NL2036125B1

NL2036125B1 - Positioning stage system for movement of an object relative to a process device.

Info

Publication number: NL2036125B1
Application number: NL2036125A
Authority: NL
Inventors: Mathijs Vogels Johannes; Patti Francesco; Jagannathrao Kalas Vinayak
Original assignee: Vdl Enabling Tech Group B V
Priority date: 2023-10-26
Filing date: 2023-10-26
Publication date: 2025-05-12

Abstract

A B S T R A C T According to a first example of the disclosure, a positioning stage system for precise and accurate movement of an object relative to a process device is proposed. In this example the positioning system comprises a stage unit for supporting the object; a drive unit for displacing the stage around at least a pivot point, as well as a vibration control unit structured to counteract external vibrations acting on the pivot point. This ensures an effective compensation for vibration induced displacements, thus improving sic. establishing a more precise and accurate movement of the object relative to the process device. Figure 2

Description

TITLE

Positioning stage system for movement of an object relative to a process device.

TECHNICAL FIELD

The present disclosure relates to positioning stage systems, in particular to positioning stage systems for use in the photolithography industry.

BACKGROUND OF THE DISCLOSURE

Metrology tool stages are known in e.g. the photolithography industry.

The displacement and positioning of an object, e.g. a wafer substrate relative to a process device require high accuracy and reproducibility, and accordingly high requirements are allotted to positioning stage systems for proper execution of such movements and handling of such objects (wafer substrates). The process device could be another type of stage e.g. a metrology stage or another positioning stage.

Drawbacks associated with known configuration of metrology tool stages are e.g. large tool footprints, limited stage acceleration due the presence of moving parts with a significant mass, and vibrations. In particular in photolithography applications where a much higher demand is given to accuracy and maximum control of the photolithography process steps, vibrations are detrimental for any positioning movement.

In particular, it is important that the position achieved of an object (wafer) body with respect to another body, here a metrology stage is affected as little as possible due to vibrations. Vibrations of the frame or housing of metrology tool stages will generate inertia forces which will produce displacements of the object (wafer). As it is desired to limit such distorted displacements, the control system of the metrology tool stage, which controls the displacement of the object will have to be able to follow the vibration induced displacements and compensate for them. In general, this leads to high bandwidth for the control system, which might be costly (or impossible) to achieve.

Accordingly, it is a goal of the present disclosure to provide an improved yet simple configuration of a positioning stage system, which is capable to compensate effectively for vibration induced displacements.

SUMMARY OF THE DISCLOSURE

According to a first example of the disclosure, a positioning stage system for precise and accurate movement of an object relative to a process device is proposed. In this example the positioning system comprises a stage unit for supporting the object; a drive unit for displacing the stage around at least a pivot point, as well as a vibration control unit structured to counteract external vibrations acting on the pivot point.

This ensures an effective compensation for vibration induced displacements, thus improving sic. establishing a more precise and accurate movement of the object relative to the process device.

In an example, a balanced linkage mechanism is provided which is connected to the at least one pivot point, and wherein the drive unit is structured to actuate the balanced linkage mechanism around the at least one pivot point.

An effective mitigation of any vibration induced distortion is established in an example, wherein the stage unit is mounted to a first side of the balanced linkage mechanism and the vibration control unit is mounted to a second side of the balanced linkage mechanism, with both the first side and the second side of the balanced linkage mechanism being oriented at opposite positions relative to the at least one pivot point.

Any vibration, which is induced in e.g. a floor surface on which the positioning stage system is positioned and transferred to the positioning stage system via the pivot point, will be counteracted by the vibration control unit and not affect the positioning movements of the stage unit.

In a first detailed example, the balanced linkage mechanism is composed of a balanced arm pivotally mounted to the at least one pivot point, with the stage unit being mounted to a first arm end of the balanced arm and the vibration control unit being mounted to a second arm end of the balanced arm.

In another detailed examples, the balanced linkage mechanism is composed of a multi-arm linkage mechanism, with a first balanced arm of the multi-

arm linkage mechanism pivotally mounted to a first pivot point and a second balanced arm of the multi-arm linkage mechanism pivotally mounted to a second pivot point, and a first linkage pivotally connected to first arm ends of both the first balanced arm and the second balanced arm and a second linkage pivotally connected to second arm ends of both the first balanced arm and the second balanced arm.

