CN112969972A - Sensor array for real-time detection of reticle position and force - Google Patents

Abstract

A clamping apparatus configured to hold a reticle in a fixed plane on a reticle stage comprises: a fixture, a sensor, and a controller. The sensor is disposed on a front side of the clamp and is configured to detect a position of the reticle in a reticle exchange area during a reticle exchange process. The position of the reticle includes a vertical distance between a back side of the reticle and the front side of the fixture, and a relative inclination between the back side of the reticle and the front side of the fixture. The controller is coupled to the sensor and configured to control a position of the clamp based on the position of the reticle detected by the sensor.

Description

Sensor array for real-time detection of reticle position and force

Cross Reference to Related Applications

The present application claims priority from (1) U.S. provisional patent application No. 62/758,093 filed 2018, 11, 9 and (2) U.S. provisional patent application No. 62/801,888 filed 2019, 2, 6, both of which are incorporated herein by reference in their entirety.

Technical Field

The present disclosure relates to sensors, for example, positioning and force sensors for reticles in lithographic apparatus and systems.

Background

A lithographic apparatus is a machine that is configured to apply a desired pattern onto a substrate. Lithographic apparatus can be used, for example, in the manufacture of Integrated Circuits (ICs). A lithographic apparatus may, for example, project a pattern of a patterning device (e.g., mask, reticle) onto a layer of radiation-sensitive material (resist) disposed on a substrate.

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

During a reticle exchange process, reticle handoffs or transfers from a reticle handler to a gripper of a reticle stage include unknown reticle positional offsets and reticle tilt angle offsets. Tilt angles or excessive misalignment between the chuck and the reticle may be a source of particle generation and may damage the reticle or the chuck over time. Regardless of the calibration, there are still variations due to reticle mechanical and positioning tolerances, which may result in high corner effects and unpredictable first contact points on the chuck and reticle. There is a need to reduce damage to reticles and clamps in a reliable, uniform and efficient manner.

Disclosure of Invention

In some embodiments, a clamping device includes a clamp, a sensor, and a controller. In some embodiments, the clamping device is configured to hold the reticle in a fixed plane on the reticle stage. In some embodiments, the sensor is disposed on a front side of the clamp. In some embodiments, the sensor is configured to detect a position of a reticle in a reticle exchange area during a reticle exchange process. In some embodiments, the position of the reticle includes a vertical distance between a backside of the reticle and the front side of the chuck, and a relative tilt angle between the backside of the reticle and the front side of the chuck. In some embodiments, the controller is coupled to the sensor and configured to control a position of the clamp based on the position of the reticle detected by the sensor. In some embodiments, the sensor is a sensor array.

In some embodiments, the controller is configured to correct a vertical distance offset and a relative tilt angle offset between the backside of the reticle and the front side of the chuck in real time. In some embodiments, the controller is configured to control the reticle stage to allow compliant movement of the clamp until the front side of the clamp and the back side of the reticle are in contact and coplanar. In some embodiments, the controller is configured to reduce contact forces and minimize particle generation between the reticle and the clamp. In some embodiments, the controller is configured to move a reticle stage at a first speed until the position of the reticle is detected by the sensor, and to move the reticle stage at a second speed, the first speed being greater than the second speed.

In some embodiments, the sensor is capacitive and comprises a planar electrode. In some embodiments, the sensor is optical and includes a light source and a light detector. In some embodiments, the light source is directed at the backside of the reticle at an acute angle relative to the front side of the jig. In some embodiments, the sensor is pressurized and comprises a barometer. In some embodiments, the sensor comprises a plurality of sensor arrays.

In some embodiments, a clamping device includes a clamp, a sensor, and a controller.

In some embodiments, the clamping device is configured to hold the reticle in a fixed plane on the reticle stage. In some embodiments, a sensor is disposed on a front side of the clamp. In some embodiments, the sensor is configured to detect a force of the reticle in a reticle exchange area during a reticle exchange process. In some embodiments, the force of the reticle comprises a stress or strain from a backside of the reticle or the front side of the chuck. In some embodiments, the controller is coupled to the sensor and configured to control a position of the clamp based on the force of the reticle detected by the sensor. In some embodiments, the sensor is a sensor array.

In some embodiments, the controller is configured to correct in real time stress or strain from the backside of the reticle or the front side of the chuck. In some embodiments, the controller is configured to control a reticle stage to allow compliant movement of the clamp until the front side of the clamp and the back side of the reticle are in contact and coplanar.

In some embodiments, the sensor is resistive and comprises a planar strain gauge. In some embodiments, the sensor is resistive and includes a lithographically patterned resistor. In some embodiments, the lithographically patterned resistor is configured to change resistance in proportion to an applied pressure.

In some embodiments, a board apparatus includes a board, a sensor, and a controller. In some embodiments, the plate apparatus is configured to adjust the reticle to a fixed plane on a chuck on a reticle stage in the lithographic apparatus. In some embodiments, the plate comprises a reticle exchange port. In some embodiments, the sensor is disposed in the reticle exchange port. In some embodiments, the sensor is configured to detect a position of a reticle in a reticle exchange area during a reticle exchange process. In some embodiments, the position of the reticle includes a vertical distance between a backside of the reticle and a fixed plane of the sensor and a relative tilt angle between the backside of the reticle and the fixed plane of the sensor. In some embodiments, the controller is coupled to the sensor and configured to control a position of a clamp based on the position of the reticle detected by the sensor. In some embodiments, the sensor is a sensor array.

In some embodiments, the controller is configured to correct a vertical distance offset and a relative tilt angle offset between the backside of the reticle and a front side of the chuck in real time. In some embodiments, the controller is configured to control a reticle stage to allow compliant movement of the clamp until a front side of the clamp and the back side of the reticle are in contact and coplanar.

In some embodiments, the sensor is optical and includes a light source and a light detector. In some embodiments, the light source is a projected light pattern and is configured to allow structured light stereo detection by the sensor. In some embodiments, the sensor is optical and comprises a confocal sensor configured to be time synchronized.

In some embodiments, a board apparatus includes a board, a sensor, and a controller. In some embodiments, the plate apparatus is configured to calibrate the reticle to a fixed plane on a fixture on a reticle stage in the lithographic apparatus. In some embodiments, the plate comprises a reticle exchange port. In some embodiments, the sensor is disposed on a backside of the plate and distal from the reticle exchange port. In some embodiments, the sensor is configured to calibrate a position of a reticle in a reticle exchange area based on a fixed plane of the sensor during a reticle exchange process. In some embodiments, the position of the reticle includes a vertical distance between a backside of the reticle and the fixed plane of the sensor and a relative tilt angle between the backside of the reticle and the fixed plane of the sensor. In some embodiments, the controller is coupled to the sensor and configured to control a position of the clamp based on the position of the reticle detected by the sensor. In some embodiments, the sensor is a sensor array.

In some embodiments, the controller is configured to correct a vertical distance offset and a relative tilt angle offset between the backside of the reticle and a front side of the clamp based on a vertical distance offset and a relative tilt angle offset between the backside of the reticle and the fixed plane of the sensor. In some embodiments, the sensor is configured to measure the backside of the reticle synchronously. In some embodiments, the sensor is capacitive and comprises a planar electrode. In some embodiments, the sensor array is optical and comprises one or more confocal sensors.

In some embodiments, a method includes detecting, with a sensor, a position of a reticle on a reticle stage, the reticle stage including a clamp for the reticle. In some embodiments, the position comprises a vertical distance between a backside of the reticle and a front side of the clamp and a relative tilt angle between the backside of the reticle and the front side of the clamp. In some embodiments, the method further comprises calculating a vertical distance offset and a relative tilt angle offset between the backside of the reticle and the front side of the clamp based on the position of the reticle detected by the sensor. In some embodiments, the method further comprises adjusting the clamp or the reticle to reduce the vertical distance offset and the relative tilt angle offset until the backside of the reticle and the front side of the clamp are in contact and coplanar. In some embodiments, the method is used to reduce contact forces and minimize particle generation between a chuck on a reticle stage and a reticle.

In some embodiments, the detecting, calculating, and adjusting are performed in real-time. In some embodiments, the method further comprises moving the reticle stage at a first speed until the position of the reticle is detected by the sensor, and moving the reticle stage at a second speed. In some embodiments, the first speed is greater than the second speed.

In some embodiments, an in-vacuum robotic device includes a base plate, a sensor, and a controller. In some embodiments, the bottom plate includes a first through hole. In some embodiments, the sensor is disposed below the floor. In some embodiments, the sensor is configured to detect a position of a reticle in a reticle exchange area through the first through-hole of the base plate during a reticle exchange process. In some embodiments, the position of the reticle includes a vertical distance between a front side of the reticle and a fixed plane of the sensor and a relative tilt angle between the front side of the reticle and the fixed plane of the sensor. In some embodiments, the controller is coupled to the sensor and configured to control a position of a clamp based on the position of the reticle detected by the sensor.

In some embodiments, the controller is configured to correct a vertical distance offset and a relative tilt angle offset between the front side of the reticle and a front side of the chuck in real time. In some embodiments, the controller is configured to control a reticle stage to allow compliant movement of the clamp until a front side of the clamp and a back side of the reticle are in contact and coplanar.

In some embodiments, the sensor is optical and comprises a confocal sensor configured to be time synchronized. In some embodiments, the sensors are acoustic and include ultrasonic sensors configured to be time synchronized. In some embodiments, the sensor is optical and includes a high resolution optical sensor for cadastral mapping, remote driving assistance, or reverse garage assistance.

In some embodiments, the sensor is optical and includes a light source and a light detector. In some embodiments, the light source is focused through the first through hole of the base plate and onto the front side of the reticle, and is configured to allow scattered light detection by the sensor. In some embodiments, the light source is an infrared light source. In some embodiments, the sensor further comprises one or more beam shaping optics.

In some embodiments, the in-vacuum robotic device further comprises a second through-hole in the base plate and a second sensor disposed below the base plate. In some embodiments, the second sensor is configured to detect a second position of the reticle in the reticle exchange area through the second aperture of the base plate during the reticle exchange process. In some embodiments, the second position of the reticle includes a vertical distance between the front side of the reticle and a fixed plane of the sensor and a relative tilt angle between the front side of the reticle and the fixed plane of the sensor. In some embodiments, the controller is coupled to the second sensor and configured to control a position of the clamp based on the second position of the reticle detected by the second sensor. In some embodiments, the controller is configured to correct a vertical distance offset and a relative tilt angle offset between the front side of the reticle and a front side of the clamp in real time based on a comparison between the position of the reticle detected by the sensor and the second position of the reticle detected by the second sensor.

Further features and advantages of the invention, as well as the structure and operation of various embodiments of the 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. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein.

Drawings

The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention. Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which:

FIG. 1 is a schematic illustration of a lithographic apparatus according to an example embodiment;

FIG. 2 is a perspective schematic illustration of a reticle stage according to an exemplary embodiment;

FIG. 3 is a top plan view of the reticle stage of FIG. 2;

FIG. 4 is a perspective schematic illustration of a reticle exchange tool according to an example embodiment;

FIG. 5 is a partial cross-sectional view of the reticle exchange tool of FIG. 4;

fig. 6A is a partial schematic illustration of a reticle exchange tool in a proximity configuration according to an example embodiment;

fig. 6B is a partial schematic illustration of a reticle exchange tool in a first contact configuration in accordance with an example embodiment;

fig. 6C is a partial schematic illustration of a reticle exchange tool in a full contact configuration in accordance with an example embodiment;

FIG. 7 is a top schematic illustration of a clamp according to an exemplary embodiment;

FIG. 8 is a top schematic illustration of a clamp according to an exemplary embodiment;

FIG. 9 is a top schematic illustration of a clamp according to an exemplary embodiment;

FIG. 10 is a top schematic illustration of a clamp according to an exemplary embodiment;

FIG. 11 is a top schematic illustration of a clamp according to an exemplary embodiment;

FIG. 12 is a top schematic illustration of a clamp according to an exemplary embodiment;

FIG. 13 is a perspective schematic illustration of a reticle exchange tool according to an example embodiment;

FIG. 14 is a partial cross-sectional view of the reticle exchange tool of FIG. 13;

FIG. 15 is a bottom schematic illustration of a plate in a reticle exchange configuration according to an example embodiment;

FIG. 16 is a bottom schematic illustration of a plate in a calibration configuration according to an exemplary embodiment;

FIG. 17 is a partial cross-sectional schematic illustration of a reticle exchange tool according to an example embodiment; and

fig. 18 is an enlarged partial cross-sectional view of the reticle exchange device of fig. 17.

