SUBSTITUTIONAL VERSUS INTERSTITIAL CARBON INCORPORATION DURING PSEUDOMORPHIC GROWTH OF SI1-YCY ON SI(001)

Molecular beam epitaxial growth of Si1-yCy alloys pseudomorphically st rained on the (2x1) reconstructed Si(001) has been investigated as a f unction of growth conditions. An important question concerns the relat ion between substitutional and interstitial carbon incorporation, whic h has a large impact on electrical and optical properties of these lay ers. We show that the interstitial-to-substitutional carbon ratio is s trongly influenced by the growth conditions, such as growth temperatur e and Si growth rate. Both reduction in growth temperature and increas e of the overall growth rate lead to an increase in the substitutional -to-interstitial carbon ratio. However, these changes in growth condit ions can also cause some deterioration in crystal quality. The carbon incorporation behavior is well described by first order kinetics. (C) 1996 American Institute of Physics.