Boron-doped diamond is a material with a great technological and industrial interest because of its exceptional chemical, physical and structural properties. At modest boron concentrations, insulating diamond becomes a p-type semiconductor and at higher concentrations a superconducting metal at low temperature. The most conventional preparation method used so far, has been the homogeneous incorporation of boron doping during the diamond synthesis carried out either with high-pressure sintering of crystals or by chemical vapour deposition (CVD) of films. With these methods, high boron concentration can be included without distorting significantly the diamond crystalline lattice. However, it is complicated to manufacture boron-doped microstructures. A promising alternative to produce such microstructures could be the implantation of focused high-energy boron ions, although boron fluences are limited by the damage produced in diamond. In this work, the effect of focused high-energy boron ion implantation in single crystals of diamond is studied under different irradiation fluences and conditions. Micro-Raman spectra of the sample were measured before and after annealing at 1000°C as a function of irradiation fluence, for both superficial and buried boron implantation, to assess the changes in the diamond lattice by the creation of vacancies and defects and their degree of recovery after annealing.

The authors wish to thank the technical staff of CMAM for operating the tandem accelerator and the Ministerio de Economía y Competitividad (MINECO) for funding this work (Projects MAT2014-54826-C2-1-R, MAT2014-57547-R and FIS2014-54498-R). Research by NG is supported by the MINECO under the project JCI-2012-12652. MINECO/ICTI2013-2016/MAT2014-57547-R MINECO/ICTI2013-2016/FIS2014-54498-R