A method of controlling manufacturing apparatus and related apparatus

Abstract

A method for determining a correction to control of at least one manufacturing device used in a manufacturing process for providing a structure for at least one region on a substrate, the region comprising at least a first sub-region and a second sub-region in a common layer is disclosed. The method comprises: obtaining process error data relating to the manufacturing process when forming the first sub-region on the substrate; determining a first on-product error from the process error data, the on-product error relating to an error in the formation of the first sub-region; and determining a correction to the manufacturing process from the on-product error when forming the second sub-region on the substrate.

Description

Cross-reference to related applications

[0001] This application claims priority to European Patent Application No. 24150622.9, filed on January 8, 2024, and European Patent Application No. 24166061.2, filed on March 25, 2024, which are incorporated herein by reference in their entirety. Technical Field

[0002] The present invention relates to a method and apparatus for applying a pattern to a substrate in a photolithography process. Background Technology

[0003] A photolithography apparatus is a machine that applies a desired pattern onto a substrate (typically a target portion of the substrate). For example, photolithography apparatuses are used in the fabrication of integrated circuits (ICs). In this instance, a patterning apparatus (also known as a mask or photomask) can be used to generate a circuit pattern formed on a single layer of the IC. This pattern can then be transferred onto a target portion (e.g., a portion containing one or more dies) on a substrate (e.g., a silicon wafer). Pattern transfer is typically achieved by imaging onto a layer of radiation-sensitive material (resist) disposed on the substrate. Generally, a single substrate comprises a network of continuously patterned adjacent target portions. Known photolithography apparatuses include: so-called steppers, in which each target portion is irradiated by exposing the entire pattern to the target portion at once; and so-called scanners, in which each target portion is irradiated by scanning the pattern in a given direction (“scan”-direction) with a radiation beam, while simultaneously scanning the target portion parallel or antiparallel to this scan direction. Patterns can also be transferred from a patterning apparatus to a substrate by imprinting the pattern onto the substrate.

[0004] To monitor the photolithography process, parameters of the patterned substrate are measured. These parameters may include, for example, overlay errors between successive layers formed in or on the patterned substrate, and the critical linewidth (CD) of the developed photoresist. This measurement can be performed on the product substrate and / or a dedicated measurement target. Various techniques exist for measuring the microstructures formed in the photolithography process, including scanning electron microscopy and the use of various specialized tools. One rapid and non-destructive form of specialized detection tool is a scatterometer, in which a radiation beam is directed onto a target on the substrate surface, and the characteristics of the scattered or reflected beam are measured. Two main types of scatterometers are known: spectral scatterometers direct a broadband radiation beam onto the substrate and measure the spectrum (intensity as a function of wavelength) of the radiation scattered over a specific narrow angular range. Angle-resolved scatterometers use a monochromatic radiation beam and measure the intensity of the scattered radiation as a function of angle.

[0005] Examples of known scatterers include angle-resolved scatterers of the type described in US2006033921A1 and US2010201963A1. Such scatterers use relatively large (e.g., 40 μm × 40 μm) gratings as targets, and the measurement beam generates a spot smaller than the grating (i.e., the grating is underfilled). In addition to reconstructing the shape of the measurement feature, diffraction-based overlay measurements can also be performed using such devices, as described in published patent application US2006066855A1. Diffraction-based overlay measurements using dark-field imaging of diffraction orders enable overlay measurements of even smaller targets. Examples of dark-field imaging measurements can be found in international patent applications WO2009 / 078708 and WO2009 / 106279, which are incorporated herein by reference in their entirety. Further developments in the technology have been described in published patent documents US20110027704A, US20110043791A, US2011102753A1, US20120044470A, US20120123581A, US20130258310A, US20130271740A, and WO2013178422A1. These targets can be smaller than the illumination spot and can be surrounded by the product structure on the wafer. Using composite grating targets, multiple gratings can be measured in a single image. The contents of all these applications are also incorporated herein by reference.

[0006] When performing photolithography processes (such as patterning on a substrate or measuring such patterns), process control methods are used to monitor and control the process. These process control techniques are typically performed to obtain corrections for controlling the photolithography process. Improving these process control methods is desirable.

[0007] In particular, sometimes it is necessary to "stitch" a die together from two or more sub-regions, for example, where each sub-region corresponds to an exposure field of a specific lithography apparatus, and the die size is larger than the field size. Improvements in the process control methods used for stitching dies for exposure would be desirable. Summary of the Invention

[0008] In a first aspect of the invention, a method for determining corrections is provided for controlling at least one manufacturing apparatus used in a manufacturing process for providing a structure for at least one region on a substrate, the region including at least a first sub-region and a second sub-region in a common layer; the method includes: acquiring process error data related to the manufacturing process when forming the first sub-region on the substrate; determining a first on-product error based on the process error data, the on-product error being related to an error in the formation of the first sub-region; and determining corrections to the manufacturing process based on the on-product error when forming the second sub-region on the substrate.

[0009] In a second aspect of the invention, a method for determining corrections is provided for controlling at least one manufacturing apparatus used in a manufacturing process for providing a structure for at least one region on a substrate, the region comprising at least a first sub-region and a second sub-region in a common layer, wherein the first sub-region and the second sub-region comprise a common splicing region defined by an overlap region of the first sub-region and the second sub-region; the method comprising: acquiring process error data related to the manufacturing process while forming the first sub-region and the second sub-region on the substrate; and determining a co-optimized correction for each of the at least first sub-region and the second sub-region based on the process error data, wherein determining the co-optimized correction comprises applying at least one of the following: splicing region performance penalties and / or constraints, which impose penalties and / or constraints on at least one parameter of concern within the splicing region; and / or through-stack penalties and / or constraints, which impose penalties and / or constraints on overlay errors relative to at least one subsequent layer exposed after the common layer.

[0010] A third aspect of the invention provides a process apparatus for determining corrections to the control of at least one manufacturing apparatus configured to provide a product structure for a substrate in a manufacturing process, the process apparatus being configured to perform the method of the first or second aspect.

[0011] In a fourth aspect of the invention, a computer program is provided, including program instructions that, when run on a suitable device, are operable to perform the methods of the first or second aspect.

[0012] In a fifth aspect of the invention, a manufacturing apparatus is provided, configured to provide a product structure for a substrate in a manufacturing process, the manufacturing apparatus comprising the process apparatus of the third aspect.

[0013] Further aspects, features, and advantages of the invention, as well as the structure and operation of various embodiments of the invention, are described in detail below in conjunction with the accompanying drawings. It should be noted that the invention is not limited to the specific embodiments described herein. These embodiments presented herein are for illustrative purposes only. Additional embodiments will be apparent to those skilled in the art based on the teachings contained herein. Attached Figure Description

[0014] Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0015] Figure 1 This illustrates how photolithography equipment, along with other equipment, forms a semiconductor device manufacturing facility.

[0016] Figure 2A schematic diagram of a scatterer for measuring a target according to an embodiment of the present invention is included;

[0017] Figure 3 The arrangement of the splicing tube cores is explained, and the splicing target is shown in detail;

[0018] Figure 4 This describes the multi-channel, multi-exposure sequence used for exposing and splicing the core;

[0019] Figure 5 This is a flowchart of a method for determining splicing correction of sub-regions for splicing cores according to an embodiment;

[0020] Figure 6 The illustration demonstrates the use of two masks in a stitched exposure, illustrating how to increase the depth of focus within the stitched area of ​​the stitched exposure.

[0021] Figure 7 The illustration demonstrates the use of two masks in a stitched exposure, illustrating the method of allocating corrections between the two exposures within the stitched area of ​​the stitched exposure; and

[0022] Figure 8 The illustration demonstrates the use of two masks for stitched exposure, illustrating a method for measuring stitched overlay without the need for a dedicated target. Detailed Implementation

[0023] Before describing the embodiments of the present invention in detail, it is illustrative to present exemplary environments in which the embodiments of the present invention can be implemented.

[0024] Figure 1 A lithography apparatus LA is shown at position 200, which is part of an industrial production facility that implements high-volume lithography manufacturing processes. In this example, the manufacturing process is adapted to manufacture semiconductor products (integrated circuits) on substrates such as semiconductor wafers. Those skilled in the art will understand that various types of products can be manufactured by processing different types of substrates with different variations of this process. The production of semiconductor products is used purely as an example of significant commercial importance today.

[0025] Within the lithography apparatus (or simply "lithography tool" 200), the measurement station MEA is shown at 202, and the exposure station EXP is shown at 204. The control unit LACU is shown at 206. In this example, each substrate accesses both the measurement station and the exposure station to have an applied pattern. For example, in an optical lithography apparatus, a projection system is used to transfer a product pattern from a patterning device MA onto a substrate using regulated radiation and the projection system. This is achieved by forming an image of the pattern in a radiation-sensitive resist material layer.

[0026] The term "projection system" as used herein should be interpreted broadly to encompass any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic, electrostatic optical systems, or any combination thereof, adapted to the exposure radiation used, or to other factors such as the use of immersion or vacuum. The patterning apparatus MA can be a mask or stencil that imparts a pattern to a beam of radiation transmitted or reflected by the patterning apparatus. Well-known operating modes include step mode and scan mode. It is known that projection systems can cooperate in various ways with the substrate and the support and positioning systems of the patterning apparatus to apply a desired pattern to a number of target portions across the substrate. Programmable patterning apparatus can be used instead of masks with fixed patterns. For example, the radiation can include electromagnetic radiation in the deep ultraviolet (DUV) or extreme ultraviolet (EUV) bands. This disclosure also applies to other types of lithography processes, such as imprint lithography and, for example, direct-write lithography via electron beams.

