Apparatus and method for detection and measurement of environmental parameters

• US 6,693,432 B2
• Filed: 10/22/2002
• Issued: 02/17/2004
• Est. Priority Date: 06/06/2001
• Status: Active Grant

• Current Assignee: Desco Industries Incorporated
• Original Assignee: Credence Technologies, Inc. (3M Company)
• Inventors: Kraz, Vladimir
• Primary Examiner(s): Snow, Walter E.
• Assistant Examiner(s): KERVEROS, JAMES C
• Application Number:
  US10/278,564
• Publication Number:
  US 20030052691A1
• Time in Patent Office: 483 Days
• Field of Search: 324/457, 324/458, 324/72, 324/72.5, 324/452, 343/701, 343/703, 375/219, 375/220, 438/275
• US Class Current: 324/457
• CPC Class Codes: G01R 29/12 Measuring electrostatic fields or voltage-potential
• CPC Class Codes: G03F 1/44 Testing or measuring features, e.g. grid patterns, focus monitors, sawtooth scales or notched scales
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring

Abstract

The present invention provides a device for in-situ measurement and recording of various environmental parameters in a semiconductor fabrication process. The device includes sensors for detecting the parameters and converting them to sensor outputs and a data logger coupled to the sensors for receiving the sensor outputs and logging them in a file. The device may also include an analog to digital converter to convert the sensor outputs to digital data and a communication module to communicate the digital data with other devices. When applied to reticles used in a semiconductor fabrication process comprising a plurality of stages, the device may be used to monitor electrostatic field and electrostatic discharge activities on and around the reticle, convert the monitored parameters into data, and log the data along with a timestamp and an identification of each individual stage. Logged data can be retrieved and analyzed to determine the time and location of detrimental activities such as electrostatic discharge on reticles.

Claims

1. A method for in-situ measurement and recording of at least one parameter in a semiconductor fabrication process comprising a plurality of stages, said method comprising:

(a) monitoring said parameter in a stage of said plurality of stages, said parameter including at least one of a magnitude and a rate of change;

(b) converting said parameter into data;

(c) logging said data and an identification of said stage into a data logger that moves through the plurality of stages during the fabrication process; and

(d) repeating (a)-(d) for said plurality of stages.

2. The method of claim 1 further comprising timestamping said data.

3. The method of claim 2 further comprising signal processing said data.

4. The method of claim 3 further comprising converting said data into digital data.

5. The method of claim 4 further comprising communicating said digital data and said identification of said stage to a base equipment.

6. The method of claim 5 wherein said parameter comprises electrostatic field.

7. The method of claim 6 wherein said parameter comprises a change in said electrostatic field.

8. The method of claim 7 wherein said parameter comprises an electrostatic discharge.

9. The method of claim 8 further comprising eliminating extraneous electrostatic discharges based on said electrostatic discharge and said electrostatic field.

10. A device for in-situ monitoring of at least one environmental parameter in a photolithographic process comprising a plurality of stages, said device comprising:

at least one sensor for converting said environmental parameter of an associated stage into a sensor output;

an analog to digital converter for converting said sensor output to digital data;

a data logger that receives and stores said sensor output while moving through the plurality of stages; and

a communication module to communicate said digital data and an identification of said associated stage of said plurality of stages.

11. The device of claim 10 further comprising a data logger for logging said digital data and said identification of said associated stage.

12. The device of claim 11 wherein said communication module comprises a transmitter and a receiver.

13. The device of claim 11 wherein said communication module comprises an RF (radio frequency) communication module.

14. The device of claim 10 further comprising a display device.

15. The device of claim 10 further comprising a sensor for detecting a presence of electrostatic field.

16. The device of claim 15 wherein said sensor is configured to measure a magnitude of said electrostatic field.

17. The device of claim 16 wherein said sensor is configured to detect a change in said electrostatic field.

18. The device of claim 10 further comprising a sensor for detecting an electrostatic discharge.

19. The device of claim 18 wherein said sensor is configured to measure a magnitude of said electrostatic discharge.

20. The device of claim 10 further comprising signal processing circuitry coupled to said at least one sensor for processing said sensor output.

21. A device for use in conjunction with a reticle for in-situ monitoring of at least one electrical parameter in a semiconductor fabrication process comprising a plurality of stages, said device comprising:

a sensor for converting said electrical parameter of a stage into a sensor output;

an analog to digital converter for converting said sensor output to digital data;

a data logger comprising a timestamping module for logging said digital data and an identification of said stage, wherein the data logger is attached to said sensor and moves through the plurality of stages; and

an RF (radio frequency) communication module coupled to said data logger.

22. The device of claim 21 wherein said electrical parameter comprises electrostatic field.

23. The device of claim 21 wherein electrical parameter comprises an electrostatic discharge.

26. The method of claim 23 further comprising:

signal processing said data.

27. The method of claim 26 further comprising:

converting said data into digital data.

28. The method of claim 26 further comprising:

communicating said digital data and said identification of said stage to a base equipment.

29. The method of claim 28 wherein said parameter comprises electrostatic field.

30. The method of claim 28 wherein said parameter comprises an electrostatic discharge.

24. A method for in-situ measurement and recording of at least one parameter in a semiconductor fabrication process comprising at least one stage, said method comprising:

(a) monitoring said parameter in said stage, wherein said parameter includes at least one of a magnitude and a rate of change;

(b) converting said parameter into data; and

(c) logging said data and an identification of said stage into a data logger that moves through said at least one stage of the process.

25. The method of claim 24 further comprising timestamping said data.