US Patent 7192821 Manufacturing process of semi-conductor device

Exemplary embodiments discourage or prevent impurities from mixing in a film of a semiconductor layer in a manufacturing process of a semiconductor device. A manufacturing process of a semiconductor device includes first forming a semiconductor layer, second removing hydrogen from inside the semiconductor layer, and third terminating by combining elements such as hydrogen with a surface of the semiconductor layer through exposure to hydrogen plasma and the like. At least the second removing and the third terminating are consecutively performed under an environment isolated from air. According to this process, it is possible to prevent or discourage impurities contained in air and the like from combining on the surface of the semiconductor film. It is possible to discourage or prevent impurities from mixing (diffusing) in the semiconductor layer in crystallization through irradiation by light following the third terminating.