Methods for stressing semiconductor material structures to improve electron and/or hole mobility of transistor channels fabricated therefrom, and semiconductor devices including such structures

摘要

Semiconductor material strips are secured to substrates in such a way as to stress the semiconductor material. The strips of semiconductor material may be compressively stressed, subjected to tensile stress, or some strips may be compressively stressed while other strips are tensilely stressed. Stress may be induced by forming non-planarities on the surface of the substrate to which the strips are to be secured. The non-planarities may be configured to stress strips of semiconductor material as the strips are secured thereover and over an intervening surface of the substrate, or to stress strips as the non-planarities are removed from beneath the strips. The strain that ultimately results from stressing the strips improves carrier mobility (i.e., electron mobility, electron hole pair, or "hole," mobility) relative to the carrier mobilities of unstrained semiconductor materials. The strained strips of semiconductor material may be used in the fabrication of semiconductor device structures such as transistors.