Burst Statistics Data Aggregation Filter

Abstract

The system includes a laser source configured to generate one or more bursts of laser pulses and a data collection and analysis system configured to receive data related to the one or more bursts of laser pulses from the laser source and determine, based on the received data, that the one or more bursts of laser pulses are for external use. The data collection and analysis system is further configured to determine, based on the received data, whether the one or more bursts of laser pulses are for on-wafer operation or calibration operation.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Application No. 62 / 946,889, entitled BURST STATISTICS DATA AGGREGATION FILTER, filed December 11, 2019, which is incorporated by reference in its entirety herein.

[0002] This disclosure relates to systems and methods for analyzing and utilizing data associated with a laser source. [Background technology]

[0003] A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. Lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such cases, a patterning device, alternatively referred to as a mask or reticle, can be used to generate a circuit pattern to be formed on an individual layer of the IC being formed. This pattern can be transferred onto a target portion (e.g. comprising part of one or several dies) on the substrate (e.g. a silicon wafer). Transfer of the pattern is typically by imaging onto a layer of radiation-sensitive material (photoresist or simply "resist") provided on the substrate. In general, a single substrate will contain a network of adjacent target portions which are successively patterned. Conventional lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing the entire pattern onto the target portion in one go, and so-called 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 substrate parallel or anti-parallel to the 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] Laser sources may be used in lithographic apparatuses to generate illumination radiation, for example to illuminate a patterning device and expose a substrate. Laser sources and lithographic apparatuses may generate large amounts of data. Thus, there is a need for systems and methods for aggregating, clustering, and analyzing data related to the laser source in order to understand and control the operation of the laser source and / or the lithographic apparatus. Summary of the Invention

[0005]

[0005] This disclosure describes embodiments of systems and methods for aggregating and analyzing data related to laser sources.

[0006]

[0006] One aspect of the present disclosure provides a system including a laser source configured to generate a burst of one or more laser pulses and a data collection and analysis system. The data collection and analysis system is configured to receive data related to the burst of one or more laser pulses from the laser source and determine, based on the received data, that the burst of one or more laser pulses is for external use. The data collection and analysis system is further configured to determine, based on the received data, whether the burst of one or more laser pulses is for an on-wafer operation or a calibration operation.

[0007] In some embodiments, the data collection and analysis system is configured to determine from the received data an energy control mode (ECM) value associated with the burst of one or more laser pulses and compare the determined ECM value to a first ECM value. In response to the determined ECM value being different from the first ECM value, the data collection and analysis system is configured to determine that the burst of one or more laser pulses is for external use.

[0008] In some embodiments, the data collection and analysis system is further configured to determine a number of bursts within the one or more bursts of laser pulses. In response to determining that the one or more bursts of laser pulses includes a burst, the data collection and analysis system is configured to determine that the burst of one laser pulse is for a calibration operation.

[0009]

[0009] In some embodiments, the data collection and analysis system is further configured to apply a calibration category test to the received data in response to determining that a burst of one or more laser pulses includes multiple bursts rather than just one burst.

[0010]

[0010] In some embodiments, in response to the calibration category test being satisfied, the data collection and analysis system is further configured to determine that a last burst of the one or more bursts is for a calibration operation and to determine that other bursts of the one or more bursts are for on-wafer operations.

[0011]

[0011] In some embodiments, in response to a calibration category test not being satisfied, the data collection and analysis system is further configured to determine that one or more bursts are for on-wafer operation.

[0012]

[0012] In some embodiments, the data collection and analysis system is further configured to generate the first corrected data by excluding data associated with a first burst and a last burst of the one or more bursts from the received data. The data collection and analysis system is further configured to generate the second corrected data by excluding data associated with a burst having a maximum inter-burst interval (IBI) value from the first corrected data. The data collection and analysis system is further configured to generate an average IBI value based on the IBI values ​​in the second corrected data, generate a standard deviation value based on the IBI values ​​in the second corrected data, and generate an IBI threshold value based on the average IBI value, the standard deviation value, and the IBI parameter.

[0013] In some embodiments, the data collection and analysis system is further configured to determine that a calibration category test is satisfied in response to an IBI value associated with the last burst being greater than an IBI threshold and a pulses per burst (PPB) associated with the last burst being greater than a PBB threshold or a high voltage command variation (HVV) associated with the last burst being greater than an HVV threshold. In response to determining that a calibration category test is satisfied, the data collection and analysis system is further configured to determine that a last burst of the one or more bursts is for a calibration operation and that other bursts of the one or more bursts are for an on-wafer operation.

[0014] In some embodiments, the data collection and analysis system is further configured to determine that a first portion of the one or more bursts is for a calibration operation and to determine that a second portion of the one or more bursts is for an on-wafer operation. The data collection and analysis system is further configured to determine, from the received data, one or more metrics of the second portion of the one or more bursts using data related to the second portion of the one or more bursts.

[0015] In some embodiments, the one or more bursts include a calibration burst used for a calibration operation and one or more on-wafer bursts used for an on-wafer operation. The calibration burst includes a characteristic that differentiates the calibration burst from the one or more on-wafer bursts. The data collection and analysis system is configured to use the characteristic of the calibration burst to distinguish the calibration burst from the on-wafer burst.

[0016]

[0016] In some embodiments, the data collection and analysis system is further configured to assign a wafer identifier to the calibration burst.

[0017] In some embodiments, the one or more bursts include a first calibration burst used for a calibration operation, a second calibration burst used for a second calibration operation, and one or more on-wafer bursts used for an on-wafer operation. The first calibration burst includes a first feature that differentiates the first calibration burst from the one or more on-wafer bursts, and the second calibration burst includes a second feature that differentiates the second calibration burst from the one or more on-wafer bursts. The data collection and analysis system is configured to distinguish the first and second calibration bursts from the one or more on-wafer bursts using the first feature of the first calibration burst and the second feature of the second calibration burst.

[0018]

[0018] Another aspect of the present disclosure provides a method that includes receiving data from a laser source at a data collection and analysis system related to a burst of one or more laser pulses generated by the laser source. The method further includes determining that the burst of one or more laser pulses is for external use based on the data received by the data collection and analysis system. The method also includes determining whether the burst of one or more laser pulses is for an on-wafer operation or a calibration operation based on the data received by the data collection and analysis system.

[0019]

[0019] Another aspect of the present disclosure provides a lithographic apparatus comprising an illumination system for conditioning a radiation beam and a projection system for projecting a pattern imparted to the radiation beam onto a substrate. The illumination system comprises a laser source configured to generate one or more bursts of laser pulses and a data collection and analysis system. The data collection and analysis system is configured to receive data related to the one or more bursts of laser pulses from the laser source and determine, based on the received data, that the one or more bursts of laser pulses are for external use. The data collection and analysis system is further configured to determine, based on the received data, whether the one or more bursts of laser pulses are for an on-wafer operation or a calibration operation.

[0020]

[0020] Another aspect of the present disclosure provides a non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform operations including receiving data from a laser source related to a burst of one or more laser pulses generated by the laser source, determining based on the received data that the burst of one or more laser pulses is for external use, and determining based on the received data whether the burst of one or more laser pulses is for an on-wafer operation or a calibration operation.

[0021]

[0021] Further features and structure and operation of various embodiments are described in detail below with reference to the accompanying drawings. It should be 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 those skilled in the art based on the teachings contained herein. [Brief description of the drawings]

[0022]

[0022] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate the present disclosure and, together with the description, serve to further explain the principles of embodiments of the present disclosure and to enable those skilled in the art to make and use embodiments of the present disclosure.

[0023] [Figure 1A] 1 is a schematic diagram of a reflective lithographic apparatus according to an embodiment; [Figure 1B]

[0024] 1 is a schematic diagram of a transmission lithographic apparatus according to an embodiment; [Diagram 2]

[0025] 1 is a more detailed schematic diagram of a reflective lithographic apparatus according to an embodiment; [Diagram 3]

[0026] 1 is a schematic diagram of a lithographic cell according to an embodiment; [Figure 4A]

[0027] 1 shows a schematic of a laser source and a data collection and analysis system according to some embodiments of the present disclosure. [Figure 4B]

[0028] 1 illustrates an example graph showing example classifications according to some embodiments of the present disclosure. [Figure 4C]

[0028] Figure 1 shows an example graph illustrating an example classification according to some embodiments of the present disclosure. [Figure 4D]

[0028] Figure 1 shows an example graph illustrating an example classification according to some embodiments of the present disclosure. [Diagram 5]

[0029] FIG. 1 illustrates an example functional block diagram illustrating an example system for implementing a data collection and analysis system according to some embodiments of the present disclosure. [Figure 6]

[0030] 1 illustrates an exemplary method for determining and classifying a burst of one or more laser pulses according to some embodiments of the present disclosure. [Figure 7A]

[0031] 1 is a flowchart illustrating a method for determining and classifying one or more bursts as an on-wafer burst or a calibration burst according to some embodiments of the present disclosure. [Figure 7B]1 is a flowchart illustrating a method for determining and classifying one or more bursts as an on-wafer burst or a calibration burst according to some embodiments of the present disclosure. [Figure 8]

[0032] 1 is an exemplary computer system for implementing some embodiments of the present disclosure, or portions thereof.

[0024]

[0033] The features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the drawings, in which like reference numerals identify corresponding elements throughout. In the drawings, like reference numerals generally indicate identical, functionally similar, and / or structurally similar elements. Moreover, the leftmost digit(s) of a reference number generally identifies the drawing in which the reference number first appears. Unless otherwise indicated, the drawings provided throughout this disclosure should not be construed as drawings to scale. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025]

[0034] This specification discloses one or more embodiments incorporating features of the present invention. The disclosed embodiment or embodiments merely exemplify the present invention. The scope of the disclosure is not limited to the disclosed embodiment or embodiments. The breadth and scope of the disclosure are defined only by the claims and their equivalents.

[0026]

[0035] Reference to one or more described embodiments, and to "one embodiment," "an embodiment," "one exemplary embodiment," and the like, herein indicates that the described embodiment may include a particular feature, structure, or characteristic, but that one or more embodiments may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, 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 of ordinary skill in the art to implement such feature, structure, or characteristic in connection with other embodiments, whether or not explicitly described.

[0027]

[0036] Spatially relative terms such as "beneath," "below," "lower," "above," "on," "upper," and the like, may be used herein to facilitate describing the relationship of one element or feature to another element or features, as shown in the figures. The 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 otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may be interpreted accordingly.

