Effects of high temperature rapid thermal processing on oxygen precipitation in heavily arsenic-doped Czochralski silicon

Oxygen precipitation (OP) behaviors in heavily arsenic-doped Czochralski silicon wafers without and with prior rapid thermal processing at 1100-1250 °C, subjected to subsequent two-step anneal of 450, 650 and 800 °C/4 h+1000 °C/16 h, have been investigated. It is found that the prior RTP at 1250 °C substantially enhances OP in each two-step anneal. Such enhancement effect exhibits most significantly in the two-step anneal with the nucleation at 800 °C. However, in order to form the highest density of oxygen precipitates, the most desirable nucleation temperature is 650 °C in both cases without and with prior RTP. The OP nucleation mechanisms operating in the three low temperatures as mentioned above have been tentatively discussed.