| abstract |
In a semiconductor device according to the present invention, an insulator layer on a substrate is provided with a trench. A gate electrode is formed in the trench so that an upper surface of the gate electrode is approximately flush with an upper surface of the insulator layer. On the gate electrode, a semiconductor layer is provided via a gate insulating film. At least one of a source electrode and a drain electrode is electrically connected to the semiconductor layer. Particularly, the gate insulating film includes an insulator coating film provided on the gate electrode, and an insulator CVD film formed on the insulator coating film. |