[0028]

[0037] The term "about" as used herein refers to a given quantity value that may vary based on a particular technique. Based on a particular technique, the term "about" may refer to a given quantity value that may vary, for example, within 10-30% of the value (e.g., ±10%, ±20%, or ±30% of the value).

[0029]

[0038] The embodiments of the present disclosure may be implemented in hardware, firmware, software, or any combination thereof. The embodiments of the present disclosure may also be implemented as instructions stored on a machine-readable medium that may be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form 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, acoustic, or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.), and others. Furthermore, firmware, software, routines, and / or instructions may be described herein as performing certain operations. However, it will be appreciated that such description is merely for convenience and that such operations may actually result from a computing device, processor, controller, or other device executing firmware, software, routines, instructions, etc.

[0030]

[0039] Before describing such embodiments in detail, it will be useful to present an example environment in which embodiments of the present disclosure can be implemented.

[0031]

[0040] Exemplary Lithography System

[0041] 1A and 1B are schematic diagrams of lithographic apparatus 100 and lithographic apparatus 100', respectively, in which embodiments of the present invention may be implemented. Lithographic apparatus 100 and lithographic apparatus 100' respectively comprise the following: an illumination system (illuminator) IL configured to condition a radiation beam B (e.g. deep ultraviolet radiation (DUV) or extreme ultraviolet radiation (EUV)), a support structure (e.g. mask table) MT configured to support a patterning device (e.g. mask, reticle, or dynamic patterning device) MA and connected to a first positioner PM configured to accurately position the patterning device MA, and a substrate holder such as a table (e.g. wafer table) WT configured to hold a substrate (e.g. resist coated wafer) W and connected to a second positioner PW configured to accurately position the substrate W. Lithographic apparatus 100 and 100' also comprise a projection system PS configured to project a pattern imparted to the radiation beam B by the patterning device MA onto a target portion C (e.g. comprising one or more dies) of the substrate W. In lithographic apparatus 100, the patterning device MA and projection system PS are reflective. In lithographic apparatus 100', the patterning device MA and projection system PS are transmissive.

[0032]

[0042] The illumination system IL may 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.

[0033]

[0043] The support structure MT holds the patterning device MA in a manner that depends on conditions such as an orientation of the patterning device MA relative to a reference frame, the design of at least one of the lithographic apparatuses 100 and 100', and whether or not the patterning device is held in a vacuum environment. The support structure MT may 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 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.

[0034]

[0044] The term "patterning device" MA should be interpreted broadly to refer to any device that can be used to impart a pattern to a radiation beam B in its cross-section to create a pattern in a target portion C of a substrate W. The pattern imparted to the radiation beam B may correspond to a particular functional layer in a device being created in the target portion C to form an integrated circuit.

[0035]

[0045] Patterning device MA may be transmissive (as in lithographic apparatus 100' of FIG. 1B) 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 masks, 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 to a radiation beam B that is reflected by the matrix of small mirrors.

[0036]

[0046] The term "projection system" PS may include any type of projection system including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems, or any combination thereof, appropriate to the exposure radiation used, or other factors such as the use of an immersion liquid or the use of a vacuum on the substrate W. A vacuum environment may be used for extreme ultraviolet (EUV) or electron beam radiation, as other gases may absorb too much radiation or electrons. A vacuum environment may therefore be provided throughout the beam path using a vacuum wall and vacuum pumps.

[0037]

[0047] Lithographic apparatus 100 and / or lithographic apparatus 100' may be of a type having two (dual stage) or more substrate tables WT (and / or two or more mask tables). In such a "multi-stage" machine, the additional substrate tables WT may be used in parallel, or preparation steps may be carried out on one or more other tables whilst one or more substrate tables WT are being used for exposure. In some circumstances the additional tables may not be substrate tables WT.

[0038]

[0048] The lithographic apparatus 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, such as water, so as to fill a space between the projection system and the substrate. Immersion liquids may 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. As used herein, the term "immersion" does not mean that a structure such as the substrate must be submerged in liquid, but rather that a liquid is present between the projection system and the substrate during exposure.

[0039]

[0049] 1A and 1B, the illuminator IL receives a radiation beam from a radiation source SO. The source SO and the lithographic apparatus 100, 100' may be separate physical entities, for example if the source SO is an excimer laser. In this case, 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 via a beam delivery system BD (FIG. 1B), for example with suitable directing mirrors and / or beam expanders. In other cases, the source SO may be an integral part of the lithographic apparatus 100, 100', for example if the source SO is a mercury lamp. The source SO and the illuminator IL, together with the beam delivery system BD, if required, may be referred to as a radiation system.

[0040]

[0050] The illuminator IL may comprise an adjuster AD (Figure 1B) for adjusting the angular intensity distribution of the radiation beam. Generally, at least the outer and / or inner radial extent (commonly referred to as "σ-outer" and "σ-inner", respectively) of the intensity distribution in a pupil plane of the illuminator may be adjusted. In addition, the illuminator IL may comprise various other components, such as an integrator IN and a condenser CO (Figure 1B). The illuminator IL can be used to adjust the radiation beam B to obtain a desired uniformity and intensity distribution in its cross-section.

[0041]

[0051] Referring to FIG. 1A, a radiation beam B is incident on a patterning device (e.g. mask) MA, which is held on a support structure (e.g. mask table) MT, and is patterned by the patterning device MA. In the lithographic apparatus 100, the radiation beam B is reflected from the patterning device (e.g. mask) MA. After being reflected from the patterning device (e.g. mask) MA, the radiation beam B passes through a projection system PS. The projection system PS focuses the radiation beam B onto a target portion C of a substrate W. With the aid of a second positioner PW and a position sensor IF2 (e.g. an interferometric device, a linear encoder, or a capacitive sensor), the substrate table WT can be accurately moved (e.g. to position a different target portion C in the path of the radiation beam B). Similarly, a first positioner PM and another position sensor IF1 can be used to accurately position the patterning device (e.g. mask) MA with respect to the path of the radiation beam B. Mask alignment marks M1, M2 and substrate alignment marks P1, P2 may be used to align the patterning device (eg mask) MA and substrate W.

[0042]

[0052] Referring to Figure 1B, the radiation beam B is incident on a patterning device (e.g. mask MA), which is held on a support structure (e.g. mask table MT), and is patterned by the patterning device. After traversing the mask MA, the radiation beam B passes through a projection system PS, which focuses the beam onto a target portion C of a substrate W. The projection system has a pupil PPU that is conjugate with the illumination system pupil IPU. A portion of the radiation originates from the intensity distribution in the illumination system pupil IPU and traverses the mask pattern without being subject to diffraction at the mask pattern, creating an image of the intensity distribution in the illumination system pupil IPU.

[0043]

[0053] The projection system PS projects an image MP' of the mask pattern MP. The image MP' is formed on a photoresist layer coated on the substrate W by diffracted beams generated from the mark pattern MP by radiation from the intensity distribution. For example, the mask pattern MP may include an array of lines and spaces. Non-zero order diffraction of radiation at the array generates stimulated diffracted beams redirected perpendicular to the lines. The non-diffracted beams (i.e. the so-called zero order diffracted beams) traverse the pattern without changing their propagation direction. The zero order diffracted beams traverse an upper lens or an upper lens group of the projection system PS upstream of the conjugate pupil PPU of the projection system PS and reach the conjugate pupil PPU. The part of the intensity distribution in the plane of the conjugate pupil PPU associated with the zero order diffracted beam is an image of the intensity distribution in the illumination system pupil IPU of the illumination system IL. The aperture device PD is arranged, for example, in a plane or substantially in a plane including the conjugate pupil PPU of the projection system PS.

[0044]

[0054] The projection system PS is arranged to capture not only the zeroth order diffracted beam but also the first or higher order diffracted beams (not shown) by means of a lens or lens group L. In an embodiment, dipole illumination can be used to image a line pattern extending in a direction perpendicular to the line in order to take advantage of the resolution enhancing effect of dipole illumination. For example, a first order diffracted beam interferes with a corresponding zeroth order diffracted beam at the level of the wafer W to create an image of the line pattern MP at the highest possible resolution and process window (i.e. usable depth of focus in combination with an acceptable exposure dose deviation). In some embodiments, astigmatism may be reduced by providing a pole (not shown) in the opposite quadrant of the illumination system pupil IPU. Furthermore, in some embodiments, astigmatism may be reduced by blocking the zeroth order beam in a conjugate pupil PPU of the projection system associated with the pole in the opposite quadrant.

[0045]

[0055] With the aid of a second positioner PW and a position sensor IF (e.g. an interferometric device, a linear encoder or a capacitive sensor), the substrate table WT can be accurately moved (e.g. to position a different target portion C in the path of the radiation beam B). Similarly, the mask MA can be accurately positioned with respect to the path of the radiation beam B using the first positioner PM and a further position sensor (not shown in FIG. 1B ) (e.g. after mechanical removal of the mask library or during a scan).

[0046]

[0056] In general, movement of the mask table MT may 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 may 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 may be connected to a short-stroke actuator only, or may be fixed. The mask MA and substrate W may be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2. The substrate alignment marks (as shown) occupy dedicated target portions, but may be located in spaces between the 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 may be located between the dies.

[0047]

[0057] The mask table MT and patterning device MA may be in a vacuum chamber V. An in-vacuum robot IVR can be used to move the patterning device, such as a mask, in and out of the vacuum chamber. Alternatively, if the mask table MT and patterning device MA are outside the vacuum chamber, an ex-vacuum robot can be used for various transport operations, similar to the in-vacuum robot IVR. Both the in-vacuum and ex-vacuum robots need to be calibrated for smooth movement of any payload (e.g. a mask) to the fixed kinematic mount of the transfer station.

[0048]

[0058] The depicted lithographic apparatus 100 and 100' can be used in at least one of the following modes:

[0049]

[0059] 1. In step mode, the support structure (e.g. mask table) MT and substrate table WT are kept essentially stationary, while an entire pattern imparted to the radiation beam B is projected onto a target portion C in one go (i.e. a single static exposure), and the substrate table WT is then moved in the X and / or Y direction so that a different target portion C can be exposed.

[0050]

[0060] 2. In scan mode, the support structure (e.g. 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 (e.g. mask table) MT can be determined by the (de-)magnification and image reversal characteristics of the projection system PS.

[0051]

[0061] 3. In another mode, the support structure (e.g. mask table) MT is held 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 used and the programmable patterning device is updated as required after each movement of the substrate table WT, or between successive radiation pulses during a scan. This mode of operation is readily applicable to maskless lithography using a programmable patterning device such as a programmable mirror array.

