Kozak A. The structure, optoelectronic and mechanical properties of thin Si-C-N films

In the thesis, the investigations of the optoelectronic, physical and mechanical properties of thin Si-C-N films were carried out. The films were produced by: i) plasma enhanced chemical vapor deposition (PECVD), using liquid precursor hexamethyldisilazane and ii) magnetron sputtering (MS) a silicon-carbon target in a nitrogen atmosphere. A comprehensive comparison of the properties of the films deposited by using both the methods was done. An effect of the peculiarities of inter-atomic interactions on mechanical and optoelectronic properties was studied. The electrical and photovoltaic properties of a-SiCN/c-Si heterojunctions were analyzed. It was established that all the deposited films were X-ray amorphous. The main chemical bonds in the films are Si-C, Si-N and C-N ones. PECVD thin films exhibit bright photoemission with the main peak in blue region of the spectrum. The intensity of this peak increases with increasing nitrogen. The value of optical energy gap of PECVD films is in the range of 1,05-2,4 eV and is sensitive to the deposition parameters. PECVD and MS films exhibit different dependences of nanohardness (H) and elastic modulus (E) on nitrogen flow rate. The values of H and E of PECVD films varied in the range of 8-34 GPa and 110-220, respectively, depending on the deposition parameters (flow of nitrogen, substrate temperature, discharge power). The analysis of the structure and mechanical properties of the annealed films indicates that the films are thermally stable up to temperatures above 1000 °C.