Lithographic Apparatus, Device Manufacturing Method and Device

• US 20080165332A1
• Filed: 11/30/2007
• Published: 07/10/2008
• Est. Priority Date: 12/01/2006
• Status: Active Grant

• Current Assignee: ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Netherlands BV (ASML Holding NV)
• Inventors: Van Der Schaar, Maurits, Mos, Everhardus Cornelis, Simons, Hubertus Johannes Gertrudus
• Granted Patent: US 8,248,579 B2
• Time in Patent Office: Days
• US Class Current: 355/52
• CPC Class Codes: G03F 7/70258 Projection system adjustments, e.g. adjustments during exposure or alignment during assembly of projection system
• CPC Class Codes: G03F 7/70358 Scanning exposure, i.e. relative movement of patterned beam and workpiece during imaging
• CPC Class Codes: G03F 7/70458 Mix-and-match, i.e. multiple exposures of the same area using a similar type of exposure apparatus, e.g. multiple exposures using a UV apparatus
• CPC Class Codes: G03F 7/70525 Controlling normal operating mode, e.g. matching different apparatus, remote control or prediction of failure
• CPC Class Codes: G03F 7/70633 Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching
• CPC Class Codes: G03F 7/70725 control
• CPC Class Codes: G03F 7/70783 Handling stress or warp of chucks, masks or workpieces, e.g. to compensate for imaging errors or considerations related to warpage of masks or workpieces due to their own weight

Abstract

A lithographic apparatus includes an illumination system configured to condition a radiation beam, a support for a patterning device, a substrate table for a substrate, a projection system, and a control system. The patterning device is capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam. The projection system is configured to project the patterned radiation beam as an image onto a target portion of the substrate along a scan path. The scan path is defined by a trajectory in a scanning direction of an exposure field of the lithographic apparatus. The control system is coupled to the support, the substrate table and the projection system for controlling an action of the support, the substrate table and the projection system, respectively. The control system is configured to correct a local distortion of the image in a region along the scan path by a temporal adjustment of the image in that region.

Claims

1. A method of imaging overlapping patterns on a target field of a substrate, comprising:

providing overlay errors between the overlapping patterns, the provided overlay errors corresponding to controlling the process according to a suggested value for each of at least one process parameters of a model of the process;

determining a value for each of the at least one process parameters corresponding to minimal overlay errors by fitting the model to data comprising the provided overlay errors and the suggested values for each of the at least one process parameters;

creating the overlapping patterns thereby controlling the process according to the determined values for each of the at least one the process parameters; and

creating a first part of one of the overlapping patterns according to a first determined value for each of the at least one process parameters and creating a second part of the one of the overlapping patterns according to a second determined value for each of the at least one the process parameters wherein the first value differs from the second value.

2. A method according to claim 1, wherein the overlapping patterns comprise a first pattern and a second pattern and wherein the one of the overlapping patterns is the first pattern.

3. A method according to claim 2, wherein providing the overlay errors comprises estimating the overlay errors based on data on the creation of only one of the overlapping patterns.

4. A method according to claim 3, wherein the only one of the overlapping patterns is the second pattern.

5. A method according to claim 2, wherein providing the overlay errors comprises measuring overlay errors on a test substrate processed according to the suggested values for each of the at least one process parameters.

6. A method according to claim 2, wherein the second pattern is created on the substrate earlier than the first pattern.

7. A method according to claim 1, wherein the process is a lithographic process.

8. A method according to claim 7, further comprising:

patterning a radiation beam using a patterning device, and

creating the first part and the second part of the one of the overlapping patterns by illuminating the target field by the patterned radiation beam.

9. A method according to claim 8, further comprising:

estimating the overlay errors using measurements of features of the patterning device.

