Method to improve process window and resolution for digital lithography using two exposures

Abstract

Embodiments described herein relate to a method of printing a double exposure pattern in a lithographic environment. The method includes determining a second exposure pattern to be exposed in a lithographic process using a first exposure pattern. The second exposure pattern is determined by a rule-based processing flow or a lithographic model processing flow.

Description

TECHNICAL FIELD

[0001] Embodiments of the disclosure generally relate to photolithography systems. More particularly, embodiments of the disclosure relate to methods of printing double-exposure patterns in a photolithography environment. BACKGROUND

[0002] Photolithography is widely used in the manufacture of semiconductor devices and display devices, such as liquid crystal displays (LCDs). Large area substrates are often used in the manufacture of liquid crystal displays. Liquid crystal displays or flat panels are often used in active matrix displays, such as computer, touch panel devices, personal digital assistants (PDAs), cell phones, television screens, etc. Typically, a flat panel can include a layer of liquid crystal material that forms pixels disposed between two plates. When power from a power source is applied to the liquid crystal material, the amount of light that passes through the liquid crystal material can be controlled at the pixel locations, enabling an image to be produced.

[0003] Photolithography techniques are often used to produce electrical features that are incorporated as part of the layer of liquid crystal material that forms the pixels. Maskless photolithography techniques involve creating a virtual mask and removing selected portions of a film from the film to create a pattern in the film on a substrate. However, as device sizes decrease, there is still a need to improve resolution. SUMMARY

[0004] In one embodiment, a method is provided. The method includes receiving data defining a first exposure pattern for a photolithography process. The first exposure pattern includes one or more polygons. The method further includes determining a position and a width of a second exposure pattern based on the data defining the first exposure pattern and determining a pattern bias to be applied to the first exposure pattern during the photolithography process. The pattern bias of the first exposure pattern is determined based on the position and the width of the second exposure pattern. The method further includes converting the data of the first exposure pattern and data indicative of the pattern bias into a first virtual mask file and patterning a substrate using the first virtual mask file in a maskless photolithography device. The method further includes converting data of the second exposure pattern into a second virtual mask file and patterning the substrate using the second virtual mask file in the maskless photolithography device.

[0005] In another implementation, a method is provided. The method includes receiving data defining a first exposure pattern for a lithography process. The first exposure pattern includes one or more polygons. The method further includes inputting the data into a lithography model configured to predict aerial images and photoresist profiles based on the data. The method further includes solving the lithography model using numerical calculations to determine a position and a width of a second exposure pattern, wherein the position and the width correspond to a maximum intensity log-slope (ILS) or a depth of focus of a feature formed in a photoresist of a substrate based on the data. The method further includes determining a pattern bias to be applied to the first exposure pattern during the lithography process, solving the lithography model using numerical calculations to determine the pattern bias of the first exposure pattern, wherein the pattern bias corresponds to the maximum ILS or the depth of focus of the feature formed in the photoresist of the substrate based on the data. The method further includes converting the data of the first exposure pattern and the data indicative of the pattern bias into a first virtual mask file, and patterning the substrate using the first virtual mask file in a maskless lithography device. The method further includes converting the data of the second exposure pattern into a second virtual mask file, and patterning the substrate using the second virtual mask file in the maskless lithography device.

[0006] In yet another implementation, a system is provided. The system includes a movable stage configured to support a substrate having a photoresist disposed thereon, and a processing unit disposed on the movable stage, the processing unit configured to print a first virtual mask file and a second virtual mask file provided by a controller in communication with the processing unit. The controller is configured to receive data defining a first exposure pattern for a lithography process. The first exposure pattern includes one or more polygons. The controller is further configured to determine a position and a width of a second exposure pattern based on the data defining the first exposure pattern, and determine a pattern bias to be applied to the first exposure pattern during the lithography process. The pattern bias of the first exposure pattern is determined based on the position and the width of the second exposure pattern. The controller is further configured to convert the data of the first exposure pattern and the data indicative of the pattern bias into the first virtual mask file, and pattern the substrate using the first virtual mask file with the processing unit. The controller is further configured to convert the data of the second exposure pattern into the second virtual mask file, and pattern the substrate using the second virtual mask file with the processing unit. BRIEF DESCRIPTION OF DRAWINGS

[0007] For a more complete understanding of the above-described features of the present disclosure, reference is made to the detailed description of the embodiments in connection with the accompanying figures, in which, by way of illustration, a number of exemplary embodiments are shown. It is noted that the figures are not drawn to scale and are merely intended to conceptually illustrate the ideas underlying the present disclosure. Therefore, it is noted that other implementations can be utilized and that structural or logical changes can be made without departing from the scope of the present disclosure.

