Photoepitaxy of Si and Ge by synchrotron radiation

The correlating growth kinetics and crystal structures are described for synchrotron-radiation-excited Si and Ge epitaxy from Si2H6 and GeH4. The characteristics of growth mediated by photon-stimulated hydrogen desorption from irreversibly chemisorbed surface hydrides are distinguished from those due to photolysis of the reactants in the gas-phase and at the surface. For Si homoepitaxy on Si(100), it is shown how the morphology of the Si layer changes with the migration length of adatoms. For Ge homoepitaxy on Ge(100), a novel p(2×2) surface structure is observed when low-temperature deposition is followed by solid-phase epitaxy. The surfactant effect of hydrogen atoms results in uniform heteroepitaxy of Si on Ge(100) and Ge on Si(100), which enables nonthermal growth of SiGe multilayers.