Hj. Osten et al., OBSERVATION OF THE FORMATION OF A CARBON-RICH SURFACE-LAYER IN SILICON, Physical review. B, Condensed matter, 52(16), 1995, pp. 12179-12183
Due to its small size, the carbon atom has a very low solubility in a
silicon crystal. In spite of this, we show that carbon atoms adsorbed
on top of a silicon surface readily migrate into substitutional sites
below the surface, leading to a narrow layer of a highly concentrated
alloy. This was demonstrated by depositing carbon on a Si (001) surfac
e by molecular beam epitaxy and investigating the changes in the chemi
cal environment by x-ray photoelectron spectroscopy during successive
annealing steps at increasing temperatures. Ab initio total-energy cal
culations were used to interpret the measured spectra.