[0008] Figure 1 is a schematic diagram of a lithography environment according to embodiments described herein.

[0009] Figure 2 is a perspective view of an exemplary maskless lithography apparatus according to embodiments described herein.

[0010] Figure 3A and Figure 3B is a schematic diagram of a double-exposure pattern of a digital pattern file according to embodiments described herein.

[0011] Figure 4 is a flowchart of a method for performing a rule-based double-exposure according to embodiments described herein.

[0012] Figure 5 is a schematic diagram of a rule-based processing flow according to embodiments described herein.

[0013] Figure 6 is a flowchart of a method for performing a model-based double-exposure according to embodiments described herein.

[0014] Figure 7 is a schematic diagram of a model-based processing flow according to embodiments described herein.

[0015] Figure 8 processing system according to embodiments described herein is depicted.

[0016] For ease of understanding, the same reference numbers will be used in different drawings to designate the same elements. It is contemplated that elements and features of one embodiment can be beneficially incorporated into other embodiments without further recitation. DETAILED DESCRIPTION

[0017] Embodiments of the disclosure generally relate to lithography systems. More particularly, embodiments of the disclosure relate to methods of printing double-exposure patterns in a lithography environment. The methods include determining a second exposure pattern to be exposed using a first exposure pattern in a lithography process. The second exposure pattern is determined by a rule-based processing flow or a lithography model processing flow.

[0018] In one embodiment, a method is provided. The method includes receiving data defining a first exposure pattern for a lithography process. The first exposure pattern includes one or more polygons. The method further includes determining a position and a width of a second exposure pattern based on the data defining the first exposure pattern, and determining a pattern bias to be applied to the first exposure pattern during the lithography process. The pattern bias of the first exposure pattern is determined based on the position and the width of the second exposure pattern. The method further includes converting the data of the first exposure pattern and data indicative of the pattern bias into a first virtual mask file, and patterning a substrate using the first virtual mask file in a maskless lithography device. The method further includes converting the data of the second exposure pattern into a second virtual mask file, and patterning the substrate using the second virtual mask file in the maskless lithography device.

[0019] In another embodiment, a method is provided. The method includes receiving data defining a first exposure pattern for a lithography process. The first exposure pattern includes one or more polygons. The method further includes inputting the data into a lithography model constructed to predict aerial images and photoresist profiles based on the data. The method further includes solving the lithography model using numerical calculations to determine a position and a width of a second exposure pattern, wherein the position and the width correspond to a maximum intensity log-slope (ILS) or a depth of focus of a feature formed in a photoresist of a substrate based on the data. The method further includes determining a pattern bias to be applied to the first exposure pattern during the lithography process, solving the lithography model using numerical calculations to determine the pattern bias of the first exposure pattern, wherein the pattern bias corresponds to a maximum ILS or a depth of focus of a feature formed in the photoresist of the substrate based on the data. The method further includes converting the data of the first exposure pattern and data indicative of the pattern bias into a first virtual mask file, and patterning a substrate using the first virtual mask file in a maskless lithography device. The method further includes converting the data of the second exposure pattern into a second virtual mask file, and patterning the substrate using the second virtual mask file in the maskless lithography device.

[0020] Figure 1 is a schematic diagram of a lithography environment 100. As shown, the lithography environment 100 includes, but is not limited to, a maskless lithography device 108, a controller 110, and a communication link 101. The controller 110 is operable to facilitate transmission of digital pattern files 104 (e.g., data) provided to the controller 110. The controller 110 is operable to execute a virtual mask software application 102 and a double exposure software application 106. Each lithography environment device is operable to connect to each other via the communication link 101. Each lithography environment device is operable to connect to the controller 110 through the communication link 101. The lithography environment 100 can be located in the same area or production facility, or each lithography environment device can be located in different areas.

