Ion-Implant Isolated Vertical GaN p-n Diodes Fabricated with Epitaxial Lift-Off From GaN Substrates

摘要

Ion-implant isolated vertical GaN p-n junction diodes fabricated with epitaxiallift-off (ELO) from GaN substrates are demonstrated. For the ELO process, aband-gap selective photoelectrochemical (PEC) wet etch with a pseudomorphicInGaN release layer is utilized. Compared with devices isolated usingmesa etching, the ion-implant isolated devices exhibit more ideal forwardcurrent–voltage characteristics and lower leakage currents. Devices are alsocompared with and without ELO processing. Devices measured after ELOprocessing and mounting to metallized carrier substrates show similarelectrical performance to GaN-on-GaN control samples without ELO processing.No indication of material quality degradation is found on the ELOdevices. The ELO devices exhibit turn-on voltages of 3.15 V (at a currentdensity of 100 A cm~(-2)), with specific on resistance (R_(on)) of 0.52mΩcm~2 at4.8 V and breakdown voltage (V_(br)) approximately of 750 V.