Quartz-free hydride vapor phase epitaxy for production of large size GaN-on-GaN epitaxial wafers

GaN-on-GaN epitaxial growth on 4 and 6 inch wafers was demonstrated using a new mass-production-type quartz-free hydride vapor phase epitaxy (QF-HVPE) system. The thickness, effective donor density, and near-band-edge photoluminescence peak intensity were confirmed to be uniform for 4 inch wafers. In addition, a new QF-HVPE system enabled the growth of extremely pure GaN crystals with a C concentration lower than 1 × 1014 cm−3, enabling a wide range of doping control from 1 × 1014 to 1 × 1018 cm−3. The resultant GaN wafers were free from C-induced mobility collapse and exhibited record-high room-temperature and maximum mobilities of 1591 cm2 V−1 s−1 and 18,175 cm2 V−1 s−1 at 35 K, respectively.