PLT15薄膜热释电红外传感器的研制

Preparation and Investigation of the Pyroelectric Infrared Sensors Made of PLT15 Thin Films

用射频磁控溅射法在Ｐｔ／Ｔｉ／ＳｉＯ２／Ｓｉ（１００）结构衬底上沉积了高度Ｃ轴取向Ｌａ改性的ＰｂＴｉＯ３（ＰＬＴ１５）薄膜．研究了ＰＬＴ１５薄膜的电晕极化方法，用此方法同时对多个热释电敏感单元进行了极化．利用ＰＬＴ１５薄膜制备了热释电红外传感器，薄膜厚度是２μｍ，真空蒸发的Ｎｉ－Ｃｒ电极面积为１．２ｍｍ×１．０ｍｍ，敏感元下的Ｓｉ（１００）基片用热ＫＯＨ和ＥＰＷ进行刻蚀．用所设计的热释电系数测试系统对ＰＬＴ１５薄膜样品进行了测试，研究了其热释电特性．测试结果表明，ＰＬＴ１５薄膜样品的热释电电流ｉｐ平均为２．１×１０－１１Ａ，而对应的热释电系数ｐ为２．５２×１０－８Ｃ·（ｃｍ２·Ｋ）－１．

C axis mostly oriented and La modified PbTiO 3 (PLT15) thin films are deposited on the substrate with Pt/Ti/SiO 2/Si(100) structure by rf magnetron sputtering. Corona poling is investigated on the PLT15 thin films and a number of pyroelectric sensing cells of the PLT15 thin films are polarized by the use of corona poling method at the same time. Pyroelectric infrared (IR) sensors are fabricated by using the PLT15 films, the thickness of the films is 2 μm, the area of Ni Cr electrode evaporated by vacuum is 1.2 mm×1.0 mm, and the Si (100) substrate under sensing cell area is etched off by heated KOH and EPW. The samples of the PLT15 thin films have been measured. The results have shown that i p aver is 2.1 ×10 -11 A and p is 2.52×10 -8 C·(cm 2·K) -1 for the samples of the thin films. The thin films are the most suitable materials for IR sensors.