Minimized blurring in stencil lithography using a compliant membrane

This work reports on advanced stencil lithography using compliant membranes. Compliant membranes are mechanically decoupled from a rigid silicon frame by means of four non planar cantilevers. Compliant membranes are protruding parts which adapt to the surface independently in order to reduce the gap between a membrane and its substrate. FEM simulations show that compliant membranes can vertically deflect 40 mum which is a typical maximal gap. Microapertures were defined using UV lithography and nanoapertures, down to 200 nm in diameter, using FIB. A 100 nm thick aluminum layer was evaporated through compliant and non compliant membranes on a silicon wafer. Subsequent SEM characterizations have shown a smaller halo diameter around the structures patterned by compliant membranes.