Electron Interactions with C3F

By Cnrlstcphcrou, L. G.

Book Id: WPLBN0000659916
Format Type: PDF eBook:
File Size: 2.31 MB
Reproduction Date: 2005

Title:	Electron Interactions with C3F
Author:	Cnrlstcphcrou, 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 C3F. Retrieved from http://gutenberg.cc/

Description
Technical Reference Publication

Excerpt
Introduction: Perfluoropropane (C3b8) is a plasma processing gas and is a replacement for chlorofluorocarbons because it is not harmful to stratospheric ozone. However, like other similar compounds (e.g., CF4, and C2F6) it is a global warming gas. Its global warming potential over a 100-year period is 7000 compared to that of C02 taken equal to one and its lifetime in the stratosphere is 2600 years. By comparison, the respective global warming potentials of CF4 and C2F6 are 6500 and 9200, and the respective lifetimes 50 000 and 10 000. Ruoropropane is suitable for other applications. It has good thermal and chemical stability, low toxicity, relatively high vapor pressure, and is transparent to light from the infrared region down to about 1300 A. The magnitude and energy (or EIN. density-reduced electric field) dependence of its electron attachment rate constant and electron drift velocity make it suitable for possible use in externally sustained diffuse discharge especially as the electronegative component?

Table of Contents
Contents 1. Introduction.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. Electronic and Molecular Structure. . . . . . . . . . . . . 3. Electron Scattering. . . . . . . . . . . . . . . . . . . . . . . . . . 3.1. Total Electron Scattering Cross Section, U < ~ , ~ (.E.). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2. Momentum Transfer Cross Section (Elastic), urn(&) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3. Differential Elastic Electron Scattering Cross Section, . . . . . . . . . . . . . . . . . 3.4. Integral Elastic Electron Scattering Cross Section, ( T ~ . ~ ~ ~. (. E. .) .. . . . . . . . . . . . . . . . . . . 3.5. Differential Vibrational Excitation Cross Section, u v i b , d i f f i ~ ).. . . . . . . . . . . . . . . . . . . . . 3.6. Total Vibrational Inelastic Electron Scattering Cross Section, ( T , , ~ ~ ~ ~ ~. .~ . ,.~ . (. E ) . 4. Clcctron-Impact Ionization. . . . . . . . . . . . . . . . . . . . 4.1. Partial Ionization Cross Section, . . . 3.2. Total Ionization Cross Section, U , , , ( E ) . . . . . . 4 3 Total Dissnciative Crnss Section, U ~ ~ ~ , , ~ ( S ) 4.4. Ionization Coefficients. . . . . . . . . . . . . . . . . . . 4.4.1. Density-Reduced Ionization Coefficient. a l N . . . . . . . . . . . . . . . . . . 4.1.2. Effective Ionization Coefficient ( a - q)lN.. . . . . . . . . . . . . . . . . . . . . 4.4.3. ( EIN),i,,. . . . . . . . . . . . . . . . . . . . . . . . 4.4.1. Average Energy to Produce an Electron-Ion Pair. W.. . . . . . . . . . . . . . 5. Electron-Impact Dissociation Producing Neutrals.. 6. E l c r t ~un Attarllmcnt. . . . . . . . . . . . . . . . . . . . . . . . . 6.1. Density-Reduced Electron Attachment Coefficient. qiN. . . . . . . . . . . . . . . . . . . . . . . . 6 2 Total Electron Artar-hmenr Rate Concrnnt k.,,, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.1. k,,,(EIN) Measured in Pure C3F8. . . . 6.2.2. k,,JEIN) Measured in Binary Mixtures of C3Fs with Buffer Gases.. 6.2.3. k,,((e)). . . . . . . . . . . . . . . . . . . . . . . . . 6.2.4. Thermal Value, (ka,t)th, of the Total Electron Attachment Rate Constant.. . 6.3. Total Electron Attachment Cross Section, u,,,(E) and Total Dissociative Electron Attachment Cross Section, u ,,, ( E ) . . . . . . . . . 6.4. Dissociative Electron Attachment Fragment Anions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5. Effect of Temperature on k , , ( ( ~ ) ) and . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.6. Ncgativc Ions in C3r8 Plasmas. . . . . . . . . . . . . 7. Electron Transport. . . . . . . . . . . . . . . . . . . . . . . . . . 7.1. Electron Drift Velocity, w. . . . . . . . . . . . . . . . 7.2. Ratio of Transverse Electron Diffusion Coefficient to Electron Mobility DTlp. . . . . . 8. Summary of Cross Sections and Coefficients.. . . . 9. Needed Data.. . . . . . . . . . . . . . . . . . . . . . . . . . , , , . 10. Acknowledgments.. . . . . . . . . . . . . . . . . . . . . . . . . 1 1. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . List of Tables Definition of symbols.. . . . . . . . . . . . . . . . . . . . . . . lon~zat~othnr eshold energies tor C3F8.. . . . . . . . . Energies of negative ion states of C3F8. . . . . . . , . Recommended total electron scattering cross scction, ugC,,(c), for C3F8. . . . . . . . . . . . . . . . . . . . Momentum transfer (elastic) cross section. u,,(E), for C3F8.. . . . . . . . . . . . . . . . . . . . . . . . . . . Integral elastic electron scattering cross section. a,,;,,(&). fur C,F*. . . . . . . . . . . . . . . . . . . . . . . . . . . 7. Partial ionization cross sections, n,,,,,( E ). for .' Eirslronii. m:iil: filui;i.. chri..rophnrou@ ni. t.$oi C3Fs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 898 8. Suggested total ionization cross section, u , , , ( e ) , Ci 1993 h! the V S Sccrsr~r!. uf Coin~nerxo n hehalt oi'rhe C I : I ~S~rLat~e\ . for CIFs.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 899 .ill right.; rr.,r.r\ed. Thl, cop! r~gliri \ ~,\ignr.d to rhe .Atiicrli3n in'1r1rl1lc11 1' ~ h,IC), ~ n tdhe .-+nitnwnC herr~izalS o~,lr.t> 9. Total dissociation cross section. v ,,,,,, ( E ) . for