Current percolation path impacting switching behavior of ferroelectric FETs
Franz Müller, Maximilian Lederer, Ricardo Olivo, Tarek Ali, Raik Hoffmann, Halid Mulaosmanovic, Sven Beyer, Stefan Dünkel, Johannes Müller, Stefan Müller, Konrad Seidel, Gerald Gerlach
Abstract
The difference in the switching behavior of program and erase operation in hafnium oxide based ferroelectric FETs (FeFETs) highlights insufficiency of models solely based on the ferroelectric hysteresis. In this work, program and erase characteristics across various FeFET dimensions have been compared in order to investigate the scaling-dependent switching behavior. A simulation model comprising the FeFET channel size, effective grain size, phase and orientation was developed to mimic the field controlled switching of ferroelectric grains and their effect on resulting current percolation paths. Finally, the impact of FET channel length L and width W was systematically analyzed both experimentally and using the developed model for both memory states. Investigations show how systematic W and L scaling can be utilized to tune switching behavior from abrupt digital-like, suitable for robust memory applications, to gradual analog-like, favorable in neuromorphic applications.