Digital lithography exposure unit border smoothing

Abstract

A system comprising a memory and at least one processing device operatively coupled to the memory to perform operations comprising initiating a digital lithography process to pattern a substrate using a digital lithography system, controlling an area ratio in a first direction with respect to a first pair of adjacent exposure cells of the digital lithography system, and controlling a dose ratio in a second direction perpendicular to the first direction with respect to a second pair of adjacent exposure cells of the digital lithography system.

Description

Technical Field

[0001] This manual generally relates to the manufacture of electronic devices. More specifically, this manual relates to digital lithography. Background Technology

[0002] Photolithography is used to manufacture semiconductor devices and display devices, such as flat panel displays. Typically, a flat panel display includes a layer of liquid crystal material sandwiched between two plates, serving as the phase-change material at each pixel. Examples of flat panel display devices include thin-film display devices, such as liquid crystal displays (LCDs) and organic light-emitting diode (OLED) displays. Flat panel display devices can be used, for example, in computers, touch panel devices, personal digital assistants (PDAs), cellular phones, television monitors, and the like. When power from a power supply is applied to or via the liquid crystal material, the amount of light passing through the liquid crystal material is controlled (e.g., selectively modulated) at the pixel location so that an image can be generated on the display. In some cases, large-area substrates can be used to manufacture flat panel display devices. Summary of the Invention

[0003] The following is a simplified overview of this disclosure to provide a basic understanding of some aspects thereof. This disclosure is not a comprehensive summary of the present invention. It is not intended to identify key or essential elements of the disclosure, nor is it intended to define any scope of any particular implementation of the disclosure or any of the claims. Its sole purpose is to present some concepts of the disclosure in a simplified form as a prelude to the more detailed description that follows.

[0004] According to an embodiment, a system is provided. The system includes a memory and at least one processing means operatively coupled to the memory to perform operations including initiating a digital lithography process to pattern a substrate using a digital lithography system, controlling the area ratio of a first pair of adjacent exposure units relative to the digital lithography system in a first direction, and controlling the dose ratio of a second pair of adjacent exposure units relative to the digital lithography system in a second direction perpendicular to the first direction.

[0005] According to another embodiment, a method is provided. The method includes initiating a digital lithography process by at least one processing device to pattern a substrate using a digital lithography system, the at least one processing device controlling the area ratio of a first pair of adjacent exposure units relative to the digital lithography system in a first direction, and the at least one processing device controlling the dose ratio of a second pair of adjacent exposure units relative to the digital lithography system in a second direction perpendicular to the first direction.

[0006] According to another embodiment, a system is provided. The system includes: a stage associated with a plurality of scanning areas; a plurality of exposure units located above the stage, the plurality of exposure units including a first pair of adjacent exposure units and a second pair of adjacent exposure units; and at least one processing means operatively coupled to a memory to perform operations including initiating a digital lithography process to pattern a substrate disposed on the stage, controlling an area ratio relative to the first pair of adjacent exposure units in a first direction, and controlling a dose ratio relative to the second pair of adjacent exposure units in a second direction perpendicular to the first direction. Attached Figure Description

[0007] The aspects and implementations of this disclosure will be more fully understood from the detailed description given below and from the accompanying drawings, which are intended to illustrate aspects and implementations as examples rather than limitations.

[0008] Figure 1 This is a schematic partial perspective view of a digital lithography system according to some embodiments.

[0009] Figure 2 A block diagram of a digital lithography system according to some embodiments.

[0010] Figure 3 This is an illustration of a digital lithography system according to some embodiments.

[0011] Figure 4 This is a top view of a digital lithography system according to some embodiments.

[0012] Figures 5A to 5D The top view, according to some embodiments, shows the scanning path of a substrate through a single digital lithography exposure unit of a digital lithography system.

[0013] Figure 6 An illustration of exposure unit boundary smoothing performed by a digital lithography system, from a top-down perspective, according to some embodiments.

[0014] Figure 7This is a flowchart of a method for achieving smoothing of the exposure unit boundaries in digital lithography, according to some embodiments.

[0015] Figure 8 A block diagram illustrating a computer system according to certain embodiments. Detailed Implementation

[0016] Digital lithography (also known as maskless or direct-write lithography) is a process that uses a digital pattern file to induce electromagnetic radiation (such as lasers, ultraviolet light, UV, near-UV, etc.) to expose photoresist, thereby creating patterns on a substrate without the need for a photomask. Examples of digital lithography include maskless lithography and direct-write lithography. Digital lithography technology provides a high-speed, high-resolution maskless lithography solution for printed circuit board (PCB) patterning, solder masking, flat panel displays, laser marking, and other digital exposure systems that benefit from high speed and precision. Digital lithography can be used to directly expose patterns onto a photoresist film without the use of a contact mask (e.g., a photomask). This reduces material waste, increases production rates, and allows for rapid pattern changes. Direct exposure increases productivity compared to narrow laser beams or masked systems. A key advantage of digital lithography is its ability to change the lithographic pattern from one run to the next without incurring the cost of creating a new photomask. For example, digital lithography can be used to perform large-area patterning during the manufacturing of electronic devices.

[0017] Digital lithography systems may include multiple image projection systems or digital lithography exposure units (“exposure units”), also referred to herein as EYEs. A group of exposure units may be attached to corresponding bridging elements, and a digital lithography system may include one or more bridging elements. Some digital lithography systems can perform splicing to manufacture flat panel display devices from large-area substrates. During splicing, each exposure unit may be responsible for a portion of the printing area to increase throughput. For example, some exposure units may print or expose rectangular non-overlapping areas, or cut layers. Each of the multiple exposure units may be responsible for a portion of the printing area and a different cut layer. The cut layer may act as a filter to instruct the layout processing software to maintain the pattern to be printed by a particular exposure unit on the cut layer associated with that exposure unit. More specifically, each exposure unit may expose a corresponding scanned area of ​​the substrate to a certain amount of energy, referred to herein as a “dose.” For example, the dose may correspond to a certain number of photons emitted by the exposure unit and incident on the scanned area.

[0018] However, exposure units may possess unique characteristics that prevent them from being accurately matched with other exposure units. This mismatch can lead to inhomogeneities (e.g., unevenness, inconsistency, irregularity) and visible defects during splicing, also known as "moogloss." Moogloss, a term originating in Japan, generally refers to any visible defect, such as visible variations, that is present on a display device due to scanning processes (e.g., splicing). In some cases, moogloss may include visible boundaries between areas printed by pairs of adjacent exposure units. The presence of moogloss can present a display device defect for its intended purpose. For example, these defects can be visually observed and may affect display quality. Therefore, reducing moogloss can improve display device manufacturing throughput and display device quality.

[0019] The aspects and implementations of this disclosure address these and other drawbacks of the prior art by performing exposure cell boundary smoothing to reduce inhomogeneities within the areas scanned by adjacent exposure cells. Mixing can create a more gradual transition between boundaries, reducing the appearance of visible irregularities perceptible to the human eye. Therefore, the embodiments described herein can be used to improve the quality and throughput of display devices.

