Measurement of sheet resistance of cross microareas using a modified van der Pauw method

The sheet resistance of a cross microarea with a size as small as 120 mu m was determined by using a modified van der Pauw method, in which the tip positions of four probes were controlled at the peripheral areas outside a demarcation curve, as shown in the text, by direct inspection through a microscope with a magnification of 4 x 20. It is not necessary to prepare four metallized electrodes for setting probes. The measurement results are independent of the wanderings of probes and it is unnecessary to determine the precise positions of probes in order to make corrections for the boundary effect. These conclusions have been proved in this paper by using the finite element method (FEM) and have been confirmed by the experimental determination of sheet resistance for several boron-doped cross microareas isolated by p-n junctions on an n-type silicon wafer.