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铁电钛酸锶钡(BSTO)薄膜具备十分优越的铁电/介电性能,在可调谐微波器件和动态随机存储器(DRAM)方面显示出十分诱人的应用前景。而YBa2Cu3O7-δ(YBCO)高温超导薄膜作为其电极引入,明显降低了微波损耗,能够大大优化器件的性能。本文针对微波器件性能要求对比了各种常用基片的性能参数,描述了目前BSTO薄膜与BSTO/YBCO异质薄膜制备中存在的问题以及薄膜介电性能测试表征方法。利用脉冲激光沉积(PLD)技术成功制备出结构完整和质量较高的Ba0.5Sr0.5TiO3薄膜。同时,在1.2°斜切LaAlO3基片上研制有Ba0.1 Sr0.9TiO3/YBa2Cu3O7-δ异质双层膜,在1MHz频率、77K温度条件下,其介电常数为1200,介电损耗为0.0045,±30V直流偏压时可调性达到60％,在液氮温度下表现出良好的应用前景。
Barium strontium titanate (BSTO) ferroelectric thin film with very excellent ferroelectric / dielectric properties, tunable microwave devices and dynamic random access memory (DRAM) shows a very attractive prospect. The introduction of YBa2Cu3O7-δ (YBCO) high temperature superconducting thin film as its electrode significantly reduces the microwave loss and greatly optimizes the performance of the device. In this paper, performance parameters of various commonly used substrates are compared with performance requirements of microwave devices, and the problems existing in the preparation of heterogeneous thin films of BSTO and BSTO / YBCO as well as the method of testing and characterizing the dielectric properties of thin films are described. Ba0.5Sr0.5TiO3 thin films with high structural integrity and high quality were successfully prepared by pulsed laser deposition (PLD). At the same time, a Ba0.1 Sr0.9TiO3 / YBa2Cu3O7-δ heterogeneous bilayer membrane was developed on a 1.2 ° bevel LaAlO3 substrate with a dielectric constant of 1200 and a dielectric loss of 0.0045 at a frequency of 1 MHz and a temperature of 77K, ± 30V DC bias voltage can be adjusted up to 60%, showing good application prospects at liquid nitrogen temperature.