Method for manufacturing semiconductor device

摘要

An object is to provide a semiconductor device having stable electric characteristics in which an oxide semiconductor is used. An oxide semiconductor layer is subjected to heat treatment for dehydration or dehydrogenation treatment in a nitrogen gas or an inert gas atmosphere such as a rare gas (e.g., argon or helium) or under reduced pressure and to a cooling step for treatment for supplying oxygen in an atmosphere of oxygen, an atmosphere of oxygen and nitrogen, or the air (having a dew point of preferably lower than or equal to −40° C., still preferably lower than or equal to −50° C.) atmosphere. The oxide semiconductor layer is thus highly purified, whereby an i-type oxide semiconductor layer is formed. A semiconductor device including a thin film transistor having the oxide semiconductor layer is manufactured.

主权项

1. A method for manufacturing a semiconductor device, comprising the steps of:
forming an oxide semiconductor layer over a substrate in a chamber; reducing hydrogen concentration in the oxide semiconductor layer by performing a heat treatment on the oxide semiconductor layer; and performing a treatment for supplying oxygen on the oxide semiconductor layer after the heat treatment, wherein moisture in the chamber is removed by a vacuum pump, and wherein an oxygen deficiency in the oxide semiconductor layer is generated by the heat treatment and then filled by the treatment for supplying oxygen.