In both examples, the established linkage mechanisms are intrinsically insensitive to external vibrations, therefore the desired performance of accurate positioning can be achieved with no need of a high bandwidth control system.

Preferably, the drive unit is structured as a cam drive unit comprising a rotating cam interacting with the balanced linkage mechanism, yet in another example the drive unit is structured as a linear motor unit.

It is noted, that in its more effective example, the vibration control device is configured as a balanced weight.

Additionally, the at least one pivot point is mounted to the solid ground and optionally, also the drive unit is mounted to the solid ground.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will now be discussed with reference to the drawings, which show in:

Figures 1a and 1b various examples of a positioning stage system according to the state of the art;

Figure 2 a first example of a positioning stage system according to the disclosure;

Figure 3 a second example of a positioning stage system according to the disclosure;

Figure 4 a third example of a positioning stage system according to the disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

For a proper understanding of the disclosure, in the detailed description below corresponding elements or parts of the disclosure will be denoted with identical reference numerals in the drawings.

Both Figures 1a and 1b depict a first and second example of a positioning stage system according to the state of the art.

Both example of the positioning stage system according to the state of the art are denoted with reference numerals 10: and 102 respectively. Such positioning stage systems find their application in various type of metrological applications, in which the displacement and positioning of an object, e.g. a wafer substrate relative to a process device require high accuracy and reproducibility. An example of such application is the photolithography industry in which wafer substrates are being handled (picked up) by means of a stage unit and displaced in order to undergo various photolithography process steps.

In both examples as shown in Figures 1A and 1B, the positioning stage system 104-102 comprises a stage unit 11 for supporting the object. The object itself is not depicted in either Figure 1A-1B, 2 and 3, as its exact identity, functionality, size and shape is less relevant for a proper understanding of the prior art examples and the examples according to the disclosure.

The stage unit 11 can be displaced around at least a pivot point by means of a drive unit 13 relative to a process device 12. The process device 12 can be any type of process device e.g. any type of stage e.g. a metrology stage or another positioning stage. The functionality of the process device 12 is less relevant for understanding the principle of the examples according to the disclosure.

In Figure 1A the stage unit 11 can be displaced around one, single pivot point 15, which is mounted to the solid world 1. The stage unit 11 is thereto mounted to a stage unit support 14: which on one side is mounted with or incorporates the pivot point 15 connected with the solid world 1 and on the other side supports the stage unit 11. The drive unit 13 actuates the stage unit support 14: and induces a displacement of the stage unit 11 around the pivot point 15 and relative to the process device 12.

The alternative prior art example 102 of a known positioning stage system depicts a more complex stage unit support 142 which is mounted to the solid world 1 with a variety, here two pivot points 15a and 15b. The stage unit support 14; supports the stage unit 11 and proper actuation of the stage support 14: by means of the drive unit 13 results in a vertical displacement of the stage unit 11 relative to the process device 12.

A significant drawback associated with these two configurations of positioning stage systems 104-102 are vibrations, which are induced in the solid world 5 1 and transferred via the pivot points 15, 15a-15b to the stage unit 11. These vibrations are detrimental for any positioning movement of the stage unit 11 relative to the process device 12 in particular in photolithography applications where a much higher demand is given to accuracy and maximum control of the photolithography process steps.

Inertia forces generated by such vibrations cause displacements of the object e.g. a wafer substrate being mounted on the stage unit 11. These distorted displacements are to be limited as much as possible. Yet in the known systems the control system controlling the displacement of the stage unit 11 (with object) relative to the process device 12 has to be able to follow the vibration induced displacements and compensate for them. In general, this leads to high bandwidth for the control system, which might be costly (or impossible) to achieve.

Figures 2 and 3 show two examples of improved yet simple configurations of positioning stage systems according to the disclosure, which are both capable to compensate effectively for vibration induced displacements.

The positioning stage systems according to the disclosure are denoted with reference numeral 1004 (Figure 2) and 1003 (Figure 3). Analogue to the prior art examples of Figures 1A and 1B, each positioning stage system 100: and 1002 comprises a stage unit 11 for supporting an abject (wafer substrate), a process device 12, as well as a drive unit 130 structured to displace the stage unit 11 relative to the process device 12.

