What is the difference between silicon and silicon nitride cantilevers and tips?
Silicon and silicon nitride (Si3N4) are the two materials most often used in fabrication of cantilever assemblies. Each has its advantages and disadvantages. Silicon nitride tips usually have larger radii (on the order of tens of nanometers) and lower aspect ratios, which may degrade lateral resolution and ability to image steep features. Silicon tips can be manufactured to have radii of curvature of less than 10 nanometers and aspect ratios as high as 1:5. The price for this is that silicon tips wear down more quickly and break more easily. Another problem associated with silicon nitride cantilevers is that they tend to have residual stress that may result in the twist of a cantilever if its thickness is greater than 1 micron. For this reason, non-contact and tapping mode cantilevers are usually made of silicon.
