The role of excess interstitials in the end-of-range region in transient enhanced diffusion of B during annealing of laser-processed samples was examined. The results showed that although the amorphous layer in pre-amorphized Si could be completely annealed by laser irradiation, the end-of-range damage was insufficiently annealed. The end-of-range region contained a supersaturation of interstitial defects that enhanced the diffusion of B during post-laser processing annealing. It was found that the transient enhanced diffusion was significantly suppressed when the melt depth was extended beyond the amorphous layer such that the interstitial dose in the region adjacent to the laser-melted layer was minimized. In this way, the abruptness of laser-processed ultra-shallow junctions could be maintained during further annealing at moderately high temperatures. Cross-sectional transmission electron microscopy showed that a virtually defect-free re-grown layer was obtained by over-melting beyond the amorphous layer into the substrate.

Control of Transient Enhanced Diffusion of Boron after Laser Thermal Processing of Preamorphized Silicon. Y.F.Chong, K.L.Pey, A.T.S.Wee, T.Osipowicz, A.See, L.Chan: Journal of Applied Physics, 2002, 92[3], 1344-50