Digital lithography scan ordering

Abstract

A digital lithographic printing system includes adjacent scan areas, an exposure unit positioned over the scan areas, a memory, and a processing device operatively coupled to the memory. The exposure units include a first exposure unit associated with the first scanning area and a second exposure unit associated with the second scanning area. The processing device is to initiate a digital lithographic printing process to pattern a substrate disposed on a platform according to instructions. The processing device is further configured to perform, at a first time, a first pass of the first exposure unit over a splice region at an interface of the first scanning region and the second scanning region. The processing device is further configured to perform a second pass of the second exposure unit over the splicing area at a second time that differs from the first time by less than forty seconds.

Description

Technical Field

[0001] This specification relates generally to electronic component manufacturing. More specifically, this specification relates to digital lithography. Background Art

[0002] Photolithography is used to manufacture semiconductor devices and display devices, such as flat panel displays. Examples of flat panel displays include thin-film displays, such as liquid crystal display (LCD) devices and organic light-emitting diode (OLED) displays. Large-area substrates can be used to manufacture flat panel displays for use with computers, touch panel devices, personal digital assistants (PDAs), cellular phones, television monitors, and the like.

[0003] In digital lithography, multiple exposure units are used to increase throughput, with each unit responsible for a portion of the printed area. However, delays in scanning at boundaries can cause irregularities in the resulting features. This can result in visible boundaries between areas printed by different exposure units. For display devices, visible boundaries can be a defect that can render the resulting display scrapped. Summary of the Invention

[0004] The following is a brief summary of the disclosure to provide a basic understanding of some aspects of the disclosure. This summary is not an exhaustive overview of the disclosure. It is not intended to identify important or critical elements of the disclosure, nor is it intended to delineate any scope of specific embodiments of the disclosure or any scope 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 will be presented later.

[0005] According to at least one embodiment, a digital lithography system is provided. The digital lithography system includes a plurality of scanning areas, the scanning areas including a first scanning area and a second scanning area adjacent to the first scanning area. The digital lithography system further includes a plurality of exposure units located above the plurality of scanning areas. The plurality of exposure units includes a first exposure unit associated with the first scanning area and a second exposure unit associated with the second scanning area. The digital lithography system further includes a memory and at least one processing device operatively coupled to the memory. The at least one processing device is used to initiate a digital lithography process to pattern a substrate disposed on a platform according to instructions. The at least one processing device is further used to perform a first pass of the first exposure unit over a stitching area at an interface between the first scanning area and the second scanning area at a first time. The at least one processing device is further used to perform a second pass of the second exposure unit over the stitching area at a second time that is less than forty seconds different from the first time.

[0006] According to at least one embodiment, a system is provided. The system includes a memory and at least one processing device operatively coupled to the memory. The at least one processing device is configured to initiate a digital lithography process to pattern a substrate according to instructions. The at least one processing device is further configured to perform a first pass of a first exposure unit over a tiled area at an interface between a first scan area of ​​a plurality of scan areas and a second scan area of ​​the plurality of scan areas at a first time. The at least one processing device is further configured to perform a second pass of a second exposure unit over the tiled area at a second time that is less than forty seconds different from the first time.

[0007] According to at least one embodiment, a method is provided. The method includes initiating, by a processing device, a digital lithography process to pattern a substrate according to instructions. The method further includes performing, at a first time, a first pass of a first exposure unit over a stitching area at an interface between a first scan area of ​​a plurality of scan areas and a second scan area of ​​the plurality of scan areas. The method further includes performing a second pass of a second exposure unit over the stitching area at a second time that is less than forty seconds different from the first time. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Aspects and embodiments of the present disclosure will be more fully understood from the detailed description given below and the accompanying drawings, which are intended to illustrate aspects and embodiments by way of example and not limitation.

[0009] Figure 1 is a top-down view of a digital lithography system according to some embodiments.

[0010] Figures 2A to 2Dis a top-down view illustrating a scan path of a substrate through a single digital lithography exposure unit of a digital lithography system, according to some embodiments.

[0011] Figures 3A to 3D is a top-down view illustrating a scan path of a substrate through a single digital lithography exposure unit of a digital lithography system, according to some embodiments.

[0012] Figures 4A to 4C is a diagram illustrating an example of digital lithography exposure unit boundary smoothing according to some embodiments.

[0013] Figure 5 is a diagram of an example scanning configuration of a digital lithography exposure unit in a single-bridge embodiment, according to some embodiments.

[0014] Figures 6A to 6B is a diagram of an example scanning sequence of a digital lithography exposure unit with respect to time, according to some embodiments.

[0015] Figure 7 is a diagram illustrating features formed on a substrate by a digital lithography process, according to some embodiments.

[0016] Figure 8 is a flow chart of a method for implementing digital lithography scan sequencing, according to some embodiments.

[0017] Figure 9 is a block diagram of a digital lithography system according to some embodiments.

[0018] Figure 10 is a block diagram illustrating a computer system, according to certain embodiments. DETAILED DESCRIPTION

[0019] Digital lithography can be used to create patterns (e.g., etch masks for digital alignment) onto a substrate surface without the use of a photomask (e.g., by maskless lithography). Digital lithography techniques (e.g., such as Texas Instruments) Programmable light steering technology) enables high-speed and high-resolution maskless lithography solutions for printed circuit board (PCB) patterning, solder masks, flat panel displays, laser marking, and other digital exposure systems that benefit from high speed and precision. Digital lithography is used to expose patterns directly onto a photoresist film without using a contact mask (e.g., a photomask). This can reduce material costs, improve production rates, and allow for rapid changes in patterns. Direct exposure increases productivity compared to narrow laser beam or shadowed systems. The advantage of digital lithography is the ability to change the lithographic pattern from one run to the next without the cost of generating a new photomask. Illustratively, digital lithography can be used to perform large-area patterning during electronic component manufacturing.

[0020] In digital lithography, multiple digital lithography exposure units ("exposure units") can be used to improve the throughput of a digital lithography tool. Conventional exposure units can print or expose rectangular non-overlapping areas, or crop layers. The crop layer can be used as a filter to inform the layout processing software to maintain the pattern that a particular exposure unit is to print on the crop layer associated with that exposure unit. Each of the multiple exposure units can be responsible for a portion of the printing area and for a different crop layer. Scanning at the boundaries of the exposure units can be delayed from one scan to another. This delay can cause non-uniformity (e.g., non-uniformity, inconsistency, irregularity) at the boundaries of the exposure units (e.g., "stitching areas"). This non-uniformity can reduce yield and therefore reduce value.

[0021] Exposure units often sequentially scan sub-portions of a portion of the print area to increase throughput. For example, an exposure unit may scan a first portion of the print area, followed by an adjacent second portion, an adjacent third portion, and so on. Because adjacent exposure units move together across the print area, sequentially scanning sub-portions of the print area results in scanning delays between adjacent exposure units at exposure unit boundaries (e.g., at a stitching area). Scanning delays can result in anomalies in features formed by the scan. These anomalies can lead to variations in critical dimensions, which in turn require product scrapping, thereby reducing overall yield.

