Method and apparatus for plasma processing
View Patent ↗The present invention provides a plasma processing method that uses a plasma processing apparatus including a plasma processing chamber in which a sample is plasma processed, a first radio-frequency power supply that supplies a first radio-frequency power for generating plasma, and a second radio-frequency power supply that supplies a second radio-frequency power to a sample stage on which the sample is mounted, wherein the plasma processing method includes the steps of modulating the first radio-frequency power by a first pulse; and controlling a plasma dissociation state to create a desired dissociation state by gradually controlling a duty ratio of the first pulse as a plasma processing time elapses.
1. A plasma processing method that uses a plasma processing apparatus comprising a plasma processing chamber in which a sample is plasma processed, a first radio-frequency power supply that supplies a first radio-frequency power for generating plasma, and a second radio-frequency power supply that supplies a second radio-frequency power to a sample stage on which the sample is mounted, said plasma processing method comprising the steps of:
modulating the first radio-frequency power by a first pulse; and
controlling a plasma dissociation state to create a desired dissociation state by gradually controlling a duty ratio of the first pulse as a plasma processing time elapses.
2. The plasma processing method according to claim 1 , wherein
the duty ratio is controlled based on an etching profile of the sample.
3. The plasma processing method according to claim 1 , wherein
the first radio-frequency power in an on period of the pulse is a power that can stably generate plasma.
4. The plasma processing method according to claim 1 , further comprising the step of:
modulating the second radio-frequency power by a second pulse, wherein
the first pulse is also in an on period during an on period of the second pulse.
5. The plasma processing method according to claim 1 , further comprising the steps of:
modulating the second radio-frequency power by a second pulse;
gradually decreasing the duty ratio of the first pulse as the plasma processing time elapses; and
gradually increasing a duty ratio of the second pulse as the plasma processing time elapses.
6. The plasma processing method according to claim 1 , further comprising the steps of:
modulating the second radio-frequency power by a second pulse;
gradually increasing the duty ratio of the first pulse as the plasma processing time elapses; and
gradually decreasing a duty ratio of the second pulse as the plasma processing time elapses.
7. The plasma processing method according to claim 1 , wherein
the duty ratio is controlled by changing an off period with an on period of the first pulse kept constant.
8. The plasma processing method according to claim 1 , wherein
the duty ratio is controlled by changing an on period with an off period of the first pulse kept constant.
9. A plasma processing method according to claim 1 , wherein
the plasma is generated using one of a mixed gas of CHF 3 gas, CO gas, and H 2 gas, a mixed gas of CHF 3 gas, CO 2 gas, and H 2 gas, a mixed gas of C 2 F 6 gas, CO gas, and H 2 gas, and a mixed gas of C 2 F 6 gas, CO 2 gas, and H 2 gas.
10. A plasma processing method that uses a plasma processing apparatus comprising a plasma processing chamber in which a sample is plasma processed, a first radio-frequency power supply that supplies a first radio-frequency power for generating plasma, and a second radio-frequency power supply that supplies a second radio-frequency power to a sample stage on which the sample is mounted, said plasma processing method comprising the steps of:
modulating the first radio-frequency power by a first pulse; and
controlling a plasma dissociation state to create a desired dissociation state by controlling a duty ratio of the first pulse based on an etching depth of the sample or a plasma impedance.