Evaluating probes for "electrical" atomic force microscopy

The availability of very sharp, wear-proof, electrically conductive probes is one crucial issue for conductive atomic force microscopy (AFM) technique s such as scanning capacitance microscopy; scanning spreading resistance mi croscopy, and nanopotentiometry. The purpose of this systematic study is to give an overview of the existing probes and to evaluate their performance for the electrical techniques with emphasis on applications on Si at high c ontact forces. The suitability of the characterized probes has been demonst rated by applying Conductive AEM techniques to test structures and state-of -the-art semiconductor devices. Two classes. of probes were examined geomet rically and electrically: Si sensors with a conductive coating and integrat ed pyramidal tips made of metal or diamond. Structural information about th e conductive materials was obtained by electron microscopy and other analyt ical tools. Swift and nondestructive procedures to characterize the geometr ical and electrical properties of the probes prior to the actual AFM experi ment have been developed. Existing contact models have been used to explain variations in the electrical performance of the conductive probes. (C) 200 0 American Vacuum Society. [S0734-211X(00)01901-6].