At present, the key to the development of LED chip technology lies in the substrate material and wafer growth technology. In addition to traditional sapphire, silicon (Si), silicon carbide (SiC) substrate materials, zinc oxide (ZnO) and gallium nitride (GaN) are also the focus of current LED chip research. At present, most of the commercially available sapphire or silicon carbide substrates are used to epitaxially grow wide-bandgap semiconductor gallium nitride. Both materials are very expensive and are monopolized by foreign large companies, and the price of silicon substrates is higher than that of sapphire and carbonization. Silicon substrates are much cheaper, making larger substrates and increasing the utilization of MOCVD, thereby increasing tube crystal yield. Therefore, in order to break through international patent barriers, Chinese research institutions and LED companies began research on silicon substrate materials. However, the problem is that the high-quality combination of silicon and gallium nitride is a technical difficulty of the LED chip. The technical problems of high defect density and crack caused by the large mismatch between the lattice constant and the thermal expansion coefficient of the two have long hindered the chip field. development of. Undoubtedly, from the perspective of the substrate, the mainstream substrate is still sapphire and silicon carbide, but silicon has become the future development trend of the chip field. For China, where the price war is relatively serious, the silicon substrate has more cost and price advantages: the silicon substrate is a conductive substrate, which not only reduces the tube crystal area, but also eliminates the dry etching step of the gallium nitride epitaxial layer. In addition, silicon has a lower hardness than sapphire and silicon carbide, and it can also save some costs in processing. At present, the LED industry is mostly based on 2 or 4 inch sapphire substrates. If silicon-based gallium nitride technology can be used, at least 75 raw material costs can be saved. According to estimates by Japan's Sanken Electric Co., the manufacturing cost of making large-size blue-GaN GaN LEDs using silicon substrates will be lower than that of sapphire substrates and silicon carbide substrates. 90. International OSRAM, BRIDGELUX, Japan Sam Leading companies such as SAMCOINC have made breakthroughs in the research of large-size silicon-based GaN-based LEDs. Philips, South Korea's Samsung, LG, Japan's Toshiba and other international LED giants have also set up a GaN-based silicon substrate. LED research boom. Among them, in 2011, Puri developed high-efficiency GaN-based LEDs on 8-inch silicon substrates, achieving luminous efficiency comparable to that of top-level LED devices on sapphire and silicon carbide substrates of 160 lm/W. In 2012, Osram successfully produced a 6-inch silicon substrate with gallium nitride-based LEDs. In contrast, China's breakthrough in LED chip technology is mainly to increase production capacity and large-size sapphire crystal growth technology, in addition to Jingneng Optoelectronics in 2011. In addition to mass production of GaN-based high-power LED chips on 2-inch silicon substrates, Chinese chip companies have made no breakthrough in the research of GaN-based LEDs on silicon substrates. At present, China's LED chip companies are still focusing on production capacity and sapphire substrates. Materials and wafer growth technologies, such as Sanan Optoelectronics, Dehao Runda, Tongfang, and other Chinese chip giants have also made breakthroughs in production capacity.