A dry-release method based on polymer columns for microstructure fabrication

A fabrication process that eliminates the adhesion of surface-micromachined suspended mechanical structures to the underlying substrate during a sacrificial-etch release is presented. The method is based on the construction of a periodic array of polymer columns or rubber feet that stiffen the structure during the sacrificial etch. Flat polycrystalline silicon plates measuring 3000*3000*1- mu m suspended 1 mu m above the substrate are easily fabricated by this method. This process has applications in the fabrication of micromachined plates used in devices such as accelerometers and pressure sensors.<
>