Cleaning method and plasma processing apparatus
A plasma processing apparatus includes: a plasma processing chamber; a substrate support disposed in the plasma processing chamber; an edge ring disposed on the substrate support to surround a substrate on the substrate support; an actuator configured to vertically move the edge ring; a gas supply configured to supply a cleaning gas into the plasma processing chamber; a power source configured to supply a power to the substrate support; and a controller configured to: (a) maintain the edge ring at a first position spaced apart from the substrate support; and (b) supply a power to the substrate support while supplying the cleaning gas into the plasma processing chamber to generate a local plasma in a gap between the edge ring maintained at the first position and the substrate support, thereby cleaning the edge ring and the substrate support.
1. A plasma processing apparatus comprising:
a plasma processing chamber;
a substrate support disposed in the plasma processing chamber, the substrate support including:
a lower electrode;
a first electrostatic chuck;
and a second electrostatic chuck;
an edge ring disposed that surrounds a substrate on the substrate support;
an actuator configured to vertically move the edge ring between an upper position and a lower position, wherein in the upper position, a gap is formed between the edge ring and the second electrostatic chuck;
a gas supply configured to supply a cleaning gas into the plasma processing chamber during a cleaning operation;
the second electrostatic chuck having at least one ring electrode and the second electrostatic chuck being disposed below the edge ring in the substrate support, wherein the second electrostatic chuck is disposed between the edge ring and the lower electrode, such that the edge ring overlaps the second electrostatic chuck and the lower electrode in a vertical direction;
a first RF generator configured to supply a first RF signal to the at least one ring electrode of the second electrostatic chuck; and
a controller configured to control the gas supply to supply the cleaning gas into the plasma processing chamber and control the first RF generator to supply the first RF signal to the at least one ring electrode of the second electrostatic chuck to generate a plasma from the cleaning gas in the gap while the edge ring is maintained at the upper position to cause the edge ring and the second electrostatic chuck to be cleaned by the plasma, wherein during the cleaning operation, RF signals are not supplied to the lower electrode or the first electrostatic chuck.
2. The plasma processing apparatus according to claim 1 , wherein the second electrostatic chuck further includes:
at least one adsorption electrode disposed below the edge ring in the substrate support; and
at least one DC power supply connected to the at least one adsorption electrode.
3. The plasma processing apparatus according to claim 2 , wherein
the at least one adsorption electrode of the second electrostatic chuck includes first and second adsorption electrodes, and
the at least one DC power supply of the second electrostatic chuck includes a first DC power supply connected to the first adsorption electrode and a second DC power supply connected to the second adsorption electrode.
4. The plasma processing apparatus according to claim 3 , wherein the first and second adsorption electrodes are disposed above the at least one ring electrode.
5. The plasma processing apparatus according to claim 1 , wherein the at least one ring electrode includes first and second ring electrodes.
6. The plasma processing apparatus according to claim 5 , further comprising:
a first DC power supply connected to the first ring electrode;
a second DC power supply connected to the second ring electrode;
a first blocking element connected between the first ring electrode and the first RF generator; and
a second blocking element connected between the second ring electrode and the first RF generator.
7. The plasma processing apparatus according to claim 1 , wherein
the first electrostatic chuck is disposed on the lower electrode and has a substrate placing surface; and
the substrate support includes a substrate electrode disposed below the substrate placing surface in the first electrostatic chuck.
8. The plasma processing apparatus according to claim 7 , wherein the second electrostatic chuck is disposed on the lower electrode and surrounds the first electrostatic chuck.
9. The plasma processing apparatus according to claim 7 , further comprising a second RF generator connected to the substrate electrode.
10. The plasma processing apparatus according to claim 9 , further comprising a third RF generator connected to the lower electrode.
11. The plasma processing apparatus according to claim 7 , wherein the first RF generator is connected to the at least one ring electrode and the substrate electrode.
12. The plasma processing apparatus according to claim 11 , further comprising a first switch connected between the first RF generator and the at least one ring electrode.
13. The plasma processing apparatus according to claim 12 , further comprising a second switch connected between the first RF generator and the substrate electrode.
14. The plasma processing apparatus according to claim 1 , wherein
the first electrostatic chuck is disposed on the lower electrode and has a substrate placing surface.
15. The plasma processing apparatus according to claim 14 , wherein the second electrostatic chuck is disposed on the lower electrode and surrounds the first electrostatic chuck, and the at least one ring electrode is disposed in the second electrostatic chuck.
16. The plasma processing apparatus according to claim 14 , further comprising a second RF generator connected to the lower electrode.
17. The plasma processing apparatus according to claim 16 , further comprising a third RF generator connected to the lower electrode.
18. A plasma processing apparatus comprising:
a plasma processing chamber;
a substrate support disposed in the plasma processing chamber, the substrate support including:
a lower electrode;
a first electrostatic chuck; and
a second electrostatic chuck;
an edge ring disposed that surrounds a substrate on the substrate support;
an actuator configured to vertically move the edge ring between an upper position and a lower position,
wherein in the upper position, a gap is formed between the edge ring and the second electrostatic chuck;
a gas supply configured to supply a cleaning gas into the plasma processing chamber during a cleaning operation;
the second electrostatic chuck having at least one ring electrode and the second electrostatic chuck being disposed below the edge ring in the substrate support, wherein the second electrostatic chuck is disposed between the edge ring and the lower electrode, such that the edge ring overlaps the second electrostatic chuck and the lower electrode in a vertical direction;
a first RF generator configured to supply a first RF signal to the at least one ring electrode of the second electrostatic chuck; and
a controller configured to control the gas supply to supply the cleaning gas into the plasma processing chamber and control the first RF generator to supply the first RF signal to the at least one ring electrode of the second electrostatic chuck to generate a plasma from the cleaning gas in the gap while the edge ring is maintained at the upper position to cause the edge ring and the second electrostatic chuck to be cleaned by the plasma, wherein during the cleaning operation, an RF signal is supplied to the lower electrode, but not to the first electrostatic chuck.