Nitride based semiconductor device and process for preparing the same

Abstract

A process for preparing a nitride based semiconductor device in accordance with the present invention comprises growing a high temperature AlN single crystal layer on a substrate; growing a first GaN layer on the high temperature AlN single crystal layer in a first V/III ratio, under a first pressure of 300 Torr or more, such that the predominant direction of growth is the lateral direction; and growing a second GaN layer on the first GaN layer in a second V/III ratio lower than the first V/III ratio, under a second pressure lower than the first pressure such that the predominant direction of growth is the lateral direction.

1 - 12 . (canceled) 
   
   
       13 . A nitride semiconductor optical device prepared using the process according to claim  1 . 
   
   
       14 . A nitride based semiconductor device, comprising:
 a high temperature AlN single crystal layer formed on a substrate;   a GaN nucleation seed layer formed on the high temperature AlN single crystal layer;   a first GaN layer predominantly grown in the lateral direction on the GaN nucleation seed layer and having a crystal defect density of 10 9  cm −3  or less; and   a second GaN layer predominantly grown in the lateral direction on the first GaN layer and having a crystal defect density of 10 8  cm −3  or less.   
   
   
       15 . The nitride based semiconductor device as set forth in  claim 14 , wherein the high temperature AlN single crystal layer has a thickness of 200 to 1000 Å. 
   
   
       16 . The nitride based semiconductor device as set forth in  claim 14 , wherein the substrate is a silicone substrate.