Research Initiation Awards: Kinetics of Diamond Film Growth

金刚石薄膜的火焰生长受衬底成核和生长物质通过热气体喷射形成的边界层扩散的控制。建议使用Questar显微镜通过原位长焦距显微镜来监测这些效应。用这台显微镜对撞击气体射流进行边缘观察，在15厘米处提供2微米的分辨率，将使我们能够绘制出整个沉积区边界层厚度的变化。这些信息将被用来研究气体流动对生长薄膜的热量和质量传递的影响。对衬底的直接高分辨率观察将使人们能够对生长的薄膜进行实时视频拍摄，并有助于澄清成核过程中的步骤。关于电化学沉积的工作将更具定性和探索性，因为还没有证明电化学金刚石沉积过程。寻找有用的工艺将试图利用与硅、锗和其他耐火半导体的电沉积类似的方法。近年来，国际上在低压低温金刚石薄膜生长领域进行了大量的研究工作。由于金刚石的最高性能，包括硬度、导热性和化学惰性，低成本金刚石在许多技术领域的潜在影响将是非常大的。本研究项目的目的是对几种有前景的金刚石薄膜生长技术的动力学进行实验研究，这些技术包括化学燃烧火焰生长、等离子体火焰生长和电化学沉积。

Flame growth of diamond films is controlled by nucleation on the substrate, and diffusion of the growth species through the boundary layer formed by the jet of hot gas. It is proposed to monitor these effects by in situ long focal distance microscopy using a Questar microscope. Edge-on observation of the impinging gas jet with this microscope, which provides 2 micron resolution at 15 cm, will allow us to map out the variation in the boundary layer thickness across the deposition area. This information will be used to study the effects of gas flow on the heat and mass transfer to the growing film. Direct high resolution observation of the substrate will allow one to make a real-time video of the growing film, and will help clarify the steps in the nucleation process. Work on electrochemical deposition will be more qualitative and exploratory, since no electrochemical diamond deposition process has yet been demonstrated. The search for a useful process will attempt to exploit analogies with electrodeposition of silicon, germanium and other refractory semiconductors. There has recently been an intense international research effort in the field of low pressure, low temperature diamond film growth. Because of the superlative properties of diamond, including hardness, thermal conductivity and chemical inertness, the potential impact of low cost diamond in many areas of technology would be very great. The goal of this research project is to investigate experimentally the kinetics of several promising diamond film growth techniques, including chemical combustion flame growth, plasma flame growth, and electrochemical deposition.