Microfabrication of W band Folded Waveguide Slow Wave Structure using DRIE techonogy

The recent progress and the main fabrication process of manufacturing folded waveguide slow wave structures using deep reactive ion etching(DRIE) technology are briefly presented with an emphasis on fabrication of the etching mask and the prototypical W band serpentine trench etched in Si using DRIE.Feasibility studies of effects of fabrication parameters on the photoresist pattern are presented,especially on profile of the photoresist pattern.In the process of DRIE,the effects of platen power and the etch time sequence on the etch rate,etch profile are also studied in detail,so as to obtain the optimal fabrication parameters.With the optimal fabrication parameters,W band folded waveguide slow wave structure with the beam tunnel is fabricated.The W band serpentine trench is approximately 946 μm deep and its profile is 91°,and the beam tunnel is approximately 225 μm and its profile is 90°.