HETEROEPITAXY OF SI1-XGEX LAYERS ON SI(100) SUBSTRATES FROM ATOMIC SIAND MOLECULAR GEH4 BEAMS

Heteroepitaxial layers of Si1-xGex(0.01 < x < 0.35) on Si (100) substr ates were grown by a new hybrid method at temperatures 600-850 degrees C from the atomic beams of silicon, obtained by sublimation and from the molecular how of GeH4 decomposing on the growth surface. The heter oepitaxial layers were grown at rates up to 20 nm/min under a GeH4 pre ssure ranging from 1 x 10(-6) to 1 x 10(-3) torr. The Ge concentration in heteroepitaxial layers increased at higher germane pressures and a t lower the growth rates. The mobility of electrons in heteroepitaxial layers coincided with mobility expected in bulk alloys with the same x values and carrier concentrations. On the graded alloy sublayer, the Si1-xGex/Si1-yGey superlattices with a period of 10-30 nm, x approxim ate to 0.1, and y approximate to 0.1-1 were grown.