[0022] Aspects and embodiments of the present disclosure address these and other shortcomings of the prior art by performing scans using digital lithography scan sequencing to reduce the delay between scans of a stitched area at the interface between exposure unit boundaries. Reducing the delay between scans of a stitched area can reduce anomalies in features printed in the stitched area and can result in a gradual transition between the pair of exposure units. According to the embodiments described herein, at least two different scan sequences can be used to perform digital lithography scans. In some embodiments, an inside-out scan sequence can be implemented such that scans of a stitched area at the boundary of two adjacent scan areas by two adjacent exposure units occur sequentially, one scan following the next. In some embodiments, an outside-in scan sequence can be similarly implemented. Scanning the stitched area first with a first exposure unit and then with a second exposure unit reduces the delay between scans, thereby resulting in more uniform features on the substrate, particularly at the stitched area. In some embodiments, the delay between scanning the stitched area with the first exposure unit and scanning the stitched area with the second exposure unit is less than forty seconds.

[0023] In some embodiments, a first sub-region of the scanning area of ​​the first exposure unit near an edge of the scanning area (e.g., within the exposure unit boundary) is scanned, followed by a second sub-region near the opposite edge of the scanning area. The first sub-region and the second sub-region may be a stitched region associated with the scanning area and an adjacent scanning area. A third sub-region near the first sub-region is scanned, followed by a fourth sub-region near the second sub-region, and so on, until all sub-regions of the scanning area have been scanned. The sequence described above may be referred to as an outside-in scanning sequence. This will be discussed later in this document with respect to Figure 2A With Figure 2D Further details regarding the outside-in scanning sequence are described.

[0024] In some embodiments, a first sub-region (e.g., an inner sub-region, a central sub-region, etc.) of the scanning area is scanned near the center line of the scanning area, followed by scanning a second sub-region near the first sub-region. A third sub-region is then scanned near the first sub-region on the side opposite the first sub-region from the second sub-region. Scanning continues until both edge sub-regions of the scanning area are scanned. The edge sub-regions may be a spliced ​​region associated with the scanning area and an adjacent scanning area. The sequence described above may be referred to as an inside-out scanning sequence. This will be discussed later in this document with respect to the scanning sequence. Figure 3A With Figure 3D Further details about the inside-out scanning sequence are described.

[0025] Aspects and embodiments of the present disclosure offer technical advantages over other approaches. For example, as mentioned above, non-uniformity at the boundary between a pair of adjacent exposure units (e.g., at a stitching region) and / or at the boundary between a pair of scans associated with a given exposure unit can be reduced. This can result in improved photolithography for patterning substrates.

[0026] Figure 1 1 is a top-down view of a digital lithography system ("system") 100, according to some embodiments. As shown, digital lithography system 100 includes a platform assembly 110, which includes a base (e.g., a granite base), a platform, and a substrate disposed on the platform. The substrate may be a glass plate, a wafer, a PCB, or other types of substrates. The substrate may correspond to or be positioned within a digital lithography printing or scanning area, which may include several scanning areas, including scanning areas 112-1 through 112-4. The left portion of platform assembly 110 corresponds to a first bridge 114-1 above platform assembly 110, and the right portion of platform assembly 110 corresponds to a second bridge 114-2 above platform assembly 110. Exposure units are attached to bridges 114-1 and 114-2. In some embodiments, the length of each bridge 114-1 and 114-2 may vary between approximately 500 mm and approximately 1000 mm. For example, the length of each bridge 114-1 and 114-2 may be approximately 750 mm.

[0027] The substrate can include a photoresist material provided on the material to be etched. The photoresist material can be a positive photoresist material (that is, a part of the photoresist material exposed to light becomes soluble in a photoresist developer) or a negative photoresist material (that is, a part of the photoresist material exposed to light becomes insoluble in a photoresist developer). Therefore, by removing the specified portion of the photoresist material, a photoresist pattern can be formed. In some embodiments, the material to be etched is a conductive material (for example, a metal). For example, the conductive material can be molybdenum. After removing the specified area of ​​the photoresist material, 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 can itself be photosensitive, thereby eliminating the need to add a photoresist layer and performing subsequent etching processes.

[0028] To perform photoresist patterning, digital lithography system 100 further includes a first column of digital lithography exposure units ("exposure units") suspended from first bridge 114-1, and a second column of exposure units suspended from second bridge 114-2. For example, the first column of exposure units includes exposure units 1 through 11 and the second column of exposure units includes exposure units 12 through 22. Thus, in this illustrative example, a total of 22 exposure units are shown. However, Figure 1 The number of exposure units shown should not be considered limiting, and digital lithography system 100 may include any suitable number of exposure units according to the embodiments described herein.

[0029] Each exposure unit can include a lens assembly that can project an image onto the photoresist material of the substrate. Each lens assembly is shown adjacent to the lower right corner of its associated scanning area. For example, lens assembly 120 of exposure unit 1 is associated with scanning area 112-1. In some embodiments, each lens assembly is approximately 4 mm high and approximately 3 mm wide. However, each lens assembly can have any suitable size depending on the embodiments described herein.

[0030] During the digital lithography process, each exposure unit moves relative to the substrate to expose an area of ​​the substrate (e.g., a rectangular area) to electromagnetic radiation, such as light (e.g., ultraviolet light, near-ultraviolet light, etc.). During scanning, the exposure unit exposes the corresponding scan area according to a programmed scan path. Instead of moving the exposure unit above the platform assembly 110, the platform assembly 110 can move in the XY directions below the exposure unit according to the programmed scan path. Because the field of view of a lens assembly (e.g., lens assembly 120) can be smaller than its associated scan area (e.g., scan area 112-1), the platform assembly 110 may have to be repeatedly moved back and forth until the entire scan area (e.g., scan area 112-1) is printed. The projection lens assembly 120 scans the scan area 112-1, except for the first and last scans, where trimming may occur based on the resolution of the scan area 112-1. The greater the number of exposure units, the fewer scans that can be performed, which can correspond to higher throughput.

[0031] Each exposure unit can be responsible for a different scan area, which may or may not overlap with adjacent scan areas of other exposure units. To avoid an abrupt transition from a first scan area to a second scan area adjacent to the first (attached to the same bridge or a different bridge), the exposure unit corresponding to the first scan area can intrude into the second scan area. Similarly, the exposure unit corresponding to the second scan area can intrude into the first scan area. For example, exposure unit 1 can intrude into scan area 112-2 and / or scan area 112-3, and exposure unit 2 can intrude into scan area 112-1 and / or scan area 112-4. Thus, shared exposure can be observed at the boundaries or "stitching lines" between adjacent exposure units on the same bridge and / or exposure units on different bridges.

[0032] The stitching line can be defined by a clipping layer, which can be a software-defined layer that sets the scan path boundaries for each exposure unit during movement of the platform assembly 110. Due to non-ideal printing conditions, the stitching line may be visible on the substrate after printing. For example, if the actual position of the exposure unit is shifted by about 1 micron, a 1 micron wide gap or double exposure band may exist near the stitching line. Although the stitching line in this illustrative example is shown as a straight line (so that the scan area is rectangular in shape), the stitching line can be curved (e.g., wavy).

