Plasma processing method and plasma processing device
Controllability of ion bombardment on a substrate is further improved to achieve uniformity of the etched substrate across the substrate surface. A plasma processing apparatus performs plasma generation and control of energy of ion bombardment on the substrate independently, generates plasma by continuous discharge or pulse discharge, and switches at least two bias powers having different frequencies, and alternately and repeatedly applies the at least two bias powers having different frequencies to a sample stage while the plasma is being generated.
1. A plasma processing method for processing, using plasma, a sample mounted on a sample stage, the method comprising:
supplying a first RF power and a second RF power to the sample stage through a filter, which includes a first filter and a second filter, while periodically switching between the first RF power provided by a first RF power source and the second RF power provided by a second RF power source using the first filter and the second filter,
wherein the first filter passes the first RF power of a first frequency and does not pass the second RF power of a second frequency,
wherein the second filter passes the second RF power of the second frequency and does not pass the first RF power of the first frequency, and
wherein the first frequency is higher than the second frequency.
2. The plasma processing method according to claim 1 , wherein the first RF power and the second RF power are combined when switching between the first RF power and the second RF power.
3. The plasma processing method according to claim 1 , wherein the first RF power or the second RF power is on-off modulated.
4. The plasma processing method according to claim 1 , wherein
an RF power for generating the plasma, the first RF power, and the second RF power are on-off modulated,
a time duration of supply of the first RF power to the sample stage and a time duration of supply of the second RF power to the sample stage are identical, and
a cycle time of the on-off modulation of the RF power, a cycle time of the on-off modulation of the first RF power, and a cycle time of the on-off modulation of the second RF power are identical.
5. The plasma processing method according to claim 1 , wherein an output voltage of the first RF power and an output voltage of the second RF power differ from each other.
6. The plasma processing method according to claim 5 , wherein the output voltage of the first RF power is smaller than the output voltage of the second RF power.
7. The plasma processing method according to claim 1 , wherein
a third RF power for generating the plasma, the first RF power, and the second RF power are on-off modulated, and
a sum of on-time duration of the on-off modulated first RF power and one cycle time of the on-off modulated second RF power is equal to an on-time duration of the on-off modulated third RF power.
8. The plasma processing method according to claim 1 , wherein
a third RF power for generating the plasma is on-off modulated,
a sum of time duration of supply of the first RF power to the sample stage and a time duration of supply of the second RF power to the sample stage is equal to an on-time duration of the on-off modulated third RF power, and
a time of not supplying the first RF power and the second RF power to the sample stage is equal to the off-time duration of the on-off modulated third RF power.
9. The plasma processing method according to claim 8 , wherein
the first RF power and the second RF power are on-off modulated.