Fabrication of the Isolated Nano-beams in the Normal (111) Si Wafers with KOH Etching

Described in this paper is a novel method to fabricate the isolated nano-beams in the normal (111) Si wafers. The cantilever and the double clamped beams with nano thickness are anchored through the metal wires, which are isolated to the substrate electrically. The thickness of the beams is determined by dry etching. The beams are released by KOH etching. As the bottom of the beams is (111) plane, which is etched very slowly in KOH etching, the etching is self-ended after the beams are released. The gaps between the beams and the substrates are determined by RIE etching before releasing, due to the fact that the surfaces of the substrates are also (111) planes. When the gaps between the beams and the substrates are large enough, the nano beams can be released without the special treatment. The surface roughness of (111) wafer is also discussed in the paper