Study On Fabrication Technology Of Nano-resonator Structure

Nano-beam is the fundamental structure of the device used in NEMS. In this paper,several methods to fabricate the single-crystalline silicon nano-beams are presentedwhich take advantage of the characteristic of material and process in MEMStechnology.Nano beams whose thickness is less than 100nm can be fabricated in (100) SOIsilicon wafers by thinning the top layer silicon with thermal oxidation. Theconsistency and the repeatability of the method are good because the thermaloxidation has good precision and repeatability. Also, a novel method to fabricatenano-wire whose cross section is right-angled triangle is presented.The cantilever and the double clamped beams whose thickness is lower than 100nmcan be fabricated in (111) wafers by combining the anisotropic wet etching with thedry etching. The method is low cost as the expensive SOI wafers are not needed. Asthe bottom surfaces of the nano-beams are (111) plane, the etching is self-stoppedafter the nano-beams are formed. Therefore, the thickness of the beams can becontrolled accurately.The two clamped beams whose width is less than 100nm can be fabricated in (110)SOI silicon wafers by the anisotropic wet etching. The side faces of the beam are (111)plane and the etch rate is very slow in KOH or TMAH. Therefore, the width of thebeam can be controlled.The frequencies and Q factors of the resonator are measured with opticalinterferometry.