[0052]

[0062] Combinations and / or variations on the above described modes of use or entirely different modes of use may also be employed.

[0053]

[0063] In a further embodiment, the lithographic apparatus 100 comprises an extreme ultraviolet (EUV) source configured to generate a beam of EUV radiation for EUV lithography. Typically 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.

[0054]

[0064] FIG. 2 shows the lithographic apparatus 100 in more detail, comprising a source collector apparatus SO, an illumination system IL, and a projection system PS. The source collector apparatus SO is constructed and arranged to maintain a vacuum environment in an enclosure 220. The source collector apparatus 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, for example Xe gas, Li vapor, or Sn vapor, in which an EUV radiation-emitting plasma 210 is generated, emitting radiation in the EUV range of the electromagnetic spectrum. The at least partially ionized EUV radiation-emitting plasma 210 may be generated, for example, by an electric discharge or a laser beam. Efficient generation of radiation may require, for example, a partial pressure of 10 Pa of Xe, Li, Sn vapor, or any other suitable gas or vapor. In an embodiment, an excited tin (Sn) plasma is provided to generate the EUV radiation.

[0055]

[0065] Radiation emitted by the EUV radiation emitting plasma 210 is delivered from the source chamber 211 into the collector chamber 212 via an optional gas barrier or contaminant trap 230 (sometimes also referred to as a contaminant barrier or foil trap) located in or behind an opening in the source chamber 211. The contaminant trap 230 may include a channel structure. The contaminant trap 230 may include a gas barrier or a combination of a gas barrier and a channel structure. The contaminant trap or contaminant barrier 230 further illustrated herein includes at least a channel structure.

[0056]

[0066] The collector chamber 212 may include a radiation collector CO, which may be a so-called grazing incidence collector. The radiation collector CO has an upstream radiation collector side 251 and a downstream radiation collector side 252. Radiation traversing the collector CO may be reflected off a grating spectral filter 240 and focused into a virtual source point IF. The virtual source point IF is commonly referred to as an intermediate focus, and the source collector arrangement is positioned such that the intermediate focus IF is located at or near the opening 219 of the enclosure structure 220. The virtual source point IF is an image of the radiation emitting plasma 210. The grating spectral filter 240 is used in particular to suppress infrared (IR) radiation.

[0057]

[0067] The radiation subsequently traverses the illumination system IL, which may comprise a faceted field mirror device 222 and a faceted pupil mirror device 224 arranged to provide a desired angular distribution of the radiation beam 221 at the patterning device MA and to provide a desired radiation intensity uniformity at the patterning device MA. Upon reflection of the radiation beam 221 off the patterning device MA, which is held by the support structure MT, a patterned beam 226 is formed which is imaged by the projection system PS via reflective elements 228, 229 onto the substrate W held by a wafer stage or substrate table WT.

[0058]

[0068] Generally, there may be more elements in the illumination optics unit IL and projection system PS than shown. A grating spectral filter 240 may be optionally present depending on the type of lithographic apparatus. Furthermore, there may be more mirrors than shown in Figure 2, for example there may be 1 to 6 additional reflective elements in the projection system PS compared to those shown in Figure 2.

[0059]

[0069] 2 is shown as a nested collector with grazing incidence reflectors 253, 254, and 255, just as an example of a collector (or collector mirror). Grazing incidence reflectors 253, 254, and 255 are arranged axially symmetrically about optical axis O, and this type of collector system CO is suitable for use in combination with a discharge produced plasma source, often referred to as a DPP source.

[0060]

[0070] Exemplary Lithography Cell

[0071] FIG. 3 shows a lithography cell 300, sometimes called a lithocell or cluster. The lithography apparatus 100 or 100′ may form 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 a substrate. Conventionally, these include a spin coater SC for depositing a resist layer, a developer DE for developing the exposed resist, a chill plate CH, and a bake plate BK. A substrate handler, or robot RO, picks up substrates from input / output ports I / O1, I / O2, moves them between the various process apparatus and stations, and delivers them to a loading bay LB of the lithography apparatus 100 or 100′. Collectively, these devices are often referred to as a track, and are under the control of a track control unit TCU. The TCU is itself controlled by a supervisory control system SCS, which also controls the lithography apparatus via a lithography control unit LACU. These various apparatus can thus be operated to maximize throughput and processing efficiency.

[0061]

[0072] Exemplary Data Collection and Analysis System

[0073] FIG. 4A shows a schematic of a laser source 401 and a data collection and analysis system 403 according to some embodiments of the present disclosure. In some embodiments, the laser source 401 can be used as part of or in addition to the source SO of the lithographic apparatus 100 or 100′. In some embodiments, the laser source 401 can be used as part of or in addition to the source SO of the lithographic apparatus of FIG. 2. Additionally or alternatively, the laser source 401 can be used in generating DUV radiation for use in the lithographic apparatus 100 or 100′ or other DUV lithographic apparatus. As shown in FIG. 4A, the laser source 401 can generate a laser 405 for use in the lithographic apparatus. In some embodiments, where the laser source 401 is used as part of or in addition to the source SO of the lithographic apparatus of FIG. 2, the laser source 401 generates a laser 405 that can be used to convert a target material into a plasma that generates EUV radiation that is directed to and used in the lithographic apparatus.

[0062]

[0074] According to some embodiments, the laser source 401 may comprise and / or be communicatively coupled to a data collection and analysis system 403. The data collection and analysis system 403 is configured to receive data 407 from the laser source 401. Additionally or alternatively, the data collection and analysis system 403 may send data and / or control information 409 back to the laser source 401.

[0063]

[0075] According to some embodiments, the data 407 from the laser source 401 may include raw burst data associated with the laser source 401. The raw burst data is data received from the laser source 401 by the data collection and analysis system 403 and represents aggregated pulse-by-pulse data (e.g., streaming data) associated with the laser source 401 present on the laser source 401. In other words, according to some embodiments, the pulse-by-pulse data associated with the laser source 401 may be considered streaming data. According to some embodiments, the streaming data associated with the laser source 401 is pulse level data and may include information regarding the energy control mode, energy level, wavelength, etc. associated with each pulse. This information is provided as exemplary information, and the streaming data associated with the laser source 401 may include other data associated with the laser pulse. In some examples, the streaming data may include one row of data per pulse, with each column of the row including a parameter associated with the pulse. However, the streaming data may also include a collection of other data associated with the laser pulse.

[0064]

[0076] According to some embodiments, the data collection and analysis system 403 is configured to receive data 407 (e.g., raw burst data). In some examples, the raw burst data is burst level data, which is a collection of streaming data for multiple laser pulses of a burst. For example, the raw burst data may include aggregate data such as, but not limited to, maximum, minimum, sliding window average, number of pulses per burst (PPB), high voltage command variation (HVV), etc., of streaming data associated with multiple laser pulses of a burst. In some examples, the raw burst data may include one row of data per burst pulse, with each column of the row including a parameter associated with the burst. However, the raw burst data may also include other collections of data associated with the burst.

[0065]

[0077] According to some embodiments, the data collection and analysis system 403 is configured to analyze the received data 407. This analysis may include, but is not limited to, clustering the data into various groups, generating one or more data subsets, determining one or more metrics (e.g., performance measures) based on the data 407 and / or the data subsets, etc. These operations are provided as exemplary operation(s) of the data collection and analysis system 403. The data collection and analysis system 403 may also be configured to perform additional or other operations on the data 407.

[0066]

[0078] For example, the data collection and analysis system 403 can be configured to generate burst data from the received data 407. In some embodiments, the burst data can include one row per burst and can be a subset of the raw burst data (e.g., data 407). However, the burst data can also include a collection of other data related to the raw burst data. In another embodiment, the data collection and analysis system 403 can be configured to determine burst statistics. For example, the collection and analysis system 403 can generate the burst statistics from the burst data. In some embodiments, the burst statistics can include one or more metrics (e.g., performance metrics) related to the burst data. The metrics can include, but are not limited to, minimum, maximum, average, standard deviation, and / or other metrics. In one embodiment, the burst statistics can include one row per substrate (e.g., wafer) and / or one row per energy control mode (ECM).

[0067]

[0079] According to some embodiments, the data collection and analysis system 403 is configured to classify the data 407 (or a subset of the data 407) into two or more categories. As discussed above, the data 407 may include raw burst data associated with one or more bursts of laser pulses generated by the laser source 401. In some examples, the data collection and analysis system 403 is configured to classify the raw burst data into two or more categories. Additionally or alternatively, the data collection and analysis system 403 is configured to classify the burst data (e.g., a subset of the raw burst data) into two or more categories. Some of the embodiments of this disclosure are discussed with respect to classifying the data 407. However, as discussed above, the classification may be with respect to the data 407 (e.g., the raw burst data) and / or a subset of the data 407 (e.g., the burst data).

[0068]

[0080] According to some embodiments, a first step in classifying the data 407 may include classifying the data 407 based on an energy control mode (ECM) associated with the data 407. The data 407 associated with one or more bursts may indicate whether each burst is generated for external use (e.g., for use in a lithography apparatus, e.g., for use in illuminating / exposing a substrate (e.g., a wafer) in the lithography apparatus) or whether the burst is generated for internal use (e.g., for internal use in the laser source 401, but not for exposure of a substrate). In other words, if the ECM indicates internal use, the lithography apparatus (e.g., a scanner in the lithography apparatus) does not control the energy of the laser pulses in the laser source 401, but the laser source 401 does control the energy of the laser pulses. As a non-limiting example, the data 407 may include an ECM value. The ECM value indicates whether the burst is generated for external use or for internal use.

[0069]

[0081] The data collection and analysis system 403 is configured to determine an ECM value for the data 407 and classify the data 407 using the ECM value. For example, the data collection and analysis system 403 may aggregate blocks of consecutive bursts having the same ECM value. After classifying and aggregating the data 407 into an external use category or an internal use category, the data collection and analysis system 403 may determine one or more metrics (e.g., determine burst statistics) for each block of aggregated bursts. According to some embodiments, the data collection and analysis system 403 is configured to determine one or more metrics (e.g., determine burst statistics) for the blocks of bursts aggregated into the external use category and / or one or more metrics (e.g., determine burst statistics) for the blocks of bursts aggregated into the internal use category.

[0070]

[0082] FIG. 4B illustrates an example graph 420 showing example classifications, according to some embodiments of the disclosure. As shown in FIG. 4B, in one example, the data collection and analysis system 403 can use two ECM values ​​(ECM1 421 and ECM2 423) to classify the data 407. In this example, the graph 420 illustrates an external use block 425 associated with an ECM value of ECM2 423, which indicates data classified in the external use category. In this example, the graph 420 also illustrates an internal use block 427 associated with an ECM value of ECM1 421, which indicates data classified in the internal use category. It should be noted that although two ECM values ​​are discussed in some embodiments of the disclosure, other numbers of ECM values ​​may be used by the data collection and analysis system 403 to classify the data 407.

