| 摘要 |
PROBLEM TO BE SOLVED: To provide a thin film transistor having favorable electrical characteristics and high reliability, and provide a display device using the thin film transistor as a switching element.SOLUTION: In a channel protected thin film transistor in which an oxide semiconductor is used for a channel formation region, an oxide semiconductor layer which is dehydrated or dehydrogenated by heat treatment is used as an active layer, a crystal region formed of nanocrystals is included in a surface part of the channel formation region, and the other part is formed of an amorphous material or a mixture of an amorphous material and microcrystals, where an amorphous region is dotted with the microcrystals. By using an oxide semiconductor layer having such a configuration, a change to an N-type caused by re-entry of moisture or elimination of oxygen to or from the surface part and generation of a parasitic channel can be prevented and contact resistance with a source electrode and a drain electrode can be reduced. |