[0020] Exposure unit boundary smoothing can be performed to smooth eye-to-eye (E2E) boundaries and bridging-to-bridging (B2B) boundaries in multiple directions. E2E boundaries refer to the boundaries separating adjacent scan regions, each defined for a corresponding exposure unit in a pair of exposure units attached to the same bridging element (e.g., a first exposure unit and a second exposure unit each attached to the same bridging element). B2B boundaries refer to the boundaries separating adjacent scan regions, each defined for a corresponding exposure unit in a pair of exposure units attached to different bridging elements (e.g., a first exposure unit attached to a first bridging element, and a second exposure unit attached to a second bridging element adjacent to the first bridging element).

[0021] More specifically, performing exposure unit boundary smoothing may include performing a combination of jitter and dose mixing to reduce the occurrence of moiré patterns. For example, reducing the occurrence of moiré patterns may include reducing the occurrence of eye-to-eye perceptible E2E boundaries and / or B2B boundaries.

[0022] For each of a pair of adjacent exposure units, jitter involves controlling which portions (“sub-regions”) of a scan area are scanned by the exposure unit. More specifically, an individual exposure unit in the pair will provide a target dose to a particular sub-region. The target dose of an exposure unit can be defined as the corresponding amount of dose (e.g., the amount of energy or the number of photons) provided by the exposure unit relative to the total possible dose (“total dose”).

[0023] For a pair of adjacent exposure units, dose mixing involves controlling the target dose delivered by each exposure unit within the scanned area. The target dose of an exposure unit can be defined as the corresponding amount of dose delivered by the exposure unit relative to the total dose (e.g., the amount of energy or the number of photons). For example, the first exposure unit in the pair can be controlled to deliver a dose of X% of the total dose within the scanned area, and the second exposure unit in the pair can be controlled to deliver a dose of Y% of the total dose within the scanned area, where the sum of X and Y is 1 (e.g., 100% of the total dose). The percentage of total dose delivered by the first and second exposure units can be selectively controlled depending on where the scanned area is located.

[0024] More specifically, performing the combination of jitter and dose mixing may include controlling jitter in a first direction. In some embodiments, the first direction is a scanning direction. For example, the scanning direction may be horizontal, as viewed from a top-down perspective (e.g., from left to right) of a digital lithography system. Jitter may be controlled for a first pair of adjacent exposure units, including a first exposure unit attached to a first bridging member and a second exposure unit attached to a second bridging member adjacent to the first bridging member, wherein a nominal B2B boundary separates a first scan area defined for the first exposure unit from a second scan area defined for the second exposure unit. More specifically, one of the first or second exposure units may be selected to provide its target dose based on the position of the exposure unit relative to the underlying substrate along the scanning direction. For example, the first exposure unit may be assigned to provide its target dose in a first sub-region, the second exposure unit may be assigned to provide its target dose in a second sub-region, and both the first and second exposure units may be assigned to provide their target dose in a third sub-region having a total area. The third sub-region may be referred to as a B2B mixing region. More specifically, the B2B blending region can be divided into multiple sub-regions, each of which is formed by a corresponding portion of the total area of ​​the B2B blending region. Each sub-region of the B2B blending region may have an associated area ratio that defines the amount of area assigned to the first exposure unit for scanning and the amount of area assigned to the second exposure unit for scanning within the sub-region.

[0025] Performing the combination of jitter and dose mixing can further include controlling dose mixing in a second direction perpendicular to the first direction (e.g., perpendicular to the scanning direction). For example, the second direction may be vertical, as viewed from a top-down perspective of a digital lithography system. Dose mixing can be controlled for a second pair of adjacent exposure units, including a third and fourth exposure unit attached to the same bridging element, wherein a nominal E2E boundary separates a third scan region defined for the third exposure unit from a fourth scan region defined for the fourth exposure unit. More specifically, the target dose assigned to each of the third and fourth exposure units is based on the position of that exposure unit relative to the underlying substrate in a direction perpendicular to the scanning direction.

[0026] The jitter performed in the first direction between the first pair of adjacent exposure units can interact with the dose mixing performed in the second direction between the second pair of adjacent exposure units. For example, the first exposure unit described above can also be a third exposure unit, such that the first pair of adjacent exposure units includes a first exposure unit and a second exposure unit, and the second pair of adjacent exposure units includes a first exposure unit and a fourth exposure unit. Therefore, the B2B boundary can separate the first and second exposure units, the E2E boundary can separate the first and fourth exposure units, and the target dose determined for the first exposure unit based on the dose ratio for dose mixing with respect to the second exposure unit is the target dose applied based on the area ratio for jitter with respect to the fourth exposure unit.

[0027] The aspects and implementations of this disclosure result in technical advantages over other methods. For example, as mentioned above, the embodiments described herein can reduce the occurrence of moiré patterns, such as visible boundaries caused by inhomogeneities between adjacent exposure units. Therefore, the embodiments described herein enable improved photolithography for substrate patterning.

[0028] Figure 1 This is a schematic partial perspective view of a digital lithography system (“System”) 100 according to some embodiments. System 100 may include a digital lithography subsystem (“Subsystem”) 101. Subsystem 101 may include a stage 114 and a processing unit 104. Stage 114 is supported by a pair of tracks 116. Substrate 120 is supported by stage 114. Stage 114 is operable to move along the pair of tracks 116. Stage 114 may be configured as follows: Figure 1The processing unit 104 moves along the track 116 in the x and y directions as defined in the diagram. The processing unit 104 is configured to expose photoresist in a digital lithography process using one or more image projection systems (IPS) 106. The IPS 106 is supported by supports 108 adjacent to (e.g., across) the pair of tracks 116. The supports 108 provide openings 112 for the pair of tracks 116 and the stage 114 to pass beneath the processing unit 104. The subsystem 101 may further include an encoder coupled to the stage.

[0029] The substrate 120 may be formed of any suitable material or combination of materials, such as glass, which serves as part of a flat panel display. In other embodiments that may be combined with other embodiments described herein, the substrate 120 may be made of other materials capable of serving as part of a flat panel display. The substrate 120 has a film layer to be patterned (e.g., etched by its pattern) formed thereon, and a photoresist layer formed on the film layer to be patterned, the photoresist layer being sensitive to electromagnetic radiation (e.g., UV). Positive photoresist includes portions of photoresist that, when exposed to radiation, are soluble in a photoresist developer coated onto the photoresist after a pattern has been written into the photoresist using electromagnetic radiation. Negative photoresist includes portions of photoresist that, when exposed to radiation, are insoluble in a photoresist developer coated onto the photoresist after a pattern has been written into the photoresist using electromagnetic radiation. The chemical composition of the photoresist determines whether the photoresist is positive or negative. Examples of photoresists include, but are not limited to, at least one of diazonaphthoquinone, phenolic resin, poly(methyl methacrylate), poly(methylglutarimide), and SU-8. After the photoresist is exposed to electromagnetic radiation, a photoresist is developed, leaving an exposed underlying film. Then, using a patterned photoresist, the underlying film is etched through an opening pattern in the photoresist to form part of the electronic circuitry system of the display panel.

