WO2020187713A1

WO2020187713A1 - Micromanipulator devices and metrology system

Info

Publication number: WO2020187713A1
Application number: PCT/EP2020/056745
Authority: WO
Inventors: Damoon SOHRABIBABAHEIDARY; Tammo Uitterdijk; Christopher John MASON; Benjamin David DAWSON; Mehmet Ali AKBAS; Keane Michael LEVY
Original assignee: Asml Holding N.V.
Priority date: 2019-03-18
Filing date: 2020-03-13
Publication date: 2020-09-24
Also published as: CN113614642A; NL2025117A

Abstract

A device for removing a portion of an object includes a stage, a metrology apparatus, a material removal device, and an actuator. The metrology apparatus includes a radiation source, an optical system, and a detector. The material removal device includes an elongate element and a sharp element at an end of the elongate element. The stage supports the object. The radiation source generates radiation. The optical system directs the radiation toward the portion of the object. The detector receives radiation scattered by the portion of the object and outputs data based on the received radiation. The data comprises a position of the portion of the object. The actuator moves the material removal device such that the sharp element is disposed on the position of the portion of the object. The device exerts a force on the portion of the object such that the portion of the object can be dislodged.

Description

MICROMANIPULATOR DEVICES AND METROLOGY SYSTEM

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority of (1) U.S. Provisional Patent Application Number

62/819,873, which was filed on March 18, 2019, and (2) U.S. Provisional Patent Application Number 62/954,785, which was filed on December 30, 2019, both of which are incorporated herein in its entirety by reference.

FIELD

[0002] The present disclosure relates to micromanipulator devices and metrology systems, for example, micromanipulator devices for removing excess materials at a microscopic scale.

BACKGROUND

[0003] A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that instance, a patterning device, which is alternatively referred to as a mask or a reticle, can be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can be transferred onto a target portion (e.g., comprising part of, one, or several dies) on a substrate (e.g., a silicon wafer). Transfer of the pattern is typically via imaging onto a layer of radiation- sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned. Known lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion at one time, and so-called scanners, in which each target portion is irradiated by scanning the pattern through a radiation beam in a given direction (the“scanning”-direction) while synchronously scanning the target portions parallel or anti-parallel to this scanning direction. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.

[0004] A substrate table on which a substrate is supported during lithographic and metrology processes requires a flatness tolerance that can be difficult to meet. Wafers (e.g., semiconductor substrate), being relatively thin (e.g., < 1 mm thick) compared to a width of its surface area (e.g., > 100 mm), are particularly sensitive to unevenness of the substrate table. A protrusion on the substrate table in the order of a few tens of microns can warp a substrate enough to adversely impact subsequent lithographic and metrology processes performed on the substrate. It is desirable to develop a device and method that can pinpoint and remove microscopic protrusion on a flat surface that may be difficult to remove using other polishing or area- flattening techniques.

SUMMARY

[0005] In some embodiments, a micromanipulator device comprises a stage, a metrology apparatus, a material removal device, and an actuator. The metrology apparatus comprises a radiation source, an optical system, and a detector. The material removal device comprises an elongate element and a sharp element at an end of the elongate element. The stage supports the object. The radiation source generates radiation. The optical system directs the radiation toward the portion of the object. The detector receives radiation scattered by the portion of the object and outputs data based on the received radiation. The data comprises a position of the portion of the object. The actuator moves the material removal device such that the sharp element is disposed on the position of the portion of the object. The material removal device exerts a force on the portion of the object such that the portion of the object can be dislodged.

[0006] In some embodiments, a metrology system comprises a stage, a radiation source, an optical system, a detector, a material removal device, and an actuator. The material removal device comprises an elongate element and a sharp element at an end of the elongate element. The stage supports the object. The radiation source generates radiation. The optical system directs the radiation toward the portion of the object. The detector receives radiation scattered by the portion of the object and output data based on the received radiation, wherein the data comprises a position of the portion of the object. The actuator moves the material removal device such that the sharp element is disposed on the position of the portion of the object. The material removal device exerts a force on the portion of the object such that the portion of the object can be dislodged and the metrology system measures a property of the dislodged portion of the object.

[0007] In some embodiments, a micromanipulator device comprises a stage, a metrology apparatus, a material dispensing device, and an actuator. The metrology apparatus comprises a radiation source, an optical system, and a detector. The material dispensing device comprises a dispensing end. The stage supports the object. The radiation source generates radiation. The optical system directs the radiation toward a target on the object. The detector receives radiation scattered by the projection and output data based on the received radiation. The data comprises a position of the target on the object. The material dispensing device dispenses a bonding agent. The actuator moves the material dispensing device such that the dispensing end is disposed on the position of the target. A dimension of the bonding agent dispensed by the material dispensing device is less than approximately 50 microns and a smallest movement step of the material dispensing device is less than approximately 0.1 micron.

[0008] Further features of the present disclosure, as well as the structure and operation of various embodiments, are described in detail below with reference to the accompanying drawings. It is noted that the present disclosure is not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

[0009] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable a person skilled in the relevant art(s) to make and use the embodiments described herein.

[0010] FIG. 1A shows a schematic of a reflective lithographic apparatus, according to some embodiments.

[0011] FIG. IB shows a schematic of a transmissive lithographic apparatus, according to some embodiments.

[0012] FIG. 2 shows a more detailed schematic of the reflective lithographic apparatus, according to some embodiments.

[0013] FIG. 3 shows a schematic of a lithographic cell, according to some embodiments.

[0014] FIGS. 4 shows a schematic of a substrate stage, according to some embodiments.

[0015] FIG. 5 shows a schematic of a micromanipulator device, according to some embodiments.

[0016] FIG. 6 shows a schematic of a metrology system, according to some embodiments.

[0017] FIGS. 7 and 8 show systems for performing metrology measurements and precision removal of materials, according to some embodiments. [0018] FIG. 9 shows method steps for performing metrology measurements and precision removal of materials, according to some embodiments.

[0019] The features of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. Additionally, generally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears. Unless otherwise indicated, the drawings provided throughout the disclosure should not be interpreted as to-scale drawings.

DETAILED DESCRIPTION

[0020] This specification discloses one or more embodiments that incorporate the features of the present disclosure. The disclosed embodiment(s) are provided as examples. The scope of the present disclosure is not limited to the disclosed embodiment(s). Claimed features are defined by the claims appended hereto.

[0021] The embodiment(s) described, and references in the specification to “one embodiment,”“an embodiment,”“an example embodiment,” etc., indicate that the embodiment(s) described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is understood that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0022] Spatially relative terms, such as “beneath,” “below,”“lower,” “above,”“on,”

“upper” and the like, can be used herein for ease of description to describe one element or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly. [0023] The term“about” as used herein indicates the value of a given quantity that can vary based on a particular technology. Based on the particular technology, the term“about” can indicate a value of a given quantity that varies within, for example, 10-30% of the value (e.g., ±10%, ±20%, or ±30% of the value).

