Seasoning method and plasma processing apparatus
A seasoning method implemented in a plasma processing apparatus is provided. The plasma processing apparatus comprises a chamber and an electrostatic chuck, the electrostatic chuck including a central region which supports a substrate and an annular region which surrounds the central region and supports a ring assembly, the seasoning method includes: disposing the ring assembly on the annular region of the electrostatic chuck; disposing the substrate on the central region of the electrostatic chuck; forming a plasma in the chamber; calculating a thermal resistance between the electrostatic chuck and the ring assembly; and determining, based on the calculated thermal resistance, whether to repeat the forming the plasma and the calculating the thermal resistance.
1 . A plasma processing apparatus comprising:
a chamber;
an electrostatic chuck disposed in the chamber, the electrostatic chuck including a central region and an annular region, the central region supporting a substrate and the annular region surrounding the central region and supporting a ring assembly; and
a processor coupled to a memory storing instructions that, when executed by the processor, cause the processor to perform:
disposing the ring assembly on the annular region of the electrostatic chuck;
disposing the substrate on the central region of the electrostatic chuck;
forming a plasma in the chamber;
calculating a thermal resistance between the electrostatic chuck and the ring assembly;
repeating the forming the plasma and the calculating the thermal resistance; and
determining whether to further repeat the forming the plasma and the calculating the thermal resistance based on a difference between the thermal resistance after performing the forming the plasma and the calculating the thermal resistance n times and the thermal resistance after performing the forming the plasma and the calculating the thermal resistance n+1 times, wherein n is an integer of 1 or more.
2 . The plasma processing apparatus according to claim 1 , the instructions further cause the processor to perform repeating the forming the plasma and the calculating thermal resistance, based on a determination result in the determining whether to repeat, wherein the determining whether to repeat includes determining whether to further repeat the forming the plasma and the calculating the thermal resistance, based on a plurality of thermal resistances calculated by repeating the forming the plasma and the calculating the thermal resistance.
3 . The plasma processing apparatus according to claim 1 , wherein the instructions further cause the processor to perform: controlling supply power supplied to at least one heater so that a temperature of the at least one heater reaches setting temperature, the at least one heater being disposed in the electrostatic chuck; and measuring supply power supplied to the at least one heater with a plasma being formed in the chamber, and wherein in the calculating the thermal resistance, the thermal resistance is calculated based on the supply power measured with the plasma being formed in the chamber.
4 . The plasma processing apparatus according to claim 3 , wherein the instructions further cause the processor to perform measuring supply power supplied to the at least one heater with no plasma being formed in the chamber, and
wherein in the calculating the thermal resistance, the thermal resistance is calculated further based on the supply power measured with no plasma being formed in the chamber.
5 . The plasma processing apparatus according to claim 3 , wherein in the calculating the thermal resistance, at least one thermal resistance is calculated based on an equation expressing a relationship among (a) an amount of heat transferred from the plasma to the ring assembly, (b) a thermal resistance between the ring assembly and the at least one heater and (c) the supply power supplied to the at least one heater with the plasma being formed in the chamber.
6 . The plasma processing apparatus according to claim 3 ,
wherein with the plasma being formed in the chamber, a temperature of the ring assembly changes over time by a thermal flux generated between the plasma and the ring assembly.
7 . The plasma processing apparatus according to claim 1 , wherein the instructions further cause the processor to perform:
transferring with a transfer device, the ring assembly from outside the chamber to inside the chamber; and
disposing with the transfer device, the ring assembly on at least partially on the electrostatic chuck.
8 . The plasma processing apparatus according to claim 1 , wherein the annular region has a plurality of zones in a plan view of the annular region, and the instructions cause the processor to perform the calculating the thermal resistance for each of the plurality of zones.
9 . The plasma processing apparatus according to claim 3 , wherein the annular region has a plurality of zones in a plan view of the annular region, the at least one heater is disposed in each of the plurality of zones, and the instructions cause the processor to perform:
the calculating the thermal resistance for each of the plurality of zones;
controlling supply power for each of the plurality of zones; and
the measuring supply power for each of the plurality of zones.
10 . The plasma processing apparatus according to claim 9 , wherein at least one resistor is disposed, in the electrostatic chuck, in each of the plurality of zones, resistance of the at least one resistor varying with temperature, and the instructions cause the processor to perform the controlling supply power, in each of the plurality of zones, based on the resistance of the at least one resistor.
11 . The plasma processing apparatus according to claim 10 , wherein the at least one resistor is at least one thermistor.
12 . The plasma processing apparatus according to claim 10 , wherein, in the electrostatic chuck, the at least one heater is disposed between the ring assembly and the at least one resistor in each of the plurality of zones.
13 . The plasma processing apparatus according to claim 12 , wherein the at least one heater and the at least one resistor are at least partially overlapped in a plan view of the annular region.