Minimizing disruptive effects of high voltage discharges in ion implanters

Methods are described for modeling and measuring HV (high voltage) discharge current flow in ion implanters. It is pointed out that energy sorted in HV structures of an ion implanter can become a powerful source of electromagnetic interference (EMI), if it is abruptly discharged into the vacuum chamber through which the ion beam is transported. Analog circuit simulation models and a simple experimental technique were used to study the discharge characteristics of Eaton´s implanters. As a result of these studies design practices have been changed to reduce sorted energy and radiating loop areas in the affected regions. Fault current paths are now designed and consistent. Related measures have improved the integrity of the source electronics enclosure as a Faraday cage for the control electronics within it