ATOMIC-LAYER EPITAXY CONTROL OF GE AND SI IN FLASH-HEATING CVD USING GEH4 AND SIH4 GASES

Initial growth stages of Si and Ge in flash-heating CVD using SiH4 and GeH4 gases were investigated, in order to control the atomic-layer he teroepitaxy. It was found that Si was deposited on the Ge surface even at substrate temperatures below 300-degrees-C without the flash shot, and the deposited Si thickness increased with increasing the SiH4 exp osure time and saturated to a single atomic-layer thickness with a lon ger time to reach saturation at a lower temperature in the range of 20 0-300-degrees-C. In the case of Ge growth on a wet-cleaned Si surface, an incubation period was observed even with the flash shot. By increa sing the flash light intensity and the GeH4 partial pressure, the incu bation period was reduced and a single atomic-layer growth of Ge on th e wet-cleaned Si(100) was achieved with a single flash shot at 275-deg rees-C.