10. A method according to claim 8, further comprising:

scanning the patterning device with respect to a projection system;

creating a first image of a first section of the patterning device at a first moment in time, the image being created in a slit;

creating a second image of a second section of the patterning device at a second moment in time, the image being created in a slit and whereby the second moment differs from the first moment and whereby the first section of the patterning device differs from the second section of the patterning device; and

scanning the target field with respect to the slit thereby illuminating the first section of the target field with the first image and illuminating the second section of the target field with the second image;

whereby the first image and the second image are shrunk with respect to the first section and the second section respectively of the patterning device with an image demagnification factor.

11. A method according to claim 10, wherein at least one of the process parameters comprises an image demagnification factor.

12. A method according to claim 10, wherein at least one of the process parameters comprises information corresponding to a third order aberration of the projection system.

13. A method according to claim 10, wherein the patterning device is scanned with respect to the projection system and wherein the target field and the slit are scanned with respect to each other according to at least one scan parameter comprising trajectory and velocity and wherein at least one of the each of at least one process parameters corresponds to one of the at least one scan parameters.

14. A method according to claim 13, wherein at least one of the scan parameters comprises information corresponding to a velocity of the target field with respect to the slit or corresponds to a velocity of the patterning device with respect to the projection system.

15. A method according to claim 13, wherein the patterning device is scanned with respect to the projection system in a first direction and the target field is scanned with respect to the slit in a second direction;

wherein at least one of the scan parameters corresponds to a component of the second direction, the component being perpendicular to the first direction.

16. A method according to claim 13, wherein one of the scan parameters corresponds to the rotation of the patterning device with respect to the target field.

17. An apparatus arranged to determine a value of a process parameter of a process for creating overlapping patterns on a substrate comprising:

a processor configured and arranged to fit a model of the process to data comprising a suggested value of the process parameter and estimated overlay errors between the overlapping patterns,

wherein the estimated overlay errors correspond to control of the process according to the suggested value of the process parameter, whereby the determined value of the process parameter corresponds to minimal overlay errors;

the processor further being configured and arranged to determine a first value of the process parameter for creating a first part of one of the overlapping patterns in a first section of the target field and a second value of the process parameter for creating a second part of the one of the overlapping patterns, wherein the first value differs from the second value.

18. An apparatus according to claim 17, wherein the processor is further arranged to estimate the overlay errors using measurements of overlay errors on a test substrate processed according to the suggested value of the process parameter.

19. An apparatus according to claim 18, wherein the apparatus further comprises metrology devices configured arranged to perform the measurements of the overlay errors.

20. An apparatus according to claim 17, for use in a process comprising patterning a radiation beam with a patterning device and creating a first part and the second part of the one of the overlapping patterns on the target field using the patterned radiation beam, wherein the processor is further configured and arranged to estimate the overlay errors using measurements of features of a patterning device.

21. An apparatus according to claim 17 for use in a process comprising patterning a radiation beam with a patterning device and creating a first part and the second part of the one of the overlapping patterns on the target field using the patterned radiation beam, wherein the processor is further arranged to estimate the overlay errors using information on the creation of the patterning device.

22. An apparatus for creating a first pattern of several overlapping patterns on a substrate comprising a substrate table to hold the substrate, and comprising:

a patterning module constructed and arranged to create a first part of a first pattern in a first section of a target field and to create a second part of the first pattern in a second section of the target field, wherein the first part differs from the second part and the first section differs from the second section;

a controller connected to the patterning module and the substrate table and arranged to control the overlay between the first pattern and a second pattern of the several overlapping patterns by controlling the substrate table and the patterning module based on values of a group of process parameters; and

wherein the apparatus is configured and arranged to create the first part according to a first value of a first process parameter of the group of process parameters and to create the second part according to a second value of the first process parameter.

23. An apparatus according to claim 22, wherein the patterning module comprises a projection system arranged to image a patterning device supported by the apparatus wherein the image is smaller than the patterning device by an image demagnification factor, the patterning module further comprising a projection system control, constructed and arranged to control the demagnification factor based on the first and second value of the first process parameter.