Spreading resistance measurements on nanocrystalline SiC produced by ion beam induced crystallisation

Ion beam induced crystallisation (IBIC) of preamorphised surface layers of 6H–SiC has been stimulated by high dose Al implantation (0.3−3×1017 cm−2) at elevated temperatures (300–500 °C) Randomly oriented 3C–SiC nanocrystals with diameters between 2 and 25 nm are formed depending on the implantation parameters as proved by XRD and XTEM. Spreading resistance measurements have been performed at bevelled as-implanted and annealed (1500 °C, 10 min) samples in order to study the electrical behaviour of the Al acceptors in the nanocrystalline layer. Reference experiments have been carried out on single crystalline 6H–SiC wafers implanted at the similar conditions. It has been found that in the as-implanted state Al doped fine granular SiC has much lower spreading resistance than the corresponding single crystalline SiC. Only minor differences have been observed between the nano- and single crystalline samples after annealing.