Fullerene freejets-based synthesis of silicon carbide: heteroepitaxial growth on Si(111) at low temperatures

Abstract

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 (Supersonic Molecular Beam Epitaxy, SuMBE) for the heteroepitaxial growth of SiC on Si by means of supersonic molecular beams of fullerene (C 60). The carbide synthesis can be induced by the kinetic activation of the process due to the kinetic energy released in C 60–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 C 60 supersonic beam. Two films were grown in Ultra High Vacuum (UHV) on Si(111)-7×7, at substrate temperature of 800 °C, using the same fullerene beam but selecting C 60 particles having different characteristics. Surface electronic and structural characterizations 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.