Oxygen precipitates in annealed CZ silicon wafers detected by SIRM and FTIR spectroscopy

A scanning infrared microscope, a Fourier transform infrared spectrometer, and chemical etching have been associated with detecting precipitates in annealed Czochralski (Cz) silicon wafers and with controlling their interaction with self-interstitials injected into the bulk by phosphorus diffusion or by oxidation. After nucleation (750°C) and/or growth (900°C) annealing, phosphorus diffusion at 900°C for 4 h shrinks the precipitates revealed by SIRM, owing to a marked injection of self-interstitials in the bulk. Annealing of the two-step annealed samples in oxygen produces a similar effect; however, new defects are detected by SIRM which are identified as stacking faults.