Ion-channeling and Raman scattering study of damage accumulation in silicon

Damage was introduced into Si(100) using 245 keV Si+ ions implanted to a wide range of doses with implant temperatures of -195, 25 or 100 degreesC. The accumulation of this damage was monitored with Rutherford backscattering and ion channeling (RBS-C) and by following the intensity and lineshape variation of the first-order (1-O) Raman peak of silicon. For all implant temperatures the RBS-C data showed the expected trend with dose. For -195 degreesC and room temperature implants, the decrease in intensity of the 1-O Raman peak shows a similar trend to the RBS-C data, but in each case the threshold dose is about a decade lower than its RBS-C counterpart. On implantation at 100 degreesC the sensitivity of the Raman spectra to low damage concentrations is more dramatic and decreases continuously over the full dose range, from 5x10(12) to 2x10(16) Si/cm(2), examined in this study. This suggests that the intensity of the 1-O Raman peak is particularly sensitive to the types of defect structures that are stable in silicon during irradiation at elevated temperatures. The phonon confinement model is discussed in light of these results. (C) 2004 American Institute of Physics.