Patent ID: 9287390
Filing Date: 2016-03-15
CPC Classification: H01L

Claim Text:
1. A method for manufacturing a semiconductor device comprising the steps of: forming an oxide insulating film over a substrate, wherein the oxide insulating film contains oxygen with a higher proportion than a proportion of oxygen in a stoichiometric composition; forming an oxide semiconductor film on and in contact with the oxide insulating film; reducing hydrogen concentration and oxygen vacancies in the oxide semiconductor film by performing a heat treatment; etching parts of the oxide semiconductor film to form an island-shaped oxide semiconductor film; forming a gate insulating film over the island-shaped oxide semiconductor film; and forming a gate electrode overlapping with the island-shaped oxide semiconductor film with the gate insulating film interposed therebetween, wherein an amount of oxygen desorbed from the oxide insulating film by the heat treatment is higher than or equal to 1.0×10