ABSTRACTThe reverse annealing of ion implanted boron, namely, the decrease in the concentration of electrically active boron as the isochronal annealing temperature increases, occurs in the temperature range from 550 to 650°C during conventional furnace heating. In this study, silicon crystals were boron implanted at 50 Kev to a dose of 1×1015 cm-2 followed by both furnace and tungsten-halogen lamp annealing in the reverse annealing temperature range. Cross-sectional Transmission electron microscopic (TEM) technique was used to examine the microstructural changes during annealing as a function of depth. Sheet resistance measurements gave a quick check of the electrical properties, while spreading resistance profiling with shallow angle lapping and Hall measurements reveals the mobility and carrier concentration as a function of depth. Czochralski and Float Zone crystals were studied to examine the effect of oxygen. Tungsten-halogen lamp thermal processing was found to have a more pronounced effect on the annealing of secondary defects than did furnace annealing. The reverse annealing of boron was eliminated completely for lamp annealing time as short as 60 seconds.