非晶Ti-Al过渡层对Pt/Ba_(0.6)Sr_(0.4)TiO_3/Pt电容器结构和性能的影响  

Effect of Amorphous Ti-Al Buffer Layer on the Structure and Properties of Pt/Ba_(0.6)Sr_(0.4)TiO_3/Pt Capacitors

作　　者：赵冬月[1,2] 刘保亭[1] 郭哲[1] 李曼[1] 陈剑辉[1] 代鹏超[2] 韦梦祎 

机构地区：[1]河北大学物理科学与技术学院,保定071002 [2]河北大学电子信息工程学院,保定071002

出　　处：《人工晶体学报》2011年第1期161-165,共5页Journal of Synthetic Crystals

基　　金：国家自然科学基金(60876055;11074063);河北省自然科学基金(E2008000620);河北省应用基础研究计划重点基础研究项目(10963525D);高等学校博士点基金(20091301110002)

摘　　要：应用磁控溅射法在Pt/Ti/SiO2/Si(001)衬底上制备5 nm厚超薄非晶Ti-Al薄膜作为过渡层,利用脉冲激光沉积法制备Ba0.6Sr0.4TiO3薄膜,构造了Pt/Ba0.6Sr0.4TiO3/Pt(Pt/BST/Pt)和Pt/Ti-Al/Ba0.6Sr0.4TiO3/Ti-Al/Pt(Pt/Ti-Al/BST/Ti-Al/Pt)结构的电容器,研究了Ti-Al过渡层对Pt/BST/Pt电容器结构及其性能的影响。实验表明,过渡层的引入有效地阻止了Pt电极和BST薄膜的互扩散,降低了BST薄膜氧空位的浓度,提高了铁电电容器的介电性能。当测试频率为1 kHz、直流偏压为0 V时,介电常数由引入过渡层前的530增大到引入后的601,介电损耗则由0.09减小到0.03。而且过渡层的引入有效地降低了BST薄膜的漏电流,使正负向漏电流趋于对称,在测试电压为5 V时,漏电流密度由3.8×10-5A/cm2减小到8.25×10-6A/cm2。5 nm-thick amorphous Ti-Al buffer layer was deposited on Pt/Ti/SiO2/Si（001） substrate using magnetron sputtering to fabricate Pt/Ti-Al/Ba0.6Sr0.4TiO3（BST）/Ti-Al/Pt capacitor,in which BST film was prepared by pulsed laser deposition method.Moreover,a Pt/BST/Pt capacitor was also fabricated in order to study the impacts of the Ti-Al buffer layer on the structure and physical properties of the Pt/BST/Pt capacitor.The results indicated that the Ti-Al buffer layer could effectively prevent the interdiffusion between Pt electrode and BST film,lower the concentration of oxygen vacancy of the BST film,and improve the dielectric properties of the BST capacitors.The dielectric constant of the Pt/BST/Pt capacitor,measured at 1 kHz and zero-bias voltage,was increased from 530 to 601,and the dielectric loss was reduced from 0.09 to 0.03 by inserting the buffer layer to fabricate the Pt/Ti-Al/BST/Ti-Al/Pt capacitor.Furthermore,it is found that the Ti-Al buffer layer can lower the leakage current density of the BST capacitor and enable more symmetric current-voltage characteristics at positive and negative bias voltages.The leakage current density,measured at 5 V,was 8.25×10^-6 A/cm^2 for the BST capacitor with Ti-Al buffer layer,which is lower than 3.8×10^-5 A/cm^2 for the conventional Pt/BST/Pt capacitor.

关 键 词：BST薄膜 非晶Ti-Al薄膜 过渡层 脉冲激光沉积 

分 类 号：O484[理学—固体物理]