Method for forming ZnO film, method for forming ZnO semiconductor layer, method for fabricating semiconductor device, and semiconductor device

摘要

A ZnO buffer layer having an electric conductivity of 1x10^-9 S/cm or lower or alternatively a ZnO buffer layer having a diffraction peak of a crystal face other than (002) and (004) in X-ray diffraction is formed on a substrate by sputtering. A ZnO semiconductor layer is formed on the ZnO buffer layer. The ZnO semiconductor layer is formed under the condition that the flow rate ratio of an oxygen gas in a sputtering gas is lower than that in the formation of the ZnO buffer layer.