Sensor geometry correction methods and apparatus

• US 6,741,945 B2
• Filed: 04/19/2002
• Issued: 05/25/2004
• Est. Priority Date: 04/19/2001
• Status: Expired due to Fees

• Current Assignee: KLA-Tencor Corporation
• Original Assignee: OnWafer Technologies, Inc. (KLA Corporation)
• Inventors: Spanos, Costas J., Polla, Kameshwar
• Primary Examiner(s): Bui, Bryan
• Application Number:
  US10/126,456
• Publication Number:
  US 20020177916A1
• Time in Patent Office: 767 Days
• Field of Search: 702/85, 702/90, 702/91, 702/99, 702/104, 702/130, 702/135, 700/108, 700/109, 700/110, 700/117, 700/121, 438/14, 438/17
• US Class Current: 702/104
• CPC Class Codes: G01D 3/022 having an ideal characteristic, map or correction data stored in a digital memory
• CPC Class Codes: H01L 21/67248 Temperature monitoring

Abstract

Described are methods and apparatus for collecting measured parameter data for applications such as deriving response models and information required for developing and maintaining processes and process tools. The methods and apparatus are capable of deriving correction factors for the measured data and applying the corrections factors to the measure data so as to provide corrected parameter data having increased accuracy. One embodiment uses warpage geometry to derive the correction factors.

Claims

1. A method of deriving operating characteristics for a process tool used for processing workpieces the method being performed with a sensor apparatus having a plurality of detectors, the method comprising the steps of:

a) loading a sensor apparatus including electronic devices into the process tool;

b) measuring the operating characteristics with the sensor apparatus;

c) converting the measured operating characteristics into digital data;

d) deriving correction factors for warpage induced measurement distortion; and

e) applying the correction factors to the measured data so as to generate corrected data.

2. A method according to claim 1 further comprising at least one step of:

i. storing the digital data in the sensor apparatus,

ii. transmitting the digital data to a receiver, and

iii. storing the digital data in the sensor apparatus and transmitting the digital data to a receiver.

3. A method of deriving operating characteristics for a process tool used for processing workpieces the method being performed with a sensor apparatus having a plurality of detectors, the method comprising the steps of:

a) loading a sensor apparatus including electronic devices into the process tool;

b) measuring the operating characteristics with the sensor apparatus;

c) converting the measured operating characteristics into digital data;

d) deriving correction factors for warpage induced measurement distortion; and

e) applying the correction factors to the measured data so as to generate corrected data;

wherein step d comprises solving analytically generated equations representing the behavior of at least a portion of the sensor apparatus.

4. A method according to claim 3 wherein the sensor apparatus solves the equations.

5. A method of deriving operating characteristics for a process tool used for processing workpieces the method being performed with a sensor apparatus having a plurality of detectors, the method comprising the steps of:

a) loading a sensor apparatus including electronic devices into the process tool;

b) measuring the operating characteristics with the sensor apparatus;

c) converting the measured operating characteristics into digital data;

d) deriving correction factors for warpage induced measurement distortion; and

e) applying the correction factors to the measured data so as to generate corrected data;

wherein step d comprises solving analytically generated equations representing the warpage of at least a portion of the sensor apparatus.

6. A method according to claim 5 wherein the operating characteristics are temperatures.

7. A method according to claim 5 wherein the operating characteristics are selected from the group consisting of plasma potential, etch rate, deposition rate, ion density, resistivity, and thermal flux.

8. A method according to claim 5 further comprising the step of transmitting the measured operating characteristics to an external information processor for deriving the correction factors and applying the correction factors to the measured operating characteristics.

9. An apparatus for acquiring measured parameter data and generating corrected data from the measured parameter data for processing workpieces, the apparatus comprising:

a base;

at least one base sensor supported by the base, the sensor being capable of measuring data representing a condition of the base;

an electronics module supported by the base;

an information processor substantially contained in the electronics module, the information processor being connected with the at least one base sensor so as to receive data from the at least one base sensor, the information processor being capable of deriving and applying correction factors from solving analytically generated equations representing the warpage of at least a portion of the sensor apparatus.

10. An apparatus according to claim 9 wherein the electronics module further comprises a transmitter for transmitting data.

11. An apparatus according to claim 9 wherein the electronics module further comprises a transmitter for wirelessly transmitting data.

