Dc Plasma Power Supply

DC and pulsed-DC plasma power supplies drive sputtering and similar processes with continuous or interrupted direct current instead of RF, a simpler power format that works well for conductive targets but needs the pulsed variant's periodic polarity reversal to avoid the arcing problem that shows up with insulating or partially-insulating targets.

Continuous DC remains the simplest and most efficient choice specifically for fully conductive metal targets, where there's no insulating layer to accumulate the charge that causes arcing in the first place. A pure metal sputtering target conducts away any charge buildup on its surface continuously, so a steady, unmodulated DC power supply sustains the sputtering discharge reliably without the periodic reset a pulsed supply exists to provide — which is why simple continuous DC remains standard for straightforward metal sputtering where nothing about the target surface traps charge.

Pulsed-DC power supplies specifically protect against the arcing that would otherwise occur during reactive sputtering or on any target that develops even a thin insulating layer. Reactive sputtering processes that form an oxide or nitride compound can leave an insulating film forming directly on parts of the target itself, which accumulates charge and risks a damaging arc under continuous DC power; the pulsed-DC supply's brief, periodic reverse-polarity pulses discharge that buildup before it reaches arcing threshold, the same principle covered in the pulsed-DC sputtering discussion but here as the power-supply hardware delivering it.

DC and pulsed-DC power supplies both drive the same basic sputtering mechanism, and the choice between simple continuous delivery and periodically-reversed pulsed delivery comes down entirely to whether the target surface can accumulate problematic charge during the process.