Ferroelectricity in Polar Polymer-based FETs: A Hysteresis Analysis

Published

January 15, 2018

Author(s)

Vasileia Georgiou, Dmitry Veksler, Jason Campbell, Jason Ryan, Pragya Shrestha, D. E. Ioannou, Kin P. Cheung

Abstract

There is an increasing number of reports on polar polymer-based Ferroelectric Field Effect Transistors (FeFETs), where the hysteresis of the drain current - gate voltage (Id-Vg) curve is investigated as the result of the ferroelectric polarization effect. However, separating ferroelectric effect from many of the factors (such as charge injection/trapping and the presence of mobile ions in the polymer) that confound interpretation is still confusing and controversial. This work presents a methodology to reliably identify the confounding factors which obscure the polarization effect in FeFETs. Careful observation of the Id-Vg curves, as well as monitoring the Id-Vg hysteresis and flat band voltage shift as a function of temperature and sweep frequency identifies the dominant mechanism. This methodology is demonstrated using 15-nm thick high glass transition temperature polar polymer-based FeFETs. In these devices, room temperature hysteresis is largely a consequence of charge trapping and mobile ions, while ferroelectric polarization is observed at elevated temperatures. This methodology can be used to unambiguously prove the effect of ferroelectric polarization in FeFETs.

Citation

Advanced Functional Materials

Pub Type

Journals

Keywords

Id-Vg hysteresis, flat band voltage shift, ferroelectric effect, mobile ions, charge trapping

Citation

Georgiou, V. , Veksler, D. , Campbell, J. , Ryan, J. , Shrestha, P. , Ioannou, D. and Cheung, K. (2018), Ferroelectricity in Polar Polymer-based FETs: A Hysteresis Analysis, Advanced Functional Materials (Accessed April 24, 2024)