In order to meet the growing market demand, Showa Denko Group (SDK) has developed a new process for manufacturing gallium nitride (GaN)-based and other nitride-based high-quality composite semiconductors, mainly for blue and white light-emitting diodes (LEDs). .
This new process is called "Mixed PPD Process!" and is a combination of the conventional Metal Organic Chemical Vapor Deposition (MOCVD) process and the Showa Group's unique Plasma Assisted Physical Deposition (PPD) process. The PPD process is used to form a nitride-based semiconductor crystal.
With this new process, it is possible to produce high-quality four-inch epitaxial wafers that cannot be produced by conventional metal organic chemical vapor deposition (MOCVD) processes. Using the hybrid PPD process, Showa (SDK) has also successfully developed the blue LED with the highest brightness on the market. Showa (SDK) will launch this blue light-emitting diode this year. The Changsha Electric Group (SDK) has decided to build a production line in Chiba, Japan, using this new technology to produce four-inch epitaxial wafers. Due to the large number of wafers produced by the new technology and the new production line, the production capacity of the blue light-emitting diode of Showa Denko Group (SDK) will be greatly increased. The current monthly output is 30 million, and will increase by the end of this year. To 100 million per month.
Introduction to the new process of hybrid PPD At present, the illumination efficiency of gallium nitride-based blue or white light-emitting diodes (typical nitride-based composite semiconductors) has surpassed that of other light sources (such as incandescent lamps, fluorescent lamps), but the mass production of high-quality epitaxial wafers is new. Technology is still very much needed.
The Showa Denko Group's (SDK) hybrid PPD process ensures significant efficiency gains and produces a four-inch epitaxial wafer with better crystal quality.
At the same time, the new mixed PPD process of Showa Denko Group (SDK) can produce multi-layer high-quality crystals based on the epitaxial growth process accumulated over many years; and the production efficiency is more than the traditional metal organic chemical vapor deposition (MOCVD) process. high. The Showa Denko Group's (SDK) hybrid PPD process technology has applied for more than 30 patents.
According to the X-ray rocking curve (XRC) method, the sapphire substrate produced by the PPD process has a single crystal nitride layer formed thereon as compared with a similar product produced by a metal organic chemical vapor deposition (MOCVD) process. The crystal quality showed a significant improvement.
Explanation of terms:
Nitride-based composite semiconductors are based on the general term of (Alx, Gay, In1-xy)N composite semiconductors, and are mainly used to produce ultraviolet and green light-emitting diodes and blue laser diodes (LD). As a new type of electronic device material, these products are attracting people's attention.
Gallium Nitride (GaN)-based light-emitting diodes According to different compositions, gallium nitride-based light-emitting diodes emit various light from ultraviolet to green light. If an ultraviolet or blue light-emitting diode is combined with a fluorescent substance, it is possible to produce a light-emitting diode having a wide wavelength range. (A fluorescent substance is a kind of luminescent substance that converts some of the absorbed light into different wavelengths of light and emits it.)
Epitaxial growth A technique for forming a semiconductor layer in which a crystal layer formed on a substrate has the same crystal orientation as the substrate.
Source: Electronic Engineering 