[0030] System 100 may further include a lithography controller 122 and a controller 110 communicatively coupled to subsystem 101. For example, encoder 118 may provide lithography controller 122 with information about the position of stage 114. Lithography controller 122 is generally designed to facilitate control and automation of the processing techniques described herein. Lithography controller 122 may be coupled to or communicate with processing unit 104, stage 114, and encoder 118. Processing unit 104 and encoder 118 may provide lithography controller 122 with information about substrate processing and substrate alignment. For example, processing unit 104 may provide information to lithography controller 122 to alert lithography controller 122 that substrate processing is complete. Controller 110 may be operable to deliver one or more virtual mask files corresponding to an exposure pattern, or controller 110 may be additionally configured to perform the processes described herein. The lithography controller 122 facilitates the control and automation of the digital lithography process based on a virtual mask file provided by the virtual mask software application 102. The virtual mask file that the lithography controller 122 can read determines which tasks will be performed on the substrate. The virtual mask file corresponds to the exposure pattern that will be written into the photoresist using electromagnetic radiation.

[0031] Processing unit 104 may include a pattern generator configured to receive a virtual mask file from virtual mask software application 102. The virtual mask file may be provided to processing unit 104 via lithography controller 122. Processing unit 104 is configured to expose photoresist in a digital lithography process using one or more IPS 106. The one or more IPS 106 are operable to project a write beam of electromagnetic radiation onto substrate 120. The exposure pattern generated by processing unit 104 is projected through IPS 106 to expose the photoresist of substrate 120 to the exposure pattern. The exposure of the photoresist forms one or more different features in the photoresist. In one embodiment that may be combined with other embodiments described herein, each IPS 106 includes a spatial light modulator to modulate the incident light to produce a desired image. Each spatial light modulator includes a plurality of electrically addressable elements that can be individually controlled. Based on digital pattern file 204 (in Figure 2As shown in the diagram, each electrically addressable element can be in an "ON" or "OFF" position. When light reaches the spatial light modulator, the electrically addressable elements in the "ON" position project multiple write beams onto a projection lens (not shown). The projection lens then projects the write beams onto the substrate 120. Electrically addressable elements include, but are not limited to, digital micromirrors, liquid crystal displays (LCDs), liquid crystal over silicon (LCOS) devices, ferroelectric liquid crystal on silicon (FLCoS) devices, micro-shutters, micro-LEDs, VCSELs, liquid crystal displays (LCDs), or any solid-state electromagnetic radiation emitter.

[0032] Figure 2 This is a block diagram of a digital offset printing system (“System”) 200 according to some embodiments. As shown, System 200 may include the above-mentioned references. Figure 1 The described components include a subsystem 101, a virtual mask software application 102, and a controller 110. The controller 110 is operable to facilitate the transmission of a digital pattern file 204 (e.g., data) provided to the controller 110. The controller 110 is operable to execute the virtual mask software application 102 to convert the digital pattern file 204 into a virtual mask file (not shown) having an exposure pattern readable by the processing unit 104. Each of the lithographic printing environment devices is operable to connect to each other via a communication link. Each of the lithographic printing environment devices is operable to connect to the controller 110 via a communication link. The lithographic printing environment may be located in the same area or production facility, or each of the lithographic printing environment devices may be located in different areas.

[0033] The controller 110 includes a central processing unit (CPU) 212, support circuitry 214, and memory 216. The CPU 212 can be any type of computer processor used in an industrial environment for controlling lithographic environment devices. The memory 216 is coupled to the CPU 212. The memory 216 can be one or more readily available memories, such as random access memory (RAM), read-only memory (ROM), floppy disk, hard disk, or any other form of digital storage device (local or remote). The support circuitry 214 is coupled to the CPU 212 to support the processor. For example, the support circuitry 214 may include a cache, power supply, clock circuitry, input / output circuitry systems, subsystems, etc. The CPU 212 may be coupled to input / output (I / O) devices located in the support circuitry 214 and memory 216. The controller 110 is operable to facilitate and transmit digital pattern files 204 to the digital lithographic system 100 via a communication link. The digital pattern file 204 is operable to be provided to the virtual mask software application 102 or the digital lithography system 100 via the controller 110.

[0034] Memory 216 may include one or more software applications, such as virtual mask software application 102. CPU 212 may be a hardware unit or a combination of hardware units capable of executing software applications and processing data. In some configurations, CPU 212 includes a digital signal processor (DSP), an application-specific integrated circuit (ASIC), and / or a combination of these units. CPU 212 is configured to execute one or more software applications (such as virtual mask software application 102) and process stored media data, which may each be included in memory 216. Controller 110 controls the transfer of data and files to and from various lithography environment devices.

[0035] Controller 110 is operable to receive an exposure pattern from a virtual mask file and transmit the exposure pattern to the digital lithography system 100 via a communication link. The virtual mask file (or computer instructions), which controller 110 can read and may be called an imaging design file, determines which tasks can be performed on the substrate. Although virtual mask software application 102 is illustrated as being separate from controller 110 (e.g., in the cloud), it is contemplated that virtual mask software application 102 may be locally stored (e.g., in memory 216).

[0036] The virtual mask file corresponds to a pattern written into the photoresist using electron beams output from the digital lithography system 100. In one embodiment, which can be combined with other embodiments described herein, the pattern can be formed by one or more patterning devices. For example, the one or more patterning devices are configured to perform ion beam etching, reactive ion etching, electron beam etching, wet etching, nanoimprint lithography (NIL), and combinations thereof. The virtual mask file may be provided in different formats. For example, the virtual mask file may be in either GDS or OASIS format (among others). The virtual mask file includes information corresponding to features of the exposure pattern to be produced on a substrate (e.g., substrate 120). The virtual mask file may include regions of interest corresponding to one or more structural elements. The structural elements may be constructed as geometries (e.g., polygons).

[0037] The lithography model can be a physically based model. For example, the lithography model can use a scalar or vector imaging model. In some embodiments, the lithography model utilizes a matrix defined by optical properties and / or photoresist properties. For example, this matrix may include a transmission cross coefficient (TCC). In some embodiments, other numerical simulation techniques may be utilized, such as Resolution Enhancement Technology (RET), Optical Proximity Correction (OPC), and Source Mask Optimization (SMO). However, all such models and modeling techniques (whether known or developed hereafter) are contemplated within the scope of this disclosure. The lithography model can be constructed and defined based on optical properties (e.g., optical properties of the digital lithography system 100) and photoresist properties (e.g., properties of the photoresist on which patterns will be printed, such as the material and processing characteristics of the photoresist). Photoresist properties include numerical aperture, exposure, illumination type, illumination size, and wavelength, and may include other values.

[0038] Once the lithography model is constructed, a virtual mask file can be provided as input. The lithography model can then output an aerial image of the virtual mask file and a prediction of the resist profile. Through post-processing operations, the ILS and depth of focus based on the characteristics formed in the photoresist on the substrate based on the virtual mask file can be determined. The lithography model will use numerical computation to predict variables to achieve maximum ILS and depth of focus (or maximum ILS and depth of focus within other predefined constraints). Variables include the width and position of the exposure pattern and the pattern offset value. Numerical computation can be an iterative method, a level set method, or any other numerical method operable to solve the lithography model.

[0039] Controller 110 provides digital pattern file 204 to virtual mask software application 102. Virtual mask software application 102 is operable to receive digital pattern file 204 via a communication link. Virtual mask software application 102 may be vMASC software. In one embodiment that may be combined with other embodiments described herein, virtual mask software application 102 is a software program stored in memory 216 of controller 110. CPU 212 is configured to execute the software program. In another embodiment that may be combined with other embodiments described herein, virtual mask software application 102 may be a remote computer server that includes a controller and memory (e.g., a data storage device).

