Initial stages of C and Ge incorporation into Si(001) during heteroepitaxial chemical vapor deposition

he performance of heterostructured group IV semiconductor electronic and optoelectronic devices is partially dependent on the chemical composition of the heterostructure layers and interfaces. For this reason, it is vital to ascertain the initial chemical reactions that occur during Si;In this dissertation, I present an examination of the interaction of the precursor molecule with the top surface layer during group IV heteroepitaxy. To achieve analytical top layer chemical sensitivity in a functional CVD environment, I have developed extensions to the Fourier transform infrared - attenuated total reflection (FTIR-ATR) technique that facilitate in-situ analysis along with an extended spectral range. Using FTIR-ATR and reflection high-energy electron diffraction (RHEED), we have found that: (1) When a monolayer of Ge is deposited on Si (001) by UHV-CVD, and the surface is dosed with atomic hydrogen, a fraction of the Ge atoms undergoes a place exchange reaction with the silicon atoms in the second layer. A dimer vacancy migration assisted mechanism is proposed for this reaction. This process is monitored by in-situ FTIR-ATR spectroscopy, which is used as a surface composition analysis tool by "tagging" the surface species with atomic hydrogen. (2) The decomposition of t-butyl silane on Si (001) leads to C incorporation into the substrate. It is postulated that the decomposition pathway is dissociative chemisorption forming t-butylsilylene with the remaining two hydrogen atoms bonding at neighboring sites. As the sample temperature is increased, the majority of the adsorbed t-butylsilylene undergoes a...