Testing of a Micro Faraday Cup Array for Ion Detection in SIMS

Abstract

A micro-Faraday array detector (row of miniature 32 thin film strip electrodes wire bonded to an on-chip integrated capacitance transimpedance amplifier) was tested for use in a multiple collector secondary ion mass spectrometry. The detector was mounted on a standard IMS3f SIMS instrument in place of a microchannel plate. The measurements were performed by using a silicon sample bombarded by either or Cs⁺ primary ions with or without D₂O flooding and detecting secondary ions of Si^±, SiH^±, O^-, SiD⁻, OD⁻. A parallel detection of near masses of ²⁹Si and ²⁸SiH or ¹⁸O and ¹⁶OD was demonstrated at a sensitivity level ∼230 counts/s.

Keywords:

• Capacitance transimpedance amplifier
• Faraday cup
• Ion detection
• SIMS

Acknowledgments

We are thankful to Dr. Klaus Franzreb from ASU for help with the IMS3f alignment and for valuable comments to this work. This work was supported by NASA Grant NAG5–11899 and by the grant of the Ministry of Education, Youth, and Sports of the Czech Republic ME894.