AVS 52nd International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS-TuP

Paper PS-TuP17
Effect of Coulomb Collision on Oxygen Plasma

Tuesday, November 1, 2005, 4:00 pm, Room Exhibit Hall C&D

Session: Plasma Science and Technology Poster Session
Presenter: T. Furubayashi, Tohoku University, Japan
Authors: K. Nanbu, Tohoku University, Japan
T. Furubayashi, Tohoku University, Japan
Correspondent: Click to Email
Plasma processing has been used for fabricating semiconductors. The requirement of high aspect ratio etching is satisfied by using low pressure and high density plasmas. When simulating high density plasmas (n@sub e@ = 10@super 17@-10@super 18@m@super -3@), collision between charged particles should also be taken into consideration. Generally, in simulating plasma using the particle model, we consider only electron-molecule collisions and ion-molecule collisions. In this study, we consider not only such collisions but also electron-electron collisions using Bobylev and Nanbu method,@footnote 1@ because it is most probable that Coulomb collision have effect on the electron energy distribution. We examined the effects of Coulomb collision on plasma parameters. Especially, the effect on electron energy distribution function (EEDF) is important because it influences reaction rate of radicals production and hence, affects the etch rate. The effect of electron-electron collisions on argon plasma was examined previously,@footnote 2@ and we found that there is an effect on electron temperature but little effect on the EEDF. In this study, we simulated oxygen plasma using PIC/MC method considering four species, e@super -@, O@super +@, O@sub 2@@super +@, and O@super -@. The threshold energy of ionization in the collisional events of electron-oxygen collision is much lower than that of argon. So it is expected the electron-electron collisions have large effects on plasma parameters. @FootnoteText@ @footnote 1@ A. V. Bobylev and K. Nanbu, Phys. Rev, E, Vol.61(2000), pp. 4576-4586@footnote 2@ K. Nanbu, T. Furubayashi and H. Takekida, Thin Solid Film(to be published).