射频溅射法制备掺杂SnO_2纳米薄膜的研究

Study of Nanocrystalline Doped SnO_2 Thin Film Prepared by Reactive R. F. Sputtering

采用射频反应溅射法在氧化处理后的单晶硅基片上制备SnO2纳米薄膜,并在薄膜中掺杂Sb和Pd用于改变薄膜的气敏特性.运用X射线衍射(XRD)、扫描电镜(SEM)对薄膜的结构和表面形貌进行分析.结果表明,SnO2薄膜具有四方金红石结构,适量掺杂对SnO2薄膜结构无影响;薄膜晶粒粒径小于150nm,且粒径随退火温度的升高而增大.采用Debye Scherrer简化公式计算了薄膜晶粒粒径,分析了计算值与SEM观测值之间产生误差的原因.经700℃的温度退火后,掺原子比Pd为2%和Sb为2%的薄膜对酒精气体具有很高的灵敏度.

Tin oxide thin film have been deposited on oxided silicon substrates using a r.f. reactive sputtering process with a tin target in a mixed gas environment. Pd and Sb_2O_3 were light doped in thin films to enhance the sensibility. The resulting films have been characterized structurally using X-ray diffraction (XRD) and Scanning Electron Microscope (SEM). XRD has demonstrated that the tin oxide thin films have rutile SnO_2 structure and that the small range dopants did not change the crystallite structure. SEM has demonstrated that the dimensions of tin oxide crystallite were less than 150 nm. With the annealing temperature elevated the crystallites enlarged in dimensions. The average crystallite size was estimated with use of the Debye-Scherrer equation. The reasons that brought about the difference of crystallite size between estimated with the Debye-Scherrer equation and observed by SEM were discuss. After sintering at temperature of 700 ℃ the thin film doped with atomic 2% Pd and 2% Sb showed high sensitivity to alcohol vapor.