Aluminum multiple implantations in 6H–SiC at 300 K

A complete study was driven in order to elaborate a p⁺–n junction in 6H–SiC. The chosen techniques were aluminum multiple implantations, followed with high-temperature furnace annealings. First, we had to configure the furnace geometry aiming at optimizing the annealed material characteristics. We evidenced the beneficial effects of a SiC plate inside the furnace reactor on the surface stoichiometry of the annealed sample, and also on its crystal reordering velocity. Then, the fivefold aluminum implantation necessary for the 0.5 μm depth p⁺-region creation has been studied, especially the energy order influence on the junction steepness. It was found that the increasing energy order implantations lead to a channeling effect less important, a deeper amorphized zone, and a defect interface at volume more abrupt. After an annealing performed with the optimized furnace, the best electrical activation obtained equated the degree of ionization even though the as-implanted material was totally amorphized up to 0.25 μm. Moreover, the three different multiple implantations investigated during this study induced different amorphized layer depths, despite they all have the same total aluminum dose with the same highest energy value. All along the paper, we propose to explain this fact. This is probably due to distinct mechanisms involved in the amorphization phenomena, which were tentatively estimated with a specific Monte Carlo simulator recently developed.