High-speed correction of uniformity drift

Abstract

Systems, apparatus and methods are provided for adjusting illumination slit uniformity in a lithographic apparatus. An exemplary method may include a radiation source illuminating a portion of a finger assembly with radiation. The exemplary method may further include a radiation detector receiving at least a portion of the radiation in response to illuminating the portion of the finger assembly. The exemplary method may further include a processor determining a change in a shape of the finger assembly based on the received radiation. The exemplary method may further include the processor generating a control signal configured to modify a position of the finger assembly based on the determined change in the shape of the finger assembly. Thereafter, the exemplary method may include the processor sending the control signal to a motion control system coupled to the finger assembly.

Description

Technical Field

[0001] Cross - reference to Related Applications

[0001] This application claims the priority of U.S. Application No. 63 / 142,581 filed on January 28, 2021 and U.S. Application No. 63 / 144,798 filed on February 2, 2021, which are hereby incorporated by reference in their entirety.

[0002]

[0002] The present disclosure relates to systems and methods for correcting illumination non - uniformity in lithography apparatuses and systems.

Background Art

[0003]

[0003] A lithography apparatus is a machine that applies a desired pattern to a substrate, usually to a target portion of the substrate. A lithography apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such a case, a patterning device, synonymously referred to as a mask or reticle, can be used to generate the circuit pattern to be formed on individual layers of the IC being formed. This pattern can be transferred to a target portion (e.g., including a part of one or several dies) on a substrate (e.g., a silicon wafer). The transfer of the pattern is usually performed by imaging onto a layer of radiation - sensitive material (e.g., resist) provided on the substrate. Generally, a single substrate includes a network of adjacent target portions to which patterns are sequentially applied. Conventional lithography apparatuses include so - called steppers, in which each target portion is irradiated by exposing the entire pattern to the target portion once, and scanners, in which each target portion is irradiated by scanning the pattern with a radiation beam in a given direction (the "scan" direction) while synchronously scanning the target portion parallel or antiparallel (e.g., opposite) to a given direction (the "scan" direction). It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.

[0004]

[0004] As semiconductor manufacturing processes continue to advance, the number of functional elements such as transistors per device has steadily increased over decades, while the dimensions of circuit elements have continuously decreased, following a trend commonly known as Moore's Law. To keep pace with Moore's Law, the semiconductor industry is pursuing technologies that enable the creation of even smaller features. Lithography equipment sometimes uses electromagnetic radiation to project patterns onto substrates. The wavelength of this radiation determines the minimum size of features that can be patterned onto the substrate. Common wavelengths currently in use are 365 nm (i-line), 248 nm, 193 nm, and 13.5 nm.

[0005]

[0005] Extreme ultraviolet (EUV) radiation (for example, electromagnetic radiation having wavelengths of about 50 nanometers (nm) or less (sometimes referred to as soft X-rays), including light with a wavelength of about 13.5 nm) may be used in or with a lithography apparatus to generate extremely small features in or on a substrate (e.g., a silicon wafer). A lithography apparatus using EUV radiation with wavelengths in the range of 4 nm to 20 nm (e.g., 6.7 nm or 13.5 nm) can form smaller features on a substrate compared to a lithography apparatus using radiation with a wavelength of, for example, 193 nm.

[0006]

[0006] Methods for generating EUV light include, but are not limited to, converting a material having elements with emission lines in the EUV region, such as xenon (Xe), lithium (Li), or tin (Sn), into a plasma state. For example, in one such method called laser-generated plasma (LPP), the plasma may be generated by irradiating a target material (which is synonymously referred to as fuel in relation to the LPP source), in the form of droplets, plates, tapes, streams, or clusters of the material, with an amplified light beam which may be called a drive laser. For this process, the plasma is generally generated in a sealed container (e.g., a vacuum chamber) and monitored using various types of metronome equipment.

[0007]

[0007] A lithography apparatus typically includes an illumination system that adjusts the radiation generated by a radiation source before it enters the patterning device. The illumination system may modify one or more properties of the radiation, such as polarization and / or illumination mode. The illumination system may include a uniformity correction system that corrects or reduces non-uniformity (e.g., intensity non-uniformity) present in the radiation. The uniformity correction device may employ an actuated finger assembly inserted at the edge of the radiation beam to correct for intensity variations. The spatial spread of illumination adjustable by the uniformity correction system depends, among other things, on the size of the finger assembly and the size of the actuated device used to move the finger assembly in the uniformity correction system. Modifying the finger parameters from a known fabrication design is not a trivial matter, because such modifications can lead to undesirable changes in one or more properties of the radiation beam.

[0008]

[0008] To achieve acceptable image quality in the patterning device and substrate, a controlled uniformity illumination beam is desirable. Typically, an illumination beam has a non-uniform intensity profile before it is reflected by or transmitted through the patterning device. At various stages of the lithography process, it is desirable that the illumination beam be controlled to achieve improved uniformity. Uniformity may refer to a constant intensity across the relevant cross-section of the illumination beam, but it may also refer to the ability to control the illumination to achieve selected uniformity parameters. The patterning device imparts a pattern to the radiating beam, which is then projected onto the substrate. The image quality of this projected beam is affected by the uniformity of the beam.

[0009]

[0009] Therefore, in order to maximize manufacturing capacity and yield, minimize manufacturing defects, and reduce the cost per device, it is desirable to control the illumination uniformity so that the lithography tool can perform the lithography process as efficiently as possible. [Overview of the project]

[0010]

[0010] This disclosure describes various aspects of systems, apparatus, and methods for adjusting the uniformity of illumination slits in a lithography apparatus.

[0011]

[0011] In some embodiments, the present disclosure describes a system. The system may include a radiation source configured to generate radiation and transmit the generated radiation toward a finger assembly. The system may further include a radiation detector configured to receive at least a portion of the transmitted radiation. The system may further include a processor configured to determine a change in the shape of the finger assembly based on the received radiation. The processor may further include a control signal configured to correct the position of the finger assembly based on the determined change in the shape of the finger assembly. The processor may further include a control signal that transmits to a motion control system coupled to the finger assembly.

[0012]

[0012] In some embodiments, the determined change in the shape of the finger assembly may include a change in the position of the optical edge of the fingertip based on the growth of the fingertip in response to exposure of the fingertip of the finger assembly to deep ultraviolet (DUV) radiation or extreme ultraviolet (EUV) radiation.

[0013]

[0013] In some embodiments, the radiation source may be configured to transmit radiation during wafer exchange operations of the lithography apparatus. In other embodiments, the radiation source may be configured to transmit radiation during wafer exposure operations of the lithography apparatus.

[0014]

[0014] In some embodiments, the generated radiation may include a laser curtain, and the radiation detector may be configured to receive at least a portion of the radiation transmitted in response to the irradiation of a portion of the finger assembly by the laser curtain. In some embodiments, the portion of the finger assembly may include the mechanical edge of the finger tip of the finger assembly, which is spaced apart from the optical edge of the finger tip of the finger assembly.

[0015]

[0015] In some embodiments, the received radiation may include radiation reflected from the surface of the fingertip in response to the irradiation of the surface of the fingertip of the finger assembly by the transmitted radiation.

[0016]

[0016] In some embodiments, the processor may be further configured to measure changes in the position of reference marks disposed on the finger assembly based on the received radiation. In some embodiments, the processor may be further configured to determine changes in the shape of the finger assembly based on the measured changes in the position of the reference marks. In some embodiments, the reference marks may be affixed to areas of multilayer mirror material disposed on the finger tips of the finger assembly. For example, in such embodiments, the radiation detector may be configured to sense the reflective portion of chemical beam EUV light used during the wafer exposure operation of the lithography apparatus.

[0017]

[0017] In some embodiments, the present disclosure describes an apparatus. The apparatus may include a finger assembly. The finger assembly may include a finger body, a finger tip, a multilayer mirror material disposed on the surface of the finger tip, and a set of reference marks affixed to a region of the multilayer mirror material. In some embodiments, the set of reference marks may include two or more reference marks. In some embodiments, the multilayer mirror material may be configured to reflect DUV or EUV radiation toward a radiation detector during the exposure operation of the lithography apparatus. In some embodiments, the multilayer mirror material may contain molybdenum.

[0018]

[0018] In some embodiments, the present disclosure describes a method for adjusting the uniformity of the illumination slit in a lithography apparatus. The method may include a radiation source irradiating a portion of a finger assembly with radiation. The method may further include a radiation detector receiving at least a portion of the radiation in response to the irradiation of the portion of the finger assembly. The method may further include a processor determining a change in the shape of the finger assembly based on the received radiation. The method may further include the processor generating a control signal configured to correct the position of the finger assembly based on the determined change in the shape of the finger assembly. The method may further include the processor transmitting the control signal to a motion control system coupled to the finger assembly.

[0019]

[0019] In some embodiments, determining changes in the shape of the finger assembly may involve the processor determining changes in the position of the optical edges of the fingertips based on the growth of the fingertips in response to exposure of the fingertips of the finger assembly to DUV or EUV radiation.

[0020]

[0020] In some embodiments, irradiating a portion of the finger assembly may include the radiation source irradiating a portion of the finger assembly with radiation during a wafer change operation of the lithography apparatus. In other embodiments, irradiating a portion of the finger assembly may include the radiation source irradiating a portion of the finger assembly with radiation during a wafer exposure operation of the lithography apparatus.

[0021]

[0021] In some embodiments, the radiation may include a laser curtain, and receiving at least a portion of the radiation may include the radiation detector receiving at least a portion of the radiation transmitted in response to the laser curtain illuminating a portion of the finger assembly. In some embodiments, the portion of the finger assembly may include the mechanical edge of the fingertip of the finger assembly, which is spaced apart from the optical edge of the fingertip of the finger assembly.

[0022]

[0022] In some embodiments, receiving at least a portion of the radiation may include the radiation detector receiving radiation reflected from the surface of the fingertip in response to the surface of the fingertip of the finger assembly being irradiated with radiation.

[0023]

[0023] In some embodiments, determining a change in the shape of the finger assembly may include the processor measuring a change in the position of a reference mark placed on the finger assembly based on the received radiation. In some embodiments, determining a change in the shape of the finger assembly may further include the processor determining a change in the shape of the finger assembly based on the measured change in the position of the reference mark. In some embodiments, the reference mark is affixed to a region of multilayer mirror material placed on the finger tip of the finger assembly. For example in such embodiments, the method may include the radiation detector sensing the reflective portion of chemical beam EUV light used during the wafer exposure operation of the lithography apparatus.