[0071]

[0083] According to some embodiments, when a burst of laser pulses (e.g., a portion of laser 405) is generated for external use (e.g., the ECM value of data 407 indicates external use), the burst can be used for on-wafer operations or one or more calibration operations. The on-wafer operations can include an exposure operation, such as an operation for illuminating a patterning device in a lithographic apparatus and patterning a radiation beam to generate a pattern on a target portion of a substrate (e.g., a wafer). The one or more calibration operations can include any operation for calibrating the laser source 401 and / or the lithographic apparatus. For example, the one or more calibration operations can include calibrating a laser gain prior to an on-wafer operation. In some examples, the one or more calibration operations can include a sinusoidal calibration (e.g., a calibration using a sine wave). As another example, the one or more calibration operations can include a calibration using / based on one or more wavelengths and / or bandwidths of the laser. However, embodiments of the present disclosure can also include other calibration operations.

[0072]

[0084] According to some embodiments, when a burst of laser pulses is used for one or more calibration operations, the burst for which the ECM value indicates external use is used. As discussed in more detail below, the data collection and analysis system 403 is configured to distinguish between the burst(s) used for on-wafer operations and the burst(s) used for one or more calibration operations. Thus, the data collection and analysis system 403 is configured to further classify the data in the external use category into an on-wafer operation category and a calibration operation category. In other words, the data collection and analysis system 403 is configured to classify the data 407 into at least three categories: (1) an internal use category, (2) an on-wafer operation category, and (3) a calibration operation category.

[0073]

[0085] In some embodiments, the "on-wafer" category refers to a laser burst operation that indirectly and ultimately involves an exposure operation on a wafer. For example, a burst of laser pulses may excite a target material and convert the solid target material into a plasma that produces EUV radiation. The EUV radiation is directed to a patterning device in a lithography apparatus, where the EUV radiation is patterned to produce a pattern on a target portion of a substrate (e.g., a wafer).

[0074]

[0086] After classifying and aggregating the data 407 into these at least three categories, the data collection and analysis system 403 can determine one or more metrics (e.g., performance measures) for each block of aggregated bursts (e.g., determine burst statistics). According to some embodiments, the data collection and analysis system 403 is configured to determine one or more metrics (e.g., determine burst statistics) for the blocks of bursts aggregated into the internal use category, one or more metrics for the blocks of bursts aggregated into the calibration operation category, and / or one or more metrics for the blocks of bursts aggregated into the on-wafer operation category. In some examples, the burst statistics can include at least three rows per substrate (e.g., wafer). In this example, one row of the burst statistics is associated with the internal use category, another row of the burst statistics is associated with the on-wafer operation category, and one or more other rows of the burst statistics are associated with one or more calibration operations. In some examples, each ECM mode block can have up to two rows. For example, an ECM block associated with the internal use category can have one row. Alternatively, an ECM block associated with the external use category may have one row if there are no bursts in the calibration operation category, may have one row if there is a single burst in the block, or may have two rows if there is an on-wafer burst(s) and a burst(s) in the calibration operation category. In some embodiments, the burst statistics data may be the output of the calibration filter 503 of FIG. 5 and / or the output of the metric generator 505 of FIG. 5.

[0075]

[0087] According to some embodiments, by distinguishing between on-wafer and calibration operation categories, the data collection and analysis system 403 can generate one or more metrics for the block of bursts aggregated into the on-wafer operation category. Thus, by removing data associated with the calibration operation category, the data collection and analysis system 403 can generate one or more metrics that better and accurately represent the block of bursts aggregated into the on-wafer operation category. In other words, the data collection and analysis system 403 can generate performance metric(s) that more accurately represent the exposure data and that the data collection and analysis system 403 can use in monitoring and controlling the laser source 401.

[0076]

[0088] Some embodiments of this disclosure discuss at least three categories, but this disclosure is not limited to these categories. In some embodiments, the calibration operation category can be further divided into two or more subcategories, and the data collection and analysis system 403 can be configured to analyze and aggregate the data 407 into two or more subcategories of the calibration operation category. For example, each one of the two or more subcategories of the calibration operation category can be associated with one calibration operation. According to some embodiments, the data collection and analysis system 403 can be configured to aggregate the data 407 into subcategories associated with the corresponding calibration operation based on one or more parameters associated with the calibration operation. Using the one or more parameters associated with each calibration operation, the data collection and analysis system 403 can aggregate the data 407 into its associated calibration operation subcategory.

[0077]

[0089] According to some embodiments, after analysis, classification, aggregation, and / or generation of one or more metrics of data associated with an on-wafer operational category, the data collection and analysis system 403 can be configured to use the one or more metrics (e.g., data and / or control information 409) for further monitoring and control of the laser source 401. In other words, the data collection and analysis system 403 can generate and use (e.g., by monitoring and controlling the laser source 401) performance metrics (one or more) that more accurately represent the exposure data.

[0078]

[0090] In some embodiments, the data collection and analysis system 403 can be located locally with the laser source 401. Additionally or alternatively, the data collection and analysis system 403 can be located at a central location that receives data from one or more laser sources. In some embodiments, the data collection and analysis system 403 can comprise components that are located locally with the laser source 401 and / or distributed in different geographic locations and communicate with each other using one or more networks.

[0079]

[0091] FIG. 4C illustrates an example graph 430 showing another example classification, according to some embodiments of the disclosure. As shown in FIG. 4C, in one example, the data collection and analysis system 403 can use values ​​of two ECMs (ECM1 421 and ECM2 423) to classify the data 407. In this example, the graph 430 illustrates a block 434 of one or more bursts associated with an ECM value of ECM2 423 indicative of data classified in an on-wafer operation category. In this example, the graph 430 also illustrates an internal block 427 of one or more bursts associated with an ECM value of ECM1 421 indicative of data classified in an internal use category. In this example, the graph 430 further illustrates a burst 436 associated with an ECM value of ECM2 423 indicative of data classified in a calibration operation category.

[0080]

[0092] In some examples, the burst classified in the calibration operation category may be the last burst of the block associated with the ECM value of ECM2 423. In other words, in the example of Figure 4C, burst 436 is the last burst after block of one or more bursts 434. However, embodiments of this disclosure are not limited to this example, and the burst(s) in the on-wafer operation category and the burst(s) in the calibration category may have other numbers and relationships.

[0081]

[0093] 4D illustrates an example graph 440 showing another example classification, according to some embodiments of the disclosure. As shown in FIG. 4D, in one example, the data collection and analysis system 403 can use values ​​of two ECMs (ECM1 421 and ECM2 423) to classify the data 407. In this example, the graph 440 illustrates a block 444 of one or more bursts associated with an ECM value of ECM2 423 indicative of data classified in an on-wafer operation category. In this example, the graph 440 also illustrates an internal block 427 of one or more bursts associated with an ECM value of ECM1 421 indicative of data classified in an internal use category. In this example, the graph 440 further illustrates a burst 446 associated with an ECM value of ECM2 423 indicative of data classified in a calibration operation category.

[0082]

[0094] In some examples, the burst classified in the calibration operation category may be the last burst of the block associated with the ECM value of ECM2 423. In other words, in the example of FIG. 4D, burst 446 is the last burst after block 444. However, embodiments of this disclosure are not limited to this example, and the burst(s) in the on-wafer operation category and the burst(s) in the calibration category may have other numbers and relationships. For example, in the example of FIG. 4D, burst 448 is not a calibration burst, and both block 445 and burst 448 of one or more bursts may be classified in the on-wafer operation category. In this example, burst 449 may be a calibration burst.

[0083]

[0095] 5 is an example functional block diagram illustrating an example system for implementing data collection and analysis system 403, according to some embodiments of the present disclosure. System 500 of FIG. 5 may be and / or may be implemented within data collection and analysis system 403.

[0084]

[0096] System 500 includes a cluster controller 501, a calibration filter 503, a metric generator 505, and tables 507a-507c. It should be noted that the components are shown as example components of system 500, and that system 500 may include fewer components, more components, or other components.

[0085]

[0097] According to some embodiments, cluster controller 501 is configured to receive burst data 502. In some examples, burst data 502 is generated based on data 407 (e.g., raw burst data) arriving from laser source 401 to data collection and analysis system 403, as shown in FIG. 4A. For example, data 407 (e.g., raw burst data) arrives at data collection and analysis system 403 (e.g., system 500) and is aggregated into burst data 502. This aggregation may include discarding some parameters in data 407 according to some embodiments, but the aggregation does not eliminate bursts.

[0086]

[0098] According to some embodiments, the cluster controller 501 is configured to receive burst data 502 associated with the laser source 401. The cluster controller 501 is further configured to classify (e.g., cluster) the burst data 502 and generate burst data block(s) 504. According to some embodiments, the cluster controller 501 is configured to classify the burst data 502 based on an ECM value associated with the burst data 502. The ECM value may indicate whether a burst of one or more laser pulses corresponding to the burst data 502 is generated for external or internal use. The cluster controller 501 is configured to determine an ECM value for the burst data 502 and classify the burst data 502 using the ECM value. For example, if the ECM value indicates that the burst of one or more laser pulses corresponding to the burst data 502 is for internal use, the cluster controller 501 may classify (e.g., cluster) the burst data 502 into an internal category. If the ECM value indicates that the burst of one or more laser pulses is for external use, the cluster controller 501 can classify the burst data 502 into the external category.

[0087]

[0099] For example, when bursts of consecutive laser pulses arrive having the same ECM value, the cluster controller 501 can classify (e.g., cluster) them and store them as a block until the cluster controller 501 determines that the ECM value has changed. Once the cluster controller 501 determines that the ECM value has changed, the block of clusters can be aggregated and stored for internal use or sent to the calibration filter 503 for calibration category testing.

