Modern Approaches in Ion Beam Analysis - Challenges and ongoing Developments


Modern Approaches in Ion Beam Analysis - Challenges and ongoing Developments

Heller, R.

The general trend in technology and science to create, process and analyze small structures on a nm scale or even on an atomic scale leads to new challenges in modern ion beam analysis (IBA). This is accompanied by higher demands on the lateral resolution as well as by the demand on high precision determination of elemental compositions on an atomic depth scale. Further the complexity of processing materials in micro and nano electronics is increasing continuously. Thus elemental analysis is no longer limited to the determination of a few particular atomic species and a division of measurement tasks into „light element in a heavy matrix“ or vise versa becomes obsolete in this way. 

Thinner but more complex layer structures are closely related to an increased sensitivity on external impacts. Even the transport of a sample to the place of analysis under ambient conditions can lead to unwanted (chemical) modifications at the surface. Thus IBA under in-situ conditions has developed into an established method within recent years. Furthermore in technological developments not only the state of a system after processing but the process itself may be of particular interest. “Online” IBA under process conditions is thus more and more desired.

Analysis methods of classical IBA like RBS (Rutherford Backscattering Spectrometry), ERD (Elastic Recoil Detection Analysis), PIXE (Particle Induced X-Ray Emission) or PIGE (Particle Induced Gamma Emission), either applied as broad beam or in terms of a micro probe, can therefore rapidly reach their limits. Even the use of modern magnetic spectrometers with depth resolution of a few nano-meters may in particular situations not be sufficient.

Searching for approaches to all these modern measurement tasks often brings IBA to the physical limits and thus complicates quantitative analysis. This for instance may manifest in energy depended charge fractions of the projectile, deviations from classical Rutherford cross-sections, the modification of the sample by the probing beam, etc. All these effects have to be carefully taken into consideration when interpreting analysis results.

The present contribution will give an overview on the demands and difficulties resulting from the described demands on modern IBA. Ongoing development of new IBA techniques and approaches at the Ion Beam Center at HZDR will be presented and discussed. Those are covering

  • the realization of IBA within a Helium ion microscope,
  • the unification of different IBA techniques in complex experimental chambers including in-situ capabilities,
  • the increase of efficiency of lateral resolved PIXE measurements,
  • the controlled implantation of single ions into surfaces with nm precision, as well as
  • concepts for a new low-energy ion laboratory.

Keywords: Ion Beam Analysis; IBA; TBS; ERD; PIXE; lateral resolved IBA

Related publications

  • Invited lecture (Conferences)
    50th Zakopane School of Physics, 18.-23.05.2015, Zakopane, Polen

Permalink: https://www.hzdr.de/publications/Publ-23079
Publ.-Id: 23079