China LED chip technology development currently

At present, the development of key technology is the LED chip and wafer substrate material growth techniques. In addition to the traditional sapphire, silicon (Si), and silicon carbide (SiC),  the substrate material, zinc oxide (ZnO) and gallium nitride (GaN), etc. are also the focus of the current LED chip research. Currently, the market adopts most of sapphire or silicon carbide substrates for epitaxial growth of a wide bandgap semiconductor gallium nitride. These two materials prices are very expensive, and are monopolized by large foreign companies. While the price of silicon carbide and sapphire substrate ratio a silicon substrate is much cheaper, and they can produce a larger substrate and improve the utilization of MOCVD to increasing die yield. Therefore, in order to break through the barriers of international patents, research institutes and China LED companies start from working on the silicon substrate material.

But the problem is that high-quality combination of silicon and gallium nitride LED chips are technical difficulties, defects huge mismatch between the lattice constants and thermal expansion coefficient and high density caused by cracks and other technical problems have long hindered the chips development of.

No doubt, from the point of view of the substrate, the substrate is still the mainstream sapphire and silicon carbide, the silicon has become the future development trend of chips. For the price war in China is relatively serious, the silicon substrate is more cost and price advantage: a silicon substrate is a conductive substrate, not only can reduce the die area, can also be eliminated on the gallium nitride epitaxial layer dry etching step , combined with the hardness lower than that of silicon carbide and sapphire, the processing can also save some costs.

Most of the current LED industry produces mainly on 2 inches or 4-inch sapphire substrate based, such as silicon-based GaN technology can be employed,which can save at least 75% of the cost of raw materials. According to the estimates of Japan Sanken Electric Company that the cost of the production of large-size silicon substrate using gallium nitride blue LED is 90% lower  than sapphire and silicon carbide substrates .