BaxSr1-xTiO3前驱多层膜制备及后热处理条件的优化

用Ar 离子束多靶溅射沉积技术在单晶硅Si(100)上顺序沉积了TiO2、BaCO3、SrCO3叠层，并经后期低温扩散和高温晶化两步热处理过程制备了BaxSrl-xTiO3薄膜．用俄歇扫描电子能谱(AES)对其低温扩散效应(温度、时效、沉积顺序)进行了研究．实验结果表明：在低温段长时间保温或在中温段短时间保温都有利于各沉积组元充分扩散，扩散均匀的混合膜层经高温晶化(900℃)能形成多晶BaxSr1-xTiO3薄膜．     

溅射工艺参数对Ba0.5Sr0.5TiO3薄膜沉积速率和介电性能的影响

铁电/介电BST(BaxSr1-xTiO3)薄膜在微电子学、集成光学和光电子学等新技术领域有广泛的应用前景.用射频磁控溅射方法制备了厚约700 nm的Ba0.5Sr0.5TiO3薄膜,采用Al/BST/ITO结构研究了溅射功率、溅射气压、O2/(Ar O2)比和基片温度对上述BST薄膜沉积速率和介电性能的影响,并根据这些结果分析了较优的工艺条件,同时用XRD、XPS和SEM研究了薄膜的晶相、组成和显微结构.     

钛酸锶钡薄膜掺杂改性研究进展

钛酸锶钡(BaxSr1-xTiO3,BST)薄膜具有优良的铁电、介电性能,在可调谐微波器件、动态随机存储器、红外探测器阵列等方面具有良好的应用前景.综述了近年来BST薄膜掺杂改性研究所取得的进展,特别是对晶格掺杂和晶界掺杂进行了较详细的评述,并对目前BST薄膜掺杂研究的几个前沿问题进行了详细的讨论.     

BST铁电薄膜材料的研究现状及其进展

铁电钛酸锶钡(BaxSr1-x)TiO3是一种具有十分优越铁电/介电性能的材料,在可调微波器件及动态随机存储器件方面有很好的应用前景.介绍了钛酸锶钡薄膜材料的基本结构、制备技术、掺杂改性等方面的研究现状,并在性能改善的基础上,指出了该材料的未来发展方向.     

溶胶-凝胶法制备BaxSr1-xTiO3铁电薄膜的研究

介绍了sol-gel法制备BaxSr1-xTiO3铁电薄膜的工艺参数。在溶胶中加入一定体积百分含量的干燥化学控制添加剂（DCCA）可有效的防止薄膜开裂。通过IR、XRD谱图、C－V回线、I－V曲线等测试方法比较了金属醇盐法和以部分醋酸盐代替醇盐法制备薄膜的微观结构和性能。实验结果表明,全部采用醇盐为原料制备的BST薄膜性能较好。通过两种方法制备BST薄膜性能的差异,本文提出了这两种方法的成膜机理。     

非致冷红外焦平面阵列探测单元的制备

采用sol-gel方法制备出BaxSr1-xTiO3(BST)薄膜，并优化工艺提高其介温变化率最大可达6％。通过半导体光刻工艺，刻蚀出BST探测单元，较好的解决了UFPA技术中的探测单元制备问题。设计了初级信号处理电路，并用Protel进行了电路模拟，所得信号可以应用于进一步的信号处理。     

钛酸锶钡(BST)薄膜的介电性能研究

采用射频磁控溅射法制备了BaxSr1-xTiO2（简称BST）薄膜材料,研究了不同膜厚,晶粒尺寸的BST薄膜的介电系数温度特性（ε1-T),频率特性（ε-r-f),电压特性（εr-U)及损耗的温度特性（tgδ-T),频率特性（tgδ-f),找出了BST薄膜的非线性,损耗随尺度变化的规律。     

无纤维超微孔薄膜加工技术探讨与实践

无纤维超微孔薄膜（厚度为0．2～0．1mm、孔径小于0．3mm）是近几年出现的吸声材料。德国已成功地将无纤维超微孔薄膜应用在影剧院、体育馆的建筑声学工程中，国内由于加工问题没有解决，至今还没有将无纤维超微孔薄膜在声学工程中推广应用。通过对无纤维超微孔薄膜的加工工艺、方法的研究，提出了切实可行的加工工艺和方法并取得了成功。     

