Lithographic attribute enhancement

• US 7,738,075 B2
• Filed: 05/23/2005
• Issued: 06/15/2010
• Est. Priority Date: 05/23/2005
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Davis, Todd J., Owen, Cassandra M., Hiar, Todd D., Paxton, Theodore A.
• Primary Examiner(s): Kim; Peter B
• Application Number:
  US11/134,625
• Publication Number:
  US 20060262287A1
• Time in Patent Office: 1,849 Days
• Field of Search: 355/30, 355/53, 355/72, 355/77, 355/75, 702/136, 430/30
• US Class Current: 355/30
• CPC Class Codes: G03F 7/70616 Monitoring the printed patterns
• CPC Class Codes: G03F 7/70875 Temperature, e.g. temperature control of masks or workpieces via control of stage temperature

Abstract

A method, computer program product, and apparatus configured to improve attribute uniformity of a substrate is disclosed. In an embodiment, the method involves calculating corrective data based on measured values of an attribute of a substrate processed by a lithographic exposure apparatus, the corrective data configured to at least partially correct non-uniformity of the values of the substrate attribute by controlling the temperature generated by a zone of a thermal plate used to heat or cool the substrate, and making the corrective data available to the thermal plate.

Claims

1. A method comprising:

characterizing a temperature response for one or more zones of a thermal plate based on an application of different temperature zone offsets to each of the one or more zones of the thermal plate during exposure of a first pattern on a surface of a substrate;

measuring a value of an attribute of a second pattern exposed on the surface of the substrate;

calculating corrective data based on the measured value of the attribute of the second pattern exposed on the surface of the substrate, the corrective data at least partially correcting non-uniformity of the value of the attribute of the second pattern exposed on the surface of the substrate; and

controlling temperature of the one or more zones of the thermal plate, wherein the thermal plate is used to heat or cool the substrate during the lithographic exposure process based on the corrective data.

2. The method of claim 1, wherein the attribute is a critical dimension of a feature on the exposed substrate.

3. The method of claim 1, wherein the attribute is at least one of a sidewall angle, a line edge roughness, a post diameter, a contact size, a line width, a space width, and an alignment position of a feature on the exposed substrate.

4. The method of claim 1, further comprising heating the substrate in accordance with the corrective data.

5. The method of claim 1, wherein the thermal plate comprises a post-exposure bake plate configured to heat the substrate after exposure of the substrate with the second pattern.

6. The method of claim 1, further comprising:

assessing whether the measured value of the attribute is sufficiently uniform based on substrate profile information; and

upon determining that the measured value of the attribute is not uniform, calculating the corrective data.

7. The method of claim 1, wherein the characterizing the temperature response comprises determining a zone offset response used in calculating the corrective data, the zone offset response comprising a measure of change of a substrate attribute value per unit of zone offset change.

8. The method of claim 1, further comprising updating a zone offset response, used in calculating the corrective data, based on the measured value of the attribute.

9. The method of claim 1, wherein the calculating the corrective data comprises using substrate processing and configuration information, the substrate processing and configuration information including at least one of data associated with a processing path of the substrate through one or more processing apparatus, pre-exposure measurement data, and exposure requirements and parameters.

10. The method of claim 1, further comprising controlling one or more lithographic processing apparatus used after the heating or cooling by the thermal plate in a lithographic exposure process based on the corrective data.

11. The method of claim 1, wherein the characterizing the temperature response comprises:

exposing the first pattern on the surface of the substrate, wherein the first pattern has a known process history;

measuring an attribute associated with the first pattern;

correlating the attribute associated with the first pattern to a change in a corresponding zone offset; and

calculating a change in the attribute associated with the first pattern per unit zone offset change.

12. A computer readable program product, embodied in a tangible medium, encoded with instructions that, if executed by a computing device causes the computing device to perform a method comprising:

characterizing a temperature response for one or more zones of a thermal plate based on an application of different temperature zone offsets to each of the one or more zones of the thermal plate during exposure of a first pattern on a surface of a substrate;

calculating corrective data based on a value of an attribute of a second pattern exposed on the surface of the substrate the corrective data at least partially correcting non-uniformity of the value of the attribute of the second pattern exposed on the surface of the substrate; and

controlling temperature of the one or more zones of the thermal plate, wherein the thermal plate is used to heat or cool the substrate based on the corrective data.

