Parallelizability of helicon and inductively coupled plasma sources for large-area processing

Abstract

Since it was shown that the plasma processing throughput is proportional to the electron density, the development of an ultra-high-density plasma source has become a common goal related to plasma source technology and a number of studies have been performed to develop new high-density plasma sources such as electron cyclotron resonance plasma, inductively coupled plasma (ICP) and helicon plasma. Together with the development of high density plasma, recently, the development of large-area plasma source has become a hot issue in the plasma processing technology, as there is a continuous demand for large-area plasma processing such as semiconductor (>450mm), flat-panel display (>2mx2m), and photovoltaic cell (>1mx1m) processes. This trend in the area of large-area processes has motivated numerous studies for the development of a uniform large-area plasma source with high density. In this thesis, choosing ICP and helicon as a high density plasma source, parallelizability is investigated on the basis of measurements of the external and internal parameters for a single and multiple ICP and helicon sources. For comparative studies of those sources, the experimental conditions are same except the magnetic field. Through a computer simulation, the design of single helicon was optimized and the helicon and ICP was launched successfully. Secondly, the pressure effect was investigated. As the pressure increases, the electron-neutral collision frequency is reduced, thus the gyration motion of electrons by magnetic field is hindered and the characteristics are very similar to the ICP. Thirdly, the impedance varied depending on the position of the end plate. The power distribution is adjustable by changing it. Fourthly, the electron temperature was controllable by the gas mixture with helicon plasma like ICP. Fifthly, the electrical measurement showed that the impedance of the helicon discharge is higher than that of ICP discharge and decreases slowly with density. Since t...