Fundamental Studies of Thermal Plasma Chemical Vapor Deposition

这是热等离子体化学气相沉积的基础研究。（TPCVD）的目标是发展TPCVD作为高速率沉积高质量硬膜和涂层的稳健工艺。在1torr到1atmosphere的压力下，使用电感耦合射频等离子体沉积碳化硼和碳化硅薄膜。反应物是适当的氯化物蒸气（三氯化硼或四氯化硅）和甲烷，注入氩氢等离子体。薄膜的特征是通过几种非原位技术来确定元素组成，结晶度，形态，化学键合，硬度和相关的机械性能。薄膜的生长速率和性能与操作条件、表面温度和邻近生长表面的流体边界层的化学性质有关。分子束质谱（MBMS）用于在线测量沉积过程中气相物质的摩尔分数；该技术可以提供绝对测量摩尔分数的所有物种存在的检测限（ppm）以上的光谱仪。在生长表面的化学反应边界层的数值模型被开发和测试使用MBMS测量。这个主题是潜在的主要使能技术生产耐磨损和耐化学侵蚀的涂层。两名研究生正在接受涉及传热、等离子体科学、化学和材料科学的高级实验和计算方法的跨学科培训。此外，还开发了一种新的等离子沉积诊断方法（MBMS）。

Abstract-GirshickThis is a fundamental study of thermal plasma chemical vapor deposition. (TPCVD) with the objective of developing TPCVD as a robust process for the high-rate deposition of high-quality hard films and coatings. An inductively coupled radio-frequency plasma at pressures of 1 Torr to 1 atmosphere is used to deposit films of boron carbide and silicon carbide. Reactants are the appropriate chloride vapor (boron trichloride or silicon tetrachloride) and methane, injected into an argon-hydrogen plasma. Films are characterized by several ex-situ techniques to determine elemental composition, crystallinity, morphology, chemical bonding, hardness and related mechanical properties. Film growth rates and properties are related to operating conditions, surface temperature, and the chemistry of the fluid boundary layer adjacent to the growth surface. Molecular-beam mass spectrometry (MBMS) is used to obtain on-line measurements of mole fractions of gas-phase species during deposition; this technique can provide absolute measurements of mole fraction for all species present above the detection limit (ppm) of the spectrometer. Numerical models of the chemically reacting boundary layer at the growth surface are developed and tested using MBMS measurementsThis topic is potentially a major enabling technology for production of coatings resistant to abrasion and chemical attack. Two graduate students are receiving interdisciplinary training in advanced experimental and computational methods involving heat transfer, plasma science, chemistry, and materials science. In addition, a new diagnostic (MBMS) for plasma deposition studies is developed.