磁控反应溅射SnO_2薄膜的气敏特性研究

Study on Gas Sensing Property of SnO_2 Thin Film Prepared by Magnetic Reactive Sputtering

为研究SnO2薄膜的气敏特性,采用直流磁控反应溅射法制备了SnO2薄膜.探讨和分析了SnO2薄膜气敏元件的敏感机理.对SnO2薄膜的电阻和灵敏度的测试以及对实验结果的分析表明:SnO2薄膜厚度在150～400 nm为宜,一般膜厚在250 nm时较为敏感.在SnO2薄膜中掺入Pd、Pt、Ag等微量杂质可大大提高SnO2薄膜气敏元件的灵敏度,且使灵敏度的峰值向低温方向移动,增强了对H2、CO和C2H5OH等可燃气体的选择性、响应时间由3 min缩短到0.5s以下.

Studied were the gas sensing properties of SnO2 thin film prepared by magnetic reactive sputtering. The sensing mechanism for gas sensor of SnO2 thin film was also discussed. Measuring results (resistance and sensitivity) indicate that of SnO2 thin film, suitable thickness is 150~400 nm, optimal thickness 250 nm. The sensitivity of SnO2 thin film sensor and the selectivity about H2, CO and C2H5OH will increase by doping microamount impurities such as Pd, Pt and Ag. The response time is also reduced less than 0.5 s.