New technology can replace sapphire substrate significantly reduce the cost of LED production

According to physicist organizational network reported recently, a new manufacturing technology is expected to significantly reduce the light emitting diode (LED) of the cost of production, to further promote the process of popularization.

The study conducted by researchers at SIEMENS subsidiary OSRAM Opto Semiconductors research successfully on silicon substrate to produce Gan LED chip, instead of the more expensive sapphire substrate used commonly at present.

Silicon is a kind of standard semiconductor material, which has the advantages of large size, low cost, easy processing, good conductivity and so on as LED substrate. However, the technical difficulty lies in the different coefficient of thermal expansion of silicon and gallium nitride, which is easy to produce stress in the manufacturing process, which leads to the uneven thickness of the film or the rupture, so it has not been widely used in the LED industry. Through a special process, the new technology not only avoids the previous cracking phenomenon, but also makes the stability and brightness of the new LED is the same as the traditional sapphire substrate LED, very suitable for high-power solid-state lighting.

LED is a highly efficient energy-saving lighting program, is considered to be the most promising to replace the traditional light source. However, so far, the production cost of LED has been higher than other more mature lighting products, so it has not been widely used in daily life. Through the use of new technologies, LED production will be expected to use a larger area of silicon, which will be a major upgrade of LED production efficiency.

With this technology, OSRAM has successfully produced a diameter of 150 mm (6 inches) of high-performance LED wafers. Researchers have begun to adjust the production process to manufacture 200 mm (8 inch) wafers. This will further increase the number of chips per substrate and reduce production costs. It is understood that most of the LED industry is based on 50 mm (2 inches) or 100 mm (4 inches) sapphire substrate, such as silicon nitride technology can be used to save at least 75% of the cost of raw materials.

At present, this kind of new LED based on thin film is still in the trial stage of the sample, and then it will be tested in the real environment. Preliminary experiments show that the technology made of blue and white silicon based LED can achieve similar performance with the current market sapphire substrate products. The first commercial LED products using the technology are expected to be available two years later.