Oxide precipitation behavior after rapid thermal annealing in Ar, N2 or O2 ambient was investigated. Lightly B-, N- or C-doped p-CZ Si wafers with a diameter of 200mm ([Oi]=11.5 x 1017 to 13.9 x 1017/cm3) were prepared as samples. The rapid thermal annealing temperature and cooling rate were changed between 1280 and 1200C, and between 70 and 5C/s, respectively. From the result of in Ar ambient, it was found that M-like depth profile of precipitate density was observed in the lightly B-doped wafer. The width of the precipitate-denuded zone (DZ) decreased in the N-doped wafer compared with the lightly B-doped wafer and the precipitate-denuded zone width in the C-doped wafer was comparable to that in a lightly B-doped wafer. From the calculated result of the depth profile of vacancy (V) and Si interstitial (I) concentrations, CV and CI, it was clarified that the relationships of thermal equilibrium concentration and the diffusion constant of point defects were to be CV* > CI* and DV < DI, respectively, to appear the M-like profile in lightly B-doped wafer. From the result of the decrease of the DZ width, it was deduced that the diffusion constant of vacancy decreased in the N-doped wafer. From the result of in lightly B-doped wafer in N2 or O2 ambient, it was found that (1) the precipitate density was higher compared with that in Ar ambient and (2) the precipitate was not observed in O2 ambient. These results due to the injection of the vacancy or the interstitial Si during rapid thermal annealing in N2 or O2, respectively.

Effect of Rapid Thermal Annealing on Oxide Precipitation Behavior in Silicon Crystal. M.Akatsuka, M.Okui, K.Sueoka: Nuclear Instruments and Methods in Physics Research B, 2002, 186[1-4], 46-54