Transmission scanning near-field optical microscopy with uncoated silicon tips

In this paper we report on the implementation of an uncoated silicon (Si) cantilever probe into a transmission scanning near-field optical microscopy (SNOM) architecture. In a first stage, the expected transmission behaviour of a sharp silicon probe is investigated by calculating the complete electric-field distribution both inside and outside a silicon tip facing a sample. Experimental applications using near-infrared radiation (lambda = 1.06 mu m) are then proposed. In particular, compact disc features (Delta x less than or equal to 1 mu m) were imaged successfully with our setup (lateral resolution: better than 250 nm). Furthermore, when dealing with finer sample structures(Delta x less than or equal to 100 nm), topography artifacts were clearly evidenced. The resulting highly resolved images of nanostructures are to be attributed to some interference effects occurring between the illuminated probe and the sample. (C) 1998 Elsevier Science B.V. All rights reserved.