摘要
通过将溶胶凝胶法制备的锆钛酸铅(PZT)在非晶态和多晶态进行刻蚀,对比未经刻蚀的PZT性能,研究了集成工艺中湿法刻蚀造成极化和耐久性能退化的机理.PZT的结晶图谱和表面形貌分析发现,湿法刻蚀中产生的非铁电成分由于具有较小的介电常数,降低了铁电材料上分担的有效测试电压,导致刻蚀后PZT极化能力的降低.未刻蚀的PZT翻转1011次后极化值损失约3%,而刻蚀后极化值减小量大于5%.随着尺寸的减小,耐久特性的降低更为明显,100μm×100μm的PZT极化值减小量约为500μm×500μm样品的3倍.高温过程中由于湿法刻蚀而产生的缺陷和空隙在PZT内部重新分布,外加电压下有更多的电子被缺陷和空隙束缚而产生内建电场并钉扎铁电畴,不同器件尺寸的PZT内部缺陷和空隙浓度的变化不同,导致耐久特性随PZT器件尺寸而不同.利用压电特性参数与极化强度的关系,可以解释湿法刻蚀对压电特性造成损伤的原因.
Amorphous and polycrystalline lead zirconium titanate（PZT） films prepared by means of sol-gel were etched into different sizes.Compared with the properties of unetched PZT,polarization and endurance properties of PZT were found to degrade after wet etching process.Mechanisms of etching damage were investigated.Phase patterns and surface topologies of PZT were examined,and results show that,non-ferroelectric components are formed in wet etching process,and their permittivity is smaller than that of PZT,which reduces effective applied voltage on the ferroelectric device and causes polarization to decrease.After 1011 fatigue cycles,about 3% of initial remnant polarization（Pr） is found in unetched PZT.While in etched PZT devices,the Pr loss is more than 5%.Endurance property is found to degrade more severely in smaller devices.The Pr loss in 100 μm×100 μm PZT device is about 3 times of the value found in 500 μm×500 μm samples.Defects and vacancies will be generated in wet etching process.At high temperature,they will redistribute and trap more electrons,which will generate internal electric field and pin the domains.Concentrations of defects and vacancies vary with the size of PZT and result in different values of endurance performance.The relationship of piezoelectric parameters and polarization can explain the reason for degradation of piezoelectricity.
出处
《纳米技术与精密工程》
EI
CAS
CSCD
2011年第4期357-363,共7页
Nanotechnology and Precision Engineering
基金
国家高技术研究发展计划(863计划)资助项目(2009AA01Z115)
国家科技重大专项资助(2009ZX02023-1-3)
关键词
锆钛酸铅
湿法刻蚀
性能退化
尺寸
刻蚀损伤
lead zirconium titanate
wet etching
property degradation
size
etching damage
