Digital Lithography Exposure Unit Boundary Smoothing

Abstract

The digital lithography system includes a scanning region including a first scanning region and a second scanning region adjacent to the first scanning region. The digital lithography system further includes an exposure unit located above the scanning region, a memory, and at least one processing device operably coupled to the memory. The exposure unit includes a first exposure unit associated with the first scanning region and a second exposure unit associated with the second scanning region. The processing device is for performing operations including initiating a digital lithography process for patterning a substrate disposed on a stage according to an instruction, and performing exposure unit boundary smoothing for the first exposure unit and the second exposure unit during the digital lithography process.

Description

[Technical field]

[0001] This disclosure relates generally to electronic device manufacturing. More particularly, this disclosure relates to digital lithography. [Background technology]

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

[0003] In digital lithography, multiple exposure units are used to increase the throughput, with each exposure unit responsible for a portion of the printed area. However, different exposure units generally have slight variations in their characteristics. This can result in visible boundaries between areas printed by different exposure units. In the case of a display device, the visible boundaries are defects that can cause the produced display to be discarded. Summary of the Invention

[0004] The following is a simplified summary of the disclosure to provide a basic understanding of some aspects of the disclosure. This summary is not an extensive overview of the disclosure. It is not intended to identify key or critical elements of the disclosure, nor to delineate the scope or claims of particular implementations of the disclosure. Its sole purpose is to present some concepts of the disclosure in a simplified form as a prelude to the more detailed description that is presented later.

[0005] According to one embodiment, a digital lithography system is provided. The digital lithography system includes a scanning area including a first scanning area and a second scanning area adjacent to the first scanning area. The digital lithography system further includes an exposure unit located above the scanning area, a memory, and at least one processing device operably coupled to the memory. The exposure unit includes 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 for performing operations including initiating a digital lithography process for patterning a substrate disposed on a stage according to an instruction, and performing exposure unit boundary smoothing for the first exposure unit and the second exposure unit during the digital lithography process.

[0006] According to another embodiment, a system is provided that includes a memory and at least one processing device operatively coupled to the memory for performing operations including initiating a digital lithography process for patterning a substrate according to instructions and performing exposure unit boundary smoothing during the digital lithography process for a first exposure unit of the plurality of exposure units and a second exposure unit of the plurality of exposure units, where the first exposure unit corresponds to a first scan area and the second exposure unit corresponds to a second scan area adjacent to the first scan area.

[0007] According to yet another embodiment, a method is provided that includes initiating, by a processing device, a digital lithography process for patterning a substrate according to instructions, and performing, by the processing device, exposure unit boundary smoothing during the digital lithography process for a first exposure unit of the plurality of exposure units and a second exposure unit of the plurality of exposure units, where the first exposure unit corresponds to a first scan area and the second exposure unit corresponds to a second scan area adjacent to the first scan area.

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

[0009] [Figure 1] FIG. 1 is a top-down view of a digital lithography system, according to some embodiments. [Figure 2A-2B] 1 is a top-down view illustrating a scanning path of a substrate through a single digital lithography exposure unit of a digital lithography system according to some embodiments. [Fig. 2C-2D] 1 is a top-down view illustrating a scanning path of a substrate through a single digital lithography exposure unit of a digital lithography system according to some embodiments. [Figure 3A-3C] FIG. 2 illustrates an example of digital lithography exposure unit boundary smoothing, according to some embodiments. [Figure 4] FIG. 2 illustrates an exemplary scanning configuration of a digital lithography exposure unit in one bridge implementation, according to some embodiments. [Diagram 5] FIG. 2 illustrates an exemplary scanning configuration of a digital lithography exposure unit in a two-bridge implementation, according to some embodiments. [Figure 6] FIG. 1 illustrates an example of dose allocation for a digital lithography exposure unit in one bridge implementation, according to some embodiments. [Figure 7] FIG. 2 illustrates an example of dose allocation for a digital lithography exposure unit in a two-bridge implementation, according to some embodiments. [Figure 8A-8B] FIG. 2 illustrates an example of digital lithography exposure unit dose allocation, according to some embodiments. [Figure 8C] FIG. 2 illustrates an example of digital lithography exposure unit dose allocation, according to some embodiments. [Figure 9]1 is a flowchart of a method for implementing digital lithography exposure unit boundary smoothing, according to some embodiments. [Figure 10] FIG. 1 is a block diagram of a digital lithography system, according to some embodiments. [Figure 11] FIG. 1 is a block diagram illustrating a computer system according to some embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Digital lithography can be used to generate patterns (e.g., for digitally aligned etch masks) on a substrate surface without the use of a photomask (e.g., via maskless lithography). Digital lithography techniques (such as, for example, Texas Instruments® programmable light steering technology) enable 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 high precision. Digital lithography is used to directly expose patterns onto a photoresist film without the use of a contact mask (e.g., photomask). This can reduce material costs, improve production rates, and allow for rapid changes of patterns. Direct exposure increases productivity compared to narrow laser beams or masked systems. An advantage of digital lithography is the ability to change lithography patterns from run to run without incurring the cost of generating new photomasks. As an example, digital lithography can be used to perform large area patterning during electronic device manufacturing.

[0011] In digital lithography, multiple digital lithography exposure units ("exposure units") may be used to improve the throughput of a digital lithography tool. A conventional exposure unit may print or expose a rectangular non-overlapping area, or a clipping layer. The clipping layer may act as a filter to inform the layout processing software to keep the pattern printed by a particular exposure unit on the clipping layer associated with that exposure unit. Each of the multiple exposure units may be responsible for a portion of the printing area and a different clipping layer. Different exposure units may have unique characteristics that do not match exactly. This mismatch may result in non-uniformity (e.g., non-uniformity, inconsistency, irregularity) at the exposure unit boundaries. This non-uniformity may reduce yield and therefore value.

[0012] Aspects and implementations of the present disclosure address these and other shortcomings of existing techniques by performing exposure unit boundary smoothing for at least one pair of digital lithography exposure units ("exposure units"). Exposure unit boundary smoothing can blend exposure unit boundaries to reduce non-uniformity and to eliminate linear boundaries between clipping layers of adjacent exposure units. Blending can result in a gradual transition between pairs of exposure units. Several methods can be utilized to perform exposure unit boundary smoothing according to implementations described herein. Exposure unit boundary smoothing can be performed for one-bridge cases (e.g., to smooth boundaries between adjacent scan regions corresponding to exposure units attached to the same bridge), two-bridge cases (e.g., to smooth boundaries between adjacent scan regions corresponding to exposure units attached to different bridges), etc.

[0013] In some embodiments, performing exposure unit boundary smoothing includes performing exposure unit boundary shifting. More specifically, during exposure unit boundary shifting, the exposure unit boundaries may be shifted for each pass. Shifting the exposure unit boundaries for each pass can work particularly well for multi-pass printing.

[0014] In some embodiments, performing exposure unit boundary smoothing includes performing dose mixing. For example, the dose mixing can include performing staircase blending. As another example, the dose mixing can include progressive blending, and the dose mixing can provide an improved tradeoff between blending and takt time (i.e., the amount of time between the start of production of a first unit and the start of production of a second unit).

[0015] Aspects and implementations of the present disclosure provide technical advantages over other approaches. For example, as described above, non-uniformity at the boundary of adjacent pairs of exposure units and / or at the boundary of pairs of scans associated with a given exposure unit may be reduced. Thus, improved photolithography for patterning a substrate may be achieved.