La0.5Sr0.5CoO3底电极上的BiNdFeO3薄膜的电性质。

用溶胶．凝胶方法在La0.5Sr0.5CoO3底电极上制备了纯的和10％A位Nd替代的BiFeO3薄膜。对薄膜的结构、形貌和电性质进行了研究。XRD研究表明两薄膜呈随机取向。而SEM测试结果表明，通过Nd替代，构成薄膜的晶粒显著减小，表面出现了针孔。铁电性研究表明，通过Nd替代，薄膜的铁电性得到显著增强，剩余极化强度由1．87μC/cm^2。增加到3．11μC/cm^2。而漏电流特性测试表明，Nd替代有效地限制了BiFeO3薄膜在正向偏压下的漏电流。     

平面可调谐微带天线的设计与仿真

铁电材料特别是锶钡钛酸盐（BaxSr1-xTiO3）这类强非线性介质的压电非线性特性^[1]应用到微带贴片天线的介质基片上，通过改变基片的等效介电系数B来实现微带天线的可调谐工作，对此方法进行了可行性研究。给出了理论验证性质的简单设计和仿真结果。     

BST/BZT/BST多层薄膜结构与性能研究

利用脉冲激光沉积法在LaNiO3/LaAlO3(001)基片上生长了Ba0.6Sr0.4TiO3(BST)和Ba(Zr0.2Ti0.8)O3(BZT)单层薄膜,以及Ba(Zr0.2Ti0.8)O3/Ba0.6Sr0.4TiO3/Ba(Zr0.2Ti0.8)O3(BZT/BST/BZT)多层薄膜.X射线衍射(XRD)分析发现,BST、BZT和LNO薄膜都具有高度的(00l)取向.原子力显微镜(AFM)显示三种样品表面光滑无裂纹,晶粒尺寸和表面粗糙度相当.电容测试表明,相对BST、BZT单层薄膜,多层薄膜具有最大的品质因数42.07.表明多层薄膜在微波应用中具有很大的潜力.     

Terahertz dielectric response of ferroelectric Ba(x)Sr(1-x)TiO3 thin films

Terahertz time-domain spectroscopy has been used to investigate the dielectric and optical properties of ferroelectric Ba(x)Sr(1-x)TiO(3) thin films for nominal x-values of 0.4, 0.6, and 0.8 in the frequency range of 0.3 to 2.5 THz. The ferroelectric thin films were deposited at approximately 700 nm thickness on [001] MgO substrate by pulsed laser deposition. The measured complex dielectric and optical constants were compared with the Cole-Cole relaxation model. The results show that the Cole-Cole relaxation model fits well with the data throughout the frequency range and the dielectric relaxation behavior of ferroelectric Ba(x)Sr(1-x)TiO(3) thin films varies with the films compositions. Among the compositions of Ba(x)Sr(1-x)TiO(3) films with different Ba/Sr ratios, Ba(0.6)Sr(0.4)TiO(3) has the highest dielectric constants and the shortest dielectric relaxation time.     

Dielectric properties of (Ba,Sr)TiO₃ thin films with varied microstructures prepared by the chemical solution deposition method for thin-film capacitors and ferroelectric varactors

We prepared epitaxially grown three-axis-oriented (Ba?.?S?.?)TiO? thin films on (100) platinum-coated (100) MgO single-crystal substrates by the chemical solution deposition method, using a solution derived from Ba(CH?COO)?, Sr(CH?COO)?, and Ti(O-i-C?H?)?. Microstructures of fabricated thin films depend strongly on the fabrication process, especially on the annealing condition. A (Ba,Sr)TiO? thin film fabricated with an annealing temperature of 1073K was found to be a single crystal by transmission electron microscopy. The single-crystal (Ba,Sr)TiO? thin film exhibited a (100) three-axis-orientation, which followed the (100) orientation of the platinum electrode on the MgO single-crystal substrate. A (100) three-axis-oriented (Ba,Sr)TiO? thin film may be useful for preparing a thin-film capacitor.     

Integration of coplanar (Ba,Sr)TiO/sub 3/ microwave phase shifters onto Si wafers TiO/sub 2/ buffer layers

In this paper, a Ba/sub 0.6/Sr/sub 0.4/TiO/sub 3/ (BST) tunable phase shifter with TiO/sub 2/ films as microwave buffer layer between BST and silicon (Si) substrates is presented. The TiO/sub 2/ buffer layer is grown by atomic layer deposition (ALD) onto Si substrate followed by pulsed laser deposition (PLD) of BST thin films onto the TiO/sub 2/ buffer layer. The phase shifter fabricated on BST films grown on TiO/sub 2//Si substrate shows a good figure of merit (FOM) of 75.4/spl deg//dB by exhibiting improved tunability while retaining an appropriate dielectric Q as compared to 55.1/spl deg//dB of BST/MgO structure. The TiO/sub 2/ buffer layer grown by ALD enables successful integration of BST-based microwave tunable devices with high resistive Si wafer.     

