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 m icroscopy (SNOM) architecture. In a first stage, the expected transmis sion behaviour of a sharp silicon probe is investigated by calculating the complete electric-field distribution both inside and outside a si licon tip facing a sample. Experimental applications using near-infrar ed radiation (lambda = 1.06 mu m) are then proposed. In particular, co mpact 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 t han or equal to 100 nm), topography artifacts were clearly evidenced. The resulting highly resolved images of nanostructures are to be attri buted to some interference effects occurring between the illuminated p robe and the sample. (C) 1998 Elsevier Science B.V. All rights reserve d.