High-Temperature Sensitivity of a Depletion-Mode AlGaN/GaN MIS-HEMT

Abstract

This article reports on the high-temperature (HT) operation (25 °C–400 °C) and temperature sensing mechanism of a depletion-mode AlGaN/GaN metal–insulator–semiconductor (MIS) high-electron-mobility transistor (depletion mode (D-mode) AlGaN/GaN MIS-HEMT) in GaN on Si technology. Our measurements and simulations show that the high sensitivity of the device is governed by traps at the GaN-cap/Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> interface and in the GaN buffer layer. At subthreshold operation, the device temperature sensitivity reaches 8.73%/K at a drain-to-source current ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${I}_{\mathrm{DS}}$ </tex-math></inline-formula> ) of 10 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{A}$ </tex-math></inline-formula> /mm. This is similar to the values reported for silicon devices, but in a much wider temperature range and at much higher current densities.