Shape and size control of regularly arrayed nanodots fabricated using ultrathin alumina masks

We report an approach to fabricate highly ordered semiconductor and metal nanoparticle arrays with controllable shapes and sizes, including nanometer-sized disks, hemispheres, hemiellipsoids, and conics. The nanoparticle arrays are fabricated on Si and Si/SiO2 substrates using ultrathin alumina masks (UTAMs) as evaporation masks. The shapes and the sizes of the nanoparticles are adjusted by changing the aspect ratio of the apertures of the UTAMs, and the amount of material deposited through the UTAMs. Highly ordered semiconductor nanoparticle arrays with particle sizes down to about 20 nm have also been fabricated.