High power and high gain AlGaN/GaN MIS‐HEMTs with high‐k dielectric layer

High power n-GaN/n-AlGaN/GaN metal-insulator-semi-conductor high electron mobility transistors (MIS-HEMTs) with high-k Ta2O5 dielectric layer were fabricated on a 3-inch S.I.-SiC substrate, for the first time. An n-GaN/n-AlGaN/GaN MIS-HEMTs with 400 V breakdown voltage were obtained by using Ta2O5 insulating layer/n-GaN capstructure. The single-chip GaN MIS-HEMTs amplifier with a Ta2O5 layer operated at 50 V achieve a high output power of 113 W with a linear gain of 16.3 dB at 2.5 GHz. We also investigated the RF stress reliability under the P3dB condition. The fluctuation of output power and drain current was lower than 5% even after 150 h stress test. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)