ABSTRACT
Gallium nitride-based semiconductors continue to attract much attention for the applications in light-emitting diodes, laser diode, and transistors. The high exciton binding and oscillator strength in GaN and its related heterostructures make microcavity structures very promising for room-temperature operation of devices such as edge-emitting lasers, polariton lasers, and optical amplifiers. Heteroepitaxy is an attractive approach to realize the microcavity, but is restricted by the limited materials quality and the narrow high-reflectivity stopbands. A heterogeneous approach is much more attractive, in which the lift-off high-quality GaN thin film is bonded to a metallic or dielectric mirror. Research on lift-off of GaN thin film has been conducted over the last two decades. This chapter reviews the various methods to lift-off GaN film and its related progress in the field.