[0033] Path 130 of exposure unit 120-1 is illustratively depicted. Path 130 can proceed in a back-and-forth manner. More specifically, during a scan, platform assembly 110 moves across scan area 120-1 in the X direction (i.e., from right to left), during which exposure unit 120-1 patterns a line across scan area 120-1. After reaching the left edge of scan area 112-1, platform assembly 110 moves in the Y direction (i.e., up or down) and then moves back in the X direction (i.e., from left to right) to pattern another line across scan area 120-1. Platform assembly 110 then moves again in the Y direction (i.e., up or down) and then again in the X direction (i.e., from right to left). Path 130 can proceed in this back-and-forth manner until the entire scan area 120-1 has been scanned, at which point a complete image has been patterned on the substrate. The image can then be developed for etching the substrate. According to embodiments described herein, the distance "Y1" that the platform travels in the Y direction during a scan can be any suitable distance. In some embodiments, Y1 can vary between about 150 mm and about 180 mm. For example, Y1 can be about 164 mm. In embodiments, the scanning distance of each exposure unit in the X direction corresponds to the length of bridges 114-1 and 114-2. According to embodiments described herein, the total width "Y2" of the scanning area can be any suitable width. In some embodiments, "Y2" can vary between about 1600 mm and 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 be different. For example, in some embodiments, the substrate comprises an 8-inch round wafer. As another example, in some embodiments, the substrate comprises a 12-inch round wafer.

[0034] In some embodiments, Figure 1 The scanning process shown can be used to produce a display (e.g., a flat panel display). In some embodiments, the display is a liquid crystal display (LCD). Further details about the scanning path 130 exposure unit 120-1 will now be referred to below. Figures 2A to 2D describe.

[0035] Figures 2A to 2D FIG2 is a top-down view 200A-200D of an outside-in scanning path of a substrate through a scanning area 220 of a single digital lithography exposure unit (“exposure unit”) 210 of a digital lithography system according to some embodiments. The exposure unit 210 may be, for example, the one described above with reference to FIG2. Figure 1 The exposure unit 120 - 1 of the digital lithography system 100 is depicted. The substrate is positioned on a platform (not shown). In some embodiments, the first designated area to be scanned (eg, a sub-area of ​​the scanning area 220 ) may be near an edge of the scanning area 220 .

[0036] Figure 2A The exposure unit 210 and a scan area 220 of the substrate are shown before a first scan is performed using the exposure unit 210. Before the first scan is performed, an edge 222 of the scan area 220 can be aligned with an edge 212 of the exposure unit 210. The stage moves the substrate in the XY directions according to a digital lithography scanning program, thereby performing multiple scans across the scan area 220.

[0037] Figure 2B The formation of scan area 230-1 within scan area 220 is shown after the first scan is performed using exposure unit 210. More specifically, the stage moves the substrate in the positive X-direction beneath exposure unit 210 to form scan area 230-1. In some embodiments, scan area 230-1 and / or scan area 230-2 correspond to a tiled area associated with scan area 220 and an adjacent scan area. Scan areas, such as scan area 230-1, may be referred to as sub-areas of scan area 220. The amount of time that exposure unit 210 spends scanning scan area 230-1 may be referred to as a scan duration.

[0038] Figure 2C The formation of the scan area 230-2 is shown after the second scan is performed using the exposure unit 210. More specifically, after the first scan is performed using the exposure unit 210, the stage moves the substrate in the negative Y direction to align the exposure unit 210 with the next designated area, and then the stage moves the substrate in the negative X direction under the exposure unit 210 to form the scan area 230-2.

[0039] Figure 2DThe formation of the scan area 230-3 is shown after the third scan is performed using the exposure unit 210. More specifically, after the second scan is performed using the exposure unit 210, the stage moves the substrate in the positive Y direction to align the exposure unit 210 with the next designated area, and then the stage moves the substrate in the positive X direction under the exposure unit 210 to form the scan area 230-3. By forming the scan areas 230-4, 230-5, and 230-6, additional scans (such as the fourth, fifth, and sixth scans) can be performed to complete the scan.

[0040] During the scanning process described above, one or more "mura" issues may be observed. Mura is a Japanese term that generally refers to any visible variation across a display that occurs as a result of the scanning process.

[0041] One example of clouding is "scan clouding," which occurs after each scan. For example, one type of scan clouding is illumination non-uniformity, 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 pattern size. Another example of clouding is "vibration clouding," where vibrations caused by operating a digital lithography system can cause the exposure unit to vibrate, resulting in unstable scans. Because the exposure unit vibrations may not be spatially synchronized, this can result in visible variations across the display.

[0042] Another example of clouding is "boundary clouding," where an abrupt change in appearance can be observed at the boundary or edge of an area scanned by one exposure unit and an adjacent area scanned by another exposure unit. For example, boundary clouding can occur at the boundary between areas scanned by a pair of adjacent exposure units for a given bridge (e.g., at Figure 1 As another example, boundary cloud may appear at a boundary between areas scanned by a pair of adjacent exposure units corresponding to different bridges (e.g., at a boundary between the scanning areas 112-2 and 112-4). Figure 1 appears at the boundary between the scanning areas 112-1 and 112-2).

[0043] There can be a variety of different microscopic and / or macroscopic causes of boundary clouding. For example, if one exposure unit is outputting more light during a scan than an adjacent exposure unit, a sudden change in the line width of the printed line can be observed across the boundary between exposure units. As another example, if one exposure unit is out of focus compared to the other exposure units, the photoresist sidewall profile corresponding to each exposure unit can be different. For example, an exposure unit with better focus can have more vertical sidewalls compared to the more inclined sidewalls of an exposure unit with poorer focus. Thus, problems can exist at the boundary of adjacent scan areas.

[0044] As will be described in further detail herein, clouds (e.g., boundary clouds) can be detected by performing the scan ordering described herein (such as described above with respect to Figures 2A to 2D The sequence described from outside to inside or the following about Figures 3A to 3D The inside-out sequence described herein can be used to address this issue by reducing delays between scans of stitched regions at the edges of the scanned regions. For example, the digital lithography sequencing described herein can be performed to produce smooth transitions between regions scanned by different exposure units (e.g., maintaining critical dimensions across regions).

[0045] In some embodiments, performing sequencing as described herein includes performing dose blending, where dose refers to the amount of radiation or light to which an area is exposed. For dose blending, the intensity of a light source can be adjusted during scanning of one or more portions of an area associated with an exposure unit. Alternatively or additionally, the number of passes applied to different portions of the area associated with an exposure unit can be varied to provide different exposure levels by the exposure units. For example, a first exposure unit may apply 100% of a target light intensity to achieve a full dose for the majority of the area covered by the first exposure unit. However, for a portion of the area covered by the first exposure unit (such as a tiled area), the first exposure unit may apply 50% of the target light intensity to provide half the dose. A second exposure unit may span into the area covered by the first exposure unit (e.g., the tiled area) and apply 50% of the target light intensity to that portion of the area that received 50% of the dose from the first exposure unit. Thus, the doses or exposures of the two exposure units are effectively "blended" for that portion of the area, such that it receives a partial dose from one exposure unit and a partial dose from the other exposure unit. Dose blending can be achieved by performing "local multiple passes" at the boundaries of corresponding scan areas. More specifically, multiple passes of the scan may be performed around the boundary to achieve a dose mixing effect.

