Methods for monitoring a flow controller coupled to a process chamber

Patent metadata

Field	Value
Publication number	US-9772629-B2
Application number	US-201213627659-A
Country	US
Kind code	B2
Filing date	Sep 26, 2012
Priority date	Sep 29, 2011
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

Methods and apparatus for in-situ calibration of a flow controller are provided herein. In some embodiments, a method of flowing a gas includes providing a flow controller configured to provide a first gas at a first value of a flow rate based on a calculated first relationship determined by using a standard gas; determining an actual first relationship between the flow rate and the setpoint for the first gas from a plurality of values of the flow rate of the first gas determined at a corresponding plurality of values of the setpoint of the flow controller, wherein each of the plurality of values of the flow rate is determined from flowing the first gas through the flow controller at corresponding ones of the plurality of values for the setpoint; and flowing the first gas at the first value of the flow rate based on the actual first relationship.

First claim

The invention claimed is:

1. A method of controlling a flow controller coupled to a process chamber, comprising:
monitoring, by a controller, at least one of a first zero offset of a flow controller at a first time or a first time during which the flow controller is in operation;
monitoring, by the controller, at least one of a second zero offset of the flow controller at a second time after the first time or a second time during which the flow controller is in operation;
issuing a service warning, via the controller, if either a cumulative zero drift exceeds about 10 percent of the full flow range of the flow controller, wherein the cumulative zero drift is the summation of the first zero offset and the second zero offset, or a cumulative operating lifetime exceeds a first critical value, wherein the cumulative operating lifetime is the summation of the first time and the second time; and
shutting down the flow controller automatically if the cumulative zero drift exceeds a critical value.

2. The method of claim 1 , wherein the critical value is about 20 percent of the full flow range of the flow controller.

3. The method of claim 1 , further comprising:
shutting down the flow controller if the cumulative operating time exceeds a second critical value.

4. The method of claim 1 , further comprising:
operating a flow controller to provide a flow of one or more gases to a process chamber over a period of time, wherein the monitoring of the first zero offset or the first time occurs after an initial calibration or an installation date of the flow controller prior to operating the flow controller.

5. A method of controlling a flow controller coupled to a process chamber, comprising:
monitoring, by a controller, a first value of at least one of a first parameter of the flow controller or a second parameter of the process chamber at a first flow rate of the flow controller at a first time while the flow controller is in operation;
monitoring, by a controller, a second value of the at least one of the first parameter of the flow controller or the second parameter of the process chamber at the first flow rate of the flow controller at a second time while the flow controller is in operation after the first time;
determining the status of at least one of the flow controller or a component of the process chamber, via the controller, from a comparison of the first and second values; and
setting the at least one of the first parameter of the flow controller or the second parameter of the process chamber to a new value based on the comparison and operating the flow controller and the process chamber with the at least one of the first or second parameters set at the new value.

6. The method of claim 5 , wherein the first parameter of the flow controller includes one or more of flow controller flow output, flow controller pressure output, flow controller temperature output, flow controller valve position, or total nitrogen equivalent flow output of the flow controller.

7. The method of claim 5 , wherein the second parameter of the process chamber includes one or more of chamber pressure or exhaust valve position.

8. The method of claim 5 , wherein determining the status of the flow controller includes determining if the flow controller is flowing high or low.

9. The method of claim 5 , wherein determining the status of the process chamber includes one or more of determining if a line pressure is increasing or decreasing, or determining if a line temperature is increasing or decreasing, wherein the line is disposed between the flow controller and a gas source from providing a gas from the gas source to the flow controller.

10. The method of claim 5 , wherein monitoring the first value further comprises:
monitoring the first values of a flow controller valve position, a total nitrogen equivalent flow of the flow controller, and an exhaust valve position of the process chamber at the first flow rate of the flow controller at the first time.

11. The method of claim 10 , wherein monitoring the second value further comprises:
monitoring the second values of the flow controller valve position, the total nitrogen equivalent flow of the flow controller, and the exhaust valve position of the process chamber at the first flow rate of the flow controller at the second time.

12. The method of claim 11 , wherein determining the status further comprises:
determining if the flow controller is flowing high or low from the comparison of the first and second values.

13. The method of claim 12 , determining that the flow controller is flowing high if the second values of each of the flow control valve position, the total nitrogen equivalent flow of the flow controller, and the exhaust valve position of the process chamber are higher than corresponding ones of the first values; or
determining that the flow controller is flowing low if the second values of each of the flow control valve position, the total nitrogen equivalent flow of the flow controller, and the exhaust valve position of the process chamber are lower than corresponding ones of the first values.

14. The method of claim 5 , wherein the first value is determined at the startup of a system including the flow controller and the process chamber; and wherein determining the status of at least one of the flow controller or a component of the process chamber comprises determining whether the flow controller continues to provide the first flow rate when the first parameter of the flow controller and the second parameter of the process chamber are set the same as at the first time.

Assignees

• Applied Materials Inc

Inventors

• Mohammed Balarabe N
• Lane John W
• Gregor Mariusch J
• Healy Dan Joseph

Classifications

• Y10T137/0324

  With control of flow by a condition or characteristic of a fluid · CPC title

• G05D7/0623 Primary

  characterised by the set value given to the control element · CPC title

• G01F25/0053

  Physics · mapped topic

• G01F25/15 Primary

  specially adapted for gas meters (G01F25/11 - G01F25/14, G01F25/17 take precedence) · CPC title