Superlattice GaN-on-silicon heterostructures with low trapping in 1200 V

The aim of this work is to investigate the role of the epitaxial structure on the low trapping effects of GaN-on-silicon heterostructures use for power application. Structures with and without superlattices (SL) are analysed. In particular, it is shown that the insertion of SL into the buffer layers allows pushing the vertical breakdown voltage above 1200 V without generating additional trapping effects as compared to a more standard GaN-based epi-structure using similar total buffer thickness. A low trapping effect down to-1.2 kV has been observed with substrate ramp measurements. Indeed, we demonstrated that a structure with SL shows a reduction in the trapping effects with high vertical breakdown.