[0046] Figures 3A to 3D300A-300D are top-down views of a scanning path from inside to outside of a substrate's scanning area 320 through a single digital lithography exposure unit ("exposure unit") 310 of a digital lithography system according to some embodiments. The exposure unit 310 may be, for example, the one described above with reference to FIG. Figure 1 The exposure unit 120-1 of the digital lithography system 100 is depicted. The substrate is disposed on a platform (not shown). In some embodiments, the first designated area to be scanned (e.g., a first sub-area of ​​the scanning area 320) may be located near the horizontal centerline (e.g., the centerline in the X direction) of the scanning area 320.

[0047] Figure 3A The formation of scan area 330-1 within scan area 320 is shown after a first scan is performed using exposure unit 310. More specifically, the stage moves the substrate in the positive X direction beneath exposure unit 310 to form scan area 330-1. Before performing the first scan, edge 322 of scan area 320 may be aligned with edge 312 of exposure unit 310. The stage moves the substrate in the XY directions according to a digital lithography scanning procedure, thereby performing multiple scans across scan area 320. The amount of time that exposure unit 310 spends scanning scan area 330-1 may be referred to as a scan duration.

[0048] Figure 3B The formation of the scan area 330-2 is shown after the second scan is performed using the exposure unit 310. More specifically, after the first scan is performed using the exposure unit 310, the stage moves the substrate in the positive Y direction to align the exposure unit 310 with the next designated area, and then the stage moves the substrate in the negative X direction under the exposure unit 310 to form the scan area 330-2.

[0049] Figure 3C The formation of the scan area 330-3 is shown after the third scan is performed using the exposure unit 310. More specifically, after the second scan is performed using the exposure unit 310, the stage moves the substrate in the negative Y direction to align the exposure unit 310 with the next designated area, and then the stage moves the substrate in the positive X direction under the exposure unit 310 to form the scan area 330-3.

[0050] Figure 3DThe formation of additional scan areas 330-4, 330-5, and 330-6 is shown after performing the fourth, fifth, and sixth scans using exposure unit 310. More specifically, the stage moves the substrate back and forth in the Y direction to align exposure unit 310 with the next designated area. The stage moves the substrate back and forth in the X direction to form additional scan areas. In some embodiments, scan areas 330-5 and 330-6 correspond to stitching areas associated with scan area 320 and adjacent scan areas.

[0051] Figures 4A to 4C Figures 400A-400C illustrate an example of digital lithography exposure unit ("exposure unit") boundary smoothing, according to some embodiments. Exposure unit boundary smoothing can be achieved by performing exposure unit boundary shifting and / or dose blending. For example, Figures 400A-400C can each correspond to a cropping layer defining the boundary of an exposure unit.

[0052] exist Figure 4A 4, the diagram 400A illustrates a first scanning area 410-A corresponding to a first exposure unit and a second scanning area 420-A corresponding to a second exposure unit separated by a boundary 415. The first and second exposure units may be adjacent exposure units attached to the same bridge. For example, the first exposure unit may correspond to Figure 1 The exposure unit 1, and the second exposure unit may correspond to Figure 1 Alternatively, the first and second exposure units may be adjacent exposure units attached to different bridges. For example, the first exposure unit may correspond to Figure 1 The exposure unit 1, and the second exposure unit may correspond to Figure 1 The exposure unit 12 is provided.

[0053] In this example, there is no exposure unit boundary smoothing between first scan area 410-A and second scan area 420-A. More specifically, the first exposure unit is 100% responsible for scanning in first scan area 410-A up to boundary 415, and then the second exposure unit is 100% responsible for scanning in second scan area 420-A up to boundary 415. In other words, first scan area 410-A receives 100% of the dose from the first exposure unit, and second scan area 420-A receives 100% of the dose from the second exposure unit.

[0054] exist Figure 4B, diagram 400B illustrates a first scan area 410-B corresponding to a first exposure unit and a second scan area 420-B corresponding to a second exposure unit. Here, the smoothing of the exposure unit boundary between the first scan area 410-B and the second scan area 420-B has resulted in aliasing. More specifically, the first exposure unit is programmed to extend to the original scan area corresponding to the second exposure unit (e.g., Figure 4A The second exposure unit is programmed to extend to the original scanning area corresponding to the first exposure unit (eg, Figure 4A The sawtooth is blended in the scanning area 410-A). Figure 4B The vertical boundaries 430-1 to 430-4 and the horizontal boundaries 435-1 to 435-3 are shown in FIG. The boundaries 430-1 to 430-4 and 435-1 to 435-1 may not be visible and are provided for illustration. Figure 3B The exposure unit boundaries are shown smoothed. A mixed dose region is defined between vertical boundary 430-1 and vertical boundary 430-4. With respect to the region defined by horizontal boundary 435-1, the first exposure unit provides 75% of the dose and the second exposure unit provides 25% of the dose. With respect to the region defined by horizontal boundary 335-2, both the first and second exposure units provide 50% of the dose. With respect to the region defined by horizontal boundary 335-3, the first exposure unit provides 25% of the dose and the second exposure unit provides 75% of the dose.

[0055] Figure 4B The boundary smoothing shown can be achieved by performing exposure cell boundary shifting and / or dose blending. With respect to exposure cell boundary shifting, multiple passes can be performed to obtain a sawtooth blend. In this illustrative example, four passes can be performed, wherein the exposure cell boundary is shifted after each pass (i.e., 4 passes of boundary shifting). For example, in the single bridge case, the exposure cell boundary can be shifted vertically (e.g., by vertically shifting the clipping layer), and in the double bridge case, the exposure cell boundary can be shifted horizontally (e.g., by horizontally shifting the clipping layer). With respect to dose blending, when a single pass is performed, a "local multiple pass" can be performed around the original boundary 415 to provide a specified amount of dose to each of the exposure cells. In this illustrative example, the first and second exposure cells can each provide 4 dose amounts (100%, 75%, 50% and 25%) to achieve Figure 4B The exposure unit boundaries are shown to be smooth.

[0056] exist Figure 4C, diagram 400C illustrates first exposure cell region 410-C and second exposure cell region 420-C with gradual blending corresponding to diagonal boundary 440. In some embodiments, the horizontal distance covered by boundary 440 corresponds to the stitching region between first exposure cell region 410-C and second exposure cell region 420-C. Achieving gradual blending of diagonal boundary 440 is a theoretical ideal for boundary smoothing at the stitching region, as it can be achieved after a suitable number of passes (e.g., an infinite number of passes) during exposure cell boundary shifting and / or after a suitably fine (e.g., infinitesimally fine) dose blending around the boundary of each exposure cell during dose blending.

[0057] Figure 5 FIG500 is a diagram of an example scanning configuration 520 of digital lithography exposure units in a single-bridge embodiment, according to some embodiments. Scanning configuration 520 illustrates an example stitching region 524 for a first scanning area 521 and a second scanning area 522. In some embodiments, stitching region 524 is located at the interface between first scanning area 521 and second scanning area 522. For example, first scanning area 521 may be associated with a first exposure unit, while second scanning area 522 may be associated with a second exposure unit. The exposure unit boundaries of the first and second exposure units may overlap, and the overlapping region may correspond to stitching region 524.

