Apparatus and methods for monitoring health of semiconductor process systems

• US 8,055,370 B1
• Filed: 06/23/2006
• Issued: 11/08/2011
• Est. Priority Date: 06/23/2006
• Status: Active Grant

• Current Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Original Assignee: Novellus Systems Incorporated (Lam Research Corporation)
• Inventors: Jain, Jaideep, Fleming, Russell, Achtnig, Jeffery William
• Primary Examiner(s): DeCady; Albert
• Assistant Examiner(s): NORTON, JENNIFER L
• Application Number:
  US11/473,890
• Time in Patent Office: 1,964 Days
• Field of Search: 700/9, 700/19, 700/32, 700/72, 700/108, 700/109, 700/121, 340/3.1, 702/57, 702/89, 702/176
• US Class Current: 700/108
• CPC Class Codes: G05B 19/41875 characterised by quality surveillance of production
• CPC Class Codes: G05B 23/0232 based on qualitative trend analysis, e.g. system evolution
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

Disclosed are apparatus and methods for monitoring an operation parameter of a process tool, independently of a process system recipe, are provided. In general, an indirect effect that results from implementing an event from a process system recipe on the process system is monitored without using the specific values or setpoints that are entered for such event into the process system to thereby change a state of such process system. In one embodiment, the behavior of a process device as it transitions between different states is monitored for a single cycle of operation or over time to detect trends that indicate a potential failure of the process device. When a trend that indicates a potential failure is detected, an alarm is generated. In one implementation, the time for reaching a particular stage of operation may be repeatedly monitored over a plurality of device cycles. For example, the time to open a valve or door may be monitored. In another example, the time for reaching a stable phase of gas flow after a ramping stage has commenced is monitored. When the time for reaching a particular stage begins to decline by a predetermined amount, an alarm may be generated.

Claims

1. A method of monitoring a process system for performing a fabrication operation on a semiconductor wafer, the method comprising:

receiving at a monitoring system feedback specifying a delay in a change in state of a characteristic of a component of the process system after entering of input data or a setpoint to cause the change in state of the component, wherein the specified delay occurs during a fabrication operation on the semiconductor wafer;

determining at the monitoring system whether there is an actual or imminent problem with operation of the component based on a timing analysis of the feedback from such component so as to determine whether there is a timing trend in the delay for the change in state that indicates an actual or imminent problem, wherein such determination is accomplished without analysis of the input data or setpoint that was entered for such component; and

reporting the actual or imminent problem or sending an alert regarding the actual or imminent problem when it is determined that there is an actual or imminent problem.

2. A method as recited in claim 1, wherein the component is a valve of the process system, the feedback specifies the delay for transitioning between an open and closed state and it is determined that there is an actual or imminent problem when such delay is greater than a predetermined duration.

3. A method as recited in claim 1, wherein the component is a mass flow controller (MFC) or a unit pressure controller (UPC) of the process system, the feedback specifies the delay for transitioning between an idle and stable state and it is determined that there is an actual or imminent problem when such delay is greater than a predetermined duration.

4. A method as recited in claim 1, wherein the component is a radio frequency (RF) generator of the process system, the feedback specifies the delay for transitioning between an on and off state and it is determined that there is an actual or imminent problem when such delay is greater than a predetermined duration.

5. A method as recited in claim 1, wherein the component is an RF generator of the process system, the feedback specifies the delay for transitioning between an on and off state and it is determined that there is an actual or imminent problem when a rate of change of such delay over time is greater than a predetermined amount.

6. A method as recited in claim 1, wherein an alert regarding the actual or imminent problem is sent when it is determined that there is an actual or imminent problem, the method further comprising:

after an alert is sent, scheduling shutdown of the process system and re-routing wafers to another process system; and

examining the process system to determine a cause of the problem.

7. A method as recited in claim 1, wherein determining whether there is an actual or imminent problem is accomplished by correlating the feedback with feedback from one or more other components to thereby predict failure is likely to occur under a set of conditions of the current and one or more other components.

8. A method as recited in claim 1, wherein the delay is a delay in a change in state of an RF power level or DC power level output and the determination is based on such output without being based on a RF or DC power level input to the component.

9. A method as recited in claim 1, wherein the delay is a delay in a change in state of a flow level output and the determination is based on such output without being based on a flow level setpoint input to the component.

10. A method as recited in claim 1, wherein the delay is a delay in a change in state of a rotational speed.

11. A method as recited in claim 1, wherein the delay is a delay in a change in state of a voltage output.

24. A method as recited in claim 1, wherein the feedback specifies a delay in a change in state of a characteristic of a component of the process system after entering of input data to cause the change in state of the component so as to result in a setpoint value for the component and wherein output of the setpoint value is disabled so that the setpoint value remains as part of a recipe within the process system.

