退火气氛对ZnO薄膜晶体管电学稳定性的影响

Effect of rapid annealing gas atmosphere on hysteretic stability of ZnO thin film transistors

在低温条件下(90℃)使用射频磁控溅射在表面长有100 nm厚的氧化硅绝缘层的硅衬底上沉积ZnO薄膜,并制备成薄膜晶体管器件,然后放入不同气氛下进行退火.研究不同的退火气氛对ZnO薄膜晶体管(TFT)的电学性能的影响,并对ZnO薄膜进行了X射线衍射(XRD)测试和光致发光(PL)测试,使用场发射扫描电子显微镜(SEM)和原子力显微镜(AFM)观察ZnO薄膜的表面形貌.实验结果表明,不同的退火气氛对ZnO薄膜晶体管的性能有着显著的影响,在N2氛围下进行退火的器件性能最优,电流开关比达到了5.88×107,滞回稳定性ΔVTH仅为0.2 V,界面态密度DIT为3.34×1012cm-2eV-1.

ZnO thin films were deposited on silicon substrate by radio frequency magnetron sputtering at low temperature(90 ℃).Thin film transistors were fabricated,and then annealed in different atmospheres.The effects of different rapid annealing atmosphere on the electrical properties of ZnO thin film transistors were studied.X-ray diffraction(XRD) and photoluminescence(PL) measurements were carried out on ZnO thin films.The surface morphology of ZnO thin films was observed by field emission scanning electron microscopy(SEM) and atomic force microscopy(AFM).The experimental results show that different rapid annealing atmosphere has significant influence on the performance of ZnO thin film transistors.The device annealed in N2 atmosphere has the best performance.The Ion/Ioff is 5.88×107,and the hysteretic stability ΔVTH is only 0.2 V.The density of interface state DIT is 3.34×1012cm-2eV-1.