[0058] In some embodiments, the first exposure unit performs a scan of the stitching area 524 while the second exposure unit performs a scan of a sub-area of ​​the second scanning area 522. Thereafter, the second exposure unit performs a scan of the stitching area while the first exposure unit performs a scan of a sub-area of ​​the first scanning area. In some embodiments, the first exposure unit and the second exposure unit each perform a scan of the stitching area 524 using a partial dose, so that during both scans, the stitching area 524 receives 100% of the dose. For example, the first exposure unit may scan the stitching area 524 at 50% of the dose, and the second exposure unit may subsequently scan the stitching area 524 at another 50%. In some embodiments, with respect to Figures 4A to 4C One or more of the described boundary smoothing techniques are performed by the first and second exposure units with respect to the stitched area 524. In some embodiments, the second scan of the stitched area 524 is performed within a threshold amount of time after the first scan of the stitched area 524, as described below with respect to Figures 6A to 6B described.

[0059] Figures 6A to 6B is a diagram of an example scanning sequence of a digital lithography exposure unit with respect to time, according to some embodiments. Figure 6A is a diagram of an outside-in scanning sequence 600A of a digital lithography exposure unit with respect to time, according to some embodiments. Figure 6Bis a diagram of an inside-out scanning sequence 600B of a digital lithography exposure unit with respect to time, according to some embodiments.

[0060] In some embodiments, a stitching area 624 is associated with the first scanning area 621 and the second scanning area 622. The stitching area 624 may correspond to a boundary area between the first scanning area 621 and the second scanning area 622. In some embodiments, a first exposure unit of a digital lithography system may have a boundary area including the first scanning area 621 and the stitching area 624. A second exposure unit may have a boundary area including the second scanning area 622 and the stitching area 624. The first and second exposure units may be attached to the same bridge unit. Thus, the first and second exposure units can move together relative to the substrate (i.e., the first scanning area 621, the second scanning area 622, and the stitching area 624).

[0061] See also Figure 6A , illustrates an outside-in scanning sequence 600A. For purposes of illustration and description, the outside-in scanning sequence 600A includes four distinct time intervals for performing scanning operations. However, the sequence 600A is not limited to four distinct time intervals. In some embodiments, the outside-in scanning sequence 600A includes more distinct time intervals for performing scanning operations. In some embodiments, during time interval 612-1, a first exposure unit (not shown) scans a first sub-region 614-1A of a first scanning area 621. Simultaneously, a second exposure unit (not shown) scans a first sub-region 614-1B of a second scanning area 622 corresponding to a stitched area 624. In some embodiments, the second exposure unit scans the first sub-region 614-1B corresponding to the stitched area 624 using a partial dose of radiation. The first exposure unit may scan the first sub-region 614-1A using a full dose of radiation. Sub-regions 614-1A and 614-1B may be "outer" sub-regions. In some embodiments, the first sub-region 614-1A is adjacent to an outer edge of the first scanning area 621. Since the stitching area 624 is located at the boundary between the first scanning area 621 and the second scanning area 622, the sub-area 614-1B is adjacent to the outer edge of the second scanning area 622. After the time interval 612-1 expires, the stage on which the substrate is placed moves in the Y direction to align the first and second exposure units with the next sub-area to be scanned.

[0062] During time interval 612-2, the first exposure unit scans second sub-area 614-2A of first scanning area 621, while the second exposure unit scans second sub-area 614-2B of second scanning area 622. In some embodiments, the first exposure unit scans second sub-area 614-2A corresponding to stitched area 624 using a partial dose of radiation. The second exposure unit may scan second sub-area 614-2B using a full dose of radiation. In some embodiments, second sub-area 614-2A is located near the outer edge of first scanning area 621, and second sub-area 614-2B is located near the outer edge of second scanning area 622. In some embodiments, second sub-areas 614-2A and 614-2B are located near the edges opposite the corresponding first sub-areas 614-1A and 614-1B. Sub-areas 614-2A and 614-2B may be "outer" sub-areas. After time interval 612-2 expires, the stage moves in the Y direction to align the first and second exposure units with the next sub-area to be scanned.

[0063] During time interval 612-3, the first exposure unit scans the third sub-region 614-3A of the first scanning area 621, while the second exposure unit scans the third sub-region 614-3B of the second scanning area 622. Third sub-region 614-3A may be adjacent to first sub-region 614-1A, and third sub-region 614-3B may be adjacent to first sub-region 614-1B. Third sub-region 614-3A may be closer to the horizontal centerline of the first scanning area 621 than first sub-region 614-1A, and third sub-region 614-3B may be closer to the horizontal centerline of the second scanning area 622 than first sub-region 614-1B. In some embodiments, third sub-regions 614-3A and 614-3B are "interior" sub-regions. After time interval 612-3 expires, the stage moves in the Y direction to align the first and second exposure units with the next sub-region to be scanned.

[0064] During time interval 612-4, the first exposure unit scans fourth sub-region 614-4A of first scanning area 621, while the second exposure unit scans fourth sub-region 614-4B of second scanning area 622. Fourth sub-region 614-4A may be adjacent to second sub-region 6142-A, and fourth sub-region 614-4B may be adjacent to second sub-region 614-2B. Fourth sub-region 614-4A may be closer to the horizontal centerline of first scanning area 621 than second sub-region 614-2A, and fourth sub-region 614-4B may be closer to the horizontal centerline of second scanning area 622 than second sub-region 614-2B. In some embodiments, fourth sub-regions 614-4A and 614-4B are "inner" sub-regions. In some embodiments, according to scanning sequence 600A, outer sub-regions are scanned before inner sub-regions. After the time interval 612-4 expires, all of the first scanning area 621 and the second scanning area 622 may be scanned, and one or more scanning features generated by the scanning may be formed. Each of the time intervals 612-1, 612-2, 612-3, and / or 612-4 may be a scanning duration.

[0065] See also Figure 6B , illustrating an inside-out scanning sequence. For purposes of illustration and description, inside-out scanning sequence 600B includes four different time intervals for performing scanning operations. However, sequence 600B is not limited to four time intervals. In some embodiments, inside-out scanning sequence 600B includes more different time intervals for performing scanning operations. In some embodiments, during time interval 612-1, the first exposure unit scans a first sub-region 614-1A of a first scanning area 621, and the second exposure unit scans a first sub-region 614-1B of a second scanning area 622. The first sub-regions 614-1A and 614-1B may be "inside" sub-regions of the respective first scanning area 621 and second scanning area 622. In some embodiments, the first sub-region 614-1A is located near the horizontal centerline of the first scanning area 621, and the first sub-region 614-1B is located near the horizontal centerline of the second scanning area 622. After the time interval 612-1 expires, the stage moves in the Y direction to align the first and second exposure units with the next sub-region to be scanned.

