Recrystallization prospects for freestanding low-temperature GaN grown using ZnO buffer layers

Remote plasma enhanced-laser-induced chemical vapor deposition was used to grow gallium nitride films on zinc oxide buffer layers deposited by atomic layer epitaxy on soda lime glass. Freestanding layers of gallium nitride were processed by etching away the substrate and ZnO buffer layer. The n-type carrier mobility for the GaN on ZnO/soda lime glass was found to be similar to the highest values achieved on pure silica, and was accompanied by high carrier concentration. As-grown polycrystalline materials were recrystallized at low temperature (below the 570 °C gallium nitride growth temperature). This recrystallization process greatly improved the film structure with a self-assembled multilayer structure evident in the oxygen-rich surface layer of the films that had undergone the process.