SEMICONDUCTOR DEVICE AND ITS MANUFACTURING METHOD

PROBLEM TO BE SOLVED: To provide a semiconductor device wherein nitrogen is selectively introduced in a depthwise direction of an insulation film having a high dielectric constant. SOLUTION: Using a fact that nitriding reaction in an ammonia (NH3) atmosphere is different depending on a silicon composition of a metal silicate, selective nitriding of the insulation film is conducted. Consequently, a high dielectric constant gate insulation film having a multilayer structure including a nitrogen introduction layer having an effect of suppressing the penetration of a dopant such as B and a nitriding prevention layer which essentially has no requirement for introduction of nitrogen can be realized. COPYRIGHT: (C)2005,JPO&NCIPI