The Resistivity Correction Factor (RCF) is changed with the sample shapes and sizes as well
as measuring positions. In the 4-pin probe method, since the sample size or measuring position
are not fixed, the electric energy distributed in the sample is changed with the sample size and
the measuring positions. If the sample size is small or the measuring position is near the sample
edge, the peak of the electric field becomes higher to yield a high resistance. This is caused by
the electric energy being contained in the sample. The Resistivity Correction Factor is used to
obtain correct values for the volume or surface resistivity by forecasting such difference in the
peak of the electric energy. The electric potential Φ(r) in an optional point in a sample and is
calculated by solving a Poisson’s equation under a specific condition.