[0024] Embodiments of the disclosure can be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the disclosure may also be implemented as instructions stored on a machine-readable medium, which can be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, a machine- readable medium may include read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory devices; electrical, optical, acoustical or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.), and others. Further, firmware, software, routines, and/or instructions can be described herein as performing certain actions. However, it should be appreciated that such descriptions are merely for convenience and that such actions in fact result from computing devices, processors, controllers, or other devices executing the firmware, software, routines, instructions, etc.

[0025] Before describing such embodiments in more detail, however, it is instructive to present example environments in which embodiments of the present disclosure can have an impact.

[0026] Example Lithographic Systems

[0027] FIGS. 1A and IB show schematic illustrations of a lithographic apparatus 100 and lithographic apparatus 100’, respectively, in which embodiments of the present disclosure can be implemented. Fithographic apparatus 100 and lithographic apparatus 100’ each include the following: an illumination system (illuminator) IF configured to condition a radiation beam B (for example, deep ultra violet or extreme ultra violet radiation); a support structure (for example, a mask table) MT configured to support a patterning device (for example, a mask, a reticle, or a dynamic patterning device) MA and connected to a first positioner PM configured to accurately position the patterning device MA; and, a substrate table (for example, a wafer table) WT configured to hold a substrate (for example, a resist coated wafer) W and connected to a second positioner PW configured to accurately position the substrate W. Fithographic apparatus 100 and 100’ also have a projection system PS configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion (for example, comprising one or more dies) C of the substrate W. In lithographic apparatus 100, the patterning device MA and the projection system PS are reflective. In lithographic apparatus 100’, the patterning device MA and the projection system PS are transmissive.

[0028] The illumination system IL can include various types of optical components, such as refractive, reflective, catadioptric, magnetic, electromagnetic, electrostatic, or other types of optical components, or any combination thereof, for directing, shaping, or controlling the radiation beam B .

[0029] The support structure MT holds the patterning device MA in a manner that depends on the orientation of the patterning device MA with respect to a reference frame, the design of at least one of the lithographic apparatus 100 and 100’, and other conditions, such as whether or not 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 can be a frame or a table, for example, which can be fixed or movable, as required. By using sensors, the support structure MT can ensure that the patterning device MA is at a desired position, for example, with respect to the projection system PS.

[0030] The term“patterning device” MA should be broadly interpreted as referring to any device that can be used to impart a radiation beam B with a pattern in its cross-section, such as to create a pattern in the target portion C of the substrate W. The pattern imparted to the radiation beam B can correspond to a particular functional layer in a device being created in the target portion C to form an integrated circuit.

[0031] The patterning device MA can be transmissive (as in lithographic apparatus 100’ of FIG. IB) or reflective (as in lithographic apparatus 100 of FIG. 1A). Examples of patterning devices MA include reticles, masks, programmable mirror arrays, or programmable LCD panels. Masks are well known in lithography, and include mask types such as binary, alternating phase shift, or attenuated phase shift, as well as various hybrid mask types. An example of a programmable mirror array employs a matrix arrangement of small mirrors, each of which can be individually tilted so as to reflect an incoming radiation beam in different directions. The tilted mirrors impart a pattern in the radiation beam B, which is reflected by a matrix of small mirrors.

[0032] The term“projection system” PS can encompass any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems, or any combination thereof, as appropriate for the exposure radiation being used, or for other factors, such as the use of an immersion liquid on the substrate W or the use of a vacuum. A vacuum environment can be used for EUV or electron beam radiation since other gases can absorb too much radiation or electrons. A vacuum environment can therefore be provided to the whole beam path with the aid of a vacuum wall and vacuum pumps.

[0033] Lithographic apparatus 100 and/or lithographic apparatus 100’ can be of a type having two (dual stage) or more substrate tables WT (and/or two or more mask tables). In such “multiple stage” machines, the additional substrate tables WT can be used in parallel, or preparatory steps can be carried out on one or more tables while one or more other substrate tables WT are being used for exposure. In some situations, the additional table may not be a substrate table WT.

[0034] The lithographic apparatus can also be of a type wherein at least a portion of the substrate can be covered by a liquid having a relatively high refractive index, e.g., water, so as to fill a space between the projection system and the substrate. An immersion liquid can also be applied to other spaces in the lithographic apparatus, for example, between the mask and the projection system. Immersion techniques are well known in the art for increasing the numerical aperture of projection systems. The term“immersion” as used herein does not mean that a structure, such as a substrate, must be submerged in liquid, but rather only means that liquid is located between the projection system and the substrate during exposure.

[0035] Referring to FIGS. 1A and IB, the illuminator IL receives a radiation beam from a radiation source SO. The source SO and the lithographic apparatus 100, 100’ can be separate physical entities, for example, when the source SO is an excimer laser. In such cases, the source SO is not considered to form part of the lithographic apparatus 100 or 100’, and the radiation beam B passes from the source SO to the illuminator IL with the aid of a beam delivery system BD (in FIG. IB) including, for example, suitable directing mirrors and/or a beam expander. In other cases, the source SO can be an integral part of the lithographic apparatus 100, 100’, for example, when the source SO is a mercury lamp. The source SO and the illuminator IL, together with the beam delivery system BD, if required, can be referred to as a radiation system.

[0036] The illuminator IL can include an adjuster AD (in FIG. IB) for adjusting the angular intensity distribution of the radiation beam. Generally, at least the outer and/or inner radial extent (commonly referred to as“s-outer” and“s-inner,” respectively) of the intensity distribution in a pupil plane of the illuminator can be adjusted. In addition, the illuminator IL can comprise various other components (in FIG. IB), such as an integrator IN and a condenser CO. The illuminator IL can be used to condition the radiation beam B to have a desired uniformity and intensity distribution in its cross section.

[0037] Referring to FIG. 1A, the radiation beam B is incident on the patterning device (for example, mask) MA, which is held on the support structure (for example, mask table) MT, and is patterned by the patterning device MA. In lithographic apparatus 100, the radiation beam B is reflected from the patterning device (for example, mask) MA. After being reflected from the patterning device (for example, mask) MA, the radiation beam B passes through the projection system PS, which focuses the radiation beam B onto a target portion C of the substrate W. With the aid of the second positioner PW and position sensor IF2 (for example, an interferometric device, linear encoder, or capacitive sensor), the substrate table WT can be moved accurately (for example, so as to position different target portions C in the path of the radiation beam B). Similarly, the first positioner PM and another position sensor IF1 can be used to accurately position the patterning device (for example, mask) MA with respect to the path of the radiation beam B. Patterning device (for example, mask) MA and substrate W can be aligned using mask alignment marks Ml, M2 and substrate alignment marks PI, P2.

[0038] Referring to FIG. IB, the radiation beam B is incident on the patterning device (for example, mask MA), which is held on the support structure (for example, mask table MT), and is patterned by the patterning device. Having traversed the mask MA, the radiation beam B passes through the projection system PS, which focuses the beam onto a target portion C of the substrate W. The projection system has a pupil conjugate PPU to an illumination system pupil IPU. Portions of radiation emanate from the intensity distribution at the illumination system pupil IPU and traverse a mask pattern without being affected by diffraction at the mask pattern and create an image of the intensity distribution at the illumination system pupil IPU.