[0024]

[0024] Further features and various aspects of the structure and operation are described in detail below with reference to the accompanying drawings. Note that the present disclosure is not limited to the specific aspects described herein. Such aspects are presented herein for illustrative purposes only. Further aspects will be apparent to those skilled in the art based on the teachings contained herein.

Brief Description of the Drawings

[0025]

[0025] The accompanying drawings, which are incorporated herein and constitute a part of this specification, further serve to illustrate the present disclosure, explain the principles of the aspects of this disclosure together with the description, and enable those skilled in the art to implement and use the aspects of this disclosure.

[0026] [Figure 1A]

[0026] It is a schematic diagram of an exemplary reflective lithography apparatus according to some aspects of the present disclosure. [Figure 1B]

[0027] It is a schematic diagram of an exemplary transmissive lithography apparatus according to some aspects of the present disclosure. [Figure 2]

[0028] It is a more detailed schematic diagram of the reflective lithography apparatus shown in FIG. 1A according to some aspects of the present disclosure. [Figure 3]

[0029] It is a schematic diagram of an exemplary lithography cell according to some aspects of the present disclosure. [Figure 4]

[0030] It is a schematic diagram of an exemplary radiation source for an exemplary reflective lithography apparatus according to some aspects of the present disclosure. [Figure 5A]

[0031] It is a schematic diagram of an exemplary illumination uniformity correction system according to some aspects of the present disclosure. [Figure 5B]

[0031] It is a schematic diagram of an exemplary illumination uniformity correction system according to some aspects of the present disclosure. [Figure 6]

[0032] It is a schematic diagram of an exemplary illumination uniformity correction system according to some aspects of the present disclosure. [Figure 7]

[0033] This is a schematic diagram of another exemplary illumination uniformity correction system relating to some aspects of the present disclosure. [Figure 8]

[0034] This is a schematic diagram of another exemplary illumination uniformity correction system relating to some aspects of the present disclosure. [Figure 9]

[0035] This is a schematic diagram of an exemplary set of reference marks relating to several aspects of this disclosure. [Figure 10]

[0036] This is a schematic diagram of another exemplary illumination uniformity correction system relating to some aspects of the present disclosure. [Figure 11]

[0037] This is an exemplary method for adjusting the uniformity of the illumination slit in a lithography apparatus, relating to some aspects or parts thereof of the present disclosure. [Figure 12]

[0038] This is an exemplary computer system for implementing some aspects or parts thereof of the present disclosure.

[0027]

[0039] The features and merits of this disclosure will become more apparent from the detailed description below, along with the drawings, in which similar reference numerals identify corresponding elements throughout. In the drawings, unless otherwise stated, similar reference numerals generally indicate identical, functionally similar, and / or structurally similar elements. More generally, one or more leftmost digits of a reference numeral identify the drawing in which that reference numeral first appears. Unless otherwise stated, the drawings provided throughout this disclosure should not be construed as drawings to a fixed scale. [Modes for carrying out the invention]

[0028]

[0040] This specification discloses one or more embodiments incorporating the features of the present disclosure. The one or more disclosed embodiments are merely illustrative of the present disclosure. The scope of the present disclosure is not limited to the one or more disclosed embodiments. The breadth and scope of the present disclosure are defined by the claims and equivalents appended to this specification.

[0029]

[0041] The one or more embodiments described herein, and any references to “one embodiment,” “a certain embodiment,” or “exemplary embodiment” within this specification, indicate that one or more embodiments described may include certain features, structures, or characteristics, but not all embodiments may necessarily include those features, structures, or characteristics. Furthermore, such expressions do not necessarily refer to the same embodiment. In addition, if certain features, structures, or characteristics are described in relation to a particular embodiment, it is understood that, whether explicitly stated or not, the influence of such features, structures, or characteristics in relation to other embodiments is within the scope of the knowledge of those skilled in the art.

[0030]

[0042] Spatially relative terms such as "beneath," "below," "lower," "above," "on," and "upper" may be used herein to facilitate the description of the relationship between one element or function and one or more other elements or functions, as shown in the figures. Spatially relative terms are intended to encompass various orientations of the device in use or operation, in addition to the orientation shown in the figures. The device may be in other orientations (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly.

[0031]

[0043] As used herein, the term “approximately” indicates a value of a given quantity that may vary based on a particular technique. Based on a particular technique, the term “approximately” may indicate a value of a given quantity that varies, for example, within a range of 10 to 30% of the value (e.g., ±10%, ±20%, or ±30% of the value).

[0032] overview

[0044] An exemplary illumination uniformity correction system called "Unicom" can adjust slit uniformity in the cross-scan direction by attenuating illumination "hot spots" by introducing a finger assembly, i.e., a set of "finger" elements, into the illumination slit. Unicom may be configured to operate in either of two "modes": (1) a first mode involving wafer-by-wafer uniformity correction to compensate for illumination effects, and (2) a second mode in which slit uniformity is modified die-by-die to compensate for wafer and process effects, with uniformity correction changing in parallel with the stepping die. When incident light (e.g., EUV radiation) heats the Unicom finger tip, the Unicom position measurement and the unmeasured distance from the finger tip change, which can cause drift in slit uniformity. For example, as power increases in a lithography apparatus, the expected critical dimension (CD) effect of uniformity drift can increase from approximately 0.06 nm (below 600 W power) to approximately 0.1 nm (above 600 W power) or more. The CD effect may be approximately equal to 0.3 times the uniformity ratio. CD uniformity (CDU) requirements may range from approximately 0.7 nm to 1.2 nm. In some cases, slit uniformity drift may not be compensated for.

[0033]

[0045] In one example, slit uniformity drift is measured and corrected approximately every 900 seconds, or in another example, once per wafer lot, potentially resulting in an uncorrectable CD effect. In some embodiments, the CD effect may be reduced by performing more frequent measurements. On the other hand, each uniformity refresh (UR) measurement takes approximately 2 seconds and may involve the use of sensors on the wafer stage. As a result, these measurements may not be performed in parallel with wafer stage chuck changes. Furthermore, at least two additional uniformity refresh measurements may be required in the first lot to reduce slit uniformity drift by half, extending the lot time for 25 wafers from approximately 900 seconds to approximately 904 seconds, which can reduce overall machine throughput.

[0034]

[0046] In response to this, several aspects of the present disclosure may provide the use of a reference measurement method close to the fingertip to compensate for the uncorrected thermal drift of the Unicom. By periodically measuring one reference plane of the fingertip, the actual fingertip growth may not yield throughput benefits as it is measured periodically without the need for a sensor on the wafer stage. To measure and estimate fingertip growth with respect to a position sensor such as an encoder scale, several aspects of the present disclosure may provide measuring the change in distance of one or more reference points on or associated with the Unicom fingertip to an encoder index pulse. In some aspects, the original distance from the Unicom fingertip to the encoder reference mark may be periodically calibrated or measured once during Unicom construction.

[0035]

[0047] In some embodiments, the disclosure can provide a fingertip sensor comprising a single beam that spans all finger assemblies, minimizing the number of sensors. In such embodiments, each finger may have to travel its complete travel path until the fingertip position is measured. For example, each finger may travel its complete travel path in approximately 200 ms. As a result, measuring all 28 finger assemblies may take approximately 6 seconds, and therefore the measurement may be performed in parallel with wafer changes.

[0036]

[0048] In some embodiments, algorithms may be used to maximize the number of finger assemblies measured between batches, because the wafer chuck change time is approximately 2.5 seconds and the available “shadow time” for Unicom movement is approximately 0.43 seconds. For example, some embodiments of the present disclosure may measure only the furthest inserted finger assemblies and the least inserted finger assemblies and interpolate the measurement results. Additionally or alternatively, some embodiments of the present disclosure may include etching a mark onto the finger tip (or creating a new surface on the finger tip to make this mark) and measuring the displacement of this mark as a function of finger thermal growth.

[0037]

[0049] In some embodiments, fingertip growth may be proportional to the change in the distance of a selected reference point on the fingertip assembly relative to the encoder index. In some embodiments, measurement and adjustment may be performed wafer-wise or die-wise. In some embodiments, "room temperature" or the reference distance from the fingertip to the encoder may be calibrated periodically or only once during the construction of the fingertip assembly. In some embodiments, fingertip growth of approximately 8 μm or less may be detected.

[0038]

[0050] In some embodiments, the Disclosure provides, for example, that a radiation source irradiates a portion of a finger assembly with radiation; a radiation detector receives at least a portion of the radiation in response to the irradiation of the portion of the finger assembly; a processor determines a change in the shape of the finger assembly based on the received radiation; the processor generates a control signal configured to correct the position of the finger assembly based on the determined change in the shape of the finger assembly; and the processor adjusts the uniformity of the illumination slit in a lithography apparatus by transmitting the control signal to a motion control system coupled to the finger assembly.

[0039]

[0051] There are many exemplary embodiments of the systems, apparatus, methods, and computer program products disclosed herein. For example, an embodiment of this disclosure provides reducing CD drift and CDU effects from Unicom from about 0.1 nm or greater (e.g., for all tool generations with source power greater than about 350 W) to less than about 0.06 nm. A 40 percent reduction in CDU effect from about 0.1 nm to about 0.06 nm can be significant when the CDU requirement may be less than or equal to about 0.6 nm. In another embodiment, there is virtually no throughput effect in reducing CD drift because an embodiment of this disclosure does not require a sensor on the wafer stage. In yet another embodiment, an embodiment of this disclosure does not require an external sensor (e.g., a high-precision pressure sensor) on Unicom. In yet another embodiment, an embodiment of this disclosure does not require prior knowledge of finger assembly insertion.

[0040]

[0052] However, before describing such embodiments in more detail, it is useful to provide exemplary environments in which embodiments of this disclosure may be implemented.

[0041] Exemplary Lithography System

[0053] Figures 1A and 1B are schematic diagrams of a lithography apparatus 100 and a lithography apparatus 100', respectively, in which embodiments of the present disclosure may be implemented. As shown in Figures 1A and 1B, the lithography apparatuses 100 and 100' are shown from a viewpoint (e.g., a side view) perpendicular to the XZ plane (e.g., the X-axis points to the right, the Z-axis points upward, and the Y-axis points inward from the viewer), and the patterning device MA and substrate W are shown from another viewpoint (e.g., a top view) perpendicular to the XY plane (e.g., the X-axis points to the right, the Y-axis points upward, and the Z-axis points outward from the viewer).

