Realistic Treatment of Plasma-Surface Interactions in Simulations of Low Temperature Plasmas: From a New Diagnostic to Optimization of Process Control

该项目将开发一种新的实验诊断和改进的计算模型，以表征材料表面与低温等离子体之间的相互作用，低温等离子体是由电子，离子和中性原子和分子组成的弱电离气体。 低温等离子体对现代生活至关重要，因为它们是制造各种高科技产品的基础，从笔记本电脑和智能手机到显示器和太阳能电池。它们还与各种医疗应用相关，例如医疗设备的灭菌和伤口愈合。所有这些应用都是基于等离子体以受控方式诱导不同表面反应的能力。为了优化这些应用，等离子体模拟，包括等离子体表面相互作用的现实实现，是至关重要的。在该项目中，将开发一种新的诊断方法来测量等离子体-表面相互作用物理学的关键方面，并将结果应用到计算模型中。从这项研究中获得的结果也将被纳入研究生水平的讲座低温等离子体science.Most电容射频等离子体（CCP）的模拟只包括恒定的离子诱导的电子发射和电子反射在猜测的概率。忽略对入射粒子能量、角度和表面材料以及其他影响的任何依赖性。这导致了粒子加热动态和通量能量分布函数（FEDF）的不正确描述。对于许多表面材料和气体的二次电子发射系数引起的电子，离子和中性的影响，以及粒子的反射和溅射率是未知的，在存在的等离子体，改变表面条件。在本计画中，我们将发展一种新的模拟诊断方法，利用光发射光谱法来量测电浆中的有效伽玛系数。现实的能量和表面依赖的电子发射和反射系数为不同的入射粒子物种，然后将实施到PIC模拟的CCP。 模拟代码将基准对实验和现实的表面系数对电子加热动力学和不同粒子种类的FEDFs的控制的影响进行了研究。 所有调查将结合联合收割机国家的最先进的模拟实验。

This project will develop a new experimental diagnostic and an improved computational model to characterize interactions between a material surface and a low temperature plasma, a weakly ionized gas composed of electrons, ions, and neutral atoms and molecules. Low temperature plasmas are essential for modern life as they form the basis for manufacturing a variety of high-technology products ranging from laptops and smartphones to displays and solar cells. They are also relevant for a variety of medical applications such as sterilization of medical equipment and wound healing. All these applications are based on the ability of the plasma to induce distinct surface reactions in a controlled way. In order to optimize these applications, plasma simulations, including a realistic implementation of plasma-surface interactions, are crucial. In this project, a new diagnostic to measure key aspects of the plasma-surface interaction physics will be developed, and results will be implemented into a computational model. Results obtained from this research will also be incorporated into graduate level lectures on low temperature plasma science.Most simulations of capacitive radio frequency plasmas (CCP) only include constant ion induced electron emission and electron reflection at guessed probabilities. Any dependencies on the incident particle energy, angle, and surface material as well as other effects are neglected. This leads to an incorrect description of the particle heating dynamic and flux-energy distribution functions (FEDF). For many surface materials and gases secondary electron emission coefficients induced by electron, ion, and neutral impact as well as particle reflection and sputter rates are unknown in the presence of plasmas that alter the surface conditions. In this project, a novel simulation based diagnostic to measure effective gamma-coefficient by Optical Emission Spectroscopy in the plasma will be developed. Realistic energy and surface dependent electron emission and reflection coefficients for different incident particle species will then be implemented into PIC simulations of CCPs. The simulation code will be benchmarked against experiments and the effects of realistic surface coefficients on the electron heating dynamics and the control of FEDFs of different particle species will be studied. All investigations will combine state-of-the-art simulations with experiments.