Recent progress of GaN growth on maskless chemical-etched grooved sapphire substrate

A new GaN lateral epitaxial overgrowth (LEO) technique using a chemical-etched grooved sapphire substrate is demonstrated here. The substrate fabrication, selective growth mechanism and dislocation reduction mechanism are discussed. By applying this technique, improvement in the quality of wing tilt free GaN LEO films and enhancement of GaN LEDs can be achieved.