Patent ID: 6989545

Claim:
An ion implantation system comprising: an ion beam generation mechanism that generates and directs an ion beam toward a target wafer and scans across the target wafer in a horizontal direction; a module located downstream of the ion beam that supports the target wafer and moves the target wafer through the ion beam in a vertical direction; and a divergence detector located downstream of the ion beam that obtains vertical angle of incidence values of the ion beam and obtains a vertical divergence profile there from, wherein the divergence detector includes a mask that selectively obtains beamlets from the ion beam, a sensor that measures beam current at a plurality of vertical locations for the beamlets, wherein the sensor is comprised of a plurality of finger sensors that obtain individual beam current measurements, and circuitry that determines centroid locations of the beamlets from individual beam current measurements and compares the centroid locations with expected locations to determine vertical angle of incidence values for the beamlets.