AVS 51st International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS-TuP

Paper PS-TuP20
Effects of Water Vapor on Plasma Parameters in Processing Plasmas

Tuesday, November 16, 2004, 4:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: Y. Ichikawa, Fuji Electric Device Technology Co., Ltd., Japan
Authors: Y. Ichikawa, Fuji Electric Device Technology Co., Ltd., Japan
M. Narita, Fuji Electric Device Technology Co., Ltd., Japan
K. Sasaki, Fuji Electric Device Technology Co., Ltd., Japan
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We have studied the effects of a trace amount of water vapor on the properties of processing plasmas by numerical analysis. In plasma processing for semiconductor applications such as sputtering and plasma CVD, oxygen is easily incorporated in the deposited films or in the ambience of plasma and seriously influences the properties of films and the performance of semiconductor devices. The principal source of oxygen is water vapor emitted from the wall of reaction chambers. Thus it is very important to understand the behavior of water vapor in processing plasmas. With a view to understanding the effect of water vapor on the processing plasma, we made a modeling of Ar positive column plasma; Ar is most popularly used for plasma processing in all the rare gases. The analytical method employed here is based on a positive column theory of Ichikawa and Teii.@footnote 1@ In the modeling, we took into account 6 ion species, Ar@super +@, Ar@sub 2@@super +@, H@sub 2@O@super +@, H@sub 3@O@super +@, OH@super +@, H@super +@ and meta-stable Ar. The reaction scheme among these species is very complicated, but assuming a small amount of H@sub 2@O in Ar, we can simplify the reaction system. The obtained results show that the abundance ratios of H@sub 2@O@super +@ and H@sub 3@O@super +@ become comparable to that of Ar+ even if a very small amount of H@sub 2@O, e.g. less than 1%, is added in Ar; these H@sub 2@O related ions increase with increasing gas pressure and chamber size. We will present the details of ion-molecule reactions used in the modeling for the Ar-H@sub 2@O plasma and numerical results. @FootnoteText@ @footnote 1@Y. Ichikawa and S.Teii, J. Phys. D, 13, 2031 (1980).