TWI861105B - Reticle cage actuator with shape memory alloy and magnetic coupling mechanisms - Google Patents

Abstract

Embodiments herein describe methods and safety devices used to provide support for an object. A safety device includes a driving side comprising a driving motor and a driven side. The driven side of the safety device includes a housing having a rotating shaft extending along a length of the housing and a safety latch. The driven side is coupled to the driving motor via a non-contact, magnetic coupling device at a first end of the rotating shaft, and the safety latch is coupled to a second end of the rotating shaft opposite from the first end of the rotating shaft. The driving motor is configured to cause rotation in a radial direction of the safety latch on the driving side via the non-contact, magnetic coupling device.

Description

Multiplying mask cage actuator with shape memory alloy and magnetic coupling mechanism

The present invention relates to safety mechanisms, such as a zoom mask cage actuator and a magnetic coupling mechanism for holding patterned devices in a lithography system.

A lithographic apparatus is a machine that applies a desired pattern to a substrate, typically to a target portion of the substrate. A lithographic apparatus may be used, for example, in the manufacture of integrated circuits (ICs). In this case, a patterning device, alternatively referred to as a mask or reticle, may be used to produce the circuit pattern to be formed on individual layers of the IC. This pattern may be transferred to a target portion (e.g., a portion containing a die, one or several dies) on a substrate (e.g., a silicon wafer). Transfer of the pattern is typically performed by imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. Generally, a single substrate will contain a network of adjacent target portions that are patterned in sequence. Known lithography devices include so-called steppers, in which each target portion is irradiated by exposing the entire pattern onto the target portion at once, and so-called scanners, in which each target portion is irradiated by scanning the pattern in a given direction (the "scanning" direction) by means of a radiation beam while simultaneously scanning the target portion parallel or antiparallel to this scanning direction. It is also possible to transfer the pattern from the patterned device to the substrate by embossing the pattern onto the substrate.

Lithography is widely recognized as one of the key steps in the manufacture of ICs and other devices and/or structures. However, as the size of features produced using lithography becomes smaller and smaller, lithography is becoming a more critical factor in enabling the manufacture of small ICs or other devices and/or structures.

To project a pattern onto a substrate, a lithography apparatus may use electromagnetic radiation. The wavelength of this radiation determines the minimum size of features that can be formed on the substrate. Lithography apparatus using extreme ultraviolet (EUV) radiation with a wavelength in the range of 4 to 20 nm (e.g. 6.7 nm or 13.5 nm) can be used to form smaller features on a substrate than lithography apparatus using radiation with a wavelength of, for example, 193 nm.

Lithography apparatus using EUV radiation may require that the EUV radiation beam path or at least a substantial portion of the EUV radiation beam path must be maintained in a vacuum during lithography operations. In such vacuum regions of the lithography apparatus, electrostatic chucks may be used to clamp objects (e.g., patterned devices and/or substrates) to structures of the lithography apparatus (e.g., patterned device stages and/or substrate stages), respectively.

It is known that patterned devices such as reticles are extremely expensive. Therefore, extreme caution should be exercised when handling reticles within a lithography apparatus. Although reticles are typically clamped to a chuck structure, it is desirable to include a safety mechanism in the event of clamping failure. Otherwise, the reticles may fall, causing damage not only to the reticles themselves, but also to other expensive optical components within the lithography apparatus.

It is known that safety designs can be used to ensure that patterned devices such as reticle do not inadvertently fall from a chuck (e.g., reticle stage). Such designs typically use electromagnets to open or close metal arms to "catch" the reticle if it falls. Such designs are not very efficient because they require large motors to generate the force necessary to open the arms, and also require constant power consumption to hold the arms in the open position. Due to the power requirements, safety designs also require effective cooling of the electromagnets to dissipate heat within the system. In addition, if the power is cut off during operation, the arm of the safety latch powered by the solenoid will automatically close and may damage the zoom mask during operations such as zoom mask exchange.

Therefore, there is a need to provide new devices and methods for enhancing the safety mechanism of a zoom mask in a reliable and efficient manner. The embodiments herein describe systems, devices and methods for an improved safety device that does not require an electromagnet to hold the zoom mask. The present invention provides a safety device that utilizes permanent non-contact magnetic coupling to facilitate a rotational actuator mechanism to support a zoom mask in a lithography system. The magnetic coupling allows the axis of the safety device to rotate between the drive carrier side and the chuck side without physical contact, while minimizing power requirements via a dual-stable actuator mechanism. The present invention also includes devices and methods for shape memory alloys (SMA) and compression spring activated actuators for zoom mask safety. By applying an electric current or heat to the shape memory alloy of the security device, the safety latch of the security device can be actuated to an "open" or "closed" position in response to the compression of a spring activated by the change in the shape memory alloy in the security device.

In some embodiments, a safety device for providing support for an object includes a driving side and a driven side. The driving side includes a driving motor. The driven side includes a housing having a rotating shaft extending along the length of the housing, and a safety latch, wherein the driven side is coupled to the driving motor at a first end of the rotating shaft via a non-contact magnetic coupling device. The safety latch is coupled to a second end of the rotating shaft opposite the first end of the rotating shaft. The driving motor is configured to rotate the safety latch in a radial direction on the driving side via a non-contact magnetic coupling device.

In some embodiments, a lithography apparatus includes an illumination system, a support structure, a projection system, and one or more safety devices. The illumination system conditions a radiation beam. The support structure is configured to support a patterning device capable of imparting a pattern to the radiation beam in a cross-section of the radiation beam to form a patterned radiation beam. The projection system is configured to project the patterned radiation beam onto a target portion of a substrate. One or more safety devices are coupled to the support structure and each includes a driving side and a driven side. The driving side of the one or more safety devices includes a drive motor. The driven side of one or more safety devices includes a housing having a rotating shaft extending along the length of the housing, and a safety latch, wherein the driven side is coupled to a drive motor at a first end of the rotating shaft via a contactless magnetic coupling device. The safety latch is coupled to a second end of the rotating shaft opposite the first end of the rotating shaft. The drive motor is configured to rotate the safety latch in a radial direction on the driving side via the contactless coupling device.

In some embodiments, a method includes using a security device for supporting a patterned device, the security device having an actuator including at least one shape memory alloy, a security latch, and at least one spring coupled to the security latch. The security latch includes a foot portion at a distal end of the security latch, wherein the foot portion is configured to serve as a contact point for the patterned device. The method also includes applying a current to at least one shape memory alloy of the security device to activate the at least one shape memory alloy, and actuating the security latch from a first position below the patterned device to a second position in response to the activation of the at least one shape memory alloy.

