Capabilities

Get an idea of what we could do for you.
We offer a wide range of capabilities, e.g., in analytics and metrology:
From AFM and SEM to fluorescence microscopy, ellipsometry and profilometry, all in one place.

The following articles give you an idea what some of our instruments can be used for. Together we can investigate the possibilities these instruments might give you.


Examples

Surface treatment and surface control – determination of surface topography and roughness (AFM), transmissivity (spectrometer), morphology (SEM, profilometer, interference microscope) and electric conductivity (wafer probe station).

Excimer laser processing of an organic layer on a membrane fiber structure.
Micro structuring of organics covered membranes
Excimer laser treatment
was applied to selectively remove the organic molecule cladding of membranes. The aim was to remove the cladding, leaving the core undamaged. As a first task the border layer between membrane and organic layer was examined. Optical dark field microscopy served to determine the boundary. After application of the excimer laser, scanning electron microscopy was used to characterize the ablation holes that the laser created. The ablation rate for membrane material varied by a factor of 10000 compared to that of the organic cover layer. This way it became possible to accurately ablate an ultrathin organic film with a depth resolution of less than 20 nm. The image shows an organic layer that was cut perpendicular to the fiber axis. In addition, excimer laser ablation was used to remove a large part of the fiber (right-hand-side), showing the structure of the cladding. That way, excimer laser ablation can be used as an alternative to microtomography using a field ion beam (FIB) apparatus.



Scratch on a CD, imaged via AFM.

Atomic force microscopy (AFM) is a versatile microscopy technique to image with uprecedented resolution. As long as the samples (max. sample sizes 2 cm x 2 cm x 0.5 cm) are reasonably flat (heights differences between nanometers and 5 micrometers), topography and roughness can be obtained on scales between 10 nm x 10 nm and 100 micrometer x 100 micrometer. Surfaces of bulk materials as well as thin films, nanostructures, nanoparticles, metals as well as insulating specimen such as polymers, ceramics, and minerals are examinable with little or no sample preparation. Measurements can be done in air and in non-corrosive liquids such as water or ethanol, and for temperatures between room temperature and 250 °C. That way biological samples such as living cells or biomolecules can be imaged in their natural environment, and materials which undergo phase transitions.

But AFM goes one step further than conventional microscopy techniques: on a nanometerscale electrical, magnetic, or mechanical and chemical properties such as the elasticity and the "stickiness" of the specimen can be mapped. The primary uses for an AFM are therefore
  • the three-dimensional visualization of the surface of the samples including cracks, defects, contaminations
  • spatial metrology of surface features within nanometer sized dimensions
  • mapping of the physical and chemical sample properties


Typical measurement with a surface profilometer. Measured is the width and hight of a structure in silicone.
Resolve the topography of a surface on a 100 mm x 100 mm large scale for a quik overview. 

The profilometer is typically used to measure step heights or depths of holes by scanning a tip over the surface while recording the height. In the example on the right the width and height of a structure in silicone such as channels for microfluidic was determined. 
It depends on the sharpness of the tip how accurate you can measure a step on the surface. Our instrument uses a tip of 12.5 µm in diameter. As the tip is actually pressed on the surface the surface should have a certain hardness so the tip does not penetrate it. The applied force can be adjusted between 1 mg and 15 mg.
Apart from the typical application as seen in the graph you can do roughness studies, surface quality and defect review and curvature measurements.






 
 Fabricated microchannels  under an Interference microscope.
The Interference microscope gives information on the homogeneity of the surface and, via interference it is possible to obtain the thickness of thin layers on the surface. The image shows microchannels as they were fabricated via wet etching. In this case the interference microscope allows to get a fast overview of the resulting channels and their angle with respect to the surface.
The principle of the interference microscope: light that passes through or is reflected from the object interferes with light that passes through or is reflected from a different region of the specimen plane or is reflected from a comparison (reference) surface. Differences in optical path introduced by various parts of the object can be seen as variations in intensity or color. Interference patterns as a function of table movement are recalculated into a topographic pattern of the structured substrate under investigation. That way height information with sub-Ångstrom precision becomes available.




Gecko Feet as seen under the SEM.
Investigate smaller structures by Scanning Electron Microscopy (SEM). The instrument is a Hitachi S-4800 and allows to resolve structures down to approx. 1 nm. The magnification is adjusted between 30x and 100000x, allowing analyses from millimeter to nanometer scale. The SEM features two detectors, a Back Scattered Electron detector (BSE) and a Secondary Electron detector (SE) and it allows to image the size, shape and texture of three dimensional objects.