ION AND NEUTRAL VELOCITY DISTRIBUTIONS IN MULTI-ION PLASMA SHEATHS

多离子等离子体鞘中的离子和中性速度分布

• 批准号: 0713784
• 负责人: EARL SCIME
• 金额: --
• 依托单位: West Virginia University Research Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0713784&HistoricalAwards=false
• 关键词: ION; NEUTRAL; VELOCITY; DISTRIBUTIONS; MULTI

The proposal is directed at investigating the physics of multi-ion sheaths, the generation of supersonic fluxes of energetic ions in spontaneously forming double layers (sheaths), and the creation of fluxes of energetic neutrals that could be used for plasma-aided etching. Neutral etching avoids the problem of substrate charging that occurs when energetic ions are used to etch wafers in the microelectronics industry. The acceleration of ions through sheaths in multi-ion plasmas is a fundamental plasma physics question with important ramifications for systems ranging from space plasmas to fusion plasmas. There are two primary objectives of this proposal. First is the determination of the effect of additional ion species on double layer formation in expanding helicon plasmas, and second, the measurement of the momentum coupling between ions and neutral atoms in the layer due to charge exchange processes. The essential intellectual merit of the proposed activity will be the first detailed measurement of the flow velocities of two different ion species and a single neutral species in a plasma sheath. Ion acceleration through pre-sheaths and sheaths in multi-ion plasmas is not fully understood and this project will make a significant contribution to this active area of fundamental plasma science research. The broader impact of the work involves the training of graduate students in a research environment that emphasizes the synergy between basic and applied plasma physics; improvement of the percentage of women obtaining advanced degrees in physics; and attracting high quality undergraduates into physics through involvement in cutting-edge research activities. Impact on the field of plasma etching of semiconductors is also likely since production of significant fluxes of energetic neutral atoms through charge exchange neutralization of the double layer accelerated ions would provide a new means of etching features in silicon at scales of less than ten nanometers. Impact on the field of plasma propulsion is also likely given that plasma detachment from plasma-based thrusters is an important and unresolved question.

该提案旨在研究多离子鞘层的物理特性、自发形成双层（鞘层）时高能离子超音速通量的产生，以及可用于等离子体辅助蚀刻的高能中性粒子通量的产生。中性蚀刻避免了微电子行业中使用高能离子蚀刻晶圆时出现的基板带电问题。多离子等离子体中离子穿过鞘层的加速是一个基本的等离子体物理问题，对从空间等离子体到聚变等离子体的系统都有重要影响。该提案有两个主要目标。首先是确定附加离子种类对膨胀螺旋等离子体中双层形成的影响，其次是测量层中离子和中性原子之间由于电荷交换过程而产生的动量耦合。拟议活动的基本智力价值将是首次详细测量等离子体鞘中两种不同离子物质和单个中性物质的流速。多离子等离子体中通过预鞘和鞘的离子加速尚未完全了解，该项目将为基础等离子体科学研究的这一活跃领域做出重大贡献。这项工作更广泛的影响包括在强调基础等离子体物理学和应用等离子体物理学之间协同作用的研究环境中对研究生进行培训；提高获得物理学高级学位的女性比例；通过参与前沿研究活动吸引高素质本科生进入物理学领域。对半导体等离子蚀刻领域的影响也很可能，因为通过双层加速离子的电荷交换中和产生显着的高能中性原子通量将提供一种在小于十纳米尺度的硅中蚀刻特征的新方法。鉴于等离子体与等离子体推进器的分离是一个重要且尚未解决的问题，也可能对等离子体推进领域产生影响。