Instantaneous annealing of CVD diamond during high dose-rate ion implantation

A novel method of performing hot implantations into CVD diamond films is described. Sample heating during the implantation is achieved by utilizing the high power delivered to the sample by a high-current ion beam (up to 500 mu A cm(-2)) used for the implantation. Temperatures of about 1100 degrees C can be achieved by this method, thus avoiding the need for post-implantation annealing. It is shown by SIMS profiling, Raman spectroscopy and electrical resistivity measurements that: (1) when implantation starts from room temperature, a graphitic layer forms which when removed leaves a highly doped layer at the diamond surface; and (2) when implantation is started on a preheated sample (also by the ion beam) a highly doped layer located at the position of the ion range is obtained. The material thus obtained is highly conductive (over-doped) and exhibits variable range hopping. The material is very suitable for the realization of ohmic contacts to semiconducting diamond and for the formation of new carbon-based alloys. (C) 1999 Elsevier Science S.A. All rights reserved.