Research interests in our research group

The research activities of the group can be divided into three main areas:

  1. fundamental studies of ion–matter interactions
  2. detector, data acquisition and analysis software development and
  3. application of ion beam techniques for materials and thin film studies.

The key infrastructure of the group is the 1.7 MV Pelletron accelerator and all the research equipment in its beamlines. In Nanoscience Center (NSC) clean room the group is a very active user of a helium ion microscope (HIM) and a versatile atomic layer deposition (ALD) tool. The group is an active link between the two research infrastructures Accelerator Laboratory and Nanoscience Center. In addition, the group focuses strongly in detector development related to the ion beam techniques. The group is also tightly linked to the other thin film research groups and industry in Finland.

Selected publications

Simulations on time-of-flight ERDA spectrometer performance
Jaakko Julin, Kai Arstila, Timo Sajavaara
Rev. Sci. Instrum. 87 (2016) 083309

The detector, data acquisition, and analysis software development combines experiments and simulations to yield a better understanding and higher performance of the ion beam analysis methods.

The α and γ plasma modes in plasma-enhanced atomic layer deposition with O2–N2 capacitive discharges.
M. Napari, O. Tarvainen, S. Kinnunen, K. Arstila, J Julin, Ø.S. Fjellvåg, K Weibye, O. Nilsen, T. Sajavaara
Journal of Physics D: Applied Physics 50 (2017) 095201

Two distinguishable plasma modes in the O2–N2 radio frequency capacitively coupled plasma (CCP) used in remote plasma-enhanced atomic layer deposition (PEALD) were observed. The growth rate, thickness uniformity, elemental composition, and crystallinity of the films were found to correlate with the deposition mode. In remote CCP operations the transition to the γ mode can result in a parasitic discharge leading to uncontrollable film growth and thus limit the operation parameters of the capacitive discharge in the PEALD applications.

Broadband Ultrahigh-Resolution Spectroscopy of Particle-Induced X Rays: Extending the Limits of Nondestructive Analysis
M. R. J. Palosaari, M. Käyhkö, K. M. Kinnunen, M. Laitinen, J. Julin, J. Malm, T. Sajavaara, W. B. Doriese, J. Fowler, C. Reintsema, D. Swetz, D. Schmidt, J. N. Ullom, I. J. Maasilta
Phys. Rev. Applied 6 (2016) 024002

A paper reporting the capabilities of high-resolution PIXE when multi-pixel transition edge sensor (TES) is used as an energy detector.