Origin and elimination of defects in SiO2 thermally grown on Czochralski silicon substrate

Oxide defect density for Czochralski Si (CZ-Si) substrates is found to be nearly one order of magnitude larger than that for float-zone Si (FZ-Si) substrates. The oxide defect density for CZ-Si substrates, subjected to an additional sacrifice oxidation, followed by etchback of the resultant oxides, is found to agree with that for FZ-Si substrates subjected to no special treatment. The origin of the oxide defects for CZ-Si is inferred to be metallic impurities originating from the substrates.