Infrared Spectra of Amorphous Silicon-Fluorine Alloys Prepared by Sputtering in Fluorosilane-Argon Gas Mixture

Infrared spectra of amorphous Si : F alloys prepared by sputtering of a silicon crystal in SiF4 or a mixture of SiF4+Ar were measured in the frequency range of 450–4000 cm-1. Six absorption bands were observed in the 800–1100 cm-1 region. These bands are assigned as the SiF N (N=1, 2, 3) bond stretching vibration modes by comparison with the infrared spectra of SiF N H4-N molecules. In addition, fluorine modified or enhanced Si-Si bond stretching modes were observed at 515 and 650 cm-1.