摘要 |
PROBLEM TO BE SOLVED: To provide a field-effect transistor that is small in a fluctuation amount of a threshold voltage to a BTS test, and that shows a high reliability.SOLUTION: A field-effect transistor comprises: a base material; a protection layer; a gate insulating layer formed between the base material and the protection layer; a source electrode and a drain electrode formed so as to be contacted with the gate insulating layer; a semiconductor layer formed at least between the source electrode and the drain electrode, and contacted with the gate insulating layer, the source electrode, and the drain electrode; and a gate electrode contacted with the gate insulating layer, and opposed to the semiconductor layer via the gate insulating layer. The protection layer has a first protection layer containing a first composite metal oxide containing Si and an alkali earth metal, and a second protection layer formed so as to be contacted with the first protection layer, and containing a second composite metal oxide containing an alkali earth metal and a rare earth element. |