Silicon substrate LED lighting yet found physical bottlenecks

In accordance with the substrate used in the preparation of LED upstream materials, there are three technical routes to realize the industrialization, namely, sapphire substrate semiconductor lighting, silicon carbide substrate semiconductor lighting and silicon substrate semiconductor lighting. One of the core patents before the two technical route is mainly in the hands of TOYOTA, CREE, Nichia, synthetic OSRAM, PHILPS, the United States and Europe several giant companies, while the silicon substrate GaN based LED patented technology for our country, is an important technical route to achieve a breakthrough in international patent blockade of LED industry.

Both blue and green LED red or yellow light LED, either gallium nitrogen system or al-ga-in-p system, whether it is sapphire, silicon carbide, silicon substrate or GaAs substrate, high brightness LED chip manufacturing technology, were developed to peel substrate preparation LED thin film line. The reason is: one is the epitaxial film transferred to the new board, is conducive to heat, reduce the junction temperature, improve the luminous efficiency and prolong service life of device; two is through the production of P reflector and N surface roughening, significantly improve the light efficiency; three is conducive to the improvement of the chip working current density. Compared with other substrates, silicon substrate epitaxial semiconductor lighting materials, very suitable for walking film stripping substrate transfer technology, and silicon material than silicon carbide and sapphire are much cheaper, but also easy to get the substrate size, it will significantly reduce the cost of the growth of epitaxial material.

Of course, there is a mismatch between GaN and Si substrate thermal mismatch, lattice mismatch and other problems, it is easy to crack phenomenon, it is a serious challenge to grow high quality GaN based LED on silicon substrate. In this respect in the world that can photoelectric crystal silicon substrate, LED lighting has not yet found the bottleneck of the physical, crack problems can be solved by graph and planar substrate, the dislocation density can reach 3-10 * 108cm2, and the performance is stable under high current density.

GaN/Si LED has entered the market, promising. However, the current high price of gold with bonding, to be looking for alternatives. In fact, there are a lot of SSL science and technology issues are not resolved, so whether it is the device or epitaxial chip, are opportunities and challenges coexist. SSL and technological progress too fast, it also brought difficulties to the investors, the investment need to be cautious.