Method and apparatus for using a pressure control system to monitor a plasma processing system

• US 20050283321A1
• Filed: 06/16/2004
• Published: 12/22/2005
• Est. Priority Date: 06/16/2004
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Lam, Hieu A., Yue, Hongyu
• Granted Patent: US 7,430,496 B2
• Time in Patent Office: Days
• US Class Current: 702/30
• CPC Class Codes: H01J 37/32623 Mechanical discharge control means
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge

Abstract

A method and apparatus is presented for using a pressure control system to monitor a plasma processing system. By monitoring variations in the state of the pressure control system, a fault condition, an erroneous fault condition, or a service condition can be detected. For example, the service condition can include monitoring the accumulation of residue between successive preventative maintenance events.

Claims

1. A method of determining a status for a plasma processing system comprising:

executing a process in said plasma processing system;

monitoring a pressure control system, coupled to said plasma processing system, configured to control the pressure of said process in said plasma processing system; and

determining at least one of a fault condition, an erroneous fault condition, or a service condition for said plasma processing system from said monitoring.

2. The method of claim 1, wherein said process comprises an etch process.

3. The method of claim 1, wherein said monitoring said pressure control system includes monitoring a position of a valve.

4. The method of claim 3, wherein said valve is selected from a group comprising a gate valve, a swing gate valve, and a butterfly valve.

5. The method of claim 3, wherein said monitoring said position of said valve includes monitoring a valve angle of said valve.

6. The method of claim 3, wherein said monitoring said position of said valve includes monitoring at least one of a change in said position of said valve, or a rate of change in said position of said valve.

7. The method of claim 6, wherein said determining at least one of said fault condition, said erroneous fault condition, or said service condition further comprises monitoring a parameter associated with said pressure control system, setting a threshold for an acceptable change to said parameter, and comparing a monitored change in said parameter with said threshold for acceptable change.

8. The method of claim 7, wherein determining said fault condition occurs when at least one of said change in said position of said valve or said rate of change of said position of said valve exceeds a pre-determined threshold.

9. The method of claim 1, wherein said determining said fault condition includes monitoring a parameter associated with said pressure control system and correlating a change in said parameter with said fault condition.

10. The method of claim 1, wherein said determining said erroneous fault condition includes monitoring a first parameter associated with said pressure control system, and correlating an insubstantial change in said first parameter with a substantial change in a second parameter associated with a gas injection system coupled to said plasma processing system and configured to introduce a process gas to said plasma processing system.

11. The method of claim 1, wherein said determining said service condition includes monitoring a parameter associated with said pressure control system and correlating a substantially gradual change in said parameter with an accumulation of residue on an interior surface of said plasma processing system.

12. The method of claim 1, wherein said monitoring said pressure control system includes monitoring a pumping system.

13. A plasma processing system comprising:

a process chamber;

a plasma source coupled to said process chamber and configured to form a plasma in said process chamber;

a substrate holder disposed within said process chamber and configured to support a substrate;

a gas injection system coupled to said process chamber and configured to introduce a process gas;

a pressure control system coupled to said process chamber and configured to control a pressure in said process chamber; and

a controller coupled to said plasma processing system and configured to monitor said pressure control system and determine at least one of a fault condition, an erroneous fault condition, or a service condition for said plasma processing system from said monitoring according to any one of claims 1-12.