Plasma processing apparatus
A plasma processing apparatus includes a plasma processing chamber, a substrate support disposed in the plasma processing chamber and including a lower electrode, an upper electrode disposed above the substrate support, a first RF signal generator coupled to the lower electrode and configured to generate a first RF signal, the first RF signal having a first power level during a first state in a repetition period, a second power level less than the first power level during a second state in the repetition period, and the second power level during a third state in the repetition period, and a second RF signal generator coupled to the lower electrode and configured to generate a second RF signal, the second RF signal having a third power level during the first state, a fourth power level greater than the third power level during the second state, and the third power level.
1 . A plasma processing apparatus comprising:
a plasma processing chamber;
a substrate support disposed in the plasma processing chamber and including a lower electrode;
an upper electrode disposed above the substrate support;
a first RF signal generator coupled to the lower electrode and configured to generate a first RF signal, the first RF signal having a first power level during a first state in a repetition period, a second power level less than the first power level during a second state in the repetition period, and the second power level during a third state in the repetition period;
a second RF signal generator coupled to the lower electrode and configured to generate a second RF signal, the second RF signal having a third power level during the first state, a fourth power level greater than the third power level during the second state, and the third power level during the third state; and
a DC signal generator coupled to the upper electrode and configured to generate a DC signal, the DC signal having a first voltage level during the first state and a second voltage level during the second state, an absolute value of the first voltage level being greater than an absolute value of the second voltage level.
2 . The plasma processing apparatus according to claim 1 , wherein the first voltage level has a negative polarity.
3 . The plasma processing apparatus according to claim 2 , wherein the DC signal has the first voltage level during the third state.
4 . The plasma processing apparatus according to claim 3 , wherein the second power level is zero power level.
5 . The plasma processing apparatus according to claim 4 , wherein the third power level is zero power level.
6 . The plasma processing apparatus according to claim 5 , wherein the second voltage level is zero voltage level.
7 . The plasma processing apparatus according to claim 6 , wherein a frequency of the first RF signal is greater than a frequency of the second RF signal.
8 . The plasma processing apparatus according to claim 1 , wherein the repetition period is in a range of 20 μs to 800 μs.
9 . The plasma processing apparatus according to claim 1 , wherein the first state is in a range of 10% to 80% of the repetition period.
10 . The plasma processing apparatus according to claim 1 , wherein the second state is in a range of 10% to 80% of the repetition period.
11 . The plasma processing apparatus according to claim 1 , wherein the third state is in a range of 10% to 80% of the repetition period.
12 . The plasma processing apparatus according to claim 1 , wherein the first voltage level is in a range of −500 V to −2500 V.
13 . A plasma processing apparatus comprising:
a plasma processing chamber;
a substrate support disposed in the plasma processing chamber and including a lower electrode;
an upper electrode disposed above the substrate support;
an RF signal generator coupled to the lower electrode and configured to generate an RF signal, the RF signal having a first power level during a first state in a repetition period, a second power level less than the first power level during a second state in the repetition period, and the second power level during a third state in the repetition period;
a first DC signal generator coupled to the lower electrode and configured to generate a first DC signal, the first DC signal having a first voltage level during the first state, a sequence of voltage pulses having a second voltage level during the second state, and the first voltage level during the third state, an absolute value of the first voltage level being less than an absolute value of the second voltage level; and
a second DC signal generator coupled to the upper electrode and configured to generate a second DC signal, the second DC signal having a third voltage level during the first state, and a fourth voltage level during the second state, an absolute value of the third voltage level being greater than an absolute value of the fourth voltage level.
14 . The plasma processing apparatus according to claim 13 , wherein the second voltage level has a negative polarity.
15 . The plasma processing apparatus according to claim 14 , wherein the sequence of voltage pulses has a pulse frequency in a range of 100 kHz to 500 kHz.
16 . The plasma processing apparatus according to claim 15 , wherein the first voltage level is zero voltage level.
17 . The plasma processing apparatus according to claim 16 , wherein the second voltage level is in a range of −5 kV to −30 kV.
18 . The plasma processing apparatus according to claim 13 , wherein the third voltage level has a negative polarity.
19 . The plasma processing apparatus according to claim 18 , wherein the second DC signal has the third voltage level during the third state.
20 . The plasma processing apparatus according to claim 19 , wherein the fourth voltage level is zero voltage level.