Invited talk abstract

Controlled doping of bulk crystals and epitaxial layers of SiC can be performed in-situ during growth, and for instance, using chemical vapour deposition dopant concentrations over a wide range are accessible. However, for genuine SiC device processing a planar technology enabling selective area doping is required. In principle, ion implantation is ideally suited for this because of the possibility to accurately control the distribution of dopants in three dimensions without chemical or thermodynamical constraints. A major drawback is, however, the generation of damage destroying the crystalline structure of the implanted layer. The damage can vary from point defects caused by single collision cascades at low ion doses to amorphization at high enough doses. Post-implant annealing is thus necessary to restore the crystal structure and electrically activate the implanted dopants as shallow acceptors or donors.

For SiC, our knowledge and understanding of the damage build-up during implantation is severely limited and the same is true for the post-implant annealing processes. In this contribution, a survey is given of the current status, and issues like implantation temperature, defect evolution as a function of dose and dose rate, dopant compensation, co-implantation and electrical activation of dopants, evolution of structural defects during post-implant annealing, and transient enhanced dopant diffusion are addressed. Finally, recent results regarding the interaction between hydrogen and p-type dopants will be discussed.