The impact of nitrogen on power diode characteristics

The impact of nitrogen in Czochralski (CZ) silicon on the characteristics of power diodes has been studied. The nitrogen doped CZ silicon (NCZ) grown in a nitrogen atmosphere was used for manufacturing diodes. For comparison, the common CZ silicon (ACZ) grown in an argon ambient with almost the same oxygen concentration and thermal history was also used. It was found that more oxygen precipitates and higher density of dislocations were generated in the diodes produced by NCZ silicon, especially with high oxygen concentration. The reverse breakdown voltages (Vr) and the times of reverse recovery (Trr) of the diodes produced by NCZ silicon with higher oxygen concentration were slightly lower. However, Vr and Trr of the diodes produced from NCZ silicon with lower oxygen concentration were almost the same as those from CZ silicon. It can be speculated that nitrogen decreases the Trr and Vr of diodes through the enhancement of the formation of oxygen precipitates and dislocations, if the oxygen concentration in silicon is high (>1018 cm−3).