Method for supplying gas, and plasma processing apparatus

Abstract

In the exemplary embodiment, a method for supplying a gas is provided. This method includes: supplying a processing gas to each of a central gas inlet portion and a peripheral gas inlet portion through a first branch line and a second branch line; closing a valve at a downstream side in a gas line for an additional gas, and filling the additional gas in a tube between the valve and an upstream flow rate controller; opening the valve after filling the additional gas, and supplying a high frequency power to one of an upper electrode and a lower electrode from a high frequency power supply after opening the valve.

What is claimed is: 
     
         1 . A plasma processing apparatus configured to process a processing target object, the plasma processing apparatus comprising:
 a processing container;   a mounting stage provided within the processing container to constitute a lower electrode;   a shower head provided above the mounting stage to constitute an upper electrode;   a high frequency power supply configured to supply a high frequency power to one of the upper electrode and the lower electrode;   a gas supply system configured to supply a processing gas and an additional gas to the shower head; and   a controller,   wherein the shower head includes a central gas inlet portion facing a central region of the mounting stage, and a peripheral gas inlet portion facing a region outside the central region of the mounting stage,   the gas supply system includes:
 a first gas source configured to supply the processing gas; 
 a second gas source configured to supply the additional gas; 
 a first branch line and a second branch line configured to supply the processing gas from the first gas source, to the central gas inlet portion and the peripheral gas inlet portion, respectively; and 
 a gas line connecting the second gas source to the second branch line and including a flow rate controller, a valve provided between the flow rate controller and the second branch line, and a tube provided between the flow rate controller and the valve, and 
   the controller executes:   a first control to supply the processing gas to each of the central gas inlet portion and the peripheral gas inlet portion through the first branch line and the second branch line,   a second control to fill the additional gas in the tube by closing the valve,   a third control to open the valve after the additional gas is filled, and   a fourth control to supply the high frequency power to one of the upper electrode and the lower electrode from the high frequency power supply after the valve is opened.