Method of making a thin film transistor

Abstract

A structure and fabricating method of a thin film transistor which is suitable for an SRAM memory cell. The thin film transistor structure includes: an insulation substrate; a gate electrode formed on the insulation substrate; a gate insulation film formed on the gate electrode and on the insulation substrate; a semiconductor layer formed on the gate insulation film; channel regions formed in parts of the semiconductor layer at both sides of the gate electrode; a high density first conductive type first impurity region formed in the semiconductor layer over the gate electrode; and first conductive type second impurity regions of having an LDD structure formed in parts of the semiconductor layer over the insulation substrate except under the gate electrode. The method for fabricating a thin film transistor includes processes for: forming a gate electrode on an insulation substrate and forming a gate insulation film on the overall surface thereof; forming a semiconductor layer on the gate insulation film; forming diffusion preventing spacers on the semiconductor layer; forming impurity-containing spacers on the diffusion preventing spacers; diffusing impurities from the impurity-containing spacers into the semiconductor layer; and injecting high density source/drain ions into the semiconductor layer with the insulation film side walls used as masks.