COMPUTER CONTROL OF SURFACE IMPURITY BY SPREADING RESISTANCE.

The spreading resistance technique has been instrumental in the characterization of semiconductor devices by profiling. With the implementation of software-controlled calibration parameters, the technique may also be used to monitor the impurity concentration (Co) of an epitaxial layer on a real time basis in a manufacturing environment. The advantages of this technique are real time surface Co control at the epi reactor, operator independency of the measurement tool and the reactor, and reduced down time for probe wear and recalibration.