Faced with the rapid development of new technologies and the continuous breakthrough of old technologies, today, which three different substrate technology routes, SiC, sapphire and silicon, are more advantageous in terms of cost and performance? If more and more companies start Will mass production of silicon substrates form an impact on the two technical routes of SiC and sapphire? What are the different technical routes and the progress of relevant research institutions at home and abroad? Which substrate technology route will be more optimistic in the future? Take you to know what you think about the future development of these three different substrate technologies.

"Competition" silicon substrate

Although there are many substrate materials that can be used for GaN-based LEDs, the current mainstream substrates for industrialization are only two types of sapphire and SiC. Because these two technical routes are subject to bottlenecks such as patents, technical barriers and high costs, exploring the substrate technology route with higher cost performance has become the pursuit of many manufacturers. As a substrate material, silicon has advantages of low cost, large size, high quality, and electrical conductivity compared with sapphire and SiC. The development of GaN-based materials and devices on silicon substrates will further promote GaN-based devices and traditional silicon linings. The integration of the bottom device process is considered to be a promising GaN substrate material. At present, more and more LED manufacturers in the world have joined the ranks of research on silicon substrate technology.

According to the reporter's investigation, the quality and performance data of silicon substrate LED chips developed by many companies have been comparable to sapphire substrate chips. For example, when the color temperature of Puri photoelectric 8-inch silicon substrate chip is 4700K, the light efficiency has reached 160lm/W; when the color temperature is 3000K, the light efficiency has reached 125lm/W, and the color rendering index can reach 80. Blu-ray UX in the OSRAM standard Golden Dragon Plus LED package: The 3 chip has a brightness of 634mW at 3.15V. If combined with the traditional phosphor conversion in the standard package, these white LED prototypes will have a brightness of 140lm at 350mA and the color temperature will be A light efficiency of 127 lm/W will be achieved at 4500K. Crystal energy photoelectric 2 inch silicon substrate mass production chip, color temperature is 5000K, the general light efficiency at 350mA exceeds 110lm / W, 6-inch silicon substrate chip research and development has made significant progress, performance and 2 inch film is equivalent, is currently preparing for 6 inch Mass production process equipment. In addition, Philips and Samsung are also conducting research on silicon substrates, and Samsung has been aiming at the direct entry of 8-inch large size from the beginning... It can be predicted that the semiconductor lighting core technology triggered by silicon substrate Competition is on the rise globally.

It is more difficult to grow GaN on a silicon substrate than sapphire and SiC, where the thermal mismatch and lattice mismatch are greater. The person in charge of Purui Optoelectronics said that the new scheme adopted has broken through the technical barriers that the GaN upper and lower layers cannot be combined on the silicon substrate, but the technical details of the new schemes currently used are not disclosed. The person in charge of Purui Optoelectronics said that in the future, it will choose the foundry model, and cooperate with experienced world-class semiconductor companies to mass produce silicon substrates and improve product yield. It is expected to be put into production in early 2013. OSRAM, which has made good progress in the development of silicon substrates, announced in early 2012 that its developers have successfully produced high-performance blue-and-white LED prototypes with GaN light-emitting layers grown on a 6-inch-diameter silicon substrate. . Osram Asia Pacific Marketing Director Zhong Jiecong said: "At present, the laboratory level has been able to obtain the same quality as the sapphire substrate. The new LED chip has entered the pilot stage and will be tested under actual conditions. The first batch of silicon substrate LED chips are expected to be Put on the market within two years."

At the same time that foreign manufacturers have rapidly improved the research and development level of silicon substrates, the world's first unit crystal energy photoelectricizer that realizes the commercialization of GaN-based LED high-power chips on silicon substrates has already started the industry of silicon substrate LED chips as early as 2006. Attempts have been made to introduce a variety of silicon substrate LED chips, with an overall yield of about 80%. According to the reporter's understanding, the main technical support unit of Jingneng Optoelectronics, the national silicon-based LED engineering technology research center has also successfully developed the second-generation silicon substrate LED, which has significantly improved light efficiency, pass rate and reliability, while manufacturing process is greatly improved. Simplified, the cost is significantly reduced.