摘 要:Bi2O3-ZnO-Nb2O5(BZN)系列焦绿结构陶瓷由于具有适中的介电常数和低的介电损耗而广泛用于低温烧结多层陶瓷电容器和微波介质器件中。近年来，研究者发现BZN薄膜具有很好的微波介电可调特性，使得BZN体系在可变频率微波集成器件等方面有广阔的应用前景，成为学术界和产业界竞相研究的热点。
本文采用脉冲激光沉积法（PLD）在镀Pt底电极的Si基片上成功制备出了Bi1.5ZnNb1.5O7的非晶态薄膜。以制备Bi1.5ZnNb1.5O7薄膜工艺中氧压和后处理的退火温度为研究重点，分别研究了不同氧压以及不同退火温度对Bi1.5ZnNb1.5O7薄膜结构和性能产生的影响。本论文由无忧论文网www.51lunwen.org整理提供SEM和XRD分析结果表明在室温下沉积的Bi1.5ZnNb1.5O7薄膜是非晶态的，退火温度小于200℃时处理的Bi1.5ZnNb1.5O7薄膜仍是非晶态的；随着氧压的升高，Bi1.5ZnNb1.5O7薄膜的厚度增加，表面粗糙度也相应增加，而且薄膜致密性逐渐变差。介电性能测试结果表明Bi1.5ZnNb1.5O7薄膜在150℃进行后退火处理拥有较好的介电性能。在1Pa氧压、150℃退火处理的Bi1.5ZnNb1.5O7薄膜，在10 kHz频率下介电常数60.1，损耗为0.0083，而且在0.3 MV/cm的直流电场下的漏电流密度为1×10-7A/cm2。
ABSTRACT:Bi2O3-ZnO-Nb2O5 (BZN) pyrochlore ceramics have been developed for low firing temperature capacitor and microwave dielectric device, because they posses a middle dielectric constant, www.51lunwen.orglow dielectric loss. In recent years large dielectric tunability of the BZN films was found and reported, which suggested that BZN had potential application for integrated microwave components. The investagation of BZN system, especially BZN films, has been drawing attention to the researchers from academic and industrials.
In this paper, amorphous BZN thin films were successfully prepared by pulsed laser deposition (PLD) on the Pt electrode coated Si substrates. The oxygen pressure and annealing temperature of the Bi1.5ZnNb1.5O7 films were investigated. Different oxygen pressure and different annealing temperature were experimented to show how they influence the dielectric properties and film structures. www.51lunwen.orgBZN thin films were all amorphous phase below 200 ℃ from the SEM and XRD results. With the increase of oxygen pressure, the thickness of Bi1.5ZnNb1.5O7 films increase accordingly, the morphology of BZN films surface becomes rougher and the less compact. Dielectric constant show that films annealed at 150℃ own the best dielectric property. Bi1.5ZnNb1.5O7 Films deposited at 1 Pa, annealed at 150℃ has the dielectric constant of 60.1, loss tangent of 0.0083 at the frequency of 10kHz, leakage current density of the Bi1.5ZnNb1.5O7 film is about 1×10-7A/cm2 at DC bias electrical field 0.3MV/cm.
KEY WORDS: BZN; PLD; Amorphous phase; Dielectric
目 录
第1章 绪 论 1
1.1 电介质材料 1
1.2 微波介质材料 1
1.3 BZN焦绿石 2
1.3.1 焦绿石结构 2
1.3.2 BZN陶瓷的相结构和微波性质 2
1.3.3 BZN薄膜的研究现状 3
1.3.4 BZN薄膜介电可调机理 4
1.4 本论文研究的选题依据和任务 4
第2章 BZN陶瓷靶材的制备与表征 6
2.1 BZN陶瓷靶材的制备工艺 6
2.2 BZN陶瓷样品的XRD分析 8
2.3 陶瓷样品SEM分析 9
2.4 陶瓷样品介电性能表征 10
2.5 BZN陶瓷靶材的制备 12
2.6 本章小结 14
第3章 Bi1.5ZnNb1.5O7薄膜的制备 15
3.1 PLD工艺简介 15
3.2 PLD制备BZN薄膜的工艺 18
3.2.1 沉积参数 18
3.2.2 制备操作流程 18
3.2.3 薄膜制备中氧压的控制 18
3.3 后退火处理 19
3.4 Bi1.5ZnNb1.5O7薄膜的结构和形貌 20
3.4.1 Bi1.5ZnNb1.5O7薄膜XRD分析 20
3.4.2 Bi1.5ZnNb1.5O7薄膜SEM分析 21
3.4.3 Bi1.5ZnNb1.5O7薄膜AFM分析 22
3.4.4 Bi1.5ZnNb1.5O7薄膜厚度分析 24
3.5 本章小结 25
第4章 Bi1.5ZnNb1.5O7薄膜的电学性能 26
4.1 Bi1.5ZnNb1.5O7薄膜介电频谱分析 26
4.2 Bi1.5ZnNb1.5O7薄膜漏电流特性 29
4.3 影响薄膜电性能的因素 30
4.4薄膜性能的优化 31
4.5 本章小结 31
第5章 结论与展望 32
致 谢 33
参考文献 35
主要参考文献
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2．Jong-Hyun Park, Woo-Sung Lee, Nak-Jin Seong, and Soon-Gil Yoon，“Bismuth-zinc-niobate embedded capacitors grown at room temperature for printed circuit board applications”，Appl. Phys. Lett.，www.51lunwen.org88, 192902 （2006）
3．K. Sudheendran, K. C. James Raju, Manoj K. Singh and Ram S. Katiyar,“Microwave dielectric and Raman scattering studies on bismuth zinc niobate thin films”，J. Appl. Phys.，104, 104104（2008）
