Formation of iron silicide thin films

The reaction of thin films of Fe with a silicon substrate to form iron silicides has been studied using Auger electron spectroscopy (AES) and electron energy loss spectroscopy. The formation of FeSi and FeSi2 is confirmed by comparison of plasmon losses with those reported for the bulk silicides. Changes in the Fe-AES spectrum upon silicide formation result primarily from changes in the plasmon losses. Changes in the AES intensity are correlated with the formation of the two silicide phases. FeSi forms during heating around 400 °C and is stable at temperatures up to 530 °C. Further heating results in the formation of FeSi2 at around 550 °C. This phase is stable up to 670 °C.