Semiconductor device

Abstract

A first silicon layer (Si layer), a second silicon layer (Si1Cy layer) containing carbon and a third silicon layer not containing carbon are stacked in this order on a silicon substrate. Since the lattice constant of the Si1-yCy layer is smaller than that of the Si layer, the conduction band and the valence band of the second silicon layer receive a tensile strain to be split. Electrons having a smaller effective mass, which have been induced by an electric field applied to a gate electrode, are confined in the second silicon layer, and move in the channel direction. Thus, an n-MOSFET having extremely high mobility can be obtained. Furthermore, if the second silicon layer is made of Sil-x-yGexCy, a structure suitable for a high-performance CMOS device can be formed. A high-performance field effect transistor can be provided at lower costs by using a heterojunction structure mainly composed of silicon.

Dependencies are inferred from the claim text.