Four-Probe Resistivity and Hall Voltage Measurements

Four-Probe Resistivity and Hall Voltage Measurements

Semiconductor material research and device testing often involve determining the resistivity and Hall mobility of a sample. The resistivity is often determined using a four-point probe or Kelvin technique, in which two of the probes are used to source current and the other two probes are used to measure voltage. Using four probes eliminates measurement errors due to the probe resistance, the spreading resistance under each probe, and the contact resistance between each metal probe and the semiconductor material. This application note describes tools and techniques for making better resistivity measurements of semiconductor materials. ■