Abstract: The effect of rapid thermal annealing (RTA) ambient on denuded zone and oxygen precipitates in Czochralski (CZ) silicon wafers is studied in this paper.N2 and a N2/NH3 mixture are used as RTA ambient.It is demonstrated that a high density of oxygen precipitates and thin denuded zone are obtained in N2/NH3 ambient,while a relatively lower density of oxygen precipitates and thicker denuded zone are observed in N2 ambient.As the RTA duration times increased,the oxygen precipitate density increased and the denuded zone depth decreased.X-ray photoelectron spectroscopy (XPS) data and atomic force microscope (AFM) results show that there was a surface nitriding reaction during the N2/NH3 ambient RTA process,which can explain the different effect of RTA ambient.

Key words: 300mm CZ silicon wafer, denuded zone, intrinsic gettering, RTA, XPS, AFM