A study on the structural characterization of a-SiC:H films by the gas evolution method

Abstract

Using a modified gas chromatograph, gas evolution experiments have been performed on hydrogenated amorphous silicon carbide (a-SiC:H) films with different carbon contents prepared by plasma deposition, to obtain information concerning the structure as well as the exodiffusion kinetics. The hydrogen bonding has also been characterized by infrared (IR) absorption measurements. In the hydrogen-evolution spectra, the height of the low-temperature (LT) peak and its temperature increase with an increasing carbon content in the films. From the results of gas evolution coupled with the IR absorption data, it is found that the hydrogen evolution from a-SiC:H films involves two processes: one is related to microvoids and/or polyhydride bonding, and the other is related to the dense network structure. The activation energies for hydrogen evolution in a-Si:H and a-Si 0.9C 0.1:H film are obtained by the thermal analysis technique, and are found to be as follows; 79KJ mol −1 and 112 KJ mol −1 for a-Si:H, and 85 KJ mol −1 and 163 KJ mol −1 for a-Si 0.9C 0.1:H for LT and HT peaks, respectively.