本文選題：脈沖激光沉積　切入點：BST薄膜　出處：《西安理工大學》2017年碩士論文

【摘要】：Ba1-xSrxTiO3(BST)薄膜材料因具有較高的介電常數(shù)及優(yōu)良的介電非線性效應,在動態(tài)隨機存儲器(DRAM)及電壓可調(diào)微波器件等方面具有良好的應用前景。為了與半導體工藝兼容,Si基BST薄膜成為當前研究熱點之一。目前這類BST薄膜存在的主要問題是薄膜的介電損耗較高,難以達到應用要求,而摻雜改性成為試圖解決這類問題的重要手段。本文首先采用固相反應法制備不同濃度Mn摻雜的Ba0.5Sr0.5TiO3陶瓷,作為脈沖激光沉積(PLD)法制備Ba0.5Sr0.5TiO3薄膜材料的靶材,隨后在Si(001)基片上探究了 BST/LNO/Si的制備工藝,并研究了 Mn摻雜對BST薄膜性能的影響。主要研究成果如下:(1)首先通過固相反應法制備了Ba0.5Sr0.5TiO3陶瓷,研究了燒結溫度對陶瓷靶材性能的影響并確定1300 ℃為最終燒結溫度。隨后制備了不同濃度Mn摻雜BST陶瓷,研究Mn摻雜濃度對BST陶瓷性能的影響。發(fā)現(xiàn)Mn摻雜會影響B(tài)ST陶瓷的介電性能,樣品介電常數(shù)隨Mn摻雜濃度升高而降低,介電損耗隨摻雜濃度升高先減小后增大。(2)采用自制靶材,在制備好的LNO/Si上用PLD法沉積BST薄膜,研究了 PLD法制備BST薄膜過程中沉積氣壓、激光能量和脈沖頻率對薄膜結構的影響,確定了 BST薄膜最優(yōu)的生長工藝為襯底溫度650 ℃、氧分壓5 Pa、激光能量220 mJ、脈沖頻率2 Hz、沉積時間 60 min、靶基距離 45 mm。。(3)研究了 Mn摻雜濃度變化對BST薄膜介電性能的影響。結果發(fā)現(xiàn)Mn摻雜薄膜樣品與陶瓷樣品的介電性能隨摻雜濃度變化有著相似的規(guī)律,即薄膜介電常數(shù)隨Mn摻雜濃度升高而降低,介電損耗隨摻雜濃度先減小后增大。另外,Mn摻雜起到了改善BST薄膜漏電流的作用。結果表明BST薄膜在摻雜濃度為2 mol%時介電性能相對較好。
[Abstract]:Ba1-xSrxTiO3BST thin films have high dielectric constant and excellent dielectric nonlinear effect. It has a good application prospect in dynamic random access memory (RAM) and voltage-adjustable microwave devices. In order to be compatible with semiconductor technology, BST thin films on Si substrates have become one of the current research hotspots. At present, the existence of this kind of BST thin films is mainly discussed. The problem is that the dielectric loss of the film is high. It is difficult to meet the requirements of application, but doping modification has become an important means to solve this problem. Firstly, Mn-doped Ba0.5Sr0.5TiO3 ceramics with different concentrations were prepared by solid-state reaction method, which were used as targets for preparing Ba0.5Sr0.5TiO3 thin films by pulsed laser deposition. Then the preparation process of BST/LNO/Si and the effect of mn doping on the properties of BST thin films were investigated on the Si Si 001) substrate. The main research results are as follows: firstly, Ba0.5Sr0.5TiO3 ceramics were prepared by solid state reaction. The effect of sintering temperature on the properties of ceramic targets was studied and the final sintering temperature was determined at 1300 鈩，

本文編號：1653174