GaN Bootstrapping Amplifier IC Operating at up to 800 °C Temperature

Abstract

A gallium nitride bootstrapping amplifier integrated circuit is demonstrated for high-temperature applications. The amplifier leverages bootstrapping gain-boosting technology and incorporates five monolithically integrated depletion-mode gallium nitride high electron mobility transistors, enabling an operation temperature up to 800°C in N2 environment. Those transistors feature a threshold voltage of approximately −2 V. Under a gate-to-source voltage of 5 V, the on-state current density decreased from 167 mA/mm at 25°C to 45 mA/mm at 800°C. At 25°C, the amplifier exhibits a DC gain of 26.3 dB with a unity gain frequency of 8.9 MHz. At 800°C, the amplifier delivers a DC gain of 31 dB and a unity gain frequency of 1.4 MHz. In addition, no significant degradation was observed after holding the transistor and amplifier unbiased for an hour at 800°C. This amplifier integrated circuit demonstrates the competitiveness of gallium nitride high electron mobility transistors as a promising technology for high-temperature electronics, up to 800°C.