  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 an extremely 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 nm2 can be created with this technique.