[0066] In some embodiments, during the duration of time interval 612-2, the first exposure unit scans the second sub-region 614-2A of the first scanning area 621, while the second exposure unit scans the second sub-region 614-2B of the second scanning area 622. The second sub-regions 614-2A and 614-2B may be "inner" sub-regions of the respective first scanning area 621 and second scanning area 622. In some embodiments, the second sub-region 614-2A is located near the horizontal centerline of the first scanning area 621, opposite the centerline of the first sub-region 614-1A. In some embodiments, the second sub-region 614-2B is located near the horizontal centerline of the second scanning area 622, opposite the centerline of the first sub-region 614-1B. After the expiration of time interval 612-2, the stage moves in the Y direction to align the first and second exposure units with the next sub-region to be scanned.

[0067] In some embodiments, during time interval 612-3, the first exposure unit scans the third sub-region 614-3A of the first scanning area 621, while the second exposure unit scans the third sub-region 614-3B of the second scanning area 622. The third sub-regions 614-3A and 614-3B may be "outer" sub-regions of the respective first and second scanning areas 621 and 622. In some embodiments, the third sub-region 614-3A is adjacent to the outer edge of the first scanning area 621. The third sub-region 614-3A may correspond to the stitching area 624. In some embodiments, the third sub-region 614-3B is adjacent to the outer edge of the second scanning area 622. In some embodiments, the first exposure unit scans the third sub-region 614-3A corresponding to the stitching area 624 using a partial dose of radiation. The second exposure unit may scan the third sub-region 614-3B using a full dose of radiation. After time interval 612-3 expires, the stage moves in the Y direction to align the first and second exposure units with the next sub-region to be scanned.

[0068] In some embodiments, during time interval 612-4, the first exposure unit scans the fourth sub-region 614-4A of the first scanning area 621, while the second exposure unit scans the fourth sub-region 614-4B of the second scanning area 622. Fourth sub-regions 614-4A and 614-4B may be "outer" sub-regions of the respective first scanning area 621 and second scanning area 622. In some embodiments, according to scanning sequence 600B, inner sub-regions are scanned before outer sub-regions. After time interval 612-4 expires, all of the first scanning area 621 and the second scanning area 622 may be scanned, and one or more scan features generated by the scanning may be formed.

[0069] In some embodiments, each of time intervals 612-1, 612-2, 612-3, and 612-4 is of a predetermined length of time. In some embodiments, the duration of each time interval is less than 40 seconds. In some embodiments, each time interval has a duration between 1 and 20 seconds. In some embodiments, each time interval has a duration of approximately 3 seconds. In some embodiments, each time interval has a duration of approximately 8 seconds. In some embodiments, the scanning operation performed on the stitched area 624 (e.g., a first scan performed by the first exposure unit and a second scan performed by the second exposure unit) occurs at a time that varies less than 40 seconds. In some embodiments, the scanning operation performed on the stitched area 624 occurs at a time that varies between 1 and 20 seconds. In some embodiments, the scanning operation performed on the stitched area 624 occurs at a time that varies less than 8 seconds. In some embodiments, the scanning operation performed on the stitched area 624 occurs at a time that varies less than 3 seconds.

[0070] Figure 7 700A illustrates a feature formed on a substrate using a digital lithography process, according to some embodiments. FIG. 700B illustrates a scanned feature formed on a substrate using scan sequencing, wherein a significant time delay exists between the first and second scans on a tiled region 724. FIG. 700B illustrates a scanned feature formed on a substrate using the digital lithography scan sequencing described herein, wherein a time delay exists between the first and second scans on the tiled region 724 that is less than a threshold time amount. As shown in FIG. 700A , if a scan operation is performed on the tiled region 724 with a delay greater than the threshold time amount, an anomaly 726 in the feature formed by the scan may occur. Such an anomaly 726 may include a defect requiring the scanned substrate to be scrapped. As shown in FIG. 700B , if a scan operation is performed on the tiled region 724 with a delay less than the threshold time amount, the anomaly may not occur due to the delay between scans. In some embodiments, the threshold time amount is approximately 40 seconds. In some embodiments, the threshold time amount is approximately 20 seconds. In some embodiments, the threshold time amount is approximately 8 seconds. In some embodiments, the threshold time amount is approximately 3 seconds. By using an inside-out scanning sequence or an outside-in scanning sequence with respect to the first scanning area 721 and the second scanning area 722, the delay between the first scan of the tiled area using the first exposure unit and the second scan of the tiled area using the second exposure unit can be reduced. By reducing the delay between scans performed on the tiled area 724, fewer defects are formed in the substrate, resulting in increased process output.

[0071] Figure 8A flow chart is depicted of a method 800 for implementing digital lithography scan sequencing according to some embodiments. The method may be performed by processing logic that may include hardware (circuitry, dedicated logic, etc.), computer-readable instructions (run on a general-purpose computer system or a dedicated machine), or a combination of both. In the illustrative example, the method 800 may be performed by a processing device of a digital lithography system. It should be noted that Figure 8 The blocks depicted in the figures may be executed concurrently or in a different order than depicted.

[0072] At block 810, processing logic receives an instruction to execute a digital photolithography process to pattern a substrate. At block 820, processing logic initiates the digital photolithography process to pattern the substrate according to the instructions. The substrate can be positioned on a platform, and the platform can be moved in the XY direction beneath a digital photolithography exposure unit ("exposure unit") according to the instructions. For example, the instructions can be executed to implement scan sequencing as described above. In some embodiments, the digital photolithography process is a multi-pass process, comprising a plurality of passes that scan two or more adjacent scan areas.

[0073] At block 830, processing logic performs a first pass of the first exposure unit over the tiled area at a first time. The tiled area may be at the interface of a first scanning area corresponding to the first exposure unit and a second scanning area corresponding to the second exposure unit. In some embodiments, the first exposure unit provides a partial dose of radiation to the tiled area. For example, the first exposure unit may provide 50% of the total radiation dose to the tiled area during the first pass. While the first exposure unit performs the first pass over the tiled area, the second exposure unit may perform a pass over a sub-area of ​​the second scanning area associated with the second exposure unit.

[0074] At block 840, processing logic performs a second pass of the second exposure unit over the tiled area at a second time. In some embodiments, the second time differs from the first time by less than approximately 40 seconds. In some embodiments, the second time differs from the first time by less than approximately 20 seconds, less than approximately 8 seconds, or less than approximately 3 seconds. In some embodiments, the second exposure unit provides a partial dose of radiation to the tiled area. For example, the second exposure unit may provide 50% of the total radiation dose to the tiled area during the first pass. In some embodiments, the first exposure unit contributes a first percentage of radiation to the tiled area during the first pass, and the second exposure unit contributes a second percentage of radiation to the tiled area during the second pass. The sum of the first and second percentages equals 100%. When the second exposure unit performs the second pass over the tiled area, the first exposure unit may perform a pass over a sub-area of ​​the first scanning area associated with the first exposure unit.

[0075] In some embodiments, the first pass and / or the second pass occur at the beginning or end of a multi-pass digital lithography process. Figure 6A The outside-in scanning sequence described in this article or Figure 6B In some embodiments, the second pass of the second exposure unit over the tiled area occurs after the first pass of the first exposure unit over the tiled area.

