Process for fabricating a semiconductor integrated circuit device

Abstract

Herein disclosed is a semiconductor integrated circuit device comprising an SRAM having its memory cell composed of transfer MISFETs to be controlled through word lines and drive MISFETs, and a method of forming this device. The gate electrodes of the drive MISFETs and of the transfer MISFETs of the memory cell, and the word lines, are individually formed of different conductive layers. The two transfer MISFETs of the memory cell have their individual gate electrodes connected with two respective word lines spaced from each other and extended in an identical direction. The source line is formed of a conductive layer identical to that of the word line. An oxidation resisting film is formed on the gate electrodes of the drive MISFETs so as to reduce stress caused by oxidization of edge portions of these gate electrodes, and to reduce a resulting leakage current. A thickness of an oxide film formed on gate electrodes of the transfer MISFETs and word lines is thicker than an oxide film formed on gate electrodes of the drive MISFETs, so that data line pads can be formed in self-alignment with the oxide film and side wall spacers on the gate electrodes of the transfer MISFETs.