In both examples, reference numeral 1104 and 1102 denote specific configurations of a stage unit support that supports the stage unit 11. Stage unit supports 1104 and 1102 are actuated by the drive unit 130 and allow a displacement of the stage unit 11 relative to the process device 12 around one, single pivot point 150 or various pivot points, such as the two pivot points 1504 and 150b as shown in

Figure 3. The pivot points 150, 150a-150b are mounted to the solid world 1, like the drive unit 130.

Furthermore, each example of Figure 2 and 3 incorporates a vibration control unit 111. The vibration control unit 111 counteracts any external vibration, that is generated in the solid world 1 and acts on the single pivot point 150 (of Figure 2) or the various pivot points 150a-150b of Figure 3. In its more effective example, the vibration control device 111 is configured as a balanced weight.

This ensures an effective compensation for vibration induced displacements, thus improving sic. establishing a more precise and accurate movement of the stage unit 11 with an object relative to the process device 12.

In the example of Figure 2, the stage unit support 110: is configured as a balanced linkage mechanism 1104. It is connected to the pivot point 150, and the drive unit 130 actuates the balanced linkage mechanism 110; around the single pivot point 150. The stage unit 11 is mounted to a first side 110a of the balanced linkage mechanism 110: and the vibration control unit 111 is mounted to a second side 110b of the balanced linkage mechanism 1104. Both the first side 110a and the second side 110b of the balanced linkage mechanism 1104 are oriented or located at opposite positions relative to the pivot point 150.

As shown in the example of Figure 2, the balanced linkage mechanism 110: is formed as a balanced arm 120. The arm 120 is pivotally mounted to the pivot point 150. The balanced arm 120 has a first arm end 120a to which the stage unit 11 is mounted. The vibration control unit 111 is mounted to the other, second arm end 120b of the balanced arm 120.

Due to this configuration of the balanced linkage mechanism 110+ being formed as a balanced arm 120, any vibration, which is induced in e.g. a floor surface or solid world 1 on which the positioning stage system 1004 is positioned, and transferred to the stage unit 11 via the pivot point 150, will be effectively mitigated and counteracted by the vibration control unit 111 and will not affect the positioning movements of the stage unit 11.

The other detailed example of Figure 3, depict the balanced linkage mechanism 1102 having the configuration of a multi-arm linkage mechanism. The multi-arm linkage mechanism 1102 is pivotally connected with the ground floor / solid world 1. Reference numeral 112 denotes a first balanced arm of the multi-arm linkage mechanism 1102 that is pivotally mounted to the first pivot point 150a connected to the solid world 1. Similarly, a second balanced arm 113 is pivotally connected or mounted in a hinged manner to a second pivot point 150b.

Both first arm ends 112a and 113a of both the first balanced arm 112 and the second balanced arm 113 are interconnected with each other by means of a first linkage 115a through pivot or hinge points 114a and 114c. Likewise, a second linkage is provided that pivotally through pivot or hinge points 114b-114d interconnects the second arm ends 112b-113b of both the first balanced arm 112 and the second balanced arm 113.

The drive unit 130 may be structured as a cam drive unit. In such configuration, a rotating cam 131 is provided that has a cam surface 131a that interacts with the balanced linkage mechanism 110; and 110:.

In another example as shown in Figure 4, the drive unit can be structured as a linear motor unit 1302. The linear motor unit 1302 has an actuator 133 which directly acts on the stage unit 11. Accordingly, also in this example the linear motor unit 130; is capable of actuating the balanced linkage mechanism 110: around the at least one pivot point 150. It is evident that the linear motor unit 1302 acting directly on the stage unit 11 can also be implemented in the example of the balanced linkage mechanism 110; of Figure 3.

In the examples of Figures 2-3-4, the balanced linkage mechanisms 1104-1102 are intrinsically insensitive to external vibrations. Any vibration induced in the solid world 1 and transferred via the pivot point 150 or pivot points 150a-150b towards the positioning stage systems 1001-1002 will not adversely affect the displacement of the stage unit 11 relative to the process device 12 by the drive unit 130. These external vibrations are effectively counteracted by the vibration control unit 111, which is mounted in the linkage mechanisms 1104-1102 in a balanced manner relative to the stage unit 11.

