Characterization of Parasitic Resistances of AlN/GaN/AlGaN HEMTs Through TCAD-Based Device Simulations and On-Wafer Measurements

Abstract

This paper shows a detailed characterization and estimation of the temperature-dependent on-resistance $R _{\mathrm {ON}}~( T )$ of AlN/GaN/AlGaN high electron-mobility transistors (HEMTs) through dc and low-frequency (LF) S-parameter measurements. The measurements are carried out at different chuck temperatures $( T _{\mathrm {chuck}} )$ and the $R _{\mathrm {ON}}~( T )$ is calculated for different values of gate-source bias $( V _{\mathrm {GS}} )$ of HEMT grown on a silicon carbide (SiC) substrate. Furthermore, we also present the two-dimensional (2-D) physics-based numerical simulation results for the $R _{\mathrm {ON}}~( T )$ extraction of this device. Knowing $R _{\mathrm {ON}}~( T )$ values of the device for different source-drain lengths $( L _{\mathrm {SD}} )$ , we propose a simplified method to extract the temperature-dependent series contact resistance $R _{\mathrm {se}}~( T )$ and channel sheet resistance $R _{\mathrm {sh}}~( T )$ of the GaN HEMT technology.