Null method for four-point probe measurement using high resistance probes

Abstract

A null method, using a bridged circuit, is applied to the so-called four-point probe method using highly resistance probes. A commercial resistor (150 kΩ-10 MΩ) is serially connected with a voltage measurement probe (made of tungsten) in order to give high resistance. The resistivity of a patterned Pt-Pd film about 50 nm thick is successfully measured for the probe spacing down to the submicron scale. The obtained values of resistance remain unchanged irrespective of the inserted resistors. © 2006 The Surface Science Society of Japan.