This Small Business Innovation Research Phase I project advances a novel method to manufacture nitride-based light emitting diodes (LEDs). Currently, LEDs are expensive due to the fact that they are produced on sapphire substrates using thermal metal organic chemical vapor deposition (MOCVD). In this project, we will develop a new low-temperature buffer layer technology to enable gallium nitride film growth on silicon substrates. The current buffer layers for gallium nitride growth on silicon by MOCVD require high-temperature processing. This leads to high tensile stress in the film, resulting in poor crystal quality and wafer bowing, which lead to yield loss, and in some cases even cracking of the wafer. The low-temperature buffer layer growth is challenging, as the films tend to grow in a three-dimensional columnar mode at lower temperatures. To overcome this technical risk, a novel buffer will be developed that can also be scaled to large area processing.
The broader impact/commercial potential of this project will accelerate the mass-scale adoption of LEDs by reducing their manufacturing cost. LEDs have tremendous potential to make a positive societal impact due to their energy efficiency and the associated environmental benefits. However, LEDs currently cost 5 to 10 times as much as compact fluorescent lighting, preventing large-scale adoption. By allowing the use of silicon substrates and increasing growth rates, our new manufacturing process has the potential to reduce the LED manufacturing cost by up to 7.5 times for volume production. Moreover, the buffer technology to be developed in this project is also applicable to a wide range of other optoelectronic applications. Therefore, the successful completion of this project would not only have a significant societal impact by accelerating LED adoption, but also have positive economic impact by creating US green jobs and maintaining US technology leadership in a wide range of optoelectronic applications.
