Imaging with ion beams and laser postionization

Journal Article · Mon Aug 01 04:00:00 EDT 1994 · Analytical Chemistry (Washington); (United States)

DOI:https://doi.org/10.1021/ac00087a004· OSTI ID:6915330

Wood, M; Zhou, Y; Brummel, C L; Winograd, N ^[1]

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1. Pennsylvania State Univ., University Park, PA (United States)

We investigate the use of a liquid metal ion gun (LMIG) combined with multiphoton resonance ionization of sputtered atoms and/or molecules to acquire mass-selected images with submicrometer spatial resolution. Images from several model systems are presented including those of an In grid, and of patterned surfaces of benzo[a]pyrene and tryptophan thin films. Since postionization for these systems yields ionization efficiencies that are considerably higher than those achieved with secondary ion mass spectrometry (SIMS), spatial resolution of 2600 [angstrom] for molecular species could be achieved while static conditions were maintained. Cooling of the sample to <210 K was shown to be essential for molecular systems since the number of thermally evaporating molecules overwhelms the number of sputtered molecules at room temperature. Other details necessary to incorporate laser postionization into a time-of-flight SIMS instrument using a pulsed LMIG source are also discussed. 30 refs., 9 figs.

• OSTI ID: 6915330
• Journal Information: Analytical Chemistry (Washington); (United States), Journal Name: Analytical Chemistry (Washington); (United States) Vol. 66:15; ISSN 0003-2700; ISSN ANCHAM
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical &amp; Spectral Procedures
400201 -- Chemical &amp; Physicochemical Properties
400500 -- Photochemistry
AMINO ACIDS
AROMATICS
AZAARENES
AZOLES
BEAMS
BENZOPYRENE
BOSONS
CARBOXYLIC ACIDS
CONDENSED AROMATICS
CRYOGENICS
DESORPTION
DYNAMIC MASS SPECTROMETERS
ELEMENTARY PARTICLES
ELEMENTS
FILMS
GALLIUM
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
IMAGES
INDIUM
INDOLES
ION BEAMS
IONIZATION
LASERS
MASS SPECTROMETERS
MASS SPECTROSCOPY
MASSLESS PARTICLES
MEASURING INSTRUMENTS
METALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOIONIZATION
PHOTONS
PYRROLES
SORPTION
SPECTROMETERS
SPECTROSCOPY
SPUTTERING
THIN FILMS
TIME-OF-FLIGHT MASS SPECTROMETERS
TIME-OF-FLIGHT SPECTROMETERS
TRYPTOPHAN