Grown-in Defects Engineering by Nitrogen Doping in CZ-Si Crystals : Silicon(<Special Issue>Bulk Crystals for Human Activity in the New Millennium)

Abstract

Understanding and Controlling the nature of grown-in defects of Czochralski silicon crystals, especially octahedral void defects and oxygen precipitates, have been the key issue for silicon wafer industry to meet the drastic scaling down and integration of state of the art electronic devices in past three decades. We presented the nitrogen doping defect engineering which enables us to control both the voids and the oxygen precipitates simultaneously. By nitrogen doping, the morphology of the voids becomes plate shape triclinic and the size of the voids decreases, while the minute oxygen precipitates become already existent with high volume density in grown-in state crystals. Subsequent argon ambient annealing transforms the nitrogen doped wafers into ideal high performance wafers with stable defect free surface as well as subsurface zone for superior electric integrity and high density defect bulk region for strong impurity gettering ability. Implications for the mechanism of nitrogen effects are discussed.