Ferrofluid Masking for Lithographic Applications
B. Yellen and G. Friedman
Drexel University, US
Keywords: ferrofluid, self-assembly, self-aligning, masking
A novel self-aligned ''soft masking'' method that is compatible with traditional photolithographic processes is demonstrated. This method uses a suspension of ultra-fine iron oxide grains (ferrofluid) to protect or de-protect selected areas of a magnetically patterned substrate according to a programmable sequence. Automatic mask formation and registration is controlled by ferromagnetic alignment marks patterned on a substrate. External magnetic field bias applied to the system causes ferrofluid to aggregate only over designated areas on the surface, thereby masking those areas from UV or chemical exposure.
Nanotech 2004 Conference Technical Program Abstract