Analyses of Photo-induced Surface Reaction Processes during Plasma Sputtering

本项目的目的是阐明在反应等离子溅射过程中，光子注入材料表面的作用(特别是紫外光的作用)。已有的经验表明，在反应等离子体溅射(即反应离子刻蚀)过程中，光子注入对溅射性能有显著影响，但光诱导的非平衡表面化学反应的详细机制尚不清楚。在本项目中，我们使用分子动力学(MD)模拟和质量选择离子束注入系统，分析了各种刻蚀过程的表面反应机理，以阐明光子注入如何影响刻蚀性能。特别是在本财政年度，也就是本项目的最后一年，我们在以下方面做了工作：(1)用于MD模拟的激发原子的原子间势函数的建模以及光子与原子的相互作用。(2)基于从质量选择离子束注入系统获得的单能离子束和附加在离子束系统上的紫外光光源的同时注入实验，考察了离子束和光子注入的协同效应。通过这样的研究，我们评估了紫外光对反应离子刻蚀(即等离子体溅射)的影响，并阐明了工业上广泛使用的材料，如二氧化硅和一些有机聚合物，在反应离子刻蚀过程中表面反应的各种特征。

The goal of this project is to clarify the role of photon injections (especially those of ultra violet : UV) into the material surface during reactive plasma sputtering. It has been empirically known that, in reactive plasma sputtering (i.e., reactive ion etching) processes, photon injections significantly affect sputtering properties, but detailed mechanisms of the photo-induced non-equilibrium surface chemical reactions have been hardly known. In the present project, we have analyzed surface reaction mechanisms of various etching processes to clarify how photon injections can affect etching properties, using molecular dynamics (MD) simulations and a mass-selected ion beam injection system. Especially in this fiscal year, which is the final year of the present project, we have worked on the following topics : (1) Modeling of interatomic potential functions for excited atoms and interaction of photons and atoms in the material for MD simulations. (2) Examination of synergetic effects of ion beams and photon injections, based on the simultaneous injection experiments of a mono-energetic ion beam obtained from the mass selected ion beam injection system and light from a UV light source attached to the ion beam system. Through such research, we have evaluated effects of UV on reactive ion etching (i.e., plasma sputtering) and clarified various characteristics of surface reactions during reactive ion etching processes for materials widely used in the industry, such as silicon dioxide and some organic polymers.