Other aspects, features and advantages, as well as the structure and operation of various embodiments of the present invention are described in detail below with reference to the accompanying drawings. It should be noted that the present invention is not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Based on the teachings contained herein, additional embodiments will be apparent to those skilled in the relevant art.

10: Faceted field mirror device

11: Faceted pupil mirror device

13: Mirror

14: Mirror

200: Zoom mask stage/chuck

201: Buffer device

202: Top stage surface

204: Bottom stage surface

206: Side stage surface

208: Zoom mask

212: First encoder

214: Second encoder

300: Safety device

401:Drive side

402: Driven side

404: Driving motor

406: Magnetic coupling

406a:Driver assembly

406b: Driven component

408: Shell

410: Axis

412: Security latch

414: Foot support area

416: Security buffer

418:Sensor

420: Target

422: Particle seal

424: Upper particle seal

426: Bearings

428: Lower end particle seal

600: Face-to-face magnetic coupling configuration

610: Coaxial magnetic coupling configuration

620: Magnetic coupling surface

625: Magnet

802: Shape memory alloy

802: Actuator mechanism

804: Pin connector

806: Spring

808: Security latch

809: Zoom mask support

810: Actuator mechanism

811: Current

900: Actuator mechanism

902: Shape memory alloy

906: Spring

908: Safety latch

909: Zoom mask support foot

910: Actuator mechanism

1000: Safety device

1002: Shape memory alloy

1004: Driving motor

1006: Spring

1008: Safety latch

1009: Zoom mask support

1010: Safety device

1020: Safety device

1030: Clamp

1100:Methods

1102: Operation

1104: Operation

1106: Operation

1108: Operation

1110: Operation

B:Radiation beam

B': Radiation beam

IL: Lighting system

LA: Lithography System

MA: Patterned device

MT: Support structure

PS: Projection system

SO: Radiation source

W: Substrate

WT: Substrate table

The accompanying drawings, which are incorporated herein and form part of this specification, illustrate the invention and, together with the implementation method, further serve to explain the principles of the invention and enable those skilled in the relevant art to make and use the invention.

FIG1 is a schematic diagram of a lithography apparatus according to an embodiment of the present invention.

FIG2 is a three-dimensional schematic illustration of a zoom mask stage according to an embodiment of the present invention.

Figure 3 is a top plan view of the zoom mask stage in Figure 2.

Figures 4A and 4B are schematic illustrations of a safety device according to an embodiment of the present invention.

FIG. 5 is a schematic illustration showing an isometric view of the security device of FIG. 4A and FIG. 4B according to an embodiment of the present invention.

Figures 6A, 6B and 6C are schematic illustrations of example magnetic coupling configurations for a safety device according to an embodiment of the present invention.

Figure 7 is a schematic illustration of a rotary safety latch according to an embodiment of the present invention.

FIG. 8A and FIG. 8B are schematic illustrations showing front views of a shape memory alloy (SMA) actuator mechanism according to an embodiment of the present invention.

FIG. 9A and FIG. 9B are schematic illustrations showing a top view of a shape memory alloy (SMA) actuator mechanism according to an embodiment of the present invention.

Figures 10A to 10D are schematic illustrations of a shape memory alloy actuator and a safety device for multiplying mask safety according to an embodiment of the present invention.

FIG. 11 is a schematic illustration of a flow chart for operating a security device for supporting a patterned device according to an embodiment of the present invention.

Features and advantages of the present invention will become more apparent from the following detailed description in conjunction with the accompanying drawings, in which the same reference numerals identify corresponding elements throughout. In the drawings, the same figure numerals generally indicate identical, functionally similar, and/or structurally similar elements. Unless otherwise indicated, the drawings provided throughout the present invention should not be interpreted as being drawn to scale.

This specification discloses one or more embodiments incorporating features of the present invention. The disclosed embodiments are merely illustrative of the present invention. The scope of the present invention is not limited to the disclosed embodiments. The present invention is defined by the scope of the patent application attached hereto.

The embodiments described and references to "an embodiment", "an embodiment", "an example embodiment" and the like in this specification indicate that the embodiments described may include specific features, structures or characteristics, but each embodiment may not necessarily include the specific features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when a specific feature, structure or characteristic is described in conjunction with an embodiment, it should be understood that whether or not it is explicitly described, it is within the scope of knowledge of those skilled in the art that the feature, structure or characteristic is affected by the combination with other embodiments.

For ease of description, spatially relative terms (such as "under", "beneath", "lower", "above", "on", "upper", and the like) may be used herein to describe the relationship of one element or feature to another element or feature illustrated in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be otherwise oriented (rotated 90 degrees or in other orientations) and the spatially relative descriptors used herein may be interpreted accordingly.

As used herein, the term "approximately" indicates a value of a given quantity that may vary based on a particular technology. Based on a particular technology, the term "approximately" may indicate a value of a given quantity that varies, for example, within 10 to 30% of the value (e.g., ±10%, ±20%, or ±30% of the value).

Embodiments of the present invention may be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the present invention may also be implemented as instructions stored on a machine-readable medium that can be read and executed by one or more processors. Machine-readable media may include any mechanism for storing or transmitting information in a form that can be read by a machine (e.g., a computing device). For example, machine-readable media may include: read-only memory (ROM); random access memory (RAM); disk storage media; optical storage media; flash memory devices; electrical, optical, acoustic, or other forms of propagation signals (e.g., carrier waves, infrared signals, digital signals, etc.), and others. Additionally, firmware, software, routines, and/or instructions may be described herein as performing certain actions. However, it should be understood that such descriptions are for convenience only and that such actions are actually caused by a computing device, processor, controller, or other device executing the firmware, software, routines, instructions, etc., and that in performing such operations may cause actuators or other devices to interact with the physical world.

However, before describing such embodiments in more detail, an example environment in which embodiments of the present invention may be implemented is presented for guidance.

Example lithography system

FIG1 shows a lithography system including a radiation source SO and a lithography apparatus LA. The radiation source SO is configured to generate an EUV radiation beam B and supply the EUV radiation beam B to the lithography apparatus LA. The lithography apparatus LA includes an illumination system IL, a support structure (e.g., a mask stage) MT configured to support a patterned device MA (e.g., a mask), a projection system PS, and a substrate stage WT configured to support a substrate W. In general, the movement of the support structure MT can be achieved by means of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), as further described below.

