Method for manufacturing oxide semiconductor film and method for manufacturing semiconductor device

摘要

An object is to provide an oxide semiconductor having stable electric characteristics and a semiconductor device including the oxide semiconductor. A manufacturing method of a semiconductor film by a sputtering method includes the steps of holding a substrate in a treatment chamber which is kept in a reduced-pressure state; heating the substrate at lower than 400° C.; introducing a sputtering gas from which hydrogen and moisture are removed in the state where remaining moisture in the treatment chamber is removed; and forming an oxide semiconductor film over the substrate with use of a metal oxide which is provided in the treatment chamber as a target. When the oxide semiconductor film is formed, remaining moisture in a reaction atmosphere is removed; thus, the concentration of hydrogen and the concentration of hydride in the oxide semiconductor film can be reduced. Thus, the oxide semiconductor film can be stabilized.

主权项

1. A method for manufacturing a semiconductor device, comprising the steps of:
forming a gate electrode over a substrate; forming a gate insulating film over the gate electrode; forming an oxide semiconductor film over the gate insulating film by a sputtering method using an oxide semiconductor target in a chamber; forming a source electrode and a drain electrode over the oxide semiconductor film; forming a silicon oxide film over the source electrode and the drain electrode while the substrate is heated at 200° C. to 400° C.; and forming a silicon nitride film over the silicon oxide film while the substrate is heated at 200° C. to 400° C., wherein a filling rate of the oxide semiconductor target is greater than or equal to 90%, wherein the chamber is evacuated with use of a cryopump, and wherein, when the oxide semiconductor film is formed, a sputtering gas from which hydrogen and moisture are removed is introduced into the chamber.