The features and advantages of the present invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. In addition, in general, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. Unless otherwise indicated, the drawings provided throughout this disclosure should not be construed as being to scale.

Detailed Description

This specification discloses one or more embodiments that incorporate the features of this invention. The disclosed embodiments are merely illustrative of the invention. The scope of the invention is not limited to the disclosed embodiments. The invention is defined by the claims appended to this specification.

References in the described embodiments and this specification to "one embodiment," "an example embodiment," etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

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

The term "about" as used herein indicates a value of a given amount that may vary based on the particular technique. The term "about" can indicate a value of a given quantity, e.g., within 10% to 30% of the stated value (e.g., ± 10%, ± 20% or ± 30% of the stated value), based on the particular technique.

Embodiments of the present disclosure may be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the disclosure may also be implemented as instructions stored on a machine-readable medium, which 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 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); a magnetic disk storage medium; an optical storage medium; a flash memory device; electrical, optical, acoustical or other form of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.), and others. Further, firmware, software, routines, and/or instructions may be described herein as performing certain actions. However, it should be understood that such descriptions are merely for convenience and that such actions in fact result from computing devices, processors, controllers, or other devices executing the firmware, software, routines, instructions, etc., and that doing so may cause actuators or other devices to interact with the physical world.

However, before describing such embodiments in more detail, it is instructive to provide an example environment in which embodiments of the present disclosure may be implemented.

Exemplary lithography System

Fig. 1 shows a lithographic system comprising a radiation source SO and a lithographic apparatus LA. The radiation source SO is configured to generate an EUV radiation beam B and to supply the EUV radiation beam B to the lithographic apparatus LA. The lithographic apparatus LA comprises an illumination system IL, a support structure MT configured to support a patterning device MA (e.g. a mask), a projection system PS, and a substrate table WT configured to support a substrate W.

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

After being so conditioned, the EUV radiation beam B interacts with the patterning device MA. Due to this interaction, a patterned beam B' of EUV radiation is produced. 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 configured to project the patterned beam B' of EUV radiation 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', thus forming an image having smaller features than corresponding features on the patterning device MA. For example, a reduction factor of 4 or 8 may be applied. Although the projection system PS is illustrated as having only two mirrors 13, 14 in fig. 1, the projection system PS may comprise a different number of mirrors (e.g. six or eight mirrors).

The substrate W may include a previously formed pattern. In such cases, the lithographic apparatus LA aligns an image formed by the patterned EUV radiation beam B' with a pattern previously formed on the substrate W.

A relative vacuum, i.e. a small amount of gas (e.g. hydrogen) at a pressure substantially 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 producing EUV radiation.

Exemplary reticle stage

Fig. 2 and 3 show schematic illustrations of an exemplary reticle stage 200, according to some embodiments of the present disclosure. Reticle stage 200 may include a top stage surface 202, a bottom stage surface 204, side stage surfaces 206, and a clamp 300. In some embodiments, reticle stage 200 with clamp 300 may be implemented in a lithographic apparatus LA. For example, the reticle stage 200 may be a support structure MT in a lithographic apparatus LA. In some embodiments, the fixture 300 may be positioned on the top platform surface 202. For example, as shown in fig. 2, the clamp 300 may be positioned at the center of the top platform surface 202 with the clamp front side 302 facing vertically away from the top platform surface 202.

In some lithographic apparatus (e.g., lithographic apparatus LA), reticle stage 200 with clamp 300 may be used to hold and position reticle 408 for scanning or patterning operations. In one example, the reticle stage 200 may require a high power drive, a massive weight, and a heavy frame to support the reticle stage. In one example, the reticle stage 200 may have a large inertia and may weigh more than 500kg to push and position a reticle 408 weighing about 0.5 kg. To achieve the reciprocating motion of the reticle 408 typically found in lithographic scanning or patterning operations, acceleration and deceleration forces may be provided by linear motors driving the reticle stage 200.

In some embodiments, as shown in fig. 2 and 3, reticle stage 200 may include first encoder 212 and second encoder 214 for positioning operations. For example, the first encoder 212 and the second encoder 214 may be interferometers. First encoder 212 may be attached along a first direction (e.g., a lateral direction (i.e., the X direction)) of reticle stage 200. And a second encoder 214 may be attached along a second direction (e.g., a longitudinal direction (i.e., Y-direction)) of the reticle stage 200. In some embodiments, as shown in fig. 2 and 3, the first encoder 212 may be orthogonal to the second encoder 214.

As shown in fig. 2 and 3, reticle stage 200 may include a clamp 300. The fixture 300 is configured to hold the reticle 408 in a fixed plane on the reticle stage 200. The fixture 300 includes a fixture front side 302 and may be disposed on the top platform surface 202. In some embodiments, the gripper 300 may use mechanical, vacuum, electrostatic or other suitable gripping techniques to hold and secure the object. In some embodiments, the chuck 300 may be an electrostatic chuck, which may be configured to electrostatically chuck (i.e., hold) an object, such as reticle 408, in a vacuum environment. Due to the requirement for EUV to be performed in a vacuum environment, a vacuum chuck cannot be used to clamp the mask or reticle, and instead an electrostatic chuck may be used. For example, the fixture 300 may include electrodes, a resistive layer on the electrodes, a dielectric layer on the resistive layer, and protrusions protruding from the dielectric layer. In use, a voltage may be applied to the fixture 300, for example, several kV. And a current may flow through the resistive layer such that the voltage at the upper surface of the resistive layer will be approximately the same as the voltage of the electrodes and generate an electric field. In addition, coulombic forces, i.e., the attractive forces between charged particles of opposite charge polarity, will attract the object to the fixture 300 and hold the object in place. In some embodiments, the clip 300 may be a rigid material, such as a metal, dielectric, ceramic, or a combination thereof.

Exemplary reticle exchange device

Fig. 4-6 show schematic illustrations of an exemplary reticle exchange tool 100, according to some embodiments of the present disclosure. Reticle exchange tool 100 may be configured to minimize reticle exchange time, particle generation, and contact forces or stresses from jig 300 and/or reticle 408 to reduce damage to jig 300 and reticle 408 and increase overall throughput during reticle exchange (e.g., in lithography tool LA).

As shown in fig. 4 and 5, reticle exchange tool 100 may include a reticle stage 200, a clamp 300, and an in-vacuum robot 400. The in-vacuum robot 400 may include a reticle handler 402.

In some embodiments, the reticle handler 402 may be a Rapid Exchange Device (RED) configured to rotate efficiently and minimize reticle exchange time. For example, reticle handler 402 may save time by moving multiple reticles from one location to another location substantially simultaneously rather than sequentially.

In some embodiments, as shown in fig. 4, the reticle transport 402 may include one or more reticle transport arms 404. The reticle handler arm 404 may include a reticle base plate 406. Reticle base 406 may be configured to hold an object, such as reticle 408.

In some embodiments, reticle base plate 406 may be an extreme ultraviolet (EIP) chamber for reticles. In some embodiments, reticle base plate 406 includes a reticle base plate front side 407 and reticle 408 includes a reticle back side 409.

In some embodiments, as shown in fig. 4 and 5, reticle base plate 406 may hold reticle 408 such that reticle base plate front side 407 and reticle back side 409 face top stage surface 202 and chuck front side 302, respectively. For example, reticle base plate front side 407 and reticle back side 409 may face perpendicularly away from top stage surface 202 and chuck front side 302.

As shown in fig. 5, reticle exchange tool 100 may include a reticle exchange area 410, which is a cross-sectional area between clamp 300, reticle 408, reticle base plate 406, and reticle handler arm 404 during a reticle exchange process.

In some embodiments, as shown in fig. 4, the reticle transport arm 404 may be symmetrically arranged about the reticle transport 402. For example, the reticle handler arms 404 may be spaced about 90 degrees, 120 degrees, or 180 degrees apart from each other. In some embodiments, the reticle transport arm 404 may be asymmetrically arranged with respect to the reticle transport 402. For example, two reticle handler arms 404 may be spaced apart from each other by about 135 degrees, while the other two reticle handler arms 404 may be spaced apart from each other by about 90 degrees.

In one example, during a reticle exchange process, a reticle handler arm 404 of a reticle handler 402 positions a reticle 408 on a reticle base plate 406 in a reticle exchange area 410 towards the reticle 300. As described above, reticle handoff or transfer from reticle handler 402 to gripper 300 includes unknown reticle positional offsets including reticle vertical distance offset (i.e., Z direction offset) and reticle tilt angle offset (i.e., R)_XOffset and R_YOffset). Tilt angles or excessive misalignment between the reticle 408 and the chuck 300 may be a source of particle generation and may damage the reticle 408 or the chuck 300 over time. The reticle backside 409 and the jig front side 302 need to be in optimal coplanar alignment for final handover. Regardless of the calibration, there are still variations due to reticle mechanical and positioning tolerances, which may lead to high corner effects and unpredictable first contact points between the fixture 300 and the reticle 408.

In one example, the reticle exchange process may involve lowering the reticle stage 200 with the gripper 300 as close as possible to the reticle 408, starting away from the reticle handler 402 until the gripper 300 contacts the reticle 408 to account for all possible offsets and/or tilt angles. During the reticle exchange process, the reticle stage 200 with the clamp 300 may be adjusted in a multi-stage movement.

As shown in fig. 6A-6C, reticle exchange tool 100 may include a clamp 300, a reticle 408, and a reticle base plate 406. Multiple stage movements may occur in four phases: (1) approaching; (2) a first contact; (3) fully contacting; and (4) applying a voltage to the fixture.

First, as shown in fig. 6A, reticle exchange tool 100 may assume an access configuration 20, and clamp 300 may be adjusted in a substantially vertical direction (i.e., Z-direction) toward reticle backside 409. In the proximity configuration 20, the clamp 300 is closed (i.e., no voltage applied) and the reticle transport 402 disables the vertical direction (i.e., Z direction) and tilt angle (i.e., R) of the reticle transport arm 404 in the reticle exchange area 410_XAnd R_YRotating around the X direction and rotating around the Y direction, respectively). Motor (i.e., Z, R)_XAnd R_Y) Braking, and rotation about the Z direction (i.e., R)_Z) And (5) starting.

Second, as shown in fig. 6B, reticle exchange tool 100 may assume first contact configuration 30, and clamp 300 may be adjusted in a substantially vertical direction (i.e., Z-direction) toward reticle backside 409 until clamp 300 is in contact with reticle backside 409. In the first contact configuration 30, the clamp 300 is closed and the clamp 300 is in contact with the reticle backside 409, e.g., contacts a corner portion of the reticle 408, and then rotated or tilted about the contact (i.e., R)_XAnd R_Y)。

Third, as shown in fig. 6C, reticle exchange tool 100 may assume a full contact configuration 40, and clamp 300 may rotate about the contact (i.e., R)_XAnd R_Y) Adjusted towards the reticle back side 409 until the clamp 300 is in full contact with the reticle back side 409. In the full contact configuration 40, the clamp 300 is closed and the clamp 300 is in full contact with the reticle backside 409, e.g. all four corners of the reticle 408 and with the maskThe stencil backside 409 is coplanar.

In some embodiments, in the full contact configuration 40, the clamp 300 is in contact with all four corners of the reticle 408 and continues to move in a substantially vertical direction (i.e., the Z-direction) until a mechanical force of at least 5N is achieved.

