Study of two‐dimensional electron gas in AlGaN channel HEMTs with high crystalline quality

Abstract

AbstractEpitaxial structures of AlGaN channel high electron mobility transistors (HEMTs) were grown on sapphire and AlN substrates. Reduction in the full width at half maximum of X‐ray rocking curve for (10‐12) peak of the AlGaN channel layer owing to the reduction of threading dislocation densities resulted in a sharp decrease in the sheet resistance of 2‐dimensional electron gas (2DEG). In the case of AlGaN channel HEMTs, it was found that improvement of the crystalline quality of AlGaN channel layers is essential to the reduction of the sheet resistance of 2DEG. The use of AlN substrates resulted in improved crystalline quality of the AlGaN layer and lower 2DEG resistance, suggesting the high potential of AlN substrates for AlGaN channel HEMTs (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)