BORON INCORPORATION IN SI1-XGEX FILMS GROWN BY ULTRAHIGH-VACUUM CHEMICAL-VAPOR-DEPOSITION USING SI2H6 AND GEH4

Abstract

0.1% B2H6 diluted in hydrogen is used as the p-type dopant gas in Si1-xGex grown by ultrahigh vacuum chemical vapor deposition (UHVCVD) using Si2H6 and GeH4. The boron concentration is evaluated by secondary ion mass spectrometry (SIMS). The boron concentration of Si1-xGex increases with the increase of the GeH4 flow rate, that is, Ge fraction, by keeping Si2H6 and B2H6 how rates constant. The result may be due to the increase of the vacant surface sites which is caused by the increase of the hydrogen desorption rate when a higher Ge fraction epilayer is grown. (C) 1995 American Institute of Physics.