AIF: Focused Ion Beam

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Analytical Instrumentation Facility

Secondary Electron image of FIB tem sample

STEM image Multi Quantum well image in STEM

FIB image of cut in metal

FIB image of cut through semiconductor device

FIB of TEM specimen preparation

PHI TRIFT I Time-of-Flight Secondary Ion Mass Spectrometer (TOF-SIMS)

Location: 306 EGRC

Contact: Fred Stevie

The Physical Electronics Instruments (PHI) TRIFT I Time-of-Flight Secondary Ion Mass Spectrometer (TOF-SIMS) uses a pulsed and focused ion source and time-of-flight analyzer to obtain high spatial and mass resolution data from a specimen surface. Because of its high mass resolution and range, this system is particularly good at examining organic materials. Most data are collected in a "static" mode with minimal damage to the outer surface. A second ion source is used for higher rate sputtering.

The laboratory is equipped with a variety of ways to cut, polish, and clean specimens prior to analysis or experiment. Handling of specimens for surface analysis and vacuum work involves several considerations, and users not familiar with these needs and requirements should contact AIF staff or consult the ASTM E-1078 Standard Guide for Sample Handling in Auger Electron Spectroscopy, X-ray Photoelectron Spectroscopy, and Secondary Ion Mass Spectrometry .

Specifications
Mass Range	0-10,000 amu
Mass Resolution	9000 or greater
Spatial Resolution	0.12 µm
Ion Gun	15kV (high mass resolution) and 25kv (high spatial resolution) Ga
Features	Focused Ga ion beam (0.12 µm - 2.0 µm, 1.5 nA) Beam raster to allow data collection and imaging over a 1.2 X 1.2 mm area Ion beam induced secondary electron imaging of specimen Elementally specific mapping capability CCD camera imaging of sample to allow location of region to be analyzed Charge compensation source - pulsed low energy electron gun Cold stage with capability for introducing frozen specimens.

Time-of-Flight Analyzer
Mass Analyzer	TRIFT I energy compensating TOF mass spectrometer using three spherical electrostatic analyzers. Spectrometer has two meter normal flight path.
Detector Optics	Dual microchannel plates with phosphor screen. Video camera for real-time viewing of secondary ions.
Detector Electronics	1024-stop Time-to-Digital converter with 138 ps minimum time resolution. Includes a preamplifier and a proprietary constant fraction discriminator for enhanced precision in the measurement of the time-of-flight.
Analyzer Control Electronics	Bipolar supply for the focusing and steering elements. Extraction voltage pulsed to ground to provide a field free region at the sample during charge neutralization.
Detector Supply	Channel plate multiplier supply with post acceleration bias supply with integrated pulsing and bunching.
Beam Energy	0.5-25 keV; 15kV (high mass resolution) and 25 kV (high spatial resolution) nominal operating voltages.
Maximum Beam Current	> 1.5 nA
Minimum Beam Diameter	< 120 nm pulsed < 1 µm bunched
Pulse Width	< 700 ps bunched

Pulsed Charge Neutralizer and Electronic
Type	Low energy (< 20 eV) pulsed, focused electron gun. The sample voltage is at ground potential during charge compensation. Repetition rate, pulse duration, and sample pulsing under computer control.
Sample Handling
Stage	x and y axis manipulators with +/-2.5 cm translation
Sample Holder	Accepts 5 cm x 5 cm x 1 cm mounts with front referencing.
Sample Viewing
Viewing Optics	Microscope and color video camera.
Ion Beam Imaging	Ion-induced SED and secondary ion mapping.
Image Capture	Full color viewing and archiving of sample image.
Single Sample Cooling Stage
Cooling	Liquid nitrogen dewar on the sample stage.
Temperature	< -120°C
Specimen Holder	High thermal efficiency, 25-mm diameter.

Last updated February 21, 2006

Campus Box 7531 Room 318 EGRC, 2410 Campus Shore Dr., Raleigh NC 27695
Phone: (919) 515-2128 or 515-3841 Fax: (919) 515-6965