The illumination system IL is configured to condition the EUV radiation beam B before the EUV radiation beam B is incident on the patterned device MA. In addition, the illumination system IL may include a faceted field mirror device 10 and a faceted pupil mirror device 11. The faceted field mirror device 10 and the faceted pupil mirror device 11 together provide an EUV radiation beam B having a desired cross-sectional shape and a desired intensity distribution. In addition to or in place of the faceted field mirror device 10 and the faceted pupil mirror device 11, the illumination system IL may include other mirrors or devices

After being conditioned in this way, the EUV radiation beam B interacts with the patterned device MA. As a result of this interaction, a patterned EUV radiation beam B' is generated. The projection system PS is configured to project the patterned EUV radiation beam B' onto the substrate W. For this purpose, the projection system PS may comprise a plurality of mirrors 13, 14, which are configured to project the patterned EUV radiation beam B' onto the substrate W held by the substrate table WT. The projection system PS may apply a reduction factor to the patterned EUV radiation beam B', thereby forming an image having features that are smaller than the corresponding features on the patterned device MA. For example, a reduction factor of 4 or 8 may be applied. Although the projection system PS is illustrated in FIG. 1 as having only two mirrors 13, 14, the projection system PS may include a different number of mirrors (e.g., six or eight mirrors).

The substrate W may include a previously formed pattern. In this case, the lithography device LA aligns the image formed by the patterned EUV radiation beam B' with the pattern previously formed on the substrate W.

A relative vacuum, i.e. a small amount of gas (e.g. hydrogen) at a pressure much lower than atmospheric pressure, may be provided in the radiation source SO, in the illumination system IL and/or in the projection system PS.

The radiation source SO may be a laser produced plasma (LPP) source, a discharge produced plasma (DPP) source, a free electron laser (FEL) or any other radiation source capable of generating EUV radiation.

Example of zoom mask stage and safety device system

FIG. 2 and FIG. 3 show schematic illustrations of an exemplary reticle stage 200 according to some embodiments of the present invention. The reticle stage 200 may include a top stage surface 202, a bottom stage surface 204, a side stage surface 206, a reticle 208, and a safety device 300. In some embodiments, the reticle stage 200 with the reticle 208 may be implemented in a lithography apparatus LA. For example, the reticle stage 200 may represent a support structure MT and the reticle 208 may represent a patterning device MA in the lithography apparatus LA. In some embodiments, the reticle 208 and the plurality of safety devices 300 may be disposed on the top stage surface 202. For example, as shown in FIG. 2 , the zoom mask 208 may be disposed at the center of the top stage surface 202, and the safety device 300 may be disposed adjacent to each corner of the zoom mask 208.

In some lithography apparatuses (e.g., lithography apparatus LA), a zoom mask stage or chuck 200 may be used to hold and position a zoom mask 208 for scanning or patterning operations. Zoom mask stage 200 requires a strong drive, a large counterweight, and a load-bearing frame to support itself. Zoom mask stage 200 has a large inertia and may weigh more than 500 kg to push and position a zoom mask 208 weighing approximately 0.5 kg. To achieve the reciprocating motion of zoom mask 208 typically found in lithography scanning or patterning operations, acceleration and deceleration forces may be provided by a linear motor driving zoom mask stage 200.

During a sudden failure of the reticle stage 200, such as due to a large power loss or a severe system failure, the acceleration and deceleration forces of the reticle stage 200 may be transferred to the reticle 208 and cause the reticle to crash. The reticle 208 may crash into other components of the reticle stage 200, causing damage to the reticle 208 and/or other nearby components. The reticle 208 may crash at relatively high forces (i.e., high accelerations), depending on the pre-crash motion and momentum of the reticle stage 200. Softer zoom mask deflections may cause metal fractures (e.g., pattern damage), while stiffer zoom mask deflections may cause glass fractures (e.g., cracks in the zoom mask). Current approaches use some form of safety mechanism to reduce or mitigate the force of the zoom mask during impact. However, due to the higher impact stress (force) of the zoom mask under worst case impact, the zoom mask and/or current safety mechanisms may also be damaged.

One possible solution is to position a safety mechanism (e.g., safety device 300) around the zoom mask 208 to act as a shock absorber to reduce the impact force of the zoom mask 208 during a collision. For example, a buffer device 201 with a shock absorber can be used around the zoom mask 208 to absorb possible forces or shocks caused by the collision, so that damage to the zoom mask 208 and the safety device 300 can be completely reduced or eliminated. According to an embodiment, the safety devices 300 can also each include a safety latch (not shown in the figure), which is appropriately rotated under the zoom mask 208 so that the safety latch prevents the zoom mask 208 from falling from the zoom mask stage 200. The zoom mask 208 can be restrained by four safety devices 300 (e.g., disposed adjacent to the corners of the zoom mask 208). In one embodiment, the safety devices 300 can function similarly to a "cage" used to prevent objects from being displaced or dropped. When the safety devices 300 are used to provide emergency support for the zoom mask, the safety devices 300 can be collectively referred to as a zoom mask cage, but the safety devices 300 can also be used to support other types of patterned devices or any other type of clamped objects.

In some embodiments, as shown in FIGS. 2 and 3, the zoom mask stage 200 may include a first encoder 212 and a second encoder 214 for positioning operations. For example, the first encoder 212 and the second encoder 214 may be interferometers. The first encoder 212 may be attached along a first direction, such as a lateral direction of the zoom mask stage 200 (i.e., X direction), and the second encoder 214 may be attached along a second direction, such as a longitudinal direction of the zoom mask stage 200 (i.e., Y direction). In some embodiments, as shown in FIGS. 2 and 3, the first encoder 212 may be orthogonal to the second encoder 214.

The safety device 300 can be configured to stabilize and reduce damage to the zoom mask 208 during a collision. The safety device 300 can be configured to evenly distribute the impact force of the zoom mask 208 during a collision. In some embodiments, a plurality of safety devices 300 can be disposed in the top stage surface 202 and can be arranged around the periphery of the zoom mask 208. For example, a plurality of safety devices 300 can be disposed adjacent to each corner of the zoom mask 208 so that the impact force of the zoom mask 208 is evenly distributed over a plurality of impact locations.

In some embodiments, the safety device 300 can be used to hold the reticle 208 (e.g., a reticle with a safety latch) in place, such as during a reticle swap operation or manual recovery of the reticle 208. The safety device 300 is also suitable for preventing the reticle 208 from being displaced in the Z direction if it is disengaged from an electrostatic fixture that holds the reticle during scanning.

Example design of a safety device with magnetic coupling

FIG. 4A and FIG. 4B illustrate example views of a security device 300 according to an embodiment of the present invention. Specifically, FIG. 4A illustrates a side view of the security device 300, and FIG. 4B illustrates a cross-sectional view of the security device 300. As discussed above in FIG. 2-3, one or more security devices 300 may be disposed around the zoom mask 208 and coupled to a chuck (e.g., the zoom mask stage 200).

