A study of the diffusion of ion-implanted Sb, using Rutherford back-scattering spectrometry, showed that most of the implanted Sb was immobile during annealing in N2, O2 or O2/H2O ambients at temperatures as high as 1200C. When the oxide was encapsulated in Si3N4 during annealing, no diffusion at all was observed. In order to mobilize implanted Sb, extra O had to be supplied from the annealing ambient. The diffusion of Sb exhibited a lower (1.3eV) activation energy in a N2 or O2 ambient than that (2.3eV) in an O2/H2O ambient (table 119). The present results for an O2 ambient differed markedly from literature data, which gave an activation energy of 8.75eV and a pre-exponential factor which was 27 orders of magnitude lower than the value reported here. The diffusion of implanted Sb had some similarity to that of implanted As. There was evidence that the Sb was incorporated into both the Si and O sites of SiO2; as was As.

A.H.Van Ommen: Journal of Applied Physics, 1987, 61[3], 993-7

Table 119

Diffusion of Sb in SiO2