Gas source molecular beam epitaxy and thermal stability of Si1-x Gex/Si superlattice materials

Gas source molecular beam epitaxy has been used to grow Si1-x Gex alloys and Si1-x Gex/Si multi-quantum wells (MQWs) on (100) Si substrates with Si2H6 and GeH4 as sources. Heterostructures and MQWs with mirror-like surface morphology, good crystalline quality, and abrupt interfaces have been studied by a variety of in situ and ex situ techniques. The structural stability and strain relaxation in Si1-x Gex/ Si heterostructures have been investigated, and compared to that in the As ion-implanted Si1-x Gex epilayers. The results show that the strain relaxation mechanism of the non-implanted Si1-x Gex epilayers is different form that of the As ion-implanted Si1-x Gex epilayers. (Author)