Fourth, with the chuck front side 302 and the reticle back side 409 aligned and coplanar, the chuck 300 is opened (i.e., a voltage is applied to the chuck 300) and the reticle 408 is held in a fixed plane on the chuck 300.

In some embodiments, as shown in fig. 5, reticle exchange tool 100 may include a clamp controller 360. The clamp controller 360 may be coupled to the clamp 300 and may be configured to control a position of the clamp 300. For example, the clamp controller 360 may be configured to control the reticle stage 200 to allow compliant movement of the clamp 300. In some embodiments, the clamp controller 360 may be coupled to servo motors or servo actuators (i.e., X-direction, Y-direction, Z-direction, R-direction) of the reticle stage 200 and/or the clamp 300_X、R_Y、R_Z). For example, the chuck controller 360 may control translation of and about the X, Y, and Z axes (i.e., X, Y, Z directions) of the reticle stage 200 with the chuck 300 (i.e., X, Y, Z directions)_X、R_Y、R_Z) Wherein the x-axis, y-axis, and z-axis are orthogonal coordinates.

Exemplary Fixture for real-time reticle position detection

Fig. 7-10 show schematic illustrations of an example clamp 300 of an example reticle exchange tool 100, according to some embodiments of the present disclosure. Reticle exchange tool 100 may include a clamp 300, sensor arrays 310, 320, 330, and a clamp controller 360.

The sensor arrays 310, 320, 330 may be configured to detect a position of a reticle 408 in a reticle exchange area 410 during a reticle exchange process. For example, the reticle position may include a vertical distance between the reticle backside 409 and the chuck front side 302 (i.e., Z-direction) and a relative inclination angle between the reticle backside 409 and the chuck front side 302 (i.e., R)_XAnd R_Y)。

The sensor arrays 310, 320, 330 may be mounted on the fixture 300 or on the reticle stage 200. For example, the sensor arrays 310, 320, 330 may be disposed on the fixture front side 302. The sensor arrays 310, 320, 330 may be configured to detect reticle position (i.e., Z-direction, R)_X、R_Y)。

The clamp controller 360 may be coupled to the sensor arrays 310, 320, 330 and may be configured to be based on the reticle position (i.e., Z-direction, R-direction) detected by the sensor arrays 310, 320, 330_X、R_Y) To calculate and control the position of the fixture 300.

In some embodiments, the clamp controller 360 may be disposed on or in the clamp 300. In some embodiments, the clamp controller 360 may be disposed on the reticle stage 200 and may be coupled to the clamp 300. For example, the clamp controller 360 may be electrically or wirelessly (e.g., radio frequency) coupled to the clamp 300.

In some embodiments, the chuck controller 360 may be configured to correct vertical distance offset (i.e., Z-direction offset) and relative tilt angle offset (i.e., R-direction offset) between the reticle backside 409 and the chuck front side 302 in real time_XOffset and R_YOffset). For example, reticle position data (i.e., Z-direction, R) detected by the sensor arrays 310, 320, 330_X、R_Y) Can be determined by the chuck controller 360 and chuck position data (i.e., Z-direction, R)_X、R_Y) In contrast, to calculate the position offset (i.e., Z-direction offset, R)_XOffset, R_YOffset), the position offset may be reduced for each detection period (e.g., 1.0 ms).

In some embodiments, the chuck controller 360 may be configured to control the reticle stage 200 and/or the chuck 300 to allow compliant movement of the chuck 300 until the chuck front side 302 and the reticle back side 409 are fully in contact and coplanar, and/or to reduce contact forces and minimize particle generation between the reticle 408 and the chuck 300. For example, the fixture controller 360 may adjust by detecting a period (e.g., 1.0ms) for each sensor array 310, 320, 330Position of the gripper 300 (i.e., Z-direction, R)_X、R_Y) To calculate and reduce the positional offset (i.e., Z-direction offset, R) between reticle backside 409 and chuck front side 302_XOffset, R_YOffset).

In some embodiments, the gripper controller 360 may be configured to move the reticle stage 200 at a first speed until the sensor arrays 310, 320, 330 detect the reticle position (i.e., Z-direction, R-direction)_X、R_Y) To the reticle stage 200, and then moving the reticle stage 200 at a second speed that is less than the first speed. For example, during the approach configuration 20, the reticle stage 200 with the clamp 300 may be moved substantially in the vertical direction (i.e., Z-direction) at a first speed (e.g., 1.0m/s) until the sensor array 310, 320, 330 detects a threshold (e.g., predetermined) signal (i.e., Z-direction) of the reticle backside 409, at which time the clamp controller 360 controls and moves the reticle stage 200 at a second speed (e.g., 0.1 mm/s).

In some embodiments, reticle backside 409 damage may be mitigated by reducing the speed or velocity of reticle stage 200 and/or chuck 300 during the first contact (i.e., first contact configuration 30). In some embodiments, the lifetime of reticle backside 409 may be increased by alternating the areas on reticle backside 409 that are first contacted (i.e., during first contact configuration 30). In some embodiments, a partially damaged reticle 408 or fixture 300 may be safely used by changing the load zone or load conditions.

As shown in fig. 7, the fixture 300 may include a sensor array 310. The sensor array 310 may be capacitive. The sensor array 310 may include one or more planar electrodes 312, 314, 316, 318. In some embodiments, the sensor array 310 may be disposed on the front side 302 of the fixture. In some embodiments, the sensor array 310 may be disposed in the fixture 300. In some embodiments, the sensor array 310 may be disposed between the fixture 300 and the reticle stage 200. In some embodiments, the planar electrodes 312, 314, 316, 318 may be symmetrically arranged. For example, as shown in FIG. 7, the planar electrodes 312, 314, 316, 318 may beAre spaced apart by about 90 degrees. In some embodiments, the sensor array 310 may be arranged to improve offset (i.e., R) to the reticle backside 409_XAnd R_Y) The sensitivity of (2). For example, the sensor array 310 may include a plurality of electrodes disposed around the periphery or edge of the front side 302 of the fixture.

As shown in fig. 8, the fixture 300 may include a sensor array 320. The sensor array 320 may be optical. Sensor array 320 may include light sources 322 and light detectors 324. For example, the light source 322 may be a laser or a Light Emitting Diode (LED), and the light detector 324 may be a photodiode, such as a quadrant Avalanche Photodiode (APD). The light detector 324 may include a first detector 325, a second detector 326, a third detector 327, and a fourth detector 328.

In some embodiments, the light source 322 may be directed toward the reticle backside 409 and the light reflectivity of the light source 322 off the reticle backside 409 may be detected by the light detector 324 to determine the reticle position (i.e., Z-direction, R) based on the location of the light reflection on the light detector 324_X、R_Y). For example, the light source 322 may be directed toward the reticle backside 409, e.g., at an acute angle (e.g., 45 degrees) with respect to the chuck front side 302. In some embodiments, the sensor array 320 may be disposed on the front side 302 of the fixture. In some embodiments, the sensor array 320 may be disposed in the fixture 300 or recessed into the fixture 300. In some embodiments, the light source 322 and the light detector 324 may be symmetrically arranged. For example, as shown in fig. 8, both the light source 322 and the light detector 324 may be arranged along a diagonal of the front side 302 of the jig, e.g., with the light source 322 in the lower left quadrant and the light detector 324 in the upper right quadrant.

As shown in fig. 9, the fixture 300 may include a sensor array 330. The sensor array 330 may be pressurized. The sensor array 330 may include one or more pressure gauges 332, 334, 336, 338. In some embodiments, the sensor array 330 may be disposed on the fixture front side 302. In some embodiments, the sensor array 330 may be disposed in the fixture 300 or recessed into the fixture 300. In some embodiments, as shown in fig. 9, two or more pressure gauges 332, 334, 336, 338 may be symmetrically arranged. For example, four pressure gauges 332, 334, 336, 338 may be spaced about 90 degrees apart, or three pressure gauges 332, 334, 336 may be spaced about 120 degrees apart.

In some embodiments, one or more pressure gauges 332, 334, 336, 338 may be directed at the reticle backside 409, and the pressure difference from the reticle backside 409 may be detected by the corresponding one or more pressure gauges 332, 334, 336, 338 to determine the reticle position (i.e., Z-direction, R-direction) based on the pressure difference_X、R_Y). For example, the pressure gauges 332, 334, 336, 338 may be barometer nozzles directed perpendicularly to the reticle backside 409 at four locations on the chuck front side 302. For example, the pressure gauges 332, 334, 336 may be barometer nozzles directed perpendicularly to the reticle backside 409 at three symmetrical locations on the front side 302 of the jig.

As shown in fig. 10, the fixture 300 may include sensor arrays 310, 320, 330. For reticle backside 409 position (i.e., Z-direction, R)_X、R_Y) For better accuracy and detection, the fixture 300 may include multiple sensor arrays 310, 320, 330. In some embodiments, the fixture controller 360 may receive and analyze multiple signals from multiple sensor arrays 310, 320, 330 in real time (e.g., 1.0 ms).

Exemplary Fixture for real-time reticle force detection

Fig. 11 and 12 show schematic illustrations of an example clamp 300 of an example reticle exchange tool 100, according to some embodiments of the present disclosure. Reticle exchange tool 100 may include a clamp 300, sensor arrays 340, 350, and a clamp controller 360. The sensor arrays 340, 350 may be configured to detect forces of the reticle 408 in the reticle exchange region 410 during a reticle exchange process, e.g., reticle forces may include stress (σ) or strain (ε) from the reticle backside 409 or the clamp front side 302. The sensor arrays 340, 350 may be disposed on the fixture 300 or on the reticle stage 200. For example, the sensor arrays 340, 350 may be disposed on the fixture front side 302. The sensor arrays 340, 350 may be configured to detect reticle forces (i.e., σ X, σ Y, σ Z, ε X, ε Y, ε Z). The clamp controller 360 may be coupled to the sensor arrays 340, 350 and may be configured to calculate and control the position of the clamp 300 based on the reticle forces (i.e., σ X, σ Y, σ Z, ε X, ε Y, ε Z) detected by the sensor arrays 340, 350.

In some embodiments, the clamp controller 360 may be disposed on or in the clamp 300. In some embodiments, a clamp controller 360 may be disposed on the reticle stage 200 and may be coupled to the clamp 300. For example, the clamp controller 360 may be electrically or wirelessly (e.g., radio frequency) coupled to the clamp 300. In some embodiments, the chuck controller 360 may be configured to correct for stress (i.e., σ X, σ Y, σ Z) or strain (i.e., ε X, ε Y, ε Z) from the reticle backside 409 or the chuck front side 302 in real time. For example, reticle force data (i.e., σ X, σ Y, σ Z, ε X, ε Y, ε Z) detected by the sensor arrays 340, 350 may be compared to clamp position data (i.e., Z-direction, R) by the clamp controller 360_X、R_Y) Compared and reduced by the clamp controller 360 for each detection period (e.g., 1.0 ms). In some embodiments, the chuck controller 360 may be configured to control the reticle stage 200 and/or the chuck 300 to allow compliant movement of the chuck 300 until the chuck front side 302 and the reticle back side 409 are fully in contact and coplanar, and/or to reduce contact forces and minimize particle generation between the reticle 408 and the chuck 300. For example, the clamp controller 360 may adjust the clamp 300 position (i.e., Z-direction, R-direction) by adjusting the clamp position for each sensor array 340, 350 detection period (e.g., 1.0ms)_X、R_Y) To calculate and reduce stress (i.e., σ X, σ Y, σ Z) or strain (i.e., ε X, ε Y, ε Z) from either the reticle backside 409 or the chuck front side 302.

