Development of a 2-inch GaN wafer by using the oxide vapor phase epitaxy method

Abstract

From the previous studies, one of the challenges in the oxide vapor phase epitaxy (OVPE) method was suppressing poly-crystal generation for thick GaN growth. In this study, thick GaN growth was realized by controlling the supersaturation ratio using thermodynamic analysis, and an OVPE-GaN wafer of 300 μm-thick was obtained. As a result of evaluating the quality of the OVPE-GaN wafer, it was confirmed that both the high oxygen concentration and the high crystallinity were achieved. The resistivity was 7.75 × 10−4 Ω cm and the threading dislocation density (TDD) was 8.8 × 104 cm−2. It was newly found that the OVPE method can reduce TDD from the order of 106 cm−2 to the order of 104 cm−2 with a grown thickness of less than 500 μm. From these results, it was proved that the OVPE method has a great potential of manufacturing low resistivity and low TDD GaN wafers.