Heated membranes prevent clogging of apertures in nanostencil lithography

We demonstrate a novel concept for nanostencil lithography with an integrated microhotplate on the stencil membrane aimed at eliminating or reducing aperture clogging during metal deposition. The stencil can be locally heated up by the embedded Pt coils to more than 700°C in order to minimize materials´ accumulation on the membrane. FEM simulation was carried out to predict the temperature distribution across the heated membrane, which agrees well with the experimental results in ambient conditions. 120 nm Aluminum depositions through heated and non-heated stencils were performed simultaneously in an electron-beam evaporator. No clogging was found on the heated membrane whereas a clear shrinkage of the aperture was observed on the non-heated one. This method could significantly extend the life time of the stencil, especially for thick deposited layers, e.g.in the dynamic mode.