Plasma processing apparatus and plasma processing method

A plasma processing apparatus, comprising:

• a chamber;
• an introducing part configured to introduce process gas into the chamber;
• a substrate electrode disposed in the chamber and comprising a plurality of first electrode elements and a plurality of second electrode elements, each of the first electrode elements and each of the second electrode elements being alternately arranged, and having a column shape with an axis, the axes of the first and the second electrode elements being substantially in parallel to each other and to a main surface of the substrate;
• a counter electrode disposed in the chamber and being grounded;
• a substrate holder configured to hold a substrate between the counter electrode and the substrate electrode;
• a high-frequency power source configured to apply a high-frequency voltage of 40 MHz or more to the first and the second electrode elements to generate plasma between the substrate and the counter electrode;
• a first low-frequency power source configured to apply a first low-frequency voltage of 20 MHz or less to the first electrode elements to superimpose the high-frequency voltage and the first low-frequency voltage at the first electrode elements;
• a second low-frequency power source configured to apply a second low-frequency voltage of 20 MHz or less to the second electrode elements to superimpose the high-frequency voltage and the second low-frequency voltage at the second electrode elements;
• a first high-frequency filter disposed between the high frequency power source and the first electrode elements and configured to pass the high-frequency voltage and not to pass the first low-frequency voltage;
• a second high-frequency filter disposed between the high frequency power source and the second electrode elements and configured to pass the high-frequency voltage and not to pass the second low-frequency voltage;
• a first low-frequency filter disposed between the first low frequency power source and the first electrode elements and configured to pass the first low-frequency voltage and not to pass the high-frequency voltage;
• and
• a second low-frequency filter disposed between the second low frequency power source and the second electrode elements and configured to pass the second low-frequency voltage and not to pass the high-frequency voltage,
• wherein the phase of the first low-frequency voltage applied to the first electrode elements is different from the phase of the second low-frequency voltage applied to the second electrode elements by approximately π/2 or −π/2, and
• wherein the phase of the high-frequency voltage applied to the first electrode elements is substantially as same as the phase of the high-frequency voltage applied to the second electrode elements.