[0021] Each of the plurality of lithographic environment devices is additionally indexed with the method 400 operations and the method 600 operations described herein. In one embodiment, which can be combined with other embodiments described herein, each of the maskless lithography devices 108 and the controller 110 includes an on-board processor and memory, where the memory is configured to store instructions corresponding to any portion of the methods 400 and 600 described below. The communication link 101 can include at least one of a wired connection, a wireless connection, a satellite connection, etc. According to embodiments described further herein, the communication link 101 facilitates sending and receiving files to store data. Data transfer along the communication link 101 can include temporarily or permanently storing the files or data in the cloud prior to transferring or copying the files or data to the lithographic environment devices.

[0022] The controller 110 includes a central processing unit (CPU) 112, support circuits 114, and memory 116. The central processing unit 112 can be one of any form of computer processors that can be used in an industrial setting for controlling lithographic environment devices. The memory 116 is coupled to the central processing unit 112. The memory 116 can be one or more of readily available memory such as random access memory (RAM), read only memory (ROM), floppy disk, hard disk, or any other form of digital storage, local or remote. The support circuits 114 are coupled to the central processing unit 112 for supporting the processor. These circuits include cache, power supplies, clock circuits, input / output circuitry, subsystems, and the like. The controller 110 can include the central processing unit 112 coupled to the support circuits 114 and the memory 116, and an input / output (I / O) device. The controller 110 is operable to facilitate and transfer the digital pattern files 104 to the maskless lithography devices 108 via the communication link 101. The digital pattern files 104 are operable to be provided to the virtual mask software application 102 or the maskless lithography devices 108 via the controller 110.

[0023] Memory 116 may include one or more software applications, such as virtual mask software application 102 and double exposure software application 106. Memory 116 may also include stored media data used by central processing unit 112 to execute methods 400 and 600 described herein. Central processing unit 112 may be a hardware unit or combination of hardware units capable of executing software applications and processing data. In some configurations, central processing unit 112 includes a digital signal processor (DSP), application-specific integrated circuit (ASIC), and / or combinations of these units. Central processing unit 112 is configured to execute one or more software applications, such as virtual mask software application 102 and double exposure software application 106, and process stored media data, each of which may be included in memory 116. Controller 110 controls data and file transfers to and from the various lithography environment devices. Memory 116 is also configured to store instructions corresponding to any operation of method 400 or method 600 according to the embodiments described herein.

[0024] Controller 110 is operable to receive the exposure pattern of digital pattern file 104 (e.g., Figures 3A-3B As shown), the exposure pattern is transmitted to the maskless lithography apparatus 108 via communication link 101. The controller 110 can also facilitate the control and automation of the digital lithography process based on the digital pattern file 104 provided by the dual-exposure software application 106. The digital pattern file 104 (or computer instructions) readable by the controller 110 may be referred to as an imaging design file, which determines what tasks can be performed on the substrate. Although the virtual mask software application 102 and the dual-exposure software application 106 are shown as separate from the controller 110 (e.g., in the cloud), it is conceivable that the virtual mask software application 102 and the dual-exposure software application 106 may be stored locally (e.g., in memory 116).

[0025] The digital pattern file 104 corresponds to a pattern to be written into photoresist using the maskless lithography apparatus 108 output of electromagnetic radiation. In one implementation, which can be combined with other implementations described herein, the pattern can be formed with one or more patterning devices. For example, the one or more patterning devices are configured to perform ion beam etching, reactive ion etching, e-beam etching, wet etching, nanoimprint lithography (NIL), and combinations thereof. The digital pattern file 104 can be provided in different formats. For example, the format of the digital pattern file 104 can be one of a GDS format, an OASIS format, and other formats. The digital pattern file 104 includes information corresponding to exposure pattern features to be created on a substrate (e.g., the substrate 220). The digital pattern file 104 can include a region of interest corresponding to one or more structural elements. The structural elements can be built up into geometric shapes (e.g., polygons).

[0026] The double exposure software application 106 can be executed to refine and / or update the digital pattern file 104. In one implementation, which can be combined with other implementations described herein, the double exposure software application 106 is a software program stored in the memory 116 of the controller 110. The central processing unit 112 is configured to execute the software program. In another implementation, which can be combined with other implementations described herein, the double exposure software application 106 can be a remote computer server including a controller and a memory (e.g., a data store).