[0027] The photolithography apparatus LA described herein can be used in methods for manufacturing semiconductor devices. A method for manufacturing a semiconductor device includes receiving a substrate W having a photoresist layer. The method further includes guiding a radiation beam from a radiation source to transfer a pattern from a mask onto the photoresist layer. This can be achieved using a patterning apparatus configured to form a patterned radiation beam and apply the patterned radiation beam to the photoresist layer. The method for manufacturing a semiconductor device also includes the step of removing a portion of the photoresist layer to form a pattern on the substrate W.

[0028] The substrate W may be made of silicon or other semiconductor materials. Alternatively or additionally, the substrate W may include other semiconductor materials, such as germanium (Ge) or carbon (C). In some embodiments, the semiconductor substrate is made of compound semiconductors, such as III-V compound semiconductors, II-V compound semiconductors, and / or any suitable group IV material integrated. In some embodiments, the substrate W may be a silicon-on-insulator (SOI) or germanium-on-insulator (GOI) substrate.

[0029] Semiconductor devices fabricated from substrate W can have a variety of device elements. Examples of semiconductor device elements formed on substrate W include transistors (e.g., planar or non-planar metal-oxide-semiconductor field-effect transistors (MOSFETs), bipolar junction transistors (BJTs), high-voltage transistors, high-frequency transistors, etc.), diodes, CMOS image sensors, passive devices, and / or other suitable elements. Various processes can be performed to form semiconductor device elements, such as deposition, etching, implantation, epitaxial growth, polishing, thermal processing, and / or other suitable processes. In some embodiments, substrate W is coated with a photoresist layer sensitive to the DUV or EUV bands.

[0030] The photolithography apparatus control unit (LACU) controls all movements and measurements of various actuators and sensors to receive data from the substrate (W) and mask (MA) and perform patterning operations. The LACU also includes signal and data processing capabilities to perform desired calculations related to the operation of the apparatus. In practice, the LACU is implemented as a system comprising many subunits, each handling real-time data acquisition, processing, and control of subsystems or components within the apparatus.

[0031] Before the pattern is applied to the substrate at the Exposure Station (EXP), the substrate is processed at the Measurement Station (MEA) so that various preparation steps can be performed. Preparation steps may include mapping the surface height of the substrate using a level sensor and measuring the position of alignment marks on the substrate using an alignment sensor. The alignment marks are nominally arranged in a conventional grid pattern. However, due to inaccuracies in mark creation and substrate deformation that occurs throughout the substrate processing, these marks deviate from the ideal grid. Therefore, in practice, in order for the apparatus to print product features in the correct position with extremely high precision, in addition to measuring the position and orientation of the substrate, the alignment sensor must also measure the position of multiple marks across the substrate area in detail. The apparatus can be of a so-called dual-stage type, with two substrate stages, each with a positioning system controlled by a control unit (LACU). While one substrate on one stage is exposed at the Exposure Station (EXP), the other substrate can be loaded onto the other substrate stage at the Measurement Station (MEA) so that various preparation steps can be performed. Therefore, measuring the alignment marks is very time-consuming, and providing two substrate stages allows for a significant increase in the throughput of the apparatus. If the position sensor IF cannot measure the position of the substrate stage at both the measurement and exposure stations, a second position sensor can be provided to enable tracking of the substrate stage position at both stations. For example, a lithography apparatus LA can be a so-called dual-stage type, having two substrate stages and two stations (exposure station and measurement station), between which the substrate stages can be interchanged.

[0032] Within the production facility, apparatus 200 constitutes part of a "lithography unit" or "lithography cluster," which also includes a coating apparatus 208 for applying photoresist and other coatings to a substrate W for patterning by apparatus 200. On the output side of apparatus 200, a baking apparatus 210 and a developing apparatus 212 are provided for developing the exposed pattern into a physical resist pattern. Between all these apparatuses, a substrate handling system is responsible for supporting the substrates and forwarding them from one apparatus to the next. These apparatuses (generally referred to collectively as tracks) are controlled by a track control unit, which in turn is controlled by a management control system SCS, which in turn controls the lithography apparatus via a lithography apparatus control unit LACU. Thus, these different apparatuses can be operated to maximize throughput and processing efficiency. The management control system SCS receives recipe information R, which provides very detailed specifications for the steps performed to create each patterned substrate.

[0033] Once the pattern is applied and developed in the photolithography unit, the patterned substrate 220 is transferred to other process devices, such as those described at 222, 224, and 226. A wide range of process steps are performed by various devices in a typical manufacturing facility. For example, in this embodiment, device 222 is an etching station, and device 224 performs a post-etch annealing step. Further physical and / or chemical process steps are applied in other devices, 226, etc. Several types of operations are required to fabricate actual devices, such as material deposition, modification of surface material properties (oxidation, doping, ion implantation, etc.), chemical mechanical polishing (CMP), etc. In practice, device 226 represents a series of different process steps performed in one or more devices. As another example, devices and process steps can be provided to implement self-aligned multiple patterning, thereby generating multiple smaller features based on the precursor pattern formed by the photolithography device.

[0034] As is well known, the fabrication of semiconductor devices involves multiple repetitions of such processes to build device structures with appropriate materials and patterns layer by layer on a substrate. Therefore, the substrate 230 arriving at the photolithographic cluster can be a newly prepared substrate or a substrate that has been previously processed completely in that cluster or in another apparatus. Similarly, depending on the desired process, after leaving apparatus 226, the substrate 232 can be returned for subsequent patterning operations in the same photolithographic cluster, it can be sent to a different cluster for patterning operations, or it can be a finished product awaiting dicing and packaging.

[0035] Each layer of the product structure requires a different set of process steps, and the apparatus 226 used in each layer can be completely different in type. Furthermore, even if the process steps to be performed by apparatus 226 are nominally the same, in large facilities, multiple supposedly identical machines can operate in parallel to perform step 226 on different substrates. Minor differences in setup or malfunction of these machines may mean that they affect different substrates in different ways. Even steps that are relatively common to each layer, such as etching (apparatus 222), can be performed by multiple nominally identical but parallel-operating etching apparatuses to maximize throughput. Moreover, in practice, different layers require different etching processes (e.g., chemical etching, plasma etching) depending on the details of the material to be etched and specific requirements (e.g., anisotropic etching).

[0036] As mentioned earlier, preceding and / or subsequent processes can be performed in other lithography apparatuses, and even in different types of lithography apparatuses. For example, some layers with extremely high requirements for parameters (such as resolution and overlay) in device fabrication processes can be performed in more advanced lithography tools than other layers with lower requirements. Therefore, some layers can be exposed in immersion lithography tools, while others are exposed in "dry" tools. Some layers can be exposed in tools operating at DUV wavelengths, while others are exposed using EUV wavelength radiation.

[0037] To ensure correct and consistent exposure of substrates by the photolithography apparatus, it is necessary to inspect the exposed substrates to measure characteristics such as overlay error between subsequent layers, line thickness, and critical dimension (CD). Therefore, the manufacturing facility, where the photolithography unit (LC) is located, also includes a metrology system that receives some or all of the substrates (W) that have been processed in the photolithography unit. The metrology results are provided directly or indirectly to the management and control system (SCS). If an error is detected, the exposure of subsequent substrates can be adjusted, especially if the metrology can be completed quickly enough so that other substrates in the same batch have not yet been exposed. Furthermore, exposed substrates can be stripped and reworked to improve yield, or discarded to avoid further processing on substrates known to be defective. In cases where only some target areas of the substrate are defective, further exposure can be performed only on those good target areas.

[0038] Figure 1Measurement apparatus 240 is also shown, which is provided to measure parameters of the product at a desired stage in the manufacturing process. A common example of a measurement station in modern lithography manufacturing facilities is a scatterometer (e.g., a dark-field scatterometer, an angle-resolved scatterometer, or a spectrophotometer), which can be applied prior to etching in apparatus 222 to measure the characteristics of the developed substrate at 220. Using measurement apparatus 240, it can be determined that important performance parameters (e.g., overlay or critical dimension (CD)) do not meet the accuracy requirements specified in the developed photoresist. Prior to the etching step, there is an opportunity to strip the developed resist and reprocess the substrate 220 through the lithographic cluster. Measurement results 242 from apparatus 240 can be used to maintain accurate execution of patterning operations in the lithographic cluster, with minor adjustments over time by the management control system SCS and / or control unit LACU 206, thereby minimizing the risk of product manufacturing defects and rework.

[0039] In addition, measurement device 240 and / or other measurement devices (not shown) may be applied to measure the characteristics of the processed substrates 232, 234 and the incoming substrate 230. This measurement device can be used on the processed substrate to determine important parameters, such as overlay or CD.

