Progress on high-voltage pulse generators, using low voltage semiconductors (<1 kV), designed for plasma immersion ion implantation (PIII)

A modular concept on high-voltage pulse generators, under development for future use in facilities for plasma immersion ion implantation, is presented. The generator proposed uses individual modules, each one consisting of a pulse circuit based on a step-up transformer; the secondary of each step-up transformer is connected in series. Each step-up transformer delivers a fraction of the total voltage with primary voltage supplied via an isolation transformer. With this topology we expect to achieve tens of kiloVolts with low voltage semiconductor switches (<1 kV). A three 5 kV-module initial prototype was assembled with 800 V semiconductor switches and experimentally tested for an output of 11 kV, 5 μs pulse width and 10 kHz-pulse frequency. Different load conditions and results are presented and discussed.