Dual Current and Voltage Sensitivity Temperature Sensor Based on Lateral p-GaN/AlGaN/GaN Hybrid Anode Diode

Abstract

In this work, a p-GaN/AlGaN/GaN hybrid anode diode (HAD) temperature sensor was fabricated by using hydrogen plasma treatment. The zero-temperature coefficient (ZTC) is about 0.7 V from the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}$ </tex-math></inline-formula> – <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}$ </tex-math></inline-formula> characteristics measured at various temperatures. At the forward region below the ZTC bias point, the anode voltage ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${V}_{{\mathrm {A}}}$ </tex-math></inline-formula> ) at a specific anode current density ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{{\mathrm {A}}}$ </tex-math></inline-formula> ) decreases linearly with the increase of temperature, resulting in a sensitivity ranging from 1.64 mV/K (10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−5</sup> mA/mm) to 0.69 mV/K (10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−2</sup> mA/mm). The leakage current at the reverse bias also presents a temperature-dependent behavior with a sensitivity ranging from 16.76 mA/K (−100 V) to 27.94 mA/K (−5 V). The experimental results can be interpreted well by the two-dimensional variable range hopping model.