[0016] FIG. 1 is a top-down view of a digital lithography system ("system") 100, according to some embodiments. As shown, the apparatus 100 includes a stage assembly 110 including a base (e.g., a granite base), a stage, and a substrate disposed on the stage. The substrate may be a glass plate, a wafer, a PCB, or other type of substrate. The substrate may correspond to or be disposed in a digital lithography printing or scanning area having several scanning areas including scanning areas 112-1 through 112-4. A left portion of the stage assembly 110 corresponds to a first bridge 114-1 above the stage assembly 110, and a right portion of the stage assembly 110 corresponds to a second bridge 114-2 above the stage assembly 110. As described in more detail below, exposure units are attached to the bridges 114-1 and 114-2. In some embodiments, the length of each bridge 114-1 and 114-2 may range between about 500 (millimeters) mm and about 1000 mm. For example, the length of each bridge 114-1 and 114-2 may be about 750 mm.

[0017] The substrate may include a photoresist material disposed on the material to be etched. The photoresist material may be a positive photoresist material (i.e., a portion of the photoresist material exposed to light becomes soluble to the photoresist developer) or a negative photoresist material (i.e., a portion of the photoresist material exposed to light becomes insoluble to the photoresist developer). Thus, a photoresist pattern may 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, the conductive material may be molybdenum. After the designated areas of the photoresist material are removed, the next exposed material may be etched according to the photoresist pattern. For example, wiring may be formed during the etching process. Alternatively, the patterned material may itself be photosensitive, eliminating the need for an additional photoresist layer to perform a subsequent etching process.

[0018] To perform photoresist patterning, the apparatus 100 further includes a first row of digital lithography exposure units ("exposure units") spanning from the first bridge 114-1 and a second row of exposure units spanning from the second bridge 114-2. For example, the first row of exposure units includes exposure units 1-11 and the second row of exposure units includes exposure units 12-22. Thus, in this illustrative example, a total of 22 exposure units are shown. However, the number of exposure units shown in FIG. 1 should not be considered limiting and the system 100 can include any suitable number of exposure units in accordance with embodiments described herein.

[0019] Each exposure unit can include a lens assembly capable of projecting an image onto the photoresist material of the substrate. Each lens assembly is shown adjacent the lower right corner of its associated scan area. For example, lens assembly 120 of exposure unit 1 is associated with scan area 112-1. In some embodiments, each lens assembly is about 4 mm high and about 3 mm wide. However, each lens assembly can have any suitable dimensions in accordance with embodiments described herein.

[0020] During the digital lithography process, each exposure unit is moved relative to the substrate to expose an area (e.g., a rectangular area) of the substrate to electromagnetic radiation such as light (e.g., ultraviolet light, near-ultraviolet light, etc.). During scanning, the exposure units expose their respective scan areas according to a programmed scan path. Instead of moving the exposure units above the stage assembly 110, the stage assembly 110 can move in the XY direction below the exposure units according to the programmed scan path. Because the field of view of a lens assembly (e.g., lens assembly 120) may be smaller than its associated scan area (e.g., scan area 112-1), the stage assembly 110 may need to move back and forth repeatedly until the entire scan area (e.g., scan area 112-1) is printed. The lens assembly 120 is projected to scan the scan area 112-1, except for the first and last scans, which may be trimmed based on the definition of the scan area 112-1. The larger the number of exposure units, the fewer scans that can be performed, which can correspond to a higher throughput.

[0021] Each exposure unit may 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 scan area (mounted either on the same bridge or on a different bridge), the exposure unit corresponding to the first scan area may intrude into the second scan area. Similarly, the exposure unit corresponding to the second scan area may intrude into the first scan area. For example, exposure unit 1 may intrude into scan area 112-2 and / or scan area 112-3, and exposure unit 2 may intrude into scan area 112-1 and / or scan area 112-4. Thus, shared exposure may be observed at the boundaries or "stitching lines" between adjacent exposure units of the same bridge and / or exposure units on different bridges.

[0022] The stitch lines may be defined by a clipping layer, which may be a software-defined layer that sets the scan path boundaries for each exposure unit during the movement of the stage assembly 110. Due to non-ideal printing conditions, the stitch lines may be visible on the substrate after printing. For example, if the actual location of the exposure units is shifted by about 1 micron, there may be a 1 micron wide gap or double exposed band near the stitch lines. In this illustrative example, the stitch lines are shown as straight lines (as the scan area is rectangular in shape), but the stitch lines may be curved (e.g., wavy).

[0023] For example, the path 130 of the exposure unit 120-1 is shown as an example. The path 130 proceeds in a snake-like manner. More specifically, during scanning, the stage assembly 110 moves in the X direction (i.e., from right to left) across the scan region 120-1 while the exposure unit 120-1 patterns a line across the scan region 120-1. When the stage assembly 110 reaches the left edge of the scan region 112-1, it moves in the Y direction (i.e., up) and then moves in the X direction (i.e., from left to right) to pattern another line across the scan region 120-1. The path 130 proceeds in this snake-like manner until it reaches the opposite end of the scan region 120-1, at which point a complete image is patterned on the substrate. The image may be further developed for substrate etching. The distance of stage travel in the Y direction during scanning, "Y1," may be any suitable distance according to the embodiments described herein. In some embodiments, Y1 may range between about 150 mm and about 180 mm. For example, Y1 may be about 164 mm. The scan distance in the X direction for each exposure unit corresponds to the length of bridges 114-1 and 114-2, in an embodiment. The total width of the scan area, "Y2", may be any suitable width according to embodiments described herein. In some embodiments, "Y2" may range between about 1600 mm and about 2000 mm. For example, Y2 may be about 1800 mm. The travel distance for each scan (e.g., in the X direction) may vary due to differences in substrate size. 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.

[0024] The scanning process shown in Figure 1 may, in embodiments, be used to create a display (e.g., a flat panel display). In some embodiments, the display is a liquid crystal display (LCD). Further details regarding the scan path 130 and exposure unit 120-1 are now described below with reference to Figures 2A-2D.

[0025] 2A-2D are top-down views 200A-200B of a scanning path of a substrate 220 through a single digital lithography exposure unit ("exposure unit") 210 of a digital lithography system, according to some embodiments. The exposure unit 210 can be, for example, the exposure unit 120-1 of the digital lithography system 100 described above with reference to FIG. 1. The substrate 220 is disposed on a stage (not shown).

[0026] 2A shows an exposure unit 210 and a scan area 220 of a substrate prior to a first scan being performed using the exposure unit 210. An edge 222 of the scan area 220 may be aligned with an edge 212 of the exposure unit 210 prior to the first scan being performed. A stage moves the substrate in the XY direction(s) according to a digital lithography scanning procedure that performs several scans across the scan area 220.

[0027] 2B shows the formation of scanned area 230-1 in the scan region 220 after a first scan is performed using the exposure unit 210. More specifically, the stage moves the substrate in the positive X direction under the exposure unit 210 to form scanned area 230-1.

[0028] 2C shows the formation of scanned area 230-2 after a second scan is performed using exposure unit 210. More specifically, after a first scan is performed using exposure unit 210, the stage moves the substrate in the positive Y direction to align exposure unit 210 with the next designated region, and then the stage moves the substrate in the negative X direction under exposure unit 210 to form scanned area 230-2.

[0029] 2D shows the formation of scanned area 230-2 after a second scan is performed using exposure unit 210. More specifically, after a second scan is performed using exposure unit 210, the stage moves the substrate in the positive Y direction to align exposure unit 210 with the next designated area, and then the stage moves substrate 220 in the positive X direction under exposure unit 210 to form scanned area 230-3. Additional scans may be performed to complete the scan.

[0030] During the scanning process described above, one or more "Mura" problems may be observed. Mura is a Japanese term that generally refers to visible variations across a display caused by the scanning process.

[0031] One example of mura is "scan mura" that occurs after every scan. For example, one type of scan mura 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, every time a scan is performed to scan a line or to "paint a stripe," the top edge of the scan is brighter or darker than the bottom edge. This can have a negative impact on the patterning dimensions. Another example of mura is "vibration mura," where vibrations resulting from the operation of a digital lithography system can cause the exposure unit to vibrate, resulting in scan choppiness. This can cause visible variations across the display, as the exposure unit vibrations may not be spatially synchronized.

