Abstract
Silicon-hydrogen ( SiH n , ( n=1, 2, 3)) bonding configurations in the very thin hydrogenated amorphous silicon (a-Si:H) films ( 4 dilution conditions have been investigated by means of infrared phase-modulated ellipsometry (IRPME). The silicon-hydrogen configurations are monitored as a function of film thickness for a variety of substrates and the various SiH4 dilution conditions of H2, Ar and He. The deposition thickness for SiH stretching mode become dominant is strongly influenced by the nature of the substrate and the SiH4 dilution conditions.