[0076] Figure 9 is a block diagram illustrating a digital lithography system ("system") 900, according to some embodiments. As shown, system 900 includes a digital lithography exposure unit ("exposure unit") 910, a platform 920, and a processing device 930. Processing device 930 includes a processor 932 operatively coupled to a memory 934. The memory may maintain instructions 936 for executing digital lithography within system 900. For example, instructions 926 may include instructions for controlling the movement of platform 920 and / or exposure unit 910. When executed, the instructions may implement the method for performing exposure unit scan sequencing described herein above.

[0077] Figure 10 is a block diagram illustrating a computer system 1000 according to certain embodiments. In some embodiments, the computer system 1000 is connected (e.g., via a network, such as a local area network (LAN), an intranet, an extranet, or the Internet) to other computer systems. In some embodiments, the computer system 1000 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, the computer system 1000 is provided by a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a cellular phone, a network appliance, a server, a network router, a switch or a bridge, or any device capable of executing a set of instructions (serial or otherwise) that specify actions to be taken by that device. Additionally, the term "computer" shall include any collection of computers that, individually or in combination, execute an instruction set (or multiple instruction sets) to perform any one or more of the methods described herein.

[0078] In another aspect, the computer system 1000 includes a processing device 1002, a volatile memory 1004 (e.g., random access memory (RAM)), a non-volatile memory 1006 (e.g., read-only memory (ROM) or electrically erasable programmable ROM (EEPROM)), and a data storage device 1016 that communicate with each other via a bus 1008.

[0079] In some embodiments, the processing device 1002 is provided by one or more processors, such as a general-purpose processor (such as, for example, a Complex Instruction Set Computing (CISC) microprocessor, a Reduced Instruction Set Computing (RISC) microprocessor, a Very Long Instruction Word (VLIW) microprocessor, a microprocessor that implements other types of instruction sets, or a microprocessor that implements a combination of types of instruction sets) or a special-purpose processor (such as, for example, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Digital Signal Processor (DSP), or a network processor).

[0080] In some embodiments, the computer system 1000 further includes a network interface device 1022 (e.g., coupled to the network 1074). In some embodiments, the computer system 1000 also includes a video display unit 1010 (e.g., an LCD), an alphanumeric input device 1012 (e.g., a keyboard), a cursor control device 1014 (e.g., a mouse), and a signal generating device 1020.

[0081] In some embodiments, the data storage device 1016 includes a non-transitory computer-readable storage medium 1024 having stored thereon instructions 1026 encoding any one or more of the methods or functions described herein. For example, the instructions 1026 may include instructions for controlling the movement of a platform and / or a digital lithography exposure unit ("exposure unit") of a digital lithography system, which, when executed, may implement the methods for performing the exposure unit scan sequencing described herein.

[0082] In some embodiments, the instructions 1026 are also completely or partially stored within the volatile memory 1004 and / or the processing device 1002 during execution thereof by the computer system 1000. Thus, in some embodiments, the volatile memory 1004 and the processing device 1002 also constitute machine-readable storage media.

[0083] Although the computer-readable storage medium 1024 is shown as a single medium in the illustrative example, the term "computer-readable storage medium" shall 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 executable instruction sets. The term "computer-readable storage medium" shall also include any tangible medium that can store or encode an instruction set for execution by a computer, the instruction set causing the computer to perform any one or more of the methods described herein. The term "computer-readable storage medium" shall include, but is not limited to, solid-state memory, optical media, and magnetic media.

[0084] In some embodiments, the methods, components, and features described herein are implemented by discrete hardware components or integrated into the functionality of other hardware components (such as ASICs, FPGAs, DSPs, or similar devices). In some embodiments, the methods, components, and features are implemented by firmware modules or functional circuits within hardware devices. In some embodiments, the methods, components, and features are implemented in any combination of hardware devices and computer program components, or in a computer program.

[0085] Unless otherwise specifically stated, terms such as "train," "identify," "further train," "retrain," "cause," "receive," "provide," "obtain," "optimize," "determine," "update," "initialize," "generate," "add," or the like refer to actions and processes performed or implemented by a computer system to manipulate and transform data represented as physical (electronic) quantities in a computer system's buffers and memory into other data similarly represented as physical quantities within the computer system's memory or buffers or other such information storage, transmission, or display devices. In some embodiments, as used herein, the terms "first," "second," "third," "fourth," etc., are meant to distinguish among different elements and do not have an ordinal meaning based on their numerical designations.

[0086] The examples described herein also relate to an apparatus for performing the methods described herein. In some embodiments, the apparatus is specially constructed to perform the methods described herein, or comprises a general-purpose computer system selectively programmed by a computer program stored in the computer system. The computer program is stored in a computer-readable tangible storage medium.

[0087] 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 according to the teachings described herein. In some embodiments, more specialized devices are constructed to perform the methods described herein and / or each of their individual functions, routines, subroutines, or operations. Examples of structures for various such systems are set forth in the description above.

[0088] The foregoing description sets forth several specific details, such as examples of specific systems, components, methods, etc., in order to provide a good understanding of several embodiments of the present invention. However, it will be apparent to those skilled in the art that at least some embodiments of the present invention can be practiced without such specific details. In other examples, well-known components or methods are not described in detail and are provided in a simple block diagram format to avoid unnecessary obfuscation of the present invention. Therefore, the specific details set forth are merely exemplary. Specific embodiments may vary from these exemplary details and are still contemplated within the scope of the present invention.

[0089] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the term "or" is intended to mean an inclusive or rather than an exclusive or. When the term "about" or "approximately" is used herein, it is intended to mean that the nominal value provided is accurate to within ±10%.

[0090] Although the operations of the methods herein are illustrated and described in a particular order, the order of the operations of each method may be modified such that certain operations may be performed in reverse order, or such that certain operations may be performed at least partially concurrently with other operations. In another embodiment, instructions or sub-operations of different operations may be performed intermittently and / or in alternating fashion.

[0091] It will be understood that the above description is intended to be illustrative and not restrictive. Many other implementation examples will become apparent to those skilled in the art upon reading and understanding the above description. Although this disclosure describes specific examples, it will be appreciated that the systems and methods of the present disclosure are not limited to the examples described herein, but may be practiced with modifications within the scope of the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative and not a restrictive sense. Accordingly, the scope of the present disclosure should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. A digital lithography system, comprising: a plurality of scanning areas, the plurality of scanning areas comprising a first scanning area and a second scanning area adjacent to the first scanning area; a plurality of exposure units positioned over the plurality of scanning areas, the plurality of exposure units including a first exposure unit associated with the first scanning area and a second exposure unit associated with the second scanning area; Memory; as well as at least one processing device operatively coupled to the memory, the at least one processing device configured to: initiating a digital lithography process to pattern a substrate disposed on a platform according to the instructions; performing a first pass of the first exposure unit over a stitching area at an interface of the first scanning area and the second scanning area at a first time; and A second pass of the second exposure unit over the stitching area is performed at a second time that is less than forty seconds different from the first time.

2. A digital lithography system as described in claim 1, wherein the digital lithography process is a multi-pass process comprising multiple passes, and wherein performing the digital lithography process comprises performing the second pass after the first pass at the beginning of the multi-pass process or at the end of the multi-pass process.

