The formation of a denuded zone(DZ)by conventional furnace annealing(CFA)and rapid thermal annealing(RTA)based denudation processing is investigated and the gettering of copper(Cu)atoms in germanium co-doped heavily p...The formation of a denuded zone(DZ)by conventional furnace annealing(CFA)and rapid thermal annealing(RTA)based denudation processing is investigated and the gettering of copper(Cu)atoms in germanium co-doped heavily phosphorus-doped Czochralski(GHPCZ)silicon wafers is evaluated.It is suggested that both a good quality defect-free DZ with a suitable width in the sub-surface area and a high density bulk micro-defect(BMD)region could be formed in heavily phosphorus-doped Czochralski(HPCZ)silicon and GHPCZ silicon wafers.This is ascribed to the formation of phosphorus-vacancy(P-V)related complexes and germanium-vacancy(GeV)related complexes.Compared with HPCZ silicon,the DZ width is wider in the GHPCZ silicon sample with CFA-based denudation processing but narrower in the one with two-step RTA pretreatments.These phenomena are ascribed to the enhancing effect of germanium on oxygen out-diffusion movement and oxygen precipitate nucleation,respectively.Furthermore,fairly clean DZs near the surface remain in both the HPCZ and GHPCZ silicon wafers after Cu in-diffusion,except for the HPCZ silicon wafer which underwent denudation processing with a CFA pretreatment,suggesting that germanium doping could improve the gettering of Cu contamination.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 50832006 and 60906001the National Basic Research Program of China under Grant No 2007CB6130403,and the China Postdoctoral Science Foundation.
文摘The formation of a denuded zone(DZ)by conventional furnace annealing(CFA)and rapid thermal annealing(RTA)based denudation processing is investigated and the gettering of copper(Cu)atoms in germanium co-doped heavily phosphorus-doped Czochralski(GHPCZ)silicon wafers is evaluated.It is suggested that both a good quality defect-free DZ with a suitable width in the sub-surface area and a high density bulk micro-defect(BMD)region could be formed in heavily phosphorus-doped Czochralski(HPCZ)silicon and GHPCZ silicon wafers.This is ascribed to the formation of phosphorus-vacancy(P-V)related complexes and germanium-vacancy(GeV)related complexes.Compared with HPCZ silicon,the DZ width is wider in the GHPCZ silicon sample with CFA-based denudation processing but narrower in the one with two-step RTA pretreatments.These phenomena are ascribed to the enhancing effect of germanium on oxygen out-diffusion movement and oxygen precipitate nucleation,respectively.Furthermore,fairly clean DZs near the surface remain in both the HPCZ and GHPCZ silicon wafers after Cu in-diffusion,except for the HPCZ silicon wafer which underwent denudation processing with a CFA pretreatment,suggesting that germanium doping could improve the gettering of Cu contamination.
