Direct-write patterning on flexible substrates using scanning probe-based electrolithography technique

Electric field induced liquefaction of chromium (Cr) thin films is at the heart of a scanning probe-based lithography technique, known as electrolithography (ELG). Very fine patterns, only a few nanometers wide, have been fabricated using the ELG technique. The formed liquefied material, on electrically stressed Cr films, is easily dissolvable in water and can thereby be removed quite easily, resulting in openings on the Cr layer. The said process is extremely aggressive, and a plethora of ambient, electrical and mechanical factors are known to help in tuning the said process. Though the ELG process involves patterning Cr thin films, a sandwiched polymer layer between the Cr film and the substrate can help easily transfer the pattern onto a material of choice. In this work, we demonstrate ELG’s capability in patterning Cr thin films deposited on a flexible substrate. The multiscale patterns formed after the lithography process involved circles with diameters ranging from a few tens on micrometers to almost a millimeter, encompassing the wide range of feature sizes used for developing electronic circuits on flexible substrates. Furthermore, the results presented in this study exemplify the diverse nature of devices which can be patterned and fabricated with the help of the ELG process.