Sensitivity study of micro four-point probe measurements on small samples

The authors calculate the sensitivities of micro four-point probe sheet resistance and Hall effect measurements to the local transport properties of nonuniform material samples. With in-line four-point probes, the measured dual configuration sheet resistance is more sensitive near the inner two probes than near the outer ones.

The sensitive area is defined for infinite film, circular, square, and rectangular test pads, and convergent sensitivities are observed for small samples. The simulations show that the Hall sheet resistance RH in micro Hall measurements with position error suppression is sensitive to both local carrier density and local carrier mobility because the position calculation is affected in the two pseudo-sheet-resistance measurements needed for the position error suppression.

Furthermore, they have also simulated the sensitivity for the resistance difference DeltaRBB[prime] of two specific configurations to clarify the effect of the calculated position, which results in an unexpected sensitivity to the local carrier mobility. ©2010 American Vacuum Society