[0088]

[0100] After classification based on the ECM value, the cluster controller 501 may output a burst data block 504. According to some embodiments, the burst data block 504 is a block of burst data associated with one or more bursts classified into an internal use category or an external use category. According to some embodiments, the burst data block 504 is input to a calibration filter 503. In some embodiments, if the burst data block 504 is classified into the internal use category, the calibration filter 503 is configured to output data 506a to the metric generator 505. Alternatively, if the burst data block 504 is classified into the internal use category, the cluster controller 501 may send the burst data block 504 directly to the metric generator 505 as data 506a (e.g., bypassing the calibration filter 503). In other words, if the cluster controller 501 classifies the burst data 502 into the internal use category, the cluster controller 501 can bypass the calibration filter 503 and send the burst data block 504 directly to the metric generator 505 as data 506a. According to some embodiments, the metric generator 505 may generate one or more metrics for the data 506a. In some implementations, the one or more metrics can be stored in a table 507a. In some implementations, the table 507a can be a database in a storage device. In some embodiments, if the cluster controller 501 determines that the burst data 502 should be classified into the internal use category, the cluster controller 501 can send the burst data block 504 directly to the metric generator 505 (without going through the calibration filter 503). Alternatively, the cluster controller 501 can send the burst data block 504 directly to a table (not shown, e.g., different from table 507a) (e.g., bypassing the calibration filter 503 and the metric generator 505).

[0089]

[0101] On the other hand, if the burst data block 504 is classified into the external use category, the calibration filter 503 is configured to further classify the burst data block 504. For example, the calibration filter 503 may determine whether the burst data block 504 indicates that one or more bursts associated with the burst data 502 should be used for on-wafer operations and / or for one or more calibration operations. As discussed in more detail below, the calibration filter 503 is configured to apply a calibration category test to the burst data block 504 that determines whether one or more bursts associated with the burst data 502 should be used for on-wafer operations and / or for one or more calibration operations.

[0090]

[0102] If the calibration filter 503 uses the burst data block 504 to determine that a burst of one or more laser pulses (or a subset of one or more bursts) should be used for on-wafer operation, the calibration filter 503 classifies the burst data block 504 (or a subset of the burst data block 504) into an on-wafer operation category and generates data 506b. The data 506b is sent to a metric generator 505. The metric generator 505 may generate one or more metrics for the data 506b and store them, for example, in a table 507b. In some examples, the table 507b may be a database in a storage device. In some embodiments, the calibration filter 503 may send the burst data block 504 (or a subset of the burst data block 504) directly to a table (not shown, e.g., different from table 507b) (e.g., bypassing the metric generator 505).

[0091]

[0103] If the calibration filter 503 uses the burst data block 504 to determine that a burst of one or more laser pulses (or a subset of one or more bursts) should be used for one or more calibration operations, the calibration filter 503 classifies the burst data block 504 (or a subset of the burst data block 504) into a calibration operation category and generates data 506c. In some embodiments, the data 506c may be sent to a metric generator 505. In these embodiments, the metric generator 505 may generate one or more metrics for the data 506c and store them, for example, in a table 507c. In some examples, the table 507c may be a database in a storage device. In some embodiments, the calibration filter 503 may send the burst data block 504 (or a subset of the burst data block 504) directly to a table (not shown, e.g., different from the table 507c) (e.g., bypassing the metric generator 505).

[0092]

[0104] As discussed above, in some embodiments, the calibration operation category may be further divided into two more subcategories, and the calibration filter 503 may be configured to analyze and aggregate the burst data blocks 504 (or a subset of the burst data blocks 504) into two or more subcategories. For example, each one of the two or more subcategories of the calibration operation category may be associated with one calibration operation. According to some embodiments, the calibration filter 503 may be configured to aggregate the burst data blocks 504 into subcategories associated with the corresponding calibration operation based on one or more parameters associated with the calibration operation. Using the one or more parameters associated with each calibration operation, the calibration filter 503 may aggregate the burst data blocks 504 into its associated calibration operation subcategory.

[0093]

[0105] According to some embodiments, to classify burst data block 504 into an on-wafer operation category and / or a calibration operation category, calibration filter 503 may begin by examining the number of bursts of laser pulses associated with burst data block 504. In this example, if calibration filter 503 determines that burst data block 504 is associated with one burst, calibration filter 503 may determine that the one burst is being used for a calibration operation. Thus, calibration filter 503 may classify (e.g., cluster) the one burst into a calibration operation category.

[0094]

[0106] On the other hand, if the calibration filter 503 determines that the burst data block 504 includes multiple bursts (a burst of two or more laser pulses), the calibration filter 503 may perform a calibration category test. The exemplary calibration category tests discussed below are discussed for one calibration operation (e.g., a sine wave calibration operation). However, the embodiments of this disclosure are not limited to this exemplary calibration category test. Other calibration category tests may be used for various calibration operations. In other words, the calibration filter 503 may perform one or more calibration category tests for one or more calibration operations. In some examples, each one of the calibration category tests may be designed based on one or more parameters specific to the calibration operation.

[0095]

[0107] According to some embodiments, to perform the calibration category test, the calibration filter 503 may consider three parameters associated with each burst in the burst data block 504. These parameters may include the number of pulses per burst (PPB), the high voltage command variation (HVV), and the inter-burst interval (IBI), although in other embodiments, the calibration filter 503 may consider fewer or more parameters or different parameters for the calibration category test.

[0096]

[0108] For each burst, the burst data block 504 may include the number of pulses in a burst (PPB). The calibration filter 503 is configured to determine the number of PPB for each burst in the burst data block 504. In some embodiments, the laser source 401 uses a high voltage command to generate each laser pulse in a burst. The HVV of a burst is the variation between the high voltage commands for the laser pulses in that burst. Also, according to some embodiments, the IBI may be defined as the period between two bursts in the burst data block 504.

[0097]

[0109] According to some embodiments, the calibration category test can be divided into two sections based on the number of bursts in the burst data block 504. For example, a burst count threshold can be used to divide the calibration category test into two sections. If the number of bursts in the burst data block 504 is less than or equal to the burst count threshold, the calibration filter 503 performs the calibration category test using the number of PPBs and HVV associated with the last burst in the burst data block 504. If the number of bursts in the burst data block 504 is greater than the burst count threshold, the calibration filter 503 performs the calibration category test using the number of PPBs, HVV, and IBI associated with the last burst in the burst data block 504. Some exemplary embodiments for performing the method of the calibration category test are discussed below in connection with FIGS. 6, 7A, and 7B.

[0098]

[0110] FIG. 6 illustrates an exemplary method 600 for determining and classifying a burst of one or more laser pulses, according to some embodiments of the present disclosure. For convenience and without limitation, FIG. 6 may be described with respect to elements of FIGS. 1-5. Method 600 may represent operations of data collection and analysis system 403 for determining and classifying a burst of one or more laser pulses. Method 600 may be performed by data collection and analysis system 403, cluster controller 501 and calibration filter 503 of FIG. 4A, and / or computer system 800 of FIG. 8. However, it will be understood by those skilled in the art that method 600 is not limited to the specific embodiments shown in these figures, and other systems may be used to perform the method. It should be understood that not all operations are required, and that the operations may not be performed in the same order as shown in FIG. 6.

[0099]

[0111] At 602, data associated with a burst of one or more laser pulses is received. For example, cluster controller 501 receives burst data 502. Burst data 502 may be based on raw burst data associated with one or more bursts from laser source 401.

[0100]

[0112] At 604, an energy control mode (ECM) value associated with one or more bursts is determined from the received burst data, and the ECM value is compared to a first ECM value. According to some embodiments, the first ECM value may be associated with a burst used for internal use. For example, the first ECM value may be ECM1 421 of Figures 4B-4D.

[0101]

[0113] If the determined ECM value associated with the one or more bursts is equal to the first ECM value, method 600 proceeds to 606. At 606, the one or more bursts are determined and classified as internal use bursts. For example, cluster controller 501 may determine that one or more bursts associated with the received burst data are for internal use. According to some embodiments, the received burst data may be classified and stored, for example, in table 507a associated with internal use bursts. Additionally or alternatively, the received burst data may be sent to metric generator 505 for generating one or more metric criteria based on the burst data. In this example, the generated one or more metric criteria may be stored, for example, in table 507a, and / or used to monitor and / or control laser source 401.

[0102]

[0114] If the determined ECM value associated with the one or more bursts is different from the first ECM value, method 600 proceeds to 608. At 608, a number of bursts associated with the received burst data is determined from the burst data and compared to a value of 1. Additionally or alternatively, at 608, one or more bursts are determined and classified as external use bursts. For example, cluster controller 501 may determine that one or more bursts associated with the received burst data are for external use. According to some embodiments, the received burst data is sent to calibration filter 503 to further determine whether one or more bursts associated with the received burst data are for on-wafer operations and / or for one or more calibration operations.

[0103]

[0115] As described above, at 608, the number of bursts associated with the received burst data is determined from the burst data and compared to a value of 1. If the one or more bursts include one burst, method 600 proceeds to 610, where the one burst data associated with the received burst data is determined and classified as a calibration burst. For example, calibration filter 503 determines that the one burst is a calibration burst, classifies the burst data into a calibration operation category, and stores the burst data, for example, in table 507c. Additionally or alternatively, the received burst data can be sent to metric generator 505 to generate one or more metrics based on the burst data. In this embodiment, the generated one or more metrics can be stored, for example, in table 507c, and / or used to monitor / control laser source 401 and / or monitor / control the lithography apparatus using laser source 401.

[0104]

[0116] If the one or more bursts include multiple bursts (two or more bursts), method 600 proceeds to 612 where a calibration category test is performed on the received burst data. Application of the calibration category test is discussed further below with respect to Figures 7A and 7B.

[0105]

[0117] At 614, it is determined whether a calibration category test is satisfied. For example, the calibration filter 503 applies the calibration category test and classifies one or more bursts associated with the received burst data based on the result. If the calibration category test is not satisfied, the method 600 proceeds to 616 where the one or more bursts are determined and classified as on-wafer bursts. For example, the calibration filter 503 determines that the bursts are on-wafer bursts, classifies the burst data into an on-wafer operation category, and stores the burst data, for example, in table 507b. Additionally or alternatively, the received burst data can be sent to the metric generator 505 to generate one or more metrics based on the burst data. In this embodiment, the generated one or more metrics can be stored, for example, in table 507b, and / or used to monitor / control the laser source 401 and / or monitor / control the lithography apparatus using the laser source 401.

[0106]

[0118] If the calibration category test is satisfied, method 600 proceeds to 618. At 618, the last burst of the one or more bursts is determined and classified as a calibration burst. For example, calibration filter 503 determines that the last burst is a calibration burst, classifies the burst data associated with the last burst into a calibration operation category, and stores the burst data associated with the last burst, for example, in table 507c. Additionally or alternatively, the received burst data associated with the last burst can be sent to metric generator 505 to generate one or more metrics based on the burst data. In this example, the generated one or more metrics can be stored, for example, in table 507c, and / or used to monitor / control laser source 401 and / or monitor / control the lithographic apparatus using laser source 401.

