The effects of surface proximity and B concentration upon end-of-range defect formation during non-melt laser annealing in pre-amorphized Si were studied. These effects were analyzed by observing the activation and diffusion of an ultra-shallow B implant, using Hall effect and secondary ion mass spectrometry measurements. By adjusting the pre-amorphizing implant and laser annealing conditions, B deactivation and diffusion were minimized. This was attributed to a combination of enhanced dissolution of end-of-range defects and preferential formation of B-interstitial clusters due to the surface proximity and high B The effects of surface proximity and B concentration upon end-of-range defect formation during non-melt laser annealing in pre-amorphized Si were studied. These effects were analyzed by observing the activation and diffusion of an ultra-shallow B implant, using Hall effect and secondary ion mass spectrometry measurements. By adjusting the pre-amorphizing implant and laser annealing conditions, B deactivation and diffusion were minimized. This was attributed to a combination of enhanced dissolution of end-of-range defects and preferential formation of B-interstitial clusters due to the surface proximity and high B