Next-Generation, Power-Electronics Materials for Naval Aviation Applications

This STTR project develops an innovative seed fabrication technology to address the fundamental size-quality limitation of gallium nitride (GaN) substratesthe indispensable key component for GaN-based vertical high-power devices. Currently, there is no viable GaN technology to realize large-area and low-defect substrates simultaneously. The technology producing 6" and larger GaN wafers results in defect densities as high as 1e9 cm-2 whereas the technology achieving defect densities of 1e5 cm-2 or less can only provide 2" wafers. To solve this dilemma, SixPoint Materials and UC Santa Barbara will explore both a tiling method (lateral crystal fusing) and a layer transfer method, to develop high-quality 4" GaN engineered seed crystals suitable for SixPoint's proprietary near equilibrium ammonothermal (NEAT) method, which can achieve dislocation density of 2 x 1e5 cm-2 or less. The Phase I effort will focus on proof of concept with 10 x 20 mm seeds. During the Phase I option period, 2" engineered seeds will be achieved. By the end of Phase II, this project will achieve 4" GaN substrates with defect densities lower than 1e5 cm-2 and accelerate the wide adoption of vertical GaN power devices in both military and civil applications.