12. An apparatus according to claim 9 wherein the base sensor comprises a temperature sensor.

13. An apparatus according to claim 9 wherein the base sensor comprises at least one of resistor temperature dependent sensors, thermistors, defined area probe for measuring plasma potential, defined area probe for measuring ion flux, Van der Paw cross for measuring etch rate, isolated field transistors for measuring plasma potential, current loops for measuring ion flux, and current loops for measuring radio frequency field.

14. An apparatus according to claim 9 wherein the information processor is capable of calculating correction factors for measurement distortion caused by warpage of the apparatus.

15. An apparatus according to claim 9 wherein the electronics module further comprises a transmitter for transmitting the corrected data.

16. An apparatus according to claim 9 wherein the electronics module further comprises a transmitter for wirelessly transmitting the corrected data.

17. An apparatus according to claim 9 wherein the electronics module is capable of at least one of

a) storing the corrected data, and

b) storing the corrected data and transmitting the corrected data.

18. An apparatus according to claim 9 wherein the base sensor comprises a temperature sensor.

19. An apparatus according to claim 9 wherein the base sensor comprises at least one of resistor temperature dependent sensors, thermistors, defined area probe for measuring plasma potential, defined area probe for measuring ion flux, Van der Paw cross for measuring etch rate, isolated field transistors for measuring plasma potential, current loops for measuring ion flux, and current loops for measuring radio frequency field.

20. A method of deriving parameter data for a uniform workpiece using measurements from a sensor apparatus, the sensor apparatus having at least one detector for measuring the parameter data, the sensor apparatus and workpiece having dissimilar warpage properties, the method comprising the steps of:

a) measuring the parameter data using the at least one detector;

b) providing at least one equation for substantially representing the warpage behavior of the sensor apparatus as a function of the parameter;

c) using the equation to derive correction factors; and

d) applying the correction factors to the parameter data so as to obtain corrected parameter data.

21. An apparatus for generating corrected temperature data for processing substrates in a process tool, the apparatus comprising:

a base;

at least one base temperature sensor coupled to the base, the at least one base temperature sensor being capable of measuring the temperature of the base;

an electronics module supported by the base, the electronics module having an information processor;

the information processor being connected with the at least one base temperature sensor so as to receive temperature data from the at least one base temperature sensor, the information processor being capable of calculating correction factors using a warpage geometry for at least a portion of the sensor apparatus;

the information processor being capable of applying the correction factors to the measured temperatures from the at least one base temperature sensor so as to obtain corrected temperature data.

22. An apparatus according to claim 21 wherein the base comprises a semiconductor wafer.

23. An apparatus according to claim 21 wherein the base comprises a flat panel display substrate.

24. A computer program product for correcting temperatures measured with a sensor apparatus, the sensor apparatus comprising a semiconductor wafer, and a plurality of temperature sensors coupled to the wafer, the computer program product comprising executable steps for:

a) acquiring measured wafer temperature data as a function of time and spatial position;

b) generating additional data by interpolation using the measured wafer temperature data so as to obtain temperatures for least one of a fine time scale and a fine spatial grid scale;

c) calculating temperature correction factors using a warpage geometry for at least a portion of the sensor apparatus;

d) reducing the correction factors of step c to at least one of the time scale of the measured temperatures and the spatial grid scale of the measured temperatures so as to correspond to step b; and

e) applying the correction factors to the measured wafer temperature data so as to provide corrected temperatures.

25. A system for collecting and correcting parameter measurements, the system comprising a sensor apparatus for collecting measurement data, an external information processor, and a communication mechanism for transmitting information between the sensor apparatus and the external information processor, the external information processor being capable of generating correction factors using a warpage geometry for at least a portion of the sensor apparatus for correcting the parameter measurements and applying the correction factors to the measurement data so as to obtain corrected measurement data.

26. A system according to claim 25 wherein the communication mechanism is capable of wireless information transfer.

27. A system according to claim 25 wherein the communication mechanism is capable of wireless information transfer using the infrared spectrum.

28. A system according to claim 25 wherein the external information processor comprises at least one of a microprocessor, a central processing unit, and a computer.

29. A computer program product for correcting temperatures measured with a sensor apparatus, the sensor apparatus comprising a semiconductor wafer, and a plurality of temperature sensors coupled to the wafer, the computer program product comprising executable steps for:

a) acquiring measured wafer temperature data as a function of time and spatial position;

b) calculating temperature correction factors using a warpage geometry for at least a portion of the sensor apparatus and solving analytically generated equations representing the behavior of at least a portion of the sensor apparatus; and

c) applying the correction factors to the measured wafer temperature data so as to provide corrected temperatures.