[0039] The projection system PS projects an image MP’ of the mask pattern MP, where image MP’ is formed by diffracted beams produced from the mark pattern MP by radiation from the intensity distribution, onto a photoresist layer coated on the substrate W. For example, the mask pattern MP can include an array of lines and spaces. A diffraction of radiation at the array and different from zeroth order diffraction generates diverted diffracted beams with a change of direction in a direction perpendicular to the lines. Undiffracted beams (i.e., so-called zeroth order diffracted beams) traverse the pattern without any change in propagation direction. The zeroth order diffracted beams traverse an upper lens or upper lens group of the projection system PS, upstream of the pupil conjugate PPU of the projection system PS, to reach the pupil conjugate PPU. The portion of the intensity distribution in the plane of the pupil conjugate PPU and associated with the zeroth order diffracted beams is an image of the intensity distribution in the illumination system pupil IPU of the illumination system IL. The aperture device PD, for example, is disposed at or substantially at a plane that includes the pupil conjugate PPU of the projection system PS.

[0040] The projection system PS is arranged to capture, by means of a lens or lens group

L, not only the zeroth order diffracted beams, but also first-order or first- and higher-order diffracted beams (not shown). In some embodiments, dipole illumination for imaging line patterns extending in a direction perpendicular to a line can be used to utilize the resolution enhancement effect of dipole illumination. For example, first-order diffracted beams interfere with corresponding zeroth-order diffracted beams at the level of the wafer W to create an image of the line pattern MP at highest possible resolution and process window (i.e., usable depth of focus in combination with tolerable exposure dose deviations). In some embodiments, astigmatism aberration can be reduced by providing radiation poles (not shown) in opposite quadrants of the illumination system pupil IPU. Further, in some embodiments, astigmatism aberration can be reduced by blocking the zeroth order beams in the pupil conjugate PPU of the projection system associated with radiation poles in opposite quadrants. This is described in more detail in US 7,511,799 B2, issued Mar. 31, 2009, which is incorporated by reference herein in its entirety.

[0041] With the aid of the second positioner PW and position sensor IF (for example, an interferometric device, linear encoder, or capacitive sensor), the substrate table WT can be moved accurately (for example, so as to position different target portions C in the path of the radiation beam B). Similarly, the first positioner PM and another position sensor (not shown in FIG. IB) can be used to accurately position the mask MA with respect to the path of the radiation beam B (for example, after mechanical retrieval from a mask library or during a scan).

[0042] In general, movement of the mask table MT can be realized with the aid of a long- stroke module (coarse positioning) and a short-stroke module (fine positioning), which form part of the first positioner PM. Similarly, movement of the substrate table WT can be realized using a long-stroke module and a short-stroke module, which form part of the second positioner PW. In the case of a stepper (as opposed to a scanner), the mask table MT can be connected to a short- stroke actuator only or can be fixed. Mask MA and substrate W can be aligned using mask alignment marks Ml, M2, and substrate alignment marks PI, P2. Although the substrate alignment marks (as illustrated) occupy dedicated target portions, they can be located in spaces between target portions (known as scribe-lane alignment marks). Similarly, in situations in which more than one die is provided on the mask MA, the mask alignment marks can be located between the dies.

[0043] Mask table MT and patterning device MA can be in a vacuum chamber V, where an in-vacuum robot IVR can be used to move patterning devices such as a mask in and out of vacuum chamber. Alternatively, when mask table MT and patterning device MA are outside of the vacuum chamber, an out-of-vacuum robot can be used for various transportation operations, similar to the in-vacuum robot IVR. Both the in-vacuum and out-of-vacuum robots need to be calibrated for a smooth transfer of any payload (e.g., mask) to a fixed kinematic mount of a transfer station.

[0044] The lithographic apparatus 100 and 100’ can be used in at least one of the following modes:

[0045] 1. In step mode, the support structure (for example, mask table) MT and the substrate table WT are kept essentially stationary, while an entire pattern imparted to the radiation beam B is projected onto a target portion C at one time (i.e., a single static exposure). The substrate table WT is then shifted in the X and/or Y direction so that a different target portion C can be exposed.

[0046] 2. In scan mode, the support structure (for example, mask table) MT and the substrate table WT are scanned synchronously while a pattern imparted to the radiation beam B is projected onto a target portion C (i.e., a single dynamic exposure). The velocity and direction of the substrate table WT relative to the support structure (for example, mask table) MT can be determined by the (de-)magnification and image reversal characteristics of the projection system PS.

[0047] 3. In another mode, the support structure (for example, mask table) MT is kept substantially stationary holding a programmable patterning device, and the substrate table WT is moved or scanned while a pattern imparted to the radiation beam B is projected onto a target portion C. A pulsed radiation source SO can be employed and the programmable patterning device is updated as required after each movement of the substrate table WT or in between successive radiation pulses during a scan. This mode of operation can be readily applied to maskless lithography that utilizes a programmable patterning device, such as a programmable mirror array.

[0048] Combinations and/or variations on the described modes of use or entirely different modes of use can also be employed.

[0049] In a further embodiment, lithographic apparatus 100 includes an extreme ultraviolet

(EUV) source, which is configured to generate a beam of EUV radiation for EUV lithography. In general, the EUV source is configured in a radiation system, and a corresponding illumination system is configured to condition the EUV radiation beam of the EUV source.

[0050] FIG. 2 shows the lithographic apparatus 100 in more detail, including the source collector apparatus SO, the illumination system IL, and the projection system PS. The source collector apparatus SO is constructed and arranged such that a vacuum environment can be maintained in an enclosing structure 220 of the source collector apparatus SO. An EUV radiation emitting plasma 210 can be formed by a discharge produced plasma source. EUV radiation can be produced by a gas or vapor, for example Xe gas, Li vapor, or Sn vapor in which the very hot plasma 210 is created to emit radiation in the EUV range of the electromagnetic spectrum. The very hot plasma 210 is created by, for example, an electrical discharge causing at least a partially ionized plasma. Partial pressures of, for example, 10 Pa of Xe, Li, Sn vapor, or any other suitable gas or vapor can be required for efficient generation of the radiation. In some embodiments, a plasma of excited tin (Sn) is provided to produce EUV radiation.

[0051] The radiation emitted by the hot plasma 210 is passed from a source chamber 211 into a collector chamber 212 via an optional gas barrier or contaminant trap 230 (in some cases also referred to as contaminant barrier or foil trap), which is positioned in or behind an opening in source chamber 211. The contaminant trap 230 can include a channel structure. Contaminant trap 230 can also include a gas barrier or a combination of a gas barrier and a channel structure. The contaminant trap 230 (or contaminant barrier) further indicated herein at least includes a channel structure.