26. A method as recited in claim 1, further comprising comparing the delay in the feedback to an expected delay in a change in state of the characteristic of the component of the process system after entering of input data or the setpoint and during the fabrication operation, wherein it is determined whether there is an actual or imminent problem when the comparison results in a significant difference.

12. An apparatus for monitoring a process system for performing a fabrication operation on a semiconductor wafer, comprising:

one or more processors;

one or more memory, wherein at least one of the processors and memory are operable for performing the following operations;

receiving feedback specifying a delay in a change in state of a characteristic of a component of the process system after entering of input data or a setpoint to cause the change in state of the component, wherein the specified delay occurs during a fabrication operation on the semiconductor wafer;

determining whether there is an actual or imminent problem with operation of the component based on a timing analysis of the feedback from such component so as to determine whether there is a timing trend in the delay for the change in state that indicates an actual or imminent problem, wherein such determination is accomplished without analysis of the input data or setpoint that was entered for such component; and

reporting the actual or imminent problem or sending an alert regarding the actual or imminent problem when it is determined that there is an actual or imminent problem.

13. An apparatus as recited in claim 12, wherein the component is a valve of the process system, the feedback specifies the delay for transitioning between an open and closed state and it is determined that there is an actual or imminent problem when such delay is greater than a predetermined duration.

14. An apparatus as recited in claim 12, wherein the component is a mass flow controller (MFC) or a unit pressure controller (UPC) of the process system, the feedback specifies the delay for transitioning between an idle and stable state and it is determined that there is an actual or imminent problem when such delay is greater than a predetermined duration.

15. An apparatus as recited in claim 12, wherein the component is a radio frequency (RF) generator of the process system, the feedback specifies the delay for transitioning between an on and off state and it is determined that there is an actual or imminent problem when such delay is greater than a predetermined duration.

16. An apparatus as recited in claim 12, wherein the component is an RF generator of the process system, the feedback specifies the delay for transitioning between an on and off state and it is determined that there is an actual or imminent problem when a rate of change of such delay over time is greater than a predetermined amount.

17. An apparatus as recited in claim 12, wherein the delay is a delay in a change in state of an RF power level or DC power level output and the determination is based on such output without being based on a RF or DC power level input to the component.

18. An apparatus as recited in claim 12, wherein the delay is a delay in a change in state of a flow level output and the determination is based on such output without being based on a flow level setpoint input to the component.

19. An apparatus as recited in claim 12, wherein the delay is a delay in a change in state of a rotational speed.

20. An apparatus as recited in claim 12, wherein the delay is a delay in a change in state of a specifies a voltage output.

21. An apparatus as recited in claim 12, wherein an alert regarding the actual or imminent problem is sent when it is determined that there is an actual or imminent problem, wherein at least one of the processors and memory are further operable for performing the following operations:

after an alert is sent, scheduling shutdown of the process system and re-routing wafers to another process system; and

examining the process system to determine a cause of the problem.

22. An apparatus as recited in claim 12, wherein determining whether there is an actual or imminent problem is accomplished by correlating the feedback with feedback from one or more components other to thereby predict failure is likely to occur under a set of conditions of the current and one or more other components.

25. An apparatus as recited in claim 12, wherein the feedback specifies a delay in a change in state of a characteristic of a component of the process system after entering of input data to cause the change in state of the component so as to result in a setpoint value for the component and output of the setpoint value is disabled so that the setpoint value remains as part of a recipe within the process system.

27. An apparatus as recited in claim 12, wherein at least one of the processors and memory are further operable for comparing the delay in the feedback to an expected delay in a change in state of the characteristic of the component of the process system after entering of input data or the setpoint and during the fabrication operation, wherein it is determined whether there is an actual or imminent problem when the comparison results in a significant difference.

23. A computer program product for monitoring a process system for performing a fabrication operation on a semiconductor wafer, the computer program product comprising:

at least one computer readable medium;

computer program instructions stored within the at least one computer readable product operable to cause a processing device to;

receive at a monitoring system feedback specifying a delay in a change in state of a characteristic of a component of the process system after entering of input data or a setpoint to cause the change in state of the component, wherein the specified delay occurs during a fabrication operation on the semiconductor wafer;

determine at the monitoring system whether there is an actual or imminent problem with operation of the component based on a timing analysis of the feedback from such component so as to determine whether there is a timing trend in the delay for the change in state that indicates an actual or imminent problem, wherein such determination is accomplished without analysis of the input data or setpoint that was entered for such component; and

report the actual or imminent problem or send an alert regarding the actual or imminent problem when it is determined that there is an actual or imminent problem.