Method of fabricating semiconductor device

Abstract

A method of fabricating a semiconductor device includes the steps of: forming a well of first conductivity type and well of second conductivity type in a substrate; forming a field oxide layer and gate oxide layer on the substrate; forming first and second polysilicon layers on the field oxide layer and gate oxide layer, the first polysilicon layer being doped with impurities of second conductivity type, the second polysilicon layer being doped with impurities of first conductivity, the first and second polysilicon layers coming into contact with each other; patterning the first and second polysilicon layers to be isolated from each other, to thereby forming first and second gates; and forming a conductive layer between the first and second gates. Accordingly, isolation of N-type and P-type polysilicon layers from each other, and patterning of them for the purpose of forming a gate are carried out using one mask, effectively simplifying the etching process during a gate patterning process. Also, by providing a conductive layer between the first and second gates, which electrically connects those gates, mutual diffusion of the impurities doping the polysilicon layers is prevented.