射频磁控反应溅射制备HfO_2薄膜的工艺及电性能

Influence of Technical Parameters on Electrical Properties of Hafnium Oxide Thin Film Prepared by RF Magnetron Sputtering

采用射频磁控反应溅射法,以高纯Hf为靶材、高纯O2为反应气体,成功地在p型硅衬底上制备了高k栅介质HfO2薄膜,并对薄膜的沉积速率、成分和电学性能进行了研究。结果表明,薄膜沉积速率随射频功率增加而增大,随O2气流量增加而减小,随溅射气压增加呈先增大后减小的趋势。制备的薄膜中Hf和O元素的原子浓度比基本符合化学计量比。研究了薄膜的C-V特性;获得了O2流量、射频功率及退火温度对薄膜电学性能的影响规律。

Hafnium oxide thin films are successfully prepared by RF magnetron reactive sputtering on ptype Si for high-k gate dielectric with hafnium as the target. The deposition rate, composition and C-V characteristic have been investigated. The results show that the deposition rate increases with increasing power~ decreases with increasing Oz flow rate; firstly increases and then decreases with increasing sputtering pressure. Hafnium and oxygen atoms in the films form HfOz. The ratio of Hf/O is close to 1：2, indicating a good stoichiometry. The low leakage current is achieved after annealing. From the C-V curves, the dielectric constant and the fixed charge density are calculated. The influence of the oxygen flow, power and annealing temperature on the electrical properties of the film has also been investigated. The obtained set of data shows that the films with the best electrical performances are produced at low deposition rate.