Fabrication and characterisation of barium strontium titanate thick film device structures for microwave applications
Fabrication and characterisation of barium strontium titanate thick film device structures for microwave applications
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DOI：
10.1016/j.jeurceramsoc.2006.05.051
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发表时间：
2007
影响因子：
5.7
通讯作者：
Dou Zhang;Wenfei Hu;C. Meggs;B. Su;T. Price;D. Iddles;M. Lancaster;T. Button
中科院分区：
文献类型：
--
作者：
Dou Zhang;Wenfei Hu;C. Meggs;B. Su;T. Price;D. Iddles;M. Lancaster;T. Button
采用丝网印刷法在氧化铝衬底上制备了钛酸锶钡（BST）薄膜，并研制了微波移相器用可调谐电容器元件。选择Ba0.70Sr0.30TiO3组合物用于初始器件，因为它已被证明在室温下具有高的可调谐性。一个垂直电容器测试结构，包括Pt下电极，BST膜和Ag上电极已被用于整个工作。在2-3GHz的可调谐性和品质因数（相移/插入损耗dB）被发现是强烈依赖于BST层的烧结温度，随着烧结温度的升高，性能得到改善。然而，对于>1280°C的烧结温度，无法测量器件特性，这可能表明下部Pt电极存在问题。为了降低致密化所需的烧结温度，还使用添加了烧结助剂的其他BST组合物制造了测试结构。最后，给出了基于电容测试结构和优化工艺条件的反射式移相器（RTPS）的微波测试结果。
Tunable capacitor elements for microwave phase shifter applications have been fabricated by screen printing barium strontium titanate (BST) films on alumina substrates. A Ba0.70Sr0.30TiO3composition was chosen for the initial devices as it has been shown to exhibit high tunability at room temperature. A vertical capacitor test structure involving a Pt lower electrode, BST film and Ag top electrode has been used throughout the work. The tunability and figure of merit (phase shift/dB of insertion loss) at 2–3GHz were found to be strongly dependent on the sintering temperature of the BST layers, with properties improving as the sintering temperature was increased. However, for sintering temperatures >1280°C, the device properties could not be measured, possibly indicating a problem with the lower Pt electrodes. In order to reduce the sintering temperature required for densification, test structures have also been fabricated using other BST compositions to which sintering aids have been added. Finally, a reflection-type phase shifter (RTPS) based on the capacitor test structure and optimised processing conditions is presented with microwave measurements results.