Ferroelectricity in Polar Polymer‐Based FETs: A Hysteresis Analysis. (15th January 2018)

• Record Type: Journal Article
• Authors: Georgiou, Vasileia; Veksler, Dmitry; Campbell, Jason P.; Shrestha, Pragya R.; Ryan, Jason T.; Ioannou, Dimitris E.; Cheung, Kin P.
• Is Part Of: Advanced functional materials. Volume 28:Number 10(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-01-15
• Subjects: charge trapping -- ferroelectric effects -- flat band voltage shifts -- Id–Vg hysteresis -- mobile ions; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.201705250
• Languages: English
• ISSNs: 1616-301X

Abstract

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 ( I d – V g ) 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 I d – V g curves, as well as monitoring the I d – V g hysteresis and flat band voltage shift as a function of temperature and sweep frequency, identifies the dominant mechanism. This methodology is demonstrated by 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. Abstract : Separating ferroelectric effect from many of the factors, such as charge injection/trapping and the presence of mobile ions in the polymer, is still confusing and controversial. This work presents an easy way to follow methodology to reliably identify the confounding factors which obscure the polarization effect in ferroelectric field effect transistors.