Optically Probing the Chemistry of Thin Film Processes

该项目的目标是通过获得在薄膜过程中发生在表面上的化学成分的详细视图来确定等离子体辅助化学蚀刻电子材料的化学步骤。方法是使用已经开发的表面光学探测器，并根据需要开发和使用新的表面敏感光学探测器，并利用现有的诊断技术来探测等离子体。几种关键材料，包括硅、氮化镓和碳化硅，将在几种环境中进行研究，包括C12和C12/Ar高电荷密度等离子体，以了解对这些材料工艺有贡献的分子和表面过程。激光诱导热解吸(LITD)是一种表面敏感的光学探头，将用于研究在电感耦合等离子体(ICP)中刻蚀过程中形成的稳态表面层。有时只有单分子层厚的这一层的形成和解吸的化学被认为是理解刻蚀过程的关键。基于激光解吸的方法将被用来原位和实时探测等离子体刻蚀。在可能的情况下，将使用激光诱导荧光(LIF)来检测解吸产物。当激光诱导荧光检测不可能或不可行时，将监测激光解吸后等离子体诱导发射(PIE)的瞬时增加，以检测解吸的产物。这一LD-PIE方法将作为拟议工作的一部分加以开发。初步研究表明，LD-PIE分析具有亚单分子层灵敏度。其他诊断方法将用于表征等离子体和刻蚀过程，如光发射辐射测量法、朗缪尔探测法和微波干涉测量法。%该项目解决具有高潜在技术相关性的材料科学主题领域的基础研究问题。这项研究将在基础水平上为电子/光子器件的重要制造方面贡献基础材料科学知识。现在有了新的实验光学工具，可以对基本表面过程进行更详细的观察，如果更好地了解这些过程，就可以推动基础科学和技术的进步。从研究中获得的基本知识和理解有望有助于提高先进器件和电路的性能和稳定性。该计划的一个重要特点是通过在一个具有根本意义和技术意义的领域对学生进行培训，将研究和教育结合起来。

The goal of this project is to identify the chemical steps in plasma-assisted chemical etching of electronic materials by obtaining a detailed view of the chemistry that occurs on the surface during this thin film process. The approach is to use optical probes of the surface, those that have been developed, and by developing and employing new surface-sensitive optical probes as needed, and by utilizing existing diagnostic techniques to probe the plasma. The etching of several key materials, including Si, GaN, and SiC, will be studied in several environments, including C12 and C12/Ar high charge density plasmas, to understand the molecular and surface processes that contribute to these materials processes. Laser-induced thermal desorption (LITD), a surface sensitive optical probe, will be used to study the steady-state surface layer that is formed during etching in an inductively coupled plasma (ICP), a prominent type of high charge density plasma. The chemistry of the formation and desorption of this layer, which is sometimes only a monolayer thick is considered key to understanding the etching process. Laser-desorption based methods will be used to probe in situ and in real time the plasma etching. When possible, laser induced fluorescence (LIF) will be used to examine the desorbed products. When LIF detection is not possible or feasible, the transient increase in plasma-induced emission (PIE) after laser desorption will be monitored to detect desorbed products. This LD-PIE method will be developed as part of the proposed work. Preliminary studies have shown that LD-PIE analysis can have submonolayer sensitivity. Other diagnostics will be used to characterize the plasma and the etching process, such as optical emission actinometry, Langmuir probing, and microwave interferometry.%%%The project addresses basic research issues in a topical area of materials science having high potential technological relevance. The research will contribute basic materials science knowledge at a fundamental level to important fabrication aspects of electronic/photonic devices. New experimental optical tools are now available to allow more detailed observation of elementary surface processes which when better understood allow advances in fundamental science and technology. The basic knowledge and understanding gained from the research is expected to contribute to improving the perform-ance and stability of advanced devices and circuits. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area.***