Electron Interactions with C12

By Cnrtstoehorou, L. G.

Book Id: WPLBN0000660198
Format Type: PDF eBook:
File Size: 4.30 MB
Reproduction Date: 2005

Title:	Electron Interactions with C12
Author:	Cnrtstoehorou, L. G.
Volume:
Language:	English
Subject:	Technology., Reference materials, Technology and literature
Collections:	Techonology eBook Collection
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Citation APA MLA Chicago G. Christophoro, B. L. (n.d.). Electron Interactions with C12. Retrieved from http://gutenberg.cc/

Description
Technical Reference Publication

Excerpt
Introduction: Molecular chlorine (C12) is a plasma processing gas (e.g., see Refs. 1-24). It is used in plasma etching of semiconductors where the C1 atoms produced in a gas discharge efficiently etch a silicon surface. The dominant primary electron interaction processes are taken to be single-step electron impact ionization of C12 and C1, dissociation of C1, into neutrals, and dissociative attachment to C12 17'0,13317 The basic species involved in C12 plasmas, then, are the three molecular species: C12, Cli, and l:, and the three atomic species?C1, C1-, and elf. Although recent work on the interactions of C12 with slow electrons is largely motivated by plasma etching technology, considerable work on electron interactions with the C1, molecule was done in the 1970s and the 1980s motivated by gas ultraviolet (W) laser applications. 25-31 In this latter application the fundamental process of interest is dissociative electron attachment producing halogen atomic negative ions (Cl-) which efficiently recombine?

Table of Contents
Contents 1. Introduction ................................ 133 2. Electronic and Molecular Structure. ............ 135 2.1.C12 ................................... 135 2.2. C1,. .................................. 139 2.3.cl; ................................... 139 3. Electron Scattering for Cl,. ................... 140 3.1. Total Electron Scattering Cross Section, U ~ ~ ,.~..(.E..). ......................... 140 3.2. Total Rotational Electron Scattering Cross Section, ....................... 141 3.3. Total Elastic Electron Scattering Cross Section. a,,(&). ........................ 143 3.4. Momentum Transfer Cross Section, a,(&) ... 143 3.5. Inelastic Electron Scattering Cross Section, cine,(&).,. ............................. 145 3.5.1. Rotational Excitation Cross Section, u r o l ( ~..). ........................ 145 a)~lecbonimc ail: loucas.christophorou@nist.gov 01999 by the U.S. Secretary of Commerce on behalf of the United States. All rights reserved. This copyright is assigned to the American Institute of Physics and the American Chemical Society. Reprints available from ACS; see Reprints List at back of issue. 3.5.2. Total Vibrational Excitation Cross Section, U ~ ~ ~ ,.~..(.E..).... ......... 3.5.3. Electronic Excitation Cross Sections, udec(&). ......................... 4. Electron Impact Ionization for Clz. ............ 4.1. Total Ionization Cross Section, U ~ , ~ (.E.)... . 4.2. Density-Reduced Electron-Impact Ionization Coefficient, a/N(EIN). .................. 5. Total Cross Section for Electron-Impact Dissociation into Neutral Fragments, udissreut,t(~) for Clz.. .................................. 6. Elcctron Attachment to C12. .................. 6.1. Total Dissociative Electron Attachment Cross Section, .................. 6 :! Tntal El~ctrnnA ttachment Rate Constant as a Function of the Density-Reduced Electric Field EIN, k,,(EIN), and the Mean Electron Energy (E), k, , ( ( E ) ) . ............. 6.2.1. k , , ( E / N ) in N2. ................... 6.2.2. k , , ( ( e ) ) . ......................... 6.2.3. Thermal value, ( k , J m , of the Total Electron Attachment Rate Constant.. .. 0047-2689/99/28(1)1131/39/$31.00 131 J. Phys. Chem. Ref. Data, Vol. 28, No. 1, 1999