[0040] The measuring device suitable for use in embodiments of the present invention is Figure 2 As shown in (a). This is purely an exemplary measurement, and any suitable measurement apparatus used for measuring process parameters, such as overlays on a substrate, can be used. The target T and the diffracted rays used to irradiate the target are shown in [the diagram / image]. Figure 2(b) describes this in more detail. The measurement apparatus described belongs to a type known as a dark-field measurement apparatus. The measurement apparatus can be a stand-alone device or incorporated into a lithography apparatus LA (e.g., in a measurement station) or lithography unit LC. The optical axis with multiple branches running through the apparatus is indicated by the dashed line O. In this apparatus, light emitted by source 11 (e.g., a xenon lamp) is guided onto the substrate W via a beam splitter 15 through an optical system comprising lenses 12, 14 and objective lens 16. These lenses are arranged in a 4F arrangement in a double sequence. Different lens arrangements can be used, as long as they still provide an image of the substrate to the detector and simultaneously allow access to the intermediate pupil plane for spatial frequency filtering. Thus, the range of angles at which radiation is incident on the substrate can be selected by determining the spatial intensity distribution within the plane presenting the spatial spectrum of the substrate plane (here referred to as the (conjugate) pupil plane). Specifically, this can be achieved by inserting an aperture plate 13 of suitable form between lenses 12 and 14 within the plane of the rear-projected image of the objective lens pupil plane. In the illustrated example, the aperture plate 13 has different forms, labeled 13N and 13S, allowing for the selection of different illumination modes. The illumination system in this example forms an off-axis illumination mode. In the first illumination mode, aperture plate 13N provides off-axis illumination from a direction designated "north" for descriptive purposes only. In the second illumination mode, aperture plate 13S is used to provide similar illumination, but from a relative direction designated "south". Other illumination modes can be achieved by using different apertures. The remaining pupil surface is ideally dark, as any unwanted light outside the desired illumination mode would interfere with the desired measurement signal.

[0041] like Figure 2 As shown in (b), target T is placed with substrate W perpendicular to the optical axis O of objective lens 16. Substrate W may be supported by a support (not shown). Measurement radiation ray I incident on target T from an angle off-axis O produces a zero-order ray (solid line 0) and two first-order rays (dotted line +1 and double-dotted line -1). It should be remembered that for a small target under overload, these rays are just one of many parallel rays overlaid on the substrate region, which includes the measurement target T and other features. Due to the finite width of the aperture in plate 13 (sufficient to allow a useful amount of light), incident ray I will actually occupy a certain angular range, and diffracted rays 0 and +1 / -1 will be extended to some extent. Depending on the point spread function of the small target, each +1 and -1 order will be further extended within a certain angular range, rather than a single ideal ray as shown. Note that the grating pitch and illumination angle of the target can be designed or adjusted so that the first-order rays entering the objective lens are closely aligned with the central optical axis. Figure 2 The rays illustrated in (a) and 2(b) are shown slightly off-axis, purely to make them easier to distinguish in the figure.

[0042] At least the 0th and +1st orders of the diffraction from the target T on the substrate W are collected by objective lens 16 and guided back by beam splitter 15. (Back) Figure 2 (a) Both the first and second illumination modes are described, and are labeled North (N) and South (S) by specifying their radially opposite apertures. When the incident ray I for measuring radiation comes from the north side of the optical axis, i.e., when the first illumination mode is applied using aperture plate 13N, the +1 diffraction ray, labeled +1 (N), enters the objective lens 16. Conversely, when the second illumination mode is applied using aperture plate 13S, the -1 diffraction ray (labeled -1 (S)) is the ray entering the lens 16.

[0043] The second beam splitter 17 divides the diffracted beam into two measurement branches. In the first measurement branch, the optical system 18 uses the zeroth-order and first-order diffracted beams to form the diffraction spectrum (pupil image) of the target on the first sensor 19 (e.g., a CCD or CMOS sensor). Each diffraction order illuminates a different point on the sensor, allowing image processing to compare and contrast the orders. The pupil image captured by the sensor 19 can be used for a variety of measurement purposes, such as reconstruction used in the methods described herein. The pupil image can also be used for focusing measurement devices and / or intensity measurements of the normalized first-order beam.

[0044] In the second measurement branch, optical systems 20 and 22 form an image of the target T on sensor 23 (e.g., a CCD or CMOS sensor). In this second measurement branch, an aperture stop 21 is provided in a plane conjugate to the pupil plane. The aperture stop 21 blocks the zero-order diffraction beam so that the target image formed on sensor 23 is formed only by a -1 or +1 first-order beam. The image captured by sensors 19 and 23 is output to an image processor PU, the function of which depends on the specific type of measurement performed. Note that the term "image" is used broadly here. If only one of the -1 or +1 orders exists, an image of the grating lines will not be formed.

[0045] Figure 2 The specific forms of the aperture plate 13 and field stop 21 shown are purely illustrative. In another embodiment of the invention, coaxial illumination of the target is used, and an aperture stop with an off-axis aperture is used to transmit essentially only a first-order diffraction beam to the sensor. In other embodiments, second-order, third-order, and higher-order beams ( Figure 2 (Not shown in the figure) can be used in measurements to replace a first-order beam or as a supplement to a first-order beam.

[0046] The target T may contain several gratings with different offsets to facilitate measurement of the overlay between layers forming different portions of the composite grating. The gratings may also be oriented differently to diffract incident radiation in the X and Y directions. In one example, the target may include two X-direction gratings with offsets of +d and -d, and a Y-direction grating with offsets of +d and -d. Individual images of these gratings can be identified in the image captured by sensor 23. Once the individual images of the gratings are identified, the intensity of these individual images can be measured, for example, by averaging or summing the intensity values ​​of selected pixels within the identified region. The intensity and / or other characteristics of the images can be compared. These results can be combined to measure different parameters of the lithography process.

[0047] In a single exposure of a photolithography apparatus, the maximum area that can be exposed is defined by its maximum scan field area. This is defined by the exposure slit width in a first direction (typically designated as the x-direction) and the maximum scan length in an orthogonal direction (typically designated as the y-direction) of the same (substrate) surface. In some cases, the die area (the substrate area of ​​the fabricated device, referred to herein as the substrate field area or substrate region area) is larger than the maximum scan field area. In such cases, some or all layers of the device need to be exposed on the substrate region (or substrate field) in multiple (e.g., two) independent adjacent exposures. For example, a substrate region twice the maximum scan field area can be exposed in two exposures: a first exposure using a first mask containing a first pattern for printing a first substrate sub-region (e.g., a first half on the substrate area) and a second mask containing a second pattern for printing a second sub-region (e.g., a second half, although there may be a small overlap, adjacent to the first half to form the complete die layer) on the substrate. These two halves can be referred to as having been "stitched" together, and this process is sometimes referred to as in-die stitching.

[0048] The reasons for die splicing can be twofold. First, die sizes are increasing to allow dies to be larger than the field size of conventional lithography apparatuses. Second, newer or proposed EUV lithography apparatuses with large numerical apertures (NAs) have reduced field sizes; more specifically, half-field sizes, meaning the field size is half the conventional field size in one of the dimensions of the substrate plane.

[0049] As previously described, metrology equipment is used to measure one or more performance parameters (e.g., overlay) on the processed substrate and to determine process corrections designed to minimize overlay errors in subsequent substrates and / or subsequent layers on the same substrate. These process corrections are typically implemented by the lithography apparatus in a feedback loop.

[0050] For stitched dies, the positioning of each sub-region of the stitched die (i.e., a stitched die comprising two or more sub-regions stitched together, typically exposure fields) relative to other sub-regions of the stitched die is an important positioning metric beyond conventional overlay (position relative to one or more previously exposed layers). Measuring the position of a sub-region within a stitched die relative to one or more other sub-regions is referred to in this paper as "stitching overlay," a positioning metric distinct from conventional true overlay (another positioning metric) because it involves relative positioning within a single layer.

[0051] Stitching overlay can be monitored and thus controlled in a manner similar to conventional overlay, for example, by measuring a target (referred to herein as a stitching target) comprising a first structure exposed with a first sub-region to be stitched and a second structure exposed with a second sub-region to be stitched. For example, the first and second structures may comprise respective frames (e.g., in a frame-within-a-frame arrangement or a neighboring frame arrangement). Such a stitching target may comprise a first image of a frame in the first sub-region (e.g., at its edge) formed within or near a second image of a frame in the second sub-region (e.g., at its edge), the two sub-regions overlapping in the boundary region formed by the stitching target. Alternatively, the two images may each comprise grating structures designed to be staggered when imaged in the boundary region. Misalignment of such a staggered target will manifest as asymmetry, which can then be measured similarly to an overlay target, or the position of the second structure can be determined in vector form relative to the first structure. Such a stitching target can be formed on top of another grating in another layer (or another grating can be formed on top of it) to provide a stitching overlay target for which overlay relative to other layers can also be measured.

[0052] Figure 3An exemplary stitching core 300 is illustrated, comprising four sub-regions 310a, 310b, 310c, and 310d. Two sub-regions may (at least partially) overlap to define a stitching boundary region 320 for stitching the sub-regions. Within the stitching boundary region 320 are stitching targets 330a, 330b, 330c, and 330d. Stitching targets 330a and 330b are shown in greater detail. Each of these stitching targets 330a, 330b, 330c, and 330d includes a double-frame structure, each frame being exposed with a different sub-region. Referring to stitching target 330a, a gray frame is formed by sub-region 310d, and a black frame is formed by sub-region 310a. Similarly, for stitching target 330b, a gray frame is formed by sub-region 310b, and a black frame is formed by sub-region 310a. Dashed boxes indicate the nominal positions of the individual frames. The arrows represent vectors describing the positional differences from the first box (structure) to the second box (structure), from which the vectors of positional differences can be measured and positional corrections can be determined (e.g., in a feedback method). Note that this is only an exemplary arrangement, and the splicing target or splicing core may differ from what is shown (e.g., a common arrangement may include two half-field sub-regions spliced ​​together).