As shown in fig. 11, the fixture 300 may include a sensor array 340. The sensor array 340 may be resistive. The sensor array 340 may include one or more planar strain gauges 342, 344. In some embodiments, the sensor array 340 may be disposed on the fixture front side 302. In some embodiments, the sensor array 340 may be disposed in the fixture 300. In some embodiments, the sensor array 340 may be disposed between the fixture 300 and the reticle stage 200. In some embodiments, the planar strain gauges 342, 344 may be symmetrically arranged or arranged in a patterned array. For example, as shown in fig. 11, the planar strain gauges 342, 344 may be arranged in a 3 x 4 array. In some embodiments, the sensor array 340 may be used to monitor reticle forces (i.e., σ X, σ Y, σ Z, ε X, ε Y, ε Z) in real-time (e.g., 1.0 ms). For example, the sensor array 340 may monitor local force variations during a reticle exchange process. In some embodiments, the sensor array 340 may be arranged to improve sensitivity to reticle backside 409 forces (i.e., σ X, σ Y, σ Z, ε X, ε Y, ε Z). For example, the sensor array 340 may include a plurality of strain gauges 342, 344 disposed around the periphery or edge of the clamp front side 302.

As shown in fig. 12, the fixture 300 may include a sensor array 350. Sensor array 350 may be resistive. Sensor array 350 may include one or more planar resistors 352, 354, 356, 358. In some embodiments, the planar resistors 352, 354, 356, 358 may be lithographically patterned resistors. In some embodiments, the planar resistors 352, 354, 356, 358 may be configured to change resistance in proportion to applied pressure. For example, the planar resistors 352, 354, 356, 358 may be a piezoelectric material (e.g., lead zirconate titanate (PZT), gallium phosphate (GaPO)₄) Quartz, lead magnesium niobate-lead titanate (PMN-PT), etc.).

In some embodiments, the sensor array 350 may be disposed on the fixture front side 302. For example, sensor array 350 may be lithographically patterned on fixture front side 302. In some embodiments, sensor array 350 may be disposed in fixture 300. In some embodiments, the sensor array 350 may be disposed between the fixture 300 and the reticle stage 200.

In some embodiments, the planar resistors 352, 354, 356, 358 may be arranged symmetrically or in a patterned array. For example, as shown in fig. 12, the planar resistors 352, 354, 356, 358 may be arranged in a 2 x 2 array. In some embodiments, sensor array 350 may be used to monitor reticle forces (i.e., σ X, σ Y, σ Z, ε X, ε Y, ε Z) in real time (e.g., 1.0 ms). For example, the sensor array 350 may monitor local force variations during a reticle exchange process. In some embodiments, the sensor array 350 may be arranged to improve sensitivity to reticle backside 409 forces (i.e., σ X, σ Y, σ Z, ε X, ε Y, ε Z). For example, the sensor array 350 may include a plurality of planar resistors 352, 354, 356, 358 disposed around the periphery or edge of the clamp front side 302.

Exemplary reticle exchange device

Fig. 13 and 14 show schematic illustrations of an example reticle exchange tool 100' according to some embodiments of the present disclosure. The reticle exchange tool 100 'shown in fig. 13 and 14 is similar to the reticle exchange tool 100 shown in fig. 4 and 5, except that the reticle exchange tool 100' may include a plate 500. Reticle exchange tool 100' may be configured to minimize reticle exchange time, particle generation, and contact forces or stresses from the chuck 300 and/or reticle 408 to reduce damage to the chuck 300 and reticle 408 and increase overall throughput during reticle exchange (e.g., in lithography tool LA).

As shown in fig. 13 and 14, reticle exchange tool 100' may include reticle stage 200, clamp 300, in-vacuum robot 400, and plate 500. Plate 500 may be configured to provide a Reticle Microenvironment (RME) to reticle 408, reticle base plate 406, and in-vacuum robot 400. The plate 500 may be arranged between the reticle stage 200 with the clamp 300 and the in-vacuum robot 400. Plate 500 may include a plate front side 502, a plate back side 504, a reticle exchange port 506, a first reticle floor chamber 508, a second reticle floor chamber 510, and a third reticle floor chamber 512. Reticle exchange port 506 may be configured to receive reticle 408 on reticle base 406 during a reticle exchange process. The board back side 504 is opposite the board front side 502. The board front side 502 faces vertically toward the top platform surface 202 and the clamp front side 302.

In some embodiments, as shown in fig. 13, reticle exchange port 506 and reticle substrate chambers 508, 510, 512 may be symmetrically arranged. For example, reticle exchange port 506 and reticle substrate chambers 508, 510, 512 may correspond to reticle transport 402, e.g., where reticle transport arms 404 are spaced approximately 90 degrees apart from each other. In some embodiments, reticle handler arm 404, reticle exchange port 506, and reticle substrate chambers 508, 510, 512 may be arranged asymmetrically with respect to reticle handler 402.

During a reticle exchange process, reticle transport arm 404 of reticle transport 402 positions reticle 408 on reticle base plate 406 through reticle exchange port 506 toward fixture 300 in reticle exchange region 410. As described above, reticle handoff from reticle handler 402 to gripper 300 includes unknown reticle positional offsets including a reticle vertical distance offset (i.e., Z-direction offset) and a reticle tilt angle offset (i.e., R)_XOffset and R_YOffset).

In some embodiments, as shown in fig. 14, reticle exchange tool 100' may include a plate controller 560. A plate controller 560 may be coupled to the plate 500 and may be configured to control the position of the clamp 300 and/or the reticle handler arm 404 in the reticle exchange area 410. For example, plate controller 560 may be configured to control reticle stage 200 to allow compliant movement of chuck 300. In some embodiments, plate controller 560 may be coupled to servo motors or servo actuators (i.e., X-direction, Y-direction, Z-direction, R-direction) of reticle stage 200 and/or chuck 300_X、R_Y、R_Z). For example, plate controller 560 may control translation of and about the X, Y, and Z axes (i.e., X, Y, Z directions) of reticle stage 200 with chuck 300_X、R_Y、R_Z) Wherein the x-axis, y-axis, and z-axis are orthogonal coordinates.

Exemplary plate for real-time reticle position detection

Fig. 14 and 15 show schematic illustrations of an example plate 500 of an example reticle exchange tool 100', according to some embodiments of the present disclosure. Reticle exchange tool 100' may include a plate 500, sensor arrays 520, 530, and a plate controller 560. Sensor arrays 520, 530 may be configured to detect the position of reticle 408 through reticle exchange port 506 and/or in reticle exchange area 410 during a reticle exchange process.

For example, the position of reticle 408 may include a vertical distance between reticle backside 409 and chuck front side 302 (i.e., the Z direction), and a relative tilt angle between reticle backside 409 and chuck front side 302 (i.e., R)_XAnd R_Y). The sensor arrays 520, 530 may be disposed on or in the plate 500 near the reticle exchange region 410.

For example, as shown in fig. 14, sensor arrays 520, 530 may be disposed in reticle exchange port 506, e.g., along an interior surface 507 of reticle exchange port 506 between plate front side 502 and plate back side 504. The sensor arrays 520, 530 may be configured to detect reticle position (i.e., Z-direction, R)_X、R_Y). The plate controller 560 may be coupled to the sensor arrays 520, 530, and may be configured to be based on a reticle position (i.e., Z-direction, R-direction) detected by the sensor arrays 520, 530_X、R_Y) To calculate and control the position of the chuck 300 and/or reticle handler arm 404.

In some embodiments, board controller 560 may be disposed on or in board 500. In some embodiments, plate controller 560 may be coupled to plate 500, reticle stage 200, reticle handler arm 404, and/or clamp 300. For example, plate controller 560 may be electrically or wirelessly (e.g., radio frequency) coupled to plate 500, reticle stage 200, reticle handler arm 404, and/or chuck 300. In some embodiments, plate controller 560 may be configured to correct vertical distance offset (i.e., Z-direction offset) and relative tilt angle offset (i.e., R-direction offset) between reticle backside 409 and chuck front side 302 in real time_XOffset and R_YOffset). For example, reticle position data (i.e., Z-direction, R) detected by the sensor arrays 520, 530_X、R_Y) May be controlled by the board controller 560 with the fixture position data (i.e., Z-direction, R)_X、R_Y) Compared, to calculate the position offset (i.e.,z-direction offset, R_XOffset, R_YOffset) that may be reduced for each detection period (e.g., 1.0 ms). In some embodiments, the plate controller 560 may be configured to control the reticle stage 200, the reticle handler arm 404, and/or the gripper 300 to allow compliant movement of the gripper 300 until the gripper front side 302 and the reticle back side 409 are fully in contact and coplanar, and/or to reduce the contact force and minimize particle generation between the reticle 408 and the gripper 300. For example, the board controller 560 may adjust the position (i.e., Z-direction, R-direction) of the jig 300 by detecting a period (e.g., 1.0ms) for each sensor array 520, 530_X、R_Y) To calculate and reduce the positional offset (i.e., Z-direction offset, R) between reticle backside 409 and chuck front side 302_XOffset, R_YOffset).

In some embodiments, the plate controller 560 may be configured to move the reticle stage 200 or reticle handler arm 404 at a first speed until the sensor arrays 520, 530 detect the reticle position (i.e., Z-direction, R-direction)_X、R_Y) And then move the reticle stage 200 or reticle handler arm 404 at a second speed that is less than the first speed. For example, during the approach configuration 20, the reticle stage 200 with the clamp 300 may be moved substantially in the vertical direction (i.e., Z-direction) at a first speed (e.g., 1.0m/s) until the sensor array 520, 530 detects a threshold (e.g., predetermined) signal (i.e., Z-direction) of the reticle backside 409, at which time the plate controller 560 controls and moves the reticle stage 200 at a second speed (e.g., 0.1 mm/s). In some embodiments, reticle backside 409 damage may be mitigated by reducing the velocity or speed of reticle stage 200 and/or chuck 300 during the first contact (i.e., first contact configuration 30). In some embodiments, the lifetime of reticle backside 409 may be increased by alternating the areas on reticle backside 409 that are first contacted (i.e., during first contact configuration 30). In some embodiments, a partially damaged reticle 408 or fixture 300 may be safely used by changing the load zone or load conditions.

As shown in fig. 14 and 15, the board 500 may include a sensor array 520. The sensor array 520 may be optical. The sensor array 520 may include a light source 522 and one or more light detectors 524, 526. For example, the light source 522 may be a laser, an LED, a structured light projector, or a Diffractive Optical Element (DOE), and the light detectors 524, 526 may be photodiodes (e.g., quadrant APDs) or cameras.

In some embodiments, the light source 522 may be directed toward the reticle backside 409 and the light reflectivity of the light source 522 off the reticle backside 409 may be detected by the photodetectors 524, 526 to determine the reticle position (i.e., Z-direction, R) based on the location of the light reflection on the photodetectors 524, 526_X、R_Y). For example, the light source 522 may be directed toward the reticle backside 409, e.g., at an acute angle (e.g., 45 degrees) with respect to the jig front side 302.

In some embodiments, the sensor array 520 may be disposed on the board 500. In some embodiments, sensor array 520 may be disposed in reticle exchange port 506 of plate 500, or recessed into reticle exchange port 506 of plate 500, for example, along an interior surface 507 of reticle exchange port 506 between plate front side 502 and plate back side 504. In some embodiments, the light source 522 and light detectors 524, 526 may be symmetrically arranged. For example, as shown in fig. 14 and 15, light source 522 and light detectors 524, 526 may be arranged along horizontal (i.e., Y-direction) centerlines of reticle exchange port 506 along opposite sides of interior surface 507.