[0040] The digital pattern file 204 can be converted into one or more virtual mask files by the virtual mask software application 102. For example, a first virtual mask file may correspond to an exposure pattern, and a second virtual mask file may correspond to another exposure pattern. The virtual mask file is a digital representation of the design to be printed by the digital lithography system 100. The virtual mask file is provided to the digital lithography system 100 via a communication link. The virtual mask file is stored in the digital lithography system 100.

[0041] Figure 3 This is a diagram illustrating a system 300 comprising multiple IPS 301s according to some embodiments. Figure 3As shown, each IPS 301 can generate a write beam 302 on the surface 304 of the substrate 120. These write beams 302 correspond to multiple processing positions 312 and are generated along multiple tracks 116, each of which is scanned by one or more of the write beams 302. The substrate 120 moves in the in-scan direction indicated by arrow 315, while the cross-scan direction is indicated by arrow 320. As the substrate 120 moves in the in-scan direction and the cross-scan direction, the entire surface 304 can be patterned by the write beams 302. The number of IPS 301 can vary based on the size of the substrate 120 and / or the speed of the stage 114. In one embodiment, there are 10 IPS 301 in the processing unit 104.

[0042] Each of the IPS 301 may include a light source 352, an aperture 354, a lens 356, a suppressed prism assembly 358, a spatial light modulator (SLM) 360, and a projection optics device 366. The components of each of the plurality of IPS 301 vary depending on the SLM 360 used. Each SLM 360 includes, but is not limited to, a micro-LED array, a VCSEL, a liquid crystal display (LCD), or any solid-state electromagnetic radiation emitter, and a digital mirror device (DMD). Each SLM 360 may include a plurality of SLM pixels. Each SLM pixel may be individually controllable to project a write beam. The compilation of the plurality of SLM pixels forms a pattern written into the photoresist, referred to herein as a mask pattern. Each projection optics device 366 includes a projection lens, for projecting light onto the substrate 120, such as a 10x objective lens. In operation, based on the mask pattern data provided to the SLM 360 by the controller 110, each SLM pixel is in an "on" or "off" position. Each SLM pixel in the "on" position forms a write beam, which is then projected onto the photoresist layer surface of the substrate 120 by the corresponding projection optics 366 to form a pixel of the mask pattern. In some embodiments, each SLM 360 includes multiple mirrors, for example, multiple SLM pixels. Each of the multiple mirrors corresponds to an SLM pixel, which may correspond to a pixel of the mask pattern. In some embodiments, the SLM 360 is a DMD. In some embodiments, the DMD includes more than about 4,000,000 mirrors, while in other embodiments, it may include 1920x1080 mirrors, representing the number of pixels in a high-definition television.

[0043] Light source 352 is any suitable light source capable of generating light with a predetermined wavelength, such as a light-emitting diode (LED) or a laser. In one embodiment, the predetermined wavelength is in the blue light or near-UV range, such as less than about 450 nm. The suppressed prism assembly 358 includes a plurality of reflective surfaces. In operation, a beam 353 is generated by light source 352. The beam 353 is reflected by suppressed prism assembly 358 to SLM 360. When beam 353 reaches a mirror of SLM 360, each mirror in the "on" position reflects beam 353 to projection optics 366. Projection optics 366 then projects a plurality of write beams (e.g., "shots") 302 onto the photoresist layer surface of substrate 120. The plurality of write beams 302 form a plurality of pixels of a mask pattern.

[0044] Figure 4 This is a top view of a digital offset printing system 400 according to some embodiments. For example, system 400 shows a portion of substrate 120 below processing unit 104. Substrate 120 may be divided into a plurality of partitions 405 defining E2E boundaries 420 and B2B boundaries 430, the E2E boundaries 420 having associated E2E boundary regions (including E2E boundary regions 422-1 and 422-2), and the B2B boundaries 430 having associated B2B boundary regions (including B2B boundary region 432). In this exemplary example, there are 10 IPS 301, and substrate 120 is divided into eight partitions (e.g., scanning areas) 405, including at least one first partition 401, a second partition 402, a third partition 403, and a fourth partition 404. Each partition 405 corresponds to a corresponding exposure unit of the IPS. However, the number of partitions should not be considered limiting.

[0045] Each of partitions 405 has a partition pattern. The boundary between the first partition 401 and the second partition 402 along a row of IPS 301 is an E2E boundary 420. The boundary between the third partition 403 and the fourth partition 404 is also an E2E boundary. The boundary between the first partition 401 and the third partition 403 along a row of IPS 301 is a B2B boundary 430. The boundary between the second partition 402 and the fourth partition 404 is also a B2B boundary 430. Each IPS is operable to expose the pattern of the corresponding partition in partition 405 (e.g., one of the first partition 401, the second partition 402, the third partition 403, and the fourth partition 404) to the partition pattern and a portion of the partition on the E2E boundary 420 and another portion of the partition on the B2B boundary 430. For example, for IPS 301, the exposure area corresponds to the first partition 401, a portion of the second partition 402 on the E2E boundary 420, a portion of the third partition 403 on the B2B boundary 430, and another portion of the fourth partition 404 (where the E2E boundary 420 intersects with the B2B boundary 430). For IPS 301, the exposure area corresponds to the second partition 402, a portion of the first partition 401 on the E2E boundary 420, a portion of the fourth partition 404 on the B2B boundary 430, and another portion of the third partition 403 (where the E2E boundary 420 intersects with the B2B boundary 430).

[0046] The substrate 120 may include a photoresist material disposed on the material to be etched. This photoresist material may be a positive photoresist material (e.g., where a portion of the photoresist material exposed to radiation (e.g., light) becomes soluble in the photoresist developer) or a negative photoresist material (e.g., where a portion of the photoresist material exposed to radiation (e.g., light) becomes insoluble in the photoresist developer). Therefore, a photoresist pattern can be formed by removing designated portions of the photoresist material. In some embodiments, the material to be etched is a conductive material (e.g., a metal). For example, a conductive material may be molybdenum. After the designated areas of the photoresist material have been removed, the material now exposed can be etched according to the photoresist pattern. For example, wiring can be formed during the etching process. Alternatively, the patterned material may be photosensitive itself, thereby eliminating the need to add a photoresist layer and perform subsequent etching processes.

[0047] During digital offset printing, each exposure unit moves relative to the substrate to expose a region of the substrate (e.g., a rectangular region) to radiation (e.g., light). During scanning, the exposure unit exposes a corresponding scan area according to a programmed scan path. Instead of moving the exposure unit above the stage assembly, the stage assembly can move below the exposure unit in the XY direction according to the programmed scan path. Because the field of view of a lens assembly (e.g., a lens group) may be smaller than its associated scan area, the stage assembly may have to repeatedly move back and forth until the entire scan area is printed. The lens assembly projects to scan the scan area, except for the first and last scans, which may be trimmed based on the definition of the scan area. A larger number of exposure units allows for fewer scans to be performed, which can correspond to higher throughput.

