Transient enhanced diffusion and dose loss (pile-up) were investigated for P-implanted samples covered with both oxide and nitride films. Samples of p-type (100) Czochralski Si were implanted with 100keV P ions, to a dose of 5 x 1013/cm3, through a chemical vapor deposited Si3N4 film. In half of the samples, the Si3N4 was etched off and SiO2 films were grown by chemical vapour deposition. Both samples were annealed (700C, 20 to 360min). The diffusivity of P, and the dose loss, were estimated on the basis of secondary ion mass spectrometry P profiles. The Si/Si3N4 and Si/SiO2 interfaces were investigated using transmission electron microscopy and electron energy-loss spectroscopy. It was found that there was no significant difference in the P diffusivity between SiO2 and Si3N4 films for the present annealing conditions. A distinctly different behavior was observed with regard to dose loss. In case of a SiO2 covering film, the dose amount decreased with the annealing time. On the other hand, the dose amount decreased for annealing times of up to 3h, but then recovered at longer than 3h in the case of a Si3N4 covering film. Transmission electron microscopic and electron energy-loss spectroscopic data showed that N segregated at the Si/Si3N4 interface; thus resulting in the recovery of dose loss.

Effect of Nitrogen Segregation on TED and Loss of Phosphorus in CZ-Si. N.Fujiwara, K.Saito, Y.Nakabayashi, H.I.Osuman, K.Toyonaga, S.Matsumoto, Y.Sato: Nuclear Instruments and Methods in Physics Research B, 2002, 186[1-4], 313-7