Conductive diamond tips with sub-nanometer electrical resolution for characterization of nanoelectronics device structures

Over the past decade, boron-doped diamond tips have become the ultimate choice for electrically characterizing microelectronics devices using scanning probe methods such as scanning spreading resistance microscopy (SSRM). Although nanometer-scale electrical resolution has been demonstrated, the development of a reliable probe process remained a challenge. Therefore, we did develop in this work solid diamond tips with sub-nanometer electrical resolution and integrated them into metal cantilevers using a peel-off approach. It is shown that the ultra-high tip resolution is achieved by diamond nanocrystals protruding from the apex of the diamond pyramid. The yield for sub-nanometer probes is 20-30% in air and 40-60% in vacuum. This paper describes the fabrication scheme, discusses probe characterization, and shows SSRM measurements obtained with these probes. Our probes are routinely used for SSRM measurements and current efforts are focusing on increasing the yield for sub-nanometer tips further. (C) 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim