US-12619168-B2 - Systems and methods for thermally stable mounting of optical columns

Abstract

Systems and methods are disclosed for stabilizing an optical column. One system can include an optical column; a frame configured to support the optical column, the frame having a first coefficient of thermal expansion (CTE); and a subframe configured to be coupled to the optical column in at least two places by a first anchor and a second anchor to stabilize the optical column against a displacement or a rotation caused by thermal expansion in the frame or the optical column, the subframe having a second CTE lower than the first CTE.

Inventors

• Jasper Winters
• Erwin John Van Zwet
• Marcus Johannes van der Lans
• Pieter Willem Herman De Jager
• Emiel Anton VAN DE VEN

Assignees

• ASML NETHERLANDS B.V.

Dates

Publication Date

20260505

Application Date

20240117

Priority Date

20210721

Claims (19)

1. 1 . A system comprising: an optical column; a frame configured to support the optical column, the frame having a first coefficient of thermal expansion (CTE), wherein the optical column is suspended under a lateral frame section of the frame at a distal end of the optical column; and a subframe configured to be coupled to the optical column in at least two places by a first anchor and a second anchor to stabilize the optical column against a displacement or a rotation caused by thermal expansion in the frame or the optical column, the subframe having a second CTE lower than the first CTE.
2. 2 . The system of claim 1 , wherein and the subframe is coupled to the optical column at a proximal end of the optical column.
3. 3 . The system of claim 1 , wherein the subframe is coupled to the optical column at approximately a level of a micro-lens array located in the optical column.
4. 4 . The system of claim 1 , wherein the first anchor and the second anchor are configured to couple to the subframe and the optical column to stabilize the optical column against displacements in a plane and against the rotation around a longitudinal axis through the optical column perpendicular to the plane.
5. 5 . The system of claim 1 , further comprising: a plurality of optical columns; and a plurality of first anchors and a plurality of second anchors, each of the plurality of the first and second anchors coupled to a corresponding optical column in the plurality of the optical columns.
6. 6 . The system of claim 1 , wherein the first anchor is configured to stabilize against the displacement of the optical column in at least two directions perpendicular to an axis of the optical column.
7. 7 . The system of claim 1 , wherein the second anchor is coupled to the optical column at a different location than the first anchor, thereby resisting the rotation of the optical column around a longitudinal axis.
8. 8 . The system of claim 1 , wherein the subframe further comprises a third anchor, wherein the coupling in the at least two places is performed by the first anchor and further by the third anchor.
9. 9 . The system of claim 8 , wherein the third anchor is configured to stabilize against the displacement of the optical column being in at least two directions perpendicular to a longitudinal axis of the optical column, wherein the third anchor extends at least partially opposite a first direction of the two directions and extends at least partially in a second direction of the two directions.
10. 10 . The system of claim 1 , wherein the subframe further comprises a first lateral subframe section, the first anchor and the second anchor coupled to the first lateral subframe section.
11. 11 . The system of claim 1 , wherein the frame further comprises two frame vertical sections symmetrically located at opposing ends of a lateral frame section to allow positioning of the optical column between them, wherein the subframe is coupled to the two vertical frame sections thereby causing the subframe to be centered with the frame.
12. 12 . The system of claim 1 , wherein the subframe is configured to be coupled to an external body to resist a vertical displacement.
13. 13 . The system of claim 1 , further comprising a Z actuator coupled to the optical column and configured to compensate for a vertical displacement of the optical column.
14. 14 . The system of claim 1 , wherein the system is configured to manufacture flat-panel displays.
15. 15 . A method for stabilizing an optical column against a displacement or a rotation, the method comprising: supporting an optical column with a frame having a first coefficient of thermal expansion (CTE), wherein the optical column is suspended under a lateral frame section of the frame at a distal end of the optical column; and coupling the optical column to a subframe in at least two places by a first anchor and a second anchor to stabilize the optical column against a displacement or a rotation caused by thermal expansion in the frame or the optical column, the subframe having a second CTE lower than the first CTE.
16. 16 . The method of claim 15 , further comprising utilizing the first anchor and the second anchor to stabilize the optical column against displacements in a plane and against the rotation around a longitudinal axis through the optical column perpendicular to the plane.
17. 17 . The method of claim 15 , further comprising coupling the subframe to the optical column at approximately a level of a micro-lens array located in the optical column.
