Semiconducting Ge-Si-Fe alloy grown on Si(100) substrate by reactive deposition epitaxy

In this letter, we report a semiconducting Ce-Si-Fe alloy thin film grown on Si(100) by reactive deposition epitaxy using high vacuum evaporation technique. This work is based on the idea that the band structure of beta-FeSi2 will be changed with part of the Si atoms in the lattice replaced by Ge atoms. An iron film was first deposited on a SiGe/Si(100) structure, then the alloy was formed during an annealing process. Auger electron spectroscopy and x-ray diffraction results indicate that the new alloy film can be regarded as a distorted beta-FeSi2 thin film with the participation of Ge. The direct band gap of the Ge-Si-Fe alloy is determined to be 0.83 eV by optical transmission measurements, which indicate a redshift of the band gap with regard to that of beta-FeSi2 (E(g)=0.87 eV) thin films. (C) 1996 American Institute of Physics.