He backscattering and infrared absorption studies of natural diamond containing high concentrations of implanted silicon

The depth distribution of Si ions implanted with an energy of 40 keV into natural diamond crystals at room temperature is measured using 1.8 MeV He ion backscattering. The process of SiC formation by ion implantation, and also after annealing at elevated temperatures, is studied by IR absorption. In the case of distributed ion energy (24 and 40 keV) the Si concentration profile obtained at a dose of about 2.5 x 1015 ions/cm2 was found to follow the predictions. At high doses (up to 4.4 x 1017 ions/ cm2) the average relative content of Si in the implanted layer is about 59%. Just after ion implantation, the layer containing the majority of the Si atoms is heavily disordered (amorphized). The crystalline SiC layer formation and structure ordering occur as a result of annealing at temperatures above 9000C. In addition, the annealing at 12000C is followed by considerable changes of the relation between the components C and Si in the implanted layer due to the migration of atoms. (author)