SIMS2015 Session TPS-TuM: Plenary Session

Much progress has been made in the development of the secondary ion mass spectrometry (SIMS) technique, and SIMS is now one of most powerful and useful techniques for surface analysis. By using various primary ion beams and mass spectrometers, elemental, as well as chemical analysis can be realized. The SIMS technique is usually classified into dynamic-SIMS and static-SIMS. At present, elemental analysis for inorganic materials is mostly carried out with the dynamic-SIMS technique, and chemical or molecular analysis is carried out with static SIMS, in which the time-of-flight (TOF) and small cluster ion beams techniques are commonly employed.

Recently, large cluster ion beams have been developed and commercialized for surface analysis techniques, such as SIMS and X-ray photoelectron spectroscopy (XPS). The surface damage of organic materials, sputtered with such beams, is significantly reduced. Molecular depth profiling and three dimensional (3D) analyses have been demonstrated for organic devices and biological materials. However, the large cluster ion beams are hard to use as a primary ion beam in SIMS, because of problems linked to beam diameter, mass resolution and beam current. The latest SIMS equipment utilizes mass spectrometers without pulsing primary ions¹⁾, and a finely focused large cluster ion gun has been developed for this purpose2⁾. Because the use of large cluster ion beams overcomes the static limit of the ion dose, the dynamic SIMS was newly developed to analyze organic materials.

Higher mass and spatial resolution, sensitivity and lower detection limits are always required for expanding the application fields of the SIMS technique. Increasing the secondary ion yields is one of the “grand challenges” in the SIMS area, and reactive cluster, massive cluster and liquid droplet ions have been extensively studied quite recently.

Furthermore, SIMS under ambient pressure has been developed using swift heavy ions³⁾. This technique, called MeV-SIMS, enables measurements of volatile molecules, liquids and solid–liquid interfaces. These materials, which are technological and practically very important, are still undeveloped fields in the area of SIMS analysis.

The latest developments of SIMS system will be overviewed and discussed with possible application fields.

Reference

[1] ToF-SIMS: Materials Analysis by Mass Spectrometry–2nd Edn, J. Vickerman and D. Briggs, IM Pub.

[2] J. Matsuo, S. Torii, K. Yamauchi, K. Wakamoto, M. Kusakari, S. Nakagawa, M. Fujii, T. Aoki and T. Seki Appl. Phys. Exp. 7, 056602 (2014)

[3] J. Matsuo, S. Ninomiya, H. Yamada, K. Ichiki, Y. Wakamatsu, M. Hada, T. Seki and T. Aoki, Surf. And Inter. Anal. 42, 1612 (2010)