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用CeO2陶瓷靶材,使用脉冲激光沉积(PLD)技术在Si(100)衬底上制备了CeO2薄膜。研究了衬底温度、沉积氧压对薄膜性能的影响,实验制备出了高度(111)取向的CeO2薄膜。使用X射线衍射(XRD)、反射式高能电子衍射(RHEED)对薄膜进行晶体结构的表征。结果表明:随着衬底温度的增加,薄膜中的残余宏观应力(拉应力)及微观应力逐渐减小,薄膜结晶质量不断提高,而沉积氧压对此影响较小。RHEED图像显示使用PLD方法在Si衬底上沉积的薄膜具备较高的结晶性及原子级平整的表面。使用原子力显微镜(AFM)对样品进行表面粗糙度分析,发现不同温度下生长的薄膜均具有光滑的表面,方均根粗糙度(RMS)均在0.4 nm以下。使用Keithley4200半导体测试仪、椭偏仪对薄膜进行电性能及光学性能分析,发现衬底温度对薄膜的电学性能有显著影响,并且CeO2薄膜结晶状态与电学性能有直接的联系。
CeO2 films were prepared on Si (100) substrates using CeO2 ceramic targets using pulsed laser deposition (PLD). The effects of substrate temperature and oxygen deposition pressure on the properties of the films were investigated. CeO2 films with high (111) orientation were prepared. The crystal structure of the films was characterized by X-ray diffraction (XRD) and reflection-type high energy electron diffraction (RHEED). The results show that with the increase of substrate temperature, the residual macroscopic stress (tensile stress) and the micro-stress in the film decrease gradually, the crystalline quality of the film increases continuously, but the deposition oxygen pressure has little effect on the film. RHEED images show that films deposited on Si substrates using PLD methods have higher crystallinity and atomically flat surfaces. The surface roughness of the samples was analyzed by atomic force microscope (AFM). The films grown at different temperatures showed a smooth surface and the root mean square roughness (RMS) was below 0.4 nm. The electrical and optical properties of the films were analyzed by Keithley4200 semiconductor tester and ellipsometer. The results showed that the substrate temperature had a significant effect on the electrical properties of the films, and the crystalline state and electrical properties of CeO2 films were directly related.