Determination of oxide precipitate phase and morphology in silicon and germanium using infra-red absorption spectroscopy

Oxide precipitates in single crystal silicon and in germanium lead to the formation of specific absorption bands in FTIR spectra. A novel methodology is used to interpret and simulate the FTIR spectra. It is based on the assumption that the optical response of the precipitates can be simulated by that of a mixture of two components with known optical properties. The effective dielectric function of such mixture depends on the way the two phases are mixed together. It is shown that both the volume fractions and the spectral functions can be obtained in the case of oxide precipitates in silicon and germanium.