Hitachi, Ltd.

Kikuo Watanabe

Hiroshi Miki

Tomoko Sekiguchi

Kenichi Takeda

Shinichiro Kimura

Yuichi Matsui

Renichi Yamada

Osamu Tonomura

A semiconductor device having a DRAM has a capacitor in which a dielectric film and an upper electrode are laminated on a lower electrode comprising a polysilicone, in which a natural oxide film oxidized by oxygen in the atmosphere grows to at least 1.5 nm on the surface of a lower electrode of the capacitor. Further, in forming the dielectric film, the dioxide film further grows in the case of using an oxidative raw material. This brings forth a reduction in capacitance, and an increase of a leakage current is caused. Therefore, after a dielectric film having a reduction property has been formed, the reduction property is promoted by a heat treatment to thereby reduce a dioxide film and realize making the dioxide film on the lower electrode surface thinner.

Semiconductor device and method of fabrication

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.

Semiconductor device and manufacturing method thereof

Growing community of inventors

Sayama, Japan

Kikuo Watanabe