[0048] Each exposure unit may be responsible for a different scanning area, which may or may not overlap with the adjacent scanning areas of other exposure units. To avoid a sudden transition from a first scanning area to a second scanning area adjacent to the first scanning area (either attached to the same bridging element or to different bridging elements), the exposure unit corresponding to the first scanning area may encroach into the second scanning area. Similarly, the exposure unit corresponding to the second scanning area may encroach into the first scanning area. Therefore, shared exposure can be observed at the boundaries or "match lines" between adjacent exposure units on the same bridging element and / or between exposure units on different bridging elements.

[0049] The splicing line can be defined by a shear layer, which can be a software-defined layer that sets the scan path boundary for each exposure unit during the movement of the stage assembly. Due to imperfect printing conditions, the splicing line may be visible on the substrate after printing. For example, if the actual position of the exposure unit is offset by about 1 micrometer, a 1-micrometer-wide gap or double exposure band may exist near the splicing line. Although the splicing line is shown as a straight line (making the scan area rectangular) in this illustrative example, the splicing line can be curved (e.g., wavy).

[0050] The following will be referenced Figure 6 A to Figure 6D describes the process in more detail: During scanning, the exposure units can advance along a path. More specifically, during scanning, the stage assembly moves across the scanning area in the X direction (e.g., from right to left), during which time the exposure units pattern a line on the scanning area. After reaching the left edge of the scanning area, the stage assembly moves in the Y direction (e.g., upwards) and then in the X direction (e.g., from left to right) to pattern another line on the scanning area. This path advances in this serpentine manner until it reaches the opposite end of the scanning area, at which point a complete image has been patterned on the substrate. The image can then be developed for substrate etching. According to the embodiments described herein, the distance “Y1” that the stage travels in the Y direction during scanning can be any suitable distance. In some embodiments, Y1 can be in the range of about 150 mm to about 180 mm. For example, Y1 can be about 164 mm. In some embodiments, the scanning distance of each exposure unit in the X direction corresponds to the length of the bridging element. According to the embodiments described herein, the total width “Y2” of the scanning area can be any suitable width. In some embodiments, Y2 can be in the range of about 1600 mm to about 2000 mm. For example, Y2 can be about 1800 mm. Due to differences in substrate size, the travel distance (e.g., in the X direction) for each scan can vary. For example, in some embodiments, the substrate comprises an 8-inch circular wafer. As another example, in some embodiments, the substrate comprises a 12-inch circular wafer.

[0051] Figures 5A to 5D The top views 500A to 500D according to some embodiments show the scanning path of the substrate through a single digital lithography exposure unit (“exposure unit”) 510 of the digital lithography system.

[0052] Figure 5A The scanning areas 520 of the exposure unit 510 and the substrate are marked before the first scan is performed using the exposure unit 610. Before the first scan is performed, the edge 522 of the scanning area 520 can be aligned with the edge 512 of the exposure unit 510. According to the digital lithography scanning program that performs multiple scans across the scanning area 520, the stage moves the substrate in (several) XY directions.

[0053] Figure 5B The scanned area 530-1 is formed within the scanned area 520 after the first scan is performed using the exposure unit 510. More specifically, the stage moves the substrate in the positive X direction below the exposure unit 510 to form the scanned area 530-1.

[0054] Figure 5CThe scanned area 530-2 is marked after the second scan is performed using the exposure unit 510. More specifically, after the first scan is performed using the exposure unit 510, the stage moves the substrate in the positive Y direction to align the exposure unit 510 with the next designated area, and then the stage moves the substrate under the exposure unit 510 in the negative X direction to form the scanned area 530-2.

[0055] Figure 5D The scanned area 530-2 is marked after the second scan is performed using exposure unit 510. More specifically, after the second scan is performed using exposure unit 510, the stage moves the substrate in the positive Y direction to align exposure unit 510 with the next designated area, and then the stage moves the substrate in the positive X direction below exposure unit 610 to form the scanned area 530-3. An additional scan can be performed to complete the scan.

[0056] During the aforementioned scanning process, one or more "molly" issues may be observed. One example of molly is "scan molly," which occurs after each scan. For instance, one type of scan molly is illumination inhomogeneity, where the exposure field of the exposure unit is inconsistent (e.g., the top edge of the exposure field has a different illumination field than the bottom edge). More specifically, each time a scan is performed to scan a line or "draw a stripe," the top edge of the scan will be brighter or darker than the bottom edge. This can adversely affect patterning dimensions. Another example of molly is "vibration molly," where oscillations caused by the operation of the digital lithography system can cause the exposure unit to vibrate, resulting in an uneven scan. Because the vibrations of the exposure unit may be spatially asynchronous, this can cause visible variations on the display.

[0057] Another example of moiré is "boundary moiré," where an abrupt change in appearance can be observed at the boundary or edge between an area scanned by one exposure unit and an adjacent area scanned by another exposure unit. For example, boundary moiré can occur at the boundary between the areas scanned by a pair of adjacent exposure units of a given bridging element (e.g., the boundary between scanned areas). As another example, boundary moiré can occur at the boundary between the areas scanned by a pair of adjacent exposure units corresponding to different bridging elements (e.g., the boundary between scanned areas).

[0058] There can be a variety of different microscopic and / or macroscopic causes that can lead to boundary moiré patterns. For example, if one exposure cell outputs more radiation (e.g., light) during scanning than its neighboring cells, a sudden change in the line width of the printed lines can be observed at the boundary between the exposure cells. As another example, if one exposure cell is out of focus compared to another, the photoresist sidewall profile corresponding to each exposure cell may differ. For instance, a better-focused exposure cell may have more vertical sidewalls compared to the more sloping sidewalls of an exposure cell with poor focus. Therefore, problems may exist at the boundary between adjacent scan areas.

[0059] As will be described in more detail herein, moiré (e.g., boundary moiré) can be resolved by performing exposure unit boundary smoothing to smooth the boundaries (e.g., splicing lines) between scanned areas scanned by adjacent exposure units. Exposure unit boundaries may correspond to the edges of the areas scanned by the exposure units. For example, exposure unit boundary smoothing can be performed to create a gradual transition (e.g., boundary blending) between areas scanned by different exposure units.

[0060] Figure 6 A top-view illustration 600 illustrates, according to some embodiments, the smoothing of exposure unit boundaries performed by a digital lithography system. For example, the digital lithography system may include... Figures 1 to 4 One or more of systems 100 to 400. For example, Figure 600 shows multiple scanning areas. The multiple scanning areas include an exposure unit (EYE) A scanning area 610A corresponding to EYE A, an EYE B scanning area 610B corresponding to EYE B, an EYE C scanning area 610C corresponding to EYE C, and an EYE D scanning area 610D corresponding to EYE D. EYE A and EYE B are attached to a first bridging member, and EYE C and EYE D are attached to a second bridging member that is different from and adjacent to the first bridging member. EYE A and EYE B define a first pair of adjacent EYEs (e.g., a pair of adjacent EYEs attached to the same bridging member). EYE C and EYE D define a second pair of adjacent EYEs (e.g., a pair of adjacent EYEs attached to the same bridging member). EYE A and EYE C define a third pair of adjacent EYEs (e.g., a pair of adjacent EYEs attached to different bridges). EYE B and EYE D define a fourth pair of adjacent EYEs (e.g., a pair of adjacent EYEs attached to different bridges).

