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

CTS-0613981奖摘要标题：量化等离子体-表面相互作用：电荷交换、能量损失、碎裂和反应这项研究侧重于高能离子与表面碰撞时会发生什么，并解决等离子体-表面相互作用中的长期问题。在许多表面敏感分析技术中，离子-表面碰撞是至关重要的。它们在工业过程中也是必不可少的，例如等离子刻蚀和沉积，这两者都是半导体芯片制造中不可或缺的。尽管它们意义重大，但对等离子体-表面相互作用的了解一直落后于应用，迫使工艺开发通过繁琐、耗时和代价高昂的试验和错误。这样的理解可以通过离子束实验来获得，而离子束实验本身就很难进行。过去6年里，PI的团队在NSF和工业支持下定制了一种独特而强大的离子束线散射设备，使拟议的研究成为可能。该仪器利用等离子体来提取和提纯氟和碳氟化物等离子，然后将这些离子输送到接地的样品表面并允许其与其相互作用，这些表面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，以推断散射产物的身份和测量能量。需要研究的具体现象包括表面电荷交换、离子碎裂、量子力学效应造成的能量损失以及反应机理。将产生散射相互作用的详细图像，包括作为入射能量和角度的函数的蚀刻产额和反应产物。这些实验将得到分子动力学模拟的补充，以提高对原子的理解。广泛的影响：这项研究预计将产生足够基本的结果，足以被理论家用来验证束-表面相互作用的原子模拟，并且足够实用，足以有助于工艺工程师为快速优化等离子体工具选择化学物质和操作条件。其目的是通过基本束散射实验和刻蚀轮廓演化模拟的结合，建立刻蚀工艺开发的新范式，从而加快半导体制造新刻蚀工艺的开发。通过这些实验获得的知识和理解将被纳入关于等离子体-表面相互作用的课程和教程中，以教育学生和工程师化学反应动力学的基本原理。此外，一项新的、低成本的实验将向本科生介绍等离子体-表面相互作用，该实验涉及大气微等离子体在硅的直接图案化中。

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.