Method for releasing sample and plasma processing apparatus using same
A sample releasing method for releasing a sample subjected to plasma processing from a sample stage on which the sample is electrostatically attracted by applying DC voltage to an electrostatic chuck electrode, and the method includes: moving the sample subjected to the plasma processing upward above the sample stage; and after moving the sample, controlling the DC voltage such that an electric potential of the sample is to be smaller.
1. A plasma processing apparatus comprising:
a processing chamber in which a sample is processed by using plasma;
a radio frequency power source which provides radio frequency power to generate the plasma;
a sample stage on which the sample is arranged, the sample stage having an electrode to electrostatically attract the sample;
a DC power source which applies DC voltage to the electrode;
a pin configured to lift the sample upward above the sample stage;
a conveyance mechanism; and
a controller having software and configured to:
move the pin to an upward position thereby lifting the sample above the sample stage while radio frequency power is provided, interrupt the radio frequency power from the radio frequency power source after moving the pin to an upward position, and while the pin is in the upward position, control an output value of the DC power source to apply, after a predetermined time from the interruption of the radio frequency power, a first predetermined voltage to the electrode by changeover from a second predetermined voltage, such that an absolute value of the second predetermined voltage is lower than an absolute value of the first predetermined voltage, control the conveyance mechanism to convey the sample outside the chamber while controlling the output value of the DC power source to apply the first predetermined voltage to the electrode, and after the sample is conveyed outside the chamber by the conveyance mechanism, control the output value of the DC power source to apply the second predetermined voltage.
2. A plasma processing apparatus comprising:
a processing chamber in which a sample is processed by using plasma;
a radio frequency power source which provides radio frequency power to generate the plasma;
a sample stage on which the sample is arranged, the sample stage having an electrode to electrostatically attract the sample;
a DC power source which applies DC voltage to the electrode;
a pin configured to lift the sample upward above the sample stage;
a conveyance mechanism; and
a control processor with software and constructed at least in part of hardware and configured to:
move the pin to an upward position thereby lifting the sample above the sample stage while radio frequency power is provided, interrupt the radio frequency power from the radio frequency power source after moving the pin to an upward position, and while the pin is in the upward position, control an output value of the DC power source to apply after a predetermined time from the interruption of the radio frequency power, a first predetermined voltage to the electrode by changeover from a second predetermined voltage, such that an absolute value of the second predetermined voltage is lower than an absolute value of the first predetermined voltage, control the conveyance mechanism to convey the sample outside the chamber while controlling the output value of the DC power source to apply the first predetermined voltage to the electrode, and after the sample is conveyed outside the chamber by the conveyance mechanism, control the output value of the DC power source to apply the second predetermined voltage.