Silicon substrate, among the mainstream when to wait?

Substrate as the core technology of semiconductor lighting industry, is the cornerstone of the development of industry, the substrate material directly determines the route LED chip manufacturing. The day before, Bridgelux announced 8 inch silicon substrate will be mass production next year news aroused special attention. Subsequently, Cree also announced that its white power type LED light efficiency once again refresh the industry record, reaching 254lm/W. One side is the silicon substrate of this new technology research breakthrough when the news broke, one side is the rapid increase of SiC chip light effect, but also because of low price of sapphire substrate to the bottom and show the competitiveness of overcapacity. In the face of the rapid development of new technologies and the continuous breakthrough of the old technology, and now, SiC, sapphire, silicon, these three different substrate technical route, which is more advantageous in terms of cost and performance? If more and more companies began to produce silicon substrate, whether it will SiC and sapphire two technical routes to form an impact? Different technical routes, domestic and foreign research institutions and progress? What kind of substrate technology will be more promising in the future? This reporter takes you to understand the future development of these three different substrate technology.

Silicon substrate

Although the substrate material can be used for GaN based LED more, but there are only two kinds of substrates and SiC. Because of these two technical routes by patents, technical barriers and high cost of bottleneck constraints, to explore a more cost-effective substrate technology route has become the pursuit of many manufacturers. Silicon as a substrate material, compared with sapphire and SiC, has the advantages of low cost, large size, high quality, conductive advantages, and the development of silicon substrate GaN based materials and devices will further promote the integration of GaN based devices with traditional silicon device technology, is considered to be a very promising GaN substrate material. At present, more and more LED companies in the world have joined in the research on the technology of silicon substrate.

According to the reporter learned that the quality and performance of LED chip on the silicon substrate before the data has been a lot of research and development of chip and the sapphire substrate is beautiful. For example, when the 8 inch silicon substrate color temperature is 4700K, the light efficiency has reached 160lm/W, the color temperature is 3000K, the light effect has reached 125lm/W, the color rendering index can reach up to 80. Blue UX:3 chip OSRAM Golden standard Dragon Plus LED package in 3.15V brightness can reach 634mW, if combined with traditional fluorescent powder standard package in the conversion, these white LED prototype at 350mA current brightness will reach 140lm, the color temperature is 4500K to achieve the optical efficiency of 127lm/W. Latticepower 2 inch silicon chip production, the color temperature is 5000K, 350mA under the common light efficiency more than 110lm/W, 6 inch silicon chip development made significant progress, performance and 2 inch tablet, currently preparing for the 6 inch production process equipment. In addition, PHILPS, Samsung are also studied in terms of the silicon substrate, and Samsung is the beginning of the 8 inches of the large size of the direct start...... It can be predicted that the competition for semiconductor lighting core technology triggered by the silicon substrate is set off worldwide.

Compared with sapphire and SiC, it is more difficult to grow GaN on silicon substrate, and the thermal mismatch and lattice mismatch are larger. Puri said the person in charge, the new program has broken through the silicon substrate GaN on the upper and lower levels of technical barriers, but the current technical details of the new program is still not disclosed. Puri said the person in charge of the future will choose the foundry model, with experienced world-class semiconductor companies to cooperate in the production of silicon substrate, improve product yield, is expected to be put into operation in early 2013. Research on silicon substrate has also made good progress in early 2012, OSRAM announced that the researchers succeeded in producing high performance blue light LED prototype, the silicon substrate GaN light-emitting layer growth to 6 inches in diameter on the bottom. OSRAM Asia Marketing Director Zhong Jiecong said: "the current laboratory level has been able to get the same quality of sapphire substrate, the new LED chip has entered the pilot phase, will be tested on the actual conditions, the first silicon substrate LED chip is expected to hit the market within two years. "

In the foreign manufacturers to quickly upgrade the level of R & D silicon substrate at the same time, the world's first implementation of GaN based LED unit crystal silicon substrate high-power chip commercial power, started as early as 2006 for silicon substrate LED chip industrialization attempt, has launched a variety of specifications of the silicon substrate of LED chip, the overall yield is about 80%. According to the reporter, the main technology of photoelectric crystal can support units of the National Engineering Research Center for silicon-based LED has successfully developed the second generation silicon substrate LED, light efficiency, yield and reliability has significantly improved, and the manufacturing process is greatly simplified, lower cost.

"More and more companies are involved in the research on silicon substrate and achieved rapid progress, it also shows that the technical route of the silicon substrate LED is gradually becoming one of the important technology of LED lighting, thus, the silicon substrate LED will occupy a higher market share. At the same time, domestic silicon substrate LED is no longer lonely, and its recognition and market acceptance, not because of a single source of supply and affect the user to promote the use of confidence. Jiang Fengyi, professor at Nanchang University, said: we are now the silicon substrate LED growth of MOCVD equipment manufacturing and epitaxial process combined, has made gratifying progress. Rapid progress over the past year, more determined to take the road of independent innovation confidence and determination. At present, the project has been supported by the Ministry of science and technology, Ministry of industry, development and Reform Commission and Jiangxi, Nanchang. Believe that insist on