Properties of free-standing GaN prepared by HVPE using AlN/Si substrate

A hydride vapor phase epitaxy (HVPE) method was employed to grow a thick-film GaN on AlN/Si substrates, and the subsequent chemical removal of the Si substrate resulted in freestanding GaN substrates without cracks, having a current maximum size of 10x10 mm(2) and a thickness of 350 mu m. The freestanding and crack-free GaN single crystalline substrate is useable for homoepitaxial growth of GaN, and the HVPE method is a promising approach for the preparation of large area, crack-free GaN substrates.