[0107]

[0119] Also, at 618, the remainder of the burst (except for the last burst) is determined and classified as an on-wafer burst. For example, the calibration filter 503 determines that the remainder of the burst is an on-wafer burst, classifies the burst data associated with the remainder of the burst into an on-wafer operation category, and stores the burst data associated with the remainder of the burst, for example in table 507b. Additionally or alternatively, the received burst data associated with the remainder of the burst can be sent to the metric generator 505 for generating one or more metrics based on the burst data. In this example, the generated one or more metrics can be stored, for example in table 507b, and / or used to monitor / control the laser source 401 and / or to monitor / control the lithography apparatus using the laser source 401.

[0108]

[0120] 7A and 7B illustrate an exemplary method 700 for determining and classifying one or more bursts as on-wafer or calibration bursts according to some embodiments of the present disclosure. For convenience and without limitation, FIGS. 7A and 7B may be described with respect to elements of FIGS. 1 through 6. Method 700 may represent operations of data collection and analysis system 403 for determining and classifying one or more bursts as on-wafer or calibration bursts. Method 700 may be performed by data collection and analysis system 403 of FIG. 4A, calibration filter 503, and / or computer system 800 of FIG. 8. However, it will be understood by those skilled in the art that method 700 is not limited to the specific embodiments shown in these figures and that other systems may be used to perform the method. It should be understood that not all operations are required and that the operations may not be performed in the same order as shown in FIGS. 7A and 7B.

[0109]

[0121] According to some embodiments, method 700 may be part of (or include) steps 612, 614, 616, and 618 of method 600 of Figure 6. In other words, application of the calibration category tests and analysis of the results of the calibration category tests may be performed by method 700 according to some embodiments.

[0110]

[0122] At 702, a number of bursts associated with the received burst data is determined from the burst data and compared to a burst count threshold. If the number of bursts associated with the burst data is less than or equal to the burst count threshold (e.g., not enough bursts are available), method 700 proceeds to 704. At 704, two thresholds are used to determine and classify the bursts. For example, at 704, a number of pulses per burst (PPB) of a last burst of one or more bursts associated with the burst data may be determined (e.g., from the received burst data). The number of PPBs of the last burst may be compared to a PPB threshold. Additionally or alternatively, a high voltage command variation (HVV) of a last burst of one or more bursts associated with the burst data may be determined (e.g., from the received burst data). The HVV of the last burst may be compared to an HVV threshold.

[0111]

[0123] If the number of PPBs associated with the last burst is greater than the PPB threshold or the HVV associated with the last burst is greater than the HVV threshold, then the calibration category test is determined to be satisfied (Yes to 614 of FIG. 6). In this embodiment, method 700 proceeds to 708, which is similar to 618 of FIG.

[0112]

[0124] Otherwise (e.g., if the number of PPBs associated with the last burst is less than or equal to the PPB threshold and the HVV associated with the last burst is less than or equal to the HVV threshold), it is determined that the calibration category test is not satisfied (No to 614 of FIG. 6). In this embodiment, method 700 proceeds to 706, which is similar to 616 of FIG. 6.

[0113]

[0125] Returning to 702, if the number of bursts associated with the burst data is greater than the burst count threshold (e.g., sufficient bursts are available), method 700 proceeds to 710, shown in FIG. 7B. At 710, data from the burst data associated with the first and last bursts is removed from the burst data. For example, calibration filter 503 removes data from the burst data associated with the first and last bursts to generate first modified burst data.

[0114]

[0126] At 712, data associated with the burst having the largest inter-burst interval is removed from the first modified burst data. For example, calibration filter 503 removes data associated with the burst having the largest inter-burst interval (IBI) to generate the second modified burst data. To do so, calibration filter 503 can determine and analyze the IBI of each burst from the first modified burst data, according to some embodiments. Using this analysis, calibration filter 503 can determine the burst with the largest IBI.

[0115]

[0127] At 714, the IBI values ​​in the second modified burst data are used to calculate an average IBI value. Additionally or alternatively, a standard deviation value of the IBI is calculated based on the IBI values ​​in the second modified data. For example, the calibration filter 503 can calculate and generate the average IBI value and the standard deviation IBI value.

[0116]

[0128] At 716, an IBI threshold is determined based on the mean IBI value, the standard deviation IBI value, and the IBI parameters. The following equation represents one exemplary IBI threshold:

[0129] IBI threshold = mean IBI value + (C * standard deviation IBI value).

[0130] where C is an IBI parameter. In some embodiments, C may be a configurable parameter.

[0117]

[0131] In this example, the IBI threshold is determined based on the second correction data (based on the received burst data). In other words, the IBI threshold is determined dynamically and based on the received burst data. However, the embodiments of this disclosure are not limited to this example, and other formulas can be used to determine the IBI threshold. Alternatively, the IBI threshold can be a fixed threshold provided to the calibration filter 503.

[0118]

[0132] Three thresholds are used to determine and classify the bursts at 718. For example, at 718, an IBI associated with a last burst in the one or more bursts associated with the burst data may be determined (e.g., from the received burst data). The IBI of the last burst may be compared to the IBI threshold calculated at 716. Also, a number of pulses per burst (PPB) of a last burst in the one or more bursts associated with the burst data may be determined (e.g., from the received burst data). The number of PPBs of the last burst may be compared to a PPB threshold. Additionally or alternatively, a high voltage command variation (HVV) of a last burst of the one or more bursts associated with the burst data may be determined (e.g., from the received burst data). The HVV of the last burst may be compared to an HVV threshold.

[0119]

[0133] If the IBI associated with the last burst is greater than the IBI threshold and the number of PPBs associated with the last burst is greater than the PPB threshold or the HVV associated with the last burst is greater than the HVV threshold, then the calibration category test is determined to be satisfied (Yes to 614 of FIG. 6). In this embodiment, method 700 proceeds to 722, which is similar to 618 of FIG. 6.

[0120]

[0134] Otherwise (e.g., if the IBI associated with the last burst is less than or equal to the IBI threshold, or the number of PPBs associated with the last burst is less than or equal to the PPB threshold and the HVV associated with the last burst is less than or equal to the HVV threshold), it is determined that the calibration category test is not satisfied (No to 614 of FIG. 6). In this embodiment, method 700 proceeds to 720, which is similar to 616 of FIG. 6.

[0121]

[0135] Methods 600 and 700 are discussed above for using IBI, PPB, and HVV parameters to determine (and classify) whether a burst is a calibration burst. However, the methods and systems of this disclosure are not limited to these parameters. The embodiments of this disclosure may be applied to distinguishing an on-wafer burst from a calibration burst for one or more different calibration operations. For each calibration operation, one or more parameters (e.g., features) of the calibration burst that differentiate the calibration burst from an on-wafer burst may be used in distinguishing and classifying the burst.

[0122]

[0136] For example, the one or more bursts of laser pulses may include a first calibration burst used for a first calibration operation, a second calibration burst used for a second calibration operation, and one or more on-wafer bursts used for on-wafer operations. In this example, the first calibration burst may include a first feature that differentiates the first calibration burst from an on-wafer burst. Also, the second calibration burst may include a second feature that differentiates the second calibration burst from an on-wafer burst. In this example, the data acquisition and analysis system 403 may use the first feature of the first calibration burst and the second feature of the second calibration burst to distinguish the first and second calibration bursts from the on-wafer bursts. Additionally or alternatively, the data acquisition and analysis system 403 may use the first feature of the first calibration burst and the second feature of the second calibration burst to distinguish the first and second calibration bursts from each other.

[0123]

[0137] According to some embodiments, a calibration burst can be paired with its corresponding wafer when the calibration burst is identified, for example, by data collection and analysis system 403. In some examples, this pairing can be performed by data collection and analysis system 403. For example, the pairing can be performed by calibration filter 503, and the pairing can be stored, for example, in table 507c.

[0124]

[0138] According to some embodiments, for each calibration burst identified, e.g., by the data collection and analysis system 403, the wafer identifier (ID) of the subsequent wafer (in time) is assigned to the identified calibration burst (e.g., by the data collection and analysis system 403). If two or more consecutive calibration bursts are identified that do not include a wafer (a group of bursts associated with a wafer) in between, the last calibration burst is assigned the wafer ID. In this embodiment, the (one or more) previous calibration bursts are stored with an empty wafer ID. In some embodiments, if the time between the identification of a calibration burst and the use of the subsequent wafer is greater than a threshold, a wafer ID is not assigned to the identified calibration burst.

[0125]

[0139] The embodiments of the present disclosure may be implemented in hardware, firmware, software, or any combination thereof. The embodiments of the present disclosure may also be implemented as instructions stored on a machine-readable medium that may be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, a machine-readable medium may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium, an optical storage medium, a flash memory device, an electrical, optical, acoustic, or other form of propagated signal, and the like. Furthermore, firmware, software, routines, and / or instructions may be described herein as performing certain actions. However, it should be understood that such description is merely for convenience and that such actions are actually caused by a computing device, processor, controller, or other device executing the firmware, software, routines, and / or instructions.

[0126]

[0140] Various embodiments can be implemented using one or more computer systems, such as computer system 800 shown in FIG. 8. Computer system 800 can be any known computer capable of performing the functions described herein, such as the functions performed by data collection and analysis system 403 of FIG. 4A, cluster controller 501 of FIG. 5, calibration filter 503 of FIG. 5, and / or metric generator 505 of FIG. 5. Computer system 800 includes one or more processors (also referred to as central processing units, or CPUs), such as processor 804. Processor 804 is connected to a communications infrastructure 806 (e.g., a bus). Computer system 800 also includes user input / output devices 803, such as a monitor, keyboard, pointing device, etc., that communicate with communications infrastructure 806 via user input / output interface 802. Computer system 800 also includes a main or primary memory 808, such as a random access memory (RAM). Main memory 808 may include one or more levels of cache. Main memory 808 stores control logic (e.g., computer software) and / or data internally.

[0127]

[0141] Computer system 800 may also include one or more secondary storage devices or memories 810. The secondary memory 810 may include, for example, a hard disk drive 812 and / or a removable storage device or drive 814. The removable storage drive 814 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.

[0128]

[0142] The removable storage drive 814 may interact with a removable storage unit 818. The removable storage unit 818 includes a computer usable or readable storage device that stores computer software (control logic) and / or data. The removable storage unit 818 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 814 reads from and / or writes to the removable storage unit 818 in a well-known manner.

