SEMICONDUCTOR DEVICE AND FABRICATING METHOD THEREOF TO PREVENT SURFACE ROUGHNESS OF SiGe LAYER FROM INCREASING IN FORMING CAP SILICON LAYER ON SiGe LAYER

摘要

PURPOSE: A semiconductor device is provided to prevent the surface roughness of a SiGe layer from increasing in forming a cap silicon layer on the SiGe layer by forming the SiGe layer on a high dielectric layer such that the SiGe layer has no void to improve surface planarization. CONSTITUTION: A gate electrode includes a SiGe layer(10) that is formed on a substrate(2) by interposing a gate insulation layer(6). The gate insulation layer includes a base interface layer(6a) and a high dielectric layer(6b) having a higher relative dielectric constant than that of the base interface layer. The gate electrode includes a seed silicon layer(8) formed on the high dielectric layer and a SiGe layer formed on the seed silicon layer.