Microfabrication of channels using an embedded mask in negative resist

A technique has been developed which allows the fabrication of channels within the body of multiple layers of negative, resist. Previously this was only possible in the positive resist system but with the transfer to negative resist, higher and more clearly defined channels are now possible. Thick negative resists are also easier to process than their positive counterparts, allowing multiple crossing channels. The physical structure of a full height W-band waveguide with an integrated E-plane filter has been fabricated with this technique. The fabrication procedure presented in this paper is quick, reproducible and easily implemented using standard photolithography equipment.