Highly strained metastable structures and selective area epitaxy of Ge-rich Ge 1− xSi x/Si(100) materials using nanoscale building blocks

Abstract

Low-temperature heteroepitaxy (330 ∘C–430 ∘C) of Si 0.5Ge 0.5 and Si 0.25Ge 0.75 on Si(100) using single-source silyl-germanes [ SiH 3GeH 3,HSi(GeH 3) 3] produces monocrystalline structures, smooth and continuous surface morphologies and low defect densities. The metastable compressive strain in these films is dramatically enhanced relative to alternative growth methods. At such low temperatures the material grows seamlessly, conformally, and selectively in the “source/drain” regions of prototypical transistors. These results suggest that films grown via silyl-germanes could have applications in optoelectronics and as stressors for mobility enhancement in Si devices.