[0053] Figure 4 The exposure sequence for exposing substrates in a multi-channel configuration to obtain spliced ​​dies is described. A first wafer stage 400 under atmospheric pressure, a second wafer stage 405 under vacuum, and a wafer stage arrangement 410 also under vacuum are shown (vacuum assumes the use of an EUV apparatus; however, the concepts disclosed herein are not limited to EUV, and therefore all operations can be performed under atmospheric pressure). The wafer stage arrangement 410 may include a measurement side or measurement station 415 and an exposure side or exposure station 420 (although the concept here is not limited to a dual-stage arrangement). A first chuck 417 and a second chuck 422 transport each substrate within the wafer stage arrangement 410.

[0054] The gray arrows depict a typical single-channel sequence in which each substrate is pre-aligned 425, loaded 430, admitted to a second wafer stage 405 via a loading lock 435, further pre-aligned 445, and loaded onto a stage 450. Subsequent measurements (fine alignment) and exposures are performed on the measurement side 415 and the exposure side 420, respectively. The substrate is unloaded from the stage 460 to exit the vacuum chamber 405, then unloaded 470 and discharged 475.

[0055] The black arrows depict the multi-channel exposure sequence used for exposing the splicing chip, where each substrate is loaded, measured, and exposed two or more times. To maximize the throughput of multi-mask exposures, a new hardware component, called a storage bank 465, can be used to store substrates between exposures. Thus, at the end of the first pass (or any pass except the last), the substrate is unloaded 470, held in the storage bank 465 (e.g., stored for a few minutes, during which time the mask can be replaced), then aligned 425 and loaded 430 to begin another pass.

[0056] If a series of fields are exposed at different times, residual errors generated in the first exposure series will affect the stitching quality if not considered in advance.

[0057] Furthermore, when using a multi-channel approach, a single pre-defined alignment strategy (a fixed set of marker types, sampling, color formulas, and models) for all channels may no longer be able to accurately measure and predict substrate deformation, as the alignment marks and wafer may exhibit different deformations each time they pass the measurement / exposure side.

[0058] Manufacturing apparatuses such as exposure or lithography apparatuses (and / or related equipment) typically generate process error information or data related to the manufacturing or exposure process, for example, related to various modules and / or actions. Such process error data may in particular include lens model error data (e.g., lens model residual data), lens fingerprint data (lens error distribution), actuation error or residual data (e.g., servo error data), lens overpressure error data, alignment data, and alignment residual data (residual data after fitting the alignment model).

[0059] This paper proposes using such process error data (e.g., process error data generated during manufacturing or photolithography exposure processes, and / or generated within the manufacturing / photolithography apparatus when performing at least a first exposure sequence to expose at least one first sub-region of a spliced ​​die) to determine (e.g., predict) an on-product or positional measurement error in the first sub-region, thereby determining a correction to compensate for and / or mitigate the determined on-product or positional measurement error when exposing at least one second sub-region of the spliced ​​die. This method can then be applied to the correction when performing at least a second exposure sequence to expose at least one second sub-region of the spliced ​​die region. For example, the correction can be determined to match any overlay and / or positional errors from the at least one first sub-region.

[0060] Therefore, a method for determining a correction is disclosed, the correction being used to control at least one manufacturing apparatus used in a manufacturing process for providing a structure to at least one region on a substrate, said region including at least one first sub-region and a second sub-region in a common layer; the method comprising: acquiring process error data related to the manufacturing process when forming the first sub-region on the substrate; determining a first on-product error based on the process error data, said on-product error being related to an error in the formation of the first sub-region; and determining a correction to the manufacturing process based on the on-product error when forming the second sub-region.

[0061] The product-related errors may include errors in at least one positioning metric (such as the positioning or placement of structures within the first sub-region) to minimize the determined correction for splicing overprinting errors (relative positioning errors of one sub-region relative to at least one other sub-region of the spliced ​​core). Alternatively or additionally, the positioning metric may be (e.g., conventional) overprinting relative to another layer. Therefore, the method may include matching the overprinting (errors) of the two sub-regions. The method may also include co-optimized corrections for splicing overprinting and conventional overprinting (which may optionally be weighted to favor one or the other overprinting type).

[0062] Figure 5 This is a flowchart describing a method according to one embodiment. Process error data 500 associated with a first exposure sequence is acquired, for example, by exposing (e.g., repeatedly) a first sub-region on a substrate, each first sub-region including a first portion of a spliced ​​die. Process error data 500 may include, for example, actuation error data 505 (e.g., actuation residual data or servo error / residual data) and / or lens error data 510. Actuation error data 505 may include, for example, one or more of the following: servo MA (moving average actuation residual data), servo dx (x-displacement actuation residual data), servo dy (y-displacement actuation residual data), or servo dRz (rotation actuation residual data about the z-axis). Lens error data 510 may include, for example, aberration errors (aberration residuals) actuated during the exposure of the first sub-region, expressed, for example, in the form of a Zernike function. Other types of error data may also be used, such as alignment residual data, which may be used in this method.

[0063] In step 520, the product error associated with the exposure of the first sub-region (e.g., stitching and / or conventional overlay error) can be determined or predicted based on error data 500. This product error can be determined based on actuation error data 505 obtained from the corresponding servo driver. Lens error data 510 can be converted into product error using the associated overlay Zernike sensitivity 515. Based on the determined product error, a correction 535 can be determined 530 to improve the stitching of the second sub-region to be exposed with the first sub-region (e.g., to match the product errors of the first and second sub-regions).

[0064] The correction determination step 530 may also be subject to rules and / or constraints 525, such as possible and / or permissible actuation, permissible errors in field distortion, and / or other overlays (e.g., constraints may be imposed on this pair for stitching overlay if regular overlay is matched to the sub-regions by correction, and vice versa). For example, specific actuation capabilities may be specified and / or prohibited; for example, specifying field translation to be used to correct lens errors in horizontal stitching. In another example, the maximum amount of stitching correction may be specified, for example, in absolute terms (e.g., nm) or relative terms (percentage). This can be used to balance regular overlay (if relevant) or image distortion with stitching overlay. This balancing can be done for each actuation parameter, for example, for x-translation Tx and y-translation Ty for each sub-region, respectively. Furthermore, it should be understood that some lens-related errors (e.g., x-magnification (Mag x)) contribute twice as much to the stitching error, and therefore correction of such errors may be superior to correction of other errors.

[0065] The determined correction 535 may be a feedforward correction, which is actuated during the second exposure sequence 540 to expose (e.g., repeatedly) a second sub-region, each second sub-region comprising a second portion of the splicing filament. Any actuation error in the splicing can then be reported.

[0066] In this embodiment, (e.g., the second) exposure sequence can be determined or optimized to ensure sufficient computation time for determining errors on the product and subsequent corrections. Such an exposure sequence can provide sufficient computation time while maintaining a stable queue depth (e.g., currently 5 sub-regions / fields). It is worth noting that mask replacement is typically involved when exposing the first and second series of sub-regions, significantly increasing the budgeted computational workload.

[0067] In embodiments, alignment data (e.g., measured / pre-modeled and / or modeled alignment data) can be fed forward from the first exposure sequence to the second exposure sequence. This allows alignment measurement and / or model data from different exposure sequences to be blended. This can mean that the measurement workload (number of alignment marks) of the second exposure sequence can be reduced, resulting in improved throughput when exposure is measurement-side limited, such as smaller exposure fields (e.g., half-fields with half exposure times) or using low doses. In extreme cases, it should be assumed / determined that the in-plane deformation between exposure sequences is constant, in which case the complete model results from the first exposure sequence can be used for the second exposure sequence, and equivalent steps of the measurement sequence of the second exposure sequence are skipped (e.g., pre-alignment and / or fine alignment). Alternatively, this alignment feedforward can be used to improve alignment, for example, to capture dynamic deformation. When process-induced wafer deformation remains constant / stable between sequences, wafer model results from the first sequence can be reused, and the second sequence measurements can focus on capturing dynamic deformation (e.g., wafer reloading, lens / mask heating) by measuring more markers optimized for this purpose or enabling in-situ adjustments (e.g., measuring additional markers on the splice area to improve splice overlay).

[0068] In another embodiment of the method of the invention, more than one predetermined alignment strategy (e.g., marker type, color formulation, sampling scheme, and alignment model) is defined and / or used for each exposure sequence. The method may also include using and / or defining alignment strategies and / or configurations of the lithography apparatus for each pass or exposure sequence, including when a single layer of the substrate is exposed in multiple pass or exposure sequences. Advantageously, this embodiment allows for capturing dynamic variations between exposure sequences and provides better wafer alignment accuracy. Dynamic variations can arise from substrate reloading, different machine component dynamics, lens / mask heating, marker asymmetry, etc. A non-limiting example of this embodiment is that when a high-NA EUV exposure layer is aligned with a previous high-NA EUV exposure layer, the AL markers on the first exposed layer may suffer from different marker asymmetries due to different marker types, exposure settings, marker-to-device offset, and imaging-induced asymmetries. Therefore, when both layers are aligned, different color formulations or in-field models for each pass can effectively capture differences in marker asymmetry and in-field fingerprints between two exposure sequences.

[0069] In another embodiment, the method of the invention further includes using or mixing measurement / model data from different exposure sequences. Advantageously, this embodiment reduces the amount of AL markers to be measured in the second exposure sequence, resulting in improved throughput of the lithography apparatus when the exposure sequence throughput is limited by the measurement side. In another embodiment, the method further includes reusing modeling results from the first exposure sequence and skipping specific steps of the measurement sequence in the second exposure sequence when the in-plane deformation remains constant between passes. In this embodiment, it is proposed to use additional time to measure a specific region of interest to obtain a better model of the fingerprint within a region.

