Thickness Scaling of Pb(Zr,Ti)O 3 Thin Films and Pt Electrodes for High Density FeRAM Devices

Abstract

This article describes the scaling and performance issues for future high density ferroelectric non-volatile memories (FeRAM) using sub-100 nm Pb(Zr,Ti)O 3 thin films by chemical deposition process and ultra thin electrode stack. Two separate approaches are discussed. The first approach involves the scalability of electrode stack. It is observed that crystallization and ferroelectric behavior of PZT thin films were improved with increasing Pt thickness. However, PZT thin films till showed high ferroelectric performance even on 30 nm-thick Pt electrodes. The second approach presents high ferroelectric performance of the thickness scaled PZT thin films (∼50 nm) on 30 nm-thick Pt electrodes. The switching performance of these thickness scaled PZT thin films showed below 1 V operation with high polarization value (> 30 w C/cm 2 ), implying the possibility to realize 32Mb FRAM devices and beyond.