Kyma Technologies Inc of Raleigh, NC, USA (which provides crystalline nitride materials, crystal growth and fabrication equipment, and power switching electronics) and Quora Technology Inc have announced a strategic partnership in the development and commercialization of GaN substrate materials.
Kyma is a developer of wide-bandgap semiconductor (WBGS) materials solutions, including gallium nitride (GaN), aluminium nitride (AlN), gallium oxide (Ga2O3) and diamond. GaN materials products include free-standing GaN substrates and GaN templates.
Established in March 2015 in California's Silicon Valley, Quora is a privately held fabless technology startup focusing on energy-efficient and high-performance WBGS materials and device solutions.
Quora is commercializing its QST substrate technology, which is fully diameter-scalable (6", 8", 12" and beyond) and engineered at a fundamental level to alleviate stress from epitaxial layers, allowing the deposition of tens of microns of high-quality and low-dislocation-density GaN on 6" or larger diameters. Quora reckons that, with validated performance results in LED, power and RF applications by major GaN device manufacturers, its QST substrate solution is poised for adoption in the WBGS industry.
Kyma and Quora have teamed to demonstrate that Kyma's high-growth-rate GaN processes can be used to realize a low-defect GaN-on-QST template that leverages the QST properties and provides a high-quality epi-ready surface for GaN epitaxial growth and device fabrication.
Kyma has confirmed that they can produce uncracked, low-defect-density (<108cm-2) 6"-diameter GaN-on-QST templates that have up to 40% narrower x-ray diffraction (XRD) linewidths, smoother surface morphology, and much lower bow than for similar structures grown on sapphire. Along with other wafer shape issues, low bow is important for achieving high-yielding and advanced device fabrication, says Kyma. Wafer shape control, including GaN cracking or entire wafer breakage, is a major problem with traditional approaches on large-diameter wafers and is one of the major obstacles for the WBGS industry, limiting achievable economies of scale.
The firms say that there is clear potential to extend the GaN-on-QST template approach to full GaN boule manufacturing. Accordingly, they have already won support on two separate federal research projects: (1) to develop processes for manufacturing cost-effective large-diameter high-growth-rate GaN-on-QST templates up to 8" diameter, and (2) to take that approach to the next level to create 4"- and 6"-diameter free-standing GaN substrates.
In the first project, Kyma is developing an 8"-diameter GaN growth tool that is designed to produce uniform low-defect-density GaN-on-QST wafers in GaN thicknesses up to 100 microns at a fast-cycle time which will support low tool cost of ownership (CoO). Kyma is already teamed with a leading OEM tool maker to support rapid market penetration of the technology once the team further advances the growth process and proves its ability to support high-performance device manufacturing. Kyma says that its device partners include leading US universities and multiple large device manufacturers.
In the second project, Kyma will create low-defect-density GaN boules and fabricate 4" and 6" substrates from them. The substrates will be made available to leading US device developers to prove the ability to support high-performance 1200V vertical power electronic device operation.
"We are very excited for Kyma to integrate its rapid GaN growth process on our high-performance substrate technology QST for delivering low-defect-density and large-diameter GaN wafers to the device manufacturers," says Quora's president & CEO Cem Basceri. "This special class of material will hopefully improve the existing device processes, designs, and performances, and also unlock new applications," he adds.
"We believe they have a game-changing baseline materials technology that will make a major impact on GaN-based LED, high-power-switching and RF device markets," comments Kyma's president & CEO Keith Evans. "By combining Kyma's advanced and high-growth-rate GaN technology with Quora's QST technology, we have the potential to help device manufacturers to accelerate their roadmaps for making higher performance devices at lower cost."