[0070] In another embodiment, the method of the invention further includes performing simulations of different alignment strategies within the exposure sequence to obtain the effects of overlay, EPE, CD, and CDU on the processed substrate. Advantageously, this embodiment provides an indication of the degree of dynamic deformation between exposure sequences, and whether different alignment strategies need to be applied to each exposure sequence and optimized collaboratively. It also provides the advantage of evaluating whether measurements from the first exposure sequence can be reused in a second exposure sequence to improve throughput.

[0071] In certain embodiments, the same concepts in the preceding paragraph can be further extended to other functions in the measurement sequence or other data measurements within the lithography apparatus, such as data measured by a horizontal sensor: substrate leveling and / or substrate height distribution and / or substrate z-axis distribution.

[0072] In the embodiments disclosed herein, conventional overlay and / or stitched overlay corrections can be determined as coefficients (sometimes referred to as k-parameters) of a polynomial in the best-fit method, such that the correction is based on minimizing the corresponding measured conventional overlay and / or stitched overlay (e.g., the average value over the fitted region) when the polynomial is applied. This optimization can be performed separately for conventional overlay or stitched overlay (e.g., completely separately, or optimizing one with one or more constraints on the other), or co-optimization of these different overlays can be performed. The determined coefficients can be fed back to the lithography apparatus in the form of a sub-formula characterized by the coefficients.

[0073] Specific examples of the proposed method disclosed may include collaborative optimization of stitching errors in the evaluation function of trajectory calculation. Stitching errors may originate from at least two sources. The first source may be discontinuous correction requests, whereby if the requested corrections differ for each sub-region and the actuation error is not zero, the residues at the boundaries between sub-regions will not perfectly match, leading to stitching errors. The second source may be scanner actuation, where the correction potential is greater at the top and bottom edges of the field due to scan-in / scan-out effects.

[0074] In this embodiment, it is proposed to reduce the stitching error by including it in the evaluation function of the trajectory calculation. The stitching error can be represented as the difference between the second actuation error data or actuation residue of the second sub-region exposure and the first actuation error data or actuation residue of the first sub-region exposure. Thus, the first sub-region exposure is performed normally, without considering stitching, while the second sub-region exposure utilizes the actuation residue of the first exposure to improve the stitching error (stitching overlay error). ,in and These are the actuation residues from the first and second sub-region exposures, respectively.

[0075] In a specific example, the actuation error evaluation function can take the following form: in, For the model matrix, Let the vector be the actuation distribution coefficient. This is the deformation value vector (for each grid point). This is for weighting.

[0076] This method is not limited to improving stitching errors in the overlay domain. It can also be used for stitching focal points, MSDs, or higher-order Zernike.

[0077] Thus, the method disclosed herein determines the correction of the (half) field to be exposed, which predicts the error generated in one or more exposed (half) fields, so that the stitching error at least at the boundary can be reduced.

[0078] Overlay correction is determined (as far as possible) for actuation within the lithography apparatus. However, when different lithography apparatuses are used in different layers (e.g., a first lithography apparatus has an exposure field half the size of the conventional exposure field, and a second lithography apparatus has an exposure field the full size of the conventional exposure field, each with different correction and / or actuation capabilities), the determined correction for each sub-region in the first layer can introduce patterns that cannot be corrected in the second layer (e.g., any subsequent layer). Alternatively or additionally, the relative position or overlay of sub-regions in the first layer is also an important parameter, which, if not properly controlled, can lead to irregularities in the splicing area (the overlapping area of ​​two sub-regions).

[0079] Additional embodiments will be described, in which the correction of each sub-region of the two sub-regions to be spliced ​​together is co-optimized or co-determined, rather than determined as a feedforward correction from one sub-region to another. The method may determine the correction (e.g., feedback correction) based on overlay data measured from one or more substrates in a previous batch (e.g., for batch correction). Alternatively, the method may be performed on each substrate (e.g., to make a rework decision). Advantageously, this embodiment reduces the likelihood of discontinuities and / or poor overlay performance relative to subsequent layers in the splicing area between the two sub-regions, thereby reducing the number of defective dies.

[0080] This method can simultaneously optimize overlay correction for each sub-region, while also considering stitching region performance and / or correction for one or more subsequent layers. This can be achieved by applying stitching region performance constraints and / or penalties to the relevant optimizations. Thus, the method can include determining co-optimization for two or more sub-regions constrained by stitching region (or boundary) performance, where the stitching region can describe the overlap area of ​​the two sub-regions. More generally, the proposed method can optimize any process correction (including but not limited to overlay, dosage, focus, other parameters of interest, or any combination thereof).

[0081] Alternatively or additionally, co-optimized correction can take into account the actuation capability of one or more subsequent layers (e.g., the actuation capability of the lithography apparatus used to expose the one or more subsequent layers). This can be achieved by one or both of constraining the objective function and / or adding a penalty term to the objective function. For example, constraints and / or penalties can be imposed on performance across the stack, such as overlay or other parameters of concern relative to one or more subsequent layers, and in particular, one or more subsequent layers are determined by different correction capabilities and / or field sizes. Specifically, two or more sub-regions can be exposed in a first layer by a first lithography apparatus having a first correction capability and / or a first field size (e.g., a field size defining the size of the sub-regions), and the one or more subsequent layers can be exposed in a second layer by a second lithography apparatus having a second correction capability and / or a second field size (e.g., a field size larger than the sub-region size, such as twice, 2.5 times, or 3.5 times the size of the first layer sub-regions). For example, the proposed high-NA EUV apparatus has a field size that is half the field size of many existing DUV or EUV apparatuses. Differences in correction capabilities can stem from, for example, one or more of the following: different actuation parameterizations, different actuation capabilities, and / or different modeling capabilities / models used.

[0082] The splicing region performance penalty and / or constraint can be a soft constraint that constrains and / or penalizes differences in residual values ​​within the splicing region (overlay). The specific example described below does not explicitly limit the splicing error, but rather uses the splicing variable, which is used as a penalty in the objective function. To punish splicing and overlay errors.

[0083] This splicing variable This can be included in the objective function as a concatenation regularization term (e.g., as a normalization value), in addition to the usual residual minimization. Optionally, the effect size or weight of this concatenation overlay penalty can be determined via concatenation hyperparameters. To adjust. The splicing hyperparameter values ​​can be automatically determined based on the use case. Optionally, a splicing dead zone threshold can be set. It can also be included in the splice overlay penalty (or constraint), which defines the minimum relevant difference in the splice region residue, below which the splice region residue can be considered unimportant.

[0084] Regarding stack-through settings, stack-through penalties and / or constraints can be imposed, for example, via variables that include stack-through properties. The stack-through regularization term in the objective function. For example, stack-through penalties and / or constraints can be used with concatenated variables. How to penalize similarity in target values ​​when splicing overlays, via (e.g., normalization) through stacked variables. Penalty target value. This through-stack penalty may include further soft constraints that constrain the correction to be applied to the first layer (e.g., comprising two or more sub-regions, each exposed in an independent exposure) to enable subsequent layers to follow the first layer exposure (at least to some extent or within an acceptable margin), which are to be exposed by different lithography devices with different correction capabilities. Thus, the through-stack penalty and / or constraint can penalize the difference between the first layer correction described in terms of the correction capability of the first layer and the subsequent layer correction described in terms of the correction capability of one or more subsequent layers. The through-stack penalty and / or constraint may also include a through-stack hyperparameter ν to set the constraint weights.

[0085] Through stack dead zone threshold (For example, user-specified) can be limited, and this threshold defines the minimum correlated difference across the stack remnants. In this context, the subsequent layer design matrix... It can be constructed, for example, using the union (or a subset thereof) of the optimized meshes of the first-layer sub-region fields. More generally, the subsequent layer design matrix... It can contain any suitable "through stacked mesh", which does not need to be associated with (multiple) optimized meshes.

[0086] In one illustrative embodiment, the evaluation function may take the form where the splice region performance and / or penalty or constraint, and the through-stack penalty and / or constraint, are each penalized via their respective normalized error terms, rather than constraining the error; for example: Constraints / regularization include: and [First Layer Actuation] [Subsequent layers activated] [Punishment for splicing and overlaying] Penalty for stacking through And among them (except for the items that have been specified), , It is the design matrix of the first and second sub-regions of the first layer. , It is the correction parameters (vector of actuation distribution coefficients) for the first and second sub-regions. , These are the process error data (overlay data) for the first and second sub-regions. , , , This describes the first-level design matrix and process error data used only in the splicing area (boundary area) (where the sub-regions are specified as previously). and These are the design matrices and correction parameters for subsequent layers. , , , , , Actuation constraints for actuating the first sub-region, the second sub-region, and subsequent layers are described, and , Norms were defined for the splicing overlay penalty and the through-stack penalty, respectively.

[0087] It can be understood that, although the specific evaluation function example given is only described for two sub-regions and only two layers per field, this description can be generalized to more sub-regions and / or more layers per field. Furthermore, although the parameter of interest is overlay, it can also be applied to other parameters of interest.

[0088] Note that this stitching overlay penalty and / or constraint can also be applied to Equation 1 above. Furthermore, the through-stack penalty and / or constraint can also be applied to Equation 1, although this can be applied separately for each sub-region optimization.

[0089] Several improvements related to the splicing area of ​​the splicing core will now be described, and these improvements can be applied to any of the embodiments described above. In the splicing area, the pattern may have discontinuities, which can degrade the electrical performance of the device.

