使用In_(2)Ga_(2)ZnO_(7)陶瓷靶材制备α-IGZO薄膜的光电性能研究

Optical and electrical properties of room temperature preparedα-IGZO thin films using an In_(2)Ga_(2)ZnO_(7) ceramic target

本文采用高纯度In_(2)Ga_(2)ZnO_(7)陶瓷靶材通过射频磁控溅射技术沉积铟镓锌氧化物(IGZO)薄膜。研究了IGZO薄膜的微观结构、生长状态、光学和电学性能。结果表明,在室温下制备的IGZO薄膜表面均匀且光滑。随着衬底温度的升高,薄膜的表面粗糙度逐渐增大。从室温升至300℃,所有制备的IGZO薄膜均是非晶态的,并具有良好的热稳定性。此外,可见光区域的透过率从91.93%下降到91.08%,光学带隙略有下降(3.79~3.76 eV)。通过原子力显微镜(AFM)和X射线光电子能谱(XPS)对不同温度下制备的IGZO薄膜的表征,可知在室温下制备的薄膜的表面粗糙度最小,并且氧空位含量最高。随着温度的升高,不均匀的颗粒分布,表面粗糙度的增加,以及氧空位的减少导致了α-IGZO薄膜的性能降低。综合分析可知,在室温下沉积的IGZO薄膜可以获得最佳的光学和电学性能,同时也预示了其在柔性衬底上的应用潜力。

In this study,a high-purity In_(2)Ga_(2)ZnO_(7) ceramic target was used to deposit indium gallium zinc oxide(IGZO)films by RF magnetron sputtering technology.The microstructure,growth state,optical and electrical properties of the IGZO films were studied.The results showed that the surface of the IGZO film was uniform and smooth at room temperature.As the substrate temperature increased,the surface roughness of the film gradually increased.From room temperature to 300℃,all the films maintained amorphous phase and good thermal stabilities.Moreover,the transmission in the visible region decreased from 91.93%to 91.08%,and the band gap slightly decreased from 3.79 to 3.76 eV.The characterization of the film via atomic force microscope(AFM)and X-ray photoelectron spectroscopy(XPS)demonstrated that the film prepared at room temperature exhibited the lowest surface roughness and the largest content of oxygen vacancies.With the rise in temperature,the non-homogeneous particle distribution,increase in the surface roughness,and reduction in the number of oxygen vacancies resulted in lower performance of theα-IGZO film.Comprehensive analysis showed that the best optical and electrical properties can be obtained by depositing IGZO films at room temperature,which indicates their potential applications in flexible substrates.