Cathodic arc modulator systems for metallic plasma ion implantation

This paper describes the electrical design and operation of a cathodic arc modulator system for metallic plasma ion implantation. Depending on the ion implantation process recipe, various repetition rates, pulse widths and currents are required. In addition, the cathodic arc system may be synchronized with a higher voltage “target” modulator system. The cathodic arc is water cooled and usually uses a self-generated axial B-field, by use of a series connected solenoid around the arc anode. Typical arc currents of 800 amperes may be utilized with pulse widths ranging from 20 μS to 4 mS. Typical pulse repetition frequencies may exceed 400 Hz, with overall system power limited by the presently available 10 kW transformer-rectifier. The cathodic arc modulator system consists of a command charged 10 kV trigger generator, a high voltage arc “starter”, and a low voltage, high current arc sustain circuit. The arc start and sustain circuits are independently adjustable and utilize a common IGBT device in a “hot-deck” configuration. This paper will provide circuit design and performance information in addition to various process applications