[0090] Figure 6 This is a schematic diagram illustrating the exposure control method for the first stitching area. The diagram shows a first sub-region 600 and a second sub-region 605, with a stitching area 610 defined by the overlap of the first and second sub-regions 600 and 605. Note that the first and second sub-regions 600 and 605 are exposed in a common layer. In an embodiment, each sub-region is exposed using its own different mask; for example, the first sub-region 600 is exposed with mask A RET A, and the second sub-region 605 is exposed with mask B RET B (although the same mask can be used for both sub-regions). Below this, the set focus distribution is shown, which describes the focus settings during the exposure of the first sub-region 600, the second sub-region 605, and the stitching area 610. In this simplified example, the applied focus distribution includes individual settings 615a and 615b for the exposure of the first sub-region 600 (gray line) and the second sub-region 605 (black solid line) outside the stitching area 610, respectively. However, it was proposed to expand the focus offset (or defocus) only within the stitching area 610, so that each exposure is performed at two different focus levels. As a result, a larger depth-of-focus tolerance is obtained.

[0091] In one particular embodiment, relative focus offsets 620a and 620b are proposed to be applied during exposure of the first sub-region 600 and the second sub-region 605 within the stitching area, respectively. Relative focus offsets, relative to the nominal focus setting outside the stitching area, may include defocus or focus offsets of the same magnitude but different directions for each of the first sub-region 600 and the second sub-region 605. Therefore, the applied focus offsets 620a and 620b may result in an average value 625 of the two focus offsets 620a and 620b being the same as a single setting 615a and 615b or nominal focus used outside the stitching area 610.

[0092] Thus, the proposed method can include two exposures of the splicing area (i.e., the photoresist there), each at a different focal level. This is similar to focused drilling, in which multiple exposures can be performed on a common area of ​​the substrate at their respective focal levels.

[0093] Note that, optionally, the pattern within each mask stitching area can be optimized for focus offset so that CD is acceptable when exposed at the offset focus. This can be achieved using standard optical proximity correction (OPC) methods.

[0094] The figure also shows depth-of-focus or focus windows 630a and 630b corresponding to the exposure of the first sub-region 600 and the second sub-region 605 outside the stitching area, and a depth-of-focus or focus window 630c corresponding to the exposure of the stitching area 610. The depth-of-focus or focus windows 630a, 630b, and 630c define a focus range for which exposure performance (e.g., according to one or more performance parameters such as the critical size CD) is acceptable.

[0095] It can be seen that the applied relative focus offsets 620a and 620b result in an increased depth of focus 630c for the stitching area compared to 630a and 630b. A greater depth of focus allows for greater tolerance to leveling and other focusing errors. Due to the greater tolerance for the initial exposure settings, the impact of overlapping exposures on throughput can be partially compensated. This allows for different optimal values ​​to be set for optical proximity correction (OPC) and illumination settings (e.g., using a MEMS illuminator) within the stitching area.

[0096] Alternatively, in addition to the applied relative focus offsets 620a, 620b, the entire dose can be distributed across the two exposures within the stitching area, for example, so that each exposure receives a portion (e.g., half) of the nominal target dose used for exposures outside the stitching area. Because the stitching area is exposed with a lower dose per image, the mask / mirror / wafer heating effect in the overlapping area is reduced, thus achieving better patterning performance.

[0097] More generally, it is proposed to allocate corrections between two exposures within the stitching area, for example, to synergistically optimize complementary corrections applied within the stitching area. A complementary correction combination can be determined, comprising a first correction distribution for the exposure of the first sub-region 700 and a second correction distribution for the exposure of the second sub-region 705, to improve and / or optimize patterning within the stitching area through the combined effect of the complementary corrections. Such correction distributions can be determined for any exposure setting, such as dosage, focus, or planar position (e.g., stitching overlay and / or regular overlay).

[0098] Figure 7 This method of dose correction distribution is illustrated. A first dose correction distribution 720a and a corresponding second dose correction distribution 720b are shown, applied during exposure of a first sub-region 700 and a second sub-region 705 within the splicing region 710. In an embodiment, each sub-region may be exposed using a different mask; the first sub-region 700 is exposed using mask ARET A, and the second sub-region 705 is exposed using mask BRET B (although the same mask may be used for both sub-regions).

[0099] The applied dose distributions 720a and 720b can be: a total dose distribution 725 that is the same as the individual setpoints 715a and 715b or nominal doses used to expose sub-regions 700 and 705 outside the stitching area 710. Advantageously, both dose distributions from masks A and B within the stitching area are taken into account, thereby reducing discontinuities between sub-regions 700 and 705.

[0100] In an embodiment, the combination of the first dose correction distribution 720a and the second dose correction distribution 720b in the stitching region 710 can be configured such that their combined effect optimizes the patterning. Differences in interference between exposures can be averaged. This is in principle similar to using a “voting” strategy, such as that used to mitigate mask defects. A “voting” strategy adds N different mask images with the same content, each image being a 1 / N dose, to mitigate defects on each individual mask. The assumption is that mask defects are positionally independent from one mask to another, so each individual defect is blended with good images from the other N-1 masks.

[0101] Optimization can take the form of minimizing, for example, exposure performance metrics such as critical size uniformity (CDU) and the combined effect of the first dose distribution 720a and the second dose distribution 720b. Thus, the inter-field dose correction distribution can be allocated between the exposures of the first sub-region 700 and the second sub-region 705 to achieve a minimum CD deviation (CDU) from the target CD. in, and These are the dose values ​​of the first sub-region 700 and the second sub-region 705 during exposure (within the stitching area 710), respectively, where y is the scanning direction. and These are adjustable CD sensitivities for the dose applied to the first sub-region 700 and the second sub-region 705, respectively, assuming that CD is a linear function of the dose (i.e., More generally, optimization or minimization can be simply expressed as co-optimizing the dosage. , To minimize CDU (or other performance metrics as a function of dose); that is:

[0102] The final CD curve along the scanning direction y is shown, including: a first CD track 730a, corresponding to the exposure of the first sub-region 700 outside the stitching area 710; a second CD track 730b, corresponding to the exposure of the second sub-region 705 outside the stitching area 710; and a third CD track 730c, corresponding to the exposure of sub-regions 700 and 705 within the stitching area 710. It can be seen that the CD value 730c within the stitching area is smaller than the CD values ​​730a and 735b outside the stitching area.

[0103] Different overlay corrections for exposures in the first sub-region 700 and the second sub-region 705 will widen the CD. This can be partially compensated for by dosage or by the difference in overlay correction between two exposures within the simultaneous stitching area. Similarly, different focus corrections for exposures in the first sub-region 700 and the second sub-region 705 will widen the CD. This can be partially compensated for by dosage or by the difference in focus correction between two exposures within the simultaneous stitching area.

[0104] In the embodiments, some or all of the dose corrections are applied during the exposure of the first sub-region 700 and the second sub-region 705, respectively. , In-plane position correction , , , (For example, for stitching overlay, describing the relative alignment and / or conventional overlay correction of the first sub-region 700 and the second sub-region 705), and focus correction. , It can be jointly optimized within the stitching area to minimize or optimize exposure performance metrics such as edge position error (EPE).

[0105] Since both exposures can be used for correction, and the interference is averaged between the two exposures, the EPE between exposures should be expected to be reduced.

[0106] Figure 8 Another embodiment is described, which allows splice overlay to be measured directly on the device pattern (product structure) without the need for dedicated splice overlay targets (structures in each of the first sub-region 800 and the second sub-region 805 within the splice area 810). Such splice overlay targets are relatively large and occupy space that cannot therefore be used for device structures (functional structures). In this embodiment, each sub-region uses a different mask; for example, the first sub-region 800 is exposed using mask A RET A, and the second sub-region 805 is exposed using mask B RET B (although the same mask can be used for both sub-regions). When this occurs, it is difficult to determine which mask is the displacement contributor within the splice area for each sub-region.

[0107] The diagram shows the first overlay dX, dY curves 815a corresponding to the exposure of the first sub-region 800, and the second overlay dX, dY curves 815b corresponding to the exposure of the second sub-region 805 (each curve shows the overlay along the scanning direction y). It can be seen that there is a mismatch between curves 815a and 815b, which is indicative of overlay error. Corresponding CD curves are also shown, including the first CD curve 820a corresponding to the exposure of the first sub-region 800 outside the stitching area 810, the second CD trajectory 820b corresponding to the exposure of the second sub-region 805 outside the stitching area 810, and the third CD trajectory 820c corresponding to the exposure of the sub-regions 800 and 805 within the stitching area 810.

[0108] It can be seen that the CD of the third CD trajectory 820c is significantly larger than that of the first and second CD trajectories 820a and 820b. This is due to the stitching overlay error or relative position difference between the first sub-region 800 and the second sub-region 805. The reason is that the image formed in the stitching area 810 includes a composite image formed by the first and second images overlapping in their respective sub-regions 800 and 805. If the first image deviates (slightly) from the second image, the CD of the composite image (and therefore the local CDU, LCDU) will increase effectively. A graph 825 showing the CD or LCDU relative to the stitching overlay dx and dy is shown. It can be seen that there is a minimum CD or LCDU at the zero stitching overlay, and the CD / LCDU increases with the increase of the stitching overlay dx and dy.

[0109] This paper proposes to utilize this displacement to calculate the overlay introduced in the stitching region. Advantageously, the relative displacement between the exposure of mask A and the exposure of mask B in stitching region 810 can be determined. Alternatively, in addition to enabling better control over the position of each region 800, 805 relative to each other, this relative displacement can be used to improve overlay control relative to one or more other layers.

