Semiconductor device and method for manufacturing the same

Abstract

A semiconductor device includes: a semiconductor substrate; a buffer layer provided on the semiconductor substrate; a GaN channel layer provided on the buffer layer; an AlGaN electron travel layer provided on the GaN channel layer; a GaN cap layer provided on the AlGaN electron travel layer, having a nitrogen polarity, and on which a plurality of recesses are formed; and a gate electrode, a source electrode and a drain electrode provided in each of the plurality of recesses.

1 . A semiconductor device comprising:
 a semiconductor substrate;   a buffer layer provided on the semiconductor substrate;   a GaN channel layer provided on the buffer layer;   an AlGaN electron travel layer provided on the GaN channel layer;   a GaN cap layer provided on the AlGaN electron travel layer, having a nitrogen polarity, and on which a plurality of recesses are formed; and   a gate electrode, a source electrode and a drain electrode provided in each of the plurality of recesses.   
     
     
         2 . A method for manufacturing a semiconductor device comprising:
 forming a buffer layer, a GaN channel layer, an AlGaN electron travel layer and a GaN cap layer with a nitrogen polarity in order on a semiconductor substrate;   using the AlGaN electron travel layer as an etching stop layer and etching the GaN cap layer using KOH to form a plurality of recesses; and   forming a gate electrode, a source electrode and a drain electrode in each of the plurality of recesses.   
     
     
         3 . The method for manufacturing a semiconductor device according to  claim 2 , wherein SiN or SiO or TiW is used as a mask when etching the GaN cap layer using the KOH. 
     
     
         4 . The method for manufacturing a semiconductor device according to  claim 2 , wherein at least one of MBE, sputtering, plasma CVD and vapor deposition method is used as a film formation method for the buffer layer, the GaN channel layer, the AlGaN electron travel layer and the GaN cap layer. 
     
     
         5 . The method for manufacturing a semiconductor device according to  claim 3 , wherein at least one of MBE, sputtering, plasma CVD and vapor deposition method is used as a film formation method for the buffer layer, the GaN channel layer, the AlGaN electron travel layer and the GaN cap layer.