Nanolithography based on real-time electrically controlled indentation with an atomic force microscope for nanocontact elaboration

We report on the fabrication of nanocontacts by indentation of an ultrathin insulating photoresist layer deposited on various types of conductive structures. A modified atomic force microscope (AFM) designed for local resistance measurements is used as a nanoindenter. The nanoindentation is performed while measuring continuously the resistance between the conductive tip of the AFM and the conductive layer, which is used as the trigger parameter to stop the indentation. This allows a very accurate control of the indentation process, The indented hole is subsequently filled by a metal to create a contact on the underlying layer. We show that nanocontacts; in the range of 1 to 10 nm(2) can be created with this technique.