Laser annealing induced high Ge concentration epitaxial SiGe layer in Si1-x Gex virtual substrate

Abstract

Graded silicon germanium (Si1-y Gey) epilayer with a thin layer of high Ge concentration (∼36%) near the surface is obtained by laser thermal annealing (LTA). The graded Si1-y Gey layer is formed during a liquid phase regrowth after LTA. The relaxation in this graded Si1-y Gey epilayer is insignificant; therefore it can be integrated into the source/drain of the p -type metal-oxide-semiconductor field effect transistor to induce high compressive strain to the Si channel. The thickness of the graded Si1-y Gey epilayer and the concentration of the Ge near the surface can be controlled by the laser fluence, which in turn changes the strain induced to the Si channel of strained devices. © 2008 American Institute of Physics.