[0032] Another example of mura is "border mura," where an abrupt change in appearance may 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, border mura may occur at the boundary between areas scanned by adjacent pairs of exposure units of a given bridge (e.g., the boundary between scan area 112-2 and scan area 112-4 in FIG. 1). As another example, border mura may occur at the boundary between areas scanned by adjacent pairs of exposure units corresponding to different bridges (e.g., the boundary between scan area 112-1 and scan area 112-2 in FIG. 1).

[0033] There may be a variety of different microscopic and / or macroscopic causes of boundary unevenness. For example, if one exposure unit is outputting more light during a scan than an adjacent exposure unit, an abrupt change in the line width of the printed lines may be observed across the boundary between those exposure units. As another example, if one exposure unit is out of focus compared to another exposure unit, the photoresist sidewall profile corresponding to each exposure unit may be different. For example, an exposure unit with better focus may have more vertical sidewalls compared to the more sloping sidewalls of an exposure unit with poorer focus. Thus, problems may exist at the boundaries of adjacent scan regions.

[0034] As described in further detail herein, unevenness (e.g., boundary unevenness) may be addressed by performing exposure unit boundary smoothing to smooth boundaries (e.g., stitch lines) between scan areas scanned by adjacent exposure units. The exposure unit boundaries may correspond to edges of areas scanned by the exposure units. For example, exposure unit boundary smoothing may be performed to create a gradual transition (e.g., blend the boundaries) between areas scanned by different exposure units.

[0035] In some embodiments, performing exposure unit boundary smoothing includes performing exposure unit boundary shifting. Exposure unit boundary shifting may be performed to shift the exposure unit boundary for each pass of the exposure unit. A pass refers to a single iteration of a scan path to pattern or print a line on a substrate (conceptually similar to applying a single coating of paint). By performing multiple (i.e., two or more) passes to pattern a line on a substrate and shifting the exposure unit boundary after each pass, the line may be smoothed or refined (conceptually similar to applying multiple coatings of paint to smooth a paint stroke). Thus, in an embodiment, the digital lithography process may be a multi-pass digital lithography process. In the case of a multi-pass digital lithography process, multiple passes may be performed over the same area to increase the exposure of that area.

[0036] In some embodiments, performing exposure unit boundary smoothing includes performing dose blending, where dose refers to the amount of radiation or light to which an area is exposed. Dose blending, in effect, attempts to "mimic" the results of exposure unit boundary shifting without the need to perform multi-pass lithography. For dose blending, the intensity of the light source may be adjusted during scanning of one or more portions of the area associated with the exposure unit. Alternatively or additionally, the number of passes applied to different portions of the area associated with the exposure unit may be varied to provide different exposure levels by the exposure unit. For example, a first exposure unit may apply 100% (or two passes) of the target light intensity to achieve a full dose to most of the area covered by the first exposure unit. However, for a portion of the area covered by the first exposure unit, the first exposure unit may apply 50% (or a single pass at full intensity) of the target light intensity to provide ½ dose. A second exposure unit may cross over the area served by the first exposure unit and apply 50% of the target light intensity (or a single pass at full intensity) to the portion of the area that receives 50% of the dose by the first exposure unit. This effectively "blends" the dose or exposure of the two exposure units for that portion of the area, so that the portion of the area receives a partial dose from one exposure unit and a partial dose from another exposure unit. As described in more detail herein, dose blending may be achieved by performing "local multi-passes" at corresponding scan area boundaries. More specifically, multiple passes of scanning may be performed with respect to the boundaries to achieve the dose blending effect. Dose blending may provide a trade-off between blending and takt time compared to exposure unit boundary shifting. In some embodiments, a combination of exposure unit boundary shifting and dose blending is performed.

[0037] Exposure unit boundary shifting and / or dose blending may be implemented to address boundary smoothing between adjacent scan areas for exposure units mounted on the same bridge (the "one bridge example"), or to address boundary smoothing between adjacent scan areas for exposure units mounted on different bridges (the "two bridge example"). Further details regarding exposure unit boundary shifting and dose blending are described below with reference to Figures 3-7.

[0038] 3A-3C are diagrams 300A-300C illustrating examples 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, diagrams 300A-300C can each correspond to a clipping layer that defines the boundaries of the exposure units.

[0039] In FIG. 3A, diagram 300A shows a first scan area 310-A ​​corresponding to a first exposure unit and a second scan area 320-A corresponding to a second exposure unit, separated by a boundary 315. The first exposure unit and the second exposure unit may be adjacent exposure units mounted on the same bridge. For example, the first exposure unit may correspond to exposure unit 1 of FIG. 1, and the second exposure unit may correspond to exposure unit 2 of FIG. 1. Alternatively, the first exposure unit and the second exposure unit may be adjacent exposure units mounted on different bridges. For example, the first exposure unit may correspond to exposure unit 1 of FIG. 1, and the second exposure unit may correspond to exposure unit 12 of FIG. 1.

[0040] In this example, there is no exposure unit boundary smoothing between the first scan area 310-A ​​and the second scan area 320-A. More specifically, the first exposure unit is responsible for 100% of the scan in the first scan area 310-A ​​up to the boundary 315, and then the second exposure unit is responsible for 100% of the scan in the second scan area 320-A up to the boundary 315. In other words, the first scan area 310-A ​​has received 100% of the dose from the first exposure unit, and the second scan area 320-A has received 100% of the dose from the second exposure unit.

[0041] In FIG. 3B, diagram 300B shows a first scan area 310-B corresponding to a first exposure unit and a second scan area 320-B corresponding to a second exposure unit. Here, exposure unit boundary smoothing between the first scan area 310-B and the second scan area 320-B has resulted in sawtooth blending. More specifically, the first exposure unit is programmed to extend into the original scan area corresponding to the second exposure unit (e.g., scan area 310-B in FIG. 3A), and the second exposure unit is programmed to extend into the original scan area corresponding to the first exposure unit (e.g., scan area 310-A ​​in FIG. 3A). The sawtooth blending is illustrated in FIG. 3B by vertical boundaries 330-1 to 330-4 and horizontal boundaries 335-1 to 335-3. Boundaries 330-1 through 330-4 and 335-1 through 335-1 may not be visible and are provided to illustrate the exposure unit boundary smoothing shown in FIG. 3B. A mixed dose region is defined between vertical boundary 330-1 and vertical boundary 330-4. For the region defined by horizontal boundary 335-1, the first exposure unit provides a 75% dose and the second exposure unit provides a 25% dose. For the region defined by horizontal boundary 335-2, both the first and second exposure units provide a 50% dose. For the region defined by horizontal boundary 335-3, the first exposure unit provides a 25% dose and the second exposure unit provides a 75% dose.

[0042] The boundary smoothing shown in FIG. 3B can be obtained by performing exposure unit boundary shifting and / or dose blending. For exposure unit boundary shifting, multiple passes can be performed to obtain sawtooth blending. In this illustrative example, four passes can be performed, with the exposure unit boundaries shifted after each pass (i.e., four-pass boundary shifting). For example, in the one-bridge case, the exposure unit boundaries can be shifted vertically (e.g., by shifting the clipping layer vertically), and in the two-bridge case, the exposure unit boundaries can be shifted horizontally (e.g., by shifting the clipping layer horizontally). For dose blending, while performing a single pass, a "local multi-pass" can be performed on the original boundary 315 to provide a specified amount of dose for each of the exposure units. In this illustrative example, the first exposure unit and the second exposure unit can each provide four dose amounts (100%, 75%, 50% and 25%) to achieve the exposure unit boundary smoothing shown in FIG. 3B.

