title: Application of a mid-infrared fiber bundle in remote measurement of gas concentrations in a chemical vapor deposition chamber.
abstract: A fiber bundle has been designed for measurement of gas concentrations in a chemical vapor deposition (CVD) chamber. The bundle is broadband, covering the spectrum range from 500 to 6000 cm(-1). Using this bundle, we have designed Fourier Transform infrared (FTIR) sampling configurations with reduced beam divergence (from 0.4 to 0.1 rad) and focal spot diameters (from 12 to 4 mm). The FTIR spectrum of tetraethoxysilane vapors in a CVD chamber was determined with the bundle and modified SAM connectors. An ellipsoid reflector was designed that yielded improved signal-to-noise ratios (SNR's) in the fiber-based spectra by a factor of 2. The incorporation of this reflector in spectrometers by use of the fiber bundle has the potential to reduce the sampling times for spectra while retaining acceptable SNR's.
authors.affiliation: Department of Physics, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick E3B 5A3, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Lu
authors.forename: X
authors.initials: X
authors.lastname: Bao
authors.forename: T
authors.initials: T
authors.lastname: Whidden
authors.forename: S Y
authors.initials: SY
authors.lastname: Lee