[0110] An example of a composite image is shown. A first composite image 830 is shown, which is formed within a stitching region 810 by a first image 830a and a second image 830b, while a second composite image 830' is formed within the stitching region 810 by a first image 830a' and a second image 830b'. In each case, the first images 830a and 830a' are exposed during the exposure of the first sub-region 800, and the second images 830b and 830b' are exposed during the exposure of the second sub-region 805. The first composite image 830 is the image that can be seen only when there is a stitching overlay error in the y-direction, while the second composite image 830' is the image that can be seen only when there is a stitching overlay error in the x-direction. Of course, in practical examples, stitching overlay errors can exist in both in-plane directions.

[0111] Therefore, it is proposed that CD and / or LCDU (i.e., critical size parameters) are measured from the structure and used to determine the stitching overlay. The measured structure may contain functional product structures rather than dedicated stitching targets, although small, simple CD stitching targets can be used instead. The method may include calibrating the relationship between stitching overlay and CD and / or LCDU, and using this calibrated relationship to infer the stitching overlay. Such calibration may include exposing multiple stitching fields with different known stitching target offsets and measuring the final CD and / or LCDU of the composite structure. For example, a calibration model may be fitted to a graph of the measured CD and / or LCDU relative to the stitching overlay, or a machine learning model may be trained to map CD and / or LCDU to the stitching overlay.

[0112] The following numbered clauses describe various aspects and / or embodiments of the invention: 1. A method for determining correction for controlling at least one manufacturing apparatus used in a manufacturing process for providing a structure for at least one region on a substrate, said region comprising at least a first sub-region and a second sub-region in a common layer; the method comprising: Process error data related to the manufacturing process is acquired when the first sub-region is formed on the substrate; A first product error is determined based on the process error data, and the product error is related to the error in the formation of the first sub-region; and When the second sub-region is formed on the substrate, a correction to the manufacturing process is determined based on the product error. 2. The method according to Clause 1, wherein the correction is determined to reduce or minimize any difference between the product error of the first sub-region and the product error of the second sub-region. 3. The method according to Clause 1 or 2, wherein the error on the product is at least partially related to the position of the structure relative to the first sub-region; and The correction reduces or minimizes the splicing overlay error, which describes the relative positioning error between the first sub-region and the second sub-region. 4. The method according to any of the preceding clauses, wherein the error on the product is at least partially related to the overlay error of the first sub-region relative to the previous layer; and The correction reduces or minimizes the overlay error of the second sub-region relative to the previous layer. 5. The method according to any of the preceding clauses, wherein the product error is related to the structure's position relative to the first sub-region and the overlay error of the first sub-region relative to the previous layer; and The correction and co-optimization describes the splicing and overlay error of the relative positioning error between the first sub-region and the second sub-region, as well as the overlay error of the second sub-region relative to the previous layer. 6. The method according to any of the preceding clauses, wherein the correction includes feedforward correction of the exposure of the second sub-region on the same substrate as the first sub-region exposed, to obtain the process error data. 7. The method according to any of the preceding clauses, wherein the process error data includes error data generated in the manufacturing process and / or error data generated within the manufacturing apparatus when forming the first sub-region. 8. The process error data according to any of the preceding clauses includes one or more of the following: lens model error data, lens fingerprint data, actuation error data, lens overpressure error data, alignment data and / or alignment residual data. 9. The method described according to any of the preceding clauses, wherein the manufacturing process is a photolithography and / or exposure process, and the manufacturing apparatus is a photolithography and / or exposure apparatus. 10. The method according to any of the preceding clauses, wherein the step of determining correction includes determining the corrective action according to one or more rules and / or constraints. 11. As described in Clause 10, one or more rules and / or constraints include possible and / or permissible actuation, preferred actuation, prohibited actuation, permissible errors in sub-region deformation, permissible overlay errors, and / or splicing overlay errors. 12. The method according to any of the preceding clauses, wherein the correction is determined as an additional term for an evaluation function used to determine the actuation trajectory forming the second sub-region, the additional term including the difference between the actuation residual associated with the formation of the second sub-region and the actuation residual associated with the formation of the first sub-region. 13. The method according to any of the preceding clauses, wherein the first sub-region is formed multiple times on the substrate in the first exposure sequence, and the second sub-region is formed multiple times on the substrate in the second exposure sequence. 14. The method according to Clause 13, the method comprising determining a second exposure sequence to ensure sufficient computation time is available for determining and correcting errors on the product. 15. The method described in Clause 14, sufficient computation time includes ensuring that sufficient computation time is provided to maintain a substantially stable queue depth for queuing formation of the second sub-region. 16. The method according to clauses 13, 14 or 15 further includes forwarding measured alignment data and / or modeled alignment data associated with the first exposure sequence for use when performing the second exposure sequence. 17. The method according to Clause 16 further includes configuring the optical device in a first configuration for a first exposure sequence and a second configuration for a second exposure sequence. 18. The method according to Clause 17, wherein the first configuration and the second configuration are based on alignment mark type, color formula, alignment mark sampling strategy and alignment model. 19. The method according to Clause 13, 14 or 15 further includes forwarding measured leveling data and / or modeled leveling data associated with the first exposure sequence for use when performing the second exposure sequence. 20. The method according to any of the preceding clauses, wherein the manufacturing process provides the structure on the substrate in multiple exposures, each exposure defining a corresponding one of the sub-regions, the sub-regions being exposed substantially adjacently to define the region. 21. The method according to Clause 20, wherein substantially adjacent exposures include small overlapping areas. 22. The method according to clause 20 or 21, wherein the region has a region larger than the maximum scanning field area of ​​the manufacturing apparatus. 23. The method according to Clause 22, wherein each sub-region has a zone defined by the maximum field area of ​​the manufacturing apparatus. 24. The method according to any of the preceding clauses, wherein the first sub-region and the second sub-region include a common splicing area defined by the overlapping area of ​​the first sub-region and the second sub-region; and the method includes: Within the stitching area, the first sub-region and the second sub-region are exposed with corresponding complementary focus and / or dose settings. 25. The method according to Clause 24, wherein the respective complementary focus comprises: applying a focus offset of equal magnitude in a relative direction when exposing the first sub-region and the second sub-region, respectively, relative to the nominal focus. 26. The method according to Clause 24 or 25, wherein the respective complementary doses include distributing a nominal dose between the exposure of the first sub-region and the second sub-region, such that the combined dose of the exposure of the first sub-region and the second sub-region includes the nominal dose. 27. The method according to any of the preceding clauses, wherein the first sub-region and the second sub-region include a common splicing area defined by the overlapping area of ​​the first sub-region and the second sub-region; and the method includes: Within the stitching area, the first sub-region and the second sub-region are exposed with corresponding complementary corrections set for one or more exposures. 28. The method according to Clause 27, wherein the one or more exposure settings include one or more of dose, focus, and / or in-plane positioning. 29. The corresponding complementary corrections are synergistically optimized in accordance with the method described in Clause 27 or 28 in order to improve and / or optimize exposure performance metrics within the stitching area. 30. The method according to Clause 29, wherein the exposure performance metric includes critical size uniformity or edge placement error. 31. The method according to any of the preceding clauses, wherein the first sub-region and the second sub-region include a common splicing area defined by the overlapping area of ​​the first sub-region and the second sub-region; and the method includes: Measuring critical size parameters of a composite image formed by exposing a first image within the stitching area of ​​the first sub-region and an overlapping second image within the stitching area of ​​the second sub-region; and Based on the critical size parameters, the splicing and overlay between the first sub-region and the second sub-region is determined. 32. The method according to Clause 31, wherein determining the stitching overlay includes using a pre-calibration relation and / or model for mapping the critical dimension parameters to the stitching overlay to determine the stitching overlay. 33. The method according to clause 31 or 32, wherein the measured composite image includes a functional product structure. 34. The method according to any of the preceding clauses, wherein the step of determining correction includes applying a splicing region performance penalty and / or constraint that imposes a constraint on the splicing overlay error between the first sub-region and the second sub-region. 35. The method according to Clause 34, wherein within the splicing region defined by the overlap of the first sub-region and the second sub-region, the splicing region performance penalty constraint and / or penalty for differences in residual values ​​of one or more of the following, individually or in any combination: focus, dose, overlay, or splicing overlay. 36. The method according to Clause 35, wherein the splicing region performance penalty includes a splicing dead zone threshold, the threshold defining a minimum correlation difference in the residual values ​​below which the residual values ​​are considered negligible. 37. The method described in accordance with Clauses 34, 35 or 36, including the effect of adjusting the performance penalty of the splicing region by means of splicing hyperparameters. 38. The method according to any of the preceding clauses, wherein the step of determining correction includes applying a through-stack penalty and / or constraint that imposes a constraint and / or penalty on the overlay error relative to at least one subsequent layer exposed after the common layer. 39. The method according to Clause 38, wherein the through-stack penalty constraint is corrected in the common layer to enable the first layer exposure to be acceptablely performed in the subsequent layers, wherein the common layer and the first layer are exposed using different lithography apparatuses with different correction capabilities and / or different field sizes. 40. The method according to Clause 39, wherein the through-stack penalty includes a through-stack dead zone threshold, which is limited to the minimum relevant difference in the through-stack residual value. 41. The method according to clauses 38, 39 or 40, including adjusting the effect of the through-stack penalty via through-stack hyperparameters. 42. The method according to any of the preceding clauses includes performing the manufacturing process to form the first sub-region and the second sub-region, such that the second sub-region is formed according to the correction. 43. A method for determining correction for controlling at least one manufacturing apparatus used in a manufacturing process for providing a structure for at least one region on a substrate, said region comprising at least a first sub-region and a second sub-region in a common layer, wherein the first sub-region and the second sub-region comprise a common splice area defined by an overlap region of the first sub-region and the second sub-region; the method comprising: Process error data related to the manufacturing process is acquired when the first sub-region and the second sub-region are formed on the substrate; Based on process error data, determine a co-optimization correction for each of the at least first and second sub-regions, wherein determining the co-optimization correction includes applying at least one of the following: Performance penalties and / or constraints on the splicing region, which impose penalties and / or constraints on at least one parameter of interest within the splicing region; and / or Penalties and / or constraints are applied throughout the stacking process, which impose penalties and / or constraints on overlay errors relative to at least one subsequent layer exposed after the common layer. 44. The method according to Clause 43, wherein the at least one parameter of concern comprises one or more of the following, alone or in any combination: focus, dosage, overlay or splicing overlay. 45. The method according to Clause 43 or 44, wherein the splicing region performance penalty and / or constraint restricts and / or penalizes the residual value difference of the parameters of concern within the splicing region. 46. ​​The method according to Clause 45, wherein the splicing region performance penalty and / or constraint includes a splicing dead zone threshold, the threshold defining a minimum relevant difference in the residual value, the residual value below which is considered insignificant. 47. The method according to any one of clauses 41 to 46, wherein the through-stack penalty and / or constraint penalty and / or constraint is to be applied in the common layer to enable the first layer exposure to be acceptablely performed in the subsequent layers, wherein the common layer and the first layer are exposed using different lithography apparatuses with different correction capabilities and / or different field sizes. 48. The method according to Clause 47, wherein the stack penetration penalty includes a stack penetration dead zone threshold, the threshold defining a minimum correlation difference in the stack penetration residual value. 49. The method according to any one of Clauses 41 to 48, including adjusting the effect of one or both of the splicing region performance penalty and / or constraint and / or the through-stack penalty and / or constraint by respective hyperparameters. 50. A process apparatus for determining corrections to the control of at least one manufacturing apparatus configured to provide a product structure for a substrate in a manufacturing process, the process apparatus being configured to perform the method of any one of clauses 1 to 49. 51. A manufacturing apparatus configured to provide a product structure to a substrate in a manufacturing process, said manufacturing apparatus comprising process equipment according to clause 50. 52. The manufacturing apparatus according to clause 51, wherein the manufacturing apparatus includes a photolithography apparatus, the photolithography apparatus having: Substrate stage, used to hold the substrate; A mask stage is used to hold patterning equipment. The processor is capable of operating to use the correction control manufacturing process. 53. A computer program comprising program instructions that, when run on a suitable device, are operable to perform the method of any one of clauses 1 to 49. 54. A non-transitory computer program carrier, comprising the computer program described in clause 53. 55. A method for manufacturing a semiconductor device using a manufacturing process, said manufacturing process comprising, Receive a substrate with a photoresist layer. The manufacturing process correction is determined according to any one of clauses 1 to 49, and the radiation beam is controlled according to the determined correction, wherein the radiation beam is emitted from a radiation source to transfer a pattern from a mask onto a photoresist layer. A portion of the photoresist layer is removed to form the pattern on the substrate.

