Digital Integrated Circuits on an E-Mode GaN Power HEMT Platform

GaN-based digital integrated circuits (ICs) are realized on a 6-inch GaN-on-Si power high-electron-mobility transistor (HEMT) platform by monolithic integration of enhancement/depletion-mode HEMTs using a 0.5-mu m gate technology. A direct-coupled FET logic inverter and a 101-stage ring oscillator are fabricated and characterized. The inverter exhibits a large input voltage swing, wide noise margin, and high temperature stability, while the ring oscillator features a small propagation delay of 0.1 ns/stage under a supply voltage of 4 V. These digital ICs can operate properly up to at least 200 degrees C and show great potential for GaN smart power IC applications.