SEMICONDUCTOR DEVICE AND ITS MANUFACTURING METHOD

摘要

PURPOSE: A semiconductor device and its manufacturing method are provided to suppress fluctuations in the threshold voltage and improving a switching rate in a short channel MISFET. CONSTITUTION: The manufacturing method comprises, upon formation of a MISFET having a gate length not greater than about 0.1 mum, forming a first conductivity type impurity layer having a first peak in impurity concentration distribution and another first conductivity type impurity layer having a second peak in impurity concentration distribution in a substrate; forming source and drain extension regions of a second conductivity type in the substrate after formation of a gate electrode; and forming source and drain diffusion regions of the second conductivity type in the substrate after formation of side wall spacer on the side walls of the gate electrode.