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Developing Cross Section Sets for Fluorocarbon Etchants

Winstead, Carl and McKoy, Vincent (2002) Developing Cross Section Sets for Fluorocarbon Etchants. In: Atomic and Molecular Data and Their Applications. AIP Conference Proceedings. No.636. American Institute of Physics , Melville, NY, pp. 241-250. ISBN 0-7354-0091-1.

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Successful modeling of plasmas used in materials processing depends on knowledge of a variety of collision cross sections and reaction rates, both within the plasma and at the surface. Electron-molecule collision cross sections are especially important, affecting both electron transport and the generation of reactive fragments by dissociation and ionization. Because the supply of cross section data is small and measurements are difficult, computational approaches may make a valuable contribution, provided they can cope with the significant challenges posed. In particular, a computational method must deal with the full complexity of low-energy electron-molecule interactions, must treat polyatomic molecules, and must be capable of computing cross sections for electronic excitation. These requirements imply that the method will be numerically intensive and thus must exploit high-performance computers to be practical. We have developed an ab initio computational method, the Schwinger multichannel (SMC) method, that possesses the characteristics just described, and we have applied it to compute cross sections for a variety of molecules, with particular emphasis on fluorocarbon and hydrofluorocarbon etchants used in the semiconductor industry. A key aspect of this work has been an awareness that cross section sets, validated when possible against swarm data, are more useful than individual cross sections. To develop such sets, cross section calculations must be integrated within a focused collaborative effort. Here we describe electron cross section calculations carried out within the context of such a focused effort, with emphasis on fluorinated hydrocarbons including CHF3 (trifluoromethane), c-C_(4)F_(8) (octafluorocyclobutane), and C_(2)F_(4) (tetrafluoroethene).

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Additional Information:© 2002 American Institute of Physics. Issue Date: 21 October 2002. It is a pleasure to acknowledge collaboration with W. L. Morgan, P. D. Haaland, and their co-workers throughout the work described herein, as well as with H. Tagashira, K. Yoshida, and S. Goto in the development of a C2F4 cross section set. Work at Caltech was supported by Sematech, Inc., by the Department of Energy through the Office of Basic Energy Sciences, and by an equipment grant from Intel Corp. Calculations made use of the facilities of the Caltech Center for Advanced Computing Research and of the Jet Propulsion Laboratory's Supercomputing Project.
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Department of Energy (DOE)UNSPECIFIED
Subject Keywords:plasma applications; manufacturing processes; etching; carbon compounds; fluorine compounds; molecule-electron collisions; electron impact ionisation; electron impact dissociation; ab initio calculations
Series Name:AIP Conference Proceedings
Issue or Number:636
Classification Code:PACS: 52.77.Bn; 52.20.Fs; 52.20.Hv; 34.80.-i
Record Number:CaltechAUTHORS:20111109-140327494
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Official Citation:Developing Cross Section Sets for Fluorocarbon Etchants Carl Winstead and Vincent McKoy, AIP Conf. Proc. 636, 241 (2002), DOI:10.1063/1.1516341
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:27712
Deposited By: Jason Perez
Deposited On:09 Nov 2011 23:32
Last Modified:09 Nov 2021 16:51

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