Fabrication Process for Surface Micromachine with Small Sticking Problem by Use of Image Reversal Resist as Sacrificial Layer

Abstract

A new process is developed for a surface micromachine fabrication with a small sticking problem. Electroplated Ni film is used as maicromachine material and a resist for the image reversal process is used as a sacrificial layer. The processes for the image reversal are carried out before making movable structures. The resist is developed after making movable structures. Movable structures are fixed by small resist columns when the development of the sacrificial layer resist is finished. Finally, the small columns are removed by O₂ plasma. Cantilevers with long and wide beam are fabricated by the new process. The cantilever with 1000μm length and 100μm width beam can be fabricated without the sticking problem. The mechanical properties of the electroplated Ni film are examined. It is found that the mechanical properties of the electroplated Ni film is almost same as those of a bulk Ni.