Apparatus for automatically measuring the resistivity of semiconductor boules by using the method of four probes

An apparatus for the automated measurement and recording of the electrical resistivity of a semiconductor boule or ingot using the method of four probes. A four point boule support grid is provided adjacent to the home position of a four tip probe equipped with three axis linear mobility, rotational capability, and computer control, to enable automated mapping and testing of an "as grown" or ground semiconductor boule with cropped ends, for obtaining and recording all necessary resistivity data. The apparatus converts resistivity data to ASTM standards and reads over a wide resistivity range. The apparatus has all data logging capabilities and full computer control interfaces, and adapts readily to a production line setup with automated delivery and removal of boules under test.