Progress toward the fabrication of scanning near field optical probe: pattern definition by e-beam lithography

In this paper, we describe the progress towards the fabrication of a tip on top of a glass fiber. This paper focuses exclusively on the patterning which is defined on top of the flat end of the fiber, covered by a thin layer of chromium film that has been previously deposited. A special electron resist is used to transfer the circular pattern on the fiber. The resist consists of octavynilsilsexquioxane which is evaporated on top of the fiber by sublimation. The use of a dry resist enables us to deposit a uniform layer on a very small area which is a very difficult task to obtain with the use of wet resists, which require spinning techniques, that should also be very difficult to use in the specific case of the end of an optical fiber. After development, the pattern is transferred to the chromium film underneath by wet etching. This procedure has been optimized in order to preserve the pattern resolution obtained by means of electron beam lithography. The chromium film is the mask which will be used to perform the etching of the fiber. (C) 2001 Elsevier Science B.V. All rights reserved.