Japan's Shimei semiconductor development of silicon-based 10mW Blu ray LED

Venture Kyoto Shimei semiconductor, on silicon substrate is developed on GaN light emitting diode (LED) chip (the Web site). Among them, the output power of blue LED for maximum 10mW, with almost the same power universal blue LED chip, "compared with the blue LED chip fabricated on sapphire substrate, the manufacturing cost less than half" (the company). According to reports, the reason why to reduce manufacturing costs, because compared with the sapphire substrate, the price of the silicon substrate is only about 1/10, in addition to the bottom of the silicon substrate than sapphire soft, easier to process. The luminous wavelength of the new product is 450nm. Chip size 0.3mm square. 20mA drive when the luminosity of 1.5 ~ 2cd. In addition to the blue LED, purple Ming semiconductor is also made on the silicon substrate green LED.

In general, when the GaN film is formed on the silicon substrate, the thermal expansion rate and lattice constant of GaN and silicon are different, so it is easy to produce cracks and other defects. At the same time, the defects were produced by stacking layers of AlInGaN and AlInGaN as the buffer layer on the silicon substrate. Use the same technique, Japan Sanken electric (Sanken Electric) and the Nagoya Industrial University is to develop production in silicon on the base class GaN LED. Sanken electric through the silicon plate stacked multilayer AlN and GaN interaction as a buffer layer.

Because the silicon absorbs light more easily than sapphire, the reflection structure is set on the blue LED buffer layer. Compared with sapphire, silicon has the advantages of high thermal conductivity, and the heat dissipation characteristics of GaN class LED fabricated on the silicon substrate can be improved. Different from the insulating sapphire, silicon can be conductive, so it also has the advantage that the N electrode can be installed on the bottom of the LED chip. Typically, the LED made of sapphire substrate, due to the sapphire as an insulator, it must be part of the upper part of the LED to install the n electrode. The use of silicon substrate, you can cancel the cutting process, it is expected that the yield will be improved. In addition, according to the introduction, due to the hardness of silicon than sapphire and SiC low, it is easy to cut, so it is easy to improve the yield.

Shimei semiconductor plans to supply samples from April 2007, is currently preparing for the preparation of 3 million chips per month. In addition to the naked chip (Bare Chip) mode of sale, Shimei semiconductor also consider wafer supply