN with a magnesium (Mg) concentration of N.sub.bg1 cm.sup.-3, the single-crystal layer having a thickness of d.sub.1 .mu.m;a semiconductor layer consisting mainly of Ga.sub.1-x Al.sub.x N having an Al composition x of at least 0.02 and not higher than 1 and having a thickness of d.sub.2 .mu.m, said single-crystal layer being situated between said substrate and said semiconductor layer, and Mg being added to said semiconductor layer at a concentration of N.sub.Mg cm.sup.-3, andan active layer situated between said single-crystal layer and said semiconductor layer and formed to effect laser oscillation;wherein said Al composition x, said concentration N.sub.Mg, said concentration N.sub.bg1, said thickness d.sub.1 and said thickness d.sub.2 have the following relationship:d.sub.1 /(1600.times.x)<d.sub.2 <3.6.times.10.sup.-3 .times.logN/(x+0.02)+0.02wherein when N.sub.Mg >N.sub.bg1, N cm.sup.-3 =N.sub.Mg -N.sub.bg1, and when N.sub.Mg .ltoreq.N.sub.bg1, N is equal to an Mg background level in additive-free Ga.sub.1-x Al.sub.x N.