Epitaxial lift-off using band gap selective photoelectrochemical etching is demonstrated for vertical GaN power devices. The use of a pseudomorphic InGaN release layer enables low dislocation-density material to be achieved on bulk GaN substrates; this enables high breakdown voltages and low reverse leakage currents to be achieved. Demonstrations of bipolar GaN pn junction diodes show that device electrical performance is not compromised by the lift-off processing. Thermal performance can also be improved by directly bonding the lifted off devices to high-thermal conductivity carriers. Epitaxial liftoff has the potential to improve size, cost, weight, and thermal performance of power electronics, as well as enabling heterogeneous integration.
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