Fabrication of grids and collimators using SU-8 as a mold

The fabrication process of ultradeep (aspect ratio greater than 25) microchannels in SU-8 photoresist using deep X-ray lithography is described. We have demonstrated that with single-layer coatings, 1-mm-deep trenches in continuous resist layer can be achieved reproducibly. Microchannels with vertical walls and with walls tilted up to 20° from vertical have been fabricated. Electroforming of the channels resulted in metal grids and collimators for various applications. A thickness enhancement method for fabrication of very tall structures is also described.