Technical Insight
Kyma looks to scale HVPE approach
Currently producing 2 inch GaN substrates from a native seed, Kyma Technologies' crystal process will be scaled up to 4 inches by the end of the decade, report Keith Gurnett and Tom Adams.
GaN devices are enjoying great commercial success, but their performance is still held back by the foreign substrates that are generally used as a basis for their manufacture. Switching to high-quality GaN substrates would cure this problem, but making this form of substrate is not easy. Because of GaN s high melting point (~2500 °C) and the incredible chemical stability of nitrogen gas, conventional liquid approaches such as those used for silicon and GaAs, where an ingot is pulled directly from a crystal melt, have only brought limited success. The GaN crystals produced by this method do have an excellent crystalline quality, but they are far too small for manufacturing purposes.
