Semiconductor device and manufacturing method thereof

摘要

Disclosed is herein a semiconductor device having a DRAM with less scattering of threshold voltage of MISFET in a memory cell and having good charge retainability of a capacitor, and a manufacturing method of the semiconductor device. An anti-oxidation film is formed to the side wall of a gate electrode before light oxidation thereby suppressing the oxidation of the side wall for the gate electrode and decreasing scattering of the thickness of the film formed to the sidewall in an asymmetric diffusion region structure in which the impurity concentration of an n-type semiconductor region and a p-type semiconductor region on the side of the data line is made relatively higher than the impurity concentration in the n-type semiconductor region and p-type semiconductor region on the side of the capacitor, respectively.