[0027] The digital pattern file 104 is provided to the controller 110. The controller 110 applies the double exposure software application 106 to the digital pattern file 104. The double exposure software application 106 can operate to refine and update the exposure pattern of the digital pattern file 104. In one implementation, which can be combined with other implementations described herein, the double exposure software application 106 utilizes a rule-based algorithm. The rule-based algorithm utilizes a lookup table database to refine the exposure pattern of the digital pattern file 104. The rule-based algorithm references the lookup table database to determine a position and a width of the second exposure pattern 306 (as shown in Figure 3A and 3B shown) that maximizes an intensity log-slope (ILS) and a depth of focus based on features formed in photoresist of a substrate by the digital pattern file 104. The rule-based algorithm further references the lookup table database to determine a pattern bias to be applied to the first exposure pattern 304 (as shown in Figure 3A and 3B shown). The lookup table database includes a plurality of pattern biases corresponding to a plurality of second exposure patterns 306 (as shown in Figure 3A and 3Bto maintain the first exposure pattern 304 (as shown) at a desired size Figure 3A and 3B empirical data related to the deviation required to achieve the desired size of the second exposure pattern (as shown).

[0028] The rule-based algorithm is constructed empirically, as follows: a set of test exposure patterns is designed and printed, and the test is correlated to the resulting ILS values. Pattern deviation can also be added as a variable to the set of test exposure patterns. The test exposure patterns are printed and inspected. The correct size of the set of test features with the largest ILS and / or depth of focus, and no additional printed patterns, is added to the lookup table. Thus, the lookup table includes rows of data representing the position and width of a second exposure pattern to achieve the largest possible ILS and depth of focus (or other values, based on user-defined rules) based on the provided digital pattern file 104. In some examples, the software algorithm defined herein can not select the second exposure pattern with the absolute largest ILS value from the lookup table. Rather, the software algorithm can select the second exposure pattern with the largest ILS value that also satisfies any other predetermined conditions. In such examples, the software algorithm can select the second exposure pattern with the second, third, or other largest ILS value if other exposure patterns do not satisfy the other rules of the algorithm.

[0029] Each row of the lookup table can correspond to a type of first exposure. For example, the lookup table can include a single row for a 1 μιη width isolated exposure pattern, and another row for a 1 μιη width exposure pattern with a 3 μιη polygonal spacing between adjacent exposure patterns. Other examples, variables, and values can also be considered. It is contemplated that the lookup table and / or selection can be refined or updated in response to processing results.

[0030] In another embodiment, which can be combined with other embodiments described herein, the dual exposure software application 106 utilizes a lithography model. The lithography model analyzes the exposure pattern of the digital pattern file 104 to magnify the intensity log slope (ILS) and depth of focus of the features formed in the photoresist of the substrate.

[0031] The lithography model is a physics-based model. The lithography model can use a scalar or vector imaging model. For example, the lithography model can utilize a Transmission Cross Coefficient (TCC), which is a matrix defined by the optical properties and / or the photoresist properties. Other numerical simulation techniques can be utilized, such as Resolution Enhancement Technology (RET), Optical Proximity Correction (OPC), and Source Mask Optimization (SMO). However, all such models and modeling techniques, whether now known or later developed, are intended to fall within the scope of the present disclosure. The lithography model is constructed to be defined based on the optical properties (e.g., optical properties related to the maskless lithography apparatus 108) and the photoresist properties (e.g., properties of the photoresist on which the pattern will be printed, such as material and processing properties of the photoresist). The photoresist properties include numerical aperture, exposure, illumination type, illumination size, and wavelength, and can include other values.

[0032] After the lithography model is constructed, the digital pattern file 104 is input to the lithography model. The lithography model then outputs a prediction of the aerial image and photoresist profile for the digital pattern file 104. Through post-processing operations, the ILS and depth of focus of the features formed in the photoresist of the substrate based on the digital pattern file 104 can be determined. The lithography model will utilize numerical calculations to predict the variables to achieve the maximum ILS and depth of focus (or maximum ILS and depth of focus within other predetermined constraints). The variables include the width 318 and position 320 of the second exposure pattern 306 (as shown in Figure 3A and 3B shown) and the pattern bias value of the first exposure pattern 304 (as shown in Figure 3B and

