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Title: Transformer Coupled Toroidal Wave-Heated Remote Plasma Sources Operating in in Ar/NF 3 Mixtures
Abstract Remote plasmas are used in semiconductor device manufacturing as sources of radicals for chamber cleaning and isotropic etching. In these applications, large fluxes of neutral radicals (e.g., F, O, Cl, H) are desired with there being negligible fluxes of potentially damaging ions and photons. One remote plasma source (RPS) design employs toroidal, transformer coupling using ferrite cores to dissociate high flows of moderately high pressure (up to several Torr) electronegative gases. In this paper, results are discussed from a computational investigation of moderate pressure, toroidal transformer coupled RPS sustained in Ar and Ar/NF3mixtures. Operation of the RPS in 1 Torr of argon with a power of 1.0 kW at 0.5 MHz and a single core produces a continuous toroidal plasma loop with current continuity being maintained dominantly by conduction current. Operation with dual cores introduces azimuthal asymmetries with local maxima in plasma density. Current continuity is maintained by a mix of conduction and displacement current. Operation in NF3for the same conditions produces essentially complete NF3dissociation. Electron depletion as a result of dissociative attachment of NF3and NFxfragments significantly alters the discharge topology, confining the electron density to the downstream portion of the source where the NFxdensity has been lowered by this dissociation.  more » « less
Award ID(s):
2032604
PAR ID:
10527932
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
Institute of Physics
Date Published:
Journal Name:
Journal of Physics D: Applied Physics
ISSN:
0022-3727
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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