|
Nanonics produces systems that allows one to use the SPM probe for nano manipulation such as the application of defined forces and indentations on a surface. These systems allow for online combination of manipulation with SPM imaging and Raman characterisation of those manipulations themselves.
|
|
One of the major advantages of having an on-line AFM is the ability to use the probe for mechanical manipulation on a nano-metric level. On-line AFM can impose finely controlled and well-defined strain on a sample with high pressures. Since P=F/A, the smaller the tip, the higher the pressure. Since the area of the probe (A) is nano-metric the strain can reach up to megapascals of pressure |
|
40x40µm AFM image of silicon |
|
In the table below we see an AFM probe applying defined forces to a floating MEMs cantilever. At the same time the on-line Raman measures the shift in the silicon vibrational frequency and silicon strain at the point defined by the cross. We can see the shift in the Raman signal as a function of the applied stress. To date, no other system is capable of such a combination of on-line mechanical nano-metric manipulation and chemical characterization as well as the imposition of nano-electrical perturbations with Raman scattering.
 |
|
Nano-Raman measurements of stress in floating structures
|
On-line AFM allows defined forces to be imposed on MEMs cantilever, while the on-line Raman measures the shift in Si vibrational frequency. The image on the far left shows the AFM tip approaching a MEMS device. The central image shows a Raman spectrum. On the right we see the shift in the Raman signal as a function of the applied stress.
NanoIndentation
Another area at the forefront of modern research, is that of nanoindentation. Nanonics’ innovative technology, makes it now possible to measure the topography of a nanoindentation and then correlate in real time, on-line, the spectral intensity of the sample. Through the use of our specialized probes, nanoindentations are done together with Raman in order to “see” the changes in chemical bonding. For example, the following graph (below) depicts AFM and Raman mapping of a silicon indentation.
|
|
|
Raman spectrum as a function of the local stress.
Blue line shows the effects on the Raman shift due to increasing
the local pressure imposed by the on-line AFM probe on the MEMs
cantilever. Pink line shows the effect of reducing the probe pressure
on the MEMs cantilever. A hysterisis type effect is observed
.
|
|
|
AFM image of nano-indentation
on silicon sample |
|
