Focused Ion Beam

We provide highest flexibility regarding material and depth

With our dual-beam systems at Fraunhofer IISB, consisting of a scanning electron microscope (SEM) and a focused ion beam, we can image and process any material simultaneously and with nanometer precision. Sample preparation with the FIB can be carried out at various stages of device manufacturing, for example to detect growth defects or for later examination of faulty devices, e.g. when switching processes do not work. This enables defect analysis in assembled systems as well as the visualization of doping and damage processes of implanted devices, cross-section analysis in a layers or local process control on wafers.

In combination with versatile lift-out systems, any geometries can be lifted out of the material with the utmost precision and transferred to other systems (TEM, X-ray tomography, etc.) for further analysis. A wide variety of integrated detectors such as STEM, EDX or EBSD enable direct material analysis in the system, in dimensions ranging from nanometers to several hundred micrometers.

At Fraunhofer IISB we work with two FIBs, a plasma FIB and a gallium FIB. The synergy of the different ion systems makes it possible to cover the entire range of application fields. The plasma FIB system with xenon ions allows us to process large areas and depths of up to several hundred micrometers in a very short time, whereas the gallium FIB system can be employed for preparations of TEM lamellae or needles, so-called pillars, with a high accuracy of < 90 nm thickness. With suitable software, we create 3D tomographies and 3D models from cross-sections, which make microstructures, porosity changes or local defects such as growth defects in crystals visible. The various detectors can also be used here (e.g. 3D-EDX or 3D-EBSD).

Our decade-long experience with a wide variety of materials opens up a long list of preparation and analysis possibilities from semiconductor materials to polymers, glasses, diamonds, bones, metals, crystals, ceramics, ...

The fast, cheap and cleanroom compatible preparation method, patented by Fraunhofer IISB

The ion beam scatters at the entrance of each cut in the form of a Gaussian profile, creating a rounded incision that is unsuitable for further investigations. Without a protective or buffer layer, this would mean that the upper layers cannot be analyzed as they have been removed imprecisely. Therefore, it is currently common practice to apply a platinum layer to the sample before processing using FIB in order to compensate for the edge rounding. However, this process takes around 1 hour and is therefore relatively time-consuming. In addition, wafers on which platinum has been deposited cannot be returned to the clean room and are considered contaminated.

The Flying Cube process developed and patented at Fraunhofer IISB solves these problems: The Flying Cube is a piece of silicon that is stabilized with a needle and floats above the sample. As a result, the FIB first cuts through the Si cube without depositing impurities on the sample surface. A platinum layer is no longer necessary. This Si cube is flexible and quick to use, the process takes around 30 minutes, or significantly less depending on the routine. In addition, the Si cube can be reused up to 20 times and is therefore much more cost-effective and, most importantly, cleanroom compatible.