Method for manufacturing thin film semiconductor device

摘要

An object is to provide a semiconductor device with stable electric characteristics in which an oxide semiconductor is used. The impurity concentration in the oxide semiconductor layer is reduced in the following manner: a silicon oxide layer including many defects typified by dangling bonds is formed in contact with the oxide semiconductor layer, and an impurity such as hydrogen or moisture (a hydrogen atom or a compound including a hydrogen atom such as H2O) included in the oxide semiconductor layer is diffused into the silicon oxide layer. Further, a mixed region is provided between the oxide semiconductor layer and the silicon oxide layer. The mixed region includes oxygen, silicon, and at least one kind of metal element that is included in the oxide semiconductor.

主权项

1. A manufacturing method of a semiconductor device comprising steps of:
forming a gate electrode layer over a substrate, forming a gate insulating layer over the gate electrode layer; introducing the substrate into a first treatment chamber; performing a first sputtering operation using an oxide semiconductor target to form an oxide semiconductor layer over the gate insulating layer; heating the substrate, the gate insulating layer, and the oxide semiconductor layer at a temperature higher than or equal to 100° C. and lower than or equal to 400° C. after performing the first sputtering operation; and forming, over and in contact with the oxide semiconductor layer, a silicon oxide layer including defects at a temperature higher than or equal to 0° C. and lower than or equal to 50° C. after the step of heating the substrate the gate insulating layer, and the oxide semiconductor layer, wherein the substrate is heated during the step of forming of the oxide semiconductor layer at a first temperature.