Theoretical Limits of the Matching Bandwidth and Output Power of AlScN-Based HEMTs
Open Access
- 30 November 2023
- journal article
- research article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in IEEE Transactions on Electron Devices
- Vol. 71 (3) , 1670-1675
Abstract
In this work, the simultaneously achievable matching bandwidth and output power of AlScN-based high electron mobility transistors (HEMTs) are derived and compared to conventional AlGaN, GaAs, and Si devices. Moll’s method is used to extract time delays resulting in carrier velocities close to 1 $\times$ 10 $^{\text{7}}$ cm/s for sheet carrier densities $\ge$ 1.5 $\times$ 10 $^{\text{13}}$ cm $^{-\text{2}}$ . Subsequently, theoretical current densities of 2.5–4 A/mm and a maximum transconductance higher than 600 mS/mm are derived for low barrier thicknesses of 5–10 nm and Sc-concentrations of 5%–20%. The matching bandwidth is estimated by the Bode–Fano criterion and connected to the output power of the transistor by the power-bandwidth product, which accounts for both parameters simultaneously. AlScN-based devices are found to exhibit a 4.5-times higher power-bandwidth product compared to conventional AlGaN-based HEMTs, quantifying the enormous, theoretical limits. Experimental data already show an improvement by a factor of 1.45 for AlScN-based devices, even in this early stage of development, which proves their superior properties, when aiming for wideband high-power millimeter-wave (mm-wave) devices.Keywords
Funding Information
- German Federal Ministry of Defense, BMVg, and Federal Office of Bundeswehr Equipment, Information Technology and In-Service Support BAAINBw
- German Federal Ministry of Education and Research (BMBF) within the Project EdgeLimit-Green ICT
- Fraunhofer Internal Programs SCALING
This publication has 35 references indexed in Scilit:
- High Power Density ScAlN-Based Heterostructure FETs for mm-Wave Applications2019
- ScAlN/GaN High-Electron-Mobility Transistors With 2.4-A/mm Current Density and 0.67-S/mm TransconductanceIEEE Electron Device Letters, 2019
- Demonstration of Constant 8 W/mm Power Density at 10, 30, and 94 GHz in State-of-the-Art Millimeter-Wave N-Polar GaN MISHEMTsIEEE Transactions on Electron Devices, 2017
- Density-dependent electron transport and precise modeling of GaN high electron mobility transistorsApplied Physics Letters, 2015
- High efficiency Ka-band Gallium Nitride power amplifier MMICs2013
- InAlN/AlN/GaN HEMTs With Regrown Ohmic Contacts and $f_{T}$ of 370 GHzIEEE Electron Device Letters, 2012
- Effect of Optical Phonon Scattering on the Performance of GaN TransistorsIEEE Electron Device Letters, 2012
- High-Performance AlN/GaN HEMTs on Sapphire Substrate With an Oxidized Gate InsulatorIEEE Electron Device Letters, 2011
- AlN/GaN Insulated-Gate HFETs Using Cat-CVD SiNIEEE Electron Device Letters, 2006
- Bulk GaN and AlGaN∕GaN heterostructure drift velocity measurements and comparison to theoretical modelsJournal of Applied Physics, 2005