Extraction of net interfacial polarization charge from Al0.54In0.12Ga0.34N/GaN high electron mobility transistors grown by metalorganic chemical vapor deposition

摘要

AlInGaN materials show promise for use in GaN-based heterojunction devices. The growth of these materials has developed to the point where they are beginning to see implementation in high electron mobility transistors (HEMTs) and light emitting diodes. However, the electrical properties of these materials are still poorly understood, especially as related to the net polarization charge at the AlInGaN/GaN interface (Q(net)). All theoretical calculations of Q(net) share the same weakness: dependence upon polarization bowing parameters, which describe the deviation in Q(net) from Vegard's law. In this study, direct analysis of Q(net) for AlInGaN/GaN HEMTs is reported as extracted from C-V, I-V, and Hall measurements performed on samples grown by metalorganic chemical vapor deposition. An average value for Q(net) is calculated to be 2.015 × 10 C/cm, with just 6.5% variation between measurement techniques.