GE SURFACE SEGREGATION AT LOW-TEMPERATURE DURING SIGE GROWTH BY MOLECULAR-BEAM EPITAXY

The temperature dependence of germanium surface segregation during gro wth by solid source SiGe molecular beam epitaxy (MBE) was studied by x -ray photoelectron spectroscopy and kinetic Monte Carlo (KMC) modeling . Germanium segregation persisted at temperatures 60-degrees-C below t hat predicted by a two-state exchange model. KMC simulations, where fi lm growth, surface diffusion, and surface segregation are modeled cons istently, successfully describe the low temperature segregation of ger manium. Realistic descriptions of MBE must follow the physical rates o f the growth, surface diffusion, and surface segregation processes.