Optically Probing the Chemistry of Thin Film Processes

这项研究涉及光学诊断技术的发展，用于获得薄膜加工过程中发生在表面上和表面附近的化学的详细视图。这些原位技术用于识别代表性材料工艺中的化学步骤，特别是等离子体辅助化学蚀刻。拟议的工作包括两个相关的阶段。首先是开发和使用激光诱导热脱附（LITD）来研究在高电荷密度等离子体，特别是电子回旋共振等离子体中蚀刻过程中形成的稳态面层。这一层通常只有一层厚度，其形成和解吸的化学性质是理解蚀刻过程的关键。等离子体诱导光发射和激光诱导荧光（LIF）将用于检测解吸产物。激光诱导热解吸和其他光学探针将用于实时研究重要原型合金材料的ECR刻蚀。该研究的第二阶段是开发高空间分辨率的光学探针，用于图案薄膜加工，例如在表面上蚀刻带有图案掩模的薄膜。了解发生在暴露的薄膜和掩膜表面及其上方以及掩膜侧壁附近的化学反应的细节是很复杂的。提出的方法是用LIF探测表面附近的气体，用拉曼微探针光谱探测表面本身，有时同时进行，两者的横向分辨率都为1微米。这将在现场完成，通常是实时的。材料的加工通常主要取决于发生在其表面和表面附近的化学反应。这在微电子和光电子学的应用中是正确的，包括图案蚀刻和异质结构、单层和薄膜的原子层控制生长，在纳米制造中，以及在光学薄膜和保护涂层的制造中。然而，在这类材料的加工过程中，往往缺乏对化学步骤的基本理解。发生这种情况的部分原因是过程的复杂性，其中可能包括表面和上盖气相事件之间的相互作用，部分原因是缺乏诊断方法来识别物种并以足够的空间分辨率测量它们的浓度。本提案的相关目标是开发现场实时光学诊断，这对于获得这些化学过程的详细视图是必要的，并使用它们来识别几个关键但具有代表性的材料过程中涉及的化学步骤。

9411504 Herman This research is concemed with the development of optical diagnostic techniques for obtaining a detailed view of the chemistry that occurs on and near the surface during thin film processing. These in situ techniques are used to identify the chemical steps in representative materials processes, specifically plasma-assisted chemical etching. The proposed work consist of two related phases. The first is the development and use of laser-induced thermal desorption (LITD) to study the steady-state surface layer that is formed during etching in a high charge density plasma, specifically an ECR (electron cyclotron resonance) plasma. The chemistry of the formation and desorption of this layer, which is often only a monolayer thick, is key to understanding the etching process. Plasma-induced optical emission and laser induced fluorescence (LIF) will be used to examine the desorbed products. Laser-induced thermal desorption and other optical probes will be used to investigate the ECR etching of important prototype alloy materials in real time. The second phase of the proposed investigation is the development of high-spatial resolution optical probes of pattemed thin film processing, such as the etching of films with a pattemed mask on the surface. Understanding the details of the chemistry that occurs on and immediately above the surface of the exposed film and mask, and near the sidewalls of the mask, is complex. The proposed approach is to probe the gas near the surface with LIF and the surface itself wih Raman microprobe spectroscopy, at times simultaneously, both with 1 micron lateral resolution. This will be done in situ and usually in real-time. %%% The processing of materials often depends critically on the chemistry that occurs on and near the surface. This is true for applications in microelectronics and optoelectronics, which includes patterned etching and the atomic layer-controlled growth of heterostructures, monolayers and films, in nanoma nufacturing, and in the manufacture of optical films and protective coatings. However, a fundamental understanding of the chemical steps that occur is often lacking in such materials processing. This occurs, in part, because of the complex nature of the processes which may include the interplay between events on the surface and in the overlying gas phase, and, in part, because of a lack of diagnostics to identify species and to measure their concentrations with sufficient spatial resolution. The linked goals of this proposal are to develop in situ, real time optical diagnostics that are necessary to obtain a detailed view of these chemical processes, and to use them to identify the chemical steps involved in the processes of several key, yet representative, materials processes.