脈沖激光沉積法（PLD）制備非晶態BZN薄膜的研究

目  錄
第1章 緒 論 1
1.1 電介質材料 1
1.2 微波介質材料 1
1.3 BZN焦綠石 2
1.3.1 焦綠石結構 2
1.3.2 BZN陶瓷的相結構和微波性質 2
1.3.3 BZN薄膜的研究現狀 3
1.3.4 BZN薄膜介電可調機理 4
1.4 本論文研究的選題依據和任務 4
第2章 BZN陶瓷靶材的制備與表征 6
2.1 BZN陶瓷靶材的制備工藝 6
2.2 BZN陶瓷樣品的XRD分析 8
2.3 陶瓷樣品SEM分析 9
2.4 陶瓷樣品介電性能表征 10
2.5 BZN陶瓷靶材的制備 12
2.6 本章小結 14
第3章 Bi1.5ZnNb1.5O7薄膜的制備 15
3.1 PLD工藝簡介 15
3.2 PLD制備BZN薄膜的工藝 18
3.2.1 沉積參數 18
3.2.2 制備操作流程 18
3.2.3 薄膜制備中氧壓的控制 18
3.3 后退火處理 19
3.4 Bi1.5ZnNb1.5O7薄膜的結構和形貌 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 本章小結 25
第4章 Bi1.5ZnNb1.5O7薄膜的電學性能 26
4.1 Bi1.5ZnNb1.5O7薄膜介電頻譜分析 26
4.2 Bi1.5ZnNb1.5O7薄膜漏電流特性 29
4.3 影響薄膜電性能的因素 30
4.4薄膜性能的優化 31
4.5 本章小結 31
第5章 結論與展望 32
致  謝 33
參考文獻 35

摘  要
 Bi2O3-ZnO-Nb2O5(BZN)系列焦綠結構陶瓷由于具有適中的介電常數和低的介電損耗而廣泛用于低溫燒結多層陶瓷電容器和微波介質器件中。近年來，研究者發現BZN薄膜具有很好的微波介電可調特性，使得BZN體系在可變頻率微波集成器件等方面有廣闊的應用前景，成為學術界和產業界競相研究的熱點。
 本文采用脈沖激光沉積法（PLD）在鍍Pt底電極的Si基片上成功制備出了Bi1.5ZnNb1.5O7的非晶態薄膜。以制備Bi1.5ZnNb1.5O7薄膜工藝中氧壓和后處理的退火溫度為研究重點，分別研究了不同氧壓以及不同退火溫度對Bi1.5ZnNb1.5O7薄膜結構和性能產生的影響。SEM和XRD分析結果表明在室溫下沉積的Bi1.5ZnNb1.5O7薄膜是非晶態的，退火溫度小于200℃時處理的Bi1.5ZnNb1.5O7薄膜仍是非晶態的；隨著氧壓的升高，Bi1.5ZnNb1.5O7薄膜的厚度增加，表面粗糙度也相應增加，而且薄膜致密性逐漸變差。介電性能測試結果表明Bi1.5ZnNb1.5O7薄膜在150℃進行后退火處理擁有較好的介電性能。在1Pa氧壓、150℃退火處理的Bi1.5ZnNb1.5O7薄膜，在10 kHz頻率下介電常數60.1，損耗為0.0083，而且在0.3 MV/cm的直流電場下的漏電流密度為1×10-7A/cm2。

關 鍵 詞：BZN；PLD；非晶態；
 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, low 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.

關 鍵 詞：BZN；PLD；非晶態；
 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, low 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. BZN 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