The safety device 300 includes a driving side 401 (e.g., on a carrier) and a driven side 402 (e.g., on a chuck). Specifically, the driving side 401 includes a moving component of the safety device 300, and the driven side 402 includes a driven component that responds to the movement of the driving side 401. The driving side 401 includes a driving motor 404, a driving component 406a, and a sensor 418.

In some embodiments, sensor 418 includes a position sensor configured to sense the proximity or position of an object or target (e.g., target 420). For example, sensor 418 can be a capacitive sensor, an inductive sensor, an optical reflective sensor, a broken beam sensor. In some embodiments, sensor 418 can be located on the driving side 401 (e.g., a carrier), and the object sensed by sensor 418 can be located on the driven side 402 (e.g., a chuck). In other embodiments, both sensor 418 and the object sensed by sensor 418 can be located on the driven side 402 (e.g., a chuck). In some cases, if the sensor 418 and the object are located on different sides of the security device 300 (e.g., the sensor 418 is located on the driving side 401 and the object is located on the slave side 402, or vice versa), the movement of the slave side 402 and the driving side 401 can affect the sensor data. By positioning both the sensor 418 and the object on the slave side 402, the slave side 402 and the driving side 401 can move relative to each other without affecting the sensor data.

The drive motor 404 is a component that moves the safety device 300 and controls the movement of the safety device 300. In some embodiments, the drive motor 404 can be a rotary motor, an actuator and/or a direct drive, a bi-stable actuator. Specifically, the drive motor 404 drives or actuates a drive assembly 406a, which is part of the magnetic coupling device 406. Alternatively, a rotary solenoid can be used instead of a motor or another electric rotary motor with a braking mechanism. The bi-stable nature of the drive motor 404 means that the movement of the motor only occurs when the power is insufficient. When the drive motor 404 is fixed in a given position, it does not consume power. The driving motor 404 can be a piezoelectric motor or a DC motor.

The magnetic coupling device 406 provides non-contact permanent magnetic coupling for the safety device 300. The magnetic coupling device 406 includes two components: a driving component 406a and a driven component 406b. The two components 406a and 406b have permanent magnets facing each other but not touching each other. For example, the driving component 406a and the driven component 406b can be physically separated by a distance of about 1 to 4 mm. The attractive force between the permanent magnets of the driving component 406a and the driven component 406b allows the driving side 401 to drive or move the driven side 402 of the safety device in a rotational manner.

The driven side 402 includes a driven component 406b, a housing 408, a shaft 410, a safety buffer 416, a safety latch 412, a foot area 414, a safety buffer 416, and a target 420. The driven component 406b reacts to the movement of the driving component 406a via the magnetic coupling device 406, so that mechanical energy is transmitted to the driven side 402 in a non-contact manner. The housing 408 of the driven side 402 can have a longest length along the Z axis, and the housing 408 can be provided to protect the moving components disposed inside. The housing 408 can be an injection molded material, such as a polymer material, or the housing 408 can be a machined metal. In some embodiments, the length of the housing 408 along the Z direction may be approximately 20 to 70 mm.

The housing 408 includes a shaft 410 attached to the drive motor 404 via a magnetic coupling device 406. Specifically, the shaft 410 can be disposed within the housing 408, and the magnetic coupling device 406 can be coupled to one end of the shaft 410 outside the housing 408. The shaft 410 can extend along the length of the housing 408.

A safety buffer 416 may also be included as part of the motor design and disposed within the driven side 402 of the safety device. Any type of bushing or bearing design may be used in the safety buffer design. According to some embodiments, one or more safety buffers 416 may be included in the safety device 300 to act as a stop mechanism for the zoom mask in the X and Y directions once the zoom mask loses its grip on the driven side 402 (e.g., a chuck). The safety buffer 416 is described in more detail in U.S. Application No. 62/768,161, which is incorporated herein by reference in its entirety.

The safety device 300 also includes a safety latch 412 coupled to the end of the shaft 410 opposite the end coupled to the magnetic coupling device 406. The safety latch 412 rotates along the rotation axis 410. In some embodiments, the safety latch 412 can rotate a full 360 degrees around an axis parallel to the Z direction below the housing 408. The safety latch 412 extends radially outward from the shaft 410 and can have a length of less than 60 mm. For example, the safety latch 412 can have a length greater than 10 mm and less than 60 mm. The exact illustrated design of the safety latch 412 is only an example and is not intended to be limiting. The safety latch 412 may include two or more separate beams as illustrated in FIG. 4A, FIG. 4B, or FIG. 5, or it may be a solid piece.

In some embodiments, the foot region 414 may be disposed at a distal end of the safety latch 412. The foot region 414 may be referred to as a safety foot or a zoom mask foot. The foot region 414 may be substantially flat and designed to contact a portion of a patterned device (e.g., a zoom mask). According to some embodiments, the foot region 414 is the only portion of the safety latch 412 that will have any contact with the patterned device if the device were to fall from its clamping position in the Z direction.

The cross-sectional view of FIG. 4B further illustrates additional components of the safety device 300, including a particle-particle seal 422, an upper particle seal 424, a bearing 426, and a lower particle seal 428. The bearing 426 includes a ceramic component that withstands the friction between the rotating parts in the housing 408. The particle seals 422, 424, and 428 can be designed so that particles generated from the moving parts during the rotation of the safety latch 412 remain trapped in the object 408 and are not expelled into the space around the safety device 300. In some embodiments, the upper particle seal 424, the bearing 426, and the lower particle seal 428 can be disposed in the housing 408 of the safety device.

FIG. 5 illustrates a schematic illustration of an isometric view of the safety device 300 of FIG. 4A and FIG. 4B according to an embodiment of the present invention. The safety device 300 includes a drive motor 404, a magnetic coupling device 406, a housing 408, a shaft 410, a safety latch 412, a foot area 414, and a safety buffer 416.

As shown in FIG. 5 , the foot region 414 can be bent at an angle (e.g., approximately 90 degrees) from the remainder of the safety latch 412. According to some embodiments, a tilting member (not shown) can connect the safety latch 412 to the foot region 414 so that the foot region 414 is disposed below a parallel plane of the safety latch 412.

In some embodiments, the safety device 300 can be a rigid material, such as metal or ceramic. In some embodiments, the housing 408 of the safety device 300 can be cylindrical and extend through a portion of the zoom mask stage 200 for rigid alignment with the corner of the zoom mask. In some embodiments, the safety latch 412 can be configured to stabilize (e.g., detect) and reduce damage to the zoom mask during a collision. For example, the foot region 414 of the safety latch 412 can extend above the top surface of the zoom mask and can be configured to prevent the zoom mask from moving in a direction perpendicular to the surface of the top stage surface 202 (e.g., the Z direction).