In some embodiments, the light source 522 may be a plurality of lasers and may be configured for structured light stereo detection via laser interference. For example, the light source 522 may include two planar laser beam fronts whose interference may be detected by one or more photodetectors 524, 526 to measure the three-dimensional shape (i.e., Z-direction, R) of the reticle backside 409_X、R_Y). In some embodiments, light source 522 may be a projected light pattern and may be configured for structured light stereo detection via pattern projection. For example, the light source 522 may include a stripe pattern (e.g., parallel stripes) with a shift of the stripe patternMay be detected by the photodetectors 524, 526 to measure the three-dimensional shape (i.e., Z-direction, R) of the reticle backside 409_X、R_Y). In some embodiments, the light source 522 may be a DOE pattern projected onto the reticle backside 409 and the light detectors 524, 526 may be a stereo camera pair opposite the light source 522. For example, the reflectivity of the light source 522 off the reticle backside 409 may determine the tilt angle (i.e., R) of the reticle backside 409_XAnd R_Y)。

In some embodiments, the light source 522 and light detectors 524, 526 may be optical fibers. In some embodiments, sensor array 520 may include light source 522 and light detector 524. For example, the light detector 524 may include a double prism to detect two shifted images of the fringe pattern from the light source 522 with a single light detector 524 for structured light stereo detection and tilt angle calculation (i.e., R) of the reticle backside 409_XAnd R_Y). In some embodiments, the light source 522 and light detectors 524, 526 may be time synchronized. For example, the light source 522 may include a fringe pattern (e.g., parallel stripes), the displacement of which may be synchronously detected by the photodetectors 524, 526 to measure the stereo depth and tilt angle (i.e., Z-direction, R-direction) of the reticle backside 409_X、R_Y)。

As shown in fig. 14 and 15, the board 500 may include a sensor array 530. The sensor array 530 may be optical. Sensor array 530 may include one or more light sensors 532, 534, 536, 538. In some embodiments, the light sensors 532, 534, 536, 538 may be confocal sensors. For example, the light sensors 532, 534, 536, 538 may be time-synchronized confocal sensors with a narrow measurement range (e.g., 22.0mm) or a wide measurement range (e.g., 30.0 mm). By using a time-synchronized confocal sensor, the difference in detection time can be measured and used to calculate the position of the reticle backside 409 (i.e., Z-direction, R)_X、R_Y). In some embodiments, the one or more light sensors 532, 534, 536, 538 may be symmetrically arranged. For example, as shown in fig. 15, sensor array 530 may surround interior surface 507 of reticle exchange port 506Arranged as a quadrilateral with two photosensors 532, 534 on a first side of reticle exchange port 506 and two photosensors 536, 538 on a second side of reticle exchange port 506 and opposite photosensors 532, 534.

In some embodiments, spatial constraints of the reticle exchange area 410 may be used to calculate the position (i.e., Z-direction, R) of the reticle backside 409_X、R_Y). For example, sensor array 530 may monitor translation of reticle base 406 through an outer periphery (e.g., edge) of reticle exchange port 506, an outer periphery (e.g., edge) of reticle 408, or a leading edge of reticle backside 409_XAnd R_Y) Whether a predetermined threshold is exceeded. In some embodiments, the sensor array 530 may be a fiber optic system. For example, sensor array 530 may include a single pulsed laser source (e.g., a 10kHz NIR laser) coupled to four optical couplers with vacuum ports, each including a collimator and a confocal sensor located in reticle exchange port 506. The illustrated fiber optic system detection output may be received by a board controller 560 (e.g., a Field Programmable Gate Array (FPGA)) to calculate the position (i.e., Z-direction, R) of the reticle backside 409_X、R_Y)。

As shown in fig. 14 and 15, the board 500 may include sensor arrays 520, 530. To achieve reticle backside 409 position (i.e., Z-direction, R)_X、R_Y) For better accuracy and detection, the board 500 may include multiple sensor arrays 520, 530. In some embodiments, the board controller 560 may receive and analyze multiple signals from multiple sensor arrays 520, 530 in real time (e.g., 1.0 ms).

Exemplary plate for reticle position calibration

Fig. 15 and 16 illustrate an example of an example reticle exchange tool 100' according to some embodiments of the present disclosureA schematic illustration of a plate 500. Reticle exchange tool 100' may include a plate 500, sensor arrays 540, 550, and a plate controller 560. Sensor arrays 540, 550 may be configured to calibrate the position of reticle 408 in reticle exchange port 506 and/or in reticle exchange region 410 based on the fixed plane of sensor arrays 540, 550 during a reticle exchange process. For example, the position of reticle 408 may include the vertical distance between reticle backside 409 and chuck front side 302 (i.e., the Z direction), and the relative tilt angle between reticle backside 409 and chuck front side 302 (i.e., R)_XAnd R_Y). The sensor arrays 540, 550 may be disposed on the board back side 504. For example, as shown in fig. 15, sensor arrays 540, 550 may be disposed on plate backside 504 remote from reticle exchange port 506. The sensor arrays 540, 550 may be configured to calibrate the reticle position (i.e., Z-direction, R-direction)_X、R_Y). The plate controller 560 may be coupled to the sensor arrays 540, 550 and may be configured to calibrate the reticle position based on the calibrated reticle position (i.e., calibrated Z-direction, calibrated R) detected by the sensor arrays 540, 550_XCalibrated R_Y) To calculate and control the position of the chuck 300 and/or reticle handler arm 404.

In some embodiments, board controller 560 may be disposed on board 500. In some embodiments, plate controller 560 may be coupled to plate 500 and/or clamp 300. For example, board controller 560 may be electrically or wirelessly (e.g., radio frequency) coupled to board 500 and/or fixture 300. In some embodiments, the plate controller 560 may be configured to base the vertical distance offset (i.e., Z-direction offset) and the relative tilt angle offset (i.e., R-direction offset) between the reticle backside 409 or reticle base plate front side 407 and the fixed plane of the sensor arrays 540, 550_XOffset and R_YOffset) to correct for vertical distance offset (i.e., Z-direction offset) and relative tilt angle offset (i.e., R-direction offset) between reticle backside 409 and chuck front side 302_XOffset and R_YOffset). For example, the sensor array 540, 550 may be calibrated by the process tool reticle, and subsequently, the calibrated reticle position detected by the sensor array 540, 550Data (i.e., calibrated Z-direction, calibrated R)_XCalibrated R_Y) May be controlled by the board controller 560 with the fixture position data (i.e., Z-direction, R)_X、R_Y) Compared to calculate the jig position offset (i.e., Z-direction offset, R)_XOffset, R_YOffset) that may be reduced or corrected prior to loading reticle 408 onto reticle base plate 406. Such a calibration process may be performed for each reticle 408 in reticle exchange area 410 prior to a reticle exchange process.

In some embodiments, the plate controller 560 may be configured to control the reticle stage 200, the reticle handler arm 404, and/or the gripper 300 to allow compliant movement of the gripper 300 until the gripper front side 302 and the reticle back side 409 are fully in contact and coplanar, and/or to reduce the contact force and minimize particle generation between the reticle 408 and the gripper 300. For example, plate controller 560 may determine the position of reticle back side 409 or reticle backplane front side 407 and the fixed plane of sensor array 540, 550 by calibrating the position offset (i.e., Z-direction offset, R-direction offset) based on a position offset detected by sensor array 540, 550 before reticle 408 is loaded into reticle exchange area 410_XOffset, R_YOffset) to adjust the position (i.e., Z-direction, R) of the jig 300_X、R_Y) To calculate and reduce the positional offset (i.e., Z-direction offset, R) between reticle backside 409 and chuck front side 302_XOffset, R_YOffset).

In some embodiments, plate controller 560 may be configured to move reticle stage 200 or reticle handler arm 404 at a first speed until a calibrated reticle position (i.e., a calibrated Z-direction, a calibrated R) is reached_XCalibrated R_Y) To the reticle stage 200, and then moving the reticle stage 200 at a second speed that is less than the first speed. For example, during the approach configuration 20, the reticle stage 200 with the clamp 300 or the reticle handler arm 404 with the reticle 408 may be moved substantially in the vertical direction (i.e., Z-direction) at a first speed (e.g., 1.0m/s) until a calibrated reticle position (i.e., a calibrated reticle position) is reached (i.e., a calibrated reticle position is reachedCalibrated Z-direction, calibrated R_XCalibrated R_Y) By this time, the plate controller 560 controls or moves the reticle stage 200 or reticle handler arm 404 at a second speed (e.g., 0.1 mm/s). In some examples, reticle backside 409 damage may be detected by arriving at a calibrated reticle position (i.e., a calibrated Z-direction, a calibrated R) before a first contact (i.e., first contact configuration 30) based on_XCalibrated R_Y) The velocity or speed of the reticle stage 200, reticle handler arm 404, and/or clamp 300 is reduced.

As shown in fig. 15 and 16, the board 500 may include a sensor array 540. The sensor array 540 may be capacitive. The sensor array 540 may include one or more planar electrodes 542, 544, 546, 548. In some embodiments, as shown in fig. 15, a sensor array 540 may be disposed on the board back side 504. For example, the sensor array 540 may be disposed at an angle 562 (e.g., 45 degrees) relative to a horizontal (i.e., Y-direction) axis of the reticle handler arm 404 of the reticle handler 402, such that, for example, the sensor array 540 is symmetrically disposed between the second reticle floor chamber 510 and the third reticle floor chamber 512. In some embodiments, the planar electrodes 542, 544, 546, 548 may be symmetrically arranged. For example, as shown in fig. 15, the planar electrodes 542, 544, 546, 548 may be spaced about 90 degrees apart. In some embodiments, the planar electrodes 542, 544, 546, 548 form a fixed plane, such as the plate back side 504, wherein each planar electrode 542, 544, 546, 548 is coplanar.

In some embodiments, the sensor array 540 may be configured to simultaneously measure the reticle backside 409 or the reticle backplane front side 407 to determine a relative positional offset (i.e., Z-direction offset, R-direction offset) between the reticle backside 409 or the reticle backplane front side 407 and a fixed plane of the sensor array 540_XOffset, R_YOffset). For example, the sensor array 540 may detect the capacitance of each planar electrode 542, 544, 546, 548, and the board controller 560 may calculate the difference in capacitance between each planar electrode 542, 544, 546, 548 so as to be relative to a fixed plane of the sensor array 540(e.g., plate backside 504) to determine the reticle backside 409 or reticle backplane frontside 407 position (i.e., Z-direction, R-direction)_X、R_Y). The plate controller 560 may calculate the offset position and later adjust the reticle stage 200, reticle handler arm 404, and/or gripper 300 to reduce the offset when loading the reticle 408 in the reticle exchange region 410 during the multi-stage movement.

As shown in fig. 15 and 16, the board 500 may include a sensor array 550. The sensor array 550 may be optical. The sensor array 550 may include one or more light sensors 552, 554, 556. In some embodiments, the light sensors 552, 554, 556 may be confocal sensors. For example, the light sensors 552, 554, 556 may be time-synchronized confocal sensors with a very narrow measurement range (e.g., 8.0mm) or narrow measurement range (e.g., 22.0 mm). By using a time synchronized confocal sensor, the difference in detection time can be measured and used to detect the calibrated position (i.e., calibrated Z-direction, calibrated R) of the reticle backside 409 or reticle backplane front side 407_XCalibrated R_Y). In some embodiments, as shown in fig. 15, sensor array 550 may be disposed on board back side 504. For example, the sensor array 550 may be disposed at an angle 562 (e.g., 45 degrees) relative to a horizontal (i.e., Y-direction) axis of the reticle transport arm 404 of the reticle transport 402, such that, for example, the sensor array 550 is symmetrically disposed between the first reticle floor chamber 508 and the second reticle floor chamber 510. In some embodiments, the light sensors 552, 554, 556 may be symmetrically arranged. For example, as shown in fig. 15, the light sensors 552, 554, 556 may be arranged at the intersection of isosceles triangles, i.e., corner points, such that the distance (e.g., 122.0mm) between the two light sensors 554, 556 is equal to the height (e.g., 122.0mm) separating the other light sensor 552. In some embodiments, the photosensors 552, 554, 556 form a fixed plane, such as the board back side 504, where each photosensor 552, 554, 556 is coplanar.

