Patent ID: 8034181
Filing Date: 2011-10-11
Classification: H01J,H01L

Abstract:
1. A plasma processing apparatus comprising: a processing chamber encased in a vacuum vessel equipped with an evacuator, the processing chamber being configured to process a sample located therein using a plasma generated in the processing chamber; a sample stage located in the processing chamber and having an upper surface on which the sample to be processed is located; a gas feeding unit for feeding processing gas into the processing chamber; a plurality of liquid refrigerant ducts which have different cooling capacities are disposed internally of the sample stage, liquid refrigerant being provided through the plurality of refrigerant ducts and being evaporated by heat generated internally of the sample stage during processing of the sample, one of the plurality of liquid refrigerant ducts having a first cooling capacity being disposed at a first distance between an inner wall thereof and the upper surface of the sample stage and another of the plurality of liquid refrigerant ducts having a second cooling capacity which is lower than the first cooling capacity being disposed at a second distance between an inner wall of the another of the plurality of liquid refrigerant ducts and the upper surface of the sample stage which is larger than the first distance so that the one and the another of the plurality of liquid refrigerant ducts are disposed substantially in parallel within the sample stage and are interconnected through a down flow opening, and the liquid refrigerant being selectively flown into the one and the another of the plurality of liquid refrigerant ducts; a cooling circuit mainly including the plurality of liquid refrigerant ducts, a compressor, a condenser, an expansion valve, and a set of pipelines which connect the compressor, the condenser, the expansion valve and the plurality of liquid refrigerant ducts in this order, the liquid refrigerant flows in this order along the set of pipelines and circulates in the cooling circuit, and the set of pipelines of the cooling circuit including two parallel installed lines of the liquid refrigerant which are branched on an upstream side of the plurality of liquid refrigerant ducts and connect respectively to the one and the another of the plurality of liquid refrigerant ducts, and one line at which a downstream side of the one and the another of the plurality of liquid refrigerant ducts are interconnected through the down flow opening; a selecting unit which selects one of the two parallel installed lines for the liquid refrigerant to flow the liquid refrigerant through the selected one parallel installed line; and a control unit which sends a command of selecting the one of the two parallel installed lines for flowing the liquid refrigerant therethrough to the selecting unit and adjusts at least one of a flow rate and a pressure of the liquid refrigerant flowing into one of the one and the another of the plurality of liquid refrigerant ducts corresponding to the selected one of the two parallel installed lines; wherein the sample is processed by using plasma generated within the processing chamber while a temperature of the sample stage is controlled by the liquid refrigerant flowing through the cooling circuit and the one of the one and the another of the plurality of liquid refrigerant ducts.