Full wafer size micro/nanostencil with multiple length-scale apertures

Sub-micron scale lithography methods using deep UV, X-ray or electron beams will allow for further progress in integrated circuit hardware manufacturing. The drawback of these high-end patterning methods however is firstly, the high cost of the equipment, and secondly, the limited flexibility of substrate and material combination. Increased flexibility however becomes important in nano/micro-electro-mechanical systems (NEMS/MEMS), polymer-based electronic devices, microfluidics and bio-analytical systems, etc. One major limitation of resist-based lithography is that it cannot be applied to mechanically unstable and bio/chemically functional surface layers. Recently, a new resistless nanopattering method, nanostenciling, based on local deposition through miniature shadow-masks has been developed. Solid-state membranes made by silicon nitride (SiN) have been used for the patterning of 10-100 nm scale structures within a limited area of a few 10s square-um. This limitation is given by the low stability of the freestanding membrane to sustain the mechanical stress induced by the deposited layer. To overcome this limitation we present here advances towards a full-wafer (100 mm) MEMS based nanostencil to allow high-throughput, large area nanopatterning. The main issues addressed in this paper are i) the mechanical stability of the thin SiN membrane and ii) multiple length-scale apertures ranging from 100 nm to several 100 um. The new type of stencil allows for combined micro- and nanostructures to be made side-by-side in a single evaporation step, which is a difficult task for lithography. In the presentation, we will show details of the combined micro/nanoengineering process and will demonstrate the application as multiple length scale patterning on full wafer scale.