[0042]

[0054] In some embodiments, the lithography apparatus 100 and / or lithography apparatus 100' may include one or more substrate holders, such as a substrate table WT (e.g., a wafer table), configured to support a patterning device MA (e.g., a mask, reticle, or dynamic patterning device) and connected to a first positioner PM configured to precisely position the patterning device MA; and a projection system PS (e.g., a refractive projection lens system), configured to project the pattern applied to the patterning device MA onto a target portion C of the substrate W (e.g., a portion containing one or more dies). In lithography apparatus 100, the patterning device MA and projection system PS are reflective. In lithography apparatus 100', the patterning device MA and projection system PS are transmissive.

[0043]

[0055] In some embodiments, during operation, the illumination system IL can receive a radiated beam from the radiation source SO (e.g., via the beam delivery system BD shown in Figure 1B). The illumination system IL may include various types of optical structures, such as refraction, reflection, reflex, magnetic, electromagnetic, electrostatic, and other types of optical components, or any combination thereof, for inducing, shaping, or controlling the radiation. In some embodiments, the illumination system IL may be configured to adjust the radiated beam B in the plane of the patterning device MA so that it has a desired spatial and angular intensity distribution in cross-section.

[0044]

[0056] In some embodiments, the support structure MT can hold the patterning device MA in a manner that depends on the orientation of the patterning device MA relative to a reference frame, the design of at least one of the lithography apparatus 100 and 100', and other conditions such as whether the patterning device MA is held in a vacuum environment. The support structure MT can use mechanical, vacuum, electrostatic, or other clamping techniques to hold the patterning device MA. The support structure MT may be, for example, a frame or a table, and may be fixed or movable as needed. By using sensors, the support structure MT can ensure that the patterning device MA is in a desired position relative to, for example, a projection system PS.

[0045]

[0057] The term “patterning device” (MA) is broadly interpreted to refer to any device that can be used to impart a pattern to a cross-section of a radiation beam B, such as for creating a pattern on a target portion C of a substrate W. The pattern imparted to the radiation beam B may correspond to a specific functional layer within the device, which is created on the target portion C to form an integrated circuit.

[0046]

[0058] In some embodiments, the patterning device MA may be transmissive (as in the case of lithography apparatus 100' in Figure 1B) or reflective (as in the case of lithography apparatus 100 in Figure 1A). The patterning device MA may include various structures such as a reticle, a mask, a programmable mirror array, a programmable LCD panel, other suitable structures, or a combination thereof. The mask may include mask types such as binary, Levenson (alternating) phase shift, or halftone (attenuated) phase shift, and various hybrid mask types. In one example, the programmable mirror array may include a matrix arrangement of small mirrors, each of which may be individually tilted to reflect the incident radiation beam in various directions. The tilted mirrors can impart a pattern to the radiation beam B, which is then reflected by the matrix of small mirrors.

[0047]

[0059] The term “projection system” PS is broadly interpreted and may encompass any type of projection system, including refraction, reflection, reflex-refractivity, magnetic, anamorphic, electromagnetic, and electrostatic-optical systems, or any combination thereof, depending on the exposure radiation used and / or other factors such as the use of immersion liquid (e.g., on a substrate W) or vacuum. A vacuum environment may be used for EUV or electron beam radiation because other gases may excessively absorb radiation or electrons. Therefore, a vacuum environment may be provided throughout the beam path using vacuum walls and vacuum pumps. In addition, the use of the term “projection lens” herein may, in some embodiments, be interpreted as synonymous with the more general term “projection system” PS.

[0048]

[0060] In some embodiments, the lithography apparatus 100 and / or lithography apparatus 100' may be of a type having two or more substrate tables WT and / or two or more mask tables (e.g., a “dual stage”). In such a “multistage” machine, additional substrate tables WT can be used in parallel, or preparation steps can be performed on one or more tables while one or more other substrate tables WT are being used for exposure. In one example, the preparation steps for the subsequent exposure of a substrate W may be performed on a substrate W located on one of the substrate tables WT while another substrate W located on another substrate table WT is being used to expose a pattern on another substrate W. In some embodiments, the additional tables may not be substrate tables WT.

[0049]

[0061] In some embodiments, in addition to the substrate table WT, the lithography apparatus 100 and / or lithography apparatus 100' may include a measurement stage. The measurement stage may be positioned to hold sensors. The sensors may be positioned to measure the characteristics of the projection system PS, the characteristics of the radiation beam B, or both. In some embodiments, the measurement stage may hold multiple sensors. In some embodiments, the measurement stage may move directly below the projection system PS when the substrate table WT is away from the projection system PS.

[0050]

[0062] In some embodiments, the lithography apparatus 100 and / or lithography apparatus 100' may be of a type in which at least a portion of the substrate may be covered with a liquid having a relatively high refractive index (e.g., water) to fill the space between the projection system PS and the substrate W. The immersion liquid may also be provided in other spaces of the lithography apparatus, such as between the patterning device MA and the projection system PS. Immersion techniques provide an increase in the numerical aperture of the projection system. As used herein, the term “immersion” does not mean that a structure such as a substrate must be submerged in the liquid, but simply that the liquid is located between the projection system and the substrate during exposure. Various immersion techniques are described herein by reference in whole in U.S. Patent No. 6,952,253, “LITHOGRAPHIC APPARATUS AND DEVICE MANUFACTURING METHOD,” issued 4 October 2005.

[0051]

[0063] Referring to Figures 1A and 1B, the illumination system IL receives the radiated beam B from the radiated source SO. The radiated source SO and the lithography apparatus 100 or 100' may be separate physical entities, for example, if the radiated source SO is an excimer laser. In such a case, the radiated source SO is not considered to constitute part of the lithography apparatus 100 or 100', and the radiated beam B passes from the radiated source SO to the illumination system IL using a beam delivery system BD (e.g., shown in Figure 1B) which includes, for example, appropriate guide mirrors and / or beam expanders. In other cases, the radiated source SO may be an integral part of the lithography apparatus 100 or 100', for example, if the radiated source SO is a mercury lamp. The radiated source SO and the illuminator IL may, as appropriate, be referred to as the radiated system together with the beam delivery system BD.

[0052]

[0064] In some embodiments, the illumination system IL may include an adjuster AD for adjusting the angular intensity distribution of the radiated beam. Generally, at least the outer and / or inner radial ranges of the intensity distribution within the pupil plane of the illuminator (usually referred to as "σ-outer" and "σ-inner," respectively) can be adjusted. In addition, the illumination system IL may include various other components such as an integrator IN and a radiated collector CO (e.g., a capacitor or collector system). In some embodiments, the illumination system IL can be used to adjust the radiated beam B to have a desired uniformity and intensity distribution in its cross-section.

[0053]

[0065] Referring to Figure 1A, during operation, the radiant beam B may be incident on a patterning device MA (e.g., a mask, reticle, programmable mirror array, programmable LCD panel, any other suitable structure, or a combination thereof) which may be held on a support structure MT (e.g., a mask table), and may be patterned by a pattern (e.g., a design layout) present on the patterning device MA. In the lithography apparatus 100, the radiant beam B may be reflected from the patterning device MA. After traversing the patterning device MA (e.g., after being reflected from the patterning device MA), the radiant beam B may pass through a projection system PS which can focus the radiant beam B onto a target portion C of the substrate W or onto a sensor positioned on the stage.

[0054]

[0066] In some embodiments, a second positioner PW and a position sensor IFD2 (e.g., an interference device, a linear encoder, or a capacitance sensor) can be used to precisely move the substrate table WT to position various target portions C in the path of the radiation beam B, for example. Similarly, a first positioner PM and another position sensor IFD1 (e.g., an interference device, a linear encoder, or a capacitance sensor) can be used to precisely position the patterning device MA relative to the path of the radiation beam B.

[0055]

[0067] In some embodiments, the patterning device MA and the substrate W may be aligned using mask alignment marks M1 and M2 and substrate alignment marks P1 and P2. Figures 1A and 1B show the substrate alignment marks P1 and P2 occupying dedicated target portions, although the substrate alignment marks P1 and P2 may be located in the space between target portions. When the substrate alignment marks P1 and P2 are located between target portions C, they are known as scribe line alignment marks. The substrate alignment marks P1 and P2 may also be placed in the target portion C area as in-die marks. These in-die marks may also be used, for example, as metrology marks for overlay measurements.

[0056]

[0068] In some embodiments, for illustrative purposes only and not limiting, one or more of the figures herein may utilize a Cartesian coordinate system. A Cartesian coordinate system includes three axes: the X, Y, and Z axes. Each of the three axes is orthogonal to the other two axes (for example, the X axis is orthogonal to the Y and Z axes, the Y axis is orthogonal to the X and Z axes, and the Z axis is orthogonal to the X and Y axes). A rotation about the X axis is referred to as an Rx rotation. A rotation about the Y axis is referred to as a Ry rotation. A rotation about the Z axis is referred to as an Rz rotation. In some embodiments, the X and Y axes define the horizontal plane, while the Z axis is perpendicular. In some embodiments, the orientation of the Cartesian coordinate system may differ, for example, such that the Z axis has a component aligned with the horizontal plane. In some embodiments, other coordinate systems, such as cylindrical coordinates, may be used.

[0057]

[0069] Referring to Figure 1B, the radiation beam B is incident on a patterning device MA held by a support structure MT, and a pattern is formed by the patterning device MA. After traversing the patterning device MA, the radiation beam B passes through a projection system PS, which focuses the beam onto a target portion C of the substrate W. In some embodiments, the projection system PS may have a pupil conjugate to the pupil of an illumination system. In some embodiments, a portion of the radiation may originate from the intensity distribution in the pupil of the illumination system, traverse the mask pattern MP without being affected by diffraction, and generate an image of the intensity distribution in the pupil of the illumination system.

[0058]

[0070] The projection system PS projects an image MP' of a mask pattern MP onto a resist layer coated on a substrate W, such that the image MP' is formed by a diffracted beam generated from the mask pattern MP by radiation from an intensity distribution. For example, the mask pattern MP may include an array of lines and spaces. Diffraction of radiation different from zero-order diffraction in the array generates a diffracted beam whose direction is redirected by a change in direction perpendicular to the lines. The reflected light (e.g., the zero-order diffracted beam) traverses the pattern without a change in propagation direction. The zero-order diffracted beam reaches the pupil conjugate by traversing the upper lens or upper lens group of the projection system PS, which is upstream of the pupil conjugate of the projection system PS. The portion of the intensity distribution associated with the zero-order diffracted beam that lies in the plane of the pupil conjugate is an image of the intensity distribution in the pupil of the illumination system IL. In some embodiments, the aperture device may be located in or substantially in the plane containing the pupil conjugate of the projection system PS.

