Regrowth-Free GaN-Based Complementary Logic on a Si Substrate

Abstract

This paper demonstrates a complementary logic circuit (an inverter) on a GaN-on-Si platform without the use of regrowth technology. Both n-channel and p-channel GaN transistors are monolithically integrated on a GaN/AlGaN/GaN double heterostructure. N-channel FETs show enhancement-mode (E-mode) operation with a threshold voltage around 0.2 V, ON- OFF current ratio of 107 and RON of $6~\Omega \cdot \text {mm}$ , while the p-channel FETs show E-mode operation with Vth of −1 V, ON- OFF current ratio of 104 and RON of 2.3 $\text{k}\Omega \cdot \text {mm}$ . Complementary logic inverters fabricated with this technology yield a record maximum voltage gain of ~27 V/V at an input voltage of 0.59 V with $\text{V}_{\text {DD}}={5}$ V. Excellent transfer characteristics have been obtained up to 300 °C operating temperatures, which demonstrates the suitability of this technology for low-power high-temperature electronic applications.