[0113] Although the above description describes corrections for lithography apparatus / scanners, the determined corrections can also be used in any process and can be used by any integrated circuit (IC) manufacturing apparatus in an integrated circuit (IC) manufacturing process, such as an etching apparatus that has an effect on the position and / or size of structures formed within a layer.

[0114] The terms “radiation” and “beam” used in relation to lithography apparatus cover all types of electromagnetic radiation, including ultraviolet (UV) radiation (e.g., wavelengths of 365, 355, 248, 193, 157, or 126 nm or approximately those values) and extreme ultraviolet (EUV) radiation (e.g., wavelengths in the range of 5–20 nm), as well as particle beams, such as ion beams or electron beams.

[0115] The term "lens," when the context allows, can refer to any one or combination of various types of optical components, including refractive, reflective, catadioptric, magnetic, electromagnetic, and electrostatic optical components.

[0116] The foregoing description of specific embodiments so fully reveals the general nature of the invention that others, by employing knowledge of the art, can readily modify and / or adapt such specific aspects to suit a variety of applications without undue experimentation and without departing from the general conception of the invention. Therefore, based on the teachings and guidance herein, such modifications and adaptations are intended to fall within the meaning and scope of equivalents to the embodiments of this disclosure. It should be understood that the wording or terminology used herein is for the purpose of description by way of example and not for the purpose of limitation.

[0117] The breadth and scope of this invention should not be limited by any of the exemplary embodiments described above, but should be defined only by the following claims and their equivalents.

Claims

1. A method for determining corrections to the control of at least one manufacturing apparatus used in a manufacturing process for providing a structure for at least one region on a substrate, the region comprising at least a first sub-region and a second sub-region in a common layer; the method comprising: When the first sub-region is formed on the substrate, process error data related to the manufacturing process is acquired; The first product error is determined from the process error data, and the product error is related to the error in the formation of the first sub-region; as well as When the second sub-region is formed on the substrate, the error on the product is used to determine the correction of the manufacturing process.

2. The method of claim 1, wherein the correction is determined to reduce or minimize any difference between the product error of the first sub-region and the product error of the second sub-region.

3. The method according to claim 1 or 2, The product error is at least partially related to the position of the structure relative to the first sub-region; and The correction reduces or minimizes the splicing overprinting error, which describes the relative positioning error between the first sub-region and the second sub-region.

4. The method according to any one of the preceding claims, wherein the error on the product is at least partially related to the overlay error of the first sub-region relative to the previous layer; and The correction reduces or minimizes the overprinting error of the second sub-region relative to the previous layer, and / or wherein the error on the product is related to the structure's position relative to the first sub-region and the overprinting error of the first sub-region relative to the previous layer; and The correction and collaborative optimization includes: splicing overlay error, which describes the relative positioning error between the first sub-region and the second sub-region; and the overlay error of the second sub-region relative to the previous layer.

5. The method according to any one of the preceding claims, wherein the correction includes feedforward correction of the exposure of the second sub-region on the same substrate as the first sub-region being exposed, to obtain the process error data.

6. The method according to any one of the preceding claims, wherein the correction is determined as: an additional term for determining the evaluation function of the actuation trajectory forming the second sub-region, the additional term comprising: The difference between the actuation residues associated with the formation of the second sub-region and the actuation residues associated with the formation of the first sub-region.

7. The method according to any one of the preceding claims, wherein the first sub-region is formed multiple times on the substrate in a first exposure sequence, and the second sub-region is formed multiple times on the substrate in a second exposure sequence, wherein the method further comprises: Forward the measured alignment data and / or modeled alignment data associated with the first exposure sequence for use when executing the second exposure sequence.

8. The method according to any one of the preceding claims, wherein the first sub-region and the second sub-region include a common splicing area, the common splicing area being defined by the overlap area of ​​the first sub-region and the second sub-region; and the method comprising: Within the stitching area, the first sub-region and the second sub-region are exposed with corresponding complementary focus and / or dose settings.

9. The method according to any one of the preceding claims, wherein the first sub-region and the second sub-region include a common splicing area, the common splicing area being defined by the overlap area of ​​the first sub-region and the second sub-region; and the method comprising: Within the stitching area, the first sub-region and the second sub-region are exposed with corresponding complementary corrections set for one or more exposures.

10. The method of claim 9, comprising: The corresponding complementary corrections are synergistically optimized in terms of improving and / or optimizing exposure performance metrics within the stitching area.

11. The method according to any one of the preceding claims, wherein the first sub-region and the second sub-region include a common splicing area, the common splicing area being defined by the overlap area of ​​the first sub-region and the second sub-region; and the method comprising: Measuring critical size parameters of a composite image, the composite image being formed by a first image exposed within a stitching area of ​​a first sub-region and an overlapping second image exposed within a stitching area of ​​a second sub-region; and The splicing and overlay between the first sub-region and the second sub-region is determined from the critical size parameters.

12. The method according to any one of the preceding claims, wherein the step of determining the correction comprises: A splicing area performance penalty and / or constraint is applied, which imposes a constraint on the splicing overlay error between the first sub-region and the second sub-region.

13. The method of claim 12, wherein within the splicing region defined by the overlap of the first sub-region and the second sub-region, the splicing region performance penalty constraint and / or penalty for the differences in residual values ​​of one or more of the following, individually or in any combination: focus, dose, overlay, or splicing overlay.

14. The method according to any one of the preceding claims, wherein the step of determining the correction comprises: Apply through-stack penalties and / or constraints that impose constraints and / or penalties on overlay errors relative to at least one subsequent layer exposed after the common layer.

15. A computer program comprising program instructions that, when run on a suitable device, are operable to perform the method of any one of claims 1 to 14.

16. A method for manufacturing a semiconductor device using a manufacturing process, the manufacturing process comprising, Receiving substrate, the substrate having a photoresist layer, According to any one of claims 1 to 14, a correction to the manufacturing process is determined. According to the determined calibration control radiation beam, wherein the radiation beam is guided from the radiation source to transfer the pattern from the mask onto the photoresist layer, A portion of the photoresist layer is removed to form the pattern on the substrate.

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