Method of forming polycrystalline silicon layer and surface treatment apparatus therefor.

摘要

A method of forming a polycrystalline silicon thin film improved in crystallinity and a channel of a transistor superior in electrical characteristics by the use of such a polycrystalline silicon thin film. An amorphous silicon layer of a thickness preferably of 30 nm to 50 nm is formed on a substrate. Next, substrate heating is performed to set the amorphous silicon layer to preferably 350 DEG C to 500 DEG C, more preferably 350 DEG C to 450 DEG C. Then, at least the amorphous silicon layer is exposed to laser light of an excimer laser in an extent greater than approximiately 10 cm<2> by single shot exposure. The energy density is 100 mJ/cm<2> to 500 mJ/cm<2>, preferably 280 mJ/cm<2> to 330 mJ/cm<2>. The pulse width is 80 ns to 200 ns, preferably 140 ns to 200 ns, so as to directly anneal the amorphous silicon layer and form a polycrystalline silicon thin film. The total energy of the laser used for the irradiation of excimer laser light is at least 5J, preferably at least 10J. A surface treatment laser appraratus and different surface treatments e.g. oxidation or nitridation are also described.