Articles you may be interested inStudy of millisecond laser annealing on recrystallization, activation, and mobility of laser annealed SOI doped via arsenic ion implantation

Few transmission electron microscopy ͑TEM͒ studies of single crystal diamond have been reported, most likely due to the time and difficulty involved in sample preparation. A method is described for creating a TEM cross section of single crystal diamond using a focused ion beam and in situ lift-out. The method results in samples approximately 10 m long by 3 m deep with an average thickness of 100-300 nm. The total time to prepare a cross-sectional TEM sample of diamond is less than 5 h. The method also allows for additional thinning to facilitate high resolution TEM imaging, and can be applied to oddly shaped diamond samples. This sample preparation technique has been applied to the study of ion implantation damage in single crystal diamond and its evolution upon annealing. High-pressure-high-temperature diamonds were implanted with Si + at an energy of 1 MeV and a temperature of 30°C. One sample, with a ͑110͒ surface, was implanted with a dose of 1 ϫ 10 14 Si cm −2 and annealed at 950°C for 10 and 40 min. No significant defect formation or evolution was discernible by cross-sectional transmission electron microscopy. Another sample, with a ͑100͒ orientation, was implanted with 1 MeV at 1 ϫ 10 15 Si cm −2 and annealed at 1050°C for 10 min. Prior to annealing, a heavily damaged but still crystalline region was observed. Upon annealing, the sample showed no signs of conversion either to an amorphous form of carbon or to graphite. This is unexpected as the energy and dose are above the previously reported graphitization threshold for diamond. Higher annealing temperatures and possibly a high vacuum will be required for future study of defect formation, evolution, and phase transformations in ion-implanted single crystal diamond.

End of range ͑EOR͒ defects are the most commonly observed defects in ultrashallow junction devices. They nucleate at the amorphous-crystalline interface upon annealing after amorphization due to ion implantation. EOR defects range from small interstitial clusters of a few atoms to ͕311͖ defects and dislocation loops. They are extrinsic defects and evolve during annealing. Li and Jones ͓Appl. Phys. Lett., 73, 3748 ͑1998͔͒ showed that ͕311͖ defects are the source of the projected range dislocation loops. In this article, the same theory is applied to EOR dislocation loops to model the nucleation and evolution of the loops. The model is verified with experimental data and accurately represents the nucleation, growth, and Ostwald ripening stages of dislocation loop evolution. The density and the number of interstitials trapped by dislocation loops are compared with the experimental results for several annealing times and temperatures.

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Amorphization commonly occurs during implantation forming end o f range (EOR) defects at the amorphous/crystalline (dc) interface upon annealing. It is imperative to know how these defects form in order to do predictive simulations of dopants. In this study, we developed a model to predict the EOR defect nucleation and evolution. It is assumed that all the loops come from unfaulted (31 1)'s [l].: The model is verified with the new experimental results obtained by studying the formation of EOR defects by vaiying the implant energy from 40keV to 8OkeV at a dose of 2x10" ern-'.