Noncontacting measurement of hall effect in a wafer

摘要

The magnitude and sign of the Hall angle of the material of a wafer (13) are measured by a combined capacitive and inductive coupling technique which does not require physically contacting the wafer (13). Contacting methods in common use introduce surface damage or contamination which may reduce the yield of microelectronic circuits on semiconductor wafers and normally in addition require special sample geometries. In this technique an rf signal is applied to a pair of concentric planar electrodes (11,12) adjacent to the wafer (13), thus capacitively coupling a radial rf current into the wafer. A magnetic field applied perpendicular to the wafer produces a circular component of rf current because of the Hall effect. This circular rf current produces an axial rf magnetic field which couples to a pickup coil (15). The pickup signal is amplified and detected to produce an output signal related to the sign and magnitude of the Hall angle of the wafer material.