Production of High Aspect Ratio Single Holes in Semiconductors

M.-D. Gerngros, H. Foll, A. Cojocaru, and J. Carstensen Institute for Materials Science, Christian-Albrechts-University of Kiel, Kaiserstr. 2, D-24143 Kiel, Germany In many areas of research exists a need for single small holes with diameters from a few nm to several µm and large aspect ratios. Ex-isting technologies for that are complex and rather limited. It is shown by a simple proof of principle that suitable single holes or specific arrays of some single holes can be made by first etching a very large number of small and deep holes or pores into semicon-ductors like Si or InP by established electrochemical means, fol-lowed by masking the desired holes and filling all others with, e.g., a metal in a galvanic process. The potential and limitations of this technique are discussed in some detail.