Method of fabricating a Schottky field effect transistor

Claim 1

A method of fabricating a field effect transistor, comprising the steps of: forming a high density n-type region in a portion of a semiconductor substrate by ion implantation; forming an insulating layer on the surface of the semiconductor substrate; forming a window in a portion of said insulating layer; forming a) an n-type active region directly under the window formed in said portion of said insulating layer by ion implanting a p-type impurity on the surface of the semiconductor substrate with the insulating layer used as a mask, and b) a p-type region under said n-type active region in contact with said n-type active region by compensating the high density n-type region; forming a high melting point metal layer to make a Schottky gate electrode on the surface of the semiconductor substrate; annealing the semiconductor substrate with the insulating layer and the high melting point metal layer used as protection layers; forming at least one low specific resistance metal layer on the high melting point metal layer; removing a portion of said low specific resistance metal layer and the foregoing high melting point metal layer by means of a photolithographic technique and forming a Schottky gate electrode on the n-type active region exposed in the window; and forming a source electrode and a drain electrode on the high density n-type region in respective portions of the insulating layer.

Claim 2

A method of fabricating a field effect transistor, comprising the steps of: forming a high density n-type region in a portion of a semiconductor substrate by ion implantation; forming an insulating layer on the surface of the semiconductor substrate; forming a window in a portion of said insulating layer; forming a) an n-type active region directly under the window formed in said portion of said insulating layer by ion implanting a p-type impurity on the surface of the semiconductor substrate with the insulating layer used as a mask, and b) a p-type region under said n-type active region in contact with said n-type active region by compensating the high density n-type region; forming a high melting point metal layer to make a Schottky gate electrode on the surface of the semiconductor substrate; annealing the semiconductor substrate with the insulating layer and the high melting point metal layer used as protection layers; forming at least one low specific resistance metal layer on the high melting point metal layer; removing a portion of said low specific resistance metal layer and the foregoing high melting point metal layer by means of a photolithographic technique and forming a Schottky gate electrode on the n-type active region exposed in the window; and forming a source electrode and a drain electrode on the high density n-type region in respective portions of the insulating layer.

Claim 5

A method of fabricating a field effect transistor, comprising the steps of: forming a high density n-type region in a portion of a semiconductor substrate by ion implantation; forming an insulating layer on the surface of the semiconductor substrate; forming a window in a portion of said insulating layer; forming a) an n-type active region directly under the window formed in said portion of said insulating layer by ion implanting a p-type impurity on the surface of the semiconductor substrate with the insulating layer used as a mask, and b) a p-type region under said n-type active region and in contact with said n-type active region by compensating the high density n-type region; forming a high melting point metal layer to make a Schottky gate electrode on the surface of the semiconductor substrate; annealing the semiconductor substrate with the insulating layer and the high melting point metal layer used as an annealing cap; removing a portion of the high melting point metal layer by means of a photolithographic technique and forming a Schottky gate electrode on the n-type active region exposed in the window; forming at least one low specific resistance metal layer on said Schottky gate electrode; and forming a source electrode and a drain electrode on the high density n-type region and in respective portions of the insulating layer.

Claim 6

A method of fabricating a field effect transistor, comprising the steps of: forming a high density n-type region in a portion of a semiconductor substrate by ion implantation; forming an insulating layer on the surface of the semiconductor substrate; forming a window in a portion of said insulating layer; forming a) an n-type active region directly under the window formed in said portion of said insulating layer by ion implanting a p-type impurity on the surface of the semiconductor substrate with the insulating layer used as a mask, and b) a p-type region under said n-type active region and in contact with said n-type active region by compensating the high density n-type region; forming a high melting point metal layer to make a Schottky gate electrode on the surface of the semiconductor substrate; annealing the semiconductor substrate with the insulating layer and the high melting point metal layer used as an annealing cap; removing a portion of the high melting point metal layer by means of a photolithographic technique and forming a Schottky gate electrode on the n-type active region exposed in the window; forming at least one low specific resistance metal layer on said Schottky gate electrode; and forming a source electrode and a drain electrode on the high density n-type region and in respective portions of the insulating layer.