Dynamics and surface segregation during GSMBE of Si_(1-y)C_y and Si_(1-x-y)Ge_xC_y on the Si(001) surface

摘要

This paper reports on the study of the growth dynamics of Si and SiGe containing a small fraction of carbon from the hydrides of Si, Ge and methylsilane. Dynamic changes in the growth rate across heterojunctions show that the presence of carbon on the (001) surface of Si or SiGe supresses growth rate and the carbon concentration could not be changed abruptly at an interface due to the surface segregation of carbon during growth. Temperature programmed desorption of molecular hydrogen from the Si(001) surface with various adsorbates shows that the presence of carbon increases the barrier to the desorption of molecular hydrogen and reduces the sticking probability of disilane. Bath effects may lead to a reduction in the growth rate but the disilane supply rate (flux) dependence of growth rate on clean and carbon containing Si(001) surface shows that the primary cause of the growth rate decrease is the reduced sticking probability under the growth conditions used.