[0043] In Figure 3C, diagram 300C shows a first exposure unit region 310-C and a second exposure unit region 320-C with gradual blending corresponding to a diagonal boundary 340. The gradual blending to achieve the diagonal boundary 340 is an ideal theory for boundary smoothing in that the blending can be obtained after a suitable number (e.g., an infinite number) of passes during exposure unit boundary shifting and / or after a suitable fine (e.g., infinitesimally fine) blending of doses with respect to the boundaries for each of the exposure units during dose blending.

[0044] 4 is a diagram 400 of an example scanning configuration ("configuration") of a digital lithography exposure unit ("exposure unit") in a one-bridge implementation, according to some embodiments. Diagram 400 shows a first configuration 410 without exposure unit boundary smoothing or blending. More specifically, first configuration 410 includes a first scan area 412 corresponding to 100% dose of a first exposure unit and a second scan area 414 corresponding to 100% dose of a second exposure unit. For example, scan areas 412 and 414 may be defined using clipping layers.

[0045] Diagram 400 further illustrates a second configuration 420 illustrating an example of exposure unit boundary smoothing or blending. More specifically, second configuration 420 includes a first unblended scan area 421 corresponding to 100% dose of the first exposure unit and a second unblended scan area 422 corresponding to 100% dose of the second exposure unit. Furthermore, second configuration 420 includes several blended scan areas 423-425. Blended scan area 423 can correspond, as an example, to about 75% dose of the first exposure unit and about 25% dose of the second exposure unit. Blended scan area 424 can correspond to about 50% dose of the first exposure unit area and about 50% dose of the second exposure unit area. Blended scan area 425 can correspond to about 25% dose of the first exposure unit and about 75% dose of the second exposure unit.

[0046] In some embodiments, a multi-pass exposure process may be performed to achieve scan areas 421-425. More specifically, exposure unit boundary shifting may be performed by shifting the exposure unit boundary vertically after each pass (e.g., the clipping layer shifts vertically after each pass). In this illustrative example, four passes may be performed. For example, the four passes of the first exposure unit may be (1) scan area 421, (2) scan area 421+423, (3) scan area 421+423+424, and (4) scan area 421+423+424+425.

[0047] The boundaries between the scan areas 421-425 are shown as being straight in the second configuration 420. However, other variations are contemplated in which the boundaries between the scan areas 421-425 are not straight. For example, the boundaries between the scan areas 421-425 may be wavy. Because the human eye is more sensitive to straight edges, a non-straight boundary may not appear as pronounced for the same degree of mismatch between the first and second exposure units.

[0048] FIG. 5 illustrates a diagram 500 showing example scanning configurations ("configurations") of a digital lithography exposure unit ("exposure unit") in a two-bridge implementation, according to some embodiments. Diagram 500 illustrates several configurations 510-1 through 510-4, which correspond to a first pass, a second pass, a third pass, and a fourth pass, respectively, performed by exposure units A through D during a four-pass exposure process. In this example, exposure units A through D are located in adjacent scan regions, exposure units A and B are mounted on a first bridge, and exposure units C and D are mounted on a second bridge. For example, with reference to FIG. 1, exposure unit A can correspond to exposure unit 2, exposure unit B can correspond to exposure unit 1, exposure unit C can correspond to exposure unit 13, and exposure unit D can correspond to exposure unit 12.

[0049] Each of the configurations 510-1 to 510-4 is organized as a 5×5 grid of regions, including region 520, with the letters “A” to “D” written in each region representing which exposure unit is responsible for performing a scan in that region during the corresponding pass. For example, exposure unit A is responsible for performing a scan in region 520 for each of the four passes. The configurations 510-1 to 510-4 are shown as completely separate or independent for purposes of illustration. It should be understood that the boxes in corresponding locations in the grid of each of the configurations 510-1 to 510-4 substantially overlap during each pass. For example, the regions 520 in each of the configurations 510-1 to 510-4 are substantially equivalent locations.

[0050] The paths shown in the configurations 510-1 to 510-4 are designed to collectively satisfy a predefined blending specification. For example, the blending specification may be provided in a data structure (e.g., a table). The blending specifications satisfied by the configurations 510-1 to 510-4 are shown in the table below. TIFF0007657981000001.tif32170 Table 1 is organized as a 5x5 table, with each box defining the total number of scans to be performed by one or more of exposure units A-D in the corresponding region at the end of the four-pass process. For example, entry "4A" in Table 1 indicates that exposure unit A performs a total of four scans in region 520 (i.e., exposure unit A is responsible for 100% of region 520 for each pass). Thus, region 520 in each of configurations 510-1-510-4 has the letter "A" written in it. As another example, entry "3A+C" in Table 1 indicates that exposure unit A performs a total of three scans and exposure unit C performs one scan in the region adjacent to the right edge of region 520. In this illustrative example, as shown in configurations 510-1 to 510-4, exposure unit A performs a scan in the region during the first pass, the third pass, and the fourth pass, and exposure unit C performs a scan in the region during the second pass. That is, exposure unit A contributes 75% of the scan in the region, and exposure unit C contributes 25% of the scan in the region. However, this scan ordering is not limiting. For example, exposure unit C (as opposed to exposure unit A shown in configuration 510-1) can perform a scan in the region during the first pass, and exposure unit A (as opposed to exposure unit C shown in configuration 510-2) can perform a scan in the region during the second pass, the third pass, and the fourth pass. As yet another example, the entry "A+B+C+D" in Table 1 indicates that each of exposure units A to D performs one scan in the central region of configurations 510-1 to 510-4. In this illustrative example, exposure unit A performs a scan in the central region during a first pass, exposure unit C performs a scan in the central region during a second pass, exposure unit B performs a scan in the central region during a third pass, and exposure unit D performs a scan in the central region during a fourth pass, however, as above, this scan ordering is not limiting (as long as each of exposure units A-D performs a single scan during a respective pass of the multi-pass process).

[0051] 6 is a diagram 600 illustrating another example of dose allocation of a digital lithography exposure unit in a one-bridge implementation, according to some embodiments. Diagram 600 includes a dose allocation 610-1 corresponding to a first exposure unit and a dose allocation 610-2 corresponding to a second exposure unit. For illustrative purposes, dose allocation 610-1 and dose allocation 610-2 are shown as separate or independent. However, in practice, dose allocation 610-1 and dose allocation 610-2 correspond to vertically aligned regions.

[0052] For example, dose allocation 610-1 includes a dose value 612-1 for a first exposure unit in a first region, a dose value 614-1 for a first exposure unit in a second region, a dose value 616-1 for a first exposure unit in a third region, and a dose value 618-1 for a first exposure unit in a fourth region. Dose allocation 610-2 includes a dose value 612-2 for a second exposure unit in a fifth region, a dose value 614-2 for a second exposure unit in the second region, a dose value 616-2 for a second exposure unit in the third region, and a dose value 618-2 for a second exposure unit in the fourth region. In other words, the second region includes a mix of dose values ​​614-1 and 614-2, the third region includes a mix of dose values ​​616-1 and 616-2, and the fourth region includes a mix of dose values ​​618-1 and 618-2.

[0053] The sum of the mixed dose values ​​should sum to 100% of the total dose for the corresponding region. For example, dose value 612-1 and dose value 612-2 can each be 100% so that each exposure unit contributes solely to 100% dose for the first region and the fifth region, respectively. Dose value 614-1 can be 75% as an example, and dose value 614-2 can be 25% as an example, with each exposure unit's contribution summing to 100% of the total dose for the second region. Dose value 616-1 and dose value 616-2 can be 50% as an example, with each exposure unit's contribution summing to 100% of the total dose for the third region. Dose value 618-1 can be 25% as an example, and dose value 618-2 can be 75% as an example, with each exposure unit's contribution summing to 100% of the total dose for the fourth region. However, these dose value examples are merely examples, and any suitable number of dose value mixtures N may be implemented in accordance with the embodiments described herein. The clipping layers corresponding to the first and second exposure units should be aligned to provide the overlap required to achieve the dose value mixture.