Accordingly, due to the effective vibration counteracting behavior of the vibration control unit 111 the vibrations do not disrupt the proper actuation of the balanced linkage mechanisms 110:-1102 and displacement of the stage unit 11 with an object by means of the drive unit 130. Thus, the drive unit 130 is able to perform the desired and accurate positioning of the stage unit 11 relative to the process device 12 irrespective of the vibrations exerted on the pivot points 150, 150a-150b.

Furthermore, due to this effective vibration counteracting functionality, the actuation of the stage unit 11 can be achieved with no need of a high bandwidth control system.

In addition to the examples disclosed above, it is worth mentioning that this effective vibration counteracting functionality not necessarily cancels any vibration completely, yet is also applicable for a partial balancing of vibrations, hence not cancelling the vibrations completely but significantly reducing them.

LIST OF REFERENCE NUMERALS USED

1 solid ground 104-102 positioning stage system (15! and 2"? state of the art examples) 11 stage unit for supporting the object 12 process device, such as a metrology stage or another positioning stage 13 drive unit 141-142 mounting unit (15t and 2" state of the art examples) 15 pivot point (1% state of the art example) 15a-15b pivot points (29 state of the art example) 1004-100; positioning stage system (1° and 2"? examples acc. to the disclosure) 1104-1102 balanced linkage mechanism (1% and 2" examples acc. to the disclosure) 1104 first side of balanced linkage mechanism 110b second side of balanced linkage mechanism 111 vibration control unit / balanced weight 112 balanced arm of balanced linkage mechanism (15t example) 1124 first arm end of balanced arm 112 112b second arm end of balanced arm 112 1124 first balanced arm of balanced linkage mechanism (29 example) 1122 second balanced arm of balanced linkage mechanism {2"4 example) 112a, first arm end of first/second balanced arm 112b, second arm end of first/second balanced arm 114a-114d first-second-third-fourth linkage pivot point 115a first linkage 115b second linkage 130-130: drive unit {acc. to the disclosure)

131 rotating cam 131a cam surface 132 rotating axis 133 actuator of linear motor 1302 150 pivot point (15t example acc. to the disclosure) 150a-150b pivot points (2" example acc. to the disclosure)

Claims

CONCLUSIONS

1. A positioning platform system for precise and accurate displacement of an object relative to a processing device, the positioning system comprising: a platform unit for supporting the object; a drive unit for displacing the platform unit about at least one pivot point; and a vibration control unit adapted to counteract external vibrations acting on the pivot point.

2. The positioning platform system of claim 1, further comprising a balanced coupling mechanism connected to the at least one pivot point, and wherein the drive unit is configured to actuate the balanced coupling mechanism about the at least one pivot point.

3. The positioning platform system according to claim 2, wherein the platform unit is disposed on a first side of the balanced coupling mechanism and the vibration control unit is disposed on a second side of the balanced coupling mechanism, both the first side and the second side of the balanced coupling mechanism being disposed at opposite positions with respect to the at least one pivot point.

4. The positioning platform system of claim 2 or 3, wherein the balanced linkage mechanism comprises a balanced arm pivotally mounted on the at least one pivot point, the platform unit being mounted on a first arm end of the balanced arm and the vibration control unit being mounted on a second arm end of the balanced arm.

5. The positioning platform system according to claim 2 or 3, wherein the balanced linkage mechanism is composed of a multi-arm linkage mechanism, a first balanced arm of the multi-arm linkage mechanism being rotatably disposed on a first pivot point and a second balanced arm of the multi-arm linkage mechanism being rotatably disposed on a second pivot point, and a first linkage mechanism being rotatably connected to the first arm ends of both the first balanced arm and the second balanced arm and a second linkage mechanism being rotatably connected to the second arm ends of both the first balanced arm and the second balanced arm.

6. The positioning platform system according to any one of claims 2 to 5, wherein the drive unit is configured as a cam drive unit comprising a rotating cam cooperating with the balanced coupling mechanism.

7. The positioning table system according to any one of claims 2 to 5, wherein the drive unit is constructed as a linear motor unit.

8. The positioning platform system according to any of the preceding claims, wherein the vibration control unit is configured as a balanced weight.

9. The positioning table system according to any one of the preceding claims, wherein the at least one pivot point is placed on the fixed world.

10. The positioning table system according to any one of the preceding claims, wherein the drive unit is placed on the fixed world.