6A, 6B, and 6C illustrate schematic diagrams of example magnetic coupling configurations for a safety device according to an embodiment of the present invention. Specifically, FIG. 6A illustrates a face-to-face magnetic coupling configuration 600, FIG. 6B illustrates a coaxial magnetic coupling configuration 610, and FIG. 6C illustrates an example of a magnetic coupling surface 620.

The face-to-face magnetic coupling configuration 600 of FIG. 6A is a face-to-face magnetic coupling mechanism, in which the surfaces of the driving component 406a and the driven component 406b are placed adjacent to each other with a material therebetween. The surfaces of the driving component 406a and the driven component 406b are lined with a plurality of permanent magnets that attract each other, resulting in a magnetic coupling device 406. In some embodiments, the surfaces of the driving component 406a and the driven component 406b may be separated by a material having a predetermined thickness between the two components (e.g., a distance of about 1.5 mm to 6 mm may separate the driving component 406a and the driven component 406b).

The coaxial magnetic coupling configuration 610 of FIG. 6B is a coaxial magnetic coupling mechanism in which the cylindrical ends of the driver component 406a and the driven component 406b are coaxially coupled to each other. The cylindrical ends of the driver component 406a and the driven component 406b can be separated by a material (e.g., an insulator) to provide a contactless magnetic coupling mechanism in a safety device. In some embodiments, the outer cylindrical end of the driver component 406a can be coaxially coupled with the inner cylindrical end of the driven component 406b. For example, the inner surface of the outer cylindrical end of the driver component 406a may be lined with permanent magnets that are attracted to oppositely polarized permanent magnets that are laid on the outer surface of the inner cylindrical end of the driven component 406b.

In other embodiments, the outer cylindrical end of the driven component 406b may be coaxially coupled to the inner cylindrical end of the driving component 406a. For example, the inner surface of the outer cylindrical end of the driven component 406b may be lined with permanent magnets that are attracted to oppositely polarized permanent magnets that are laid on the outer surface of the inner cylindrical end of the driving component 406a.

FIG. 6C further illustrates an example of a magnetic coupling surface 620. Magnetic coupling surface 620 may represent a surface of a driving component 406a and/or a surface of a driven component 406b in a face-to-face coupling mechanism (e.g., face-to-face magnetic coupling configuration 600). Coupling surface 620 may include a plurality of magnets 625 arranged in a circular manner on the surface of driving component 406a and/or driven component 406b. In some embodiments, the spacing between magnets 625 and the number of magnets 625 may be selected based on the resolution of the motion of the driving motor 404 and the coupling strength between the driving component 406a and the driven component 406b.

Although only two magnetic coupling configurations are shown in FIG. 6A to FIG. 6C , it should be understood that the magnetic coupling device 406 can utilize other embodiments of magnetic coupling mechanisms or configurations to couple the driving component 406a and the driven component 406b. By utilizing various magnetic coupling mechanisms (e.g., face-to-face coupling mechanisms, coaxial coupling mechanisms, or the like), the driven side of the safety device can move based on its connection with the driving side having a driving motor.

In addition, the contactless magnetic coupling device 406 can have advantages by providing a dual-stable actuation mechanism, where vibrations on the driving side 401 (where the drive motor 404 is located) are physically isolated from the driven side 402, so that the transmission of vibrations or disturbances to the chuck is greatly reduced. In addition, the spacing between the driving side 401 and the driven side 402 in the safety device provides a barrier or particle trap between the two sides that helps prevent particles from entering from the driving side 401. In some embodiments, because the couplings are magnetically connected, the present invention allows for some misalignment (e.g., axial and angular) between the couplings (e.g., between the driver assembly 406a and the driven assembly 406b) while maintaining a bi-stable actuation mechanism. In other words, when the driver side 401 is not actuated, the driven side 402 remains in place.

FIG. 7 illustrates a top view of a patterned device 208 and a security device 300 adjacent to a corner of the patterned device 208 according to an embodiment of the present invention. It should be noted that FIG. 7 is not drawn to scale and certain features are larger for clarity. Furthermore, the positioning of the security device 300 relative to the patterned device 208 is not intended to be limiting. The security device 300 may be located anywhere around the perimeter of the patterned device 208.

As shown in FIG7 , the safety latch 412 of the safety device 300 rotates between a first position shown on the left side and a second position shown on the right side. In the first position, the foot area 414 is aligned under the patterned device 208 so that the patterned device 208 contacts the foot area 414 if the patterned device 208 is disengaged from the chuck (not shown in FIG7 ) and falls in the Z direction. In the second position, the safety latch 412 has rotated away from the patterned device 208 so that no portion of the safety latch 412 is under the patterned device 208. According to one embodiment, the safety latch 412 will rotate into the first position when the patterned device 208 is coupled to the chuck. According to an embodiment, the safety latch 412 will rotate to the second position during loading or removal of the patterned device 208 from the chuck. The rotation angle θ of the safety latch 412 between the first position and the second position may be between 5 degrees and 20 degrees. Other rotation angles are also possible based on the length of the safety latch 412.

In some embodiments, the advantage of using a safety device having a dual-state motor (e.g., drive motor 404) and a magnetic coupling device to rotate the safety latch 412 is that the motor consumes power only during rotation and does not consume power when the safety latch 412 is stationary in the first position or the second position. For example, the motor is powered only when the safety latch 412 rotates from the first position to the second position (and vice versa), and lasts only for a short time (e.g., 0.5 seconds to 3 seconds). Therefore, the motor does not need to be turned on for a long time, and ultimately no active cooling is required.

In some embodiments, the safety device 300 with magnetic coupling may not rely on a rotational or compression spring to provide a force for maintaining the safety latch 412 in the first position. In addition, the safety device 300 with a drive motor and a magnetic coupling device may have a low mass compared to previous safety designs (e.g., safety devices using electromagnets).

Example Shape Memory Alloy (SMA) Mechanism for Security Devices

FIG8A and FIG8B illustrate an example diagram of a shape memory alloy (SMA) actuator mechanism for a security device (e.g., security device 300) according to an embodiment of the present invention. Specifically, FIG8A illustrates a front view of the actuator mechanism 800 in a first position (e.g., a closed position), and FIG8B illustrates a front view of the actuator mechanism 810 in a second position (e.g., an open position).

