Analysis on the dislocation of GaN on different substrate

Though there are still disputes on whether the threading dislocation density (TDD), to produce high quality Gallium Nitride ( GaN ) with low TDD is needed. In this passage, we would first show the impact of dislocation and review the latest methods to reduce dislocation on Si, GaN, and sapphire. The Si substrating with serpentine channels could produce GaN by using Si substrate with low density dislocations. The method that use the markless-3D provides a new way to reduce the dislocation from big off-angle. The multiple-step growth technique controls the conditions of crystallization and use two steps of crystallizing to grow with both low dislocation density and 2D growth shape. The last method is to use the Na-flux method to exclude cracks with sapphire in crystal.