[0054] FIG. 7 is a diagram 700 illustrating an example dose allocation of a digital lithography exposure unit in a two-bridge implementation, according to some embodiments. Diagram 700 includes a dose allocation 710-A corresponding to exposure unit A, a dose allocation 710-B corresponding to exposure unit B, a dose allocation 710-C corresponding to exposure unit C, and a dose allocation 710-D corresponding to exposure unit D. In this example, exposure units A-D are located in adjacent scan regions, exposure units A and B are mounted on a first bridge, and exposure units C and D are mounted on a second bridge. For example, referring to FIG. 1, exposure unit A can correspond to exposure unit 2, exposure unit B can correspond to exposure unit 1, exposure unit C can correspond to exposure unit 13, and exposure unit D can correspond to exposure unit 12.

[0055] The number in each box of dose allocation 710-A through 710-D represents the relative dose for the corresponding exposure unit in each region, with the actual dose being divided by 16. For example, if the number in a box shown in dose allocation 710-A is "8," then the actual dose contribution for exposure unit A for the corresponding region is 8 / 16=0.5 or 50%.

[0056] For purposes of illustration, dose allocations 710-A through 710-D are shown as separate. In reality, however, dose allocations 710-A through 710-D overlap with respect to 3×3 box regions 720A through 720-D to form a blending zone such that the total dose from each of exposure units A through D sums to 100% (i.e., the relative dose sums to 16). For example, the total doses corresponding to the bold and underlined values ​​in each of exposure unit dose allocations 710-A through 710-D are: TIFF0007657981000002.tif9170. In this illustrative example, nine dose values ​​for each exposure unit A-D (corresponding to relative doses of 1, 2, 3, 4, 6, 8, 9, 12 and 16) are achieved. However, these dose value examples are merely examples and any suitable number of dose value blends N may be implemented in accordance with embodiments described herein.

[0057] 8A-8C are diagrams illustrating examples of digital lithography exposure unit dose allocation, according to some embodiments. FIG. 8A illustrates diagram 800A without exposure unit boundary smoothing or blending. For example, diagram 800A illustrates a first scan area 810-A corresponding to a first exposure unit, a second scan area 820-A corresponding to a second exposure unit, and a third scan area 830-A corresponding to a third exposure unit. Each scan area 810-A-830-A is associated with several scans, each having a scan width. In this exemplary embodiment, six scans (1-6) are performed by each exposure unit in each scan area. However, the number of scans should not be considered limiting. A distance "X" is shown, indicating the exposure unit scan distance. Since there is no dose blending, each exposure unit is responsible for 100% of the scans in its corresponding area. Here, and as described below with respect to Figures 8B and 8C, the scan performed by the first exposure unit is indicated by no fill, the scan performed by the second exposure unit is indicated by stripes, and the scan performed by the third exposure unit is indicated by dots.

[0058] Scans 2-5 generally correspond to scans performed in the center of the corresponding scan area 810A-830A, and scans 1 and 6 generally correspond to scans performed toward the edge or boundary of the corresponding scan area 810A-830A. Scans 2-5 generally have the same or similar scan width. However, it can be observed that for scans 1 and 6, the scan width can be smaller than the scan width of scans 2-5. This can result from the manner in which the digital lithography system is assembled and calibrated. For example, each exposure unit can be installed to have a tolerance of about + / - 1 millimeter (mm). The system can then be calibrated to determine the location of each exposure unit. The calibration can identify the scan width for each scan in view of how each exposure is arranged within the digital lithography system.

[0059] FIG. 8B shows a diagram 800B with exposure unit boundary smoothing according to a first implementation. For example, diagram 800B shows scan areas 810-B to 850-B. Each scan area 810-B to 850-B is associated with several scans, each having a scan width. However, the number of scans and / or the scan width should not be considered as limiting.

[0060] As shown, a first exposure unit performs scans 1 through 4A in scan area 810-B, with scan 4A corresponding to the first performance of scan 4 by the first exposure unit, where the first exposure unit performs 100% of the scan in scan area 810-B.

[0061] In the scanning area 820-B, the first exposure unit performs scans 4B-8, where scan 4B corresponds to the second execution of scan 4 by the first exposure unit. Additional scans 7 and 8 were used to extend the operation of the first exposure unit to the original scanning area of ​​the second exposure unit (e.g., scanning area 820-A in FIG. 8A). Moreover, the second exposure unit performs scans -1-2A, where scan 2A corresponds to the first execution of scan 2 by the second exposure unit. Additional scans -1 and -0 were used to extend the second exposure unit to the original scanning area of ​​the first exposure unit (e.g., scanning area 810-A in FIG. 8A). Here, each of the first exposure unit and the second exposure unit scans about 50% of the scan of the scanning area 820-B.

[0062] In scanning area 830-B, the second exposure unit performs scans 2B to 4A, where scan 2B corresponds to the second performance of scan 2 by the second exposure unit, and scan 4A corresponds to the first performance of scan 4 by the second exposure unit. Here, the second exposure unit scans 100% of scanning area 830-B.

[0063] In the scanning area 840-B, the second exposure unit performs scans 4B-8, where scan 4B corresponds to the second execution of scan 4 by the second exposure unit. Similar to the first exposure unit, additional scans 7 and 8 were used to extend the operation of the second exposure unit to the original scanning area of ​​the third exposure unit (e.g., scanning area 830-A in FIG. 8A). Moreover, the third exposure unit performs scans -1-3A, where scan 3A corresponds to the first execution of scan 3 by the third exposure unit. Additional scans -1 and -0 were used to extend the third exposure unit to the original scanning area of ​​the second exposure unit (e.g., scanning area 820-B in FIG. 8A). Here, each of the second exposure unit and the third exposure unit scans about 50% of the scanning area 840-B.

[0064] In scan area 850-B, the second exposure unit performs scans 3B-6, where scan 3B corresponds to the second performance of scan 3 by the third exposure unit. Here, the third exposure unit performs 100% of the scan in scan area 850-B. Thus, scan area 820-B and scan area 840-B correspond to an overlapping range, where adjacent pairs of exposure units scan approximately 50% of the scan area.

[0065] Scan 4 performed by the first exposure unit, scans 2 and 4 performed by the second exposure unit, and scan 3 performed by the third exposure unit correspond to scans that cross the dose-mixing boundary between scan regions. Thus, these scans are doubled or performed twice to perform dose-mixing according to FIG. 8B. For example, for the first exposure unit, the stage can stay at the same Y position during printing of its corresponding scan 4. The first exposure unit can use 100% dose to print 4A in one scan and 50% dose to print 4B in another scan.

[0066] FIG. 8C shows diagram 800C with exposure unit boundary smoothing according to a second implementation. For example, diagram 800B shows scan areas 810-C to 890-C. Each scan area 810-C to 890-C is associated with several scans, each having a scan width. However, the number of scans and / or the scan width should not be considered limiting. A first exposure unit performs 100% of the scans in scan area 810-C, a second exposure unit performs 100% of the scans in scan area 850-C, and a third exposure unit performs 100% of the scans in scan area 890-C.

[0067] As shown, a first exposure unit performs scans 1 through 4A in scan area 810-C, where scan 4A corresponds to a first portion of scan 4 performed by the first exposure unit, where the first exposure unit scans 100% of scan area 810-C.