[0061] The first and second pairs of adjacent eyes are separated by a nominal E2E boundary 620, and the third and fourth pairs of adjacent eyes are separated by a nominal B2B boundary 630. Therefore, the scan area 610A of Eye A corresponds to the lower left quadrant defined by the nominal E2E boundary 620 and the nominal B2B boundary 630, the scan area 610B of Eye B corresponds to the upper left quadrant defined by the nominal E2E boundary 620 and the nominal B2B boundary 630, the scan area 610C of Eye C corresponds to the lower right quadrant defined by the nominal E2E boundary 620 and the nominal B2B boundary 630, and the scan area 610D of Eye D corresponds to the upper right quadrant defined by the nominal E2E boundary 620 and the nominal B2B boundary 630. In this example, the scanning direction of the scan path used from Eye A to Eye D is shown as a horizontal direction advancing from left to right. (See above reference.) Figures 4 to 5D Additional details about the scan path are described.

[0062] In this example, dose mixing can be controlled for the first and second pairs of adjacent eyes in a direction perpendicular to the scanning direction. More specifically, the target doses assigned to Eye A and Eye B of the first pair of adjacent eyes and the target doses assigned to Eye C and Eye D of the second pair of adjacent eyes are based on their position relative to the underlying substrate in a direction perpendicular to the scanning direction.

[0063] For example, Eye A and Eye C may each be assigned to provide the total dose in region 640, Eye B and Eye D may each be assigned to provide the total dose in region 642, and Eye A through Eye D may each be assigned to provide a corresponding target dose (each less than the total dose) within the E2E mixing region 645 having a total area. More specifically, the E2E mixing region 645 may be divided into multiple sub-regions, wherein each sub-region of the E2E mixing region 645 is formed by a corresponding portion of the total area of ​​the E2E mixing region 645. Each sub-region of the E2E mixing region 645 may have an associated dose ratio that defines the target dose of the third exposure unit and the target dose of the fourth exposure unit within the sub-region.

[0064] Typically, the dose ratio can range from 1:N to N:1, where N is the number of sub-regions of the E2E blending region 645. In some embodiments, N can range from 3 to 6. The E2E blending region 645 may have an associated height (H). In some embodiments, H ranges from about 5 mm to about 20 mm. Therefore, each sub-region of the E2E blending region 645 may have a width H / N. In this exemplary example, the number of sub-regions of the E2E blending region 645 is three (e.g., N=3), and each sub-region of the E2E blending region 645 may have a width H / 3.

[0065] For example, subregion 650 of E2E blending region 645 may define a dose ratio in which EYE A and EYE C each provide a target dose equal to approximately 75% of the total dose, and EYE B and EYE D each provide a target dose equal to approximately 25% of the total dose. As another example, subregion 652 of E2E blending region 645 may be located adjacent to region 642 and may define a dose ratio in which EYE A and EYE C each provide a target dose equal to approximately 25% of the total dose, and EYE B and EYE D each provide a target dose equal to approximately 75% of the total dose. As yet another example, subregion 654 of E2E blending region 645 may be located between subregion 650 and subregion 625 and may define a dose ratio in which EYE A, EYE B, EYE C, and EYE D each provide a target dose equal to approximately 50% of the total dose. Therefore, the dose mixing described herein can be used to perform E2E boundary smoothing between adjacent EYEs attached to the same bridging element.

[0066] Jitter can be controlled for the third and fourth pairs of adjacent eyes. More specifically, for the third pair of adjacent eyes, one of eye A or eye C can be selected to provide its target dose based on its position relative to the underlying substrate along the scanning direction (e.g., determined by dose mixing). For the fourth pair of adjacent eyes, one of eye B or eye D can be selected to provide its target dose based on its position relative to the underlying substrate along the scanning direction (e.g., determined by dose mixing). For example, eye A and eye B can be assigned to provide their target dose in sub-region 660, eye C and eye D can be assigned to provide their target dose in sub-region 662, and eye A through eye D can each be assigned to provide their target dose within the B2B mixed sub-region 650 or B2B mixed region 665 having a total area.

[0067] More specifically, the B2B blending region 665 may be divided into multiple sub-regions, each of which is formed by a corresponding portion of the total area of ​​the B2B blending region 665. Each sub-region of the B2B blending region 665 may have an associated area ratio that defines the amount of area within each of the sub-regions assigned to be scanned in EYE A to EYE D. Typically, the area ratio may range from 1:M to M:1, where M is the number of sub-regions of the B2B blending region 665. In some embodiments, M may range from 3 to 6. The B2B blending region 665 may have an associated width (W). In some embodiments, W ranges from about 5 mm to about 20 mm. Thus, each sub-region of the B2B blending region may have a width W / M. In this exemplary example, the number of sub-regions of the B2B blending region is four (e.g., M=4), and each sub-region of the B2B blending region may have a width W / 4.

[0068] For example, a sub-region 670 of the B2B blending region 665 may be located adjacent to the sub-region 660. The sub-region 670 may define a first area ratio, wherein EYE A and EYE B each scan a portion of the area of ​​the sub-region 670, and EYE C and EYE D each scan the remaining portion of the area of ​​the sub-region 670. In some embodiments, the first area ratio is approximately 1:4, with EYE A and EYE B each scanning approximately 80% of the area of ​​the sub-region 670, and EYE C and EYE D each scanning approximately 20% of the remaining area of ​​the sub-region 670.

[0069] As another example, a sub-region 672 of the B2B blending region 665 may be located adjacent to the sub-region 662. The sub-region 672 may define a second area ratio, wherein EYE C and EYE D each scan a portion of the area of ​​the sub-region 654, and EYE A and EYE B each scan the remaining portion of the area of ​​the sub-region 672. In some embodiments, the second area ratio is approximately 4:1, with EYE C and EYE D each scanning approximately 80% of the area of ​​the sub-region 672, and EYE A and EYE B each scanning approximately 20% of the remaining area of ​​the sub-region 672.

[0070] As another example, a sub-region 674 of the B2B blending region 665 may be located adjacent to sub-region 670. Sub-region 674 may define a third area ratio, wherein EYE A and EYE B each scan a portion of the area of ​​sub-region 674, and EYE C and EYE D each scan the remaining portion of the area of ​​sub-region 674. In some embodiments, the third area ratio is approximately 2:3, with EYE A and EYE B each scanning approximately 60% of the area of ​​sub-region 674, and EYE C and EYE D each scanning approximately 40% of the remaining portion of sub-region 674.

[0071] As another example, a sub-region 676 of the B2B blending region 665 may be located between sub-regions 672 and 674. Sub-region 676 may define a fourth area ratio, wherein Eye C and Eye D each scan a portion of the area of ​​sub-region 676, and Eye A and Eye B each scan the remaining portion of the area of ​​sub-region 676. In some embodiments, the fourth area ratio is approximately 3:2, with Eye C and Eye D each scanning approximately 60% of the area of ​​sub-region 676, and Eye A and Eye B each scanning approximately 40% of the remaining area of ​​sub-region 676. Therefore, the jitter described herein can be used to perform B2B boundary smoothing between adjacent Eyes attached to different bridging elements. References above Figure 1 Figure 5 describes the information about Figure 6 Further details will now be provided in the following references. Figure 7 Describe it.

