SnO_2气敏薄膜的制作与性能研究

Preparation and Properties Study of SnO_2 Thin Films

采用射频溅射法制备了SnO2气敏薄膜,并在薄膜中掺杂Sb2O3和Pt用于气敏薄膜的增敏.使用XRD对制备的薄膜进行了结构分析,测量了薄膜的吸收光谱和电阻,并研究了薄膜工艺条件的改变对薄膜结构和性能的影响.结果表明,不同退火温度下处理的氧化锡薄膜均为金红石结构,退火温度对薄膜的晶粒尺寸和电阻有较大影响:退火温度愈高,薄膜中形成的晶粒越完整,晶化程度愈高;电阻率随着退火温度的升高而降低,考虑到气敏薄膜的敏感性能,本文选取1100℃为最佳退火温度.由于掺杂的影响,在氧化锡的禁带中产生了杂质能级,使薄膜对2722nm附近的红外光波产生了强烈吸收.

Tin oxide thin films have been deposited on oxidized silicon substrates using a r.f. reactive sputtering process with a tin oxide target in a pure argon gas environment. Pt and Sb_2O_3 were light doped in thin films to enhance the sensibility. Process parameters have been varied and the resulting films have been studied by X-ray diffractometer(XRD), spectrophotometer and ohmmeter. The result of XRD has demonstrated that the tin oxide thin films annealed at different temperature in atmosphere have rutile SnO_2 structures. The crystal dimensions and the resistance of the thin films were influenced by annealed temperature. Higher the temperature is, larger the dimensions is, and smaller the resistance is. Considering the sensibility, the films annealed at 1 100℃ are the best samples. Spectrophotometric analysis has demonstrated that the doped thin films absorbed drastically the 2 722 nm infrared rays due to the appearance of the impurity levels in the band gap.