[0052] The collector chamber 212 can include a radiation collector CO, which can be a so- called grazing incidence collector. Radiation collector CO has an upstream radiation collector side 251 and a downstream radiation collector side 252. Radiation that traverses collector CO can be reflected off a grating spectral filter 240 to be focused in a virtual source point IF. The virtual source point IF is commonly referred to as the intermediate focus, and the source collector apparatus is arranged such that the intermediate focus IF is located at or near an opening 219 in the enclosing structure 220. The virtual source point IF is an image of the radiation emitting plasma 210. Grating spectral filter 240 is used in particular for suppressing infra-red (IR) radiation.

[0053] Subsequently the radiation traverses the illumination system IL, which can include a faceted field mirror device 222 and a faceted pupil mirror device 224 arranged to provide a desired angular distribution of the beam of radiation 221, at the patterning device MA, as well as a desired uniformity of radiation intensity at the patterning device MA. Upon reflection of the beam of radiation 221 at the patterning device MA, held by the support structure MT, a patterned beam 226 is formed and the patterned beam 226 is imaged by the projection system PS via reflective elements 228, 229 onto a substrate W held by the wafer stage or substrate table WT.

[0054] More elements than shown can generally be present in illumination optics unit IL and projection system PS. The grating spectral filter 240 can optionally be present, depending upon the type of lithographic apparatus. Further, there can be more mirrors present than those shown in the FIG. 2, for example there can be one to six additional reflective elements present in the projection system PS than shown in FIG. 2.

[0055] Collector optic CO, as illustrated in FIG. 2, is depicted as a nested collector with grazing incidence reflectors 253, 254, and 255, just as an example of a collector (or collector mirror). The grazing incidence reflectors 253, 254, and 255 are disposed axially symmetric around an optical axis O and a collector optic CO of this type is preferably used in combination with a discharge produced plasma source, often called a DPP source.

[0056] Exemplary Lithographic Cell

[0057] FIG. 3 shows a lithographic cell 300, also sometimes referred to a lithocell or cluster, according to some embodiments. Lithographic apparatus 100 or 100’ can form part of lithographic cell 300. Lithographic cell 300 can also include one or more apparatuses to perform pre- and post-exposure processes on a substrate. Conventionally these include spin coaters SC to deposit resist layers, developers DE to develop exposed resist, chill plates CH, and bake plates BK. A substrate handler, or robot, RO picks up substrates from input/output ports I/Ol, 1/02, moves them between the different process apparatuses and delivers them to the loading bay LB of the lithographic apparatus 100 or 100’. These devices, which are often collectively referred to as the track, are under the control of a track control unit TCU, which is itself controlled by a supervisory control system SCS, which also controls the lithographic apparatus via lithography control unit LACU. Thus, the different apparatuses can be operated to maximize throughput and processing efficiency.

[0058] Exemplary Substrate Table

[0059] FIG. 4 shows a perspective schematic of a substrate stage 400, according to some embodiments. In some embodiments, substrate stage comprises a substrate table 402, a support block 404, and one or more sensor structures. In some embodiments, substrate table 402 comprises a clamp to hold a substrate 408 (e.g., an electrostatic clamp). In some embodiments, each of one or more sensor structures 406 comprises a transmission image sensor (TIS) plate. The TIS plate is a sensor unit that comprises one or more sensors and/or markers for use in a TIS sensing system used for accurate positioning of the wafer relative to the position of a projection system (e.g., projection system PS, FIG. 1) and a mask (e.g., mask MA, FIG. 1) of a lithographic apparatus (e.g., lithographic apparatus 100, FIG. 1). TIS plates are shown here for illustration purposes. Embodiments herein are not limited to a particular sensor. Substrate table 402 is disposed on support block 404. One or more sensor structures 406 are disposed on support block 404. In some embodiments, substrate 408 is disposed on substrate table 402 when substrate stage 400 supports substrate 408.

[0060] Exemplary Substrate Table

[0061] The tables mentioned above (e.g., wafer table WT in FIGS. 1A and IB, substrate table 402 in FIG. 4) can have flatness tolerances that are only a few tens of microns. Wafers, being relatively thin (e.g., < 1 mm thick) compared to a width of its surface area (e.g., > 100 mm), are particularly sensitive to unevenness of the substrate table. A protrusion on the substrate table in the order of a few tens of microns can warp a substrate enough to adversely impact subsequent lithographic and metrology processes performed on the substrate— after all, critical dimensions of features in a semiconductor device can approach the sub-nanometer range.

[0062] Substrate tables are typically coated with hard alloys (e.g., chromium nitride, titanium nitride, and the like) in order to protect the surface of the table. The coating decreases maintenance requirements and extends the life of the component. In order to achieve the flatness tolerance required by lithographic and metrology processes, the substrate table is subjected to one or more flattening/polishing processes. One example of a flattening procedure is ion beam flattening (IBF). Some issues with using IBF include length of process (e.g., several days over multiple passes) and ion beam diameter. The ion beam diameter may not be small enough to be used on microscopic projections on a table’s surface that are in the order of a few tens of microns. Embodiments of the present disclosure provide micromanipulator structures and operations to remove microscopic projections quickly and precisely, saving on costs due to fabrication and maintenance time. The micromanipulator structures and operations can also be altered for precise deposition of materials, as opposed to removal.

[0063] FIG. 5 shows a schematic of a micromanipulator device 500, according to some embodiments. In some embodiments, micromanipulator device 500 comprises a stage 502, a metrology apparatus 504, a material removal device 506, and an actuator 508. Metrology apparatus 504 comprises a radiation source 510, an optical system 512, and a detector 514. Material removal device 506 comprises an elongate element 516 and a sharp element 518. In some embodiments, sharp element 518 is disposed at an end of elongate element 516. Material removal device 506 is supported by actuator 508. In some embodiments, actuator 508 can support material removal device 506 in a cantilever arrangement. A connection between material removal device 506 and actuator 508 can comprise an articulation structure.

[0064] In some embodiments, radiation source 510 generates radiation 520. Stage 502 can support an object 522. Object 522 can be, for example, a wafer stage, table, clamp, and the like. A portion 524 of object 522 can be projected from a flat surface (e.g., a surface for supporting a wafer) of object 522. Portion 524 can be, for example, at least a part of a burl or a bubble that has randomly formed during a fabrication process (e.g., a coating process) or some other micro imperfection. Optical system 512 directs radiation 520 toward object 522. Radiation that is scattered by object 522 and/or portion 524 is received by detector 514. Detector 514 generates and outputs data based on the received radiation. The data comprises a position of portion 524. In some embodiments, detector 514 comprises an image capture device (e.g., a camera). In this scenario, the data further comprises an image of object 522 and/or portion 524.