The actuator mechanisms 800 and 810 include a shape memory alloy 802, a pin joint 804, a spring 806, a safety latch 808, and a multiplying mask foot 809. The movement of the actuator mechanisms 800 and 810 in the safety device occurs by displacement of the safety latch 808 (e.g., a lever or seesaw mechanism) in the Z direction. Although only one shape memory alloy 802, pin joint 804, and spring 806 are shown in FIGS. 8A and 8B, the actuator mechanisms 800 and 810 may utilize any number of shape memory alloys 802, pin joints 804, and/or springs 806 in the safety device to increase the actuation force in the safety device.

In FIG. 8A , the actuator mechanism 800 is shown in a non-actuated, closed position when a reticle (e.g., reticle 208) is clamped to the surface of a chuck, such as during a reticle scan. A spring 806 can hold the actuator in the closed position until the actuator is actuated. For example, the spring 806 can be a tension spring. In some embodiments, the shape memory alloy 802 and the spring 806 can be pre-selected based on the actuation force required to actuate the device and the holding force required to hold the actuator in the closed position. Specifically, the seesaw mechanism can be used to convert the linear motion of the shape memory alloy 802 into a swing in the Z direction in the safety latch 808.

To rotate the safety latch 808 to the open position as shown by the actuator mechanism 810 in FIG. 8B , a current 811 may be applied to the shape memory alloy 802 to activate the shape memory alloy 802 (e.g., by heating) and cause the safety latch 808 to move (e.g., rotate). After releasing or removing the current 811, the spring 806 may compress and cause the safety latch 808 to return from the open position in FIG. 8B to the closed position in FIG. 8A . In some embodiments, the shape memory alloy 802 may be cooled to facilitate the shape memory alloy 802 to return to its original shape (e.g., closed position or open position).

In some embodiments, the safety latch 808 may have a length of about 15 mm and may rotate from a closed position to an open position by a predetermined rotation angle between about 5 degrees and about 20 degrees in response to activation of the shape memory alloy 802. In some embodiments, the safety latch 808 may rotate about 5 mm from the closed position to the K open position, or vice versa. The zoom shield foot 809 may be disposed at the distal end of the safety latch 808 at an angle (e.g., 90 degrees) to the remainder of the safety latch 808.

9A and 9B illustrate additional example diagrams of a shape memory alloy (SMA) actuator mechanism for a security device (e.g., security device 300) according to an embodiment of the present invention. Specifically, FIG. 9A illustrates a front view of the actuator mechanism 900 in a first position (e.g., a closed position), and FIG. 9B illustrates a top view of the actuator mechanism 910 in a second position (e.g., an open position).

The actuator mechanisms 900 and 910 use a rotational configuration where the shape memory alloy 902 and spring 906 are integrated into the drive motor 404 and coupled to a safety latch 908 having a multiplied mask leg 909. Although three shape memory alloys 902 and springs 906 are shown in Figures 9A and 9B, the actuator mechanisms 900 and 910 may utilize any number of shape memory alloys 902 and/or springs 906 in the security device in order to reduce or increase the actuation force in the security device. In some embodiments, spring 906 may be an expansion spring and/or a compression spring, and safety latch 908 in actuator mechanisms 900 and 910 may be displaceable in the X and Y directions as shown by the top views of FIGS. 9A and 9B .

For example, spring 906 may be a compression spring arranged in parallel with shape memory alloy 902 in actuator mechanisms 900 and 910. When current is applied to shape memory alloy 902, the shape memory alloy 902 may heat up and expand, causing safety latch 908 to rotate from the first position to the second position. Once the current is cut off, spring 906 may compress and promote the shape memory alloy 902 to shrink to its previous shape/configuration, causing safety latch 908 to rotate back from the second position to the first position.

In another example, the spring 906 can be an expansion spring arranged in parallel with the shape memory alloy 902 in the actuator mechanisms 900 and 910. The shape memory alloy 902 can resist the expansion of the spring 906 until current flows through the shape memory alloy 902. In some cases, once current has been applied to the shape memory alloy 902, the shape memory alloy 902 expands, and the spring 906 promotes the expansion of the shape memory alloy 902, causing the safety latch 908 to rotate from the first position to the second position. Once the current is cut off, the shape memory alloy 902 cools and contracts to its original position, while also causing the spring 906 to contract back to its original position. This contraction causes the safety latch 908 to rotate from the second position back to the first position.

In some embodiments, the actuator mechanisms 800, 810, 900, and/or 910 may be combined with the magnetic coupling device 406 shown in FIGS. 4A, 4B, and 5 to provide an enhanced security device. FIGS. 10A to 10D show examples of shape memory alloy actuators and security devices for multiplied mask security according to embodiments of the present invention. Specifically, FIG. 10A illustrates a schematic illustration of a top view of security device 1000, FIG. 10B illustrates a side view of security device 1010, and FIG. 10C illustrates an isometric view of security device 1020. FIG. 10D illustrates an isometric view of a shape memory alloy actuator and security device in a chuck 1030.

The safety device shown in FIGS. 10A to 10C includes a shape memory alloy 1002 arranged in parallel with a spring 1006 and coupled to a safety latch 1008 having a multiplied mask leg 1009. In some embodiments, the shape memory alloy 1002 and the spring 1006 may be packaged or integrated into a rotary drive motor 1004, which may be used to drive the safety latch to shift in the X and Y directions.

Example operation method

FIG. 11 is a flow chart of an exemplary method 1100 for operating a device for supporting patterning according to an embodiment of the present invention. Method 1100 may describe the operation of a security device 300 and its corresponding security latch 412, as discussed above with reference to FIGS. 2 to 10 . It should be understood that the operations shown in method 1100 are not exhaustive, and other operations may be performed before, after, or between any of the operations described. In various embodiments of the present invention, the operations of method 1100 may be performed in different orders and/or varied.

In operation 1102, a safety device is used to support a patterned device. The safety device may include an actuator having at least one shape memory alloy, a safety latch, and at least one spring coupled to the safety latch. The safety latch includes a foot portion at a distal end of the safety latch, wherein the foot portion is configured to serve as a contact point for the patterned device. In some embodiments, the safety device may be used in a rotational configuration. In other embodiments, the safety device may be used in a seesaw configuration.

In operation 1104, a current is applied to at least one shape memory alloy of the security device to activate the at least one shape memory alloy. In some embodiments, the activation of the at least one shape memory alloy may include expansion of the at least one shape memory alloy and expansion of at least one spring in the security device. In other embodiments, the activation of the at least one shape memory alloy may include compression of the at least one shape memory alloy and compression of at least one spring in the security device.

