3D imprint lithography using Si/sub x/N/sub y/ molds

Three-dimensional patterning reduces more complicated alignment steps in the fabrication of micro and nano-scale structures. Multiple lithography processes with interlevel alignment or single lithography with multi layer resist is essential for three dimensional patterning. A number of 3D structures have found immediate applications in a range of microelectronic systems such. as micro-optics, micro-electromechanical systems, and in monolithic microwave integrated circuits. We have previously demonstrated that imprint at low temperatures (well below the glass transition of the resist) is possible for a number of structures using silicon nitride (Si/sub x/N/sub y/) molds. A low temperature process is important for pattering substrates or polymer-based materials that are intolerant of high temperatures. The advantages of using Si/sub x/N/sub y/ for mold making are the capability of forming reliable nanoscale structures and its surface properties that allows imprint without sticking. In this work we will present pattering results for three-dimensional structures using nanoimprint lithography with Si/sub x/N/sub y/ molds. The mold material consists of a 1/spl mu/m thick low stress Si/sub x/N/sub y/ layer deposited by low-pressure chemical vapour deposition (LPCVD) on to a silicon substrate. Patterning of the Si/sub x/N/sub y/ was performed using electron beam lithography at 50keV into ma-N 24033 negative tone resist.