[0059]

[0071] The projection system PS is positioned to capture not only the zero-order diffracted beam but also the first-order or higher-order diffracted beams (not shown) using lenses or lens groups. In some embodiments, the resolution-enhancing effect of dipole illumination can be utilized by using dipole illumination to image a line pattern extending perpendicular to the line. For example, the first-order diffracted beam interferes with the corresponding zero-order diffracted beam at the height of the substrate W to produce an image of the mask pattern MP with the highest possible resolution and process window (e.g., usable depth of field combined with allowable exposure dose deviation). In some embodiments, astigmatism can be reduced by providing a radiating pole (not shown) in the opposite quadrant of the illumination system pupil. Furthermore, in some embodiments, astigmatism can be reduced by blocking the zero-order beam in the pupil conjugate of the projection system PS in relation to the radiating pole in the opposite quadrant. This is described in detail in U.S. Patent No. 7,511,799, issued on March 31, 2009, entitled “LITHOGRAPHIC PROJECTION APPARATUS AND A DEVICE MANUFACTURING METHOD,” which is incorporated herein by reference in its entirety.

[0060]

[0072] In some embodiments, using a second positioner PW and a position measuring system PMS (including, for example, position sensors such as an interference device, a linear encoder, or a capacitance sensor), the substrate table WT can be precisely moved to position various target portions C at focused and aligned positions along the path of the radiation beam B. Similarly, using a first positioner PM and another position sensor (e.g., an interference device, a linear encoder, or a capacitance sensor) (not shown in Figure 1B), the patterning device MA can be precisely positioned relative to the path of the radiation beam B (e.g., after or during a machine search of the mask library). The patterning device MA and the substrate W can be aligned using mask alignment marks M1 and M2 and substrate alignment marks P1 and P2.

[0061]

[0073] Generally, the movement of the support structure MT can be achieved using long-stroke positioners (coarse positioning) and short-stroke positioners (fine positioning) that constitute part of the first positioner PM. Similarly, the movement of the substrate table WT can be achieved using long-stroke positioners and short-stroke positioners that form part of the second positioner PW. In the case of a stepper (as opposed to a scanner), the support structure MT may be connected only to short-stroke actuators or may be fixed. The patterning device MA and substrate W may be aligned using mask alignment marks M1 and M2, as well as substrate alignment marks P1 and P2. The substrate alignment marks (as illustrated) occupy dedicated target portions but may be located in the space between target portions (e.g., scribe line alignment marks). Similarly, in situations where two or more dies are provided on the patterning device MA, the mask alignment marks M1 and M2 may be located between the dies.

[0062]

[0074] The support structure MT and patterning device MA may reside within a vacuum chamber V, where an in-vacuum robot can be used to move the patterning device, such as a mask, in and out of the vacuum chamber. Alternatively, if the support structure MT and patterning device MA are outside the vacuum chamber, an out-of-vacuum robot similar to an in-vacuum robot can be used for various transport operations. In some examples, both the in-vacuum and out-of-vacuum robots need to be calibrated for the smooth transport of the payload (e.g., a mask) to a fixed motion mount at a transport station.

[0063]

[0075] In some embodiments, the lithography apparatuses 100 and 100' may be used in at least one of the following modes:

[0064]

[0076] 1. In step mode, the support structure MT and substrate table WT are kept essentially stationary (e.g., single static exposure) while the entire pattern applied to the radiation beam B is projected onto the target portion C at once. Next, the substrate table WT is shifted in the X and / or Y directions so that different target portions C can be exposed.

[0065]

[0077] 2. In scan mode, the support structure MT and substrate table WT are scanned synchronously (e.g., single dynamic exposure) while the pattern applied to the radiation beam B is projected onto the target portion C. The speed and direction of the substrate table WT relative to the support structure MT (e.g., mask table) may be determined by the scaling (reduction) and image inversion characteristics of the projection system PS.

[0066]

[0078] 3. In another mode, the support structure MT is kept substantially stationary while holding the programmable patterning device MA, and the substrate table WT is moved or scanned while the pattern applied to the radiation beam B is projected onto the target portion C. A pulsed radiation source SO may be used, and the programmable patterning device is updated as needed between consecutive radiation pulses after each movement of the substrate table WT or during scanning. This mode of operation can be readily applied to maskless lithography utilizing a programmable patterning device MA such as a programmable mirror array.

[0067]

[0079] In some embodiments, the lithography apparatuses 100 and 100' may use the above-described modes of use or combinations and / or variations of completely different modes of use.

[0068]

[0080] In some embodiments, as shown in Figure 1A, the lithography apparatus 100 may include an EUV source configured to generate an EUV radiation beam B for EUV lithography. Generally, the EUV source may be configured in a radiation source SO, and the corresponding illumination system IL may be configured to adjust the EUV radiation beam B of the EUV source.

[0069]

[0081] Figure 2 shows the lithography apparatus 100 in more detail, including the radiation source SO (e.g., source collector), illumination system IL, and projection system PS. As shown in Figure 2, the lithography apparatus 100 is shown from a viewpoint (e.g., a side view) perpendicular to the XZ plane (e.g., the X axis points to the right and the Z axis points upward).

[0070]

[0082] The radiation source SO is constructed and positioned to maintain a vacuum environment within a closed structure 220. The radiation source SO comprises a source chamber 211 and a collector chamber 212 and is configured to generate and transmit EUV radiation. The EUV radiation may be generated by a gas or vapor, such as xenon (Xe) gas, lithium (Li) vapor, or tin (Sn) vapor, which generates an EUV emitting plasma 210 to emit radiation in the EUV region of the electromagnetic spectrum. At least partially ionized EUV emitting plasma 210 may be generated, for example, by a discharge or a laser beam. For efficient radiation generation, a partial pressure of Xe gas, Li vapor, Sn vapor, or any other suitable gas or vapor can be used, for example, about 10.0 Pascals (Pa). In some embodiments, an excited tin plasma is provided to generate EUV radiation.

[0071]

[0083] Radiation emitted by the EUV emission plasma 210 passes from the source chamber 211 into the collector chamber 212 via an optional gas barrier or contaminant trap 230 (for example, also referred to as a contaminant barrier or foil trap), the gas barrier or contaminant trap 230 located at or after the opening of the source chamber 211. The contaminant trap 230 may include a channel structure. The contaminant trap 230 may also include a gas barrier or a combination of a gas barrier and a channel structure. The contaminant trap 230 further described herein includes at least a channel structure.

[0072]

[0084] The collector chamber 212 may contain a radiation collector CO (e.g., a capacitor or collector system), which may be a so-called oblique incidence collector. The radiation collector CO has an upstream radiation collector surface 251 and a downstream radiation collector surface 252. Radiation crossing the radiation collector CO may be reflected by a grating spectral filter 240 and focused to a virtual source point IF. The virtual source point IF is generally referred to as an intermediate focus, and the source collector apparatus is positioned such that the virtual source point IF is located at or near the aperture 219 of the closed structure 220. The virtual source point IF is an image of the EUV radiation-emitting plasma 210. The grating spectral filter 240 may be used to suppress infrared (IR) radiation.

[0073]

[0085] Next, the radiation crosses the illumination system IL, which may include a faceted field mirror device 222 and a faceted pupil mirror device 224, positioned to provide a desired angular distribution of the radiation beam 221 and a desired uniformity of radiation intensity in the patterning device MA. Upon reflection of the radiation beam 221 in the patterning device MA held by the support structure MT, a patterned beam 226 is formed, and the patterned beam 226 is imaged onto a substrate W held by a wafer stage or substrate table WT by a projection system PS via reflective elements 228, 229.

[0074]

[0086] The illumination system IL and projection system PS may generally contain more elements than those shown. Optionally, the grating spectral filter 240 may be present depending on the type of lithography apparatus. Furthermore, there may be more mirrors than shown in Figure 2. For example, there may be 1 to 6 more reflective elements in the projection system PS than shown in Figure 2.

[0075]

[0087] As shown in Figure 2, the radiation collector CO is depicted as a nested collector with oblique incidence reflectors 253, 254, and 255, as just one example of a collector (or collector mirror). The oblique incidence reflectors 253, 254, and 255 are arranged axially symmetrically with respect to the optical axis O, and this type of radiation collector CO is preferably used in combination with a discharge-generated plasma (DPP) source.

[0076] Exemplary lithography cells

[0088] Figure 3 shows a lithography cell 300, sometimes referred to as a lithocell or cluster. As shown in Figure 3, the lithography cell 300 is shown from a viewpoint perpendicular to the XY plane (for example, a top view) (e.g., the X-axis points to the right and the Y-axis points upward).

[0077]

[0089] The lithography apparatus 100 or 100' may constitute part of the lithography cell 300. The lithography cell 300 may also include one or more devices for performing pre-exposure and post-exposure processes on the substrate. For example, these devices may include a spin coater SC for depositing a resist layer, a developer DE for developing the exposed resist, a cooling plate CH, and a bake plate BK. A substrate handler RO (e.g., a robot) picks up the substrates from input / output ports I / O1 and I / O2, moves them between various process devices, and transports them to the loading bay LB of the lithography apparatus 100 or 100'. These devices, often collectively referred to as the track, are under the control of a track control unit TCU, which in turn is controlled by a monitoring and control system SCS, which also controls the lithography apparatus via a lithography control unit LACU. Thus, various devices can be operated to maximize throughput and processing efficiency.

[0078] Exemplary radiation source

[0090] An example of a radiation source SO for an exemplary reflective lithography apparatus (e.g., lithography apparatus 100 in Figure 1A) is shown in Figure 4. As shown in Figure 4, the radiation source SO is shown from a viewpoint perpendicular to the XY plane below (e.g., a top view).

[0079]

[0091] The radiation source SO shown in Figure 4 is of a type that may be called a laser-generated plasma (LPP) source. A laser system 401, which may include, for example, a carbon dioxide (CO2) laser, is arranged to impart energy to one or more individual tin (Sn) droplets or other fuel targets 403' provided by a fuel target generator 403 (e.g., a fuel ejector, droplet generator) via one or more laser beams 402. In some embodiments, the laser system 401 may be a pulsed continuous-wave or quasi-continuous-wave laser, or may operate like a pulsed continuous-wave or quasi-continuous-wave laser. The trajectory of the fuel targets 403' (e.g., droplets) emitted from the fuel target generator 403 may be parallel to the X-axis. In some embodiments, one or more laser beams 402 propagate in a direction parallel to the Y-axis, perpendicular to the X-axis. The Z-axis is perpendicular to both the X and Y axes and generally extends towards (or towards) the back of the plane of paper, although other configurations are used in other embodiments. In some embodiments, the laser beam 402 can propagate in a direction other than parallel to the Y-axis (for example, in a direction other than perpendicular to the X-axis direction of the trajectory of the fuel target 403').