[0065] In order to precisely target micro-imperfections on object 522, embodiments of the present disclosure employ actuators with high precision of motion. In some embodiments, a smallest movement step of actuator 508 can move material removal device 506 less than approximately 1 micron. In some embodiments, a smallest movement step of actuator 508 can move material removal device 506 less than approximately 0.5 micron. In some embodiments, a smallest movement step of actuator 508 can move material removal device 506 less than approximately 0.1 micron. [0066] In some embodiments, actuator 508 can move material removal device 506 so that sharp element 518 is disposed at the position of portion 524. Using actuator 508, material removal device 506 can exert a force on portion 524 with sharp element 518 to dislodge portion 524 from object 522. Portion 524 comprises the same material as the flat parts of the surface of object 522 (e.g., the material of a surface coating). For example, at least part of object 522 and portion 524 can comprise chromium nitride, titanium nitride, diamond-like carbon, silicon, or silicon carbide. In this scenario, the force exerted by sharp element 518 on portion 524 is sufficient to dislodge chromium nitride or titanium nitride. Since coating materials like chromium nitride is rather hard, a strong force can dent or otherwise damage sharp element 518. Therefore, in some embodiments, sharp element 518 comprises tungsten, tungsten carbide, diamond, ruby, or other robust material.

[0067] As noted above, projections that have a small enough size can cause difficulties when using IBF methods. Embodiments in the present disclosure can be used to remove small projections of an object. For example, in some embodiments, a dimension of portion 524 is less than approximately 200 microns. In some embodiments, a dimension of portion 524 is less than approximately 100 microns. In some embodiments, a dimension of portion 524 is less than approximately 50 microns. In some embodiments, a dimension of portion 524 is less than approximately 20 microns.

[0068] Accordingly, micromanipulator device 500 can be used to pinpoint and efficiently remove trace micro-imperfections that may have been leftover by other flattening processes (e.g., IBF). Embodiments of the present disclosure can be applicable in, e.g., situations where performing an IBF procedure proves too time-consuming for the removal of a scant number of micro-imperfections. The few remnant imperfections still need to be removed because of the precisions demanded by lithographic processes, in the case of wafer tables. Micromanipulator device 500 can fulfill this need without the need of lengthy flattening procedures.

[0069] With some alterations, micromanipulator device 500 can be used for precise deposition of materials, such as dispensing a droplet of bonding agent (e.g., micro-repairs, mending). In some embodiments, material removal device 506 can be replaced with a material dispensing device 526. Material dispensing device 526 comprises an elongate conduit 528 and a dispensing end 530. Dispensing end 530 is disposed at an end of elongate conduit 528. In some embodiments, material dispensing device 526 is supported by actuator 508. The relationship and interactions between material dispensing device 526 and actuator 508 are the same as those described above between material removal device 506 and actuator 508. Thus, material dispensing device 526 is capable of the same type of movement and accuracy as described above for material removal device 506. Metrology apparatus 504 and elements therein are used to direct radiation at a target on the object. The target can be a location where repairs are to take place.

[0070] In some embodiments, material dispensing device 526 can be used to dispense a material 532, out dispensing end 530, on object 522. Material 532 can be, for example, a bonding agent used for precision repairs and mends. In some embodiments, a dimension of material 532 dispensed by material dispensing device 526 is less than approximately 100 microns. In some embodiments, a dimension of material 532 dispensed by material dispensing device 526 is less than approximately 50 microns. In some embodiments, a dimension of material 532 dispensed by material dispensing device 526 is less than approximately 20 microns.

[0071] There can be times when it is necessary to perform measurements on a removed projection of a flat surface, for example, to determine a cause for the formation of the projection during processing of the flat surface. FIG. 6 shows a schematic of a metrology system 600, according to some embodiments. In some embodiments, metrology system 600 comprises a stage 602, a radiation source 604, an optical system 606, a detector 608, a material removal device 610, and an actuator 612. Material removal device comprises an elongate element 614 and a sharp element 616. In some embodiments, metrology system 600 further comprises a metrology apparatus 618 and an actuator 620.

[0072] In some embodiments, radiation source 604 generates radiation 622. Stage 602 can support an object 624. Object 624 can be, for example, a wafer stage, table, clamp, and the like. A portion 626 of object 624 can be projected from a flat surface (e.g., a surface for supporting a wafer) of object 624. Portion 626 can be, for example, at least a part of a burl or a bubble that has randomly formed during a fabrication process (e.g., a coating process) or some other micro imperfection. Optical system 606 directs radiation 622 toward object 624. Radiation that is scattered by object 624 and/or portion 626 is received by detector 608. Detector 608 generates and outputs data based on the received radiation. The data comprises a position of portion 626. In some embodiments, detector 608 comprises an image capture device (e.g., a camera). In this scenario, the data further comprises an image of object 624 and/or portion 626. The movement precision of actuator 612 and material removal device 610 are the same as described above for actuator 508 and material removal device 506 (FIG. 5) for reasons discussed above in reference to FIG. 5. [0073] In some embodiments, actuator 612 can move material removal device 610 so that sharp element 616 is disposed at the position of portion 626. Using actuator 612, material removal device 610 can exert a force on portion 626 with sharp element 616 to dislodge portion 626 from object 624. Portion 626 comprises the same material as the flat parts of the surface of object 624 (e.g., the material of a surface coating). For example, at least part of object 624 and portion 626 can comprise chromium nitride, titanium nitride, diamond-like carbon, silicon, or silicon carbide. In this scenario, the force exerted by sharp element 616 on portion 626 is sufficient to dislodge chromium nitride or titanium nitride. Since coating materials like chromium nitride is rather hard, a strong force can dent or otherwise damage sharp element 616. Therefore, in some embodiments, sharp element 616 comprises tungsten, tungsten carbide, diamond, ruby, or other robust material. Possible dimensions of portion 626 are the same as described above for portion 524 (FIG. 5) for reasons discussed above in reference to FIG. 5.

[0074] To perform measurements on portion 626 after it has been dislodged from object

624, in some embodiments, actuator 612 can transfer portion 626 to metrology apparatus 618. In some embodiments, metrology apparatus 618 can determine a property of portion 626 by performing one or more of scanning electron microscopy, tunneling electron microscopy, mass spectrometry, cathodoluminescence spectroscopy, and energy dispersive x-ray spectroscopy. If actuator 612 has difficulty transferring portion 626 directly to metrology apparatus 618 (e.g., due to distance), in some embodiments, actuator 612 can transfer portion 626 to actuator 620. Actuator 620 can comprise a stage and/or manipulator elements (e.g., gripper, robotic arms, and the like) for accepting portion 626 from actuator 612.

[0075] Accordingly, metrology system 600 incorporates structures and functions described in reference to micromanipulator device 500 (FIG. 5) for pinpointing and efficiently removing trace micro-imperfections that may have been leftover by other flattening processes. Metrology system 600 further provides characterization capabilities to analyze micro-imperfections after being dislodged from a parent object.

[0076] In some embodiments, a material removal device with a sharp element can be used for metrology measurements, e.g., when used as a cantilever in conjunction with atomic force microscope (AFM) operations. FIG. 7 shows a system for performing metrology measurements and precision removal of materials, according to some embodiments. In some embodiments, the system comprises a metrology apparatus 700 comprising a stage 702, a radiation source 704, a detector 706, a processor 708, and a cantilever 710 comprising a sharp element 712.

