Novel Approach of Backside Lithography Using Dynamic Magnetic Mask

The Magnetolithography (ML) method is a bottom-up method but at the same time it provides the desired high-Throughput capabilities for mass production. It is based on 'patterning' a magnetic field on a substrate by applying a constant magnet and using paramagnetic metal masks that define the spatial distribution and shape of the applied field. The second component in ML is ferromagnetic nanoparticles that are assembled onto the substrate according to the field induced by the mask. Similar to photolithography, ML can be used to apply either a positive or negative approach. The ML method simplifies chemical surface patterning because it does not require resist, which may contaminate the substrate, does not depend on the surface topography and planarity, and can pattern non-flat surfaces and the inside surfaces of a closed volume. Since a mask is applied, it is possible to achieve high production throughput. Unlike other lithography methods, ML uses backside lithography, which can easily produce multilayers with highly accurate alignment and with the same efficiency for all layers. ML allows formation of a multistep process without removing the substrate from the solution. The ML method is a single-step process and is much simpler and less expensive to apply than the common photolithography method. Moreover, ML does not require application of resists; therefore, the surfaces remain clean and can be easily modified chemically as needed. Importantly, the ML method opens up new possibilities in high throughput surface patterning since the same method can be used for all types of surfaces by combining the ability to pattern surfaces both for electronics and chemical/bioprocesses.