Secondary Ion Mass Spectrometer at Arizona State University

Arizona State University

http://sims.asu.edu

Contact Information

Richard Hervig

480-727-7282

sims@asu.edu

Tempe

Instrument Type

Cameca Instruments (Ametek) ims 6f

Dynamic SIMS instruments use an energetic (5-15 keV) primary beam of ions (O, Ar, Cs are most common). When the primary beam is directed at a sample, the collisions result in the ejection of atoms. Some of the "sputtered" atoms are ionized in the process and this secondary beam is accelerated into a mass spectrometer (magnetic sector or quadrupole) for analysis. The instruments are commercially available largely because of their critical role in quality control/quality assurance in semiconductor fabrication plants, where a tool that can determine changes in chemistry with depth is essential. Small-geometry SIMS as described here are used by geochemists in the fields described below. Some "large geometry" dynamic SIMS instruments are used in government agencies for nuclear forensics (treaty verification and nuclear non-proliferation) and by researchers interested in U-Pb dating and several applications in microanalyses for stable isotopes.

SIMS, Secondary ion mass spectroscopy, or Dynamic SIMS

Application:

Applications include:

Identification of phases
Composition (elemental) of phases
Elemental mapping, compositional zoning
Trace element analysis
Surface chemistry (sorption, catalysis)
Depth profiling (chemical stratigraphy, nanometer scale)

Typical Use:

This small-geometry SIMS can quantitatively analyze small spots (a few to 40 µm diameter) for elements from hydrogen to uranium, with detection levels ranging from ~ng/g to µg/g, depending on the element. Microanalyses for isotope ratios can be obtained on several elements. Changes in chemistry on the scale of tens of nanometers can be determined in depth profiling mode. Most popular applications are microanalyses for H and other volatile elements (including D/H measurements), examination of intracrystal chemical zoning, and depth profiling thin films (e.g., semiconductors and retrieving diffusion coefficients).

Conditions for Use:

Submitted samples will be analyzed on a contract basis (i.e. lab personnel will do the work)
Visitors are invited to work in the lab to work with lab personnel
Visitors are invited to work in the lab to design and do the work yourself