Analysis of the aperture formation mechanism in the fabrication process of nano-aperture arrays

The fabrication of nano-aperture arrays has attracted much interest for its potential application in near-field optical recording, one of the most probable candidates for high-density storage devices. A parallel-processing technique based on nano-aperture arrays has been investigated in order to achieve fast scan rate. In this work, the fabrication process of nano-aperture arrays and the analysis on the aperture opening mechanism will be presented. A series of oxide pyramid arrays have been fabricated by generating inverted pyramid array followed by stress-dependent oxidation on inner surfaces and backside Si etching. Nano-apertures have been opened at the apexes of pyramids by diluted HF solution. The relation between aperture diameters and etch time showed good linearity with proper aperture opening rate. The variation of opening rate upon HF concentration was examined and measured to be 23 nm/min for 50:1 HF solution. Investigations on the parameters determining aperture-opening rate will be discussed. 2004 Elsevier B.V. All rights reserved.