Abstract: A ramping anneal,i.e.,the isothermal anneal at an elevated temperature of 1150℃ ramped up from a starting temperature (600~1000℃) was employed to enable the growth of the grown-in oxygen precipitates that are larger than the critical size at the starting temperature.Flourier transformation infrared spectroscopy and scanning infrared microscopy are used to measure the amount of precipitated oxygen and the oxygen precipitate density in a 300mm nitrogen-doped Czochralski silicon wafer,respectively.The grown-in oxygen precipitate density in the abnormal oxygen precipitation region (generally referred to as the P-region) is much higher than that in the vacancy-type defect region (generally referred to as the V-region).Moreover,the size distribution of grown-in oxygen precipitates in the V-region is not continuous,exhibiting large precipitates formed at high temperatures and small ones formed at low temperatures;while the grown-in oxygen precipitates in the P-region are continuously formed from high to low temperatures,thus leading to a continuous size distribution.Such results are tentatively explained in terms of the formation mechanisms for grown-in oxygen precipitates generated in the V- and P-regions.

Key words: 300mm nitrogen-doped Czochralski silicon wafer, grown-in oxygen precipitates, radial distribution