摘 要使用脉冲激光沉积(pulsed laser deposition,PLD)技术,采用两种不同纯度(99.5%和99.99%)的ZnO靶材,在p型Si衬底上制备了两种ZnO/Si薄膜.原子力显微镜与X射线衍射分析表明,两种样品具有相似的显微形貌与相同的晶体结构.霍尔效应测试发现,两种ZnO/Si薄膜都展现出了低电阻率、高迁移率的电学性能,但是其导电类型完全相反.研究结果表明,衬底的性能对霍尔效应测试有巨大影响.利用二次离子质谱仪,发现了在低纯度的样品中存在着S杂质向Si衬底中扩散的现象,并直接导致了衬底的导电性能的反型.
The impact of Si substrates on the properties of ZnO film
ZHOU Jian\|QingZHOU Yong\|NingWU Zi\|JingLU QianWU Xiao\|Jing
(Department of Materials Science, Fudan University, Shanghai 200433, China)
AbstractNative ZnO films were fabricated by pulsed laser deposition with two different kinds of ZnO powder (99.5% and 99.99%). Atomic force microscopy was used to investigate the film morphology and toughness, and X\|ray diffractmetry for characterizing the crystal structures. The results indicated that the two samples had similar morphologies and the same crystal structure. By Hall effect measurements it was found that the two samples exhibited electrical properties of low resistivity and high Hall mobility but of opposite conduction type. Further analyses indicated that the Si substrates played a key role in the measurements of the electrical properties for both samples. A secondary ion mass spectrum measurement of the lower purity ZnO/Si sample showed that S diffused into the Si substrate near the interface, which led to the inversion of the substrate conduction type. ......