Micro-scale reaction analysis for multicomponent CVD and numerical study for initial stage of CVD film growth

本研究工作的主要目的是在微尺度上研究化学气相沉积的机理，并从理论和实验上阐明化学和物理因素对多组分化学气相沉积系统中薄膜成分的影响。在这一年中，我们专注于混合氧化物膜沉积，并分析了沉积机理的基础上蒙特-卡罗模拟。作为目标的CVD系统是使用β-二酮络合物（在这种情况下为Zr（NO3）_4和Y（NO3）_3）作为源材料的YSZ（氧化钇稳定的氧化锆）CVD。通过对管式热壁CVD反应器轴向沿着宏观尺度生长速率分布和硅片微沟槽上沉积膜形貌的理论分析，模拟了沉积机理。实验结果也验证了理论分析的正确性。研究结果总结如下。(1)通过对微沟槽上沉积的薄膜成分的实验观察数据，发现在该CVD系统中气相中没有形成添加物。(2)用微观反应输运模型很好地解释了薄膜生长速率和薄膜成分的实验结果，该模型假定了ZrO 2和YttO 2各自组分的气相反应和表面反应是连续的一级反应，且各组分的生长速率具有加和性。

The main purpose of this research work is to imvestigate the CVD mechanism in micro-scale and to clarify the effects of chemical and physical factors on film composition theoretically and experimentally in a multicomponent CVD ststem. In this year we focused on a mixed oxide film deposition, and analyzed the deposition mechanism based on a Monte-Carlo simulation. A CVD system to be targeted is YSZ (Yttria stabilized Zirconia) CVD using beta-diketonate complexes, Zr (DPM)_4 and Y (DPM)_3 in this case, as source materials. The deposition mechanism was simulated by theoretical results of macro-scale growth rate distribution along the axis of tubular hot wall CVD reactor and the film shape deposited on a micro-scale trench graved on a silicon chip. The theoretical results were also evaluated by the experimental results. The research results were summarized as follows.(1) Through the data of experimentally observed composition in the film deposited on a micro trench, it was found that no addacts were formed in the gas phase in this CVD system.(2) The experimental results of film growth rate and film composition were well explained by a micro reactive-transport model which assumes consecutive first order gas-phase and surface reactions for respecitive component and additivity of individual growth rates of Zirconia and Yttria.