Elementary Steps in Plasma Chemistry

在实验物理化学项目中，约翰 马里兰州大学的摩尔和约翰·托塞尔将研究 电子-分子碰撞过程。 这样的过程 包括：解离电子附着，产生自由基和 负离子;直接离解，产生两个自由基;偶极 解离，导致同时产生阳性和 负离子;和解离电离，产生离子和负离子。 激进 该项目涉及实验和理论 表征这些过程，因为它们发生在气相中，以及 如在表面上。 选择用于研究的系统包括卤化碳， 卤代硅烷、卤代烯烃和卤代氟烃。 这些 前体及其产物被认为是理解 等离子体反应器中涉及的化学 蚀刻和半导体器件的制造。 气体中的放电产生了一个富含电子的环境 其在通常不反应的气体中引起化学变化。 这种高度 带电的混合物被称为等离子体，化学反应发生在 这就是所谓的等离子体化学。 这种反应堆已被广泛发现， 在半导体工业中用于制造材料和 装置. 这项研究将提供详细的信息， 参与这些反应的物种，以及基本的 了解他们的反应。

In this project in the Experimental Physical Chemistry Program, John Moore and John Tossell of the University of Maryland will investigate the processes involved in electron-molecule collisions. Such processes include: dissociative electron attachment, yielding a radical and a negative ion; direct dissociation, resulting in two radicals; dipolar dissociation, resulting in the simultaneous production of a positive and a negative ion; and dissociative ionization, yielding an ion and a radical. The project involves both experimental and theoretical characterization of such processes as they occur in the gas phase as well as on surfaces. Systems chosen for study include halocarbons, halosilanes, halogenated alkenes, and halofluorocarbons. These precursors and their products are thought to be crucial in understanding the chemistry involved in plasma reactors such as those used for plasma etching and in the fabrication of semiconductor devices. An electrical discharge in a gas creates an electron-rich environment which induces chemical changes in normally unreactive gases. This highly charged mixture is known as a plasma, and the chemical reactions taking place are termed plasma chemistry. Such reactors have found widespread use in the semiconductor industry for fabrication of both materials and devices. This research will provide detailed information on the nature of the species involved in such reactions, as well as fundamental knowledge of their reactions.