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LIU Gui-jun HU Wen-cheng SHEN Yi-dong 《中国电子科技》2007,5(1):47-49,90
Ferroelectric Ba0.65Sr0.35TiO3 (BST) thin films on the Pt/Ti/SiO2/Si substrate have been successfully prepared by sol-gel. Such films have approximately 300 nm thicknesses with a remnant polarization of about 2.95 μ℃/cm^2 and a coercive field of about 21.5 kV/cm. The investigations of X-ray diffraction and atomic force microscopy show that the BST films annealed at 650 ℃ exhibit a tetragonal structure and that the films dominantly consist of large column or grains of about 89 nm in diameter. The curves of the temperature dependence of dielectric coefficient in different frequencies display the curie transition at the temperature around 23 ℃. The dielectric loss tangent of BST thin fdms at 100 kHz is less than 0.04. As a result, the BST thin films are more applicable for fabrication of infrared detector compared with the BST thin films reported previously. 相似文献
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Ferroelectric Ba0.65Sr0.35TiO3 (BST) thin films on the Pt/Ti/SiO2/Si substrate have been successfully prepared by sol-gel. Such films have approximately 300 nm thicknesses with a remnant polarization of about 2.95 C/cm2 and a coercive field of about 21.5 kV/cm. The investigations of X-ray diffraction and atomic force microscopy show that the BST films annealed at 650 ℃ exhibit a tetragonal structure and that the films dominantly consist of large column or grains of about 89 nm in diameter. The curves of the temperature dependence of dielectric coefficient in different frequencies display the curie transition at the temperature around 23 ℃. The dielectric loss tangent of BST thin films at 100 kHz is less than 0.04. As a result, the BST thin films are more applicable for fabrication of infrared detector compared with the BST thin films reported previously. 相似文献
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溶胶-凝胶法制备掺镧钛酸铅铁电薄膜的研究 总被引:1,自引:0,他引:1
采用溶胶-凝胶法在Pt/Ti/SiO2/Si衬底上制备了La掺杂的PbTiO3铁电薄膜(PLT),X-射线衍射测量表明PLT薄膜呈高度(100)择优取向,原子力显微镜和扫描电子显微镜测量表明制备的PLT薄膜的表面平整、结构致密。RT66A测量表明PLT薄膜有优良的铁电特性,500kV/cm的外加电场下,剩余极化为10.6μC/cm^2,矫顽电场为55kV/cm。用HP4194A分析了薄膜的介电特性。100kHz时的介电常数为652。 相似文献
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BST薄膜的Sol-Gel法制备及其电学性能的研究 总被引:3,自引:0,他引:3
应用溶胶-凝胶(Sol-Gel)工艺制备了组分为r(Ba:Sr)=0.65:0.35的BST薄膜,研究了BST薄膜的显微结构、介电特性和漏电流特性,实验结果表明:BST薄膜经650℃热处理后,巳形成完整的立方钙钛矿结构,薄膜经900℃热处理后,其表面光滑、致密、无裂纹、无针孔,圆球形的小颗粒均匀分布。当偏置电压为0时,BST薄膜的介电常数和损耗因子分别为542和0.035。漏电流特性分析结果表明:采用RuO2作为底电极,在1.5V的偏压下BST薄膜的漏电流密度为0.52μA/Cm^2,该值比Pt/RuO2混合底电极上制备的BST薄膜的漏电流密度(72nA/cm^2)大1个数量级,因此,Pt/RuO2混合底电极既克服了RuO2底电极漏电流大的缺点,又解决了Pt底电极难以刻蚀的困难,是制备大规模动态随机存取存储器的电容器列阵的最低底电极材料。 相似文献
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采用射频磁控溅射法在Si和Pt/TiOx/SiO2/Si衬底上沉积了(Ba0.65Sr0.35)TiO3铁电薄膜,研究了BST铁电薄膜微观结构和介电性能。实验结果表明:衬底温度在550℃,工作气压为2.0 Pa的溅射条件下沉积的BST薄膜,经750℃退火处理30 min后,形成了完整的钙钛矿相;与Si衬底相比,在Pt衬底上制备的BST薄膜晶粒更均匀、表面平整无裂纹。在室温、频率为100 kHz条件下薄膜的介电常数ε=353.8,介电损耗tanδ=0.012 8。介电温谱结果表明制备的(Ba0.65Sr0.35)TiO3铁电薄膜居里温度在5.0℃左右。 相似文献
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用脉冲激光沉积工艺制备Ba0.5Sr0.5TiO3(简称BST)薄膜和Ba0.5Sr0.5TiO3/LaNiO3(简称BST/LNO)薄膜。在650℃原位退火10 min,获得了(100)和(110)择优取向生长的BST和BST/LNO薄膜,薄膜晶粒呈柱状结构,BST薄膜和BST/LNO异质结构薄膜的晶粒尺寸分别为150~200 nm和50~80 nm。在室温和1 MHz条件下,BST薄膜和BST/LNO异质结构薄膜的相对介电常数和介电调谐率分别达811和58.9%、986和60.1%;用LNO作底电极,可增益介电常数和介电调谐率。 相似文献
