RF power effect on TEOS/O2 PECVD of silicon oxide thin films

The effect of the RF power at two excitation frequencies (13.56 and 27.12 MHz), on the growth rate and on the chemical composition of the deposited SiO2 films from TEOS/O2 discharges is investigated. The increase of RF power was found to significantly enhance the film growth rate up to an optimum and after that a slight decrease was observed, whereas for the same power level, the film growth rate at 27.12 MHz was always higher compared to 13.56 MHz. On the other hand, both hydroxyl groups and carbon content decreased with the increase of the discharge power while the increase of frequency was found to leave almost unaffected the number of hydroxyl groups and to reduce the Si-O bonded carbon.