We activated 200 nm thick boron-doped crystalline silicon (c-Si) and polycrystalline silicon (poly-Si) layers at 1100 degrees C and examined the time dependence of the resistance of the layers with respect to subsequent processing steps at lower temperatures. The resistance of both c-Si and poly-Si does not change over time for a dose of 5 x 10(14) cm(-2). The resistance does increase with time and finally saturates, however, for the higher dose of 1 x 10(16) cm(-2). The onset time for this resistance increase of c-Si is much later than that of poly-Si. We have proposed a model that explains this resistance increase of both c-Si and poly-Si.