Vacuum processing apparatus and plasma processing apparatus with temperature control function for wafer stage
View Patent ↗A plasma processing apparatus includes a processing chamber, a wafer table, a refrigerant passage disposed inside the wafer table in which a refrigerant flows, a refrigeration cycle comprising the refrigerant passage in the wafer table as a first evaporator in which the refrigerant is evaporated as a result of a heat-exchange therein, a compressor, a condenser and an expansion valve, a second evaporator, and a controlling unit which adjusts a number of rotations of the compressor based upon a degree of dryness of the refrigerant at a position on the refrigeration cycle after passing through the first evaporation in a range in which dry-out does not occur in the first evaporator, and the dryness of the refrigerant being determined based upon an amount of a heat exchange during the evaporation of the refrigerant in the second evaporator.
1. A plasma processing apparatus comprising:
a processing chamber disposed inside a vacuum container in which a plasma is generated;
a wafer table disposed in the processing chamber on which a wafer to be processed by using the plasma is located;
a refrigerant passage disposed inside the wafer table in which a refrigerant flows;
a refrigeration cycle comprising the refrigerant passage in the wafer table as a first evaporator in which the refrigerant is evaporated as a result of a heat-exchange therein, a second evaporator disposed in an outside of the processing chamber, a compressor, a condenser and an expansion valve, wherein the first evaporator, the second evaporator, the compressor, the condenser, and the expansion valve are coupled and the refrigerant circulates in this order;
a heat exchange medium passage, a heat exchange medium provided in the heat exchange medium passage, the heat exchange medium being configured to exchange heat with the second evaporator,
wherein the second evaporator is disposed between the first evaporator and the compressor on the refrigeration cycle in which the refrigerant from the first evaporator flows, and the second evaporator is configured to evaporate the refrigerant in a liquid state flown out of the first evaporator using heat exchange with the heat exchange medium provided in the heat exchange medium passage; and
a controlling unit configured to adjust a flow rate of the refrigerant in the refrigerant cycle based upon a degree of dryness of the refrigerant at a position on the refrigeration cycle after passing through the first evaporator and before entering the second evaporator in a range in which the refrigerant at an exit of the first evaporator is maintained in a gas-liquid stage in a two-phase state of gas-liquid, the second evaporator evaporating the refrigerant in a liquid stage,
wherein the degree of dryness of the refrigerant is determined based upon a difference of temperatures of the heat exchange medium at a position of a supply side and at a position of a discharge side and a flow rate of the heat exchange medium, and a temperature and the flow rate of the refrigerant in the refrigeration cycle.
2. A plasma processing apparatus comprising:
a processing chamber disposed inside a vacuum container in which a plasma is generated;
a wafer table disposed in the processing chamber on which a wafer to be processed by using the plasma is located;
a refrigerant passage disposed inside the wafer table in which a refrigerant flows;
a refrigeration cycle comprising the refrigerant passage in the wafer table as a first evaporator in which the refrigerant is evaporated as a result of a heat-exchange therein, a second evaporator disposed in an outside of the processing chamber, a compressor, a condenser and an expansion valve, wherein the first evaporator, the second evaporator, the compressor, the condenser, and the expansion valve are coupled and the refrigerant circulates in this order;
a heat exchange medium passage, a heat exchange medium provided in the heat exchange medium passage, the heat exchange medium being configured to exchange heat with the second evaporator,
wherein the second evaporator is disposed between the first evaporator and the compressor on the refrigeration cycle in which the refrigerant from the first evaporator flows, and the second evaporator is configured to evaporate the refrigerant in a liquid state flown out of the first evaporator using heat exchange with the heat exchange medium provided in the heat exchange medium passage; and
a controlling unit configured to adjust a flow rate of the refrigerant in the refrigerant cycle based upon a degree of dryness of the refrigerant at a position on the refrigeration cycle after passing through the first evaporator and before entering the second evaporator in a range in which the refrigerant at an exit of the first evaporator is maintained in a gas-liquid stage in a two-phase state of gas-liquid, the second evaporator evaporating the refrigerant in a liquid stage,
wherein the degree of dryness of the refrigerant is determined based upon an amount of the heat exchange during the evaporation of the refrigerant in the second evaporator, and
wherein the degree of dryness of the refrigerant is determined based upon a difference of temperatures of the heat exchange medium at a position of a supply side and at a position of a discharge side and a flow rate of the heat exchange medium, and a temperature and the flow rate of the refrigerant in the refrigeration cycle.