Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
191 words
A method of fabricating a semiconductor device, comprising the steps of: preparing a semiconductor substrate having a first conductivity type; introducing impurities corresponding to the first conductivity type into the substrate to form a first region; introducing impurities corresponding to a second conductivity type into the substrate to form a second region, the second conductivity type differing from the first conductivity type, the second region being more distant from a surface of the substrate than the first region is; forming a gate insulating film on the surface of the substrate; forming a gate electrode on the gate insulating film: introducing impurities corresponding to the first conductivity type into a portion of the substrate to form a third region while using the gate electrode as a mask, wherein at least a part of the portion of the substrate overlaps a portion of the second region, and an impurity concentration in the third region is higher than an impurity concentration in the second region; and introducing impurities corresponding to the second conductivity type into the substrate to form a source region and a drain region while using the gate electrode as a mask.
Claim 2
Independent Claim
191 words
A method of fabricating a semiconductor device, comprising the steps of: preparing a semiconductor substrate having a first conductivity type; introducing impurities corresponding to the first conductivity type into the substrate to form a first region; introducing impurities corresponding to a second conductivity type into the substrate to form a second region, the second conductivity type differing from the first conductivity type, the second region being more distant from a surface of the substrate than the first region is; forming a gate insulating film on the surface of the substrate; forming a gate electrode on the gate insulating film: introducing impurities corresponding to the first conductivity type into a portion of the substrate to form a third region while using the gate electrode as a mask, wherein at least a part of the portion of the substrate overlaps a portion of the second region, and an impurity concentration in the third region is higher than an impurity concentration in the second region; and introducing impurities corresponding to the second conductivity type into the substrate to form a source region and a drain region while using the gate electrode as a mask.
Claim 3
Dependent Claim
58 words
The method according to claim 1, further comprising the step of forming a second insulating film on the substrate and the gate electrode, wherein the source region and the drain region are formed after the second insulating film is formed, and a width of the third region is adjusted according to a thickness of the second insulating film.
Claim 4
Dependent Claim
22 words
The method according to claim 1, wherein the step of introducing impurities to form the third region uses tilt angle ion implantation.
Claim 5
Independent Claim
206 words
A method of fabricating a semiconductor device, comprising the steps of: preparing a semiconductor substrate having a first conductivity type; introducing impurities corresponding to the first conductivity type into the substrate to form a first region; introducing impurities corresponding to a second conduction type into the substrate to form a second region, the second conductivity type differing from the first conductivity type, the second region being more distant from a surface of the substrate than the first region is; forming a gate insulating firm on the surface of the substrate; forming a gate electrode on the gate insulating film; forming a resist which covers areas on the substrate; introducing impurities corresponding to the first conductivity type into a portion of the substrate to form a third region while using the gate electrode and the resist as a mask, wherein at least a part of the portion of the substrate overlaps a portion of the second region, and an impurity concentration in the third region is higher than an impurity concentration in the second region; removing the resist; and introducing impurities corresponding to the second conductivity type into the substrate to form a source region and a drain region while using the gate electrode as a mask.
Claim 6
Independent Claim
206 words
A method of fabricating a semiconductor device, comprising the steps of: preparing a semiconductor substrate having a first conductivity type; introducing impurities corresponding to the first conductivity type into the substrate to form a first region; introducing impurities corresponding to a second conduction type into the substrate to form a second region, the second conductivity type differing from the first conductivity type, the second region being more distant from a surface of the substrate than the first region is; forming a gate insulating firm on the surface of the substrate; forming a gate electrode on the gate insulating film; forming a resist which covers areas on the substrate; introducing impurities corresponding to the first conductivity type into a portion of the substrate to form a third region while using the gate electrode and the resist as a mask, wherein at least a part of the portion of the substrate overlaps a portion of the second region, and an impurity concentration in the third region is higher than an impurity concentration in the second region; removing the resist; and introducing impurities corresponding to the second conductivity type into the substrate to form a source region and a drain region while using the gate electrode as a mask.