[0077] In some embodiments, stage 702 can support an object 714. Object 714 can be, for example, a wafer stage, table, clamp, and the like. A portion 716 of object 714 can be projected from a flat surface (e.g., a surface for supporting a wafer) of object 714. Portion 716 can be, for example, at least a part of a burl or a bubble that has randomly formed during a fabrication process (e.g., a coating process) or some other micro-imperfection.

[0078] In some embodiments, radiation source 704 generates a radiation 718. Radiation source 704 can direct radiation 718 toward cantilever 710, e.g., onto a reflective portion of cantilever 710. Radiation reflected from cantilever 710 can then be incident on detector 706, that is, detector 706 can receive radiation scattered by cantilever 710. A property of the radiation scattered by cantilever 710 (e.g., propagation direction, spot location on the detector) is based on the state of cantilever 710 (e.g., a deflection state). Detector 704 can be a position-sensitive photodetector. Thus, a change in the state of cantilever 710 (e.g., a deflection) can be sensed by detector 706.

[0079] In some embodiments, cantilever 710 can be deflected as it scans across the surface of object 714. To allow the scanning, a position of object 714 can be adjusted relative to cantilever 710. For example, a position of stage 702, which supports object 714, can be adjusted using one or more actuators capable of translational and/or rotational motion in one, two, or three dimensions. Cantilever 710 can be actuated alternatively or in addition to actuating stage 702. Initially, sharp element 712 of cantilever 710 can be brought into contact with object 714 using a small force such that object 714 is not damaged during the scanning. As a position of object 714 is adjusted, cantilever 710 can experience no further deflection if the surface of object 714 that is scanned is perfectly smooth and flat. However, when sharp element 712 contacts portion 716, cantilever 710 can deflect by an amount that is based on one or more properties of portion 716 (e.g., height, volume). Detector 704 can generate a detection signal based on the received radiation. The detection signal can then be used to determine the one or more properties of portion 716, such as area, height, volume, position, and the like. Processor 708 can receive the detection signal to determine the one or more properties of portion 716. Processor 708 can also generate an image 720 for a visual representation of the one or more properties of portion 716. In this manner, metrology measurements can be performed on object 714. [0080] In some embodiments, metrology apparatus 700 can induce a force between sharp element 712 and portion 716 to dislodge portion 716 from object 714. Using motion of stage 702, sharp element 712 can exert a force on portion 524 to dislodge portion 716 from object 714. Portion 716 comprises the same material as the flat parts of the surface of object 714 (e.g., the material of a surface coating). For example, at least part of object 714 and portion 716 can comprise chromium nitride, titanium nitride, diamond-like carbon, silicon, or silicon carbide. In this scenario, the force exerted by sharp element 712 on portion 716 is sufficient to dislodge chromium nitride or titanium nitride. Since coating materials can be rather hard, a strong force can dent or otherwise damage sharp element 712. Therefore, in some embodiments, sharp element 712 comprises tungsten, tungsten carbide, diamond, ruby, or other robust material.

[0081] In some embodiments, position sensors and actuators can be highly accurate, e.g., down to submicron levels in AFM-type measurements. For example, in some embodiments, a smallest movement step of stage 702 can be less than approximately 100 nm. In some embodiments, a smallest movement step of stage 702 can be less than approximately 50 nm. In some embodiments, a smallest movement step of stage 702 can be less than approximately 10 nm. In some embodiments, a smallest movement step of stage 702 can be less than approximately 1 nm. In some embodiments, a smallest movement step of stage 702 can be less than approximately 0.1 nm. Also, AFM-type measurements are capable of resolving details of a measured object at submicron levels. For example, in some embodiments, a dimension of portion 716 is less than approximately 1000 nm. In some embodiments, a dimension of portion 716 is less than approximately 500 nm. In some embodiments, a dimension of portion 716 is less than approximately 100 nm. In some embodiments, a dimension of portion 716 is less than approximately 50 nm. In some embodiments, a dimension of portion 716 is less than approximately 10 nm. In some embodiments, a dimension of portion 716 is less than approximately 1 nm. In some embodiments, a dimension of portion 716 is less than approximately 0.1 nm. Metrology apparatus 700 can remove portion 716 having the dimensions described above using cantilever 710 and sharp element 712.

[0082] In some embodiments, metrology apparatus 700 can perform metrology measurements and material removal in situ. For example, the system can perform the determining of the one or more properties of portion 716 and the dislodging of portion 716 in situ. Metrology apparatus 700 can achieve in situ functionalities since cantilever 710 functions as both a metrology probe and a material removal device. For example, a process to remove portion 716 from object 714, material from portion 716 can be dislodged using the operations described above. Since sharp element 712 is already in contact with portion 716, an in situ metrology measurement can be performed on portion 716 during the removal operation. If the in situ measurement shows that removal was unsuccessful (e.g., not enough material removed), then a follow-up removal procedure can be executed using updated force parameters based on one or more properties of what remains of portion 716 as determined by the in situ measurement.

[0083] In some embodiments, a laser can be used to ablate or otherwise dislodge undesirable material from a surface. FIG. 8 shows a system 800 for performing metrology measurements and precision removal of materials, according to some embodiments. In some embodiments, system 800 comprises a stage 802, an illumination system 804, a metrology system 806, and a controller 808. Controller 808 can be a processor. Illumination system 804 can comprise a radiation source 810 and one or more light-directing elements 812. One or more light-directing elements 812 can be, for example, actuated mirrors, galvanometers, and the like.

[0084] In some embodiments, stage 802 can support an object 814. Object 814 can be, for example, a wafer stage, table, clamp, and the like. A portion 816 of object 814 can be projected from a flat surface (e.g., a surface for supporting a wafer) of object 814. Portion 816 can be, for example, at least a part of a burl or a bubble that has randomly formed during a fabrication process (e.g., a coating process) or some other micro-imperfection.

[0085] In some embodiments, illumination system 804 generates a beam of radiation 818 using radiation source 810. One or more light-directing elements 812 can direct beam of radiation 818 toward object 814. Radiation source 810 can be a laser device, e.g., C02 laser, yttrium- aluminium-garnet (YAG) laser, and/or variants thereof. Beam of radiation 818 can comprise coherent radiation. Beam of radiation 818 can be pulsed or continuous wave. Beam of radiation 818 can comprise a suitable intensity to ablate the material of portion 816. In some embodiments, portion 816 comprises the same material as the flat parts of the surface of object 814 (e.g., the material of a surface coating). For example, at least part of object 814 and portion 816 can comprise chromium nitride, titanium nitride, diamond-like carbon, silicon, or silicon carbide.

[0086] In some embodiments, the material of object 814 and/or portion 816 can have wavelength-dependent behaviors that affect ablation. For selecting a desirable wavelength for a material, radiation source 810 can have a selectable wavelength. A non-limiting example of a device for selectively adjusting a wavelength is a photon frequency doubler. Beam of radiation 818 can comprise a wavelength in the range of ultraviolet, e.g., 100-400 nm.

