The interface screening model as origin of imprint in PbZrxTi1−xO3 thin films. II. Numerical simulation and verification

Abstract

In this article, the interface screening model is theoretically discussed which explains imprint in ferroelectric thin films caused by a large electric field within a surface layer with deteriorated ferroelectric properties. During aging this field is gradually screened by electronic charges. Different screening mechanisms such as charge injection from the electrodes into the film as well as charge separation within the surface layer are considered by implementing a numerical simulation based on the different screening mechanisms. A comparison between experimental and simulation results is presented. The best agreement between experiment and simulation is obtained for a Frenkel–Poole type charge separation mechanism within the surface layer. The simulation results indicate relatively shallow trap states (0.35 eV) and a surface layer extension of approximately 5 nm.

Thickness profiles through fatigued bulk ceramic lead zirconate titanate

“…15,18,57,58 As we showed previously, this is also true for bulk ferroelectrics. 59,60 In this paper, we chose samples with silver and platinum electrodes with the intent of having large differences in work functions of the metal electrodes and in order to test their relative effect on fatigue in a bulk material.…”

Modeling and simulation of low power ferroelectric non-volatile memory tunnel field effect transistors using silicon-doped hafnium oxide as gate dielectric

“…The properties of two wellknown perovskite ferroelectrics, Lead Zirconate Titanate (PZT) and Strontium Barium Titanate (SBT), is compared with Si:HfO 2 in Table 1. The recently discovered ferroelectric thin film, Si:HfO 2 [28,6], has a relatively high coercive field that ensures a large memory window [29][30][31][32][33][34][35][36][37][38][39].…”

Metal-ferroelectric-metal heterostructures with Schottky contacts. I. Influence of the ferroelectric properties

“…Screening the vast literature on this topic [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] the transport mechanisms can be grouped in two major categories: i) interface controlled mechanisms based on Schottky emission or Fowler-Nordheim tunneling and ii) bulk controlled mechanisms such as ohmic, space charge limited currents, Pool-Frenkel emission, ionic conduction, or a combination of them. However, the main dilemma arises from the question whatever the ferroelectric film should be treated as an insulator or as a semiconductor.…”