Ion beam synthesis of diamond-SiC-heterostructures

Nanocrystals of silicon carbide were synthesized inside natural diamond using high dose silicon implantation. In order to retain the diamond structure implantation was done at 900 degreesC. The samples were subsequently annealed in an rf-heated furnace at 1500 degreesC for 10 min. X-Ray diffraction (XRD), IR absorption spectrometry and high-resolution cross-sectional transmission electron microscopy (HRTEM) are used to investigate formation and structure of SiC nanocrystallites in the implanted diamond. Raman spectroscopy contributed to trace implantation-induced destruction of the diamond. A first characterization of the electrical properties of the implanted and annealed samples is done by four-point probe measurements. The results indicate a highly conductive, buried layer inside the diamond. This layer contains cubic SiC nanocrystals, which are perfectly aligned with the diamond lattice. However, when fluence exceeds a critical value of 5.3 x 10(17) Si+ cm(-2), the diamond is irreversibly damaged and defect conduction type dominates. (C) 2002 Elsevier Science B.V. All rights reserved.