Fullerene Freejets-Based Synthesis of Silicon Carbide: Heteroepitaxial Growth on Si(111) At Low Temperatures

The growth of Silicon Carbide (SiC), a large band-gap semiconductor, on Si is very promising for applications to sensors, electronics and optoelectronics. However, difficulties in controlling the growth of the material and the interface have inhibited the production of SiC based devices. We have developed a new technique (SuMBE) for the heteroepitaxial growth of SiC on Si by means of supersonic molecular beams of fullerene (C60). The carbide synthesis can be induced by the kinetic activation of the process due to the kinetic energy released in C60-Si collision. This has made possible a reduction of the growth substrate temperature and an improvement of electronic and structural properties of the SiC film. We present a study of the processes governing the growth of very thin SiC film by C60 supersonic beam. Two films were grown in Ultra High Vacuum on Si(111)-7x7, at substrate temperature of 800°C, using the same fullerene beam but selecting C60 particles having different characteristics. Surface electronic and structural characterisations were done both in-situ and ex-situ. The results show that strongly different growth processes can be achieved by controlling the precursor kinetic energy.