In operation 1106, in response to activating at least one shape memory alloy, a safety latch of the security device is actuated from a first position below the patterned device to a second position. In some embodiments, expansion of the shape memory alloy may cause the safety latch to rotate from an "open" position to a "closed" position, or vice versa. The safety latch includes a foot portion at a distal end of the safety latch, wherein the foot portion is configured to serve as a contact point for a zoom mask. It should be understood that any position of the safety latch may be considered an "open" position as long as the safety latch does not interfere with loading the zoom mask into the zoom mask chuck.

In operation 1108, current is removed from at least one shape memory alloy of the security device. In some embodiments, the current may be removed by cooling the shape memory alloy 802 or by shutting off a current source to the at least one shape memory alloy.

In operation 1110, in response to removing current from at least one shape memory alloy, a safety latch of the security device is actuated from a second position to a first position. In some cases, the shape memory alloy may contract to its original position, which causes the safety latch to rotate from a "closed" position to an "open" position, or vice versa.

The following terms may be used to further describe the embodiments:

1. A safety device for providing support for an object, comprising: a driving side, comprising a driving motor; and a driven side, comprising: a housing, comprising a rotating shaft extending along a length of the housing; and a safety latch, wherein the driven side is coupled to the driving motor at a first end of the rotating shaft via a non-contact magnetic coupling device, wherein the safety latch is coupled to a second end of the rotating shaft opposite to the first end of the rotating shaft, and wherein the driving motor is configured to rotate the safety latch in a radial direction on the driving side via the non-contact magnetic coupling device.

2. A safety device as in item 1, wherein: the non-contact magnetic coupling device comprises two components; and a plurality of permanent magnets are arranged on adjacent surfaces of the two components and provide an attractive force between the two components of the magnetic coupling device.

3. A safety device as in item 1, wherein the contactless magnetic coupling device comprises a face-to-face coupling mechanism.

4. A safety device as in item 1, wherein the non-contact magnetic coupling device comprises a coaxial coupling mechanism.

5. A safety device as in clause 1, wherein the safety latch is configured to rotate between a first position and a second position, the first position and the second position being separated by an angle between about 5 degrees and about 20 degrees.

6. A safety device as in clause 1, wherein the drive motor comprises a piezoelectric motor or a dual-state DC motor.

7. A safety device as in clause 1, wherein the safety latch comprises a foot portion at a distal end of the safety latch away from the rotation axis, the foot portion being configured to serve as a contact point for the object.

8. A lithography apparatus comprising: an illumination system configured to modulate a radiation beam; a support structure configured to support a patterning device capable of imparting a pattern to the radiation beam in a cross-section of the radiation beam to form a patterned radiation beam; a projection system configured to project the patterned radiation beam onto a target portion of a substrate; and one or more security devices coupled to the support structure, each of the one or more security devices comprising: a A driving side including a driving motor; and a driven side including: a housing including a rotating shaft extending along a length of the housing; and a safety latch, wherein the driven side is coupled to the driving motor via a contactless magnetic coupling device at a first end of the rotating shaft, wherein the safety latch is coupled to a second end of the rotating shaft opposite to the first end of the rotating shaft, and wherein the driving motor is configured to rotate the safety latch in a radial direction on the driving side via the contactless magnetic coupling device.

9. A lithography device as in item 8, wherein: the non-contact magnetic coupling device comprises two components; and a plurality of permanent magnets are arranged on adjacent surfaces of the two components and provide an attractive force between the two components of the magnetic coupling device.

10. A lithography device as in item 8, wherein the non-contact magnetic coupling device comprises a surface-to-surface coupling mechanism.

11. A lithography apparatus as in clause 8, wherein the non-contact magnetic coupling device comprises a coaxial coupling mechanism.

12. The lithography apparatus of clause 8, wherein the safety latch is configured to rotate between a first position and a second position, the first position and the second position being separated by an angle between about 5 degrees and about 20 degrees.

13. A lithography apparatus as in clause 8, wherein the drive motor comprises a piezoelectric motor or a dual-state DC motor.

14. A lithography apparatus as in clause 8, wherein the safety latch comprises a foot portion at a distal end of the safety latch away from the rotation axis, the foot portion being configured to serve as a contact point for the patterning device.

15. A method comprising: supporting a patterned device using a security device, the security device comprising an actuator having at least one shape memory alloy, a security latch and at least one spring coupled to the security latch, the security latch comprising a foot portion at a distal end of the security latch, the foot portion being configured to serve as a contact point of the patterned device; applying a current to at least one shape memory alloy of the security device to activate the at least one shape memory alloy; and actuating the security latch from a first position below the patterned device to a second position in response to the activation of the at least one shape memory alloy.

16. The method of clause 15, wherein the use comprises: using the at least one shape memory alloy and the at least one spring coupled to the safety latch in the actuator in a rotational configuration.

17. The method of clause 15, wherein the use comprises: using the at least one shape memory alloy in a seesaw configuration and at least one spring in the actuator coupled to the safety latch.

18. The method of clause 15, further comprising: removing current from the at least one shape memory alloy of the security device to actuate the security latch from the second position to the first position.

19. The method of clause 15, further comprising: Expanding the at least one spring in response to applying the current to the at least one shape memory alloy.

20. The method of clause 15, further comprising: compressing at least one spring in response to applying the current to the at least one shape memory alloy.

Final Conclusion

Although specific reference may be made herein to a "reduction mask," it should be understood that this is only one example of a patterned device and the embodiments described herein may be applicable to any type of patterned device. In addition, the embodiments described herein may be used to provide secure support for any object to ensure that a clamping failure does not cause the object to fall and damage itself or other equipment.

Although specific reference may be made herein to the use of lithography apparatus in IC manufacturing, it should be understood that the lithography apparatus described herein may have other applications, such as the manufacture of integrated optical systems, guide and detection patterns for magnetic resonance memory, flat panel displays, LCDs, thin film heads, etc. Those skilled in the art should understand that in the context of such alternative applications, any use of the terms "wafer" or "die" herein may be considered synonymous with the more general terms "substrate" or "target portion," respectively. The substrates mentioned herein may be processed before or after exposure in, for example, an automated photoresist coating and development system unit (a tool that typically applies a resist layer to a substrate and develops the exposed resist), a metrology unit, and/or an inspection unit. Where applicable, the disclosures herein may be applied to these and other substrate processing tools. Furthermore, a substrate may be processed more than once, for example, to produce a multi-layer IC, so that the term "substrate" as used herein may also refer to a substrate that already contains multiple processed layers.

