Patent ID: 6146945
Filing Date: 2000-11-14
Classification: H01L

Abstract:
A method for manufacturing a semiconductor device, comprising a step of forming a first diffusion layer of an opposite conductivity type in a semiconductor substrate, a step of forming a first insulation film on said semiconductor substrate, a step of removing part of said first insulation film on said first diffusion layer, a step of forming a second insulation film thinner than said first insulation film at a portion where said first insulation film is removed, a step of forming a first polysilicon film, a step of doping an impurity at a concentration of 1.times.10.sup.19 atoms/cm.sup.3 or higher to said first polysilicon film, a step of patterning said first polysilicon film, a step of forming a second diffusion layer of the opposite conductivity type in said semiconductor substrate, a step of forming a third insulation film in a surface of said semiconductor substrate including the upper surface of said first polysilicon film, a step of forming a second polysilicon film of 100 Angstroms to 1500 Angstroms on said third insulation film, a step of doping an impurity at 1.times.10.sup.15 -5.times.10.sup.19 atoms/cm.sup.3 to said second polysilicon film, a step of patterning said second polysilicon film, a step of doping an impurity at 1.times.10.sup.19 atoms/cm.sup.3 or higher to part or the entire said second polysilicon film, and a step of forming a third diffusion layer of the opposite conductivity type in said semiconductor substrate.