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

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 Ω · 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 kQ·mm. Complementary logic inverters fabricated with this technologyyield a record maximum voltage gain of ~27 V/V at an input voltage of 0.59 V with VDD = 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.