Stability Analysis of High-Voltage Power Supplies for Etching Equipment

Etching processes rely on plasma uniformity and precise ion energy, both of which are directly influenced by high-voltage supply stability. Voltage or current instability leads to plasma density fluctuations, impacting etch rate, selectivity, and uniformity.
High-voltage etching power supplies utilize multi-loop regulation, with an inner loop controlling current and an outer loop maintaining voltage. High-speed sampling and digital controllers enable microsecond-level compensation for load variations and environmental disturbances. Stability analysis must account for parasitic capacitance, inductance, and switching device characteristics, which can induce oscillations or high-frequency ripple.
Optimized circuit layout, low-ESR capacitors, and high-speed switches reduce transient effects. Active filtering and digital compensation maintain voltage fluctuation below 0.05%, ensuring uniform plasma characteristics. Such stability is essential for precision etching in semiconductor fabrication, providing consistent process outcomes across extended operation.