Substrate processing apparatus and substrate processing method

1 . A substrate processing apparatus to etch a molybdenum film of a substrate having a device structure that includes, in a multistage manner, multilayer films including the molybdenum film, the apparatus comprising:

a processing tank that retains therein etchant including acetic acid, phosphoric acid, nitric acid, and water as components;

a supply unit that supplies acetic acid, phosphoric acid, nitric acid, and water individually or as the etchant to the processing tank;

an open/close valve that opens/closes a liquid discharging passage of the processing tank;

a concentration measuring unit that measures a concentration for each of the components of the etchant retained in the processing tank;

a liquid amount measuring unit that measures an amount of the etchant retained in the processing tank; and

a controller that controls the open/close valve and the supply unit to execute a discharging and replenishing process including:

discharging a part of the etchant from the processing tank; and

replenishing the processing tank with acetic acid, phosphoric acid, and nitric acid, wherein

in the discharging and replenishing process, the controller is configured to:

based on concentrations of the respective components measured by the concentration measuring unit, an amount of the etchant measured by the liquid amount measuring unit, a preliminarily-set target amount of the etchant, and preliminarily-set target concentrations of the respective components; decide a discharging amount of the etchant from the processing tank, and replenishing amounts of acetic acid, phosphoric acid, and nitric acid to the processing tank;

control the open/close valve to discharge the decided discharging amount of the etchant from the processing tank; and

control the supply unit to replenish the processing tank with the decided replenishing amounts of acetic acid, phosphoric acid, and nitric acid.

2 . The substrate processing apparatus according to claim 1 , wherein

the controller is further configured to:

in a case where a moisture concentration measured by the concentration measuring unit exceeds a threshold, execute the discharging and replenishing process.

3 . The substrate processing apparatus according to claim 1 , wherein

the controller is further configured to:

control the supply unit to execute:

a liquid replacement process for supplying the etchant whose moisture concentration is lower than the target concentration to the processing tank; and

a concentration adjusting process for adjusting a concentration of the etchant after the liquid replacement process, and

in the concentration adjusting process, the controller is further configured to:

based on concentrations of the respective components measured by the concentration measuring unit, an amount of the etchant measured by the liquid amount measuring unit, a target amount of the etchant, and target concentrations of the respective components; decide replenishing amounts of acetic acid, phosphoric acid, nitric acid, and water to the processing tank; and

control the supply unit to supply the decided replenishing amounts of acetic acid, phosphoric acid, nitric acid, and water to the processing tank.

4 . The substrate processing apparatus according to claim 1 , wherein

the supply unit includes:

an individual supply unit that individually supplies acetic acid, phosphoric acid, nitric acid, and water to the processing tank; and

an etchant supplying unit that supplies the etchant to the processing tank, and

the individual supply unit includes:

a first acetic acid supply unit that supplies acetic acid at a first flow volume; and

a second acetic acid supplying unit that supplies acetic acid at a second flow volume that is larger than the first flow volume.

5 . The substrate processing apparatus according to claim 4 , wherein

the second acetic acid supplying unit includes a flow volume adjusting valve.

6 . The substrate processing apparatus according to claim 4 , wherein

the etchant supplying unit includes a flow volume adjusting valve.

7 . The substrate processing apparatus according to claim 1 , wherein

the supply unit includes a temperature regulating unit that adjusts temperatures of acetic acid, phosphoric acid, nitric acid, and water, and

the controller is further configured to:

control the temperature regulating unit to adjust temperatures of acetic acid, phosphoric acid, nitric acid, and water to equal to or more than 10° C. and equal to or less than 40° C.

8 . A substrate processing method for etching a molybdenum film of a substrate having a device structure that includes, in a multistage manner, multilayer films including the molybdenum film, the method comprising:

measuring concentrations of respective components in etchant retained in a processing tank, the etchant including acetic acid, phosphoric acid, nitric acid, and water as the components;

measuring an amount of the etchant retained in the processing tank;

discharging a part of the etchant from the processing tank; and

executing a discharging and replenishing process for replenishing the processing tank with acetic acid, phosphoric acid, and nitric acid, wherein

the executing the discharging and replenishing process includes:

based on concentrations of the respective components measured in the measuring concentrations, an amount of the etchant measured in the measuring an amount of the etchant, a preliminarily-set target amount of the etchant, and preliminarily-set target concentrations of the respective components; deciding a discharging amount of the etchant from the processing tank and replenishing amounts of acetic acid, phosphoric acid, and nitric acid to the processing tank;

discharging the decided discharging amount of the etchant from the processing tank; and

supplying the decided replenishing amounts of acetic acid, phosphoric acid, and nitric acid to the processing tank.