Oxygen-implanted film material was subsequently implanted with BF2 to low or high doses and then annealed at various temperatures. Transmission electron microscopy, secondary ion mass spectrometry, and spreading resistance methods were used to analyze the resultant structures. It was found that a pile-up phenomenon occurred close to the upper surface of the film, and anomalous B diffusion was detected after low-dose BF2 implants. These observations were explained in terms of the quality of the film. The McNabb-Foster model for diffusion plus trapping was solved in order to interpret the effects. The redistribution of B after high-dose BF2 implants was the same for O-implanted films as for bulk Si.

P.Normand, D.Tsoukalas, N.Guillemot, J.Stoemenos: Journal of the Electrochemical Society, 1990, 137[7], 2306-13