Research Initiation Awards: Kinetics of Diamond Film Growth

金刚石薄膜的火焰生长受基体上的成核和热气体射流形成的边界层中生长物质的扩散控制。建议使用Questar显微镜原位长焦距显微镜监测这些影响。这台显微镜在15厘米处提供2微米的分辨率，对撞击气体射流的侧面观察将使我们能够绘制出沉积区域边界层厚度的变化。这些信息将用于研究气体流动对生长膜的传热和传质的影响。对衬底的直接高分辨率观察将允许人们制作生长薄膜的实时视频，并将有助于阐明成核过程中的步骤。电化学沉积的工作将更加定性和探索性，因为电化学金刚石沉积工艺尚未得到证实。寻找一种有用的工艺将试图利用与硅、锗和其他难熔半导体的电沉积的类比。近年来，国际上在低压、低温金刚石膜生长领域进行了大量的研究。由于金刚石具有极高的性能，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巨大的。本研究项目的目的是通过实验研究几种有前途的金刚石膜生长技术的动力学，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.