[0072] Figure 7 A flowchart of a method 700 for achieving edge smoothing of exposure units in digital lithography is depicted according to some embodiments. This method can be executed by processing logic, which may include hardware (circuit systems, dedicated logic, etc.), computer-readable instructions (running on a general-purpose computer system or a dedicated machine), or a combination of both. In an exemplary example, method 700 may be executed by the processing apparatus of a digital lithography system. It should be noted that... Figure 7 The boxes depicted can be executed simultaneously with or in a different order than the situations depicted.

[0073] At block 710, the processing logic receives instructions to perform a digital lithography process to pattern a substrate using a digital lithography system, and at block 720, the processing logic initiates the digital lithography process to pattern the substrate according to the instructions. The substrate may be placed on a stage, and the stage may be moved in the XY direction below the exposure unit according to the instructions. For example, instructions may be executed to achieve exposure unit boundary smoothing (e.g., exposure unit boundary offset and / or dose mixing).

[0074] At box 730, the processing logic performs exposure cell boundary smoothing during the digital lithography process. Exposure cell boundary smoothing can be performed to reduce inhomogeneities within the scanned areas scanned by adjacent exposure cells (EYE). EYE boundary smoothing can blend boundaries, such as B2B boundaries and / or E2E boundaries, to create a more gradual transition between boundaries, thereby reducing the visible irregularities that are perceptible to the human eye. In some embodiments, EYE boundary smoothing is performed to smooth E2E and B2B boundaries in multiple directions.

[0075] In some embodiments, performing eye boundary smoothing during a digital lithography process includes controlling the area ratio of a first pair of adjacent eyes in a first direction (e.g., controlling jitter in the first direction) and controlling the dose ratio of a second pair of adjacent eyes in a second direction perpendicular to the first direction (e.g., controlling dose mixing in the second direction). In some embodiments, the first direction is the scanning direction, and the second direction is a direction perpendicular to the scanning direction. For example, the scanning direction may be horizontal, as viewed from a top viewpoint (e.g., from left to right) of the digital lithography system.

[0076] The first pair of adjacent eyes may include a first eye attached to a first bridging member and a second eye attached to a second bridging member adjacent to the first bridging member, wherein a nominal B2B boundary separates a first scan region defined for the first eye and a second scan region defined for the second eye. More specifically, one of the first eye or the second eye may be selected to provide its target dose based on the position of the eye relative to the substrate along a first direction. For example, the first eye may be assigned to provide its target dose in a first sub-region, the second eye may be assigned to provide its target dose in a second sub-region, and both the first and second eye may be assigned to provide their target dose in a third sub-region having a total area. The third sub-region may be referred to as a B2B mixing region. More specifically, the B2B mixing region may be divided into multiple sub-regions, wherein each sub-region of the B2B mixing region is formed from a corresponding portion of the total area of ​​the B2B mixing region. Each subregion of the B2B blending region may have an associated area ratio that defines the amount of area assigned to the first EYE scan and the amount of area assigned to the second EYE scan within the subregion.

[0077] The second pair of adjacent eyes may include a third eye and a fourth eye attached to the same bridging element, wherein a nominal E2E boundary separates a third scan region defined for the third eye and a fourth scan region defined for the fourth eye. The dose ratio may be defined based on the position relative to the substrate along a second direction to define the target dose of the third eye and the target dose of the fourth eye.

[0078] The area ratio of a first pair of adjacent eyes in a first direction can interact with the dose ratio of a second pair of adjacent eyes in a second direction. For example, the first eye can also be a third eye, such that the first pair of adjacent eyes includes both the first and second eye, and the second pair of adjacent eyes includes both the first and fourth eye. Therefore, the B2B boundary can separate the first and second eye, the E2E boundary can separate the first and fourth eye, and the target dose determined for the first eye based on the dose ratio for dose mixing with respect to the second eye is the target dose applied based on the area ratio for jittering with respect to the fourth eye. (See above reference.) Figures 1 to 6 Further details regarding boxes 710 to 730 are described.

[0079] Figure 8 A block diagram of a computer system 800 according to certain embodiments is shown. In some embodiments, computer system 800 is connected to other computer systems (e.g., via a network 874, such as a local area network (LAN), intranet, extranet, or Internet). In some embodiments, computer system 800 operates as a server or client computer in a client-server environment, or as a peer computer in a peer-to-peer or distributed network environment. In some embodiments, computer system 800 is provided by a personal computer (PC), tablet PC, set-top box (STB), personal digital assistant (PDA), cellular phone, web facility, server, network router, switch, or bridge, or any means capable of executing a set of instructions (sequentially or otherwise) specifying actions to be taken by another device. Additionally, the term "computer" should include any collection of computers that individually or jointly execute a set (or more) of instructions to perform any one or more methods described herein.

[0080] In another aspect, the computer system 800 includes a processing device 802, volatile memory 804 (e.g., random access memory (RAM)), non-volatile memory 806 (e.g., read-only memory (ROM) or electrically erasable programmable ROM (EEPROM)), and data storage device 816, which communicate with each other via a bus 808.

[0081] In some embodiments, the processing device 802 is provided by one or more processors, such as general-purpose processors (e.g., Complex Instruction Set Computing (CISC) microprocessors, Reduced Instruction Set Computing (RISC) microprocessors, Very Long Instruction Word (VLIW) microprocessors, microprocessors implementing other types of instruction sets, or microprocessors implementing a combination of multiple types of instruction sets), or special-purpose processors (e.g., Application Specific Integrated Circuit (ASIC), Field Programmable Gate Array (FPGA), Digital Signal Processor (DSP), or Network Processor).

[0082] In some embodiments, the computer system 800 further includes a network interface device 822 (e.g., coupled to a network 874). In some embodiments, the computer system 800 also includes a video display unit 810 (e.g., an LCD), an alphanumeric input device 812 (e.g., a keyboard), a cursor control device 814 (e.g., a mouse), and a signal generation device 820.

[0083] In some implementations, the data storage device 816 includes a non-transitory computer-readable storage medium 824 storing instructions 826 that encode one or more of the methods or functions described herein. For example, the instructions 826 may include instructions for controlling the movement of the stage and / or exposure unit of a digital lithography system, which, when executed, implement the methods described herein for performing exposure unit boundary smoothing.

[0084] In some embodiments, the instructions 826 are also wholly or partially residing in the volatile memory 804 and / or the processing device 802 during execution by the computer system 800, and thus, in some embodiments, the volatile memory 804 and the processing device 802 also constitute machine-readable storage media.

[0085] Although computer-readable storage medium 824 is shown as a single medium in the illustrative example, the term "computer-readable storage medium" should include a single medium or multiple media (e.g., a centralized or distributed database and / or associated caches and servers) that store one or more sets of executable instructions. The term "computer-readable storage medium" should also include any tangible medium capable of storing or encoding a set of instructions for execution by a computer, which causes the computer to perform any or more of the methods described herein. The term "computer-readable storage medium" should include, but is not limited to, solid-state memory, optical media, and magnetic media.

[0086] In some embodiments, the methods, components, and features described herein are implemented through discrete hardware components or integrated into the functionality of other hardware components, such as ASICs, FPGAs, DSPs, or similar devices. In some embodiments, these methods, components, and features are implemented through firmware modules or functional circuitry systems within a hardware device. In some embodiments, these methods, components, and features are implemented in any combination of hardware devices and computer program components or in a computer program.

