Semiconductor device and method of fabricating the same

Abstract

A gate electrode is formed on a semiconductor substrate with a gate insulating film interposed therebetween, and a sidewall spacer is then formed at the lateral sides of the gate electrode on the semiconductor substrate. Epitaxial growth is conducted at a lower growth rate to form, at both lateral sides of the sidewall spacer on the semiconductor substrate, first semiconductor layers made of first single-crystal silicon films superior in crystallinity. Then, epitaxial growth is conducted at a higher growth rate to form, on the first semiconductor layers, second semiconductor layers made of single-crystal films or polycrystalline films, which are inferior in crystallinity, or amorphous films. The upper areas of the first semiconductor layers and the whole areas of the second semiconductor layers are doped with impurity, thus forming impurity diffusion layers respectively serving as a source and a drain.