[0068] In the scan area 820-C, the first exposure unit performs scans 4B and 5A, where scan 4B corresponds to the second portion of scan 4 performed by the first exposure unit, and scan 5A corresponds to the first portion of scan 5 performed by the first exposure unit. Besides, the second exposure unit performs scans -1 and 0A, where scan 0A corresponds to the first portion of scan 0 performed by the second exposure unit. The additional scans -1 and -0 were used to extend the second exposure unit to the original scan area of ​​the first exposure unit (e.g., scan area 810-A in FIG. 8A). Here, the first exposure unit scans about 75% of the scan area 820-C, and the second exposure unit scans about 25% of the scan area 820-C.

[0069] In the scanning area 830-C, the first exposure unit performs scans 5B to 7A, where scan 6B corresponds to the second portion of scan 6 performed by the first exposure unit, and scan 7A corresponds to the first portion of scan 7 performed by the first exposure unit. Moreover, the second exposure unit performs scans 0B and 1A, where scan 0B corresponds to the second portion of scan 0 performed by the second exposure unit, and scan 1A corresponds to the first portion of scan 1 performed by the second exposure unit. Here, each of the first exposure unit and the second exposure unit scans about 50% of the scanning area 830-C.

[0070] In the scan area 840-C, the first exposure unit performs scans 7B and 8, where scan 7B corresponds to the second portion of scan 7 performed by the first exposure unit. Moreover, the second exposure unit performs scans 1B and 2A, where scan 1B corresponds to the second portion of scan 1 performed by the second exposure unit, and scan 2A corresponds to the first portion of scan 2 performed by the second exposure unit. Here, the first exposure unit scans about 25% of the scan area 840-C, and the second exposure unit scans about 75% of the scan area 840-C.

[0071] For scan areas 820-C to 840-C, additional scans 7 and 8 were used to extend the first exposure unit into the original scan area of ​​the second exposure unit (e.g., scan area 820-A in FIG. 8A). Moreover, additional scans -1 and -0 were used to extend the second exposure unit into the original scan area of ​​the first exposure unit (e.g., scan area 810-A in FIG. 8A).

[0072] In the scanning area 850-C, the second exposure unit performs scans 2B to 4A, where scan 2B corresponds to a second portion of scan 2 performed by the second exposure unit, and scan 4A corresponds to a first portion of scan 4 performed by the second exposure unit, where the second exposure unit scans 100% of the scanning area 850-C.

[0073] In the scanning area 860-C, the second exposure unit performs scans 4B to 6A, where scan 4B corresponds to the second portion of scan 4 performed by the second exposure unit, and scan 6A corresponds to the first portion of scan 6 performed by the second exposure unit. Besides, the third exposure unit performs scans -1 and 0A, where scan 0A corresponds to the first portion of scan 0 performed by the third exposure unit. Here, the second exposure unit scans about 75% of the scanning area 860-C, and the third exposure unit scans about 25% of the scanning area 860-C.

[0074] In the scanning area 870-C, the second exposure unit performs scans 6B and 7A, where scan 6B corresponds to the second portion of scan 6 performed by the second exposure unit, and scan 7A corresponds to the first portion of scan 7 performed by the second exposure unit. Moreover, the third exposure unit performs scans 0B through 2A, where scan 0B corresponds to the second portion of scan 0 performed by the third exposure unit, and scan 2A corresponds to the first portion of scan 2 performed by the third exposure unit. Here, each of the second exposure unit and the third exposure unit scans about 50% of the scanning area 870-C.

[0075] In the scanning area 880-C, the second exposure unit performs scans 7B and 8, where scan 7B corresponds to the second portion of scan 7 performed by the second exposure unit. Moreover, the third exposure unit performs scans 2B to 3A, where scan 2B corresponds to the second portion of scan 2 performed by the third exposure unit, and scan 3A corresponds to the first portion of scan 3 performed by the third exposure unit. Here, the second exposure unit scans about 25% of the scanning area 880-C, and the third exposure unit scans about 75% of the scanning area 880-C.

[0076] For scan areas 860-C to 880-C, additional scans 7 and 8 were used to extend the second exposure unit into the original scan area of ​​the third exposure unit (e.g., scan area 830-A in FIG. 8A). Moreover, additional scans -1 and -0 were used to extend the third exposure unit into the original scan area of ​​the second exposure unit (e.g., scan area 820-A in FIG. 8A).

[0077] In scan region 890-C, the third exposure unit performs scans 3B-6, where scan 3B corresponds to a second portion of scan 3 performed by the third exposure unit, where the third exposure unit performs 100% of the scans in scan region 890-C.

[0078] Scans 4, 5 and 7 performed by the first exposure unit, scans 0, 1, 2, 4, 6 and 7 performed by the second exposure unit, and scans 0, 2 and 3 performed by the third exposure unit correspond to scans that penetrate the dose-mixing boundaries between scan regions. These scans are therefore doubled or performed twice with respect to the corresponding dose-mixing boundaries to perform the dose-mixing according to FIG. 8C.

[0079] 9 illustrates a flow diagram of a method 900 for implementing digital lithography exposure unit boundary smoothing, according to some embodiments. The method may be performed by processing logic, which may comprise hardware (circuitry, dedicated logic, etc.), computer-readable instructions (running on a general-purpose computer system or dedicated machine), or a combination of both. In an illustrative example, the method 900 may be performed by a processing device of a digital lithography system. It should be noted that the blocks illustrated in FIG. 9 may be performed simultaneously or in a different order than that illustrated.

[0080] At block 910, processing logic receives instructions to perform a digital photolithography process to pattern a substrate, and at block 920, processing logic initiates the digital lithography process to pattern the substrate in accordance with the instructions. The substrate may be disposed on a stage, and the stage may move in the XY directions under a digital lithography exposure unit ("exposure unit") in accordance with the instructions. For example, the instructions may be executed to implement exposure unit boundary smoothing (e.g., exposure unit boundary shifting and / or dose blending).

[0081] At block 930, the processing logic performs exposure unit boundary smoothing for a first exposure unit and a second exposure unit during the digital lithography process. The first exposure unit corresponds to a first scan area and the second exposure unit corresponds to a second scan area adjacent to the first scan area. Implementing the exposure unit boundary smoothing can include extending the first exposure unit into the second scan area and extending the second exposure unit into the first scan area.

[0082] In some embodiments, the digital lithography process includes a multiple pass process including multiple passes, and implementing the exposure unit boundary smoothing includes performing exposure unit boundary shifting as part of the multiple pass process. For example, the exposure unit boundary shifting may be implemented in a one-bridge implementation, where the first exposure unit and the second exposure unit are mounted on the same bridge above a stage of the digital photolithography system, and performing the exposure unit boundary shifting includes performing a first pass of the multiple pass process, performing a vertical boundary shift in response to performing the first pass, and performing a second pass of the multiple pass process in response to performing the vertical boundary shift. Further details regarding the one-bridge implementation of exposure unit boundary shifting were described above with reference to FIG. 4.

[0083] As another example, the exposure unit boundary shifting may be implemented in a two-bridge implementation, where the first exposure unit and the second exposure unit are mounted on a first bridge, and the multiple exposure units further include a third exposure unit associated with a third scan area and a fourth exposure unit associated with a fourth scan area adjacent to the third scan area, and thus the third exposure unit and the fourth exposure unit are mounted on a second bridge adjacent to the first bridge. In that case, performing the exposure unit boundary shifting would include performing multiple passes according to a blending specification indicating the total number of doses to be performed by the first exposure unit, the second exposure unit, the third exposure unit, and the fourth exposure unit in each area during the multiple pass process. Further details regarding the two-bridge implementation of the exposure unit boundary shifting were described above with reference to FIG. 5.