[0129]

[0143] According to some embodiments, secondary memory 810 may include other techniques, means, or other manners by which computer programs and / or other instructions and / or data may be accessed by computer system 800. Such techniques, means, or other manners may include, for example, a removable storage unit 822 and interface 820. Examples of removable storage unit 822 and interface 820 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 a USB port, a memory card and associated memory card slot, and / or any other removable storage unit and associated interface.

[0130]

[0144] Computer system 800 may further include a communications or network interface 824. Communications interface 824 enables computer system 800 to communicate and interact with any combination of remote devices, remote networks, remote entities, etc. (individually and collectively as indicated by reference numeral 828). For example, communications interface 824 may enable computer system 800 to communicate with remote devices 828 over communications path 826, which may be wired and / or wireless and may include any combination of a LAN, a WAN, the Internet, etc. Control logic and / or data may be transferred to and from computer system 800 over communications path 826.

[0131]

[0145] The operations in the aforementioned embodiments can be implemented in a wide variety of configurations and architectures. Thus, some or all of the operations in the aforementioned embodiments may be performed in hardware, software, or both. In some embodiments, a tangible, non-transitory apparatus or article of manufacture includes a tangible, non-transitory, computer usable or readable medium having stored thereon control logic (software), also referred to herein as a computer program product or program storage device. This includes, but is not limited to, tangible articles of manufacture embodying computer system 800, main memory 808, secondary memory 810, and removable storage units 818 and 822, and any combination thereof. Such control logic, when executed by one or more data processing devices (such as computer system 800), causes such data processing devices to operate as described herein.

[0132]

[0146] Based on the teachings contained herein, it will be apparent to one of ordinary skill in the art how to make and use embodiments of the present disclosure using data processing devices, computer systems, and / or computer architectures other than those shown in Figure 8. In particular, embodiments may operate in conjunction with software, hardware, and / or operating system implementations other than those described herein.

[0133]

[0147] Although particular reference is made herein to the use of lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein has 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, and the like. In light of these alternative applications, those skilled in the art will recognize that the use of the terms "wafer" or "die" herein may be considered synonymous with the more general terms "substrate" or "target portion", respectively. The substrates described herein may be processed, before or after exposure, for example in a track (a tool that typically applies a layer of resist to the substrate and develops the exposed resist), a metrology unit, and / or an inspection unit. Where appropriate, the disclosure herein may be applied to these and other substrate processing tools. Furthermore, the substrate may be processed multiple times, for example to produce a multi-layer IC, and thus the term substrate as used herein may also refer to a substrate that already includes multiple processed layers.

[0134]

[0148] It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, and thus, the terminology or terminology herein should be interpreted by one of skill in the art in light of the teachings herein.

[0135]

[0149] The term "substrate" as used herein describes a material onto which a layer of material is added. In some embodiments, the substrate itself may be patterned, and the material added onto it may also be patterned or may remain unpatterned.

[0136]

[0150] The following examples are illustrative of embodiments of the disclosure without, however, limiting them. Other suitable modifications and adaptations of the variety of conditions and parameters normally encountered in the art and obvious to those skilled in the art are within the spirit and scope of the disclosure.

[0137]

[0151] Although specific reference may be made in this text to the use of the apparatus and / or system according to the invention in the manufacture of ICs, it should be explicitly understood that such an apparatus and / or system has many other possible applications, such as in integrated optical systems, guidance and detection patterns for magnetic domain memories, LCD panels, thin film magnetic heads, etc. In light of these alternative applications, those skilled in the art will recognize that where the terms "reticle," "wafer," or "die" are used herein, they may be considered interchangeable with the more general terms "mask," "substrate," and "target portion," respectively.

[0138]

[0152] While specific embodiments of the present disclosure have been described above, it will be understood that the embodiments may be practiced otherwise than as described, and the present disclosure is not intended to limit the embodiments.

[0139]

[0153] It is understood that the Detailed Description section is intended to be used to interpret the claims, rather than the Summary and Abstract sections. The Summary and Abstract sections may describe one or more exemplary embodiments as envisioned by the inventors, but cannot describe all exemplary embodiments, and thus are not intended to limit the scope of the present embodiments and the appended claims in any way.

[0140]

[0154] In the above, an embodiment has been described using functional components and their relationships that illustrate examples of specific functions. The boundaries of these functional components are arbitrarily defined in this specification for the convenience of description. Alternative boundaries can be defined as long as the specific functions and their relationships are appropriately performed.

[0141]

[0155] The foregoing description of the specific embodiments fully discloses the general nature of the embodiments, such that those skilled in the art can, without undue experimentation, readily modify and / or adapt such specific embodiments to various applications without departing from the general concept of the present disclosure. Accordingly, 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.

[0142]

[0156] Other aspects of the invention are set forth in the following numbered clauses. 1. A laser source that generates a burst of one or more laser pulses; A laser analysis system comprising: The data collection and analysis system receiving data from a laser source relating to a burst of one or more laser pulses; determining, based on the received data, that the burst of one or more laser pulses is for external use; A laser analysis system that determines whether the burst of one or more laser pulses is for an on-wafer operation or a calibration operation based on the received data. 2. A data acquisition and analysis system for determining that a burst of one or more laser pulses is for external use. determining from the received data an energy control mode (ECM) value associated with a burst of one or more laser pulses; Comparing the determined ECM value to the first ECM value; The laser analysis system of clause 1, determining that the burst of one or more laser pulses is for external use in response to the determined ECM value differing from the first ECM value. 3. The data collection and analysis system further Determining the number of bursts within the one or more bursts of laser pulses; 2. The laser analysis system of claim 1, in response to determining that the burst of one or more laser pulses includes a burst, determining that the burst of one laser pulse is for a calibration operation. 4. The data collection and analysis system further 4. The laser analysis system of clause 3, in response to determining that the burst of one or more laser pulses comprises a plurality of bursts, applies a calibration category test to the received data. 5. The data collection and analysis system further In response to a calibration category test being satisfied, determining that a last burst of the one or more bursts is for a calibration operation; The laser analysis system of clause 4, determining that other of the one or more bursts are for on-wafer operation. 6. The data collection and analysis system further 5. The laser analysis system of claim 4, in response to a calibration category test not being satisfied, determining that one or more bursts are for on-wafer operation. 7. The data collection and analysis system further: generating first correction data by excluding data associated with a first burst and a last burst of the one or more bursts from the received data; generating second corrected data by excluding data associated with a burst having a maximum inter-burst interval (IBI) value from the first corrected data; generating an average IBI value based on the IBI values ​​in the second corrected data; generating a standard deviation value based on the IBI values ​​in the second corrected data; Clause 4. The laser analysis system of clause 4, generating an IBI threshold value based on the mean IBI value, the standard deviation value, and the IBI parameters. 8. The data collection and analysis system further: determining that a calibration category test is satisfied in response to an IBI value associated with the last burst being greater than an IBI threshold and a pulses per burst (PPB) associated with the last burst being greater than a PBB threshold or a high voltage command variation (HVV) associated with the last burst being greater than an HVV threshold; In response to determining that the calibration category tests are satisfied, determining that a last burst of the one or more bursts is for a calibration operation; The laser analysis system of clause 7, determining that other of the one or more bursts are for on-wafer operation. 9. The data collection and analysis system further: determining that a first portion of the one or more bursts is for a calibration operation; determining that a second portion of the one or more bursts is for on-wafer operation; and determining, from the received data, one or more metrics of the second portion of the one or more bursts using data relating to the second portion of the one or more bursts. 10. The one or more bursts include a calibration burst used for a calibration operation and one or more on-wafer bursts used for an on-wafer operation; the calibration burst includes a feature that differentiates the calibration burst from one or more on-wafer bursts; 2. The laser analysis system of claim 1, wherein the data collection and analysis system uses a characteristic of the calibration burst to distinguish the calibration burst from one or more on-wafer bursts. 11. The laser analysis system of clause 10, wherein the data collection and analysis system further assigns a wafer identifier to the calibration burst. 12. The one or more bursts include a first calibration burst used for a calibration operation, a second calibration burst used for a second calibration operation, and one or more on-wafer bursts used for an on-wafer operation; the first calibration burst includes a first feature that differentiates the first calibration burst from the one or more on-wafer bursts; the second calibration burst includes a second feature that differentiates the second calibration burst from the one or more on-wafer bursts; 2. The laser analysis system of claim 1, wherein the data collection and analysis system distinguishes the first and second calibration bursts from the one or more on-wafer bursts using a first characteristic of the first calibration burst and a second characteristic of the second calibration burst. 13. A method of analyzing data relating to a laser source, comprising: receiving, from the laser source at a data acquisition and analysis system, data relating to a burst of one or more laser pulses generated by the laser source; determining, based on the data received by the data acquisition and analysis system, that the burst of one or more laser pulses is for external use; and The method includes determining whether the burst of one or more laser pulses is for an on-wafer operation or a calibration operation based on data received by a data collection and analysis system. 14. The data collection and analysis system determining that a first portion of the one or more bursts is for a calibration operation; the data collection and analysis system determining that a second portion of the one or more bursts is for on-wafer operation; and 14. The method of clause 13, further comprising the data collection and analysis system determining one or more metrics of the second portion of the one or more bursts using data associated with the second portion of the one or more bursts. 15. The one or more bursts include a calibration burst used for a calibration operation and one or more on-wafer bursts used for an on-wafer operation; the calibration burst includes a feature that differentiates the calibration burst from one or more on-wafer bursts; 14. The method of clause 13, wherein the method further includes distinguishing the calibration burst from one or more on-wafer bursts using a characteristic of the calibration burst. 16. The one or more bursts include a first calibration burst used for a calibration operation, a second calibration burst used for a second calibration operation, and one or more on-wafer bursts used for an on-wafer operation; the first calibration burst includes a first feature that differentiates the first calibration burst from the one or more on-wafer bursts; the second calibration burst includes a second feature that differentiates the second calibration burst from the one or more on-wafer bursts; 14. The method of clause 13, further comprising distinguishing the first and second calibration bursts from the one or more on-wafer bursts using a first characteristic of the first calibration burst and a second characteristic of the second calibration burst. 17. Determining that one or more bursts of laser pulses are for external use is determining, from the received data, an energy control mode (ECM) value associated with a burst of one or more laser pulses; comparing the determined ECM value to the first ECM value; and 14. The method of clause 13, comprising determining, in response to the determined ECM value being different from the first ECM value, that the burst of one or more laser pulses is for external use. 18. Determining the number of bursts within a burst of one or more laser pulses; In response to determining that the burst of one or more laser pulses includes a burst, determining that the burst of one laser pulse is for a calibration operation; and 14. The method of clause 13, further comprising, in response to determining that the burst of one or more laser pulses comprises a plurality of bursts, applying a calibration category test to the received data. 19. In response to a calibration category test being met, determining that a last burst of the one or more bursts is for a calibration operation; and determining that other of the one or more bursts are for on-wafer operation; and The method of clause 13, further comprising determining, in response to a calibration category test not being satisfied, that the one or more bursts are for on-wafer operation. 20. generating first modified data by excluding data associated with a first burst and a last burst of the one or more bursts from the received data; excluding data associated with a burst having a maximum inter-burst interval (IBI) value from the first corrected data to generate second corrected data; generating an average IBI value based on the IBI values ​​in the second corrected data; generating a standard deviation value based on the IBI values ​​in the second corrected data; generating an IBI threshold based on the mean IBI value, the standard deviation value, and the IBI parameter; and 20. The method of clause 19, further comprising determining that a calibration category test is satisfied in response to an IBI value associated with the last burst being greater than an IBI threshold and a pulses per burst (PPB) associated with the last burst being greater than a PBB threshold or a high voltage command variation (HVV) associated with the last burst being greater than an HVV threshold. 21. An illumination system for adjusting a radiation beam; a projection system configured to project a pattern imparted to the radiation beam onto a substrate, the projection system comprising: The lighting system is a laser source generating one or more bursts of laser pulses; a data collection and analysis system; The data collection and analysis system receiving data from a laser source relating to a burst of one or more laser pulses; determining, based on the received data, that the burst of one or more laser pulses is for external use; The lithography apparatus determines whether the burst of one or more laser pulses is for an on-wafer operation or a calibration operation based on the received data. 22. Receiving data from a laser source relating to a burst of one or more laser pulses generated by the laser source; determining, based on the received data, that the burst of one or more laser pulses is for external use; and A non-transitory computer-readable medium storing instructions that, when executed by the processor, cause a processor to perform operations including determining whether a burst of one or more laser pulses is for an on-wafer operation or a calibration operation based on the received data.

