ALD沉积HfO2薄膜生长行为及其调控

Growth Behavior of Hafnium Oxide Film by Atomic Layer Deposition and Its Modulation

摘要:

采用原子层沉积（ALD）的方法，选择四二乙基氨基铪（TDEAH）和水作为反应前驱体，在p型(100)单晶硅衬底上制备了HfO2高介电质薄膜。系统研究了前驱体流量、反应气压、反应温度等工艺参数对HfO2薄膜生长质量的影响。通过工艺调控，发现存在两种薄膜生长模式：类CVD（化学气相沉积）生长模式和ALD生长模式。发现薄膜的生长模式主要依赖于制备工艺参量：脉冲参量M和冲洗参量Q，通过优化工艺参数，可实现薄膜生长由类CVD生长模式向ALD生长模式的转变，并获得了0.1 nm/周次的最优薄膜生长速率。同时，薄膜微结构与表面形貌的表征结果表明：薄膜的非晶晶态转变受温度和膜厚两个因素共同控制。

Abstract:

High-k hafnium oxide films were deposited by atomic layer deposition (ALD) on p-type Si (100) substrates. Tetrakis-diethylamino-hafnium (TDEAH) and water were used as hafnium precursor and the oxidant, respectively. Effects of deposition parameters, e.g., flow of precursors, pressure of the reactor, and temperature of the reactor and precursors on the growth of HfO2 films were investigated. By the adjustment of deposition parameters, two growth models of HfO2 films, chemical vapour deposition (CVD) liked growth model and ALD growth model were found. Results indicate that the growth model mainly depends on Q and M. There exists a transition from CVD-liked growth model to ALD growth model by the optimization of deposition parameters. The optimal deposition parameters with a GPC (growth per cycle) of 0.1 nm /cycle were obtained. Moreover, the results show that the crystallization of HfO2 film is under the control of temperature and thickness of the film.