TRANSIENT GROWTH-RATE CHANGE DURING GAS-SOURCE MOLECULAR-BEAM EPITAXYOF SI1-XGEX ALLOYS

Reflection high-energy electron diffraction intensity oscillations dur ing gas source molecular beam epitaxy growth of Si1-xGex using disilan e and germane are reported. Transient changes of the oscillation perio d and hence the growth rate are observed during the growth. Their orig in is discussed on the basis of hydrogen desorption kinetics on the al loy surface and attributed to Ge surface segregation effects at the gr owth interface. This observation provides a unique opportunity for in situ investigations with monolayer-scale resolution, of Ge segregation effects in Si/Si1-xGex heterostructures.