[0080]

[0092] In some embodiments, one or more laser beams 402 may include a pre-pulsed laser beam and a main-pulsed laser beam. In such embodiments, the laser system 401 may be configured to irradiate each of the fuel targets 403' with the pre-pulsed laser beam to generate a modified fuel target. The laser system 401 may further be configured to irradiate each of the modified fuel targets with the main-pulsed laser beam to generate a plasma 407.

[0081]

[0093] Although the following description refers to tin, any suitable target material can be used. The target material may be, for example, liquid, or it may be, for example, a metal or alloy. The fuel target generator 403 may include a nozzle configured to direct tin, for example, in the form of fuel targets 403' (e.g., individual droplets) along a trajectory into the plasma-forming region 404. Throughout the remainder of the description, references to “fuel,” “fuel target,” or “fuel droplets” should be understood as referring to the target material (e.g., droplets) emitted by the fuel target generator 403. The fuel target generator 403 may include a fuel discharger. One or more laser beams 402 are incident on the target material (e.g., tin) in the plasma-forming region 404. The accumulation of laser energy within the target material generates plasma 407 in the plasma-forming region 404. Emissions, including EUV radiation, are emitted from the plasma 407 during de-excitation and recombination of ions and electrons in the plasma.

[0082]

[0094] EUV radiation is collected and focused by a radiation collector 405 (e.g., radiation collector CO). In some embodiments, the radiation collector 405 may include a near-normal incident radiation collector (sometimes more commonly referred to as a normal incident radiation collector). The radiation collector 405 may be a multilayer structure arranged to reflect EUV radiation (e.g., EUV radiation having a desired wavelength, such as about 13.5 nm). According to some embodiments, the radiation collector 405 may have an elliptical configuration with two foci. As considered herein, the first focal point may be in the plasma-forming region 404, and the second focal point may be in the intermediate focal point 406.

[0083]

[0095] In some embodiments, the laser system 401 may be located relatively far from the radiation source SO. In such cases, one or more laser beams 402 may pass from the laser system 401 to the radiation source SO using a beam delivery system (not shown) comprising, for example, a suitable guide mirror and / or beam expander and / or other optical systems. The laser system 401 and the radiation source SO may be considered together as a radiation system.

[0084]

[0096] The radiation reflected by the radiation collector 405 forms a radiation beam B. The radiation beam B is focused to a point (e.g., an intermediate focus 406) to form an image of the plasma-forming region 404, which acts as a virtual radiation source for the illumination system IL. The point to which the radiation beam B is focused may be referred to as the intermediate focus (IF) (e.g., intermediate focus 406). The radiation source SO is positioned such that the intermediate focus 406 is located at or near the aperture 408 of the closed structure 409 of the radiation source SO.

[0085]

[0097] The radiant beam B passes from the radiation source SO into the illumination system IL. The illumination system IL is configured to adjust the radiant beam B. The radiant beam B moves out of the illumination system IL and enters a patterning device MA held by a support structure MT. The patterning device MA reflects the radiant beam B and patterns it. After being reflected from the patterning device MA, the patterned radiant beam B enters the projection system PS. The projection system comprises multiple mirrors configured to project the radiant beam B onto a substrate W held by a substrate table WT. The projection system PS can apply a reduction factor to the radiant beam to form an image with features smaller than the corresponding features on the patterning device MA. For example, a reduction factor of 4 can be applied. In Figure 2, the projection system PS is shown as having two mirrors, but the projection system may have any number of mirrors (e.g., six mirrors).

[0086]

[0098] The SO radiation source may also have components not shown in Figure 4. For example, the SO radiation source may be equipped with a spectral filter. This spectral filter may be substantially transparent to EUV radiation but substantially block other radiation wavelengths, such as infrared radiation.

[0087]

[0099] The radiation source SO (or radiation system) may further include a fuel target imaging system for obtaining an image of the fuel target (e.g., a droplet) in the plasma-forming region 404, and more specifically, an image of the shadow of the fuel target. The fuel target imaging system can detect light diffracted from the edges of the fuel target. References to images of the fuel target in the following description should be understood to also refer to images of the shadow of the fuel target or the diffraction patterns produced by the fuel target.

[0088]

[0100] The fuel target imaging system may include a photodetector such as a CCD array or a CMOS sensor, but it will be understood that any imaging device suitable for obtaining an image of the fuel target can be used. It will be understood that the fuel target imaging system may include optical components such as one or more lenses in addition to the photodetector. For example, the fuel target imaging system may include a camera 410, for example, a combination of an optical sensor, i.e., a photodetector, and one or more lenses. The optical components may be selected so that the optical sensor or camera 410 obtains near-field and / or far-field images. The camera 410 may be placed at any suitable location within the radiation source SO, such that the camera has a line of sight to one or more markers (not shown in Figure 4) provided on the plasma-forming region 404 and the radiation collector 405. However, in some embodiments, it may be necessary to place the camera 410 away from the propagation paths of one or more laser beams 402 and the trajectory of the fuel target emitted from the fuel target generator 403 in order to avoid damage to the camera 410. According to some embodiments, the camera 410 is configured to provide an image of the fuel target to a controller 411 via a connection 412. Although connection 412 is shown as a wired connection, it will be understood that connection 412 (and other connections referred to herein) may be implemented as wired connections, wireless connections, or a combination thereof.

[0089]

[0101] As shown in Figure 4, the radiation source SO may include a fuel target generator 403 configured to generate fuel targets 403' (e.g., individual tin droplets) and emit them toward a plasma-forming region 404. The radiation source SO may further include a laser system 401 configured to irradiate one or more laser beams 402 onto one or more of the fuel targets 403' to generate plasma 407 in the plasma-forming region 404. The radiation source SO may further include a radiation collector 405 (e.g., radiation collector CO) configured to collect the radiation emitted by the plasma 407.

[0090] Exemplary Illumination Uniformity Correction System

[0102] Figures 5A and 5B are schematic diagrams of exemplary illumination uniformity correction systems 500 according to some aspects of the present disclosure.

[0091]

[0103] As shown in Figure 5A, the exemplary illumination uniformity correction system 500 may comprise a set of finger assemblies 502 (e.g., 28 finger assemblies with a pitch of approximately x4 mm), a set of finger tips 504 (e.g., each finger assembly includes a corresponding finger tip), a frame 528, a set of flexures 530, and a set of flexures 532. In some embodiments, the exemplary illumination uniformity correction system 500 can modify the intensity of the illumination slits by individually controlling the position of each finger assembly in the set of finger assemblies 502 (e.g., using a motion control system comprising one or more magnet assemblies, etc.) in order to achieve target uniformity.

[0092]

[0104] As shown in Figure 5B, the exemplary illumination uniformity correction system 500 may comprise a radiation source 540 and a radiation detector 560. In some embodiments, the radiation source 540 may be configured to generate radiation 542 and transmit the radiation 542 across a set of finger assemblies 502 toward the radiation detector 560. In some embodiments, the radiation 542 may include a laser curtain. In some embodiments, the exemplary illumination uniformity correction system 500 may be configured to move one or more finger assemblies of the set of finger assemblies 502 into the laser curtain during a wafer exchange operation (e.g., between wafer exposure operations) to check finger tip thermal growth. In some embodiments, the radiation detector 560 may be configured to receive at least a portion of the radiation 542. In some embodiments, the received portion of the radiation 542 may include radiation reflected from the surface of the finger tips of the finger assemblies (e.g., mechanical edges positioned opposite the optical edges) in response to the irradiation of the finger tip surface by the transmitted radiation 542.

[0093]

[0105] In some embodiments, the optical edges of one or more fingertips of a set of fingertips 504 may be exposed to radiation 580 (e.g., DUV or EUV radiation) during the wafer exposure operation of the lithography apparatus, which may cause one or more fingertips to grow as a result of the exposure (or during multiple exposures). In some embodiments, the exemplary illumination uniformity correction system 500 may further include a processor (not shown) configured to determine changes in the shape of one or more finger assemblies of a set of finger assemblies 502 based on the received radiation 542.

[0094]

[0106] Figure 6 is a schematic diagram of an exemplary illumination uniformity correction system 600 according to some aspects of the present disclosure.

[0095]

[0107] As shown in Figure 6, a set of finger assemblies may include a finger assembly 620. The finger assembly 620 may comprise a finger body 622, a finger tip 624, an actuator 626 (for adjusting the position of the finger assembly 620, for example), a position sensor 628 (including, for example, an encoder scale), a flexure 630, and a flexure 632. The finger tip 624 may comprise an optical edge 624a and a mechanical edge 624b. In some embodiments, the optical edge 624a of the finger tip 624 may be exposed to radiation 680 (e.g., DUV or EUV radiation) during the wafer exposure operation of a lithography apparatus, which may cause the finger tip 624 to grow as a result of the exposure (or during multiple exposures).

[0096]

[0108] In some embodiments, the radiation source may be configured to transmit radiation 642 toward the finger assembly 620 (e.g., toward the mechanical edge 624b of the finger tip 624). In some embodiments, the radiation source may be configured to transmit radiation 642 during a wafer change operation of the lithography apparatus (e.g., after a wafer exposure operation), during which the mechanical edge 624b of the finger tip 624 moves across the radiation 642.

[0097]

[0109] In some embodiments, the radiation detector may be configured to receive at least a portion of the radiation 642 in response to the irradiation of a portion of the finger assembly 620 by the radiation 642. In some embodiments, the portion of the finger assembly 620 may include the mechanical edge 624b of the finger tip 624 of the finger assembly 620, which is spaced apart from the optical edge 624a of the finger tip 624 of the finger assembly 620.

[0098]

[0110] In some embodiments, the exemplary illumination uniformity correction system 600 may further include a processor (not shown) configured to determine changes in the shape of one or more finger assemblies of a set of finger assemblies based on received radiation 642. For example, the processor may be configured to determine changes in the position of the optical edge 624a of the finger tip 624 of the finger tip 624 of the finger assembly 620 based on the growth of the finger tip 624 in response to exposure of the finger tip 624 to radiation 680.

[0099]

[0111] In some embodiments, the processor may be further configured to measure changes in the position of reference marks disposed on the finger assembly 620 based on the received radiation. In some embodiments, the processor may be further configured to determine changes in the shape of the finger assembly 620 based on the measured changes in the position of the reference marks.