[0033] In one embodiment, the lithography model refines the digital pattern file 104 by iteratively adjusting the variables of the digital pattern file 104. The variables include the position and width of the second exposure pattern 306 (as shown in Figure 3A and 3B shown) and the bias of the first exposure pattern 304 (as shown in Figure 3A and 3BThe variables of the digital pattern file 104 are iteratively adjusted according to the rules of the lithography model or the double exposure software application 106 until the critical intensity log slope (ILS) and / or the depth of focus of the feature is achieved. Additionally or alternatively, the double exposure software application 106 refines the digital pattern file 104 by iteratively adjusting the variables of the digital pattern file 104 according to an algorithm or other rules of the double exposure software application 106 until the maximum intensity log slope (ILS) and / or the depth of focus of the feature is achieved. The lithography model also ensures that the second exposure pattern 306 is confined within the first exposure pattern 304. The lithography model ensures that a bias is applied so that the first exposure pattern 304 is within a tolerance of the desired pattern based on the digital pattern file 104.

[0034] The controller 110 provides the digital pattern file 104 to the virtual mask software application 102. The virtual mask software application 102 is operable to receive the digital pattern file 104 via the communication link 101. The virtual mask software application 102 can be a vMASC software. The digital pattern file 104 can be provided to the virtual mask software application 102 after the digital pattern file 104 is updated with the double exposure software application 106. In one embodiment, which can be combined with other embodiments described herein, the virtual mask software application 102 is a software program stored in the memory 116 of the controller 110. The central processing unit 112 is configured to execute the software program. In another embodiment, which can be combined with other embodiments described herein, the virtual mask software application 102 can be a remote computer server including a controller and memory (e.g., data storage).

[0035] The digital pattern file 104 is converted by the virtual mask software application 102 into one or more virtual mask files. For example, a first virtual mask file can correspond to the first exposure pattern and a second virtual mask file can correspond to the second exposure pattern. The virtual mask files are digital representations of the design to be printed by the maskless lithography apparatus 108. The virtual mask files are provided to the maskless lithography apparatus 108 via the communication link 101. The virtual mask files are stored in the maskless lithography apparatus 108.

[0036] Figure 2is a perspective view of an example maskless lithography apparatus 108. The maskless lithography apparatus 108 includes a stage 214 and a processing unit 204. The stage 214 is supported by a pair of rails 216. A substrate 220 is supported by the stage 214. The stage 214 is operable to move along the pair of rails 216. An encoder 218 is coupled to the stage 214 to provide position information of the stage 214 to a lithography controller 222. The maskless lithography apparatus 108 is in communication with the controller 110. The controller 110 is operable to deliver one or more virtual mask files corresponding to a first exposure pattern and a second exposure pattern, respectively, or the controller 110 is otherwise configured to perform the processes described herein.

[0037] The lithography controller 222 is generally designed to facilitate control and automation of the processing techniques described herein. The lithography controller 222 can be coupled to or in communication with the processing unit 204, the stage 214, and the encoder 218. The processing unit 204 and the encoder 218 can provide information to the lithography controller 222 regarding substrate processing and substrate alignment. For example, the processing unit 204 can provide information to the lithography controller 222 to alert the lithography controller 222 that substrate processing has been completed. The lithography controller 222 facilitates control and automation of the maskless lithography process based on the virtual mask files provided by the virtual mask software application 102. The virtual mask files readable by the lithography controller 222 determine what tasks are to be performed on the substrate. The virtual mask files correspond to exposure patterns to be written into photoresist using electromagnetic radiation.

[0038] The substrate 220 includes any suitable material used as part of a flat panel display, such as glass. In other embodiments, which can be combined with other embodiments described herein, the substrate 220 is made of other materials capable of being used as part of a flat panel display. The substrate 220 has a film layer to be patterned formed thereon, such as by pattern etching thereof, and a photoresist layer formed on the film layer to be patterned, which is sensitive to electromagnetic radiation, such as ultraviolet or deep ultraviolet "light." A positive photoresist includes photoresist portions that are respectively soluble in a photoresist developer applied to the photoresist after a pattern is written into the photoresist using electromagnetic radiation after exposure to the radiation. A negative photoresist includes photoresist portions that are respectively insoluble in a photoresist developer applied to the photoresist after a pattern is written into the photoresist using electromagnetic radiation after exposure to the radiation. The chemical composition of the photoresist determines whether the photoresist is a positive or negative photoresist. Examples of photoresists include, but are not limited to, at least one of diazonaphtoquinone, phenol formaldehyde resin, poly(methyl methacrylate), poly(methyglutarimide), and SU-8. After the photoresist is exposed to electromagnetic radiation, the photoresist is developed to leave the exposed underlying film layer. Subsequently, the underlying film is patterned through the openings in the photoresist using the patterned photoresist to form part of the electronic circuitry of the display panel.