In some embodiments, sensor array 550 may be configured to simultaneously measure reticle backside 409 orThe reticle backplane front side 407 to determine a relative positional offset (i.e., Z-direction offset, R) between the reticle back side 409 or the reticle backplane front side 407 and a fixed plane of the sensor array 550_XOffset, R_YOffset). For example, the sensor array 550 may detect the refractive index based on the wavelength of each light sensor 552, 554, 556, and the plate controller 560 may calculate the difference in refractive index based on the wavelength between each light sensor 552, 554, 556 to determine the reticle backside 409 or reticle base plate frontside 407 position (i.e., Z-direction, R-direction) relative to a fixed plane of the sensor array 550 (e.g., the plate backside 504)_X、R_Y). The plate controller 560 may calculate the offset position and later adjust the reticle stage 200, reticle handler arm 404, and/or gripper 300 to reduce the offset when loading the reticle 408 in the reticle exchange region 410 during the multi-stage movement.

As shown in fig. 16, reticle exchange tool 100' may be in a calibration configuration 60. In the calibration configuration 60, the reticle backside 409 or the reticle backplane front side 407 may be measured by the sensor arrays 540, 550 and calibrated by the plate controller 560. In some embodiments, the sensor arrays 540, 550 may have been previously calibrated by the process tool reticle. For example, the process tool reticle may be used to measure the reticle base plate front side 407 position (i.e., Z-direction, R) during multi-stage movement by subsequently using the sensor arrays 540, 550_X、R_Y) To measure the fixture front side 302 position (i.e., Z-direction, R)_X、R_Y). In some embodiments, the sensor arrays 540, 550 may be configured to simultaneously measure the reticle backside 409 or reticle backplane front side 407 to determine a relative positional offset (i.e., Z-direction offset, R-direction offset) between the reticle backside 409 or reticle backplane front side 407 and a fixed plane of the sensor arrays 540, 550_XOffset, R_YOffset). For example, the plate controller 560 may determine the reticle backside 409 or reticle backplane front side 407 position (i.e., Z-direction, R) relative to a fixed plane of the sensor arrays 540, 550 (e.g., the plate backside 504)_X、R_Y) And calculates an offset position based on the measurements of the sensor arrays 540, 550. As shown in fig. 15, the maskThe reticle exchange apparatus 100' may be in a reticle exchange configuration 50. In reticle exchange configuration 50, plate controller 560 may adjust reticle stage 200, reticle handler arm 404, and/or clamp 300 during multi-stage movement while loading reticle 408 in reticle exchange region 410 to reduce offset positions previously calculated (e.g., in calibration configuration 60).

The method of operating a reticle exchange tool 100, 100', 100 "may be accomplished in accordance with the manner of operation disclosed herein. In some embodiments, reticle exchange tool 100, 100', 100 ″ may be configured to reduce contact forces and minimize particle generation between reticle 408 and chuck 300 on reticle stage 200. In some embodiments, this may be done, for example, by detecting reticle backside 409 or reticle base plate front side 407 position (i.e., Z-direction, R-direction) using sensor arrays 310, 320, 330, 340, 350, 520, 530, 540, 550_X、R_Y) To complete. In some embodiments, the vertical distance offset (i.e., Z-direction offset) and the relative tilt angle offset (i.e., R-direction offset) between reticle backside 409 and chuck front side 302_XOffset and R_YOffset) may be based on reticle backside 409 or reticle backplane front side 407 position (i.e., Z-direction, R-direction), for example, by the clamp controller 360 and/or the plate controller 560_X、R_Y) To calculate. In some embodiments, reticle stage 200, chuck 300, reticle handler arm 404, and/or reticle 408 may be adjusted, for example, by chuck controller 360 and/or plate controller 560, to reduce vertical distance offset (i.e., Z-direction offset) and relative tilt angle offset (i.e., R-direction offset)_XOffset and R_YOffset) until reticle backside 409 and chuck front side 302 contact and are coplanar. In some embodiments, the following may be performed in real time (e.g., 1.0 ms): detecting reticle backside 409 or reticle base plate frontside 407 position (i.e., Z-direction, R-direction) using sensor arrays 310, 320, 330, 340, 350, 520, 530, 540, 550_X、R_Y) (ii) a Calculate the vertical distance offset (i.e., Z-direction offset) and relative tilt angle offset (i.e., R) between reticle backside 409 and chuck front side 302_XOffset and R_YOffset); and adjusting the reticle stage 200,The clamp 300, reticle handler arm 404, and/or reticle 408 may be configured to reduce vertical distance offset (i.e., Z-direction offset) and relative tilt angle offset (i.e., R)_XOffset and R_YOffset) until reticle backside 409 and chuck front side 302 are in contact and coplanar. In some embodiments, reticle stage 200 may move at a first speed until sensor arrays 310, 320, 330, 340, 350, 520, 530, 540, 550 detect reticle backside 409 position (i.e., Z-direction, R-direction)_X、R_Y) And then move at a second speed less than the first speed.

Exemplary in-vacuum robot for real-time reticle position detection

Fig. 17 shows a schematic illustration of an example reticle exchange tool 100 "in accordance with some embodiments of the present disclosure. The reticle exchange tool 100 "shown in fig. 17 is similar to the reticle exchange tool 100 shown in fig. 4 and 5 and the reticle exchange tool 100' shown in fig. 13 and 14. Reticle exchange tool 100 "includes a reticle stage 200, a chuck 300, and an in-vacuum robot (IVR) 400. The IVR400 shown in fig. 17 is similar to the in-vacuum robot 400 shown in fig. 4 and 5 and the in-vacuum robot 400 shown in fig. 13 and 14, except that the reticle base plate 406 may include a first through-hole 412 and a second through-hole 413 for the first detection sensor 1702 and the second detection sensor 1706, respectively. IVR400 may be configured to minimize reticle exchange time, particle generation, and contact forces or stresses from the chuck 300 and/or reticle 408 to reduce damage to the chuck 300 and reticle 408 and increase overall throughput during reticle exchange (e.g., in a lithographic apparatus LA). In some embodiments, the IVR400 shown in fig. 17 may be incorporated into the reticle exchange tool 100 shown in fig. 4 and 5 or the reticle exchange tool 100' shown in fig. 13 and 14.

Fig. 17 and 18 show schematic illustrations of an example IVR400 of an example reticle exchange tool 100 ", according to some embodiments of the present disclosure. Fig. 18 depicts a schematic enlarged cross-sectional view of a region 1800 shown in fig. 17 of an IVR400 including a first optical system 1720 (the first optical system 1720 including one or more beam shaping optics 1722, 1724, 1726, 1728, 1730), according to some embodiments of the present disclosure.

The IVR400 may include a reticle handler 402. The reticle transport 402 may include one or more reticle transport arms 404. In some embodiments, the reticle handler 402 may be a Rapid Exchange Device (RED) configured to rotate efficiently and minimize reticle exchange time. For example, reticle handler 402 may save time by moving multiple reticles from one location to another location substantially simultaneously rather than sequentially. The reticle handler arm 404 may include a reticle base plate 406.

Reticle base 406 may be configured to hold an object, such as reticle 408. In some embodiments, reticle base plate 406 may be an extreme ultraviolet (EIP) chamber of a reticle. In some embodiments, reticle base 406 includes a reticle base front side 407, and reticle 408 includes a reticle backside 409 and a reticle front side 411. As shown in fig. 17, reticle base plate 406 may include a first through-hole 412 and a second through-hole 413.

Reticle exchange tool 100 ″ may include a reticle exchange region 410, the reticle exchange region 410 being a cross-sectional area between the clamp 300, the reticle 408, the reticle base plate 406, and a portion of the reticle handler arm 404 during a reticle exchange process.

As shown in fig. 17, the IVR400 may include a first detection sensor 1702 and a second detection sensor 1706. The first detection sensor 1702 is similar to the second detection sensor 1706. A first detection sensor 1702 is configured to detect a position of the reticle 408 in the reticle exchange region 410 through a first through-hole 412 of the reticle base plate 406 during a reticle exchange process. The second detection sensor 1706 is configured to detect a position of the reticle 408 in the reticle exchange area 410 through a second through-hole 413 of the reticle base plate 406 during a reticle exchange process.

For example, the position of reticle 408 may include reticle front side 411 and a first detection sensorA vertical distance (i.e., Z direction) between a fixed plane (i.e., reference position) of the tool 1702, and a relative tilt angle (i.e., R) between the reticle front side 411 and a fixed plane (i.e., reference position) of the first detection sensor 1702_XAnd R_Y). The first detection sensor 1702 and the second detection sensor 1706 may be disposed on or in the IVR400 near the reticle exchange area 410.

As shown in fig. 17, the first detection sensor 1702 includes a first light source 1740 and a first light detector 1732. For example, the first light source 1740 may be a laser (e.g., visible spectrum (VIS), Near Infrared (NIR), Infrared (IR)), an LED, a structured light projector, or a Diffractive Optical Element (DOE), and the first light detector 1732 may be a photodiode (e.g., quadrant APD) or a camera. The first light source 1740 provides a first illumination beam 1703. The first illumination beam 1703 is configured to be focused through the first through-hole 412 and onto the reticle front side 411. The first illumination beam 1703 may be scattered off the reticle front side 411 to produce a first signal beam 1704. First signal beam 1704 may be detected by first optical detector 1732. For example, a first light source 1740 may be directed toward the reticle front side 411, and light reflections of the first light source 1740 (i.e., the first signal beam 1704) exiting from the reticle front side 411 may be detected by the first photo-detector 1732 to determine the reticle position (i.e., Z-direction, R-direction) based on the location and/or intensity of the first signal beam 1704 on the first photo-detector 1732_X、R_Y)。

In some embodiments, the first detection sensor 1702 may include a first beam splitter 1735 between the first light source 1740 and the first light detector 1732. First beam splitter 1735 may be used for a more compact design of first detection sensor 1702. First beam splitter 1735 may transmit first illumination beam 1703 from first light source 1740 and reflect first signal beam 1704 to first photo-detector 1732. In some embodiments, the first beam splitter 1735 may be a polarizing beam splitter, and may polarize the first illumination beam 1703. In some embodiments, the first detection sensor 1702 may include a first optical system 1720. The first optical system 1720 may include one or more beam shaping optics. For example, as shown in fig. 18, first optical system 1720 may include first optical device 1722, second optical device 1724, third optical device 1726, fourth optical device 1728, and/or fifth optical device 1730. First optic 1722, second optic 1724, third optic 1726, fourth optic 1728, and/or fifth optic 1730 may include plano-concave lenses, plano-convex lenses, biconcave lenses, biconvex lenses, positive meniscus lenses, negative meniscus lenses, positive achromatic lenses, negative achromatic lenses, beam expanders, collimators, or some combination thereof.

As shown in fig. 17, second detection sensor 1706 includes a second light source 1770 and a second light detector 1762. For example, second light source 1770 can be a laser (e.g., visible spectrum (VIS), Near Infrared (NIR), Infrared (IR)), an LED, a structured light projector, or a Diffractive Optical Element (DOE), and second light detector 1762 can be a photodiode (e.g., quadrant APD) or a camera. A second light source 1770 provides a second illumination beam 1707. A second illumination beam 1707 is configured to be focused through the second through hole 413 onto the reticle front side 411. The second illumination beam 1707 may be scattered off the reticle front side 411 to produce a second signal beam 1708. Second signal beam 1708 may be detected by a second optical detector 1762. For example, a second light source 1770 may be directed toward reticle front side 411, and light reflections of second light source 1770 off reticle front side 411 (i.e., second signal beam 1708) may be detected by second photodetector 1762 to determine reticle position (i.e., Z-direction, R-direction) based on the location and/or intensity of second signal beam 1708 on second photodetector 1762_X、R_Y)。

In some embodiments, second detection sensor 1706 can include a second beam splitter 1765 between second light source 1770 and second light detector 1762. Second beam splitter 1765 may be used for a more compact design of second detection sensor 1706. Second beam splitter 1765 may transmit second illumination beam 1707 from second light source 1770 and reflect second signal beam 1708 to second light detector 1762. In some embodiments, the second beam splitter 1765 may be a polarizing beam splitter, and may polarize the second illumination beam 1707. In some embodiments, the second detection sensor 1706 may include a second optical system 1750. Second optical system 1750 may include one or more beam shaping optics. For example, as shown in fig. 18, second optical system 1750 may be similarly arranged as first optical system 1720 comprising first optical device 1722, second optical device 1724, third optical device 1726, fourth optical device 1728, and/or fifth optical device 1730.

