Optimized Device Geometry of Normally-On Field-Plate AlGaN/GaN High Electron Mobility Transistors for High Breakdown Performance Using TCAD Simulation

Abstract

This study presents the optimization of the lateral device geometry and thickness of the channel and barrier layers of AlGaN/GaN high electron mobility transistors (HEMTs) for the enhancement of breakdown voltage (VBR) characteristics using a TCAD simulation. The effect of device geometry on the device performance was explored by varying the device design parameters, such as the field plate length (LFP), gate-to-drain length (LGD), gate-to-source length (LGS), gate length (LG), thickness of the Si3N4 passivation layer (Tox), thickness of the GaN channel (Tch), and AlGaN barrier (Tbarrier). The VBR was estimated from the off-state drain current versus the drain voltage (IDS–VDS) curve, and it exhibited a strong dependence on the length and thickness of the parameters. The optimum values of VBR for all the device’s geometrical parameters were evaluated, based on which, an optimized device geometry of the field-plated AlGaN/GaN HEMT structure was proposed. The optimized AlGaN/GaN HEMT structure exhibited VBR = 970 V at IGS = 0.14 A/mm, which was considerably higher than the results obtained in previous studies. The results obtained in this study could provide vital information for the selection of the device geometry for the implementation of HEMT structures.

AlGaN as an electron transport layer for wide-bandgap perovskite solar cells

“…Table III shows the structure and parameters of the devices used in the simulation. [45][46][47][48][49][50][51][52] As referenced by the report in Ref. 23, interface layers were set on both sides of the perovskite layer.…”

“…Table III. Device simulation model for SCAPS and material parameters [45][46][47][48][49][50][51][52] an energy spike appears and efficiency is maximized when the electron affinity of AlGaN is less than 3.2 eV. In the case of perovskite materials with other energy bands, it is expected that the efficiency will increase by adjusting the Al composition of AlGaN.…”

Simulation modelling of III‐Nitride / β ‐Ga 2 O 3 Nano‐HEMT for microwave and millimetre wave applications

“…A protective passivation layer of Si 3 N 4 is used to prevent surface state contamination and traps 25,26,27 . The parasitic capacitance under the gate terminal is lowered due to its reduced size and smaller field plate area 28–31 . The proposed device employing without field‐plate with gate recessed depths of 25, 30, and 35 nm and with field‐plate structure of 30 nm recessed gate depth are taken into consideration in this piece of research.…”

Correlation of Crystal Defects with Device Performance of AlGaN/GaN High-Electron-Mobility Transistors Fabricated on Silicon and Sapphire Substrates

“…Group III nitride-based heterostructures have attracted considerable interest for their promising applications in the development of high-performance high-electron-mobility transistors (HEMTs), ultraviolet light-emitting diodes, optical data storage, and related devices because of their large band gap, high bulk mobility, and high critical field strength [1][2][3][4][5]. In particular, AlGaN/GaN heterostructures are extensively employed in HEMTs for highfrequency and high-power devices, as well as in biological and chemical sensors and piezotronics [6,7]. In AlGaN/GaN HEMTs, the two-dimensional electron gas (2DEG) is originated due to the spontaneous and piezoelectric polarization induced sheet charge formed at the AlGaN/GaN heterojunction [8,9].…”