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）的目标是将TPCVD开发为用于高质量硬质膜和涂层的高速沉积的稳健工艺。 在1托至1个大气压的压力下的电感耦合射频等离子体用于沉积碳化硼和碳化硅的存款膜。 反应物是适当的氯化物蒸汽（硼氢化物或四氯化硅）和甲烷，注入氩-氢等离子体。 薄膜的特征在于几个异位技术，以确定元素组成，结晶度，形态，化学键，硬度和相关的机械性能。 薄膜的生长速率和性质与操作条件、表面温度和与生长表面相邻的流体边界层的化学性质有关。 分子束质谱法（MBMS）是用来获得在线测量的气相物质的摩尔分数在沉积过程中，这种技术可以提供绝对测量的摩尔分数的所有物种存在以上的检测限（ppm）的光谱仪。 利用MBMS测量技术建立了生长表面化学反应边界层的数值模型并进行了测试。 两名研究生正在接受涉及传热，等离子体科学，化学和材料科学的先进实验和计算方法的跨学科培训。 此外，一个新的诊断（MBMS）等离子体沉积研究的发展。

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.