[0087] In some embodiments, metrology system 806 can determine one or more properties of portion 816, such as area, height, volume, position, material composition, and the like. Metrology system 806 can comprise an optical measurement device. Some non-limiting examples of optical measurement devices include an interferometer and an optical profiler. In some embodiments, it can be particularly useful if the optical measurement device is capable of determining a height (perpendicular to the surface of object 814) of portion 716. Metrology system 806 can generate input data based on the determined one or more properties of the portion 816. The input data can be received at controller 808. Controller 808 can then use the input data to control the ablation process, for example, by adjusting parameters of illumination system 804 (e.g., beam intensity, pulse energy, repetition rate, average power of the beam, and the like) and positioning portion 816 in the path of beam of radiation 818. The parameters of illumination system 804 can be adjusted to ablate the particular material composition identified by metrology system 806. The parameters of illumination system 804 can be adjusted by controller 808 so as to ablate only the minimum amount of material necessary to achieve a desired flatness conformance for the surface of object 814. This avoids unnecessary heat energy accumulating at the ablation site that can lead to deformations of the surface. In some embodiments, the measurement of object 814 and the removal of portion 816 can be automated by using metrology system 806, controller 808, and illumination system 804 as described above and allowing system 800 to scan the full span of the surface of object 814. That is, system 800 can automate removal of portions of object 814 over the full span of a surface of object 814.

[0088] In some embodiments, the input data can comprise instructions for controller 808 to use for adjusting the parameters of illumination system 804. In some embodiments, the input data can comprise data about detection results of a measurement performed by metrology system 806. In this scenario, the input data can then be processed by controller 808 to generate instructions for adjusting the parameters of illumination system 804.

[0089] In some embodiments, based on the input data, controller 808 can actuate any combination of stage 802, illumination system 804, and one or more light-directing elements 812 to position portion 816 in the path of beam of radiation 818. A position of stage 802 and/or illumination system 804 can be adjusted using one or more actuator capable of translational and/or rotational motion in one, two, or three dimensions.

[0090] In some embodiments, position sensors and actuators can be highly accurate, e.g., down to submicron levels. For example, in some embodiments, a smallest movement step of stage 802 and/or illumination system 804 can be less than approximately 500 nm. In some embodiments, a smallest movement step of stage 802 and/or illumination system 804 can be less than approximately 100 nm. Also, AFM-type measurements are capable of resolving details of a measured object at submicron levels. For example, in some embodiments, a dimension of portion 816 is less than approximately 1000 nm. In some embodiments, a dimension of portion 816 is less than approximately 500 nm. In some embodiments, a dimension of portion 816 is less than approximately 100 nm. System 800 can remove portion 816 having the dimensions described above using laser removal operations described herein.

[0091] In some embodiments, controller 808 can adjust parameters of illumination system

804 such that the power of beam of radiation 818 is just sufficient to sever chemical bonds of portion 816 without fully ablating portion 816. The detached portion 816 can then be cleaned off (e.g., solution bath, gas spray, and the like). Using this technique, heating of object 814 can be further reduced.

[0092] In some embodiments, elements described in reference to a given drawing can be implemented in embodiments described in reference to another drawing. For example, the cantilever measurement system of FIG. 7 can be used as the metrology system in FIG. 8. Doing so can enhance the accuracy of metrology system 806 to that of an AFM system while potentially sacrificing speed of measurement afforded by optical metrology systems. The skilled artisan will appreciate that other combination of elements from two or more drawings can be envisaged.

[0093] FIG. 9 shows method steps for performing functions of described herein, according to some embodiments. At step 902, a beam of radiation can be generated using an illumination system. At step 904, the beam of radiation can be directed toward a portion of an object. At step 906, the portion of the object can be ablated using the beam of radiation. At step 908, one or more properties of the portion of the object can be determined using a metrology system. At step 910, input data can be generated using the metrology system. The one or more properties of the portion of the object can be as described previously (e.g., position, size, height, and the like). At step 912, the input data can be received at a controller. At step 914, the ablating can be controlled based on the input data. For example, the controlling can comprise positioning the portion of the object in the path of the beam of radiation and adjusting a parameter of the illumination system based on the input data based on the input data, wherein the parameter comprises an average power of the beam.

[0094] The method steps of FIG. 9 can be performed in any conceivable order and it is not required that all steps be performed. Moreover, the method steps of FIG. 9 described above merely reflect an example of steps and are not limiting. That is, further method steps and functions may be envisioned based embodiments described in reference to FIGS. 1-8.

[0095] The embodiments may further be described using the following clauses:

1. A system for removing a portion of an object, the system comprising:

a metrology apparatus comprising:

a cantilever comprising a sharp element, wherein the cantilever is configured to deflect when the sharp element contacts the portion of the object;

a stage configured to support the object and to position the object relative to the cantilever; an illumination system configured to generate radiation and direct the radiation toward the cantilever, wherein a property of radiation scattered by the cantilever is based on a deflection state of the cantilever;

a detector configured to receive the scattered radiation and to generate a signal based on the received scattered radiation; and

a processor configured to receive the signal and determine one or more properties of the portion of the object,

wherein the metrology apparatus is configured to induce a force between the sharp element and the portion of the object, using motion of the stage, to dislodge the portion of the object and the force is selected based on a size of the portion of the object.

2. The system of clause 1, wherein the sharp element comprises tungsten, tungsten carbide, diamond, or ruby.

3. The system of clause 1, wherein the object comprises a wafer table and the portion of the object comprises at least part of a burl.

4. The system of clause 1, wherein the portion of the object comprises a material comprising chromium nitride, titanium nitride, diamond-like carbon, silicon, or silicon carbide and the force is sufficient to dislodge the material. 5. The system of clause 1, wherein a smallest movement step of the stage is less than approximately 50 nm.

6. The system of clause 1, wherein a smallest movement step of the stage is less than approximately 10 nm.

7. The system of clause 1, wherein a dimension of the portion of the object is less than approximately 100 nm.

8. The system of clause 1, wherein a dimension of the portion of the object is less than approximately 10 nm.

9. The system of clause 1, wherein the metrology system may perform the determining the one or more properties of the portion of the object and the dislodging the portion of the object in situ.

10. A system for removing a portion of an object, the system comprising:

a stage configured to support the object;

an illumination system configured to generate a beam of radiation and to direct the beam toward the portion of the object to ablate the portion of the object;

a metrology system configured to determine one or more properties of the portion of the object and to generate input data based on the determined one or more properties, wherein the determined one or more properties comprises a position and height of the portion of the object; and

a controller configured to perform operations, the operations comprising:

receiving the input data; and

controlling the ablation, wherein the controlling comprises positioning the portion of the object in the path of the beam and adjusting a parameter of the illumination system based on the input data based on the input data, and the parameter comprises an average power of the beam.

11. The system of clause 10, wherein:

the determined one or more properties comprises a composition of material of the portion of the object;

the material comprises chromium nitride, titanium nitride, diamond-like carbon, silicon; or silicon carbide; and

the controller is further configured to adjust the parameter to ablate the material. 12. The system of clause 10, wherein the object comprises a wafer table and the portion of the object comprises at least part of a burl.

