Dopant-enhanced H infiltration into surface amorphous Si layers formed by ion implantation was studied. Dopant-enhanced H in-diffusion was observed for both B and P implantation profiles in a-Si, and the effect of this enhanced in-diffusion upon the kinetics of solid-phase epitaxial crystallization was determined. Near-surface dopant profiles were produced by multiple-energy ion implantation. Annealing was performed in air at 500 to 640C. Secondary ion mass spectrometric analysis of partially annealed samples revealed that implanted dopants enhanced the in-diffusion of H, thereby increasing its concentration at depths well beyond the dopant-implanted region. The effect of an enhanced H concentration upon crystallization rates via solid-phase epitaxial crystallization was monitored using time-resolved reflectivity. Boron was found to enhance both H diffusion and solid-phase epitaxial crystallization to a much greater extent than did P.

Dopant Enhanced H Diffusion in Amorphous Silicon and its Effect on the Kinetics of Solid Phase Epitaxy. B.C.Johnson, P.Caradonna, J.C.McCallum: Materials Science and Engineering B, 2009, 157[1-3], 6-10

Table 28

Diffusivity of 2H2 in n-Type Si