Patterning of silicon by indentation and chemical etching

An array of features on Si (100) is fabricated by a new maskless pattering process involving a combination of indentation and anisotropic wet chemical etching. Indentation is carried out in order to induce transformation to the high-pressure phases, Si III and Si XII, before etching in a KOH solution. The pressure-induced phases are found to be highly resistant to etching in the KOH solution, with an etch rate more than an order of magnitude slower than that of Si (100). The possibility of exploiting this mechanism for a maskless nanoscale patterning process in Si using indentation is discussed.