In some embodiments, as shown in fig. 17, reticle exchange tool 100 "may include a controller 1780. The controller 1780 may be coupled to the first detection sensor 1702 and/or the second detection sensor 1706. The first detection sensor 1702 and the second detection sensor 1706 may be configured to detect the reticle position (i.e., Z-direction, R-direction)_X、R_Y). The controller 1780 may be coupled to the first detection sensor 1702 and the second detection sensor 1706 and may be configured to determine a position of the reticle based on the reticle position (i.e., Z-direction, R-direction) detected by the first detection sensor 1702 and the second detection sensor 1706_X、R_Y) To calculate and control the position of the chuck 300 and/or reticle handler arm 404. In some embodiments, the first detection sensor 1702 and the second detection sensor 1706 may be disposed outside of the IVR 400.

In some embodiments, the controller 1780 may be provided external to the IVR 400. In some embodiments, the controller 1780 may be coupled to the plate 500, the reticle stage 200, the reticle handler arm 404, and/or the clamp 300. For example, the controller 1780 may be electrically or wirelessly (e.g., radio frequency) coupled to the plate 500, the reticle stage 200, the reticle handler arm 404, and/or the clamp 300. In some embodiments, the controller 1780 may be configured to correct for vertical distance offset (i.e., Z-direction offset) and relative tilt angle offset (i.e., R-direction offset) between the reticle front side 411 and the chuck front side 302 in real-time_XOffset and R_YOffset). For example, reticle position data (i.e., Z-direction, R-direction) detected by the first detection sensor 1702 and/or the second detection sensor 1706_X、R_Y) Can be controlled by the controller 1780 and the clamp position data (i.e., Z-direction, R)_X、R_Y) Compared to calculate the position offset (I.e. Z-direction offset, R_XOffset, R_YOffset) that may be reduced for each detection period (e.g., 1.0 ms). In some embodiments, the controller 1780 may be configured to control the reticle stage 200, the reticle handler arm 404, and/or the clamp 300 to allow compliant movement of the clamp 300 until the clamp front side 302 and the reticle back side 409 are fully in contact and coplanar, and/or to reduce contact forces and minimize particle generation between the reticle 408 and the clamp 300. For example, the controller 1780 may adjust the position (i.e., Z-direction, R-direction) of the jig 300 by detecting a period (e.g., 1.0ms) for each of the first detection sensor 1702 and the second detection sensor 1706_X、R_Y) To calculate and reduce the positional offset (i.e., Z-direction offset, R) between reticle backside 409 and chuck front side 302_XOffset, R_YOffset). In some embodiments, the controller 1780 may be configured to determine the position of the reticle 408 based on a first position (i.e., Z-direction, R) of the reticle 408 detected by the first detection sensor 1702_X、R_Y) And a second position (i.e., Z-direction, R) of reticle 408 detected by a second detection sensor 1706_X、R_Y) In real time, corrects for vertical distance offset (i.e., Z-direction offset) and relative tilt angle offset (i.e., R-direction offset) between reticle front side 411 and chuck front side 302_XOffset and R_YOffset).

In some embodiments, the controller 1780 may be configured to move the reticle stage 200 or reticle handler arm 404 at a first speed until the first detection sensor 1702 and/or the second detection sensor 1706 detects the reticle position (i.e., Z-direction, R-direction)_X、R_Y) And then move the reticle stage 200 or reticle handler arm 404 at a second speed that is less than the first speed. For example, during the approach configuration 20, the reticle stage 200 with the clamp 300 may be moved substantially in the vertical direction (i.e., Z-direction) at a first speed (e.g., 1.0m/s) until the first detection sensor 1702 and/or the second detection sensor 1706 detects a threshold (e.g., predetermined) signal (i.e., Z-direction) of the reticle front side 411, at which time the controller 1780 controls and at a second speed (e.g., Z-direction)0.1mm/s) moving reticle stage 200. In some embodiments, reticle 408 damage may be mitigated by reducing the velocity or speed of reticle stage 200 and/or chuck 300 during the first contact (i.e., first contact configuration 30). In some embodiments, the lifetime of reticle 408 may be increased by alternating the areas on reticle 408 that are first contacted (i.e., during first contact configuration 30). In some embodiments, a partially damaged reticle 408 or fixture 300 may be safely used by changing the load zone or load conditions.

In some embodiments, the first detection sensor 1702 and/or the second detection sensor 1706 may be disposed on the IVR 400. In some embodiments, the first detection sensor 1702 and/or the second detection sensor 1706 may be disposed in the reticle base 406 or IVR400, or recessed into the reticle base 406 or IVR400, for example, below an upper outer surface of the reticle handler arm 404. In some embodiments, the first detection sensor 1702 and the second detection sensor 1706 may be symmetrically arranged. For example, as shown in fig. 17, a first detection sensor 1702 and a second detection sensor 1706 may be arranged near two opposing sides of reticle base plate 406 with respect to a vertical (i.e., Z-direction) centerline of reticle base plate 406.

In some embodiments, the first light source 1740 and/or the second light source 1770 may be multiple lasers and may be configured for structured light stereo detection via laser interference. For example, the first light source 1740 may include two planar laser beam fronts, the interference of which may be detected by the first photo-detector 1732 to measure the three-dimensional shape (i.e., Z-direction, R) of the reticle front side 411_X、R_Y). In some embodiments, the first light source 1740 and/or the second light source 1770 may be a projected light pattern and may be configured for structured light stereo detection via pattern projection. For example, the first light source 1740 may include a fringe pattern (e.g., parallel stripes), the shift of which may be detected by the first photo-detector 1732 to measure the three-dimensional shape (i.e., Z-direction, R) of the reticle front side 411_X、R_Y). In some embodimentsIn some embodiments, first light source 1740 and/or second light source 1770 may be DOE patterns projected onto reticle front side 411, and first light detector 1732 and/or second light detector 1762 may be a stereo camera pair. For example, the first signal beam 1704 and/or the second signal beam 1708 exiting from the reticle front side 411 may determine the tilt angle (i.e., R) of the reticle front side 411_XAnd R_Y)。

In some embodiments, the first detection sensor 1702 and/or the second detection sensor 1706 may include an optical fiber. In some embodiments, the first detection sensor 1702 may include a first light source 1740 and a first light detector 1732. For example, the first photodetector 1732 may include a double prism to detect two shifted images of the fringe pattern from the first light source 1740 with the first photodetector 1732 for structured light stereo detection and tilt angle calculation (i.e., R) of the reticle front side 411_XAnd R_Y). In some embodiments, the first detection sensor 1702 and/or the second detection sensor 1706 may be time synchronized. For example, the first light source 1740 may include a fringe pattern (e.g., parallel stripes), the shift of which may be synchronously detected by the first photo-detector 1732 to measure the stereo depth and tilt angle (i.e., Z-direction, R-direction) of the reticle front side 411_X、R_Y)。

In some embodiments, the first detection sensor 1702 and/or the second detection sensor 1706 may be confocal sensors. For example, the first detection sensor 1702 and/or the second detection sensor 1706 may be time-synchronized confocal sensors having a narrow measurement range (e.g., 22.0mm) or a wide measurement range (e.g., 30.0 mm). By using a time-synchronized confocal sensor, the difference in detection time can be measured and used to calculate the position (i.e., Z-direction, R) of the reticle front side 411_X、R_Y). In some embodiments, the first detection sensor 1702 and the second detection sensor 1706 may be symmetrically arranged. In some embodiments, the first detection sensor 1702 and/or the second detection sensor 1706 may be acoustic sensors. For example, the first detection sensor 1702 and/or the second detection sensor 1706 may be narrow (e.g., 22.0mm) or wide in measurement rangeA time-synchronized ultrasonic sensor of a measurement range (for example, 30.0 mm).

In some embodiments, the first detection sensor 1702 and/or the second detection sensor 1706 may be high resolution optical sensors. For example, the first detection sensor 1702 and/or the second detection sensor 1706 may include a high resolution optical sensor for cadastral mapping, a remote driving assistance sensor (RPAS), a Parking Assistance Sensor (PAS), a reverse garage assistance sensor (RPAS), or some combination thereof.

Embodiments may be further described using the following aspects:

1. a clamping device, comprising:

a clamp;

a sensor disposed on a front side of the clamp, wherein the sensor is configured to detect a position of a reticle in a reticle exchange area during a reticle exchange process, wherein the position of the reticle comprises a vertical distance between a rear side of the reticle and the front side of the clamp and a relative inclination between the rear side of the reticle and the front side of the clamp; and

a controller coupled to the sensor and configured to control a position of the clamp based on the position of the reticle detected by the sensor.

2. The clamping apparatus of aspect 1, wherein the controller is configured to correct a vertical distance offset and a relative tilt angle offset between the backside of the reticle and the front side of the clamp in real time.

3. The clamping apparatus of aspect 1, wherein the controller is configured to control a reticle stage to allow compliant movement of the clamp until the front side of the clamp and the back side of the reticle are in contact and coplanar.

4. The clamp apparatus of aspect 1, wherein the controller is configured to reduce a contact force and minimize particle generation between the reticle and the clamp.

5. The clamping device of aspect 1, wherein the controller is configured to:

moving a reticle stage at a first speed until the position of the reticle is detected by the sensor; and

moving the reticle stage at a second speed, the first speed being greater than the second speed.

6. The clamping apparatus of aspect 1, wherein the sensor is capacitive and comprises a planar electrode.

7. The clamping apparatus of aspect 1, wherein:

the sensor is optical and comprises a light source and a light detector; and

the light source is directed at the backside of the reticle at an acute angle relative to the front side of the jig.

8. The clamping device of aspect 1, wherein the sensor is pressurized and comprises a barometer.

9. The clamping apparatus of aspect 1, wherein the sensor comprises a plurality of sensor arrays.

10. A clamping device, comprising:

a clamp;

a sensor disposed on a front side of the clamp, wherein the sensor is configured to detect a force of the reticle in a reticle exchange area during a reticle exchange process, wherein the force of the reticle comprises a stress or strain from a backside of the reticle or the front side of the clamp; and

a controller coupled to the sensor and configured to control a position of the clamp based on the force of the reticle detected by the sensor.

11. The clamp apparatus of aspect 10, wherein the controller is configured to correct stress or strain from the backside of the reticle or the front side of the clamp in real time.

12. The clamping apparatus of aspect 10, wherein the controller is configured to control a reticle stage to allow compliant movement of the clamp until the front side of the clamp and the back side of the reticle are in contact and coplanar.

13. The clamping apparatus of aspect 10, wherein the sensor is resistive and comprises a planar strain gauge.

14. The clamping device of aspect 10, wherein the sensor is resistive and includes a lithographically patterned resistor configured to change resistance in proportion to applied pressure.

15. A sheet apparatus, comprising:

a plate comprising a reticle exchange port;

a sensor disposed in the reticle exchange port, wherein the sensor is configured to detect a position of a reticle in a reticle exchange area during a reticle exchange process, wherein the position of the reticle comprises a vertical distance between a rear side of the reticle and a fixed plane of the sensor and a relative inclination between the rear side of the reticle and the fixed plane of the sensor; and

a controller coupled to the sensor and configured to control a position of a clamp based on the position of the reticle detected by the sensor.

16. The plate apparatus of aspect 15, wherein the controller is configured to correct a vertical distance offset and a relative tilt angle offset between the backside of the reticle and a front side of the chuck in real time.

