SEMICONDUCTOR PROCESSING APPARATUS

A semiconductor processing apparatus includes an upper electrode and a substrate on a lower electrode disposed inside the process chamber, a first power generator configured to provide a low-frequency signal to the lower electrode, wherein the low-frequency signal varies between a reference voltage and a first voltage at intervals of a first cycle, a second power generator configured to provide a high-frequency signal to the lower electrode, wherein the high-frequency signal has a sinusoidal waveform that oscillates at intervals of a second cycle shorter than the first cycle, and a direct-current (DC) power generator configured to provide a DC bias to the upper electrode. The high-frequency signal is turned off during at least part of a duration for which the low-frequency signal has the first voltage, and the high-frequency signal is turned on and turned off at intervals of a third cycle different from the first and second cycles.