Gas supply system, plasma processing apparatus, and control method for gas supply system

Patent metadata

Field	Value
Publication number	US-11217432-B2
Application number	US-201916979793-A
Country	US
Kind code	B2
Filing date	Jun 18, 2019
Priority date	Jul 2, 2018
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

When a gas supplied to a gas injection unit is switched from a first processing gas to a second processing gas, a controller of a gas supply system performs control to open a first supply on/off valve connected to the gas injection unit and provided in a first gas supply line for supplying the first processing gas and a second exhaust on/off valve provided in a first gas exhaust line branched from the first gas supply line, close a second supply on/off valve connected to the gas injection unit and provided in a second gas supply line for supplying the second processing gas and a first exhaust on/off valve provided in a second gas exhaust line branched from the second gas supply line; and then open the second supply on/off valve and the first exhaust on/off valve and close the first supply on/off valve and the second exhaust on/off valve.

First claim

The invention claimed is:

1. A gas supply system comprising:
a gas injection unit that is disposed to face a substrate support on which a target object is to be placed and configured to inject a gas from a plurality of gas injection holes formed on a facing surface of the gas injection unit that faces the substrate support;
a first gas supply line that is connected to the gas injection unit and configured to supply a first processing gas;
a second gas supply line that is connected to the gas injection unit and configured to supply a second processing gas;
a first gas exhaust line that is branched from the first gas supply line and configured to exhaust the first processing gas flowing through the first gas supply line to a gas exhaust mechanism;
a second gas exhaust line that is branched from the second gas supply line and configured to exhaust the second processing gas flowing through the second gas supply line to the gas exhaust mechanism;
a first supply on/off valve that is disposed at a downstream side of a branch point of the first gas supply line where the first gas exhaust line is branched and configured to switch an ON/OFF state of the first gas supply line;
a second supply on/off valve that is disposed at a downstream side of a branch point of the second gas supply line where the second gas exhaust line is branched and configured to switch an ON/OFF state of the second gas supply line;
a first exhaust on/off valve configured to switch an ON/OFF state of the first gas exhaust line;
a second exhaust on/off valve configured to switch an ON/OFF state of the second gas exhaust line; and
a controller configured to control the first supply on/off valve and the second exhaust on/off valve to be in an open state and the second supply on/off valve and the first exhaust on/off valve to be in a closed state, and then control the second supply on/off valve and the first exhaust on/off valve to be in an open state and the first supply on/off valve and the second exhaust on/off valve to be in a closed state when the gas supplied to the gas injection unit is switched from the first processing gas to the second processing gas, and
control the second supply on/off valve and the first exhaust on/off valve to be in the open state and the first supply on/off valve and the second exhaust on/off valve to be in the closed state, and then control the first supply on/off valve and the second exhaust on/off valve to be in the open state and the second supply on/off valve and the first exhaust on/off valve to be in the closed state when the gas supplied to the gas injection unit is switched from the second processing gas to the first processing gas.

2. The gas supply system of claim 1 , wherein when the gas supplied to the gas injection unit is switched from the first processing gas to the second processing gas, the controller switches the second supply on/off valve from the closed state to the open state after switching the first supply on/off valve from the open state to the closed state, and
when the gas supplied to the gas injection unit is switched from the second processing gas to the first processing gas, the controller switches the first supply on/off valve from the closed state to the open state after switching the second supply on/off valve from the open state to the closed state.

3. The gas supply system of claim 1 , wherein the first gas supply line is connected to the gas injection unit at a downstream side of the first supply on/off valve and the second gas supply line is connected to the gas injection unit at a downstream side of the second supply on/off valve through a first common line having a first pressure gauge,
the first gas exhaust line is connected to the gas exhaust mechanism at a downstream side of the first exhaust on/off valve and the second gas exhaust line is connected to the gas exhaust mechanism at a downstream side of the second exhaust on/off valve through a second common line having a second pressure gauge,
the second common line is provided with an exhaust flow rate control valve, which is configured to adjust an opening degree thereof, at a downstream side of the second pressure gauge,
the first gas supply line is provided with a first supply flow rate control valve, which is configured to adjust an opening degree thereof, at an upstream side of the branch point where the first gas exhaust line is branched, and
the second gas supply line is provided with a second supply flow rate control valve, which is configured to adjust an opening degree thereof, at an upstream side of the branch point where the second gas exhaust line is branched,
wherein when the gas supplied to the gas injection unit is switched from the first processing gas to the second processing gas, the controller controls the opening degree of the exhaust flow rate control valve to correspond to a conductance when the gas is injected from the gas injection unit, and the opening degree of the second supply flow rate control valve so that a pressure of the second pressure gauge becomes a pressure corresponding to a flow rate of the second processing gas and, thereafter,
the controller controls the opening degree of the exhaust flow rate control valve to close the exhaust flow rate control valve or adjust the opening degree of the exhaust flow rate control valve to a small degree and, then, when the pressure of the second pressure gauge becomes equal to or higher than a pressure of the first pressure gauge, the controller switches the first supply on/off valve from the open state to the closed state and switches the second supply on/off valve from the closed state to the open state, and
wherein when the gas supplied to the gas injection unit is switched from the second processing gas to the first processing gas, the controller controls the opening degree of the exhaust flow rate control valve to correspond to a conductance when the gas is injected from the gas injection unit, and the opening degree of the first supply flow rate control valve so that a pressure of the second pressure gauge becomes a pressure corresponding to a flow rate of the first processing gas and, thereafter,
the controller controls the opening degree of the exhaust flow rate control valve to close the exhaust flow rate control valve or adjust the opening degree of the exhaust flow rate control valve to a small degree and, then, when the pressure of the second pressure gauge becomes equal to or higher than a pressure of the first pressure gauge, the controller switches the second supply on/off valve from the open state to the closed state and switches the first supply on/off valve from the closed state to the open state.

4. The gas supply system of claim 1 , wherein an inner space of the gas injection unit is divided into a plurality of spaces, the respective spaces communicate with the gas injection holes so that the gas supplied to each of the spaces is injected from the gas injection holes communicating with the corresponding space, and
the first gas supply line, the second gas supply line, the first gas exhaust line, the second gas exhaust line, the first supply on/off valve, the second supply on/off valve, the first exhaust on/off valve, and the second exhaust on/off valve are provided for each of the spaces of the gas injection unit.

5. The gas supply system of claim 4 , wherein the controller obtains pressures of the first processing gas or the second processing gas respectively corresponding to flow rates of the processing gas supplied to the spaces of the gas injection unit based on characteristic data indicating a relationship between the flow rate and the pressure of the processing gas, and
the controller controls so that the processing gas is split to the spaces of the gas injection unit at the obtained pressure ratio of the processing gas.

Assignees

• Tokyo Electron Ltd

Inventors

• Sawachi Atsushi

Classifications

• H10P72/0421 Primary

  for drying etching · CPC title

• H10P50/242

  of Group IV materials · CPC title

• H10P14/60

  of insulating materials · CPC title

• H01J37/32449 Primary

  Gas control, e.g. control of the gas flow · CPC title

• C23C16/45544

  characterized by the apparatus · CPC title