Although various kinds of plasma production techniques have been proposed recently, capacitively coupled radio-frequency (RF) plasma (CCP) still locates at the main source in plasma processing such as etching, sputtering and chemical vapor deposition.[1] The CCP, however, has been required to increase the plasma density from 10⁹cm^-3 to 10¹⁰-10¹¹cm^-3 for development of CCP.[1] In order to realize the high-density production in CCP, the discharge technique should be improved. In general, the discharge sustaining mechanism would be mainly collisional ionization caused by stochastic heating of electrons interacted with oscillating RF sheath in front of RF powered electrode.[1] That means that the mechanism does not always need secondary electrons which are emitted from cathode electrode due to incident positive ions like DC and AC discharges. On the contrary, we have proposed the combination of an ionization mechanism caused by secondary electrons with the main discharge mechanism of CCP to perform high density production. In order to emphasize the ionization due to secondary electrons, the oxide materials have been used as electrodes. It is well-known that for microdischarge as seen in plasma display panel, oxide materials such as oxide magnesium (MgO) have high secondary electron coefficient which is higher than 0.1.[2] Thus, using these oxide materials, a large amount of secondary electrons are possible to contribute an ionization process so that high density production can be performed in CCP. In this work, influences of oxide material on CCP discharge were investigated to perform the high density production. It was found to achieve plasma density of 5×10¹⁰cm^-3 using MgO electrodes, while the Al electrodes produced 10⁹cm^-3.

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