Quantifying Plasma-Surface Interactions: Charge Exchange, Energy Losses, Fragmentation, and Reactions

CTS-0613981 Award AbstractTitle：Quantifying Plasma-Surface Interactions：Charge Exchange，Energy Losses，Fragmentation，and Reactions本研究的重点是高能离子与表面碰撞时会发生什么，并解决了等离子体与表面相互作用中的长期问题。离子-表面碰撞在许多表面敏感分析技术中是至关重要的。 它们在工业过程中也是必不可少的，例如等离子体蚀刻和沉积，两者都是半导体芯片制造中不可或缺的。尽管它们的重要性，等离子体表面相互作用的理解已经落后于应用，迫使过程开发繁琐，耗时，昂贵的试错。这种理解可以通过离子束实验获得，而这些实验本身是非常难以进行的。一个独特的和强大的离子束线散射装置，定制内置在PI的小组在过去6年与NSF和工业的支持，使拟议的研究成为可能。 该装置利用等离子体提取和纯化离子，如氟和碳的氟化物，然后将其输送到接地的样品表面，并允许其与接地的样品表面相互作用，如硅，铝和氧化硅，所有这些在制造微处理器中都很重要。使用灵敏的质谱仪和能量分析仪监测相互作用的结果，以推断身份并测量散射产物的能量。要研究的具体现象包括表面的电荷交换、离子碎裂、由于量子力学效应引起的能量损失和反应机制。将产生散射相互作用的详细图片，包括蚀刻产率和反应产物作为入射能量和角度的函数。这些实验将通过分子动力学模拟来补充，以提高对原子的理解。广泛影响：这项研究预计将产生的结果是基本的，足以被理论家用于验证束表面相互作用的原子模拟和实用的足够有用的工艺工程师选择化学和操作条件的快速优化等离子体工具。其目的是建立一个新的模式，在蚀刻工艺的发展，通过基本的光束散射实验和蚀刻轮廓演变模拟相结合，从而加快发展新的蚀刻工艺的半导体制造。通过这些实验获得的知识和理解将被纳入等离子体表面相互作用的课程和教程中，以教育学生和工程师了解化学反应动力学的基本原理。此外，一个新的，低成本的实验涉及大气微等离子体直接图案化的硅将介绍等离子体表面相互作用的本科生。

CTS-0613981 Award AbstractTitle: Quantifying Plasma-Surface Interactions: Charge Exchange, Energy Losses, Fragmentation, and ReactionsThis research focuses on what happens when energetic ions collide with surfaces and addresses long-standing issues in plasma-surface interactions. Ion-surface collisions are of paramount importance in many surface-sensitive analytical techniques. They are also essential in industrial processes, such as plasma etching and deposition, both indispensable in semiconductor chip fabrication. In spite of their significance, understanding of plasma-surface interactions has lagged behind applications, forcing process development by cumbersome, time-consuming, and costly trial and error. Such understanding can be obtained through ion beam experiments, which are themselves very difficult to perform. A unique and powerful ion-beamline scattering apparatus, custom-built in the PI's group over the last 6 years with NSF and industrial support, makes the proposed research possible. The apparatus utilizes plasmas to extract and purify ions, such as fluorine and carbon fluorides, which are then transported to and allowed to interact with a grounded sample surface, such as silicon, aluminum, and silicon oxide, all important in fabricating microprocessors. The outcome of the interaction is monitored using sensitive mass spectrometers and energy analyzers to infer the identity and measure the energy of the scattered products. Specific phenomena to be studied include charge exchange at surfaces, ion fragmentation, energy losses due to quantum mechanical effects, and reaction mechanisms. A detailed picture of the scattering interaction will be produced including etch yields and reaction products as a function of incident energy and angle. The experiments will be complemented by molecular dynamics simulations to improve atomistic understanding. Broad Impact: This research is expected to generate results that are fundamental enough to be used by theorists for validating atomistic simulations of beam-surface interactions and practical enough to be useful to process engineers for selecting chemistries and operating conditions for rapid optimization of plasma tools. The intent is to establish a new paradigm in etch process development through a combination of fundamental beam scattering experiments and etch profile evolution simulations, thus speeding up the development of new etch processes for semiconductor fabrication. Knowledge and understanding obtained through these experiments will be incorporated in courses and tutorials on plasma-surface interactions to educate students and engineers on the underlying principles of chemical reaction dynamics. In addition, a new, low-cost experiment involving atmospheric microplasmas in direct patterning of silicon will introduce plasma-surface interactions to undergraduates.