OXYGEN PRECIPITATES IN ANNEALED CZ SILICON-WAFERS DETECTED BY SIRM AND FTIR SPECTROSCOPY

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