Studies of Sn+ pre-amorphized p+n junctions revealed the presence of some 1017/cm3 of deep-level donors after amorphous layer re-growth at temperatures below 800C. Removal of the defects by annealing at 800C permitted the leakage current which was associated with these defects to be distinguished from that which was due to dislocation loops at the amorphous/crystalline boundary. In both cases, the defects and leakage currents were similar to those which resulted from Si+ pre-amorphization. For a given Sn+ pre-amorphization treatment, the leakage current which was measured in substrates doped to 4 x 1013/cm2 was about 1000 times lower than in substrates which had been doped to 1016/cm2. When compared with Si+ pre-amorphization, the use of Sn resulted in a greater enhancement of B diffusion within the re-grown amorphous layer itself.

J.R.Ayres, S.D.Brotherton, J.B.Clegg, A.Gill, J.P.Gowers: Semiconductor Science and Technology, 1989, 4[5], 339-407