Capacitive coupling plasma processing apparatus
A capacitive coupling plasma processing apparatus includes a process chamber configured to have a vacuum atmosphere, and a process gas supply section configured to supply a process gas into the chamber. In the chamber, a first electrode and a second electrode are disposed opposite each other. The second electrode includes a plurality of conductive segments separated from each other and facing the first electrode. An RF power supply is configured to apply an RF power to the first electrode to form an RF electric field within a plasma generation region between the first and second electrodes, so as to turn the process gas into plasma by the RF electric field. A DC power supply is configured to apply a DC voltage to at least one of the segments of the second electrode.
1. A capacitive coupling plasma processing apparatus comprising;
a chamber configured to maintain a vacuum atmosphere;
first and second electrodes disposed opposite to each other inside the chamber; and
a plasma generation mechanism configured to generate process gas plasma by forming a radio frequency (RF) electric field between the first and second electrodes,
wherein the plasma generation mechanism includes an RF power supply connected to the first electrode,
the first electrode is configured to support a process target substrate and to be supplied with an RF power from the RF power supply,
the second electrode includes a plurality of segments separated in concentric state and disposed at a position opposite to the first electrode, and a conductive main body supporting the plurality of segments through a planar insulating film in an integrated state, such that the main body is grounded and the plurality of segments are set in a floating state or is grounded via a conductive portion,
the apparatus further comprises variable direct current (DC) power supplies for applying a DC voltage to at least one of the plurality of segments, to control spatial electric potential distribution in radial directions of the second electrode by applying a DC voltage to at least one of the plurality of segments from the variable DC power supplies, and
the plurality of segments include a first segment and a second segment, and the variable DC power supplies include a first variable DC power supply configured to apply a DC voltage to the first segment, and a second variable DC power supply configured to apply a DC voltage to the second segment independently of the first segment.
2. The apparatus according to claim 1 , wherein the first and second variable DC power supplies are configured to set a voltage between the first and second segments.
3. The apparatus according to claim 1 , wherein the first variable DC power supply is configured to set a voltage between the first and second segments.
4. The apparatus according to claim 3 , wherein the first variable DC power supply includes one terminal connected to the first segment and another terminal connected to the second segment.
5. The apparatus according to claim 4 , wherein one of the first segment and the second segment is grounded and the other is set in a floating state.
6. The apparatus according to claim 4 , wherein the second variable DC power supply includes one terminal connected to the second segment and another terminal that is grounded.
7. The apparatus according to claim 4 , wherein the first variable DC power supply includes a positive terminal connected to an inner segment of the first and second segments and a negative terminal connected to an outer segment of the first and second segments.
8. The apparatus according to claim 5 , wherein an inner segment of the first and second segments is set in a floating state, and the first variable DC power supply includes a positive terminal connected to the segment set in a floating state and a negative terminal connected to the segment that is grounded.
9. The apparatus according to claim 6 , wherein the first variable DC power supply includes a positive terminal connected to an inner segment of the first and second segments and a negative terminal connected to an outer segment of the first and second segments, and the second variable DC power supply includes a positive terminal connected to the outer segment.
10. The apparatus according to claim 1 , wherein each of the first and second variable DC power supplies is a bipolar power supply.
11. The apparatus according to claim 1 , wherein each of the first and second segments is arranged to form a mesh.
12. The apparatus according to claim 1 , wherein the apparatus further comprises switches respectively disposed between the first and second variable DC power supplies and the first and second segments to turn on and off a DC voltage.
13. The apparatus according to claim 1 , wherein the apparatus further comprises low-pass filters respectively disposed between the first and second variable DC power supplies and the first and second segments.
14. The apparatus according to claim 1 , wherein an inner segment of the first and second segments is set to have electric potential higher than that of an outer segment of the first and second segments.