Declustering and melting threshold study in laser irradiated Si(As)

Abstract

The sheet resistivity of 40-keV, 1016 As/cm2- implanted Si decreases by a factor of 3 after irradiation with a suitable energy density of Nd:YAG laser at 1.06 or 0.53 μm. The changes in conductivity occur with the melting and quenching of the surface layer as indicated by profile broadening, and they are associated with the declustering process during solidification. The threshold energy density for melting is studied. At 0.53 μm, the threshold is the same (∼0.4 J/cm2) for both as-implanted and thermally preannealed Si. At 1.06 μm, the threshold for the as-implanted sample is ∼5 J/cm2, while the threshold for the preannealed sample is ∼10 J/cm2. These results are in agreement with the absorption changes due to crystalline structure alterations and dopant.