The B lattice location of B implanted into crystalline Si at room temperature was investigated using the nuclear reaction 11B(p,α)8Be induced by 650keV proton beam and channelling analyses. The angular scans along the <100> and <110> axes indicated the formation of a particular B complex with B atoms non-randomly located. The same defect was observed also for B doped Si where the B atoms, initially substitutional and electrically active, were displaced as consequence of the interaction with the point defects generated by proton irradiation. The angular scans were compatible with the B–B pairs aligned along the <100> axis predicted by theoretical calculations. The thermal evolution of the B complexes in the 400 to 950C range was inferred both by B lattice location measurements and electrical activation. At low temperature (<700C) only 10% of the total B dose was active and a significant increase of randomly located B occurred. A significant electrical activation consistent with the concentration of substitutional B occurred at temperature higher than 800C. The data were interpreted in terms of a formation and dissolution of the B complexes.

B Implanted at Room Temperature in Crystalline Si - B Defect Formation and Dissolution. L.Romano, A.M.Piro, S.Mirabella, M.G.Grimaldi: Materials Science and Engineering B, 2005, 124-125, 253-6