[0084] In some embodiments, implementing the exposure unit boundary smoothing includes performing dose mixing for the boundary between the first scan region and the second scan region. For example, the dose mixing may be implemented in a one-bridge implementation, where the first exposure unit and the second exposure unit are mounted on the same bridge on the stage of the digital photolithography system, and performing dose mixing includes having the first exposure unit contribute a first percentage of the total dose to the blended region and having the second exposure unit contribute a second percentage of the total dose to the blended region, such that the sum of the first percentage and the second percentage is equal to 100%. Further details regarding the one-bridge implementation of exposure unit boundary shifting are described above with reference to FIG. 6.

[0085] As another example, dose mixing may be implemented in a two-bridge implementation, where the first exposure unit and the second exposure unit are mounted on a first bridge, and the multiple exposure units further include a third exposure unit associated with a third scan area and a fourth exposure unit associated with a fourth scan area adjacent to the third scan area, and thus the third exposure unit and the fourth exposure unit are mounted on a second bridge adjacent to the first bridge. In that case, performing dose mixing would include having the first exposure unit contribute a first percentage of the total dose to the blended area, having the second exposure unit contribute a second percentage of the total dose to the blended area, having the third exposure unit contribute a third percentage of the total dose to the blended area, and having the fourth exposure unit contribute a fourth percentage of the total dose to the blended area, such that the sum of the first percentage, the second percentage, the third percentage, and the fourth percentage is equal to 100%. Further details regarding the two-bridge implementation of dose mixing are described above with reference to FIG.

[0086] Further details regarding the method 900, including exposure unit boundary shifting and dose mixing, are described above with reference to FIGS.

[0087] 10 is a block diagram illustrating a digital lithography system ("system") 900, according to some embodiments. As shown, the system 1000 includes a digital lithography exposure unit ("exposure unit") 1010, a stage 1020, and a processing device 1030. The processing device 1030 includes a processor 1032 operably coupled to a memory 1034. The memory can maintain instructions 1036 for performing digital lithography in the system 1000. For example, the instructions 1026 can include instructions for controlling movement of the stage 1020 and / or the exposure unit 1010. When executed, the instructions can implement a method for performing exposure unit boundary smoothing as described herein above.

[0088] FIG. 11 is a block diagram illustrating a computer system 1100, according to some embodiments. In some embodiments, the computer system 1100 is connected to other computer systems (e.g., via a network, such as a local area network (LAN), an intranet, an extranet, or the Internet). In some embodiments, the computer system 1100 operates in the capacity of a server computer or a 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 1100 is provided by a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a cellular phone, a web appliance, a server, a network router, a switch or bridge, or any device capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that device. Furthermore, the term "computer" is intended to include any collection of computers that individually or together execute a set (or sets) of instructions to perform any one or more of the methods described herein.

[0089] In a further aspect, the computer system 1100 includes a processing device 1102, a volatile memory 1104 (e.g., random access memory (RAM)), a non-volatile memory 1106 (e.g., read-only memory (ROM) or electrically erasable programmable ROM (EEPROM)), and a data storage device 1116, which communicate with each other via a bus 1108.

[0090] In some embodiments, the processing device 1102 is provided by one or more processors, such as a general-purpose processor (e.g., a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a microprocessor implementing other types of instruction sets or microprocessors implementing a combination of types of instruction sets), or a special-purpose processor (e.g., an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), or a network processor).

[0091] In some embodiments, computer system 1100 further includes a network interface device 1122 (e.g., coupled to network 1174). In some embodiments, computer system 1100 also includes a video display unit 1110 (e.g., LCD), an alphanumeric input device 1112 (e.g., keyboard), a cursor control device 1114 (e.g., mouse), and a signal generating device 1120.

[0092] In some implementations, the data storage device 1116 includes a non-transitory computer-readable storage medium 1124 that stores instructions 1126 encoding any one or more of the methods or functions described herein. For example, the instructions 1126 may include instructions for controlling movement of a stage of a digital lithography system and / or a digital lithography exposure unit ("exposure unit"), which when executed may implement a method for performing exposure unit boundary smoothing described herein.

[0093] In some embodiments, the instructions 1126 also reside, completely or partially, within the volatile memory 1104 and / or within the processing device 1102 during execution thereof by the computer system 1100, and thus, in some embodiments, the volatile memory 1104 and the processing device 1102 also constitute machine-readable storage media.

[0094] Although computer readable storage medium 1124 is shown as a single medium in the illustrative example, the term "computer readable storage medium" is intended to include a single medium or multiple media (e.g., centralized or distributed databases and / or associated caches and servers) that store one or more sets of executable instructions. The term "computer readable storage medium" is intended to include any tangible medium that is capable of storing or encoding a set of instructions for a computer to execute, causing the computer to perform any one or more of the methodologies described herein. The term "computer readable storage medium" is intended to include, but is not limited to, solid-state memories, optical media, and magnetic media.

[0095] In some embodiments, the methods, components, and features described herein are implemented by discrete hardware components or are 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 a hardware device. In some embodiments, the methods, components, and features are implemented in any combination of hardware devices and computer program components, or are implemented in a computer program.

[0096] Unless otherwise specified, terms such as "training," "identifying," "further training," "retraining," "causing," "receiving," "providing," "obtaining," "optimizing," "determining," "updating," "initializing," "generating," "adding," and the like refer to actions and processes performed or implemented by a computer system that manipulate data represented as physical (electronic) quantities in computer system registers and memory and transform that data into other data similarly represented as physical quantities in computer system memory or registers, or other such information storage, transmission, or display devices. In some embodiments, the terms "first," "second," "third," "fourth," and the like, as used herein, are meant as labels to distinguish between different elements and do not have any ordering meaning according to their numerical designation.

[0097] The examples described herein also relate to an apparatus for carrying out the methods described herein. In some embodiments, the apparatus includes a general-purpose computer system that is specially constructed to carry out the methods described herein or that is selectively programmed by a computer program stored in the computer system. Such a computer program is stored in a computer-readable tangible storage medium.

[0098] The methods and illustrative examples described herein are not inherently related to any particular computer or other apparatus. In some embodiments, various general-purpose systems are used in accordance with the teachings described herein. In some embodiments, more specialized apparatus are constructed to perform the methods described herein and / or each of their individual functions, routines, subroutines, or operations. Example structures for a variety of these systems are set forth in the description above.

[0099] The preceding description describes numerous specific details, such as examples of specific systems, components, methods, etc., to provide a good understanding of some 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 these specific details. In other instances, well-known components or methods are not described in detail or are presented in a simple block diagram format to avoid unnecessarily obscuring the present invention. Thus, the specific details described are by way of example only. It is contemplated that particular implementations may vary from these illustrative details and still fall within the scope of the present invention.

[0100] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or property described with respect to that embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification do not necessarily all refer 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 presented is accurate to within ±10%.

[0101] Although the operations of the methods herein are shown and described in a particular order, the order of the operations of each method may be changed such that some operations may be performed in reverse order or such that some operations may be performed, at least in part, simultaneously with other operations. In another embodiment, instructions of separate operations or sub-operations may be in an intermittent and / or alternating manner.

