Plasma processing apparatus
Provided is a plasma processing apparatus capable of obtaining desired etch profiles and preventing the degradation of yield rates due to the adhesion of particles, and equipped with a processing chamber in which a sample is plasma-treated; a radio-frequency power source for supplying radio-frequency power used to generate plasma; a sample stage which is provided with electrodes for electrostatically adsorbing the sample and on which the sample is mounted; and a DC power supply for applying DC voltages to the electrodes, the apparatus being further equipped with a control apparatus for controlling the DC power supply so as to apply such DC voltages as to decrease the absolute value of the potential of the sample in the absence of the plasma.
1. A plasma processing apparatus comprising:
a processing chamber in which a sample is plasma-treated;
a radio-frequency power source for supplying radio-frequency power used to generate plasma;
a sample stage which is provided with electrodes for electrostatically adsorbing the sample and on which the sample is mounted;
a DC power supply for applying DC voltages to the electrodes; and
a controller which executes a sequence of programmed instructions to cause the controller to be configured to control the DC power supply so as to apply such DC voltages as to decrease the absolute value of the potential of the sample on the basis of a temperature of the sample stage or a difference of temperatures within the sample stage in the absence of the plasma,
wherein the controller is configured to control the DC power supply to maintain a potential of the sample stage to be 0 VDC between periods of plasma processing of the sample according to a stored relationship between coolant temperature values and resistance values.
2. A plasma processing apparatus comprising:
a processing chamber in which a sample is plasma-treated;
a radio-frequency power source for supplying radio-frequency power used to generate plasma;
a sample stage which is provided with electrodes for electrostatically adsorbing the sample and on which the sample is mounted and which includes a dielectric portion;
a DC power supply for applying DC voltages to the electrodes; and
a controller which executes a sequence of programmed instructions to cause the controller to be configured to control the DC power supply, when no plasma exists and the sample stage has a plurality of regions each of which is controlled to a different temperature,
wherein the controller is configured to control the DC voltages to decrease the absolute value of the potential of the sample on the basis of the different temperatures of the plurality of regions to correct the potential of the sample due to a change in coolant temperature based on a stored relationship between the coolant temperature and a resistance value of the dielectric portion of the sample stage, and
wherein the controller is further configured to control the DC power supply to maintain a potential of the sample stage to be 0 VDC between periods of plasma processing of the sample according to the stored relationship between the coolant temperature and the resistance value.
3. A plasma processing apparatus comprising:
a processing chamber in which a sample is plasma-treated;
a radio-frequency power source for supplying radio-frequency power used to generate plasma;
a sample stage which is provided with electrodes for electrostatically adsorbing the sample and on which the sample is mounted; and
a DC power supply for applying DC voltages to the electrodes; and
a controller which executes a sequence of programmed instructions to cause the controller to be configured to control the DC power supply, when no plasma exists and a first temperature of the sample stage in a step constituting plasma treatment conditions differs from a second temperature of the sample stage in a step following the plasma treatment step,
wherein the controller is configured to control the DC power supply to apply such DC voltages as to decrease the absolute value of the potential of the sample on the basis of the first temperature and the second temperature, and to maintain a potential of the sample stage to be 0 VDC in a step following the plasma treatment step according to a stored relationship between coolant temperature values and resistance values.
4. The plasma processing apparatus according to claim 2 ,
wherein if a first temperature of the sample stage in a step constituting plasma treatment conditions differs from a second temperature of the sample stage in a step following the plasma treatment step, the controller is further configured to control the DC power supply to apply the DC voltages to decrease the absolute value of the potential of the sample on the basis of the first temperature and the second temperature.