SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME

摘要

A larger substrate can be used, and a transistor having a desirably high field-effect mobility can be manufactured through formation of an oxide semiconductor layer having a high degree of crystallinity, whereby a large-sized display device, a high-performance semiconductor device, or the like can be put into practical use. A single-component oxide semiconductor layer is formed over a substrate; then, crystal growth is carried out from a surface to an inside by performing heat treatment at 500 °C to 1000 °C inclusive, preferably 550 °C to 750 °C inclusive so that a single-component oxide semiconductor layer including single crystal regions is formed; and a multi-component oxide semiconductor layer including single crystal regions is stacked over the single-component oxide semiconductor layer including single crystal regions.