Surface modification

Surface modification/patterning of different materials. Besides the mechanical indentation mode using the AFM tip as a scalpel, it is possible to apply a voltage between the tip and the surface: an anodic material oxidation occurs depending on the voltage intensity. The oxidation is associated to a volume expansion of the material under the tip. This topographic contrast can be followed by a subsequent “development” into a chemical contrast.

An oxidation voltage of -9V is applied to the tip while the sample is grounded (6x6µm).	AFM probe is used to remove a portion of the film for measuring step hight.