Abstract A method of manufacturing an insulated-gate type field effect transistor includes the steps of forming an insulating film, on a semiconductor substrate, forming a first polycrystalline silicon layer on the insulating film, forming a second polycrystalline silicon layer on the frist polycrystalline silicon layer, patterning the first and second polycrystalline silicon layers to form a gate electrode and a masking layer, doping an impurity of a first conductivity type in the semiconductor substrate using the gate electrode and the masking layer as masks, thereby forming a source region and a drain region, starting etching the masking layer, detecting a natural oxide film on the gate electrode, stopping the etching, and ion-implanting an impurity of a second conductivity type in a region of the semiconductor substrate under the gate electrode through the gate electrode, thereby forming a channel-doped region. In this method, after the source and drain regions are formed, the impurity of the second conductivity type is ion-implanted in the substrate through the thin gate electrode to form the channel-doped region.
A method of manufacturing an insulated-gate type field effect transistor, comprising the steps of: forming an insulating film, on a semiconductor substrate; forming a first polycrystalline silicon layer on said insulating film; forming a natural oxide film on said first polycrystalline layer; forming a second polycrystalline silicon layer on said natural oxide film; patterning said first polycrystalline silicon layers, said natural oxide film, and said second polycrystalline silicon layers to form a gate electrode and a masking layer; doping an impurity of a first conductivity type in said semiconductor substrate using said gate electrode and said masking layer as masks, thereby forming a source region and a drain region; starting etching said masking layer; detecting said natural oxide film on said gate electrode; stopping the etching; and ion-implanting an impurity of a second conductivity type in a region of said semiconductor substrate under said gate electrode through said gate electrode, thereby forming a channel-doped region.
Claim 2
Independent Claim
155 words
A method of manufacturing an insulated-gate type field effect transistor, comprising the steps of: forming an insulating film, on a semiconductor substrate; forming a first polycrystalline silicon layer on said insulating film; forming a natural oxide film on said first polycrystalline layer; forming a second polycrystalline silicon layer on said natural oxide film; patterning said first polycrystalline silicon layers, said natural oxide film, and said second polycrystalline silicon layers to form a gate electrode and a masking layer; doping an impurity of a first conductivity type in said semiconductor substrate using said gate electrode and said masking layer as masks, thereby forming a source region and a drain region; starting etching said masking layer; detecting said natural oxide film on said gate electrode; stopping the etching; and ion-implanting an impurity of a second conductivity type in a region of said semiconductor substrate under said gate electrode through said gate electrode, thereby forming a channel-doped region.
Claim 3
Dependent Claim
40 words
A method according to claim 1, wherein said etching of said masking layer is performed in a plasma atmosphere, and said detecting of the natural oxide film on said gate electrode is performed by measuring a potential of the plasma.
Claim 4
Dependent Claim
18 words
A method according to claim 1, wherein a thickness of said gate electrode is 500 to 2500 Å.