Patent ID: 7015083

Claim:
A method of manufacturing a semiconductor device comprising: a first step of forming a first semiconductor film comprising an amorphous structure on an insulating surface; a second step of adding a metallic element to the first semiconductor film; a third step of irradiating first laser light to the first semiconductor film after performing heat treatment to form a second semiconductor film comprising a crystalline structure and an oxide film on the second semiconductor film; a fourth step of performing oxidation of a surface of the second semiconductor film by using a solution comprising ozone; a fifth step of forming a third semiconductor film comprising an inert gas element over the oxide film; a sixth step of gettering the metallic element into the third semiconductor film to reduce the concentration of the metallic element in the second semiconductor film; a seventh step of removing the third semiconductor film; an eighth step of removing the oxide film; and a ninth step of irradiating second laser light in an inert gas atmosphere or in a vacuum to level a surface of the second semiconductor film.