Patent ID: 8637838

Claim:
An ion implantation system comprising: an ion source configured to generate an ion beam along a beam path; a mass analysis component downstream of the ion source configured to perform mass analysis on the ion beam; a scanning element located downstream of ion source configured to produce a time-varying field which operates upon the ion beam to produce a scanned beam that traverses a scan path; a beam profiling system configured to measure a beam current of the scanned beam as the scanned beam traverses the scan path; an analysis system to analyze the measured beam current to detect a zero field effect (ZFE) condition arising from scanning; a ZFE-limiting element upstream of the beam profiler and coupled to the analysis system via a feedback path, wherein the ZFE-limiting element is configured to limited the ZFE condition, if detected, by selectively applying an electric field to the ion beam based on whether a ZFE condition was detected.