Compared with Si, GaAs and InP, the third generation semiconductor materials have superior properties such as high breakdown electric field strength, high thermal conductivity, high electron saturation rate, high drift rate, and high radiation resistance. These advantages are expected to significantly reduce the loss and volume/weight of devices. Therefore, the third generation semiconductor materials have incomparable advantages and broad application prospects in the fields of high power, high frequency, high voltage, high temperature, and high optical efficiency.

China has developed hydride vapor phase epitaxy (HVPE) technology with independent intellectual property rights, achieved mass production of 2-inch self-supporting GaN substrate and 4-inch small batch shipment, achieved research and development of 6-inch GaN single crystal substrate, and the crystal quality has reached the international advanced level. In terms of GaN epitaxy, it is mainly divided into GaN on silicon, GaN on Si, GaN on SiC and GaN on GaN according to different substrates. GaN on appliance is mainly used in the LED market, with the mainstream size of 4 inches; GaN on Si is mainly used in the power electronics and optoelectronics markets, realizing the mass production of 6-8 inch GaN epitaxial wafers on Si, overcoming the key technical problems such as cracking and warping of GaN epitaxial materials on large size Si substrates, and some technologies are at the international advanced level; GaN on SiC is mainly used in microwave and RF markets. China has successfully grown high-quality GaN HEMT epitaxial wafers on 4-inch SiC substrates; The main application market of GaN on GaN is blue/green laser, and China has not yet achieved industrialization.

The 4-inch free-standing GaN wafer produced by Eta Research has filled the gap of the third generation GaN semiconductor materials in China. The wafer thickness is 800 microns, the warp is less than 0.1 mm, and the lattice curvature radius is 20 meters. All technical indicators are at the leading level in the world.