InventorsUS Classes257/411, Composite or layered gate insulator (e.g., mixture such as silicon oxynitride)257/E29.255With field effect produced by insulated gate (EPO)Attorney, Agent or FirmForeign Documents- 2005-291625 JP 10/04/2005
International Class H01L 29/78 Issued Patent Number:7812412
Abstract textAccording to the present invention, a semiconductor device having a field effect transistor is provided. The field effect transistor comprises a gate insulating film 2 formed on a semiconductor layer 1 and a gate electrode 5 formed on the gate insulating film 2. The gate insulating film 2 has a silicon oxide film including a metal element 4 and nitrogen 3, and characteristics of the silicon oxide film are modified by adding the metal element 4 and nitrogen 3. Respective concentration distributions of the metal element 4 and nitrogen 3 in the gate insulating film 2 have maximum values on an interface side between the gate insulating film 2 and the gate electrode 5, and gradually decrease toward the semiconductor layer 1. | 