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退火工艺对钛酸锶钡薄膜结构的影响 总被引:4,自引:0,他引:4
采用射频磁控溅射在Pt/Ti/SiO2/Si(100)衬底上制备Ba0.6Sr0.4TiO3(BST)铁电薄膜,在500~750℃之间对薄膜快速退火。XRD分析表明:500℃时BST薄膜开始晶化为ABO3型钙钛矿结构,温度越高结晶越完整,晶粒越大。理论计算表明,薄膜在低温退火后无择优取向,高温退火后在(111)、(210)晶面有择优取向。退火气氛、保温时间、循环次数等因素对薄膜晶粒大小无明显影响,但对表面粗糙度和结晶程度影响较大。 相似文献
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用R.F.磁控溅射法在p—Si(100)衬底上沉积Ba0.5Sr0.5TiO3/RuO2异质结,BST薄膜的晶相和表面形貌用XRD和SEM分析,表明在衬底温度为550℃时,薄膜的结晶度高、表面粗糙、晶粒较大.电容器InGa/BST/RuO2的介电特性由ε-V特性和I—V特性描述.薄膜在零偏压下ε=230、tgδ≈0.03.低电场条件下,薄膜的漏电流随电压呈饱和特性,属电子跳跃传导,且通过改善薄膜的结晶度可减小该漏电流.高电场条件下,漏电流符合肖特基发射规律. 相似文献
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Epitaxial Ba0.6Sr0.4TiO3 (BST) thin films were deposited on LaAlO3 (LAO) substrates with the conductive metallic oxide La0.5Sr0.5CoO3 (LSCO) film as a bottom electrode by pulsed laser deposition (PLD). Xray relationship of BST/LSCO/LAO was [001] BST//[001]LSCO//[001] LAO. The atomic force microscope (AFM)revealed a smooth and crackfree surface of BST films on LSCOcoated LAO substrate with the average grain size of 120 nm and the RMS of 1.564 nm for BST films.Pt/BST/LSCO capacitor was fabricated to perform CapacitanceVoltage measurement indicating good insulating characteristics. For epitaxial BST film, the dielectric constant and dielectric loss were determined as 471 and 0.03, respectively. The tunabilty was 79.59% and the leakage current was 2.63×107 A/crm2 under an applied filed of 200 kV/cm. Furthermore, it was found that epitaxial BST (60/40) films demonstrate wellbehaved ferroelectric properties with the remnate polarization of 6.085 μC/cm2 and the coercive field of 72 kV/cm. The different electric properties from bulk BST (60/40)materials with intrinsic paraelectric characteristic are attributed to the interface effects. 相似文献
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在传统的丝网印刷厚膜制备工艺中增加了两步加压预处理流程,采用这种新方法制备了致密的Ba0.6Sr0.4TiO3(BST)厚膜,并系统地研究了两步加压法对BST厚膜微结构和介电性能的影响。结果表明,与传统工艺相比,两步加压法可使BST厚膜获得更致密的微结构和更高的介电调谐率。在20℃和10kHz环境下,厚膜的介电常数和介电损耗分别为958和0.013 4,6kV/mm偏场下介电调谐率和优值分别为48.6%和36.3。 相似文献
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采用溶胶-凝胶法在Si(111)和Pt/Ti/SiO2/Si衬底上制备Ba4Nd9.33Ti18O54(BNT)介质薄膜,采用X线衍射仪(XRD)和扫描电子显微镜(SEM)研究了不同退火温度对薄膜结构和表面形貌的影响。结果表明当薄膜在950℃下退火2h后具有较好结晶质量的钨青铜结构,所得到的薄膜表面较为疏松;通过掺入质量分数为2%B2O3-2SiO2,可进一步将BNT薄膜的晶化温度降至900℃,且结构致密。介电性能测试表明,1 MHz频率下BNST薄膜的介电常数为45,介电损耗为1.1%,30V偏压下漏电流密度为4.13×10-6 A/cm2。 相似文献
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激光热冲击引起PZT压电薄膜铁电性能的变化 总被引:4,自引:2,他引:2
应用高能量单脉冲激光作用在锆钛酸铅 (PZT)压电薄膜上 ,研究脉冲激光的热冲击对PZT薄膜性能产生的影响。发现在激光未烧熔薄膜的能量密度下 ,经过激光作用后 ,PZT薄膜的铁电性能发生变化 :在外加电压为 6V时 ,剩余极化强度值Pr 从 32 6 99μC/cm2 变到 2 6 316 μC/cm2 ;矫顽电场保持为 38 396kV/cm不变 ;疲劳性能变稳定 ,在循环 1 75× 10 9次时 Pr 衰变率由 4 4 3%变为 34 7%。最后讨论分析了产生这种现象的微观机理。 相似文献
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高度(100)取向的BST薄膜及其高介电调谐率 总被引:2,自引:0,他引:2
用脉冲激光沉积法制备(Ba1-xSrx)TiO3(x=0.35,0.50简称BST35和BST50)介电薄膜。在650℃原位退火10min,获得高度(100)取向柱状生长的晶粒。BST35薄膜的平均晶粒尺寸为50nm,BST50薄膜的晶粒尺寸为150~200nm。在室温和1MHz条件下,BST35的最大εr和调谐率分别达到810和76%,其介电调谐率高于国内外同类文献报道的数据;BST50的εr和调谐率最大分别达到875和63%。薄膜为(100)取向生长,因为薄膜沿平面c轴极化而产生应力,在电场作用下,而获得高介电调谐率。 相似文献