Photon tunneling from semiconductor surfaces to atomic force microscopy probes

Abstract

Atomic force microscopy probes are currently obtained from silicon microelectronic technology; very sharp tips can be made by chemical vapor deposition, by etching or by focussed ion beam machining techniques. We have used tips such as photon collectors in order to convert the evanescent IR light waves emitted from a semiconductor surface when it is internally illuminated at an incidence angle that is larger than the critical angle of reflection (photon scanning tunneling microscopy (PSTM)). For SiN tips it has been shown that the intensity of the transmitted light varies with the distance from the surface and the angle in agreement with the predictions of Maxwell's laws, according to a computer simulation. In this work a monitoring of the Si tip PSTM performances is presented comparatively and discussed in the particular case of semiconductor surfaces and IR YAG laser illumination (1.06 μm and 1.32 μm).