Nano lithography techniques can be broadly classified into two categories: top-down and bottom-up approaches. The top-down approach involves the etching away of material to achieve the desired nanostructure, while the bottom-up approach builds structures atom-by-atom or molecule-by-molecule. Techniques such as electron-beam lithography (EBL), scanning probe lithography (SPL), and nanoimprint lithography (NIL) are commonly used in top-down methods.
