ABSTRACT
Evanescent waves can be obtained by Total Internal Reflection (TIR) at semi conductor (InP) surfaces and explored by silicon tips in the mesoscopic range (100 nm). It is shown that important perturbation arise in the converted light collection due to the contamination layer on the surface; such a phenomenon leads to consequences in the scanning optical images. Using low compliance cantilevers we measure the active forces at different moisture levels and for distances in the range of 100 nm. The contribution of the Van der Waals forces is discussed comparatively to the electrostatic ones arising from the surface states of the InP material. It is shown that optical tunnel effect could be a very sensitive tool for the qualification of the contamination layer.
