纯水基溶胶-凝胶法制备HfO2纳米超薄膜

摘要

微电子工业的发展提出了不断提高集成电路芯片上多种器件电容密度的迫切需求，因此开展厚度<10 nm超薄 HfO2高-k电介质薄膜的可控制备技术研究具有重要意义。以氯氧化铪、硝酸和双氧水为主要试剂配制了纯水基溶胶前驱体，使用去离子水对溶胶进行适当稀释后，采用旋涂法在经等离子体清洗的硅基片上制备 HfO2薄膜。以 XRR、AFM 以及XPS为主要手段对薄膜样品的厚度、表面形貌以及化学成分进行了分析，结果表明这种新颖的溶胶-凝胶技术可将薄膜的沉积速率控制在每旋涂周期1 nm以下，薄膜表面平整致密，成分符合化学计量比。%To meet the stringent demands of increasing capacitance density for various devices on microelectronic IC chips,it was necessary to develop new controllable techniques to deposit ultra-thin HfO2 high-k dielectric films with a thickness less than 10 nm.In this work,HfOCl2 ,HNO3 ,and H2 O2 were used as main raw mate-rials to prepare pure water-based solution precursor diluted with water.HfO2 films were produced via spin-coat-ing on silicon substrate cleaned with plasma.Film thickness,surface morphology and composition were investi-gated using X-ray reflectivity,AFM and XPS.The results show that this unique sol-gel approach enables con-venient preparation of smooth,dense,and stoichiometric HfO2 nano-films with a growth rate less than 1 nm/cycle.