Semiconductor device manufacturing system for etching a semiconductor by plasma discharge

A semiconductor device manufacturing system comprising:

• a vacuum chamber provided with a cathode electrode for holding a substrate to be processed and into which a reactive gas for generating discharging plasma by the application of a high-frequency electric power is introduced;
• a high-frequency power supply connected to said cathode electrode, for applying a high-frequency electric power to said cathode electrode;
• a measuring circuit connected to said cathode electrode, for measuring at least one of the impedance of a system including said plasma, the peak-to-peak voltage of a high-frequency signal applied to said plasma, and a self-bias voltage applied to said cathode electrode;
• and
• a report circuit configured to receive the measured value from said measuring circuit, and to correlate said measured value with a diameter of a trench in the substrate.