Scanning nanoscale multiprobes for conductivity measurements

We report fabrication and measurements with two- and four-point probes with nanoscale dimensions, for high spatial resolution conductivity measurement s on surfaces and thin films. By combination of conventional microfabricati on and additive three-dimensional nanolithography, we have obtained electro de spacings down to 200 nm. At the tips of four silicon oxide microcantilev ers, narrow carbon tips are grown in converging directions and subsequently coated with a conducting layer. The probe is placed in contact with a cond ucting surface, whereby the electrode resistance can be determined. The nan oelectrodes withstand considerable contact force before breaking. The probe offers a unique possibility to position the voltage sensors, as well as th e source and drain electrodes in areas of nanoscale dimensions. (C) 2000 Am erican Institute of Physics. [S0034-6748(00)02607-1].