Direct writing of Si island arrays by focused ion beam milling

We report on a new technique for the fast fabrication of well defined arrays of Si islands by means of a stigmated Ga+ focused ion beam without masks, resists or etching. Stigmating and defocusing the ion beam resulted in the direct formation of Si islands of different shape and size. The ordering of the island arrays was determined by the pattern of the beam scanning, and in this way nanometre-sized Si island arrays with hexagonal symmetry were accordingly produced. The effects of beam spot distortion and broadening on the milled structure are also examined by scanning electron microscopy imaging. With this technique, not only is the fabrication time shorter, but also the arrangement of the island arrays is possibly controllable.