A 4-kV/2-A/5-kHz Compact Modulator for Nitrogen Plasma Ion Implantation

To treat stainless-steel surfaces by nitrogen plasma implantation, a solid-state compact modulator was devised, in which a 8.0-muF capacitor discharges through a forward converter composed of a low-blocking-voltage insulated-gate-bipolar-transistor switch (1.0 kV) and three step-up pulse transformers, rather than employing hard-tube devices such as in conventional plasma ion implantation pulsers, which are expensive and cumbersome. For this, a modulator was built to produce pulses with amplitudes of the order of 4 kV, duration of about 5.0 mus, and rise time of ~1.0 mus with maximum current/frequencies capabilities of 2.0 A and 5 kHz, respectively