Patent ID: 6943571
Filing Date: 2005-09-13
Classification: G01R

Abstract:
1. A method for measuring a resistance, R, of a material having a surface using a multi-point probe comprising four or more substantially collinear contact points, the method comprising: making a first measurement using a first set of probe electrodes for inducing a current and a second set of probe electrodes for measuring a first voltage difference when the current is induced; making a second measurement using a set of probe electrodes different from the first set for inducing a current and a set of probe electrodes different from the second set for measuring a second voltage difference when the current is induced; and using a known relationship among the currents induced, the voltages measured, the nominal probe positions and the resistance per square to determine the resistance per square such that measurement errors resulting from positioning of the probes are reduced; wherein the multi-point probe comprises contact points a, b, c, and d; wherein the points located along a horizontal axis on the surface at locations (0,0), (x,0), (y,0) and (z,0) respectively, such that x is greater than 0, y is greater than x, and z is greater than y; the resistance measured is resistance per square, and wherein the method comprises: inducing a current between points a and d; measuring a voltage difference between point b and point c; reporting a resistance measurement A; inducing a current between points a and c; measuring a voltage difference between point b and point d; reporting a resistance measurement B; and determining the resistance per square, R R