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

本研究的主要目的是在微观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。在这一年里，我们重点研究了一种混合氧化物薄膜的沉积，并基于蒙特卡罗模拟分析了沉积机理。要研究的化学气相沉积系统是YSZ(氧化钇稳定氧化锆)化学气相沉积系统，它是以β-二酮基络合物，在这种情况下是Zr(DPM)_4和Y(DPM)_3为源材料。根据管式热壁CVD反应器内宏观生长速率沿轴向分布的理论结果和硅片上微尺度沟槽上沉积的薄膜形状，对沉积机理进行了模拟。并用实验结果对理论结果进行了评价。研究结果总结如下：(1)通过对沉积在微沟槽上的薄膜成分的实验观察，发现在该CVD系统中没有在气相中形成添加剂。(2)薄膜生长速率和薄膜成分的微观反应输运模型很好地解释了实验结果，该模型假定氧化锆和氧化钇的反应组分和单个生长速率的加和性是连续的气相和表面反应。

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.