Electrical Efficiency

Vertical transistors based on bulk gallium nitride (GaN) have emerged as promising candidates for future high efficiency, high power applications. However, they have been plagued by poor electrical performance attributed to the existing selective doping processes. Sandia National Laboratories will develop patterned epitaxial regrowth of GaN as a selective area doping processes to fabricate diodes with electronic performance equivalent to as-grown state-of-the-art GaN diodes.

Advanced doping methods are required to realize the potential of gallium nitride (GaN)-based devices for future high efficiency, high power applications. Ion implantation is a doping process used in other semiconductor materials such as Si and GaAs but has been difficult to use in GaN due to the limited ability to perform a damage recovery anneal in GaN. JR2J will develop an innovative laser spike annealing technique to activate implanted dopants in GaN.

Arizona State University (ASU) proposes a comprehensive project to advance fundamental knowledge in the selective area doping of GaN using selective regrowth of gallium nitride (GaN) materials. This will lead to the development of high-performance GaN vertical power transistors. The ASU team aims to develop a better mechanistic understanding of these fundamental materials issues, by focusing on three broad areas.

Adroit Materials will develop a gallium nitride (GaN) selective area doping process to enable high-performance, reliable GaN-based, high-power switches which are promising candidates for future high efficiency, high power electronic applications.. Specifically, doping capabilities that allow for the creation of localized doped regions must be developed for GaN in order to reach its full potential as a power electronics semiconductor.

Yale University will conduct a comprehensive investigation to overcome the barriers in selective area doping of gallium nitride (GaN) through an epitaxial regrowth process for high-performance, reliable GaN vertical transistors. Transistors based on GaN have emerged as promising candidates for future high efficiency, high power applications, but they have been plagued by poor electrical performance attributed to the existing selective doping processes.

Livermore National Laboratory (LLNL) will advance GaN device processing knowledge to enable production of GaN devices with higher speed and power at a lower cost. Using a selective area p-type doping process to move the device architecture from a lateral to a vertical configuration makes the lower cost possible. LLNL has previously demonstrated solid-state diffusion of magnesium (Mg) into GaN at temperatures under 1000ºC through a Gallidation Assisted Impurity Diffusion (GAID) process.

Qromis Inc. will develop an improved selective area doping fabrication method for GaN, ultimately enabling a broader range of higher-performing, manufacturable, and scalable GaN power devices. The team seeks to improve the process using magnesium (Mg) diffusion, in which atoms move from an area of high concentration to a lower one at high temperatures. In particular, Qromis seeks to understand what controls the Mg diffusion rate in GaN to better leverage the phenomenon for the production of high-performance devices.

The University of California-Santa Barbara will develop a low power, low-cost solution to overcome power and bandwidth scaling limitations facing hyperscale data centers and exponential growth in global data traffic. The FRESCO transceiver leverages advances in fundamental laser physics and photonic integration to enable terabit, coherent optical data transmission inside data centers through chip-scale spectrally pure and ultra-stable wavelength division multiplexed laser light sources .

Hewlett Packard Labs will develop a low energy consumption, ultra-efficient, high-speed technology to transmit data as light in high-performance computing systems and data centers. The team will combine recent breakthroughs in low-cost laser manufacturing and ultra-efficient photonic tuning technology with their established platform. It will demonstrate a fully integrated optical transceiver capable of sending data faster than 1,000 gigabytes per second over 40 simultaneous channels, even in rigorous practical operating conditions with widely varying temperatures.

The Ohio State University will develop GaN semiconductor materials suitable for high voltage (15-20 kV) power control and conversion. The team will develop a unique photon-assisted metal organic chemical vapor deposition (PA-MOCVD) method to grow thick GaN films with low background impurity contamination, necessary to allow high-voltage operation with high efficiency. The thick GaN layers will be deposited by PA-MOCVD on high-quality bulk GaN base materials with reduced defects, critical to the growth of high-quality GaN films.