溶胶凝胶钽酸锂薄膜热释电红外探测器的设计与制备(英文)

Design and fabrication of pyroelectric infrared detector based on sol-gel derived LiTaO_3 thin film

在带微桥结构的石英玻璃基底上设计了一种新型Al-LiTaO3-ITO红外探测结构。在响应／参考双单元结构框架下，由振动、环境温度变化和日照变化引起的无效信号输出在前置放大电路处被消除掉了。用醋酸锂和乙醇钽作为起始反应物，通过溶胶凝胶工艺生成了对红外敏感的钽酸锂薄膜，并详细讨论了基于钽酸锂薄膜的红外探测器件制备工艺。用ITO衬底作下电极，蒸镀的Al点作上电极，在室温条件下测试了薄膜的介电特性，在1kHz处，介电常数为53．28，在40～10kHz内，介电损耗和介电系数呈下降趋势。器件的电压响应和比探测率测试结果表明75Hz处得到响应电压峰值9685V／W，器件的比探测率在70-100Hz区域保持在6．12×10^8cmHz^1／2 W^-1附近。

A new Al-LiTaO3-ITO infrared detecting structure on quartz glass substrate with a micro bridge is designed. Under the response/reference dual-element configuration, undesirable signals, caused by vibration, ambient temperature change and sunlight, are cancelled out at the input of the preamplifier circuit. The LiTaO3 thin film was chosen as infrared sensing film and prepared by a sol-gel process using lithium acetate and tantalum ethoxide as starting materials. The fabrication process of device is discussed in details. The dielectric properties of the sol-gel prepared LiTaO3 thin film were measured using evaporated AI dots as front electrode and the ITO substrate as bottom electrode. The dielectric coefficient of LiTaO3 thin film is about 53.28 at 1 kHz. The dielectric coefficient and the dielectric loss appear falling tendency within the measured frequency range from 40 Hz to 10K Hz. Voltage response experimental results of the LiTaO3 device is obtained by an infrared device measurement system and indicate that the response voltage peak is about 9685V/W at 75Hz, and the specific detectivity D^＊ peak of the device is near 6.12 × 10^8cmHz^1/2 W^-1 from 70Hz to 100Hz.