Development of high voltage pulse modulator for plasma source ion implantation

High voltage pulse modulator of hard tube type has been developed for plasma source ion implantation (PSII). In this modulator, the crowbar switch is required for the excellent performance of PSII process which is different from conventional PSII. In order to reduce the falling time of pulse, the crowbar switch is used to PSII system. The arc response time for steady operation was designed with 500 ns. The current capacity is 120 A during the pulse at an output voltage of 60 kV. The total pulse length is varied from 3 to 12 us under a maximum repetition rate is 2 kHz. The maximum pulse duty is 0.012. The average power is 40 kW. In this article, we introduce the various type of modulator for PSII and show the performance of the developed modulator.