Numerical Optimization of On-Resistance and Transconductance in Depletion-Mode and Enhancement-Mode GaN HEMTs
- Resource Type
- Conference
- Authors
- Berdalovic, Ivan; Poljak, Mirko; Suligoj, Tomislav
- Source
- 2022 IEEE BiCMOS and Compound Semiconductor Integrated Circuits and Technology Symposium (BCICTS) BiCMOS and Compound Semiconductor Integrated Circuits and Technology Symposium (BCICTS), 2022 IEEE. :29-32 Oct, 2022
- Subject
- Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Fields, Waves and Electromagnetics
General Topics for Engineers
Photonics and Electrooptics
Power, Energy and Industry Applications
DH-HEMTs
Threshold voltage
Wide band gap semiconductors
MODFETs
Gallium nitride
Integrated circuit modeling
Voltage control
Power semiconductor devices
quantum well devices
gallium nitride
high electron mobility transistors
heterojunctions
two-dimensional electron gas
semiconductor device modeling
charge carrier mobility
- Language
- ISSN
- 2831-4999
In this paper, we use a numerical mobility modeling framework for GaN-based high electron mobility transistors (HEMTs) to examine the dependence of important design parameters such as on-resistance and transconductance on the device structure. The model is calibrated by matching previously published experimental mobility data for a depletion-mode AlGaN/AlN/GaN/AlGaN double-heterostructure (DH) HEMT to within ±10%. The structural parameters of the device are optimized and a minimum on-resistance of 541 Ω/□ is achieved with a mole fraction of 0.36 and thickness of 14 nm for the AlGaN barrier. A p-GaN cap is added to the initial structure to achieve enhancement-mode operation, and the impact of cap and barrier thickness on threshold voltage and on-resistance is discussed. The transconductance of enhancement-mode devices at an overvoltage of 8 V is improved from 1.58 to 2.59 mS/□ by simultaneously reducing the thickness of the p-GaN and AlGaN layers, thus increasing the gate capacitance while maintaining the same threshold voltage and on-resistance. The optimization procedure allows to obtain similar design parameters for the enhancement-mode HEMT as for the initial depletion-mode structure, proving that the addition of the p-GaN cap is an efficient way to increase the threshold voltage without compromising device performance.