3. The digital lithography system of claim 1 , wherein the first exposure unit and the second exposure unit are attached to the same bridge of the digital lithography system, and wherein to perform the digital lithography process, the at least one processing device is configured to: scanning a first sub-area of ​​the second scanning area using the second exposure unit while performing the first pass using the first exposure unit; and A second sub-area of ​​the first scanning area is scanned using the first exposure unit while the second pass is performed using the first exposure unit.

4. The digital lithography system of claim 1 , wherein the digital lithography process comprises: scanning a first sub-area of ​​a corresponding scanning area among the plurality of scanning areas that is close to a first edge of the corresponding scanning area; Thereafter, scanning a second sub-region of the corresponding scanning region adjacent to a second edge of the corresponding scanning region opposite to the first edge, wherein the first sub-region or the second sub-region includes the stitching region; and Thereafter, a third sub-region of the corresponding scanning region that is opposite to the first edge and close to the first sub-region is scanned.

5. The digital lithography system of claim 1 , wherein the digital lithography process comprises: Scanning a first sub-area of ​​a corresponding scanning area close to a center line of the corresponding scanning area among the plurality of scanning areas; Thereafter, scanning a second sub-area of ​​the corresponding scanning area close to the first sub-area toward a first edge of the corresponding scanning area; scanning a third sub-area of ​​the corresponding scanning area close to the first edge or the second edge of the corresponding scanning area; and Thereafter, a fourth sub-area of ​​the corresponding scanning area that is opposite to the third sub-area and close to the first edge or the second edge is scanned, wherein the third sub-area or the fourth sub-area includes the stitching area.

6. A digital lithography system as described in claim 1, wherein performing the first pass and performing the second pass include performing dose mixing with respect to the stitching area, and wherein performing the dose mixing includes causing the first exposure unit to contribute a first percentage of the total dose to the stitching area and causing the second exposure unit to contribute a second percentage of the total dose to the stitching area, such that the sum of the first percentage and the second percentage is equal to 100%.

7. The digital lithography system of claim 1, wherein the second time differs from the first time by approximately one scan duration.

8. A system comprising: Memory; as well as at least one processing device operatively coupled to the memory, the at least one processing device configured to: initiating a digital lithography process to pattern the substrate according to the instructions; performing a first pass of the first exposure unit over the stitching area at an interface of a first scanning area of ​​the plurality of scanning areas and a second scanning area of ​​the plurality of scanning areas at a first time; and A second pass of the second exposure unit over the stitching area is performed at a second time that differs from the first time by less than forty seconds.

9. A system as described in claim 8, wherein the digital lithography process is a multi-pass process comprising multiple passes, and wherein performing the digital lithography process comprises performing the second pass after the first pass at the beginning of the multi-pass process or at the end of the multi-pass process.

10. The system of claim 8, wherein the first exposure unit and the second exposure unit are attached to the same bridge of the system, and wherein to perform the digital lithography process, the at least one processing device is configured to: scanning a first sub-area of ​​the second scanning area using the second exposure unit while performing the first pass using the first exposure unit; and A second sub-area of ​​the first scanning area is scanned using the first exposure unit while the second pass is performed using the first exposure unit.

11. The system of claim 8, wherein the digital lithography process comprises: scanning a first sub-area of ​​a corresponding scanning area among the plurality of scanning areas that is close to a first edge of the corresponding scanning area; Thereafter, scanning a second sub-region of the corresponding scanning region adjacent to a second edge of the corresponding scanning region opposite to the first edge, wherein the first sub-region or the second sub-region includes the stitching region; and Thereafter, a third sub-region of the corresponding scanning region that is opposite to the first edge and close to the first sub-region is scanned.

12. The system of claim 8, wherein the digital lithography process comprises: Scanning a first sub-area of ​​a corresponding scanning area close to a center line of the corresponding scanning area among the plurality of scanning areas; Thereafter, scanning a second sub-area of ​​the corresponding scanning area close to the first sub-area toward a first edge of the corresponding scanning area; scanning a third sub-area of ​​the corresponding scanning area close to the first edge or the second edge of the corresponding scanning area; and Thereafter, a fourth sub-area of ​​the corresponding scanning area that is opposite to the third sub-area and close to the first edge or the second edge is scanned, wherein the third sub-area or the fourth sub-area includes the stitching area.

13. The system of claim 8, wherein performing the first pass and performing the second pass comprises performing dose blending with respect to the stitched area, and wherein performing the dose blending comprises causing the first exposure unit to contribute a first percentage of a total dose to the stitched area and causing the second exposure unit to contribute a second percentage of the total dose to the stitched area, such that the sum of the first percentage and the second percentage equals 100%.

14. The system of claim 8, wherein the second time differs from the first time by less than eight seconds.

15. A method comprising: initiating a digital lithography process by a processing device to pattern the substrate according to the instructions; performing a first pass of the first exposure unit over the stitching area at an interface of a first scanning area of ​​the plurality of scanning areas and a second scanning area of ​​the plurality of scanning areas at a first time; and A second pass of the second exposure unit over the stitching area is performed at a second time that differs from the first time by less than forty seconds.

16. A method as claimed in claim 15, wherein the digital lithography process is a multi-pass process comprising multiple passes, and wherein performing the digital lithography process comprises: performing the second pass after the first pass at the beginning of the multi-pass process or at the end of the multi-pass process.

17. The method of claim 15, wherein the first exposure unit and the second exposure unit are attached to the same bridge of a digital lithography system, and wherein the digital lithography process comprises: scanning a first sub-area of ​​the second scanning area by the second exposure unit while performing the first pass by the first exposure unit; and The second sub-area of ​​the first scanning area is scanned by the first exposure unit while the second pass is performed by the first exposure unit.

18. The method of claim 15, wherein the digital lithography process comprises: scanning a first sub-area of ​​a corresponding scanning area among the plurality of scanning areas that is close to a first edge of the corresponding scanning area; Thereafter, scanning a second sub-region of the corresponding scanning region adjacent to a second edge of the corresponding scanning region opposite to the first edge, wherein the first sub-region or the second sub-region includes the stitching region; and Thereafter, a third sub-region of the corresponding scanning region that is opposite to the first edge and close to the first sub-region is scanned.

19. The method of claim 15, wherein the digital lithography process comprises: Scanning a first sub-area of ​​a corresponding scanning area close to a center line of the corresponding scanning area among the plurality of scanning areas; Thereafter, scanning a second sub-area of ​​the corresponding scanning area close to the first sub-area toward a first edge of the corresponding scanning area; scanning a third sub-area of ​​the corresponding scanning area close to the first edge or the second edge of the corresponding scanning area; and Thereafter, a fourth sub-area of ​​the corresponding scanning area that is opposite to the third sub-area and close to the first edge or the second edge is scanned, wherein the third sub-area or the fourth sub-area includes the stitching area.

20. The method of claim 15, wherein performing the first pass and performing the second pass comprises performing dose blending with respect to the stitched area, and wherein performing the dose blending comprises causing the first exposure unit to contribute a first percentage of a total dose to the stitched area and causing the second exposure unit to contribute a second percentage of the total dose to the stitched area, such that the sum of the first percentage and the second percentage equals 100%.

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