[0143]

[0156] The breadth and scope of the present embodiments 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 laser source generating a burst of one or more laser pulses; A laser analysis system comprising: The data collection and analysis system comprises: receiving data from the laser source relating to the burst of one or more laser pulses; determining whether the burst of one or more laser pulses is for an internal use of the laser source or an external use of the laser source based on the received data; and a laser analysis system that, when the burst of one or more laser pulses is determined to be for the external use, determines whether the burst of one or more laser pulses is for an on-wafer operation or a calibration operation based on the received data.

2. to determine that the burst of one or more laser pulses is for the external use, the data acquisition and analysis system comprising: determining an energy control mode (ECM) value associated with the burst of one or more laser pulses from the received data; comparing the determined ECM value to a first ECM value; The laser analysis system of claim 1 , responsive to the determined ECM value differing from the first ECM value, determining that the burst of one or more laser pulses is for the external use.

3. The data collection and analysis system further comprises: determining a number of bursts within the burst of one or more laser pulses; 2. The laser analysis system of claim 1, responsive to determining that the one or more bursts of laser pulses includes a single burst, determining that the single burst of laser pulses is for the calibration operation.

4. The data collection and analysis system further comprises: The laser analysis system of claim 3 , responsive to determining that the burst of one or more laser pulses comprises a plurality of bursts, applying a calibration category test to the received data.

5. The data collection and analysis system further comprises: in response to the calibration category test being satisfied, determining that a last burst of the one or more bursts is for the calibration operation; The laser analysis system of claim 4 , further comprising: determining that other of said one or more bursts are for said on-wafer operation.

6. The data collection and analysis system further comprises:

5. The laser analysis system of claim 4, responsive to said calibration category test not being satisfied, determining that said one or more bursts are for said on-wafer operation.

7. The data collection and analysis system further comprises: generating first correction data by excluding data associated with a first burst and a last burst of the one or more bursts from the received data; generating second correction data by excluding from the first correction data data associated with a burst having a maximum inter-burst interval (IBI) value; generating an average IBI value based on the IBI values ​​in the second correction data; generating a standard deviation value based on the IBI values ​​in the second corrected data; The laser analysis system of claim 4 , further comprising: generating an IBI threshold based on the mean IBI value, the standard deviation value, and an IBI parameter.

8. The data collection and analysis system further comprises: determining that the calibration category test is satisfied in response to an IBI value associated with the last burst being greater than the IBI threshold and a number of pulses per burst (PPB) associated with the last burst being greater than a PPB threshold or a high voltage command variation (HVV) associated with the last burst being greater than a HVV threshold; in response to determining that the calibration category test is satisfied, determining that the last burst of the one or more bursts is for the calibration operation; The laser analysis system of claim 7 , further comprising: determining that other of said one or more bursts are for said on-wafer operation.

9. The data collection and analysis system further comprises: determining that a first portion of the one or more bursts is for the calibration operation; determining that a second portion of the one or more bursts is for the on-wafer operation; 2. The laser analysis system of claim 1 , further comprising: a first input for receiving said one or more bursts from said one or more bursts; a second input for receiving said one or more bursts from said one or more bursts;

10. the one or more bursts include a calibration burst used for the calibration operation and one or more on-wafer bursts used for the on-wafer operation; the calibration burst includes a feature that differentiates the calibration burst from the one or more on-wafer bursts; The laser analysis system of claim 1 , wherein the data collection and analysis system uses the characteristics of the calibration burst to distinguish the calibration burst from the one or more on-wafer bursts.

11. The laser analysis system of claim 10 , wherein the data collection and analysis system further assigns a wafer identifier to the calibration burst.

12. the one or more bursts include a first calibration burst used for the calibration operation, a second calibration burst used for a second calibration operation, and one or more on-wafer bursts used for the on-wafer operation; the first calibration burst includes a first feature that differentiates the first calibration burst from the one or more on-wafer bursts; the second calibration burst includes a second characteristic that differentiates the second calibration burst from the one or more on-wafer bursts; 2. The laser analysis system of claim 1, wherein the data collection and analysis system uses the first feature of the first calibration burst and the second feature of the second calibration burst to distinguish the first and second calibration bursts from the one or more on-wafer bursts.

13. 1. A method for analyzing data relating to a laser source, comprising: receiving, from a laser source at a data collection and analysis system, data relating to a burst of one or more laser pulses generated by said laser source; determining, based on the received data, whether the burst of one or more laser pulses is for an internal use of the laser source or an external use of the laser source; and When the burst of one or more laser pulses is determined to be for the external use, the data collection and analysis system determines based on the received data whether the burst of one or more laser pulses is for an on-wafer operation or a calibration operation.

14. the data collection and analysis system determining that a first portion of the one or more bursts is for the calibration operation; the data collection and analysis system determining that a second portion of the one or more bursts is for the on-wafer operation; and 14. The method of claim 13, further comprising the data collection and analysis system using data associated with the second portion of the one or more bursts to determine one or more metrics of the second portion of the one or more bursts.

15. the one or more bursts include a calibration burst used for the calibration operation and one or more on-wafer bursts used for the on-wafer operation; the calibration burst includes a feature that differentiates the calibration burst from the one or more on-wafer bursts; 14. The method of claim 13, further comprising: using the characteristics of the calibration burst to distinguish the calibration burst from the one or more on-wafer bursts.

16. the one or more bursts include a first calibration burst used for the calibration operation, a second calibration burst used for a second calibration operation, and one or more on-wafer bursts used for the on-wafer operation; the first calibration burst includes a first feature that differentiates the first calibration burst from the one or more on-wafer bursts; the second calibration burst includes a second characteristic that differentiates the second calibration burst from the one or more on-wafer bursts; 14. The method of claim 13, further comprising distinguishing the first and second calibration bursts from the one or more on-wafer bursts using the first feature of the first calibration burst and the second feature of the second calibration burst.

17. determining that the burst of one or more laser pulses is for the external use; determining from the received data an energy control mode (ECM) value associated with the burst of one or more laser pulses; comparing the determined ECM value to a first ECM value; and 14. The method of claim 13, comprising determining that the burst of one or more laser pulses is for the external use in response to the determined ECM value being different from the first ECM value.

18. determining a number of bursts within the burst of one or more laser pulses; in response to determining that the one or more bursts of laser pulses include a burst, determining that the burst of one laser pulse is for the calibration operation; and The method of claim 13 , further comprising, in response to determining that the burst of one or more laser pulses comprises a plurality of bursts, applying a calibration category test to the received data.

19. in response to the calibration category test being satisfied, determining that a last burst of the one or more bursts is for the calibration operation; and determining that other of the one or more bursts are for the on-wafer operation; and 14. The method of claim 13, further comprising: in response to the calibration category test not being satisfied, determining that the one or more bursts are for the on-wafer operation.

20. generating first modified data by excluding data associated with a first burst and a last burst of the one or more bursts from the received data; excluding data associated with a burst having a maximum inter-burst interval (IBI) value from the first correction data to generate second correction data; generating an average IBI value based on the IBI values ​​in the second correction data; generating a standard deviation value based on the IBI values ​​in the second correction data; generating an IBI threshold based on the mean IBI value, the standard deviation value, and an IBI parameter; and 20. The method of claim 19, further comprising: determining that the calibration category test is satisfied in response to an IBI value associated with the last burst being greater than the IBI threshold and a number of pulses per burst (PPB) associated with the last burst being greater than a PPB threshold or a high voltage command variation (HVV) associated with the last burst being greater than an HVV threshold.

21. an illumination system for conditioning a beam of radiation; a projection system configured to project a pattern imparted to the radiation beam onto a substrate, the projection system comprising: The lighting system comprises: a laser source generating a burst of one or more laser pulses; a data collection and analysis system; The data collection and analysis system comprises: receiving data from the laser source relating to the burst of one or more laser pulses; determining whether the burst of one or more laser pulses is for an internal use of the laser source or an external use of the laser source based on the received data; A lithographic apparatus that, when it is determined that the burst of one or more laser pulses is for the external use, determines whether the burst of one or more laser pulses is for an on-wafer operation or a calibration operation based on the received data.

22. receiving data from a laser source relating to a burst of one or more laser pulses generated by said laser source; determining, based on the received data, whether the burst of one or more laser pulses is for an internal use of the laser source or an external use of the laser source; and A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause a processor to perform operations including determining, when the burst of one or more laser pulses is determined to be for the external use, whether the burst of one or more laser pulses is for an on-wafer operation or a calibration operation based on the received data.

Images