Silicon carbide and boron carbide thin films formed by plasma immersion ion implantation of hydrocarbon gases

Samples of silicon wafers and boron films on silicon were immersed in RF plasmas of methane and toluene. They were pulse-biased at different pulse durations and repetition rates at voltages up to − 45 kV. After the process, the samples were analyzed by Rutherford Backscattering Spectrometry for their composition, and by X-ray diffraction for their microstructure. The results show that under all conditions the silicon carbide and the boron carbide films were amorphous. The carbon depth profile depended on the process parameters, mainly on the number of applied pulses and the pulse repetition rate. The carbon implantation process was accompanied by deposition of a carbon film as a concurrent process. While in the case of toluene the deposition process dominated, in the case of methane it was possible to implant carbon in depth. The implantation process could be enhanced by increasing the pulse repetition rate.