Microwave electronics device applications of AlGaN GaN heterostructures

One thrust in the recent AlGaN/GaN based HFET development hinges on the use of SiC substrates for the growth of the AlGaN/GaN heterostructures. We have achieved G(m) and maximum drain current (I-max) as high as 222 mS mm(-1) and 1.71 A mm(-1) for HFETs grown on n-SiC. The HFETs on p-SiC have also shown G(m) and I-max of 230 mS mm(-1) and 1.43 A mm(-1). These devices exhibited cut-off frequency (f(t)) and frequency of oscillation (f(max)) of 55 and 56 GHz for HFETs on p-SiC, further demonstrating the applicability of AlGaN/GaN-based HFETs in high power microwave frequency range. The availability of high quality AlGaN/GaN heterostructure has also permitted the implementation of such new device concept as metal-insulator-semiconductor FETs (MISFETs). Our MISFETs have shown low gate leakage in +/-6 V gate bias range with G(m) as high as 86 mS mm(-1). (C) 1999 Elsevier Science S.A. All rights reserved.