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Indexed by:会议论文

Date of Publication:2003-06-02

Included Journals:EI、Scopus

Page Number:185-

Abstract:Radio-frequency (RF) gas discharges are widely used in the microelectronics industry, such as stripping of photoresist, depositing of organic and inorganic thin films, and anisotropic etching of semiconductor, oxide and metal surfaces. In the plasma processing, the ion energy distributions (IEDs) bombarding the substrates would strongly affect the surface reactions and film etching rates. Meanwhile, the ion angular distributions (IADS) would influence etching profiles. Additional, some processing discharge pressure have been up to hundreds of mtorr, which would lead to that the ion mean free path decreases and is close to the Debye length. Thus, the effects of the ion-neutral collisions in the RF sheath on the IEDs and IADs have to be taken into account. In this paper, a self-consistent dynamics model suitable for describing collisional RF sheaths driven by a sinusoidal current source is proposed. This model retains all the time-dependent terms in the ion fluid equations, which commonly ignored in some analytical models and numerical simulations of collisional sheaths for simplifying the ion dynamics. Additional, an equivalent circuit model is coupled to the fluid equations in order to self-consistently determine the relationship between the instantaneous potential at a rf-biased electrode and the sheath thickness. Making use of the electric field obtained by the self-consistent model, the ion transport motion in the RF sheath are simulated by the Monte-Carlo method. The collisional effects on the IEDs and the IADs are studied for various discharge pressures and plasma parameters.