Structural Comparison between Ge and GaAs Films Grown by Molecular Beam Epitaxy on Si Substrate

Abstract

Ge films with a linearly graded Si1-xGex buffer layer (0≦x≦1) and GaAs films have been grown by molecular beam epitaxy (MBE) on a Si(100) substrate. Both layers are compressed in the growth direction. In the case of Ge layers, the residual strain decreases whereas the surface roughness increases with an increase in thickness. The surface morphology of the Ge films displays a crosshatch pattern. In the case of GaAs layers, the residual strain increases and the surface roughness remains almost unchanged with an increase in thickness.