Apparatus and method for plasma processing

A plasma processing method comprising:

• providing a lower electrode for placing an object to be processed thereon;
• providing an upper electrode disposed above the lower electrode and opposing the lower electrode;
• providing an adjusting mechanism that adjusts a spacing between the upper and lower electrodes by raising or lowering the lower electrode, the adjusting mechanism including a drive mechanism;
• providing a variable DC voltage source that applies DC voltage to the lower electrode;
• providing a first high-frequency power supply that applies first high-frequency power to the upper electrode, the first high-frequency power being applied to the upper electrode to cause plasma ignition;
• providing a second high-frequency power supply that applies second high-frequency power to the lower electrode;
• applying the DC voltage to the lower electrode;
• applying a first value of the first high-frequency power to the upper electrode;
• applying a second value of the second high-frequency power to the lower electrode;
• minimizing an amount of charge on devices on the object for an igniting duration by maintaining the spacing during the igniting period at a constant second spacing, which is larger than a constant first spacing, for an initial period of time immediately after the time of plasma ignition;
• subsequently setting the spacing from the constant second spacing directly to the constant first spacing;
• minimizing the amount of charge on devices on the object for an extinction duration by subsequently setting the spacing from the constant first spacing directly to the constant second spacing, before the time of plasma extinction;
• subsequently decreasing the first high-frequency power from the first value of the first high-frequency power to a third value of the first high-frequency power, decreasing a flow of processing gas, increasing pressure of a chamber, turning off the second high-frequency power from the second value of the second high-frequency power, and turning off the first high-frequency power from the third value of the first high-frequency power;
• and
• subsequently turning off the variable DC voltage source.