Ion Beam Synthesis of SiC-Diamond-Heterostructures

Both, silicon carbide (SiC) and diamond are wide band gap semiconductors with excellent electronic properties. Unfortunately, there has been only limited success in producing n-type regions in diamond or p-type regions in SiC. On the other hand, n-type doping of SiC by nitrogen (N) implantation and p-type doping of diamond by boron (B) implantation are well-established processes. Therefore, it is an obvious idea to combine the materials in order to exploit this complementary behavior for the fabrication of p-n-heterojunctions or n-type regions in insulating diamond. Preliminary experiments have shown that ion beam synthesis could be a suitable process for the production of SiC-diamond-heterostructures in microscopic regions. There are two ways to achieve these heterostructures: (i) diamond formation by high dose carbon (C) implantation in crystalline SiC and (ii) SiC formation by high dose silicon (Si) implantation in natural diamond. The implantation must be carried out at elevated temperatures (> 700°C) in order to avoid accumulation of implantation damage. Epitaxial, nm-sized diamond or SiC precipitates with spherical or platelike shape, respectively, are formed inside the host crystals by the ion beam synthesis.