X-ray spectroscopic studies of organo-metallic vapor phase epitaxial growth

Chemical Vapor Deposition often occurs under conditions unsuitable for simultaneous monitoring using electron-based structural probes. This is due to the near-atmospheric pressure which exists during growth. While some work has been performed using optical probes, the typically high temperatures in the reactor vessel and the vastly longer wavelength of visible light versus the features being studied has hampered its utility as a structural probe. Over the past several years x-rays from synchrotron storage rings have been used to study the surface structure of growing materials. These studies have been primarily scattering studies. In this paper we explore the use of x-ray spectroscopic studies for the analysis of film growth. We have focused on three areas: the measurement of reactor vessel profiles using x-ray fluorescence; The measurement of gas-phase Extended X-ray Absorption Fine Structure (EXAFS), and the measurement of EXAFS of adsorbed species on the substrates.