13. The system of clause 10, wherein the beam comprises a wavelength between approximately 100-400 nm.

14. The system of clause 10, wherein the metrology system comprises an interferometer.

15. The system of clause 10, wherein the metrology system comprises an optical profiler.

16. The system of clause 10, wherein the system is configured to automate removal of portions of the object over the full span of a surface of the object.

17. The system of clause 10, wherein the adjusting further comprises adjusting the parameter of the illumination system such that chemical bonds of the portion of the object are severed without fully ablating the portion of the object.

18. A method comprising:

generating a beam of radiation;

directing the beam toward a portion of an object;

ablating the portion of the object using the beam of radiation;

determining one or more properties of the portion of the object using a metrology system; generating input data based on the determined one or more properties using the metrology system, wherein the one or more properties comprises a position and height of the portion of the object;

receiving the input data at a controller;

controlling the ablating, wherein the controlling comprises:

positioning the portion of the object in the path of the beam; and

adjusting a parameter of the illumination system based on the input data based on the input data, wherein the parameter comprises an average power of the beam.

19. The method of clause 18, wherein the metrology system comprises an interferometer.

20. The method of clause 18, wherein the adjusting further comprises adjusting the parameter of the illumination system such that chemical bonds of the portion of the object are severed without fully ablating the portion of the object.

[0096] In some embodiments, a dislodged portion of an object can remain on the surface of the object as a result of any of the dislodging procedures as described above. Those skilled in the art should appreciate dislodged remnant portions of the object can be removed using cleaning techniques (e.g., solution bath, blown off by gas spray, vacuumed, and the like).

[0097] Although specific reference can be made in this text to the use of lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein may have other applications, such as the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat-panel displays, LCDs, thin-film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms“wafer” or“die” herein can be considered as synonymous with the more general terms “substrate” or“target portion”, respectively. The substrate referred to herein can be processed, before or after exposure, in for example a track unit (a tool that typically applies a layer of resist to a substrate and develops the exposed resist), a metrology unit and/or an inspection unit. Where applicable, the disclosure herein can be applied to such and other substrate processing tools. Further, the substrate can be processed more than once, for example in order to create a multi-layer IC, so that the term substrate used herein may also refer to a substrate that already contains multiple processed layers.

[0098] Although specific reference may have been made above to the use of various embodiments in the context of optical lithography, it will be appreciated that such embodiments can be used in other applications, for example imprint lithography, and where the context allows, is not limited to optical lithography. In imprint lithography a topography in a patterning device defines the pattern created on a substrate. The topography of the patterning device can be pressed into a layer of resist supplied to the substrate whereupon the resist is cured by applying electromagnetic radiation, heat, pressure or a combination thereof. The patterning device is moved out of the resist leaving a pattern in it after the resist is cured.

[0099] It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present disclosure is to be interpreted by those skilled in relevant art(s) in light of the teachings herein.

[0100] Further, the terms“radiation,”“beam,” and“light” used herein may encompass all types of electromagnetic radiation, for example, ultraviolet (UV) radiation (for example, having a wavelength l of 365, 248, 193, 157 or 126 nm), extreme ultraviolet (EUV or soft X-ray) radiation (for example, having a wavelength in the range of 5-20 nm such as, for example, 13.5 nm), or hard X-ray working at less than 5 nm, as well as particle beams, such as ion beams or electron beams. Generally, radiation having wavelengths between about 400 to about 700 nm is considered visible radiation; radiation having wavelengths between about 780-3000 nm (or larger) is considered IR radiation. UV refers to radiation with wavelengths of approximately 100-400 nm. Within lithography, the term“UV” also applies to the wavelengths that can be produced by a mercury discharge lamp: G-line 436 nm; H-line 405 nm; and/or, I-line 365 nm. Vacuum UV, or VUV (i.e., UV absorbed by gas), refers to radiation having a wavelength of approximately 100-200 nm. Deep UV (DUV) generally refers to radiation having wavelengths ranging from 126 nm to 428 nm, and in some embodiments, an excimer laser can generate DUV radiation used within a lithographic apparatus. It should be appreciated that radiation having a wavelength in the range of, for example, 5-20 nm relates to radiation with a certain wavelength band, of which at least part is in the range of 5-20 nm.

[0101] The term“substrate” as used herein describes a material onto which material layers are added. In some embodiments, the substrate itself can be patterned and materials added on top of it may also be patterned, or may remain without patterning.

[0102] Although specific reference can be made in this text to the use of disclosed embodiments in the manufacture of ICs, it should be explicitly understood that such an apparatus and/or system has many other possible applications. For example, it can be employed in the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, LCD panels, thin-film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms“reticle,”“wafer,” or“die” in this text should be considered as being replaced by the more general terms“mask,”“substrate,” and “target portion,” respectively.

[0103] While specific embodiments of the present disclosure have been described above, it will be appreciated that the present disclosure can be practiced otherwise than as described. The description is not intended to be limiting.

[0104] It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present disclosure as contemplated by the inventor(s), and thus, are not intended to limit the present disclosure and the appended claims in any way. [0105] The present disclosure has been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.

[0106] The foregoing description of the specific embodiments will so fully reveal the general nature of the present disclosure that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein.

[0107] The breadth and scope of the protected subject matter should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

1. A system for removing a portion of an object, the system comprising:

a metrology apparatus comprising:

2. The system of claim 1, wherein the sharp element comprises tungsten, tungsten carbide, diamond, or ruby.

3. The system of claim 1, wherein the object comprises a wafer table and the portion of the object comprises at least part of a burl.

4. The system of claim 1, wherein the portion of the object comprises a material comprising chromium nitride, titanium nitride, diamond-like carbon, silicon, or silicon carbide and the force is sufficient to dislodge the material.

5. The system of claim 1, wherein a smallest movement step of the stage is less than approximately 50 nm.

6. The system of claim 1, wherein a smallest movement step of the stage is less than approximately 10 nm.

7. The system of claim 1, wherein a dimension of the portion of the object is less than approximately 100 nm.

8. The system of claim 1, wherein a dimension of the portion of the object is less than approximately 10 nm.

9. The system of claim 1, wherein the metrology system may perform the determining the one or more properties of the portion of the object and the dislodging the portion of the object in situ.

10. A system for removing a portion of an object, the system comprising:

a stage configured to support the object;

a controller configured to perform operations, the operations comprising:

receiving the input data; and

11. The system of claim 10, wherein:

the controller is further configured to adjust the parameter to ablate the material.

12. The system of claim 10, wherein the object comprises a wafer table and the portion of the object comprises at least part of a burl.

13. The system of claim 10, wherein the beam comprises a wavelength between approximately 100-400 nm.

14. The system of claim 10, wherein the metrology system comprises an interferometer.

15. The system of claim 10, wherein the metrology system comprises an optical profiler.

16. The system of claim 10, wherein the system is configured to automate removal of portions of the object over the full span of a surface of the object.

17. The system of claim 10, wherein the adjusting further comprises adjusting the parameter of the illumination system such that chemical bonds of the portion of the object are severed without fully ablating the portion of the object.