Investigation of titanium germanide formation by Raman scattering and x-ray absorption spectroscopy

This paper reports on the reactions of titanium on germanium that were studied using Raman spectroscopy and X-ray Absorption Spectroscopy (XAS). Samples used in this study were produced in a custom MBE system with dual E-gun sources, two filament sources, and base pressure <1 x 10-10 Torr. Ge(100) substrates were prepared by chemical cleaning and homoepitaxial deposition of 500 Angstrom--1000 Angstrom Ge at 550 degrees C. Ti was deposited and subsequently annealed at 50 degrees C intervals from 500 degrees C to 700 degrees C. Raman and XANES spectra of the titanium germanides were obtained and used to examine the evolution of the crystalline structures which form by the interface reactions of Ti on Ge. low-order phase formed by diffusion controlled growth prior to the formation of TiGe2 (isomorphous with TiSi2 [C54]) by nucleation controlled growth