PEALD HfO_2栅介质薄膜的界面优化及其特性表征  

Interface Optimization and Characterization of PEALD HfO_2 Gate Dielectric Film

作　　者：徐大伟[1,2] 程新红[1] 曹铎[1,2] 郑理[1,2] 万文艳[1,2] 俞跃辉[1] 

机构地区：[1]中国科学院上海微系统与信息技术研究所信息功能材料国家重点实验室,上海200050 [2]中国科学院大学,北京100049

出　　处：《半导体技术》2013年第10期755-759,共5页Semiconductor Technology

基　　金：国家重大研究计划资助的课题(2009ZX02039-006);国家自然科学基金资助项目(11175229)

摘　　要：采用等离子体增强原子层沉积技术在Si衬底上制备了HfO2栅介质薄膜。为了抑制HfO2薄膜与Si衬底间界面层的生长,首先对Si衬底进行了原位的氧等离子体和氨等离子体预处理,高分辨透射电子显微镜被用来表征HfO2薄膜和界面层的厚度及形态。当氧等离子体和氨等离子体的功率分别为75 W和150 W时,界面层的生长得到了有效控制,厚度为0.83 nm,X射线光电子能谱分析表明该界面层主要由具有较高介电常数的HfSiON组成。MIS电容被用来研究HfO2薄膜的电学特性,当HfO2薄膜物理厚度为3 nm时,等效栅氧厚度为1.04 nm,电容回滞大小为35.8 mV。漏电特性曲线显示,在距离平带电压为1 V的位置处,漏电流密度仅为0.64!A/cm2。HfO2 gate dielectric film was fabricated on Si substrate by using plasma enhanced atomic layer deposition （PEALD）. In order to inhibit the growth of interfacial layer between HfO2 and Si substrate, in-situ oxygen and ammonia plasma pre-treatment to Si substrate were processed firstly. High- resolution transmission electron microscopy was used to characterize the thickness and morphology of interfacial layer and HfO2 thin film. The growth of interfacial layer was effectively controlled when the power of oxygen and ammonia plasma were 75 W and 150 W, respectively, and the interfacial layer was 0. 83 nm. The interface layer was mainly composed of HfSiON with high dielectric constant by X-ray photoelectron spectroscopy. MIS capacitor was fabricated to examine the electrical property of HfO2 thin film. When the thickness of HfO2 film was 3 nm, an equivalent oxide thickness of total gate dielectric stacks of l. 04 nm was obtained and the hysteresis was estimated to be 35.8 mV. The leakage current density of 0.64 μA/cm2 was observed from the leakage characteristic curves where the gate bias was 1 V beyond the flat band voltage.

关 键 词：等离子体预处理 等离子体增强原子层沉积（PEALD） 氧化铪 高介电常数材 料 界面优化 

分 类 号：TN304[电子电信—物理电子学] TN305.2