A Study of Postannealing and in situ Annealing of Silicon Wafers Implanted with a High Dose of Oxygen

The effects of postannealing and in situ annealing on the reduction of oxygen ion implantation damage in silicon wafers were investigated by means of scanning electron microscopy, Rutherford backscattering spectrometry, and transmission electron microscopy. The results of this study, which utilized an etch-pit technique in conjunction with the SEM, showed that a high postannealing temperature (>1000/sup 0/C) was needed to effectively lower the imperfection density in the top surface region of silicon wafers. A postannealing time of 2h at a high temperature (>1000/sup 0/C) was sufficient to significantly reduce the implantation damage in the top silicon surface region. Finally, in situ annealing by wafer substrate heating during oxygen ion implantation was found to be more effective than postannealing at 1000/sup 0/C. A 10 ..mu..m epitaxial layer containing a low density of dislocations (about 5 x 10/sup 6/ dislocations/cm/sup 2/) was able to be grown onto the in situ annealed wafers.