Special electrical properties of recrystallization of Ar plus -beam-induced amorphous silicon by laser annealing

Laser annealing is a specialized technology which is widely used in the activation of a variety of electroactive impurities. However, the special electrical properties of implanted inert impurities in semiconductors under laser annealing conditions were rarely studied. In this work, the recrystallization of amorphous silicon (a-Si) generated by Ar+ implantation annealed by laser thermal process (LTP) and rapid thermal process (RTP) were investigated. We found that massive cavities were created by LTP, while a recrystallization polycrystalline silicon (p-Si) layer with almost no defects can be obtained at the laser energy density of 1.5 J/cm2. We reveal a significant correlation between the presence of cavities and donor-like impurities by comparing the cross-sectional microstructures and electrical properties of samples after laser annealing and rapid thermal annealing. Energy band theory was conducted to account for the donor-like properties of cavities. In addition, the effect of phosphorus-argon co- implantation on the recrystallized layer of silicon laser annealing was explored. We found that the order of phosphorus and argon implantation in phosphorus-argon co-implantation has a significant effect on the recrystallized structure of the sample and we also explains the reason for argon pre-implantation in phosphorus- argon co-implantation and then undergoing laser annealing to generate special recrystallized structures. These findings provide new evidence for the donor-like nature of cavities in silicon, as well as new horizon for reflecting on pre-implantation of impurities.