[0039] The processing unit 204 is supported by a support 208 such that the processing unit 204 spans a pair of tracks 216. The support 208 provides openings 212 for the pair of tracks 216 and the platform 214 to pass thereunder. The processing unit 204 is a pattern generator configured to receive a virtual mask file from the virtual mask software application 102. The virtual mask file is provided to the processing unit 204 via a lithography controller 222. The processing unit 204 is configured to expose photoresist in a maskless lithography process using one or more image projection systems 206. The one or more image projection systems 206 are operable to project a write beam of electromagnetic radiation to the substrate 220. The exposure pattern generated by the processing unit 204 is projected by the image projection systems 206 to expose the photoresist of the substrate 220 to the exposure pattern. The exposure of the photoresist forms one or more different features in the photoresist. In one embodiment, which can be combined with other embodiments described herein, each image projection system 206 includes a spatial light modulator to modulate the incident light to produce the desired image. Each spatial light modulator includes a plurality of individually controllable electrically addressable elements. Based on the digital pattern file 104 (as described above), the processing unit 204 controls the image projection systems 206 to project the exposure pattern to the substrate 220. Figure 1Each electrically addressable element can be in an "on" position or an "off position. When light reaches the spatial light modulator, the electrically addressable elements in the "on" position project the plurality of write beams to a projection lens (not shown). The projection lens then projects the write beams to the substrate 220. The electrically addressable elements include, but are not limited to, digital micromirrors, liquid crystal displays (LCDs), liquid crystal over silicon (LCoS) devices, ferroelectric liquid crystal on silicon (FLCoS) devices, microshutters, micro-LEDs, VCSELs, liquid crystal displays (LCDs), or any solid-state electromagnetic radiation emitters.

[0040] Figure 3A is a schematic diagram of a double-exposure pattern 300 of the digital pattern file 104. The double-exposure pattern 300 is designed to expand the intensity log-slope (ILS) and the depth of focus of features formed in the photoresist of the substrate 220 (as shown in Figure 2 The digital pattern file 104 can include one or more polygons 302A-302C. For example, Figure 3A The first polygon 302A, the second polygon 302B, and the third polygon 302C are shown. The one or more polygons 302A-302C correspond to portions of the photoresist that will be exposed to electromagnetic radiation projected by the processing unit 204 (as shown in Figure 2 Modifying the ILS of the features to be formed in the photoresist that correspond to the one or more polygons 302A-302C of the digital pattern file 104 will modify the resolution limit of the one or more image projection systems 206 (as shown in Figure 2

[0041] The first polygon 302A includes the double-exposure pattern 300. For ease of explanation, the second polygon 302B and the third polygon 302C are shown in dashed lines to explain the double-exposure pattern 300 of the first polygon 302A. However, the second polygon 302B and the third polygon 302C can also include the double-exposure pattern 300. Although only three polygons 302A-302C are shown in Figure 3A and 3B However, the number of polygons 302 is not limited. It should be understood that any shape of polygon can be used for the one or more polygons 302A-302C such that the double-exposure pattern 300 forms one or more different features in the photoresist. The double-exposure pattern 300 is applicable to all pattern types and bright-field and dark-field exposures.

[0042] ​The first polygon 302A includes a first exposure pattern 304 and a second exposure pattern 306. The first exposure pattern 304 includes a main pattern to be printed. To improve the intensity log slope (ILS) and the depth of focus of the first exposure pattern 304, the second exposure pattern 306 is added. The second exposure pattern 306 is included such that the energy that falls on a particular location on the substrate 220 during the lithography process is the sum of the first exposure pattern 304 and the second exposure pattern 306. The ILS corresponds to the fidelity of the feature and the process window of the printing process. For example, a lower ILS corresponds to a smaller process window. As shown in Figure 3A the ILS is improved when the second exposure edge 310 of the second exposure pattern 306 is parallel to the first exposure edge 308 of the first exposure pattern 304. In some embodiments, which can be combined with other embodiments described herein, the second exposure edge 310 of the second exposure pattern 306 is not parallel to the first exposure edge 308 of the first exposure pattern 304.