[0100]

[0112] In some embodiments, the processor may be further configured to generate a control signal configured to correct the position of one or more finger assemblies in a set of finger assemblies based on a change in the shape of one or more finger assemblies in a determined set of finger assemblies. For example, the processor may be configured to generate a control signal configured to correct the position of finger assembly 620 based on a change in the shape of finger assembly 620.

[0101]

[0113] The processor may also be configured to send control signals to motion control systems (including, for example, one or more magnet assemblies) coupled to one or more finger assemblies of the set of finger assemblies. For example, the processor may be configured to send control signals to motion control systems including actuators 626 coupled to finger body 622.

[0102]

[0114] Figure 7 is a schematic diagram of an exemplary illumination uniformity correction system 700 according to some aspects of the present disclosure.

[0103]

[0115] As shown in Figure 7, the exemplary illumination uniformity correction system 700 may comprise a finger assembly having a finger tip 724, a radiation source 740, and radiation detectors 760 for each finger assembly (e.g., 28 radiation detectors for 28 finger assemblies). In some embodiments, the radiation source 740 may be configured to generate radiation and transmit the generated radiation toward a set of reference marks 722 (e.g., one or more reference marks) disposed on the surface 725 of the finger assembly (e.g., the optical surface of the finger assembly). In some embodiments, the radiation source 740 may be configured to transmit radiation during wafer exchange operations of a lithography apparatus (e.g., after a wafer exposure operation). In some embodiments, the radiation detectors 760 may be configured to receive at least a portion of the radiation reflected from the surface 725.

[0104]

[0116] In some embodiments, the exemplary illumination uniformity correction system 700 may further include a processor (not shown) configured to determine changes in the shape of the finger assembly based on the received radiation. For example, the processor may be configured to determine changes in the position of the optical edges of the finger tips 724 of the finger assembly based on the growth of the finger tips 724 in response to exposure of the finger tips 724 to EUV or DUV radiation.

[0105]

[0117] In some embodiments, the processor may be further configured to measure changes in the position of a set of reference marks 722 disposed on the surface 725 of the finger assembly based on the received radiation. In some embodiments, the processor may be further configured to determine changes in the shape of the finger assembly based on the measured changes in the position of the set of reference marks 722.

[0106]

[0118] In some embodiments, the processor may be further configured to generate a control signal configured to correct the position of the finger assembly based on a determined change in the shape of the finger assembly. In some embodiments, the processor may be further configured to transmit the control signal to a motion control system coupled to the finger assembly (including actuators such as a magnet assembly).

[0107]

[0119] Figure 8 is a schematic diagram of an exemplary illumination uniformity correction system 800 according to some aspects of the present disclosure.

[0108]

[0120] As shown in Figure 8, the exemplary illumination uniformity correction system 800 may comprise a finger assembly having a finger tip 824, a radiation source 840, and radiation detectors 860 for each finger assembly (e.g., 28 radiation detectors for 28 finger assemblies). In some embodiments, the radiation source 840 may be configured to generate radiation and transmit the generated radiation toward a set of reference marks 822 (e.g., one or more reference marks) disposed on the surface 823 of the finger assembly (e.g., the mechanical (non-optical) surface of the finger assembly). In some embodiments, the radiation source 840 may be configured to transmit radiation during wafer exchange operations of a lithography apparatus (e.g., after a wafer exposure operation). In some embodiments, the radiation detectors 860 may be configured to receive at least a portion of the radiation reflected from the surface 823.

[0109]

[0121] In some embodiments, the exemplary illumination uniformity correction system 800 may further include a processor (not shown) configured to determine changes in the shape of the finger assembly based on the received radiation. For example, the processor may be configured to determine changes in the position of the optical edges of the finger tips 824 of the finger assembly based on the growth of the finger tips 824 in response to exposure of the finger tips 824 to EUV or DUV radiation.

[0110]

[0122] In some embodiments, the processor may be further configured to measure changes in the position of a set of reference marks 822 disposed on the surface 823 of the finger assembly based on the received radiation. In some embodiments, the processor may be further configured to determine changes in the shape of the finger assembly based on the measured changes in the position of the set of reference marks 822.

[0111]

[0123] In some embodiments, the processor may be further configured to generate a control signal configured to correct the position of the finger assembly based on the determined change in the shape of the finger assembly. In some embodiments, the processor may be further configured to transmit the control signal to a motion control system (including, for example, an actuator) coupled to the finger assembly.

[0112]

[0124] Figure 9 is a schematic diagram of an exemplary set of reference marks 900 relating to some aspects of this disclosure.

[0113]

[0125] As shown in Figure 9, the exemplary set of reference marks 900 may include reference marks 902 (for example, referred to as 902a at time t0 and 902b at time t1) disposed on the surface of the finger assembly. In some embodiments, reference marks 902 may be referred to as fingertip references. The exemplary set of reference marks 900 may further include index marks 904 disposed on the surface of the finger assembly, for example, on the surface of a position sensor (e.g., an encoder) disposed on or attached to the finger assembly. In one exemplary and non-limiting example, index marks 904 may be referred to as “encoder indexes”.

[0114]

[0126] In some embodiments, time t0 may correspond to a time associated with a calibration process performed during the manufacture of the exemplary illumination uniformity correction system, and reference mark 902a may correspond to a reference position on the fingertip measured at time t0, where the value D0 corresponds to the distance from reference mark 902a to index mark 904.

[0115]

[0127] In some embodiments, time t1 may correspond to a time associated with a measurement performed during an operation (e.g., wafer exchange operation, wafer exposure operation), and reference mark 902b may correspond to a reference position on the fingertip measured at time t1, where value D1 corresponds to the distance from reference mark 902b to index mark 904. In some embodiments, value D1 may be greater than value D0 due to fingertip growth during operation of the lithography apparatus. In some embodiments, the change in position of reference mark 902 from time t0 to time t1 may be determined based on the difference between value D0 and value D1. For example, the change in position from reference mark 902a at time t0 to reference mark 902b at time t1 may be proportional to the difference between value D0 and value D1.

[0116]

[0128] Figure 10 is a schematic diagram of an exemplary illumination uniformity correction system 1000 according to some aspects of the present disclosure.

[0117]

[0129] As shown in Figure 10, the exemplary illumination uniformity correction system 1000 may comprise a finger assembly having a fingertip 1024. In some embodiments, the fingertip 1024 may comprise an optical edge 1024a and a mechanical edge 1024b. In some embodiments, the optical edge 1024a of the fingertip 1024 may be exposed to incident radiation 1080 (e.g., DUV radiation, or EUV radiation such as chemical beam EUV light) during the wafer exposure operation of the lithography apparatus, which may cause the fingertip 1024 to grow as a result of the exposure (or during multiple exposures).

[0118]

[0130] In some embodiments, the fingertip 1024 may further include a multilayer mirror material disposed on the surface 1025 of the fingertip 1024. In some embodiments, the multilayer mirror material may include alternating layers of molybdenum and silicon. In some embodiments, the maximum steady-state temperature of the fingertip can be reduced so that the multilayer mirror material remains substantially stable. In some embodiments, the multilayer mirror material can reflect a large portion of the incident radiation to reduce thermal effects while enhancing drift compensation capability and reducing the risk of irretrievable adhesion loss of the fingertip as the radiation source power increases. In some embodiments, the fingertip 1024 may be an angled fingertip, and the multilayer mirror material disposed on the surface 1025 can reflect more than 60 percent of the incident radiation 1080 toward the radiation detector 1090 (e.g., as reflected radiation 1082). As a result, the thermal load on the fingertip 1024 can be reduced, improving the reliability, service life, and performance of the exemplary illumination uniformity correction system 1000.

[0119]

[0131] In some embodiments, the exemplary illumination uniformity correction system 1000 may further include radiation detectors 1090 (e.g., one-dimensional or two-dimensional sensor arrays, "beam-finger tip motion sensors"). In some embodiments, the exemplary illumination uniformity correction system 1000 may include one radiation detector per finger assembly. In some embodiments, a multilayer mirror material may be configured to reflect incident radiation 1080 toward the radiation detector 1090 during the exposure operation of the lithography apparatus. In some embodiments, the radiation detector 1090 may be configured to sense the reflected portion (e.g., reflected radiation 1082) of the incident radiation 1080 used during the wafer exposure operation of the lithography apparatus.

[0120]

[0132] In some embodiments, a set of reference marks may be applied to a region of the multilayer mirror material. In some embodiments, the set of reference marks may include two or more reference marks. In some embodiments, a mark (e.g., configured as a nanoline having a specific shape (e.g., a series of lines) formed by the absorber material, as is done for an EUV reticle) or a set of marks may be applied to a specific region of the multilayer mirror material to improve the detectability, accuracy, or both of the position of the fingertip 1024. In some embodiments, data from other radiation detectors described herein may be combined with data from radiation detector 1090 to eliminate the individual effects of illumination beam movement.

[0121]

[0133] In some embodiments, the exemplary illumination uniformity correction system 1000 may further include a processor (not shown) configured to determine changes in the shape of the fingertip 1024 based on the received radiation. For example, the processor may be configured to determine changes in the position of the optical edge 1024a of the fingertip 1024 based on the growth of the fingertip 1024 in response to exposure of the fingertip 1024 to radiation 1080. In some embodiments, the processor may further be configured to measure changes in the position of a reference mark disposed on the surface 1025 of the fingertip 1024 based on the received radiation. In some embodiments, the processor may further be configured to determine changes in the shape of the fingertip 1024 based on the measured changes in the position of the reference mark. In some embodiments, the processor may further be configured to generate a control signal configured to correct the position of the fingertip 1024 based on the determined changes in the shape of the fingertip 1024. In some embodiments, the processor may further be configured to transmit a control signal to a motion control system (including, for example, an actuator) coupled to the finger assembly. In some embodiments, the processor may be configured to compare reflected radiation 1082 with a previously acquired stored dataset in order to reduce dose and uniformity errors by determining finger positions. As a result, the performance of the exemplary illumination uniformity correction system 1000 may be improved based on the improved accuracy and availability of this beam movement data.

[0122] Exemplary process for adjusting the uniformity of lighting slits

[0134] Figure 11 shows an exemplary method 1100 for adjusting illumination slit uniformity in a lithography apparatus relating to some aspect or part thereof of this disclosure. The operations described with reference to exemplary method 1100 may be performed by or in accordance with any of the systems, apparatus, components, techniques, or combinations thereof described herein, including those described with reference to Figures 1 to 10 above and Figure 12 below.

[0123]

[0135] In operation 1102, the method may include moving one or more finger assemblies to correct slit uniformity. In some embodiments, the movement of one or more finger assemblies may be achieved by appropriate mechanical or other means and may include moving one or more finger assemblies in any embodiment or combination of embodiments described with reference to Figures 1 to 10 above and Figure 12 below.

