Transfer of thin Si layers by cold and thermal ion cutting

We have used the crack opening method to study the mechanical exfoliation behaviour in hydrogen implanted and bonded Cz Si. We found out that the crystal orientation and boron doping influence the temperature required for mechanical layer transfer. The boron implantation at doses >1013 cm-2 reduces the annealing temperature needed for mechanical exfoliation. The boron doped epilayers followed similar exfoliation behaviour as the boron-implanted samples. No lowering of the exfoliation temperature was observed for compensated and arsenic doped Si layers. The hydrogen implantation converted silicon wafer surface from p-type to n-type. The as-transferred Si layer was also found to be ntype after annealing at 200–450°C. The p-type conductivity was restored upon annealing at around 600°C. We believe that this conductivity conversion is due to the combined effect of ion-enhanced thermal donors and the presence of H-related shallow donors in the implanted layer. The p-type conductivity is restored at higher temperatures following the dissociation of the thermal donors and the out-diffusion of hydrogen. We also report that a good quality silicon on glass layer can be obtained by the bonding and ion-cutting processes.