SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To provide a semiconductor device including a gate insulation film wherein water absorbency is reduced and the film thickness equivalent to a silicon oxide film is 1.5 nm or below. SOLUTION: A silicon oxide film as a background film 2 is formed on a silicon substrate 1 and an La aluminate film 3 is formed on the silicon oxide film 2. A gate electrode 5 is formed on the La aluminate film 3. An extension region 6 is formed to an upper layer of the silicon substrate 1 with a channel region under the gate electrode 5 inbetween and a source / drain region 9 connected to the extension region 6 is formed. COPYRIGHT: (C)2005,JPO&NCIPI