Method of manufacturing Schottky barrier gate FET

Claim 1

A method of manufacturing a Schottky barrier gate type FET comprising: a first step of forming a first film, made of a refractory metal or refractory metal compound, on a semiconductor substrate; a second step of forming a first ion-implanted region in said semiconductor substrate by an ion-implantation process during which impurity ions pass through said first film; a third step, independent of said second step, of forming second and third ion-implanted regions in said semiconductor substrate by an ion-implantation process during which impurity ions pass through said first film, said second and third ion-implanted regions being adjacent to said first ion-implanted region; a fourth step of forming a channel region, source region, and drain region, by annealing to activate said first, second, and third ion-implanted region using said first film as a protective film, and bringing said first film in Schottky contact with said channel region; and a fifth step of forming a Schottky gate electrode, in Schottky contact with said channel region, by patterning said first after said channel, source, and drain regions have been formed, with said first film being selectively maintained to prevent exposure of the channel region underlying the Schottky gate electrode.

Claim 2

A method of manufacturing a Schottky barrier gate type FET comprising: a first step of forming a first film, made of a refractory metal or refractory metal compound, on a semiconductor substrate; a second step of forming a first ion-implanted region in said semiconductor substrate by an ion-implantation process during which impurity ions pass through said first film; a third step, independent of said second step, of forming second and third ion-implanted regions in said semiconductor substrate by an ion-implantation process during which impurity ions pass through said first film, said second and third ion-implanted regions being adjacent to said first ion-implanted region; a fourth step of forming a channel region, source region, and drain region, by annealing to activate said first, second, and third ion-implanted region using said first film as a protective film, and bringing said first film in Schottky contact with said channel region; and a fifth step of forming a Schottky gate electrode, in Schottky contact with said channel region, by patterning said first after said channel, source, and drain regions have been formed, with said first film being selectively maintained to prevent exposure of the channel region underlying the Schottky gate electrode.