17. The plate apparatus of aspect 15, wherein the controller is configured to control a reticle stage to allow compliant movement of the clamp until a front side of the clamp and the back side of the reticle are in contact and coplanar.

18. The plate apparatus of aspect 15 wherein:

the sensor is optical and comprises a light source and a light detector, and

the light source is a projected light pattern and is configured to allow structured light stereo detection by the sensor.

19. The plate apparatus of aspect 15 wherein the sensor is optical and comprises a confocal sensor configured to be time synchronized.

20. A sheet apparatus, comprising:

a plate comprising a reticle exchange port;

a sensor disposed on a backside of the plate and distal to the reticle exchange port, wherein the sensor is configured to calibrate a position of a reticle in a reticle exchange area based on a fixed plane of the sensor during a reticle exchange process, wherein the position of the reticle comprises a vertical distance between a backside of the reticle and the fixed plane of the sensor and a relative tilt angle between the backside of the reticle and the fixed plane of the sensor; and

a controller coupled to the sensor and configured to control a position of the clamp based on the position of the reticle detected by the sensor.

21. The plate apparatus of aspect 20, wherein the controller is configured to correct a vertical distance offset and a relative tilt angle offset between the backside of the reticle and a front side of the chuck based on a vertical distance offset and a relative tilt angle offset between the backside of the reticle and the fixed plane of the sensor.

22. The plate apparatus of aspect 20, wherein the sensor is configured to measure the backside of the reticle synchronously.

23. The plate apparatus of aspect 22 wherein the sensor is capacitive and comprises a planar electrode.

24. The plate apparatus of aspect 22 wherein the sensor array is optical and comprises one or more confocal sensors.

25. A method, comprising:

detecting a position of a reticle on a reticle stage with a sensor, the reticle stage comprising a clamp for the reticle, the position comprising a vertical distance between a rear side of the reticle and a front side of the clamp and a relative inclination between the rear side of the reticle and the front side of the clamp;

calculating a vertical distance offset and a relative tilt angle offset between the backside of the reticle and the front side of the clamp based on the position of the reticle detected by the sensor; and

adjusting the fixture or the reticle to reduce the vertical distance offset and the relative tilt angle offset until the back side of the reticle and the front side of the fixture are in contact and coplanar.

26. The method of aspect 25, wherein the detecting, calculating, and adjusting are performed in real-time.

27. The method of aspect 25, further comprising:

moving the reticle stage at a first speed until the position of the reticle is detected by the sensor; and

moving the reticle stage at a second speed, wherein the first speed is greater than the second speed.

28. An in-vacuum robotic device comprising:

a bottom plate including a first through hole;

a sensor disposed below the base plate, wherein the sensor is configured to detect a position of a reticle in a reticle exchange area through the first through-hole of the base plate during a reticle exchange process, wherein the position of the reticle comprises a vertical distance between a front side of the reticle and a fixed plane of the sensor and a relative inclination between the front side of the reticle and the fixed plane of the sensor; and

a controller coupled to the sensor and configured to control a position of a clamp based on the position of the reticle detected by the sensor.

29. The in-vacuum robotic apparatus of aspect 28, wherein the controller is configured to correct a vertical distance offset and a relative tilt angle offset between the front side of the reticle and a front side of the chuck in real time.

30. The in-vacuum robotic apparatus of aspect 28, wherein the controller is configured to control a reticle stage to allow compliant movement of the chuck until a front side of the chuck and a back side of the reticle are in contact and coplanar.

31. The in-vacuum robotic device of aspect 28, wherein the sensor is optical and comprises a confocal sensor configured to be time synchronized.

32. The in-vacuum robotic device of aspect 28, wherein the sensor is acoustic and comprises an ultrasonic sensor configured to be time synchronized.

33. The in-vacuum robotic device of aspect 28, wherein the sensor is optical and comprises a high resolution optical sensor for cadastral mapping, remote driving assistance, or reverse garage assistance.

34. The in-vacuum robotic device of aspect 28, wherein:

the sensor is optical and comprises a light source and a light detector, and

the light source is focused through the first through hole of the base plate and onto the front side of the reticle, and is configured to allow scattered light detection by the sensor.

35. The in-vacuum robotic device of aspect 34, wherein the light source is an infrared light source.

36. The in-vacuum robotic device of aspect 34, wherein the sensor further comprises one or more beam shaping optics.

37. The in-vacuum robotic device of aspect 28, further comprising:

a second through hole in the bottom plate; and

a second sensor disposed below the base plate, wherein the second sensor is configured to detect a second position of the reticle in the reticle exchange area through the second through-hole of the base plate during the reticle exchange process, wherein the second position of the reticle comprises a vertical distance between the front side of the reticle and a fixed plane of the sensor and a relative tilt angle between the front side of the reticle and the fixed plane of the sensor,

wherein the controller is coupled to the second sensor and configured to control a position of the clamp based on the second position of the reticle detected by the second sensor.

38. The in-vacuum robot of aspect 37, wherein the controller is configured to correct a vertical distance offset and a relative tilt angle offset between the front side of the reticle and a front side of the chuck in real time based on a comparison between the position of the reticle detected by the sensor and the second position of the reticle detected by the second sensor.

Although specific reference may be made in this text to the use of lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein may have other applications. Possible other applications include the manufacture of integrated optical systems, guidance and detection for magnetic domain memories, flat panel displays, Liquid Crystal Displays (LCDs), thin film magnetic heads, etc.

Although specific reference may be made in this text to embodiments of the disclosure in the context of lithographic apparatus, embodiments of the disclosure may be used in other apparatus. Embodiments of the present disclosure may form part of a mask inspection apparatus, a metrology apparatus, or any apparatus that measures or processes an object such as a wafer (or other substrate) or a mask (or other patterning device). These devices may be generally referred to as lithographic tools. These lithography tools may use vacuum conditions or ambient (non-vacuum) conditions.

Although specific reference may have been made in detail to the use of embodiments of the disclosure in the context of optical lithography, it will be understood that the disclosure is not limited to optical lithography, and may be used in other applications, such as imprint lithography, where the context allows.

It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings herein.

The above examples are illustrative, but not limiting, of embodiments of the disclosure. Other suitable modifications and adaptations of the various conditions and parameters normally encountered in the art and which would be apparent to one skilled in the relevant art are within the spirit and scope of the present disclosure.

While specific embodiments of the invention have been described above, it will be appreciated that the invention may be practiced otherwise than as described. The above description is intended to be illustrative and not restrictive. Thus, it will be apparent to one skilled in the art that modifications may be made to the invention as described without departing from the scope of the claims set out below.

It should be understood that what is intended to be used to interpret the claims is the detailed description section, not the summary and abstract sections. The summary and abstract sections may set forth one or more, but not all exemplary embodiments of the present disclosure as contemplated by the inventors, and are therefore not intended to limit the disclosure and the appended claims in any way.

The invention has been described above with the aid of functional building blocks illustrating the implementation of specific functions and relationships thereof. Boundaries of these functional components have been arbitrarily defined herein for convenience of description. Other boundaries may be defined so long as the specified functions and relationships thereof are appropriately performed.

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

The breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims (24)

1. A clamping device, comprising:

a clamp;

a sensor disposed on a front side of the clamp, wherein the sensor is configured to detect a position of a reticle in a reticle exchange area during a reticle exchange process, wherein the position of the reticle comprises a vertical distance between a rear side of the reticle and the front side of the clamp and a relative inclination between the rear side of the reticle and the front side of the clamp; and

a controller coupled to the sensor and configured to control a position of the clamp based on the position of the reticle detected by the sensor.

2. The clamp apparatus of claim 1, wherein the controller is configured to correct a vertical distance offset and a relative tilt angle offset between the backside of the reticle and the front side of the clamp in real time.

3. The clamp apparatus of claim 1, wherein the controller is configured to control a reticle stage to allow compliant movement of the clamp until the front side of the clamp and the back side of the reticle are in contact and coplanar.

4. The clamp apparatus of claim 1, wherein the controller is configured to reduce a contact force between the reticle and the clamp and minimize particle generation between the reticle and the clamp.

5. The clamping device of claim 1, wherein the controller is configured to:

moving a reticle stage at a first speed until the position of the reticle is detected by the sensor; and

moving the reticle stage at a second speed, the first speed being greater than the second speed.

6. The clamping apparatus of claim 1, wherein the sensor is capacitive and comprises a planar electrode.

7. The clamping device of claim 1, wherein:

the sensor is optical and comprises a light source and a light detector; and

the light source is directed at the backside of the reticle at an acute angle relative to the front side of the jig.

8. The clamp apparatus of claim 1, wherein the sensor is pressurized and comprises a barometer.

9. The clamp apparatus of claim 1, wherein the sensor comprises a plurality of sensor arrays.

10. A clamping device, comprising:

a clamp;

a sensor disposed on a front side of the clamp, wherein the sensor is configured to detect a force of the reticle in a reticle exchange area during a reticle exchange process, wherein the force of the reticle comprises a stress or strain from a backside of the reticle or the front side of the clamp; and

a controller coupled to the sensor and configured to control a position of the clamp based on the force of the reticle detected by the sensor.

11. The clamp apparatus of claim 10, wherein the controller is configured to correct in real time stress or strain from the backside of the reticle or the front side of the clamp.

12. The clamp apparatus of claim 10, wherein the controller is configured to control a reticle stage to allow compliant movement of the clamp until the front side of the clamp and the back side of the reticle are in contact and coplanar.

13. The clamping apparatus of claim 10, wherein the sensor is resistive and comprises a planar strain gauge.

14. The clamping device of claim 10, wherein the sensor is resistive and comprises a lithographically patterned resistor configured to change resistance in proportion to applied pressure.

15. A sheet apparatus, comprising:

a plate comprising a reticle exchange port;

a sensor disposed in the reticle exchange port, wherein the sensor is configured to detect a position of a reticle in a reticle exchange area during a reticle exchange process, wherein the position of the reticle comprises a vertical distance between a rear side of the reticle and a fixed plane of the sensor and a relative inclination between the rear side of the reticle and the fixed plane of the sensor; and

a controller coupled to the sensor and configured to control a position of a clamp based on the position of the reticle detected by the sensor.

16. The plate apparatus of claim 15, wherein the controller is configured to correct a vertical distance offset and a relative tilt angle offset between the backside of the reticle and a front side of the chuck in real time.

17. The plate apparatus of claim 15, wherein the controller is configured to control a reticle stage to allow compliant movement of the clamp until a front side of the clamp and the back side of the reticle are in contact and coplanar.

18. The plate apparatus of claim 15 wherein:

the sensor is optical and comprises a light source and a light detector, and

the light source is a projected light pattern and is configured to allow structured light stereo detection by the sensor.

19. The plate apparatus of claim 15, wherein said sensor is optical and comprises a confocal sensor configured to be time synchronized.

20. A sheet apparatus, comprising:

a plate comprising a reticle exchange port;

a sensor disposed on a backside of the plate and distal to the reticle exchange port, wherein the sensor is configured to calibrate a position of a reticle in a reticle exchange area based on a fixed plane of the sensor during a reticle exchange process, wherein the position of the reticle comprises a vertical distance between a backside of the reticle and the fixed plane of the sensor and a relative tilt angle between the backside of the reticle and the fixed plane of the sensor; and

a controller coupled to the sensor and configured to control a position of a clamp based on the position of the reticle detected by the sensor.

21. The plate apparatus of claim 20, wherein the controller is configured to correct a vertical distance offset and a relative tilt angle offset between the backside of the reticle and a front side of the chuck based on a vertical distance offset and a relative tilt angle offset between the backside of the reticle and the fixed plane of the sensor.

22. The plate apparatus of claim 20, wherein the sensor is configured to measure the backside of the reticle synchronously.

23. The plate apparatus of claim 22 wherein said sensor is capacitive and comprises a planar electrode.

24. The plate apparatus of claim 22 wherein said sensor array is optical and comprises one or more confocal sensors.

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