High-current implanter with keV Ions

For ion implantation and ion beam analysis with keV ions, an accelerator platform is available that can produce ion beams up to 350 kV from a substantial fraction of all elements in the periodic table.

For ion implantations as well as ion beam analysis methods using keV ions, the Tandem laboratory features a Danfysik 1090 accelerator platform. The machine is equipped with a highly versatile ion source that allows us to produce ion beams from almost all elements of the periodic table for a wide range of applications. The ions are accelerated with up to 350 kV and steered into one of three beamlines for different applications.

• Ion Implantations. The first beamline is dedicated to implantations and irradiations. Beam currents of up to a few mA enable high-dose implantations even on large targets.
• ToF-MEIS System. The second beamline consists of our unique Time-of-Flight Medium-Energy Ion Scattering (ToF-MEIS) system, used for high-resolution depth profiling and crystallography of thin films.
• Multifunctional Scattering Chamber. The third beamline extends to a multipurpose scattering chamber. Most prominently, the set-up allows to depth-profile ¹¹B and ¹⁸O using nuclear reactions.

A wide range of elements is available for ion implantation at energies up to 350 keV.

Ion implantation is routinely used by both academic researchers and industry for numerous applications, for example in microchip manufacturing.

The Tandem Laboratory’s implantation facility is the only academically operated and openly accessible one of its kind in Sweden. Researchers and companies without their own implanter can apply for beam time.

The target chamber is accessed through a cleanroom environment to ensure ultra-clean surfaces during sample preparation and mounting.

Wide range of implantation elements

The Tandem Laboratory’s ion implanter provides a broad selection of available source materials to meet requests for various ion species. Examples of available ions include those commonly used in semiconductor dopants (B, BF₂, Al, P, As, and others), various metals (e.g. Fe, W), as well as light and heavy noble gases.

Adjustable irradiation flux, dose, and charge state

We can adjust particle flux and dose, and deliver either singly or doubly charged ions. The latter enables ion energies of up to 700 keV at maximum acceleration voltage. Due to the high achievable beam current (up to several mA), implantation at very high doses is possible. See the publication below for an example.

The Time-of-Flight Medium-Energy Ion Scattering (ToF-MEIS) system is a developed at the Tandem Laboratory using pulsed keV ion beams enabling in-situ studies of thin layers.

Designed by researchers at the Tandem Laboratory, the Time-of-flight medium-energy ion scattering (ToF-MEIS) system combines pulsed keV ion beams with advanced detection technology.

This unique equipment has been developed for non-destructive, high-depth-resolution analysis of the chemical composition and crystallographic structure of thin layers.

In this beamline, the keV ion beam from the implantation platform is divided into short pulses approximately 1 nanosecond in duration. This allows for high-resolution energy measurements, beneficial both for fundamental research on ion-solid interactions and for depth-resolved studies of materials at the nanometre scale.

Angle-resolved measurements

The scattering chamber features two detectors. The first detector is movable and can be positioned at any scattering angle for measurements in different geometries (backscattering, forward scattering, and transmission geometry). Its large area enables short measurement times as well as angle-resolved measurements and imaging of crystal structures.

Sub-nanometre depth resolution

The second detector is fixed at a longer distance from the sample, providing improved time resolution corresponding to a depth resolution of below one nanometre. The detector type used is sensitive sensitive not only to ions but also capable of detecting neutral atoms, electrons, and photons.

The ToF-MEIS system is complemented by a sample preparation chamber allowing fabrication of thin films and preparation of surfaces for in-situ studies ofof surface and near-surface phenomena.

The multifunctional scattering chamber for sub-MeV ion beam analysis can, among other applications, be used for depth profiling of the isotopes ¹¹B and ¹⁸O via nuclear reactions.

This beamline is dedicated to sub-MeV ion beam analysis. Multiple detectors allow for near-surface materials characterisation with high resolution.

Isotope-selective studies of materials diffusion

A unique feature of this set-up is the usage of two nuclear resonances of keV protons: at 151 keV with ¹⁸O and at 163 keV with ¹¹B. By detecting the resulting alpha particles, these isotopes can be quantified depth-resolved permitting isotope-selective studies of materials diffusion. This capability has also been used to quantify boron in transition-metal borides, which are technologically relevant for coatings or as friction materials.

Other techniques available are high-solution backscattering spectrometry, also in combination with channelling, and low-energy PIXE for detection of elements as light as carbon.