Integration of coplanar (Ba,Sr)TiO3 microwave phase shifters onto Si wafers using TiO2 buffer layers.

In this paper, a Ba0.6Sr0.4TiO3 (BST) tunable phase shifter with TiO2 films as microwave buffer layer between BST and silicon (Si) substrates is presented. The TiO2 buffer layer is grown by atomic layer deposition (ALD) onto Si substrate followed by pulsed laser deposition (PLD) of BST thin films onto the TiO2 buffer layer. The phase shifter fabricated on BST films grown on TiO2/Si substrate shows a good figure of merit (FOM) of 75.4 degrees/dB by exhibiting improved tunablity while retaining an appropriate dielectric Q as compared to 55.1 degrees/dB of BST/MgO structure. The TiO2 buffer layer grown by ALD enables successful integration of BST-based microwave tunable devices with high resistive Si wafer.     

Tunable capacitors employing BZN/BST thin films for RF applications

Tunable parallel-plate capacitors employing Bi(1.5)Zn(1.0)Nb(1.5)O(7)/Ba(0.5)Sr(0.5)TiO(3) (BZN/BST) thin films for RF applications are reported. The intermediate frequency measurements indicate that the BZN/BST-based varactors demonstrate large tunability of 39% at 40 V and high device quality factor of 300 at 1 MHz. The devices maintain quite low leakage current density even under a high applied bias. The quality factor analysis shows that the device quality factor is highly dependent on conductor loss of electrodes at frequencies above 1 MHz. The phase shifter employing BZN/BST-based varactors exhibits lower insertion loss than does employing semiconductor diodes at a designed frequency of 445 MHz, demonstrating the potential of tunable capacitors employing BZN/BST thin films for RF applications.     

Fabrication and characterization of epitaxial Ba0.7Sr0.3TiO3 thin films for optical waveguide applications

The optical properties of barium strontium titanate (Ba0.7Sr0.3TiO3; BST) thin films are described. The BST thin films were epitaxially grown upon MgO (001) substrates by pulsed laser deposition. The crystallographic properties of the BST thin films were examined by x-ray diffraction. The BST thin films were highly optically transparent in the visible region. The optical waveguide properties were characterized by a prism coupling technique. An inverse-WBK method was employed to determine the refractive-index profile along the thickness of the BST films. Optical losses were measured by a moving fiber method, and the optical losses were found to be 0.93 dB/cm for the TE0 mode and 1.29 dB/cm for the TM0 mode at 1550 nm. Electro-optic (E-O) properties were measured by a phase-modulation detection method at 632.8 nm, and the BST films exhibited a predominantly quadratic E-O effect with a quadratic E-O coefficient of 6.64 x 10(-18) m2/V2.     

Properties of the Barium–Strontium Titanate Films Deposited onto the Silicon Substrate by rf Cathode Sputtering

Technical Physics Letters - Using rf cathode sputtering of a target in the oxygen atmosphere, Ba0.6Sr0.4TiO3 solid solution thin films have been formed on the single-crystal Si(001) cut surface and...     

铅对(Pbx,Sr1-x)0.85Bi0.1TiO3薄膜结构与介电可调性影响的研究

用溶胶-凝胶法制备了（Pbx，Sr1-x）0．85Bi0．1TiO3薄膜，对其晶相结构、微观形貌和介电可调性进行了研究．结果表明，该薄膜以钙钛矿形式存在．快速热处理过程可分解得到高活性离子，直接形成比相应温度平衡状态析晶时更多的晶相量．这种晶相在一定条件下有分解和再结晶的趋势．随着Pb^2＋离子增加和Sr^2＋离子减少，钙钛矿相的四方相与立方相间的转变温度升高．薄膜处在铁电相和顺电相转变点附近时，可以获得较大的可调性．     

Improvement in dielectric and tunable properties of Fe-doped Ba0.6Sr0.4TiO3 thin films grown by pulsed-laser deposition

Fe-doped Ba(0.6)Sr(0.4)TiO3 (BST) thin films were prepared on Pt/Si substrates by the pulsed-laser deposition method. The concentrations of Fe dopants vary from 0.1 mol% to 1.0 mol%. Our results indicate that a certain amount of Fe dopants can decrease the dielectric loss of BST thin films without causing the significant reduction of the tunability. The leakage current of BST thin films also was reduced by the addition of Fe dopants. BST thin films doped with 0.3 mol% Fe ions show a minimum dielectric loss of 0.88% at 10(6) Hz, which is 1.7% for the undoped BST films. Moreover, the 0.3 mol% Fe-doped BST films reveal a maximum figure of merit (FOM) of 51, indicating the improved comprehensive dielectric and tunable properties.