Effect of annealing atmosphere on oxygen precipitation and formation of denuded zone in Czochralski silicon wafer

Abstract

In this paper, the effect of annealing atmosphere on oxygen precipitation and formation of denuded zone (DZ) in Czochralski (CZ) silicon has been investigated. It was revealed that the high-temperature annealings in various atmospheres resulted in almost identical oxygen outdiffusion length but different widths of DZ in the silicon wafers. It was confirmed that the high-temperature annealing in nitrogen atmosphere induced a high concentration of vacancies in silicon to enhance oxygen precipitation, while the annealing in oxidizing atmosphere or steam-mixed atmosphere induced a high concentration of silicon self-interstitials to retard oxygen precipitation. Moreover, it was confirmed that the steam mixed into the nitrogen atmosphere could suppress the indiffusion of nitrogen atoms. © 2006 WILEY-VCH Verlag GmbH & Co. KGaA.