METHOD AND SYSTEM FOR MONITORING PHOTOLITHOGRAPHY PROCESSING BASED ON A BATCH CHANGE IN LIGHT SENSITIVE MATERIAL

• US 20080204734A1
• Filed: 02/23/2007
• Published: 08/28/2008
• Est. Priority Date: 02/23/2007
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Dixon, David, Swain, Bryan
• Granted Patent: US 7,591,600 B2
• Time in Patent Office: Days
• US Class Current: 356/237.3
• CPC Class Codes: G03F 7/70425 Imaging strategies, e.g. for increasing throughput or resolution, printing product fields larger than the image field or compensating lithography- or non-lithography errors, e.g. proximity correction, mix-and-match, stitching or double patterning
• CPC Class Codes: G03F 7/70608 Monitoring the unpatterned workpiece, e.g. measuring thickness, reflectivity or effects of immersion liquid on resist
• CPC Class Codes: G03F 7/70625 Dimensions, e.g. line width, critical dimension [CD], profile, sidewall angle or edge roughness

Abstract

A method for monitoring photolithography processing includes monitoring application of a light sensitive material to the surface of each of a plurality of substrates and detecting that a supply of the light sensitive material applied to the substrates has changed from a first batch of light sensitive material to a second batch light sensitive material. A change in photolithography process results caused by the change from the first batch to the second batch of light sensitive material is determined. Also included is initiating corrective action based on the change in photolithography process results.

Claims

1. A method for monitoring photolithography processing, comprising:

monitoring application of a light sensitive material to the surface of each of a plurality of substrates;

detecting that a supply of the light sensitive material applied to the substrates has changed from a first batch of light sensitive material to a second batch light sensitive material;

determining a change in photolithography process results caused by the change from the first batch to the second batch of light sensitive material; and

initiating corrective action based on the change in photolithography process results.

2. The method of claim 1, wherein said detecting comprises identifying a first substrate that the second batch of light sensitive material is applied to.

3. The method of claim 2, wherein said identifying comprises:

detecting when a system that supplies the light sensitive material changes from a first container containing the first batch of light sensitive material to a second container containing the second batch of light sensitive material;

determining when the first batch of light sensitive material is exhausted from a feed system and the second batch of light sensitive material begins to be dispensed from the feed system onto the substrates based on a feed rate of the light sensitive material and a volume of the feed system; and

identifying a substrate that will receive light sensitive material when the second batch of light sensitive material begins to be dispensed from the feed system as the first substrate.

4. The method of claim 2, wherein said identifying comprises:

monitoring a characteristic of the light sensitive material applied to the substrates;

detecting a change in said characteristic representing a change from the first batch of light sensitive material to the second batch of light sensitive material; and

identifying a substrate that will receive light sensitive material when said change in characteristic occurs as the first substrate.

5. The method of claim 4, wherein said characteristic comprises a viscosity of the light sensitive material.

6. The method of claim 4, wherein said characteristic comprises a concentration of a component of the light sensitive material.

7. The method of claim 2, wherein said identifying comprises:

detecting when a system that supplies the light sensitive material changes from a first container containing the first batch of light sensitive material to a second container containing the second batch of light sensitive material; and

after detecting said change to a second container, performing an optical metrology measurement on said substrates to identify said first substrate based on a change in optical metrology measurement results from wafer to wafer.

8. The method of claim 7, wherein said determining a change in photolithography process results caused by the change the first batch to the second batch of light sensitive material is performed based on said optical metrology measurement results.

9. The method of claim 1, wherein said detecting comprises detecting an age of the supply of the light sensitive material applied to the substrates, wherein a predetermined age causes the light sensitive material to change from said first batch of light sensitive material to said second batch light sensitive material.

10. The method of claim 1, wherein said determining comprises:

performing optical metrology measurements of a feature formed in the light sensitive material applied on the substrate;

detecting a change in a profile of the feature caused by the change in batch of light sensitive material.

11. The method of claim 10, wherein said performing comprises performing said optical metrology measurements on an in-line optical metrology system integrated into a photolithography system that is performing the photolithography process.

12. The method of claim 11, further comprising feeding forward batch change data resulting from said determining step to the in-line optical metrology system.

13. The method of claim 12 further comprising using said batch change data to modify a sampling plan in the optical metrology measurement system.

14. The method of claim 12, further comprising using said batch change data to select a predetermined optical metrology measurement recipe configured to detect said change in profile of the feature caused by the change in batch of light sensitive solution.

15. The method of claim 12, further comprising sending a batch change signal and results of said optical metrology measurement from the photolithography system to a fab host computer.

16. The method of claim 10, wherein said performing comprises performing said optical metrology measurements on an off-line optical metrology system that is not integrated into a photolithography system that is performing the photolithography process.

17. The method of claim 16, further comprising identifying a first substrate that the second batch of light sensitive material is applied to, wherein said performing comprises performing said optical metrology measurements on said first substrate.

18. The method of claim 16, wherein said performing comprises performing said optical metrology measurements at a predetermined measurement recipe configured to detect said change in profile of the feature caused by the change in batch of light sensitive solution.

19. The method of claim 2, wherein said determining comprises performing an predetermined inspection on at least the first substrate, said predetermined inspection being configured to detect a change in photolithography processing results based on a change in batch of light sensitive solution.

20. The method of claim 19, wherein said predetermined inspection comprises a scanning electron microscope (SEM) inspection of at least the first substrate.

21. The method of claim 19, wherein said predetermined inspection comprises a post etch inspection of at least the first substrate.

22. The method of claim 1, wherein said corrective action comprises changing a recipe of the photolithography processing to compensate for said change in photolithography process results caused by the change of the first batch to the second batch of light sensitive material.

23. The method of claim 22, wherein said changing a recipe comprises changing an exposure step or a developing step or both of these to compensate for said change in photolithography process results caused by the change the first batch to the second batch of light sensitive material.

24. The method of claim 1, wherein said corrective action comprises changing recipe of an etching process performed after said photolithography processing to compensate for said change in photolithography process results caused by the change the first batch to the second batch of light sensitive material.

25. A system for monitoring photolithography processing, comprising:

a coating device configured to apply light sensitive material to the surface of each of a plurality of substrates;

a detector configured to detect that a supply of the light sensitive material applied to the substrates has changed from a first batch of light sensitive material to a second batch light sensitive material;

an inspection device configured to determine a change in photolithography process results caused by the change from the first batch to the second batch of light sensitive material.

26. The system of claim 25, wherein said detector comprises a controller configured to:

detect when a system that supplies the light sensitive material changes from a first container containing the first batch of light sensitive material to a second container containing the second batch of light sensitive material;

determine when the first batch of light sensitive material is exhausted from a feed system and the second batch of light sensitive material begins to be dispensed from the feed system onto the substrates based on a feed rate of the light sensitive material and a volume of the feed system; and

identify a first substrate that will receive light sensitive material when the second batch of light sensitive material begins to be dispensed from the feed system.

27. The system of claim 26, wherein said detector comprises:

a sensor configured to monitor a characteristic of the light sensitive material applied to the substrates; and

a controller configured to detect a change in said characteristic representing a change from the first batch of light sensitive material to the second batch of light sensitive material and identify a first substrate that will receive light sensitive material when said change in characteristic occurs.

28. The system of claim 25, wherein said detector comprises an in-line optical metrology system or an off-line optical metrology system.

29. The system of claim 25, wherein said inspection device comprises an in-line optical metrology system or an off-line optical metrology system.

30. The system of claim 27, wherein said sensor comprises a viscosity measurement device.

31. The system of claim 27, wherein said sensor comprises a chemical species concentration detector.