Nitride-based semiconductor device and method of fabricating the same

Abstract

A method of fabricating a nitride-based semiconductor device capable of reducing contact resistance between a nitrogen face of a nitride-based semiconductor substrate or the like and an electrode is provided. This method of fabricating a nitride-based semiconductor device comprises steps of etching the back surface of a first semiconductor layer consisting of either an n-type nitride-based semiconductor layer or a nitride-based semiconductor substrate having a wurtzite structure and thereafter forming an n-side electrode on the etched back surface of the first semiconductor layer.

1 - 27 . (canceled)  
     
     
         28 . A nitride-based semiconductor device comprising: 
 a first semiconductor layer, consisting of either an n-type nitride-based semiconductor layer having a wurtzite structure or an n-type nitride-based semiconductor substrate having a wurtzite structure; and    an n-side electrode formed on a back surface of said first semiconductor layer,    wherein a dislocation density is not more than 1×10 9  cm −2  in the vicinity of the interface between said first semiconductor layer and said n-side electrode, and    contact resistance between said n-side electrode and said first semiconductor layer is not more than 0.05 Ωcm 2 .    
     
     
         29 . The nitride-based semiconductor device according to  claim 28 , wherein said dislocation density is not more than 1×10 6  cm −2  in the vicinity of the interface between said first semiconductor layer and said n-side electrode.  
     
     
         30 . The nitride-based semiconductor device according to  claim 28 , wherein an electron carrier concentration is at least 1×10 17  cm −3  in the vicinity of the interface between said first semiconductor layer and said n-side electrode.  
     
     
         31 . The nitride-based semiconductor device according to  claim 28 , wherein the back surface of said first semiconductor layer includes a nitrogen face of said first semiconductor layer.  
     
     
         32 . The nitride-based semiconductor device according to  claim 28 , wherein the back surface of said first semiconductor layer has predetermined thickness processed.  
     
     
         33 . The nitride-based semiconductor device according to  claim 28 , wherein said first semiconductor layer includes an n-type dopant.  
     
     
         34 . The nitride-based semiconductor device according to  claim 33 , wherein said n-type dopant is oxygen.  
     
     
         35 . The nitride-based semiconductor device according to  claim 34 , further comprising an n-type nitride semiconductor layer on said first semiconductor layer, said n-type nitride semiconductor layer doped either Si, Se, or Ge.  
     
     
         36 . The nitride-based semiconductor device according to  claim 28 , wherein said first semiconductor layer is formed by HVPE.