13. The computer program product of claim 12, wherein the attribute is a critical dimension of a feature on the exposed substrate.

14. The computer program product of claim 12, wherein the attribute is at least one of a sidewall angle, a line edge roughness, a post diameter, a contact size, a line width, a space width, and an alignment position of a feature on the exposed substrate.

15. The computer program product of claim 12, wherein the thermal plate comprises a post-exposure bake plate configured to heat the substrate after exposure of the substrate with the second pattern.

16. The computer program product of claim 12, wherein the method further comprises:

measuring the value of the attribute of the second pattern exposed on the surface of the substrate;

assessing whether the measured value of the attribute is sufficiently uniform based on substrate profile information; and

upon determining that the measured value of the attribute is not uniform, calculating the corrective data.

17. The computer program product of claim 12, wherein the characterizing the temperature response comprises determining a zone offset response used in calculating the corrective data, the zone offset response comprising a measure of change of an attribute value per unit of zone offset change.

18. The computer program product of claim 12, wherein the method further comprises updating a zone offset response, used in calculating the corrective data, based on the measured values of the attribute.

19. The computer program product of claim 12, wherein the calculating the corrective data comprises using substrate processing and configuration information, the substrate processing and configuration information including at least one of data associated with a processing path of the substrate through one or more processing apparatus, pre-exposure measurement data, and exposure requirements and parameters.

20. The computer readable program product of claim 12, wherein the method further comprises controlling one or more lithographic processing apparatus used after the heating or cooling by the thermal plate in a lithographic exposure process based on the corrective data.

21. A thermal plate system, comprising:

a thermal plate configured to heat or cool a substrate and comprising a plurality of zones; and

a controller configured to;

characterize a temperature response for a plurality of zones of a thermal plate based on an application of different temperature zone offsets to each of the plurality of zones of the thermal plate during exposure of a first pattern on a surface of a substrate; and

calculate corrective data based on a measured value of an attribute of a second pattern exposed on the surface of the substrate and to control temperature generated by a zone of the plurality of zones based on the corrective data, the corrective data configured to at least partially correct non-uniformity of the value of the attribute of the second pattern exposed on the surface of the substrate.

22. The thermal plate system of claim 21, wherein the thermal plate comprises a post-exposure bake plate configured to heat the substrate after exposure of the substrate with the second pattern by the lithographic exposure apparatus.

23. The thermal plate system of claim 21, wherein the attribute is a critical dimension of a feature on the exposed substrate.

24. The thermal plate system of claim 21, wherein the attribute is at least one of a sidewall angle, a line edge roughness, a post diameter, a contact size, a line width, a space width, and an alignment position of a feature on the exposed substrate.

25. The thermal plate system of claim 21, wherein the controller is configured to control one or more lithographic processing apparatus used after the heating or cooling by the thermal plate in the lithographic exposure process based on the corrective data.

26. A lithographic apparatus, comprising:

a projection system configured to project a patterned beam of radiation onto a substrate;

a substrate holder configured to hold the substrate;

a thermal plate configured to heat or cool a substrate and comprising a plurality of zones; and

a controller configured to;

characterize a temperature response for the plurality of zones of the thermal plate based on an application of different temperature zone offsets to each of the plurality of zones of the thermal plate during exposure of a first pattern on a surface of the substrate; and

calculate corrective data based on a sensor measured value of an attribute of a second pattern exposed on the surface of the substrate, to control temperature generated by a zone of the plurality of zones based on the corrective data, the corrective data configured to at least partially correct non-uniformity of the value of the attribute of the second pattern exposed on the surface of the substrate.

27. The apparatus of claim 26, further comprising a measuring device configured to measure the attribute of the substrate.

28. The apparatus of claim 26, wherein the attribute is at least one of a critical dimension, a sidewall angle, a line edge roughness, a post diameter, a contact size, a line width, a space width, and an alignment position of a feature on the exposed substrate.

29. The lithographic apparatus of claim 26, wherein the controller is configured to control one or more lithographic processing apparatus used after the heating or cooling by the thermal plate in the lithographic exposure process based on the corrective data.