[0124]

[0136] In operation 1104, the method may include steps performed in parallel with the wafer exchange operation (in some embodiments, the wafer exposure operation), such as measuring and estimating fingertip growth in operation 1106, and correcting the finger assembly position if necessary in operation 1108.

[0125]

[0137] In operation 1106, the method may include measuring and estimating fingertip growth. For example, in operation 1106, the method may include a radiation source irradiating a portion of the finger assembly with radiation. In some embodiments, the radiation may include a laser curtain, and receiving at least a portion of the radiation may include a radiation detector receiving at least a portion of the transmitted radiation in response to the irradiation of a portion of the finger assembly with the laser curtain. In some embodiments, the portion of the finger assembly may include the mechanical edge of the fingertip of the finger assembly, which is spaced apart from the optical edge of the fingertip of the finger assembly. In some embodiments, the irradiation of a portion of the finger assembly may be achieved by appropriate mechanical or other means, and may include irradiating a portion of the finger assembly in any embodiment or combination of embodiments described with reference to Figures 1 to 10 above and Figure 12 below.

[0126]

[0138] Furthermore, in operation 1106, the method may include the radiation detector receiving at least a portion of the radiation in response to the illumination of a portion of the finger assembly. In some embodiments, illumination of a portion of the finger assembly may include the radiation source illuminating a portion of the finger assembly with radiation during a wafer exchange operation of a lithography apparatus. In other embodiments, illumination of a portion of the finger assembly may include the radiation source illuminating a portion of the finger assembly with radiation during a wafer exposure operation of a lithography apparatus. In some embodiments, receiving at least a portion of the radiation may include the radiation detector receiving radiation reflected from the surface of the finger tip of the finger assembly in response to the illumination of the surface of the finger tip with radiation. In some embodiments, the reception of radiation may be achieved by appropriate mechanical or other means and may include receiving radiation in accordance with any embodiment or combination of embodiments described with reference to Figures 1 to 10 above and Figure 12 below.

[0127]

[0139] Furthermore, in operation 1106, the method may include the processor determining a change in the shape of the finger assembly based on the received radiation. In some embodiments, determining a change in the shape of the finger assembly may include the processor determining a change in the position of the optical edge of the finger tip of the finger assembly based on the growth of the finger tip in response to exposure of the finger tip to DUV or EUV radiation. In some embodiments, determining a change in the shape of the finger assembly may include the processor measuring a change in the position of a reference mark disposed on the finger assembly based on the received radiation. In some embodiments, determining a change in the shape of the finger assembly may further include the processor determining a change in the shape of the finger assembly based on the measured change in the position of the reference mark. In some embodiments, the reference mark is affixed to a region of multilayer mirror material disposed on the finger tip of the finger assembly. For example, in such embodiments, the method may include the radiation detector sensing the reflective portion of the chemical beam EUV light used during the wafer exposure operation of the lithography apparatus. In some embodiments, the determination of the change may be achieved by appropriate mechanical or other means, and may include determining the change in any embodiment or combination of embodiments described with reference to Figures 1 to 10 above and Figure 12 below.

[0128]

[0140] In operation 1108, the method may include correcting the finger assembly position if necessary. For example, in operation 1106, the method may include the processor generating a control signal configured to correct the position of the finger assembly based on a determined change in the shape of the finger assembly. Furthermore, in operation 1106, the method may include the processor transmitting a control signal to a motion control system coupled to the finger assembly. In some embodiments, correction of the finger assembly position may be achieved by appropriate mechanical or other means and may include correcting the finger assembly position in any embodiment or combination of embodiments described with reference to Figures 1 to 10 above and Figure 12 below.

[0129]

[0141] In operation 1110, the method may include determining whether the wafer lot is complete. If not, the method may proceed to operation 1102. If it is complete, the method may proceed to operation 1112. In operation 1112, the method may include determining whether a uniformity refresh (UR) should be performed. If not, the method may proceed to operation 1102. If it should be performed, the method may proceed to operation 1114. In operation 1114, the method may include performing UR correction.

[0130] Exemplary computing systems

[0142] Aspects of this disclosure may be implemented in hardware, firmware, software, or any combination thereof. Aspects of this disclosure may also be implemented as instructions stored in a machine-readable medium that can be read and executed by one or more processors. The machine-readable medium may include any mechanism for storing or transmitting information in a format readable by a machine (e.g., a computing device). For example, the machine-readable medium may include read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, and propagating signals of electrical, optical, acoustic, or other forms (e.g., carrier waves, infrared signals, digital signals, etc.). Furthermore, firmware, software, routines, instructions, and combinations thereof may be described herein as performing specific operations. However, it should be understood that such descriptions are merely for convenience, and that such actions actually result from computing devices, processors, controllers, or other devices executing firmware, software, routines, instructions, or combinations thereof, and in doing so, causing actuators or other devices (e.g., servo motors, robotic devices) to interact with the physical world.

[0131]

[0143] Various embodiments may be implemented using one or more computing systems, such as the exemplary computing system 1200 shown in Figure 12. The exemplary computing system 1200 may be a dedicated computer capable of performing the functions described herein, such as the exemplary lighting uniformity correction system 500 shown in Figures 5A and 5B, the exemplary lighting uniformity correction system 600 shown in Figure 6, the exemplary lighting uniformity correction system 700 shown in Figure 7, the exemplary lighting uniformity correction system 800 shown in Figure 8, the exemplary lighting uniformity correction system 1000 shown in Figure 10, any system, subsystem or component described with reference to Figure 11, any other suitable system, subsystem or component, or any combination thereof. The exemplary computing system 1200 may include one or more processors (also called a central processing unit, i.e., CPU), such as processor 1204. Processor 1204 is connected to a communication infrastructure 1206 (e.g., a bus). The exemplary computing system 1200 may also include one or more user input / output devices 1203, such as a monitor, keyboard, and pointing device, which communicate with a communication infrastructure 1206 via one or more user input / output interfaces 1202. The exemplary computing system 1200 may also include main memory 1208 (e.g., one or more primary storage devices), such as random access memory (RAM). The main memory 1208 may include one or more levels of cache. The main memory 1208 internally stores control logic (e.g., computer software) and / or data.

[0132]

[0144] The exemplary computing system 1200 may also include secondary memory 1210 (e.g., one or more secondary storage devices). Secondary memory 1210 may include, for example, a hard disk drive 1212 and / or a removable storage drive 1214. The removable storage drive 1214 may be a floppy disk drive, a magnetic tape drive, a compact disk drive, an optical storage device, a tape backup device, and / or any other storage device / drive.

[0133]

[0145] The removable storage drive 1214 can interact with the removable storage unit 1218. The removable storage unit 1218 includes a computer-readable or computer-enabled storage device that stores computer software (control logic) and / or data. The removable storage unit 1218 may be a floppy disk, magnetic tape, compact disk, DVD, optical storage disk, and / or any other computer data storage device. The removable storage drive 1214 reads from and / or writes to the removable storage unit 1218.

[0134]

[0146] In some embodiments, the secondary memory 1210 may include other means, devices, or other techniques for enabling computer programs and / or other instructions and / or data to be accessed by the exemplary computing system 1200. Such means, devices, or techniques may include, for example, a removable storage unit 1222 and an interface 1220. Examples of the removable storage unit 1222 and interface 1220 may include a program cartridge and cartridge interface (such as those found in video game devices), a removable memory chip (such as an EPROM or PROM) and associated sockets, a memory stick and USB port, a memory card and associated memory card slot, and / or any other removable storage unit and associated interface.

[0135]

[0147] The exemplary computing system 1200 may further include a communication interface 1224 (e.g., one or more network interfaces). The communication interface 1224 enables the exemplary computing system 1200 to communicate and interact with any combination of remote devices, remote networks, remote entities, etc. (individually and collectively referred to as remote devices 1228). For example, the communication interface 1224 may enable communication between the exemplary computing system 1200 and the remote devices 1228, which may be wired and / or wireless via a communication channel 1226, and may include any combination of LAN, WAN, internet, etc. Control logic, data, or both may be transmitted to and from the exemplary computing system 1200 via the communication channel 1226.

[0136]

[0148] The operations of the aforementioned embodiments of this disclosure may be implemented in a variety of configurations and architectures. Therefore, some or all of the operations of the aforementioned embodiments may be performed in hardware, software, or both. In some embodiments, a tangible non-temporary device or product includes a tangible non-temporary computer-usable or computer-readable medium storing control logic (software), also referred to herein as a computer program product or program storage device. This includes, but is not limited to, the exemplary computing system 1200, the main memory 1208, the secondary memory 1210, and the removable storage units 1218 and 1222, and tangible products embodying any combination thereof. When such control logic is executed by one or more data processing devices (such as the exemplary computing system 1200), it causes such data processing devices to perform the operations described herein.

[0137]

[0149] Based on the teachings contained herein, methods for implementing and using embodiments of the disclosure using data processing devices, computer systems, and / or computer architectures other than those shown in Figure 12 will become apparent to those skilled in the art. Specifically, embodiments of the disclosure may operate in software, hardware, and / or operating system implementations other than those described herein.

