Effects of electron deep traps on generation lifetime in denuded zone of <i>n</i>-type Si wafer

Abstract

The effects of electron deep traps on generation lifetime in heat-treated n-type Czochralski-grown (111) Si were examined by generation lifetime and deep level transient spectroscopy measurements. An order of magnitude increase in generation lifetime was observed for the samples having denuded zone, which experienced the high/low heat treatment (20 h at 1100 °C+16 h at 750 °C). Deep electron traps at Ec − 0.47, 0.42, 0.39, and 0.30 eV occur in the oxygen precipitated region by heat treatment. Especially, the concentration of the Ec − 0.47 eV trap decreased below 5×1012 cm−3 in denuded zone. From these results, we conclude that enhancement of generation lifetime in denuded zone may be dominantly related to the decrease of concentration of the Ec − 0.47 eV trap.