Plasma Processing Method And Plasma Processing Apparatus

A plasma processing method for processing a sample by applying a high-frequency bias power for each period (T) which is divided into a first sub-period (T1), a second sub-period (T2), and a third sub-period (T3) along a time axis;

• wherein the first sub-period is used as a sub-period for which feedback control of a CD gain is executed;
• the second sub-period is used a sub-period for which feedback control of a select ratio is executed;
• and
• the third sub-periods is used as a sub-period for which feedback control of the CD gain and feedback control of the select ratio are executed;
• wherein the applied power is set at a large value in the first sub-period;
• wherein a duty ratio T1/T is controlled in accordance with the CD gain;
• and
• wherein the processing method comprises the steps of:
• processing a plurality of samples with a predetermined processing condition;
• and
• executing a feedback control for each processing unit of the samples in accordance with a change of processing state of each of the samples so that an average applied power over each of the period (T) is constant.