[0102] It should be understood that the above description is illustrative and not restrictive. Many other implementations will be apparent to those skilled in the art upon reading and understanding the above description. Although the present disclosure describes specific examples, it will be recognized that the systems and methods of the present disclosure are not limited to the examples described herein, but may be practiced with modification within the scope of the appended claims. Accordingly, the specification and drawings should be considered in an illustrative and not a restrictive sense. The scope of the present disclosure should therefore be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. a plurality of scan areas, the scan areas including a first scan area and a second scan area adjacent to the first scan area; a plurality of exposure units positioned above the plurality of scanning areas, the plurality of exposure units comprising a first exposure unit associated with the first scanning area and a second exposure unit associated with the second scanning area; a first bridge to which the first exposure unit and the second exposure unit are attached; Memory, at least one processing device operably coupled to the memory; 1. A maskless digital lithography system comprising: initiating a digital lithography process for instructed patterning of a substrate disposed on a stage, the digital lithography process being a multiple pass process including multiple passes; performing exposure unit boundary smoothing as part of the multiple pass process for at least the first exposure unit and the second exposure unit by performing exposure unit boundary shifting to shift exposure unit boundaries for each pass of an exposure unit during the digital lithography process; 1. A maskless digital lithography system for performing operations including:

2. Performing the exposure unit boundary shifting, performing a first pass of the multiple pass process; performing a vertical boundary shift in response to performing the first pass; and performing a second pass of the multiple pass process in response to performing the vertical boundary shift; The digital lithography system of claim 1 , comprising:

3. The plurality of scanning areas further includes a third scanning area and a fourth scanning area adjacent to the third scanning area; the plurality of exposure units further comprising a third exposure unit associated with the third scanning area and a fourth exposure unit associated with the fourth scanning area, the third exposure unit and the fourth exposure unit being attached to a second bridge adjacent to the first bridge; performing the exposure unit boundary shifting includes performing the multiple passes according to a blending specification indicating a total number of doses to be performed by the first exposure unit, the second exposure unit, the third exposure unit, and the fourth exposure unit in each region during the multiple pass process. The digital lithography system of claim 1 .

4. A plurality of scanning areas including a first scanning area, a second scanning area adjacent to the first scanning area, a third scanning area, and a fourth scanning area adjacent to the third scanning area; a plurality of exposure units positioned above the plurality of scanning areas, the plurality of exposure units comprising a first exposure unit associated with the first scanning area, a second exposure unit associated with the second scanning area, a third exposure unit associated with the third scanning area, and a fourth exposure unit associated with the fourth scanning area; a first bridge and a second bridge adjacent to the first bridge, the first exposure unit and the second exposure unit being attached to the first bridge, and the third exposure unit and the fourth exposure unit being attached to the second bridge; Memory, at least one processing device operably coupled to the memory; 1. A digital lithography system comprising: initiating a digital lithography process for command-patterning a substrate disposed on the stage; performing exposure unit boundary smoothing for at least the first exposure unit and the second exposure unit by performing dose blending for at least one boundary between at least the first scan area and the second scan area during the digital lithography process; and performing operations including: performing the dose blending includes having the first exposure unit contribute a first percentage of the total dose to the blended region, having the second exposure unit contribute a second percentage of the total dose to the blended region, having the third exposure unit contribute a third percentage of the total dose to the blended region, and having the fourth exposure unit contribute a fourth percentage of the total dose to the blended region, such that the sum of the first percentage, the second percentage, the third percentage, and the fourth percentage equals 100%. Maskless digital lithography system.

5. Memory, at least one processing device operably coupled to the memory; wherein the at least one processing device comprises: initiating a maskless digital lithography process for patterning a substrate in accordance with instructions, the digital lithography process being a multiple pass process including multiple passes; performing exposure unit boundary smoothing as part of the multiple pass process for at least a first exposure unit and a second exposure unit of a plurality of exposure units by performing exposure unit boundary shifting to shift an exposure unit boundary for each pass of the exposure unit during the digital lithography process; and performing operations including: the first exposure unit is associated with a first scanning area, and the second exposure unit is associated with a second scanning area adjacent to the first scanning area; the first exposure unit and the second exposure unit are attached to a first bridge; system.

6. Performing the exposure unit boundary shifting, performing a first pass of the multiple pass process; performing a vertical boundary shift in response to performing the first pass; and performing a second pass of the multiple pass process in response to performing the vertical boundary shift; The system of claim 5 , comprising:

7. The plurality of exposure units further comprises a third exposure unit associated with a third scanning area and a fourth exposure unit associated with a fourth scanning area adjacent to the third scanning area, the third exposure unit and the fourth exposure unit being attached to a second bridge adjacent to the first bridge, performing the exposure unit boundary shifting includes performing the multiple passes according to a blending specification indicating a total number of doses to be performed by the first exposure unit, the second exposure unit, the third exposure unit, and the fourth exposure unit in each region during the multiple pass process. The system of claim 5.

8. A memory; at least one processing device operably coupled to the memory; wherein the at least one processing device comprises: initiating a maskless digital lithography process to pattern the substrate in accordance with the instructions; performing exposure unit boundary smoothing for at least the first exposure unit and the second exposure unit by performing dose blending for at least one boundary between a first scan area associated with at least a first exposure unit of a plurality of exposure units and a second scan area associated with a second exposure unit of the plurality of exposure units and adjacent to the first scan area during the digital lithography process; and performing operations including: the first exposure unit and the second exposure unit are attached to a first bridge; the plurality of exposure units further comprising a third exposure unit associated with a third scanning area and a fourth exposure unit associated with a fourth scanning area and adjacent to the first scanning area; the third exposure unit and the fourth exposure unit are attached to a second bridge adjacent to the first bridge; performing the dose mixing includes having the first exposure unit contribute a first percentage of the total dose to the blended region, having the second exposure unit contribute a second percentage of the total dose to the blended region, having the third exposure unit contribute a third percentage of the total dose to the blended region, and having the fourth exposure unit contribute a fourth percentage of the total dose to the blended region, such that the sum of the first percentage, the second percentage, the third percentage, and the fourth percentage equals 100%.

9. initiating, by a processing device, a maskless digital lithography process for patterning a substrate in accordance with the instructions, the digital lithography process being a multiple pass process including multiple passes; performing, by the processing device, exposure unit boundary smoothing as part of the multiple pass process for at least a first exposure unit of a plurality of exposure units and a second exposure unit of the plurality of exposure units by performing exposure unit boundary shifting to shift an exposure unit boundary for each pass of an exposure unit during the digital lithography process, wherein the first exposure unit is associated with a first scan region and the second exposure unit is associated with a second scan region adjacent the first scan region, and the first exposure unit and the second exposure unit are attached to a first bridge; A method comprising:

10. The method of claim 1, further comprising: performing a first pass of the multiple pass process; performing a vertical boundary shift in response to performing the first pass; and performing a second pass of the multiple pass process in response to performing the vertical boundary shift; 10. The method of claim 9, comprising:

11. The plurality of exposure units further comprises a third exposure unit associated with a third scanning area and a fourth exposure unit associated with a fourth scanning area adjacent to the third scanning area, the third exposure unit and the fourth exposure unit being attached to a second bridge adjacent to the first bridge, performing the exposure unit boundary shifting includes performing the multiple passes according to a blending specification indicating a total number of doses to be performed by the first exposure unit, the second exposure unit, the third exposure unit, and the fourth exposure unit in each region during the multiple pass process.

10. The method of claim 9, comprising:

12. A method for manufacturing a substrate comprising: initiating, by a processing device, a maskless digital lithography process for patterning a substrate in accordance with the instructions; performing, by the processing device, exposure unit boundary smoothing for at least the first exposure unit and the second exposure unit during the digital lithography process by performing dose blending for at least one boundary between a first scan area associated with at least a first exposure unit of a plurality of exposure units and a second scan area associated with a second exposure unit of the plurality of exposure units and adjacent to the first scan area; the plurality of exposure units further comprising a third exposure unit associated with a third scanning area and a fourth exposure unit associated with a fourth scanning area adjacent to the first scanning area; the first exposure unit and the second exposure unit are attached to a first bridge, and the third exposure unit and the fourth exposure unit are attached to a second bridge adjacent to the first bridge; performing the dose blending includes having the first exposure unit contribute a first percentage of the total dose to the blended region, having the second exposure unit contribute a second percentage of the total dose to the blended region, having the third exposure unit contribute a third percentage of the total dose to the blended region, and having the fourth exposure unit contribute a fourth percentage of the total dose to the blended region, such that the sum of the first percentage, the second percentage, the third percentage, and the fourth percentage equals 100%. method.

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