Nanoimprint lithography: A competitive fabrication technique towards nanodevices
The challenges of making the fabrication of both electronic and optical devices more competitive have led to an upsurge in research activity in numerous lithographic techniques, which include but are not limited to microcontact printing, photolithography and electron-beam lithography. Alternative lithographic techniques, in particular nanoimprint lithography (NIL), are emerging as a unique and viable novel nanofabrication approach towards the goal of submicrometre devices. The concept of three-dimensional (3D) NIL is relatively new and is being defined. It ranges from the fabrication of 3D nanostructured stamps, and subsequent imprints, to imprinting in multilayers. NIL is based on the deformation of a thin polymer film with a rigid mould. Limitations in the resolution of the NIL technique are solely attributed to the minimum feature size of the master stamp, with the minimum feature achieved being 6 nm, and the inherent viscoelastic properties of the polymer.