Optimization of H+ implantation parameters for exfoliation of 4H-SiC Films

Ion-beam assisted exfoliation of thin single crystalline layers of 4H-SiC can lead to heterogeneous integration of SiC devices with silicon CMOS circuits, and to reduced cost of SiC power devices. Practical device structures require H+ ion implantation and wafer bonding in order to achieve transfer of crystalline layers to new handle substrates. However, for initial optimization of the exfoliation step it is sufficient to monitor surface blistering as a function of the of ion implantation parameters and the subsequent thermal annealing conditions. In this study we show that for 1 μm thick 4H-SiC exfoliated films, there is an optimum implantation dose of about 6×1016 cm-2 at 180 keV. The layer transfer is more difficult for higher as well as lower doses. Material doping and small changes in crystalline orientation do not have much impact on the exfoliation.