18. 18 . The method of claim 15 , further comprising coupling the second anchor to the optical column at a different location than the first anchor, thereby resisting the rotation of the optical column around a longitudinal axis.
19. 19 . The method of claim 15 , further comprising coupling a third anchor to the subframe, wherein the coupling in the at least two places is performed by the first anchor and further by the third anchor.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority of International application PCT/EP2022/066594, filed on 17 Jun. 2022, which claims priority of EP application Ser. No. 21/186,947.4, filed on 21 Jul. 2021. These applications are incorporated herein by reference in their entireties. TECHNICAL FIELD The description herein relates generally to maskless manufacturing and patterning processes. More particularly, the disclosure includes systems and methods for stabilizing optical columns. BACKGROUND A lithographic projection apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such a case, a patterning device (e.g., a mask) may contain or provide a pattern corresponding to an individual layer of the IC (“design layout”), and this pattern can be transferred onto a target portion (e.g. comprising one or more dies) on a substrate (e.g., silicon wafer) that has been coated with a layer of radiation-sensitive material (“resist”), by methods such as irradiating the target portion through the pattern on the patterning device. In general, a single substrate contains a plurality of adjacent target portions to which the pattern is transferred successively by the lithographic projection apparatus, one target portion at a time. In one type of lithographic projection apparatuses, the pattern on the entire patterning device is transferred onto one target portion in one go; such an apparatus may also be referred to as a stepper. In an alternative apparatus, a step-and-scan apparatus can cause a projection beam to scan over the patterning device in a given reference direction (the “scanning” direction) while synchronously moving the substrate parallel or anti-parallel to this reference direction. Different portions of the pattern on the patterning device are transferred to one target portion progressively. Since, in general, the lithographic projection apparatus will have a reduction ratio M (e.g., 4), the speed F at which the substrate is moved will be 1/M times that at which the projection beam scans the patterning device. More information with regard to lithographic devices can be found in, for example, U.S. Pat. No. 6,046,792, incorporated herein by reference. Prior to transferring the pattern from the patterning device to the substrate, the substrate may undergo various procedures, such as priming, resist coating and a soft bake. After exposure, the substrate may be subjected to other procedures (“post-exposure procedures”), such as a post-exposure bake (PEB), development, a hard bake and measurement/inspection of the transferred pattern. This array of procedures is used as a basis to make an individual layer of a device, e.g., an IC. The substrate may then undergo various processes such as etching, ion-implantation (doping), metallization, oxidation, chemo-mechanical polishing, etc., all intended to finish off the individual layer of the device. If several layers are required in the device, then the whole procedure, or a variant thereof, is repeated for each layer. Eventually, a device will be present in each target portion on the substrate. These devices are then separated from one another by a technique such as dicing or sawing, whence the individual devices can be mounted on a carrier, connected to pins, etc. Thus, manufacturing devices, such as semiconductor devices, typically involves processing a substrate (e.g., a semiconductor wafer) using a number of fabrication processes to form various features and multiple layers of the devices. Such layers and features are typically manufactured and processed using, e.g., deposition, lithography, etch, chemical-mechanical polishing, and ion implantation. Multiple devices may be fabricated on a plurality of dies on a substrate and then separated into individual devices. This device manufacturing process may be considered a patterning process. A patterning process involves a patterning step, such as optical and/or nanoimprint lithography using a patterning device in a lithographic apparatus, to transfer a pattern on the patterning device to a substrate and typically, but optionally, involves one or more related pattern processing steps, such as resist development by a development apparatus, baking of the substrate using a bake tool, etching using the pattern using an etch apparatus, etc. As noted, lithography is a central step in the manufacturing of device such as ICs, where patterns formed on substrates define functional elements of the devices, such as microprocessors, memory chips, etc. Similar lithographic techniques are also used in the formation of flat panel displays, micro-electro mechanical systems (MEMS) and other devices. As semiconductor manufacturing processes continue to advance, the dimensions of functional elements have continually been reduced while the amount of functional elements, such as transistors, per device has been steadily increasing over decades, following a trend referred to as “Moore's law.