Method of manufacturing a semiconductor device and liquid crystal display

摘要

A semiconductor device with a high reliability can be gained. The semiconductor device includes a substrate, a semiconductor layer, a gate insulating film and a gate electrode. The semiconductor layer is formed on the main surface of the substrate and includes source and drain regions adjoining each other via a channel region. The gate insulating film is formed on the channel region. The gate electrode is formed on the gate insulating film and has a sidewall. The gate insulating film includes an extended part which has sidewall positioned outside of the sidewall of the gate electrode. The source and the drain regions include high concentration impurity region which is formed in a region of the semiconductor layer apart from the sidewall of the extended part and low concentration impurity region, and which is formed in a region of the semiconductor layer positioned beneath the extended part.