In situ ion beam current monitoring and control in a scanning ion implantation system.

摘要

A system and method for controlling an ion implantation system as a function of ion beam current and uniformity of the ion beam current. The ion implantation system includes optical elements that selectively steer and / or shape the ion beam as it is transported. The ion beam is sampled at a high frequency to provide an ion beam current sample. The ion beam current samples are then analyzed to detect variations, non-uniformities, or unexpected edges between the ion beam current samples. These beam current samples are compared to a predetermined threshold level and / or a predicted non-uniformity level. Thereby, a control signal can be generated when the non-uniformity detected in the plurality of ion beam current density samples exceeds a predetermined threshold. The control system generates a control signal for (i) interlocking beam transport or (ii) changing an input to at least one optical element to control changes in beam current.