Direct growth of nanostructures by deposition through an Si3N4 shadow mask

We propose a method for the simultaneous fabrication of a multitude of identical nanodots. Without any further lithographic procedures, structures in the regime of 100 nm and below can be directly prepared by vapour deposition while partly shadowing the substrate with a free standing stencil mask, - here an Si3N4 membrane with an array of small holes. With such a mask very uniform dots of chromium have been grown on germanium substrates. They have the shape of truncated cones with a bottom diameter of about 550 nm. A reduction in size was achieved by applying a mask with reduced hole diameters ranging up to 300 nm. Due to a shift of the mask during evaporation, we obtained lines suggesting that even custom designed structures will be possible, if the lateral movement of the mask is precisely controlled. (C) 1999 Elsevier Science B.V. All rights reserved.