IN-SITU OBSERVATION OF SILICON HYDRIDES AN SI(100) SURFACES DURING SYNCHROTRON-RADIATION-STIMULATED SI2H6 GAS-SOURCE MOLECULAR-BEAM EPITAXY

Silicon hydrides (SiHn) on the Si(100) surface during synchrotron-radi ation (SR) stimulated Si2H6 gas source molecular beam epitaxy has been observed in situ at low temperatures (less than or equal to 400 degre es C), by means of infrared reflection absorption spectroscopy using C oSi2 buried metal layer substrates. At high temperatures (400 degrees C, 370 degrees C), SiH is a dominant surface species, while with tempe rature decrease from 275 to 50 degrees C, the number of SiH decreases, and, on the other hand, SiH2 and SiH3 appear and increase. This resul t explains the change of reflection high-energy diffraction pattern fr om 2X1 to 1X1. The SiH in the bulk network has not been observed. SR i rradiation on the film at 140 degrees C after deposition shows that Si H2 and SiH3 are easily decomposed to SiH and that SiH decomposes much more slowly than SiH2 and SiH3. (C) 1995 American Institute of Physics .