The effect of the target surface area to the current and voltage characteristics of a pulsed modulator for plasma-based ion implantation and deposition process

A pulse modulator using a two-switch mode for plasma-based ion implantation and deposition (PBII & D) has been developed for stable operation and increase of current capacity. Even for capacitive load, the voltage waveform shows a rectangular shape. The target with diameters from 40 to 300 mm is immersed in a cathodic arc generated in a vacuum chamber with a size of 340/spl times/380/spl times/600 mm. Although the electrical characteristics at a rising portion of the voltage application are strongly influenced by a stray capacitance, the voltage returns to its original state in a time less than 1 /spl mu/s after a designated pulse width. A maximum output voltage is 40 kV with an average current of 20 A, where the pulse width is varied from 2 /spl mu/s to 100 /spl mu/s at a maximum repetition rate of 2.5 kHz.