Recombination activity of nickel in nitrogen-doped Czochralski silicon treated by rapid thermal processing

The recombination activities of nickel (Ni) in p-type nitrogen-doped Czochralski (NCZ) silicon (Si) subjected to the rapid thermal processing (RTP) under different temperatures, atmospheres or cooling rates were investigated by means of microwave photoconductivity decay and scanning infrared microscopy. It was found that the value of the reciprocal of effective minority carrier lifetime (1/τeff) of NCZ Si, related to the recombination activity of Ni, increased with the annealing temperature or cooling rate, while, it was almost insensitive of the annealing atmosphere. Moreover, the 1/τeff of the Ni-contaminated NCZ Si was lower than that of the Ni-contaminated conventional Czochralski (CZ) Si annealed under the same condition. It is considered that the nitrogen-related defects or large grown-in oxygen precipitates might be the reason of relative lower recombination activity of Ni in NCZ Si.