Annealing effect on structural defects in low-dose separation-by-implanted-oxygen wafers

The annealing characteristics of low-dose separation-by-implanted-oxygen (SIMOX) (100) Si have been investigated by transmission electron microscopy (TEM). Samples are prepared by 60, 120, and 210 keV oxygen implantations with doses between 1.0 x 10(17) and 6.0 x 10(17)/cm(2) at 560 degrees C, followed by annealing at temperatures between 1000 and 1350 degrees C for 5 to 60 min in a vacuum of 10(-6) Torr. As-implanted layers split into two sublayers during high-temperature annealing. The shallow SiO2 precipitate region is located at around projected range (R-p)/2 instead of damage peak (D-p), while the deep buried oxide layer (BOX) lies at around R-p. Also, during the same annealing stages, cavities and SiO2 precipitates are produced and then dissolved in the near surface region above R-p/2. These experimental results are discussed, referring to the point defect distributions in the substrates obtained by Monte Carlo simulation.