Unified Mechanism for Positive- and Negative-Bias Temperature Instability in GaN MOSFETs
Author(s)
Guo, Alex
del Alamo, Jesus A.
Date Issued
May 2017
Journal
IEEE Transactions on Electron Devices
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Citation
Guo, Alex and Jesús A. del Alamo. "Unified Mechanism for Positive- and Negative-Bias Temperature Instability in GaN MOSFETs." IEEE Transactions on Electron Devices 64, 5 (May 2017): 2142 - 2147 © 2017 IEEE
Version
Author's final manuscript
Abstract
We present a comprehensive study of bias temperature instability (BTI) in GaN MOSFETs under moderate positive and negative gate bias stress. We investigate the evolution of threshold voltage (V T ), maximum transconductance (g m,max ), and subthreshold swing (S). Our results show a universal continuous, symmetrical, and reversible VT shift and gm,max change as gate stress voltage (VGS,stress) increases from -5 to 5V at room temperature. The time evolution of V T is well described by a power law model. The voltage dependence, time dependence, and temperature dependence of our results suggest that for moderate gate bias stress, positive BTI and negative BTI are due to a single reversible mechanism. This is electron trapping/detrapping in preexisting oxide traps that form a defect band very close to the GaN/oxide interface and extend in energy beyond the conduction band edge of GaN and below the Fermi level at the channel surface at 0 V.
MIT Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1109/ted.2017.2686840
