Plasma etching apparatus and control method

1. A control method comprising:

a first processing step of controlling a temperature of a base to a first temperature, controlling a temperature of an electrostatic chuck that is disposed on the base so as to mount thereon an object to be processed and has a heater installed therein to a second temperature, and performing first processing on the object; and

a second processing step of controlling a temperature of the base to a third temperature, controlling a temperature of the electrostatic chuck to a fourth temperature by a heater, and performing second processing on the object,

wherein a difference between the first temperature and the second temperature and a difference between the third temperature and the fourth temperature are within a tolerable temperature of the junction layer for bonding the base and the electrostatic chuck.

2. The control method of claim 1 , further comprising, after the first processing step, a changing step of changing, when a difference between the first temperature and the fourth temperature exceeds the tolerable temperature of the junction layer, the first temperature to the third temperature so that the temperature difference with respect to the fourth temperature becomes within the tolerable temperature range of the junction layer.

3. The control method of claim 1 , wherein a cooling medium circulates in a flow path disposed in the base by a chiller, and the temperature of the base is controlled by controlling the temperature of the cooling medium.

4. The control method of claim 3 , wherein the cooling medium circulates in the flow path disposed in the base by the chiller; the chiller circulates the cooling medium by sending the cooling medium to an inlet of the flow path disposed in the base, receiving the cooling medium output from an outlet of the flow path, controlling the temperature of the cooling medium, and then sending the cooling medium to the flow path; and in the changing step, the temperature of the cooling medium output from the outlet of the flow path is measured and the temperature of the cooling medium to be sent to the inlet of the flow path is controlled based on the measured temperature of the cooling medium.

5. The control method of claim 1 , wherein in the case of increasing the temperature of the electrostatic chuck by the heater, in the changing step, the first temperature is changed to the third temperature before the second temperature is started to be increased to the fourth temperature.

6. The control method of claim 1 , wherein in the case of decreasing the temperature of the electrostatic chuck by the heater, in the changing step, the first temperature is changed to the third temperature after the second temperature is started to be decreased to the fourth temperature.

7. The control method of claim 3 , wherein the chiller for controlling the temperature of the base has a low temperature control unit and a high temperature control unit, and a coolant from any one of the low temperature control unit and the high temperature control unit is made to flow in the flow path during the temperature control of the base.

8. The control method of claim 3 , further comprising a step of stopping the circulation of the coolant in the base in a changing step of changing the first temperature to the third temperature, after the first processing, so that the temperature difference with respect to the fourth temperature becomes within the tolerable temperature range of the junction layer when the difference between the first temperature and the fourth temperature exceeds the tolerable temperature of the junction layer.

9. A plasma etching apparatus comprising:

a base;

an electrostatic chuck disposed on the base and configured to mount thereon an object to be processed;

a junction layer bonding the base and the electrostatic chuck;

a heater provided in the electrostatic chuck;

a chiller configured to control a temperature of the base; and

a control unit configured to control, when first processing is performed on the object, a temperature of the base to a first temperature and a temperature of the electrostatic chuck to a second temperature, and control, when second processing is performed on the object, a temperature of the base to a third temperature and a temperature of the electrostatic chuck to a fourth temperature by the heater,

wherein a temperature difference between the first temperature and the second temperature and a temperature difference between the third temperature and the fourth temperature are within a tolerable temperature of the junction layer.

10. The plasma etching apparatus of claim 9 , wherein, when the temperature between the first temperature and the fourth temperature exceeds the tolerable temperature of the junction layer, the control unit changes, after the first processing, the first temperature to the third temperature so that the temperature difference with respect to the fourth temperature becomes within the tolerable temperature of the junction layer.

11. The plasma etching apparatus of claim 9 , wherein a cooling medium circulates in the flow path provided in a base by the chiller, and the temperature of the base is controlled by controlling the temperature of the cooling medium.

12. The plasma etching apparatus of claim 9 , wherein a cooling medium circulates in the flow path disposed in a base by the chiller;

the chiller circulates the cooling medium by sending the cooling medium to an inlet of the flow path disposed in the base, receiving the cooling medium output from an outlet of the flow path, controlling the temperature of the cooling medium, and then sending the cooling medium to the flow path;

the plasma etching apparatus further comprises a measurement unit configured to measure the temperature of the cooling medium output from the outlet of the flow path; and

the control unit controls the temperature of the cooling medium to be sent to the inlet of the flow path based on the temperature of the cooling medium which is measured by the measurement unit.

13. The plasma etching apparatus of claim 9 , wherein in the case of increasing the temperature of the electrostatic chuck by the heater, the control unit changes the first temperature to the third temperature before the second temperature is started to be increased to the fourth temperature.

14. The plasma etching apparatus of claim 9 , wherein, in the case of decreasing the temperature of the electrostatic chuck by the heater, the control unit changes the first temperature to the third temperature before the second temperature is started to be decreased to the fourth temperature.

15. The plasma etching apparatus of claim 9 , wherein the chiller for controlling the temperature of the base has a low temperature control unit and a high temperature control unit, and a coolant from any one of the low temperature control unit or the high temperature control unit is made to flow in the flow path during the temperature control of the base.

16. The control method of claim 9 , wherein the control unit stops circulation of a coolant in the base, in case of changing the first temperature to the third temperature, after the first processing, so that the temperature difference with respect to the fourth temperature becomes within the tolerable temperature of the junction layer when the difference between the first temperature and the fourth temperature exceeds the tolerable temperature of the junction layer.