(Invited) Development of 3-inch AlN Single Crystal Substrates

Aluminum nitride (AlN) substrates with diameter of 2-inch are available at large quantities. The further commercialization of the AlN as a substrate for the ultra-wide bandgap (UWBG) electronics depends on its size (≥ 100 mm), cost, and substrate properties. We developed a method based on the Physical Vapor Transport (PVT) capable of growing large AlN bulk crystals. The resulting AlN substrate diameter was increased from 2-inch to 3-inch. The 3-inch AlN is viewed as intermediate phase for realization of 100 mm AlN. The 3-inch AlN substrate exhibit very good crystallinity and excellent UV transparency.