Preventing dosage drift with duplicate dose integrators

摘要

A method for identifying a drifted dose integrator in an implantation system and an implantation system are provided. The implantation system includes a first dose integrator and a second dose integrator. The first dose integrator includes a first input configured to receive a first current generated from charges carried by implanted ions in a wafer, and a first output configured to output a first accumulated dosage value. The second dose integrator includes a second dose integrator including a second input configured to receive a second current generated from the charges carried by the implanted ions in the wafer, and a second output configured to output a second accumulated dosage value. The implantation system further includes a processing unit comparing the first accumulated dosage value and the second accumulated dosage value to detect a drift in one of the first and the second dose integrators.