Although the above may specifically refer to the use of embodiments of the invention in the context of optical lithography, it will be appreciated that the invention may be used in other applications, such as imprint lithography, and is not limited to optical lithography where the context permits. In imprint lithography, the topography in the patterned device defines the pattern produced on the substrate. The topography of the patterned device may be pressed into a layer of resist supplied to the substrate, where the resist is cured by applying electromagnetic radiation, heat, pressure, or a combination thereof. After the resist has cured, the patterned device is removed from the resist, leaving the pattern therein.

It should be understood that the terms and expressions used herein are for descriptive purposes rather than limiting purposes, so that the terms and expressions used in this specification should be interpreted by a person of ordinary knowledge in the relevant field in light of the teachings herein.

As used herein, the term "substrate" describes the material to which a layer of material is added. In some embodiments, the substrate itself may be patterned, and the material added on top of the substrate may also be patterned, or may remain unpatterned.

Embodiments of the present invention may be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the present invention may also be implemented as instructions stored on a machine-readable medium that may be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form that is readable by a machine (e.g., a computing device). For example, a machine-readable medium may include read-only memory (ROM); random access memory (RAM); disk storage media; optical storage media; flash memory devices; electrical, optical, acoustic, or other forms of propagated signals, and others. Additionally, firmware, software, routines, and/or instructions may be described herein as performing certain actions. However, it should be understood that such descriptions are for convenience only and that such actions are actually caused by a computing device, processor, controller or other device executing firmware, software, routines and/or instructions.

The following examples illustrate but do not limit embodiments of the present invention. Other suitable modifications and adjustments of the various conditions and parameters commonly encountered in the field that will be apparent to those skilled in the art are within the spirit and scope of the present invention.

Although specific reference may be made herein to the use of devices and/or systems according to the present invention in the manufacture of ICs, it should be expressly understood that such devices and/or systems have a variety of other possible applications. For example, they may be used in the manufacture of integrated optical systems, guide and detection patterns for magnetic memory, LCD panels, thin film heads, etc. Those skilled in the art will understand that in the context of such alternative applications, any use of the terms "mask", "wafer" or "die" herein should be considered to be replaced by the more general terms "mask", "substrate" and "target portion", respectively.

Although specific embodiments of the present invention have been described above, it should be understood that the present invention may be practiced in other ways than those described. This description is not intended to limit the present invention.

It should be understood that the [Implementation Method] section, rather than the [Contents of the Invention] and [Abstract of the Invention in Chinese] sections, is intended to be used to interpret the scope of the patent application. The [Contents of the Invention] and [Abstract of the Invention in Chinese] sections may describe one or more but not all exemplary embodiments of the invention as intended by the inventor, and therefore, are not intended to limit the scope of the invention and the attached patent application in any way.

The present invention has been described above by means of functional building blocks that illustrate the implementation of specific functions and their relationships. For ease of description, the boundaries of such functional building blocks have been arbitrarily defined herein. Alternative boundaries may be defined as long as the specified functions and relationships of such functions are properly performed.

The foregoing description of specific embodiments will fully disclose the general nature of the present invention so that others can easily modify and/or adjust these specific embodiments for various applications by applying knowledge within the skill of this technology without undue experimentation without departing from the general concept of the present invention. Therefore, based on the teachings and guidance presented herein, such adjustments and modifications are intended to be within the meaning and scope of equivalents of the disclosed embodiments.

Therefore, the breadth and scope of the present invention should not be limited by any of the above-mentioned exemplary embodiments, but should be defined solely according to the scope of the following patent applications and their equivalents.

200: Zoom mask stage

201: Buffer device

202: Top stage surface

208: Zoom mask

212: First encoder

214: Second encoder

300: Safety device

Claims (14)

A safety device for providing support for an object, comprising: a driving side including a driving motor; and a driven side including: a housing including a rotating shaft extending along a length of the housing; and a safety latch, wherein the driven side is coupled to the driving motor via a contactless magnetic coupling device at a first end of the rotating shaft, wherein the safety latch is coupled to a second end of the rotating shaft opposite the first end of the rotating shaft, and wherein the driving motor is configured to rotate the safety latch in a radial direction on the driving side via the contactless magnetic coupling device. A safety device as claimed in claim 1, wherein: The non-contact magnetic coupling device comprises two components; and A plurality of permanent magnets are arranged on adjacent surfaces of the two components and provide an attractive force between the two components of the magnetic coupling device. A safety device as claimed in claim 1, wherein the contactless magnetic coupling device includes a surface-to-surface coupling mechanism. A safety device as claimed in claim 1, wherein the contactless magnetic coupling device includes a coaxial coupling mechanism. A security device as in claim 1, wherein the security latch is configured to rotate between a first position and a second position, the first position and the second position being separated by an angle between approximately 5 degrees and approximately 20 degrees. A safety device as claimed in claim 1, wherein the drive motor comprises a piezoelectric motor or a dual-state DC motor. A safety device as claimed in claim 1, wherein the safety latch includes a foot portion at a distal end of the safety latch away from the rotation axis, the foot portion being configured to serve as a contact point for the object. A lithography apparatus comprises: an illumination system configured to modulate a radiation beam; a support structure configured to support a patterning device capable of imparting a pattern to the radiation beam in a cross-section of the radiation beam to form a patterned radiation beam; a projection system configured to project the patterned radiation beam onto a target portion of a substrate; and one or more security devices coupled to the support structure, each of the one or more security devices comprising: a driver a driving side including a drive motor; and a driven side including: a housing including a rotating shaft extending along a length of the housing; and a safety latch, wherein the driven side is coupled to the drive motor at a first end of the rotating shaft via a contactless magnetic coupling device, wherein the safety latch is coupled to a second end of the rotating shaft opposite the first end of the rotating shaft, and wherein the drive motor is configured to rotate the safety latch in a radial direction on the driving side via the contactless magnetic coupling device. A lithography device as claimed in claim 8, wherein: The non-contact magnetic coupling device comprises two components; and A plurality of permanent magnets are arranged on adjacent surfaces of the two components and provide an attractive force between the two components of the magnetic coupling device. A lithography apparatus as claimed in claim 8, wherein the non-contact magnetic coupling device comprises a surface-to-surface coupling mechanism. A lithography apparatus as claimed in claim 8, wherein the non-contact magnetic coupling device comprises a coaxial coupling mechanism. A lithography apparatus as in claim 8, wherein the safety latch is configured to rotate between a first position and a second position, the first position and the second position being separated by an angle between about 5 degrees and about 20 degrees. A lithography apparatus as claimed in claim 8, wherein the drive motor comprises a piezoelectric motor or a dual-state DC motor. A lithography apparatus as claimed in claim 8, wherein the safety latch includes a foot portion at a distal end of the safety latch away from the rotation axis, the foot portion being configured to serve as a contact point for the patterned device.