GaN has no native substrate; procedures to grow bulk GaN are costly and difficult to realize. This forces developers to grow epitaxial GaN onto non-native substrates. Defects are created from lattice mismatches, variations between the atomic spacing of the materials, that directly degrade device performance.

Currently, the substrate materials being used for the growth of nitride based devices are sapphire, SiC, silicon, and ZnO.

Sapphire substrates are relatively inexpensive, but have severe limitations for growing high quality devices. Silicon carbide is better suited as a substrate material, but is very costly and produces a relatively large number of defects.Silicon substrates require complex lateral overgrowth epitaxy mechanisms which can be expensive and hard to achieve.