Formation and Characterization of Strained Si1-XGex Films Epitaxially Grown on Si(100) by Low-Energy ECR Ar Plasma CVD without Substrate Heating

For quantum-effect nano heterostructures of group IV semiconductors, formation and characterization of Si1-xGex films epitaxially grown on Si(100) by using low-energy electron-cyclotron-resonance (ECR) Ar plasma chemical vapor deposition (CVD) without substrate heating were investigated. Epitaxial Si0.50Ge0.50 films with smooth surface can be obtained on Si(100), where the thickness is almost proportional to deposition time and an incubation period is scarcely observed. For a 12 nm-thick epitaxial Si0.50Ge0.50 film on Si(100), its lattice constant in the direction perpendicular to the interface shows that the lattice is highly strained compared to a case of strain-relaxed Si0.50Ge0.50. This indicates that our ECR plasma CVD process has a potential to achieve highly strained heterostructures with suppressed strain relaxation and thermal interdiffusion at the heterointerface which are necessary for quantum-effect devices.