Al掺杂ZnO薄膜的射频磁控溅射工艺与光电性能研究

RF Magnetron Sputtering Process and Photoelectric Property of Al Doped ZnO Films

用射频磁控溅射法制备Al掺杂ZnO(ZAO)薄膜,研究溅射与真空退火工艺对ZAO薄膜的显微结构及光电性能的影响。采用X射线衍射(XRD)对ZAO薄膜的显微结构进行了测试分析,用四探针测试仪、紫外-可见分光光度计对ZAO薄膜的光电性能进行了测试分析。结果表明:随溅射时间的增加,样品由非晶态向晶态转变,同时也出现(002)择优取向强弱的变化。退火提高了溅射时间较长的薄膜的结晶质量。溅射时间的增加使溅射态ZAO薄膜的光学带隙变窄,但退火处理则使光学禁带宽度增大。溅射时间的增加以及退火处理均使薄膜的透光率稍有下降,但所有ZAO薄膜的透光率均在90%以上。薄膜的电阻率随溅射时间的增加先降低,后稍有回升。退火使薄膜的电阻率显著降低,当溅射时间为60min时退火后薄膜的电阻率达到最低值,为9.4×10-4Ω.cm,其方块电阻低至18.80Ω/□。

Al-doped ZnO （ZAO） films were prepared on glass substrates at room temperature by RF magnetron sputtering. The microstructures of ZAO films were investigated with X-ray diffraction （XRD） and its optical and electrical properties were respectively measured using a four-point probe technique and UV-756 spectrophotometer at the room temperature. With increasing the sputtering time, the structure of ZAO films changes from non crystalline structure to crystalline structure, and at the same time the intensity of （002） peak changes, and the optical band gap of ZAO films reduces. But the optical band gap of the ZAO films increases after vacuum annealed at 400℃ for 2 h. The in creasing of sputtering time and the annealing treatment make the transmittance of ZAO films reduce, but the transmittance of ZAO films is all higher than 90%. With increasing of sputtering time, the resistivity of films first reduces, and then increases slightly. The annealing treatment make the resistivity of ZAO films reduces evidently, and the ZAO film sample annealed for 2 h of sputtering time gains the lowest resistivity, 9.4×10^-4Ω·cm, and the lowest square resistance, 18.80Ω/□.