VIBRATIONAL PROPERTIES OF SIO AND SIH IN AMORPHOUS SIOX-H FILMS (0-LESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-2.0) PREPARED BY PLASMA-ENHANCED CHEMICAL-VAPOR-DEPOSITION

The stretching and bending absorptions arising from SiO and SiH bonds in amorphous SiOx:H films, prepared by rf glow discharge-decomposition of a SiH4-O-2 mixture at 300 degrees C, have been investigated by infrared absorption measurements as a function of the O content, x. Changes in the profiles of the SiH stretching absorption as a function of x were examined on the basis of a random-bonding model. A charge-transfer model is employed to derive the oscillator strength of the SiH stretching absorption and the peak frequencies of the SiH and SiO stretching absorption, for the Si(Si4-nOn) (n = 1-4) and H-Si(Si3-nOn) (n = 0-3) bonding configurations. The absorption over the range 500-900 cm(-1), related to the SiH and SiO bending motions, can be decomposed into five components around 650, 780, 800, 840 and 880 cm(-1). It is found that the intensities of the 780, 840 and 880 cm(-1) bands are closely correlated with those of the SiH stretching absorptions at 2115, 2200 and 2260 cm(-1), respectively. The origins of these absorption bands along with the 650 and 800 cm(-1) bands are discussed.