Impact of Rapid-Thermal-Annealing Temperature on the Polarization Characteristics of a PZT-Based Ferroelectric Capacitor

Changhwan Shin,Hanyeong Yu

doi:10.3390/electronics10111324

Abstract

A metal-ferroelectric-metal (MFM) capacitor was fabricated to investigate the effect of the rate-of-change of temperature in the rapid thermal annealing (RTA) process on the physical properties of the MFM capacitor’s ferroelectric layer [lead zirconate oxide (PZT)]. Remnant polarization (2 × Pr) is measured and monitored while performing the RTA process at 500 °C–700 °C. It turned out that, for a given target/final temperature in the RTA process, 2Pr of the ferroelectric layer decreases with a higher rate-of-change of temperature. This can provide a way to adjust the properties of the PZT layer, depending on the RTA process condition (i.e., using various rate-of-changes of temperature) for a given final/target temperature.

Highlights

Unlike conventional dielectric materials, ferroelectric materials have the property of maintaining electrical polarization without an external voltage
Pb(Zr1-x Tix )O3 (PZT) has been mainly used in Ferroelectric Random Access Memory (FeRAM), Pyroelectric Infrared (IR) Sensors, Surface Acoustic Wave (SAW) devices, and so on [1,2,3,4,5]
Ferroelectric films are widely used in electronics, and their properties vary greatly depending on synthesis conditions, the thickness of a ferroelectric layer, substrate/electrode materials on the top/bottom of the ferroelectric layer, and so on [8,9,10,11,12,13,14,15,16]

Summary

Introduction

Ferroelectric materials have the property of maintaining electrical polarization without an external voltage. Based on this unique characteristic, they have been widely used in electronics. In the previous studies [17,18], it was investigated that the hysteresis of the polarization characteristic was increased at a higher annealing temperature. Afterwards, a follow-up study was done to investigate the dependence of the characteristics of a Pt/PZT/Pt capacitor on various rapid thermal annealing (RTA) temperatures. Two different conditions on how to increase RTA temperature were suggested and set up; the target RTA temperatures were set/chosen in the range of 500 ◦ C to 700 ◦ C by 100 ◦ C.

Fabrication and Measurement for

Results and Discussion

Conclusions