화학공학소재연구정보센터
학회 한국재료학회
학술대회 2004년 가을 (11/05 ~ 11/05, 인하대학교)
권호 10권 2호
발표분야 세라믹스
제목 졸겔 방법으로 제작된 Pb(Zr,Ti)O3 박막의 열처리 과정에 의한 물리적, 전기적 특성 변화 효과 연구
초록 1. Introduction
Ferroelectric Pb(Zr,Ti)O3(PZT) thin films are strongly dependent on parameters such as composition, microstructure, orientation and the types of substrates used. It is still an important issue to prepare crack-free PZT films, obtainable through precisely controlling the processing conditions. This paper illustrates the preparation of crack-alleviated PZT thin films by manipulation of the heating period and rate.

2. Experimental
The films with different Zr/Ti ratio of 50:50 were prepared by spin-casting at 3000rpm for 30secs on Pt/Ti/SiO2/Si substrates. These films were dried at a temperature of 200℃ for 1min, following a pyrolysis procedure at 400℃ for 5mins. Three different method of film preparation was conducted-a single-step annealing process for 30mins in (a) O2 environment and (b) air ambient, and (c) a 2-step process carried out in air ambient, following a O2 annealing process, both conducted for 30mins.
Films with a thickness of 200nm were observed through cross-sectional images and its surface morphology at various annealing temperatures was characterized by scanning electron microscopy. An x-ray diffraction θ-2θ scans were used to investigate the crystallographic properties of the films. Measurements of the dielectric properties were carried out using HP4194A Impedance Analyzer and polarization-field hysteresis loops was extracted by an RT66A ferroelectric tester. Characterizations of the fatigue properties were conducted until 1×1010 switching cycles with an applied frequency of 1MHz.

3. Discussions
PZT films were preferably oriented to the (111) direction. Unlike the 2-step process, a 1-step process revealed (100)-oriented films at low annealing temperatures. Ferroelectric properties showed that films annealed at 600℃ possesses high remnant polarization and low coercive voltage. Films prepared by the 2-step heat-treatment revealed relatively enhanced polarization values, having a saturation property at low applied voltages and larger remnant polarizations. The compensation to oxygen content in the films are the main reason for such enhanced ferroelectric properties.
저자 심동현, 박재문, 남광우, 박광서
소속 서강대
키워드 강유전체; PZT 박막; 졸겔방법
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