Monolithically Integrated Logic Circuits Based on p-NiO Gated E-Mode GaN HEMTs
Chuanqi Pan, Xinxin Yu, Fan Li, Hehe Gong, Denggui Wang, Jianjun Zhou, Zhonghui Li, Wen Liu, Dunjun Chen, Shulin Gu, Youdou Zheng, Rong Zhang, Jiandong Ye
Abstract
High-performance GaN based one-chip direct coupled field-effect-transistor logic (DCFL) circuits were demonstrated, in which enhancement-mode (E-mode) GaN high electron mobility transistors (HEMTs) were formed simultaneously with depletion-mode (D-mode) components through the selective-area growth of p-NiO gates at room temperature by sputtering. The process boasts advantages such as a low thermal budget cost, eliminating the need for high-temperature regrowth of p-GaN, and preventing dry-etch damage. The E-mode HEMT showcases a high current density of 1.3 A/mm, a positive threshold voltage of 0.83 V, and an ON-OFF current ratio of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${7}.{24}\times {10} ^{{8}}$ </tex-math></inline-formula> , which enable input/output logic level matching with a low drive/load ratio of 1.0. The E/D-mode inverter exhibits substantial logic-low and logic-high noise margins of 2.09 V and 2.45 V, respectively, a logic voltage swing of 4.78 V, a switching threshold of 2.45 V and a voltage gain of 42 at a supply voltage of 5.0 V. With the demonstrated capability to drive power switches, this architecture provides an elegant solution for high-frequency power switching applications.