[0087] Unless otherwise expressly stated, terms such as “receive,” “initiate,” “execute,” etc., refer to actions and processes performed or implemented by a computer system that manipulate data represented as physical (electronic) quantities within computer system caches and memories and transform that data into other data similarly represented as physical quantities within computer system memory or caches or other such information storage, transmission, or display devices. In some embodiments, as used herein, the terms “first,” “second,” “third,” “fourth,” etc., are labels used to distinguish different elements and do not have ordinal meaning according to their numerical designation.

[0088] The examples described herein also relate to apparatus for performing the methods described herein. In some embodiments, this apparatus is specifically configured to perform the methods described herein, or comprises a general-purpose computer system selectively programmed by a computer program stored in a computer system. This computer program is stored in a computer-readable tangible storage medium.

[0089] The methods and illustrative examples described herein are not inherently related to any particular computer or other device. In some embodiments, various general-purpose systems are used in accordance with the teachings described herein. In some embodiments, more specialized devices are constructed to perform each of the methods described herein and / or their individual functions, routines, subroutines, or operations. Examples of structures for various such systems are illustrated in the foregoing description.

[0090] The foregoing description sets forth numerous specific details, such as examples of particular systems, components, methods, etc., to provide a good understanding of several embodiments of the invention. However, those skilled in the art will recognize that at least some embodiments of the invention can be practiced without these specific details. In other instances, well-known components or methods have not been described in detail or have been presented in the form of simple block diagrams to avoid unnecessarily obscuring the invention. Therefore, the specific details set forth are merely illustrative. Specific implementations may differ from these illustrative details and are still contemplated within the scope of the invention.

[0091] Throughout this specification, references to "an embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing throughout this specification do not necessarily refer to the same embodiment. Additionally, the term "or" is intended to mean inclusive rather than exclusive. When the terms "about" or "approximately" are used herein, this is intended to mean that the presented nominal value is exactly within ±10%.

[0092] Although the operations of the methods are shown and described in a specific order herein, the order of operations of each method may be changed so that certain operations can be performed in reverse order, or so that certain operations can be performed at least partially concurrently with other operations. In another embodiment, instructions or sub-operations of dissimilar operations may be performed intermittently and / or alternately.

[0093] It should be understood that the above description is intended to be illustrative and not restrictive. After reading and understanding the above description, those skilled in the art will understand many other implementation examples. Although this disclosure describes specific examples, it should be recognized that the systems and methods of this disclosure are not limited to the examples described herein, but can be practiced with modifications within the scope of the appended claims. Therefore, the specification and drawings should be considered in an illustrative rather than restrictive sense. Consequently, the scope of this disclosure should be determined by referring to the appended claims together with the equivalents conferred by such claims.

Claims

1. A digital lithographic printing system, the digital lithographic printing system comprising: Memory; as well as At least one processing device, operatively coupled to the memory to perform operations including: Initiate a digital lithography process to pattern a substrate using the digital lithography system; Controlling the area ratio of the first pair of adjacent exposure units relative to the digital lithography system in a first direction; and Control the dose ratio of the second pair of adjacent exposure units relative to the digital lithography system in a second direction perpendicular to the first direction.

2. The digital offset printing system as claimed in claim 1, wherein the first direction is the scanning direction.

3. The digital offset printing system as described in claim 1, wherein: The first pair of adjacent exposure units includes a first exposure unit attached to a first bridging member and a second exposure unit attached to a second bridging member adjacent to the first bridging member; and The second pair of adjacent exposure units includes a third exposure unit and a fourth exposure unit, each attached to a third bridging member.

4. The digital offset printing system of claim 3, wherein the area ratio defines a first area amount assigned to the first exposure unit for scanning and a second area amount assigned to the second exposure unit for scanning based on the position relative to the substrate along the first direction.

5. The digital offset printing system of claim 3, wherein the dose ratio defines a first target dose assigned to the third exposure unit and a second target dose assigned to the fourth exposure unit based on the position relative to the substrate along the second direction.

6. The digital offset printing system of claim 3, wherein the first exposure unit is the third exposure unit.

7. The digital lithography system of claim 1, wherein the area ratio and the dose ratio are controlled to smooth the boundaries between corresponding exposure units of the digital lithography system during the digital lithography process.

8. A method for performing exposure unit boundary smoothing, the method comprising: A digital lithography process is initiated by at least one processing device to pattern a substrate using a digital lithography system; The area ratio of the first pair of adjacent exposure units relative to the digital lithography system in a first direction is controlled by the at least one processing device; as well as The dose ratio of a second pair of adjacent exposure units relative to the digital lithography system in a second direction perpendicular to the first direction is controlled by the at least one processing device.

9. The method for performing exposure unit boundary smoothing as described in claim 8, wherein the first direction is a scanning direction.

10. The method for performing exposure unit boundary smoothing as described in claim 8, wherein: The first pair of adjacent exposure units includes a first exposure unit attached to a first bridging member and a second exposure unit attached to a second bridging member adjacent to the first bridging member; and The second pair of adjacent exposure units includes a third exposure unit and a fourth exposure unit, each attached to a third bridging member.

11. The method of performing exposure unit boundary smoothing as claimed in claim 10, wherein the area ratio defines a first area amount assigned to scan the first exposure unit and a second area amount assigned to scan the second exposure unit based on the position relative to the substrate along the first direction.

12. The method of performing exposure unit boundary smoothing as claimed in claim 10, wherein the dose ratio defines a first target dose assigned to the third exposure unit and a second target dose assigned to the fourth exposure unit based on the position relative to the substrate along the second direction.

13. The method for performing exposure unit boundary smoothing as described in claim 10, wherein the first exposure unit is the third exposure unit.

14. The method for performing exposure unit boundary smoothing as claimed in claim 8, wherein the area ratio and the dose ratio are controlled to smooth the boundaries between corresponding exposure units of the digital lithography system during the digital lithography process.

15. A digital lithography system, the digital lithography system comprising: A worktable, which is associated with multiple scanning areas; Multiple exposure units are located above the worktable, wherein the multiple exposure units include a first pair of adjacent exposure units and a second pair of adjacent exposure units; At least one processing device, operatively coupled to a memory to perform operations, the operations including: Initiate a digital offset printing process to pattern a substrate placed on the worktable; Controlling the area ratio relative to the first pair of adjacent exposure units in a first direction; and Control the dose ratio relative to the second pair of adjacent exposure units in a second direction perpendicular to the first direction.

16. The digital lithography system of claim 15, wherein the first direction is the scanning direction.

17. The digital offset printing system of claim 15, wherein: The first pair of adjacent exposure units includes a first exposure unit attached to a first bridging member and a second exposure unit attached to a second bridging member adjacent to the first bridging member; and The second pair of adjacent exposure units includes a third exposure unit and a fourth exposure unit, each attached to a third bridging member.

18. The digital offset printing system of claim 17, wherein the area ratio defines a first area amount assigned to the first exposure unit for scanning and a second area amount assigned to the second exposure unit for scanning based on the position relative to the substrate along the first direction.

19. The digital offset printing system of claim 17, wherein the dose ratio defines a first target dose assigned to the third exposure unit and a second target dose assigned to the fourth exposure unit based on the position relative to the substrate along the second direction.

20. The digital offset printing system of claim 17, wherein the first exposure unit is the third exposure unit.

Images