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 gr own on Si(100) by reactive deposition epitaxy using high vacuum evapor ation technique. This work is based on the idea that the band structur e of beta-FeSi2 will be changed with part of the Si atoms in the latti ce 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 t hat 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 measurement s, which indicate a redshift of the band gap with regard to that of be ta-FeSi2 (E(g)=0.87 eV) thin films. (C) 1996 American Institute of Phy sics.