Abstract: A method for forming a multilayer film by introducing a material gas into a reduced-pressure reaction chamber provided with a pair of parallel planer electrodes and supplying a high-frequency electric power to the electrodes thereby generating a plasma state therein and depositing a film on a substrate disposed on one of the electrodes, comprising the steps of (a) introducing a first material gas into the reaction chamber and supplying the high-frequency electric power to the electrodes thereby generating the plasma state and depositing a first film on the substrate, (b) introducing stepwise a preparatory gas and adjusting stepwise a distance between the electrodes, a pressure inside the chamber and a RF power supplied to the electrodes while continuously retaining the plasma state subsequently to step (a), and (c) introducing a second material gas into the reaction chamber while continuously retaining the plasma state thereby and depositing a second film on the first film.

Abstract: A thin film transistor includes an amorphous silicon layer formed on a substrate, a gate insulator formed on the amorphous silicon layer, a gate electrode formed on the gate insulator, source and drain contact regions of polycrystalline silicon formed in the amorphous silicon layer on both sides of the gate electrode, and source and drain electrodes formed respectively in contact with the source and drain contact regions. Particularly, the gate insulator includes a first insulating film which covers the amorphous silicon layer as a reflectivity reducing film for reducing the optical reflectivity of the amorphous silicon layer and the source and drain contact regions are formed by an annealing process for applying a laser beam to the amorphous silicon layer via the first insulating film.