Gas phase kinetics of CVD precursors

有机金属化合物，如二茂铁或乙酰丙酮铝，用于从气相中生产薄膜和颗粒。在很大程度上，对气相中的反应动力学研究得不到很好，这使得合理的工艺规划变得困难甚至不可能。在第一个项目阶段，研究了三种典型和重要的CVD前体在气相中的热分解。借助于最新的同步加速器质谱学方法(I2PEPICO)，可以更好地确定惰性气体中转化的反应机理，并确定第一动力学参数。这些研究是在流动反应器中进行的，使用流体力学模拟对其进行了优化；还使用CFD模拟确定了微反应器的温度场和停留时间。在本申请的延续期内，所调查的化学气相沉积前体与其他反应伙伴，如水蒸气、乙烯或氢的反应是人们感兴趣的重点，因为这些反应经常用于气相合成过程。这些反应的动力学参数和反应级数将在较大的参数范围内进行研究。在这里，发展了代理模型，它允许调整和提取Arrhenius参数，而不需要(有缺陷的)一维假设。此外，反应器中的体积与表面积的比率将被系统地改变，以能够明确地确定气相反应在有机金属化合物反应中的份额。目标一方面是在项目期结束时确定可靠的反应参数和反应机制，另一方面是在评估实际流动中的动力学数据方面取得方法学上的进展。

Organometallic compounds, such as ferrocene or aluminium acetylacetonate, are used to produce thin films and particles from the gas phase. For the most part, the reaction kinetics in the gas phase are not well studied, which makes rational process planning difficult or even impossible. In the first project phase, the thermal decomposition of three exemplary and important CVD precursors in the gas phase was investigated. With the help of the latest synchrotron-based mass spectrometric methods (i2PEPICO), the reaction mechanism for the conversion in inert gases could be determined much better and the first kinetic parameters were determined. The investigations took place in flow reactors, which were optimised using fluid mechanics simulations; temperature fields and residence times were also determined for microreactors using CFD simulations. In the continuation period applied for here, the reactions of the investigated CVD precursors with other reaction partners, such as water vapour, ethylene or hydrogen, are the focus of interest, as these are often used in gas-phase synthesis processes. Kinetic parameters and the reaction order of these reactions are to be investigated in a wide parameter range. Here, surrogate models are developed, which allow the adjustment and extraction of the Arrhenius parameters without the (flawed) assumption of one-dimensionality. In addition, the ratio of volume to surface area in the reactor will be systematically varied to be able to explicitly determine the share of the gas phase reactions in the reactions of the organometallic compounds. The goals are, on the one hand, to determine reliable reaction parameters and reaction mechanisms by the end of the project period and, on the other hand, to achieve methodological progress in the evaluation of kinetic data in real flows.