We aim to fabricate stencils with apertures in the sub-micron range <500nm for shadow mask deposition. The apertures are fabricated with focused ion beams that allow rapid replication and sub-100nm resolution. Using the stencil, the resolution and structures achieved with the FIB can be transferred and replicated just by a single evaporation without the use of sensitive polymers. For this work we use thin membranes of LS SiN, 100-200 nm-thick with a thin metallic layer to avoid charging during milling. Possible applications for these nanostencils include nanoelectronics, dynamic stencil deposition and patterning on non-Si substrates.