[0043] The second exposure pattern 306 includes a width 318 and a position 320. The width 318 of the second exposure pattern 306 can be different along different second exposure edges 310. In some embodiments, which can be combined with other embodiments described herein, increasing the width 318 of the second exposure edge 310 increases the ILS. Each second exposure edge 310 is parallel to a corresponding first exposure edge 308. The position 320 of the second exposure pattern 306 is defined as the distance between the second exposure edge 310 and the corresponding first exposure edge 308.

[0044] In one embodiment, which can be combined with other embodiments described herein, the width 318 and the position 320 of the second exposure pattern 306 are refined based on the critical dimension 312 of the first exposure pattern 304, the polygon pitch 322, and / or the orientation of the first exposure pattern 304. The critical dimension 312 of the first exposure pattern 304 will affect the position 320 of each second exposure edge 310 of the second exposure pattern 306. For example, to refine the ILS, the position 320 of each second exposure edge 310 will be positioned within the first exposure pattern 304 based in part on the critical dimension 312. The polygon pitch 322 is defined as the distance between adjacent polygons 302. For example, as shown in Figure 3A the polygon pitch 322 between the first polygon 302A and the second polygon 302B is greater than the polygon pitch 322 between the first polygon 302A and the third polygon 302C. In addition, the orientation of the first exposure pattern 304 can affect the position 320 and / or the width 318 of the second exposure pattern 306. Since the DMD is not circularly symmetric, printing of a first exposure pattern 304 that is vertical will be different than a first exposure pattern 304 that is oriented at 45 degrees due to the way the DMD quantizes features.

[0045] Figure 3B is a schematic illustration of a double-exposure pattern 300 of the digital pattern file 104. Figure 3B A first exposure pattern 304 of the double-exposure pattern 300 with a pattern bias 314 is shown. Since the first exposure pattern 304 is added to the second exposure pattern 306, the critical dimension 312 of the first exposure pattern 304 will increase due to the increase in total energy. To compensate for the increase in the critical dimension 312, a pattern bias 314 will be implemented on the first exposure pattern 304. As shown, the pattern bias 314 is a negative bias and is applied to the first exposure pattern 304 such that the biased critical dimension 316 is smaller than the critical dimension 312. Thus, during the lithography process, the biased critical dimension 316 will expand to the critical dimension 312. The pattern bias 314 enables the critical dimension 312 to be achieved after the second exposure pattern 306 is exposed. The pattern bias 314 can be refined through simulation or experimentation. Figure 3B

[0046] Figure 4 is a flowchart of a method 400 for performing a rule-based double-exposure as shown in Figure 5 Figure 5 is a schematic illustration of a rule-based processing flow 500. Figure 5 includes elements of the lithography environment 100 as shown in Figure 1 For ease of explanation, the method 400 will be described with reference to the rule-based processing flow 500 of Figure 5 and the double-exposure pattern 300 of Figure 3A and 3B In one embodiment, which can be combined with other embodiments described herein, the method 400 can be used with any lithography process and any maskless lithography device.

[0047] At operation 401, the digital pattern file 104 is provided to the controller 110. The controller 11 can be operable to execute the double-exposure software application 106. The digital pattern file 104 corresponds to a pattern of electromagnetic radiation to be written to photoresist using the maskless lithography device 108 as shown in Figure 2 The digital pattern file 104 can include a region of interest corresponding to one or more structural elements. The structural elements can be constructed as geometric shapes, such as polygons (e.g., polygons 302A-302C as shown in Figures 3A-3B The digital pattern file 104 initially defines a first exposure pattern 304 as shown in Figures 3A-3B

[0048] ​​​At operation 402, the digital pattern file 104 is refined with the dual exposure software application 106. The digital pattern file 104 is refined to determine the position 320 and width 318 of the second exposure pattern 306 and the pattern bias 314 of the first exposure pattern 304. The digital pattern file 104 is refined to improve the intensity log slope (ILS) and the depth of focus of the features to be formed on the photoresist in the lithography process. In one embodiment, which can be combined with other embodiments described herein, the ILS is specifically refined along the first exposure edge 308 of the first exposure pattern 304. The dual exposure software application 106 determines the second exposure pattern 306 based on a rule-based second exposure algorithm 506. The rule-based second exposure algorithm 506 utilizes a lookup table to refine the exposure pattern of the digital pattern file 104.

