Method for manufacturing a semiconductor device
AssigneeSeiko Instruments Inc.
InventorJun Osanai
Life of this patent
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Abstract
The object is to provide a method for manufacturing a semiconductor device that is high in accuracy and function at low cost. In a semiconductor device having a resistance body and a non-volatile memory, by a manufacturing method to form a non-volatile memory select gate and floating gate with first polysilicon comparatively thick in film thickness and to form a non-volatile memory control gate and a resistance body with second polysilicon comparatively thin in film thickness, it is charactrized in that a non-volatile memory small in cell size and a highly accurate and stable resistance body can be simultaneously provided.
Claims4
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.
Dependencies are inferred from the claim text.