Reverse nanostencil lithography using dual pattern transfer
Nanostencil lithography is considered a promising emerging nanopatterning method due to its simple process flow, low cost, little restriction on materials, and high compatibility with organic or biological surfaces. The principle of shadow mask deposition technique however has some drawbacks. First, as the pattern transfer occurs by deposition through apertures of a micromechanical stencil, empty zones inside material patterns cannot be achieved. A remedy presented for the >100um scale cannot be scaled down to nm scale. Second, when we produce a nanobridge structure for electronic or sensor devices, it is difficult to control the width of the bridge precisely because the nanoslit connecting two large openings in the stencil is composed of freestanding cantilevers that are readily bent by thermal or intrinsic stress induced by the deposition of a different material. In the present work, we propose a new process by which patterns produced by nanostencil lithography can be reversed, so that the final pattern on the substrate has the same contrast (filled or empty) as that of the stencil. Because an open and a closed region of the stencil are transferred as an empty and a filled area on the substrate, respectively, we could not only produce isolated empty shapes but also avoid the widening of a narrow bridge pattern by the stress-induced bending of the membrane.
Record created on 2006-09-19, modified on 2016-08-08