[0138]

[0150] Embodiments of this disclosure may be further described by the following clauses. 1. A radiation source configured to generate radiation and transmit the generated radiation toward a finger assembly, and a radiation detector configured to receive at least a portion of the transmitted radiation, A processor configured to determine a change in the shape of a finger assembly based on received radiation, generate a control signal configured to correct the position of the finger assembly based on the determined change in the shape of the finger assembly, and transmit the control signal to a motion control system coupled to the finger assembly, A system equipped with these features. 2. The system of Clause 1, wherein the determined change in the shape of the finger assembly includes a change in the position of the optical edge of the fingertip based on the growth of the fingertip in response to exposure of the fingertip of the finger assembly to deep ultraviolet (DUV) radiation or extreme ultraviolet (EUV) radiation. 3. The system of Clause 1, wherein the radiation source is configured to transmit radiation during wafer change operations of the lithography apparatus. 4. The generated radiation includes the laser curtain, The system according to Clause 1, wherein the radiation detector is configured to receive at least a portion of the radiation transmitted in response to the illumination of a portion of the finger assembly by a laser curtain. 5. The system of Clause 4, wherein a portion of the finger assembly includes the mechanical edge of the fingertip of the finger assembly, which is positioned spaced apart from the optical edge of the fingertip of the finger assembly. 6. The system of Clause 1, wherein the received radiation includes radiation reflected from the surface of the fingertip in response to the irradiation of the surface of the fingertip of the finger assembly by the transmitted radiation. 7. The processor, Based on the received radiation, the change in the position of a reference mark placed on the finger assembly is measured. The change in the shape of the finger assembly is determined based on the change in the position of the measured reference mark. The system of Clause 1 is configured as follows. 8. The system of Clause 7, wherein the reference mark is affixed to the area of ​​the multilayer mirror material placed on the fingertip of the finger assembly. 9. A method for adjusting the uniformity of the illumination slit in a lithography apparatus, The radiation source irradiates a portion of the finger assembly with radiation. The radiation detector receives at least a portion of the radiation in response to the illumination of a portion of the finger assembly. The processor determines the shape change of the finger assembly based on the received radiation. The processor generates a control signal configured to correct the position of the finger assembly based on the determined change in the shape of the finger assembly, and The processor transmits control signals to the motion control system coupled to the finger assembly. Methods that include... 10. The method of Clause 9, wherein determining a change in the shape of a finger assembly involves the processor determining a change in the position of the optical edge of the fingertip based on the growth of the fingertip in response to exposure of the fingertip of the finger assembly to deep ultraviolet (DUV) radiation or extreme ultraviolet (EUV) radiation. 11. The method of Clause 9, wherein irradiating a portion of the finger assembly includes irradiating a portion of the finger assembly with radiation during a wafer change operation of a lithography apparatus. 12. The radiation includes a laser curtain, The method of Clause 9, wherein receiving at least a portion of the radiation includes receiving at least a portion of the radiation transmitted by a radiation detector in response to illuminating a portion of a finger assembly with a laser curtain. 13. The method of Clause 12, wherein a portion of the finger assembly includes the mechanical edge of the finger tip of the finger assembly, which is positioned spaced apart from the optical edge of the finger tip of the finger assembly. 14. The method of Clause 9, wherein receiving at least a portion of the radiation includes receiving radiation reflected from the surface of the fingertip in response to the radiation detector irradiating the surface of the fingertip of the finger assembly with radiation. 15. Determining the change in the shape of the finger assembly is The processor measures the change in the position of a reference mark placed on the finger assembly based on the received radiation, and The processor determines the change in the shape of the finger assembly based on the change in the position of the measured reference mark. The method of Article 9, including the method of Article 9. 16. The method of Clause 15, wherein a reference mark is applied to an area of ​​multilayer mirror material placed on the fingertip of the finger assembly. 17. Finger body and, Fingertip and A multilayer mirror material placed on the surface of the fingertip, A set of reference marks applied to the region of the multilayer mirror material, A device comprising a finger assembly including a 18. The apparatus of Clause 17, wherein the set of standard marks includes two or more standard marks. 19. The apparatus of Clause 17, wherein the multilayer mirror material is configured to reflect deep ultraviolet (DUV) radiation or extreme ultraviolet (EUV) radiation toward a radiation detector during the exposure operation of the lithography apparatus. 20. Apparatus of Clause 17, wherein the multilayer mirror material contains molybdenum.

[0139]

[0151] While this specification may contain specific references to the use of lithography equipment in the manufacture of ICs, it should be understood that the lithography equipment described herein may have other applications, such as the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memory, flat panel displays, LCDs, thin-film magnetic heads, etc. In relation to such alternative applications, it should be understood by those skilled in the art that the terms “wafer” or “die” used herein may be considered synonymous with the more general terms “substrate” or “target portion,” respectively. The substrates referred to herein may be processed before or after exposure in, for example, a track unit (generally a tool for coating a resist layer onto a substrate and developing the exposed resist), a metrology unit, and / or an inspection unit. Where applicable, the disclosures herein may apply to the above and other substrate processing tools. Furthermore, the substrate may be processed more than once to manufacture, for example, a multilayer IC, and as a result, the term “substrate” as used herein may also refer to a substrate that already contains multiple processed layers.

[0140]

[0152] It should be understood that the terms and technical terms used herein are for illustrative purposes only, and not for limitation, so that they may be interpreted by those skilled in the art in light of the teachings herein.

[0141]

[0153] As used herein, the term “substrate” refers to a material on which a layer of material is added. In some embodiments, the substrate itself may be patterned, and the material added on the substrate may also be patterned or remain unpatterned.

[0142]

[0154] The examples disclosed herein are illustrative of embodiments of this disclosure and are not limiting. Other suitable variations and adaptations of various conditions and parameters commonly encountered in the art (which will be apparent to those skilled in the art) are within the spirit and scope of this disclosure.

[0143]

[0155] While specific embodiments of this disclosure have been described above, it will be understood that these embodiments may be implemented in ways other than those described. These descriptions are not intended to limit the embodiments of this disclosure.

[0144]

[0156] It should be understood that the detailed description section, rather than the background, overview, and abstract section, is intended to be used to interpret the claims. The overview and abstract section may describe one or more (but not all) exemplary embodiments as contemplated by the inventors, and is therefore not intended in any way to limit these embodiments and the appended claims.

[0145]

[0157] Some aspects of this disclosure are described above using functional configuration blocks that illustrate the implementation of specific functions and their relationships. The boundaries of these functional configuration blocks are arbitrarily defined herein for the sake of clarity. Different boundaries may be defined, insofar as the specific functions and their relationships are adequately performed.

[0146]

[0158] The above descriptions of specific embodiments of this disclosure will fully reveal the general nature of the embodiments so that others may readily modify and / or adapt such specific embodiments for various uses without excessive experimentation and without departing from the general concepts of this disclosure, by applying knowledge within the scope of their skills in the art. Accordingly, such adaptations and modifications are intended to be within the meaning and scope of equivalents of the disclosed embodiments, based on the teachings and guidance presented herein.

[0147]

[0159] The breadth and scope of this disclosure shall not be limited by any of the exemplary embodiments or models described above, but shall be defined solely by the following claims and their equivalents.

Claims

1. A system for adjusting the uniformity of illumination slits in a lithography apparatus, A radiation source configured to generate radiation and transmit the generated radiation toward a finger assembly, A radiation detector configured to receive at least a portion of the transmitted radiation, A processor configured to determine a change in the shape of the finger assembly based on the received radiation, generate a control signal configured to correct the position of the finger assembly based on the determined change in the shape of the finger assembly, and transmit the control signal to a motion control system coupled to the finger assembly, A set of reference marks comprising a reference mark disposed on the surface of the finger assembly and an index mark disposed on the surface of the finger assembly or the surface of a position sensor attached to the finger assembly, A system equipped with these features.

2. The system of claim 1, wherein the change in the shape of the determined finger assembly includes a change in the position of the optical edge of the fingertip based on the growth of the fingertip in response to exposure of the fingertip of the finger assembly to deep ultraviolet (DUV) radiation or extreme ultraviolet (EUV) radiation.

3. The system according to claim 1, wherein the radiation source is configured to transmit the radiation during wafer exchange operations of the lithography apparatus.

4. The generated radiation includes a laser curtain, The system according to claim 1, wherein the radiation detector is configured to receive at least a portion of the transmitted radiation in response to irradiation of a portion of the finger assembly by the laser curtain.

5. The system of claim 4, wherein the portion of the finger assembly includes the mechanical edge of the finger tip of the finger assembly, which is disposed spaced apart from the optical edge of the finger tip of the finger assembly.

6. The system according to claim 1, wherein the received radiation includes radiation reflected from the surface of the fingertip in response to the irradiation of the surface of the fingertip of the finger assembly by the transmitted radiation.

7. The aforementioned processor, Based on the received radiation, the change in the position of the reference mark relative to the index mark is measured. Based on the change in the position of the measured reference mark, the change in the shape of the finger assembly is determined. The system according to claim 1, configured as follows.

8. The system according to claim 1, wherein the reference mark is applied to a region of multilayer mirror material disposed on the fingertip of the finger assembly.

9. A method for adjusting the uniformity of the illumination slit in a lithography apparatus, The radiation source irradiates a portion of the finger assembly with radiation. The radiation detector receives at least a portion of the radiation in response to the irradiation of the portion of the finger assembly. The processor determines the change in the shape of the finger assembly based on the received radiation. The processor generates a control signal configured to correct the position of the finger assembly based on the determined change in the shape of the finger assembly, and The processor includes transmitting the control signal to the motion control system coupled to the finger assembly, Determining the change in the shape of the finger assembly is A method comprising the processor determining the change in the shape of the finger assembly by measuring the change in the position of a reference mark disposed on the surface of the finger assembly relative to an index mark disposed on the surface of the finger assembly or on the surface of a position sensor attached to the finger assembly.

10. The method of claim 9, wherein determining the change in the shape of the finger assembly includes the processor determining a change in the position of the optical edge of the fingertip based on the growth of the fingertip in response to exposure of the fingertip of the finger assembly to deep ultraviolet (DUV) radiation or extreme ultraviolet (EUV) radiation.

11. The method of claim 9, wherein irradiating the portion of the finger assembly includes the radiation source transmitting the radiation during the wafer exchange operation of the lithography apparatus to irradiate the portion of the finger assembly with the radiation.

12. The radiation includes a laser curtain, The method of claim 11, wherein receiving the at least portion of the radiation includes receiving the at least portion of the transmitted radiation in response to the radiation detector irradiating the portion of the finger assembly with the laser curtain.

13. The method of claim 12, wherein the portion of the finger assembly includes the mechanical edge of the finger tip of the finger assembly, which is disposed spaced apart from the optical edge of the finger tip of the finger assembly.

14. The method of claim 9, wherein receiving at least a portion of the radiation includes receiving radiation reflected from the surface of the fingertip in response to the radiation detector irradiating the surface of the fingertip of the finger assembly with the radiation.

15. The method of claim 9, wherein the reference mark is applied to a region of multilayer mirror material disposed on the fingertip of the finger assembly.

16. A device for adjusting the uniformity of illumination slits in a lithography apparatus, Finger body and Fingertip and A multilayer mirror material disposed on the surface of the fingertip, A set of reference marks applied to the region of the multilayer mirror material, A finger assembly including The apparatus comprises a set of reference marks, a reference mark disposed on the surface of the finger assembly, and an index mark disposed on the surface of the finger assembly or on the surface of a position sensor attached to the finger assembly.

17. The apparatus of claim 16, wherein the set of reference marks includes two or more reference marks.

18. The apparatus according to claim 16, wherein the multilayer mirror material is configured to reflect deep ultraviolet (DUV) radiation or extreme ultraviolet (EUV) radiation toward a radiation detector during the exposure operation of the lithography apparatus.

19. The apparatus according to claim 16, wherein the multilayer mirror material contains molybdenum.

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