Gas/Surface Interaction Study Applied to Si-based Materials Used in Driven Micro- and Nano-scale Devices

摘要

A hot filament method is used to study the heat transfer between tungsten surface and hollow cathode glow discharge plasmas in argon and CO2. The dependence of the electric power supplied to a tungsten wire on the discharge current is determined for argon and carbon dioxide in the temperature range between 1000K and 1700 K. A difference in heat transfer at the tungsten wire surface is found between experiments on argon and carbon dioxide. The difference is attributed to heterogeneous recombination in CO2 plasma. It is hardly possible to enumerate all applied and fundamental issues related to energy transfer across plasma-solid interfaces. Problems of this kind arise in areas ranging from aerothermodynamics to plasma enhanced chemical vapor deposition, sputtering, and etching technologies. Therefore, research on this subject is important from both theoretical and practical perspectives. Of particular importance are further experimental studies using various techniques with a view to improving theoretical models of plasma- surface interaction. The choice of a hot filament technique, widely used in studies of heat transfer in low pressure gas-surface systems starting from Knudsen's work, has the technical advantage of simple processing control. Tungsten is used as a filament material for the following reasons. First, tungsten is a metal with well-known electrical and thermal properties. Second, it has a high melting point of 3653 K, which makes it possible to conduct investigations in a wide temperature range. Moreover, a vast amount of data is available on heat and mass transfer at tungsten surface.