It was shown that an as-grown 15nm B-doped (2 x 1020/cm3) layer became unstable during annealing at above 650C for 600s. The thermal stability could be increased by performing 1MeV Si-ion implantation to 5 x 1015/cm2. The B profile after MeV implantation did not exhibit any significant diffusion during annealing at up to 750C. The final junction depth after annealing (800C, 600s) was about half that of an annealed non-implanted sample. Although, with MeV implantation, the B profile became slightly deeper due to recoil implantation (and some B was electrically deactivated by the MeV implantation), point-defect engineering was advantageous for post-growth thermal processes above 700C.

Using Point-Defect Engineering to Increase Stability of Highly Doped Ultra-Shallow Junctions Formed by Molecular Beam Epitaxy Growth. S.Lin, P.E.Thompson, J.Bennett, B.P.Dharmaiahgari, L.Trombetta, X.Wang, H.Chen, H.W.Seo, Q.Y.Chen, J.Liu, W.K.Chu: Applied Physics Letters, 2003, 83[14], 2823-5