Compound semiconductor device and its manufacture
AssigneeFujitsu Limited
InventorsTokuharu Kimura, Toshihide Kikkawa
Life of this patent
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Abstract
A compound semiconductor device has: a substrate; a GaN channel layer; an n-type AlqGa1-qN (0<q≦1) electron supply layer; an n-type GaN cap layer; a gate electrode disposed on the cap layer and forming a Schottky contact; recesses formed on both sides of the gate electrode on source and drain sides by at least partially removing the cap layer, the recesses having a bottom surface of a roughness larger than a roughness of a surface of the cap layer under the gate electrode; a source electrode disposed on the bottom surface of the recess on the source side; and a drain electrode disposed on the bottom surface of the recess on the drain side.
Claims15
A compound semiconductor device comprising:
- a substrate;
- a channel layer disposed above said substrate and consisting essentially of GaN;
- an electron supply layer disposed above said channel layer and consisting essentially of n-type AlqGa1-qN (0<q≦1);
- a cap layer disposed above said electron supply layer and consisting essentially of n-type GaN;
- a gate electrode disposed on said cap layer and forming a Schottky contact;
- recesses formed on both sides of said gate electrode on source and drain sides by removing at least part of said cap layer, said recess having a bottom surface of a roughness larger than a roughness of a surface of said cap layer under said gate electrode;
- a source electrode disposed on the bottom surface of said recess on the source side;
- and
- a drain electrode disposed on the bottom surface of said recess on the drain side.
A method of manufacturing a compound semiconductor device comprising the steps of:
- (a) epitaxially laminating above a substrate a channel layer consisting essentially of GaN, an electron supply layer consisting essentially of n-type AlqGa1-qN (0<q≦1) and a cap layer consisting essentially of n-type GaN, in this order recited;
- (b) forming a gate electrode on said cap layer, said gate electrode having a Schottky contact;
- (c) etching at least part of the cap layer to form recesses on both sides of said gate electrode on source and drain sides, in such a manner that a bottom surfaces of said recesses have a roughness larger than a roughness of a surface of said cap layer under said gate electrode;
- and
- (d) forming a source electrode and a drain electrode on the bottom surfaces of said recesses on the source and drain sides.
Dependencies are inferred from the claim text.