@article {4528,
title = {Elemental analysis with quadrupole mass filters operated in higher stability regions},
journal = {Journal of Analytical Atomic Spectrometry},
volume = {14},
number = {8},
year = {1999},
note = {ISI Document Delivery No.: 229LPTimes Cited: 23Cited Reference Count: 47},
month = {Aug},
pages = {1111-1119},
type = {Article},
abstract = {Operation of quadrupole mass filters in higher zones of stability is described with an emphasis on the potential for elemental mass spectrometry. The higher zones allow a resolution at half height of up to 9000 on atomic ions and make possible unit resolution on ions with kinetic energies up to several thousand electron volts. The theory of quadrupole operation is briefly reviewed. Operation of quadrupoles in the third stability region with Mathieu parameters (a,q)approximate to(3,3) and the second stability region with (a,q)approximate to(0.02, 7.55) is described in detail. Previously unpublished data showing the variation of resolution with ion energy are presented. The variation of transmission with resolution is compared with previous calculations and with new calculations presented here.},
keywords = {2ND, ANALYZER, ATMOSPHERE, DIAGRAM, HELIUM, HIGH-RESOLUTION, ICP-MS, SEPARATION MODE, SPECTROMETER, ZONE},
isbn = {0267-9477},
url = {://000082196300002},
author = {Du, Z. H. and Douglas, D. J. and Konenkov, N.}
}
@article {7356,
title = {THE DYNAMICS OF HOT-F ATOMS IN LOW-PRESSURE PLASMA-ETCHING REACTORS},
journal = {Chemical Physics},
volume = {166},
number = {3},
year = {1992},
note = {ISI Document Delivery No.: JR214Times Cited: 2Cited Reference Count: 26},
month = {Oct},
pages = {317-328},
type = {Article},
abstract = {The time dependent distribution function of translationally energetic F atoms produced by electron impact dissociative collisions with CF4 in a low pressure CF4 plasma is determined from the solution of the Boltzmann equation. The hot F atom distribution function departs from equilibrium owing to the strength and energy distribution of the source atoms and is driven to equilibrium via F-CF4 elastic collisions. The extent of the departure from equilibrium depends on the rate of production of hot F atoms by reaction and the rate of thermalization by elastic collisions. The time dependent hot F distribution function is determined from the Boltzmann equation for an initial non-equilibrium distribution, with and without a steady source. The differential elastic collision cross section for F-CF4 collisions, that defines the collision operator in the Boltzmann equation, is calculated quantum mechanically. The phase shifts are determined with the WKB approximation for an appropriate Lennard-Jones 6-12 potential for the F-CF4 interaction. The results of these calculations suggest that hot neutral F radicals may contribute to the etching process and be competitive with ion activated etching. The enhancement of reaction rates owing to energetic F atoms is also determined and compared with the corresponding thermal rates.},
keywords = {ATMOSPHERE, DISCHARGES, GAS},
isbn = {0301-0104},
url = {://A1992JR21400003},
author = {Shizgal, B. and Clarke, A. S.}
}