Data collection and correction methods and apparatus

• US 6,738,722 B2
• Filed: 04/19/2002
• Issued: 05/18/2004
• Est. Priority Date: 04/19/2001
• Status: Expired due to Term

• 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:
  US10/126,457
• Publication Number:
  US 20020177917A1
• Time in Patent Office: 760 Days
• Field of Search: 702/85, 702/90, 702/91, 702/99, 702/104, 702/130, 702/135, 700/108-109, 700/110, 700/117, 700/121, 438/14, 438/17, 324/750, 324/755, 324/763-765
• 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 measured data so as to provide corrected parameter data having increased accuracy.

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 the measurements; 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 the measurements; 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 step d includes using the equations and measurements from at least one of the sensors so as to derive the correction factors.

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

6. A method according to claim 3 wherein the operating characteristics are temperatures.

7. A method according to claim 3 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 3 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 generating corrected data for process tools used 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 comprising an information processor, the electronics module being supported by the base;

at least one electronics module sensor coupled to the electronics module for measuring data representing a condition of the electronics module; and

the information processor being connected with the base sensor and the electronics module sensor so as to receive data from the sensors.

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 and the electronics module sensor comprises a temperature sensor.

13. An apparatus according to claim 9 wherein the base sensor and the electronics module 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 using at least one characteristic of the electronics module and data from the information processor sensor;

the information processor being capable of applying the correction factors to the measured parameters from the base sensor so as to obtain corrected data for the parameters.

15. An apparatus according to claim 14 wherein the electronics module further comprises a transmitter for transmitting the corrected data.

16. An apparatus according to claim 14 wherein the electronics module further comprises a transmitter for wirelessly transmitting the corrected data.

17. An apparatus according to claim 14 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 14 wherein the base sensor comprises a temperature sensor and the electronics module sensor comprises a temperature sensor.

19. An apparatus according to claim 14 wherein the base sensor and the electronics module 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. An method of deriving corrected parameter data for a uniform workpiece using parameter measurements from a sensor apparatus having a first portion and a second portion, the first portion and the second portion having dissimilar properties, the workpiece and the first portion having substantially similar properties, the method comprising the step of:

a) coupling at least one detector with the first portion of the sensor apparatus, the first portion having substantially uniform properties;

b) coupling at least one detector with the second portion of the sensor apparatus, the second portion having substantially uniform properties;

c) measuring the parameter using the at least one detector of step a;

d) measuring the parameter using the at least one detector of step b;

e) providing at least one property of the second portion of the sensor apparatus;

f) providing at least one equation for substantially representing the behavior of the second portion as a function of the parameter;

g) using the equation and parameter measurements for the second portion to derive correction factors; and

h) applying the correction factors to the measured parameters so as to obtain the corrected parameter data.

21. A method of deriving corrected parameter data for a substantially uniform workpiece using parameter measurements from a sensor apparatus, the workpiece and at least a portion of the sensor apparatus having dissimilar properties, the method comprising the steps of:

a) coupling at least one detector with a first portion of the sensor apparatus, the first portion having substantially uniform properties, the first portion having properties substantially similar to the properties of the workpiece;

b) coupling at least one detector with a second portion of the sensor apparatus, the second portion having substantially uniform properties, wherein the properties of the workpiece and the properties of the second portion are dissimilar;

c) measuring the parameter using the at least one detector of step a;

d) measuring the parameter using the at least one detector of step b;

e) providing at least one property of the second portion of the sensor apparatus;

f) providing at least one equation for substantially representing the behavior of the second portion as a function of the parameter;

g) using the equation of step f and parameter measurements for the second portion to derive correction factor; and

h) applying the correction factors to the measured parameters so as to obtain the corrected parameter data.

22. 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;

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

the information processor being connected with the base temperature sensor and the electronics module temperature sensor so as to receive temperature data from the at least one base temperature sensor and the at least one electronics module sensor, the information processor being capable of calculating correction factors using at least one thermal conductivity characteristic of the information processor and the temperature data from the information processor temperature sensor;

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.

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

24. An apparatus according to claim 22 wherein the base comprises a flat panel display substrate.

25. A computer program product for correcting temperatures measured with a sensor apparatus, the sensor apparatus comprising a semiconductor wafer, a plurality of temperature sensors coupled to the wafer, an electronics module supported by the wafer, and a temperature sensor coupled to the electronics module, 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) acquiring measured electronics module temperature data;

d) calculating temperature correction factors using heat transfer coefficients for the electronics module and the measured electronics module temperature data;

e) reducing the correction factors of step d 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

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

26. A system for collecting and correcting parameter measurements, the system comprising a sensor apparatus for collecting parameter measurements for correction and collecting parameter measurements for generating correction factors, the sensor apparatus comprising a base, at least one base sensor supported by the base, an electronics module comprising an information processor, the electronics module being supported by the base, at least one electronics module sensor coupled to the electronics module for measuring data representing a condition of the electronics module, the information processor being connected with the base sensor and the electronics module sensor so as to receive 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 the parameter measurements for generating correction factors for correcting the parameter measurements and applying the correction factors to the parameter measurements for correction so as to obtain corrected parameter measurements data.

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

28. A system according to claim 26 wherein the communication mechanism is capable of wireless information transfer using the infrared spectrum.

29. A system according to claim 26 wherein the external information processor comprises at least one of a microprocessor, a central processing unit, and a computer.