Modulating Self-Heating Effects in GaN HEMTs Using Slant Field Plate

The self-heating effect in electronic devices can lead to localized hotspots, adversely affecting their performance and reliability, particularly in high-power-density devices like gallium nitride (GaN) high-electron-mobility transistors (HEMTs). In addition to enhancing heat dissipation, reducing heat generation through structural design can effectively modulate self-heating effects. This study investigates the modulation effect of an asymmetric slant field plate (FP) on self-heating in GaN HEMTs, using electro-thermal simulations based on the drift-diffusion model. Additionally, Monte Carlo (MC) simulations are employed to examine the influence of the slant FP on phonon ballistic transport under non-Fourier heat conduction. Results show that the slant FP smooths the potential distribution and reduces the maximum electric field intensity in the channel, thereby decreasing the maximum heat generation density. With a slant angle of 6° and an FP length of 1200 nm, the maximum heat generation density is reduced by 50%, and the hotspot temperature rise is lowered by 16%. By adjusting the characteristic size of the heat source, the slant FP further reduces near-junction thermal resistance, achieving the hotspot temperature reduction of over 30% under non-Fourier heat conduction. This work aims to deepen the understanding of self-heating effects in HEMT devices and explore a potential thermal management strategy.