Formation of carbon nanoclusters by implantation of keV carbon ions in fused silica followed by thermal annealing

In the last decade, the synthesis and characterization of nanometer sized diamond clusters have attracted growing interest within the scientific community. This is due to both scientific interest in the process of diamond nucleation and growth, the desire to investigate possible of quantum confinement effects and the fascinating technological applications in the fields of nanoelectronics and quantum communications and quantum computing. In past work [1, 2], our research group has demonstrated that MeV carbon ions implanted into fused quartz and subsequently annealed in the presence of hydrogen will form nanocrystalline diamond, with cluster size ranging from 5 to 40 nm. In the present work we report the synthesis of diamond nanocrystals by the implantation into fused silica of keV carbon ions using the Plasma Immersion Ion Implantation (PIII) technique, followed by thermal annealing in forming gas (4% H2 in Ar). The use of PIII technique has the advantage of allowing high dose-rate implantation on large substrates; such implantations can be patterned to design nanoelectronic devices based on diamond quantum dots. The samples have been characterized before and after annealing with optical absorption spectroscopy, visible and ultraviolet Raman spectroscopy, cross sectional Transmission Electron Microscopy (TEM), Electron Energy Loss Spectroscopy (EELS) and conducting Atomic Force Microscopy (AFM) in order to investigate the carbon phases as a function of the deposition parameters. The role of hydrogen in the nanodiamond formation process has been investigated with ion probe techniques, i.e. Secondary Ion Mass Spectroscopy (SIMS) and Elastic Recoil Detection Analysis (ERDA). The NV luminescence centers of diamond nanocrystals have a crucial role in the development of quantum computing devices with optical readout and in single photon sources. We report attempts to dope the diamond nanocrystallites with nitrogen by co-implantation with nitrogen and also by annealing in nitrogen containing ambients. References [1]: S. Prawer, J. L. Peng, J. O. Orwa, J. C. McCallum, D. N. Jamieson, L. A. Bursill, Phys. Rev. B 62, 16360 (2000) [2]: J. O. Orwa, S. Prawer, D. N. Jamieson, J. L. Peng, J. C. McCallum, K. W. Nugent, Y. J. Li, A. Bursill, S. P. Withrow, J. Appl. Phys. 90, 3007 (2001)