Method of manufacturing semiconductor device
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorsShunpei Yamazaki, Yuhei Sato, Keiji Sato, Tetsunori Maruyama, Junichi Koezuka
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Abstract
In a manufacturing process of a transistor including an oxide semiconductor film, oxygen doping treatment is performed on the oxide semiconductor film, and then heat treatment is performed on the oxide semiconductor film and an aluminum oxide film provided over the oxide semiconductor film. Consequently, an oxide semiconductor film which includes a region containing more oxygen than a stoichiometric composition is formed. The transistor formed using the oxide semiconductor film can have high reliability because the amount of change in the threshold voltage of the transistor by a bias-temperature stress test (BT test) is reduced.
Claims15
A method for manufacturing a semiconductor device, the method comprising the steps of:
- forming a first insulating film;
- forming an oxide semiconductor film on and in contact with the first insulating film;
- performing a first heat treatment after forming the oxide semiconductor film;
- forming a second insulating film over the oxide semiconductor film after performing the first heat treatment;
- performing an oxygen ion implantation treatment after forming the second insulating film so that a region where amount of oxygen exceeds that in a stoichiometric composition is formed in a stack comprising the first insulating film, the oxide semiconductor film and the second insulating film;
- and
- performing a second heat treatment after performing oxygen ion implantation treatment so that oxygen is supplied to the oxide semiconductor film,
- wherein the region comprises at least an interface between the first insulating film and the oxide semiconductor film or an interface between the second insulating film and the oxide semiconductor film, and
- wherein the second insulating film has a barrier property with respect to each of hydrogen, moisture and oxygen.
Dependencies are inferred from the claim text.