In Situ Studies of Tetrahedrally Bonded Thin Film Nucleation, Surfaces, and Interfaces

提出的研究计划的目的是获得对四面体协调薄膜表面和界面的结构和性质及其与沉积的物理和化学关系的基本理解。由于等离子体沉积过程的复杂性，以及相对缺乏用于研究表面和界面成核和反应的原位探针，特别是在不利的高压等离子体环境中，薄膜科学在这些方面的进展非常缓慢。原位光谱椭偏技术（SE）是一种单层敏感、无微扰的技术，可用于解决这些问题。一种独特的基于光学多通道分析仪的椭偏系统现在可以收集1.1 eV到4.5 eV的介电函数光谱，最小时间分辨率小于1秒。这样就可以在这些薄膜生长的每一埃处拍摄光谱。根据这项建议还将拟订第二份文书。所研究的材料是氢化和无氢的非晶碳和硅以及微晶金刚石。制备能力将包括等离子体增强化学气相沉积（CVD），加热灯丝增强CVD，远程等离子体CVD，全部来自CH4或SiH4。物理气相沉积技术包括蒸发，有或没有离子辅助，直流平面磁控溅射和离子束溅射。研究将集中在微晶金刚石薄膜的成核和界面结构，以及它们的表面对表征良好的惰性和活性离子束的响应。类似的实验将用于探测si基薄膜的成核、表面反应性和键合。这些实验将用于确定控制薄膜结合和形态的物理因素。

The aim of the proposed research program is to obtain a fundamental understanding of the structure and properties of tetrahedrally coordinated thin film surfaces and interfaces and their relationship to the physics and chemistry of deposition. Progress in these aspects of thin film science has been very slow owing to the complexity of the plasma processes for deposition and the relative lack of in situ probes for studying nucleation, and reactions at surfaces and interfaces, particularly in adverse high pressure plasma environments. In situ spectroscopic ellipsometry (SE) is a monolayer-sensitive, non-perturbative technique which will be applied to these problems. A unique optical multichannel analyzer-based ellipsometry system in place now permits collection of dielectric function spectra from 1.1 eV to 4.5 eV with a minimum time resolution of less than one second. This allows spectra to be taken at every Angstrom during the growth of these films. A second instrument will also be developed under this proposal. The materials to be studied are hydrogenated and hydrogen-free amorphous carbon and silicon as well as microcrystalline diamond. The preparation capabilities will include plasma enhanced chemical vapor deposition (CVD), heated filament enhanced CVD, remote plasma CVD, all from CH4 or SiH4. Physical vapor deposition techniques include evaporation, with and without ion assist, dc planar magnetron sputtering, and ion beam sputtering. The studies will concentrate on the nucleation and interface structure of microcrystalline diamond thin films and the response of their surfaces to well- characterized inert and reactive ion beams. Similar experiments will be used to probe the nucleation, surface reactivity, and bonding for the Si-based films. These experiments will be used to identify the physical factors which control film bonding and morphology.