[0049] As described above, different first exposure patterns 304 of the digital pattern file 104 can be categorized in groups and different second exposure patterns 306 can be applied to each first exposure pattern 304, and the resulting ILS and / or depth of focus values are determined and correlated to build the lookup table. For example, to repeat the first exposure pattern 304, the first exposure pattern 304 can be categorized by the critical dimension 312 and the relative position of the first exposure pattern 304. For each first exposure pattern 304, the printing variables, such as the position 320 and width 318 of the second exposure pattern 306 within the first exposure pattern 304 and the pattern bias 314, are empirically determined by different combinations of these variables. The result of maximizing the intensity log slope (ILS) and the depth of focus of the features formed in the photoresist of the substrate based on the digital pattern file 104 is recorded as a row in the lookup table. This process is repeated for different first exposure patterns 304 to complete the table. This process can be further extended to describe non-1D first exposure patterns 304.

[0050] In operation, when building the lookup table, the dual exposure software application 106 analyzes each first exposure pattern 304 on the digital pattern file 104 and determines the critical dimension 312 and the polygon pitch 322. If there are different critical dimensions 312 or polygon pitches 322 along the first exposure edge 308, the edge is split into segments with constant critical dimension 312 and polygon pitch 322. The dual exposure software application 106 references the lookup table to determine the position 320 and width 318 of the second exposure pattern 306 based on the input of the critical dimension 312 and the polygon pitch 322.

[0051] In implementations where the first exposure pattern 304 does not repeat, the lookup table can be expanded to include the critical dimension 312 of the adjacent first exposure pattern 304 as a third input value (third attribute) to the lookup table. For example, the first exposure pattern 304 with a critical dimension 312 of 2 pm is adjacent to the first exposure pattern 304 with a critical dimension 312 of 4 pm. As the first exposure pattern 304 becomes more complex, more input attributes can be added to better describe the first exposure pattern 304.

[0052] The double exposure software application 106 utilizes the lookup table to determine the pattern bias 314. The double exposure software application 106 determines the pattern bias 314 for the first exposure pattern 304 based on the rule-based first exposure algorithm 508. The lookup table database includes empirical data relating to the bias needed to maintain the critical dimension 312 of the first exposure pattern 304 based on the position 320 and width 318 of the second exposure pattern 306.

[0053] The rule-based second exposure algorithm 506 and the rule-based first exposure algorithm 508 reference the lookup table database to determine the position 320 and width 318 of the second exposure pattern 306 that maximizes the intensity log-slope (ILS) and depth of focus of the features formed in the photoresist of the substrate based on the digital pattern file 104. The rule-based second exposure algorithm 506 and the rule-based first exposure algorithm 508 also ensure that the second exposure pattern 306 is confined within the first exposure pattern 304. The rule-based second exposure algorithm 506 and the rule-based first exposure algorithm 508 also ensure that the pattern bias 314 is applied such that the first exposure pattern 304 is within the tolerance of the desired pattern based on the digital pattern file 104. In one implementation, which can be combined with other implementations described herein, the ILS is specifically refined along the first exposure edge 308 of the first exposure pattern 304. The second exposure pattern 306 for one or more polygons 302A-302C of the digital pattern file 104 can be determined.

[0054] At operation 403, the first exposure pattern 304 with the pattern bias 314 is provided to the virtual mask software application 102. The virtual mask software application 102 converts the first exposure pattern 304 for one or more polygons 302A-302C within the digital pattern file 104 into one or more quadrilateral polygons to produce a first virtual mask file. The first virtual mask file is a digital representation of the first exposure pattern 304 that will be printed by the maskless lithography device 108.

[0055] At operation 404, the first virtual mask file is provided to the maskless lithography device 108. The maskless lithography device 108 performs a lithography process to expose the substrate to the first exposure pattern included in the first virtual mask file. Optionally, after the lithography process of operation 404, the substrate can be further processed, for example by developing the photoresist and / or etching, to form a pattern on the substrate.

[0056] At operation 405, the second exposure pattern 306 is provided to the virtual mask software application 102. The virtual mask software application 102 converts the second exposure pattern 306 of the one or more polygons 302A-302C within the digital pattern file 104 to one or more quadrilateral polygons to generate a second virtual mask file. The second virtual mask file is a digital representation of the second exposure pattern 306 to be printed by the maskless lithography device 108.

[0057] At operation 406, the second virtual mask file is provided to the maskless lithography device 108. The maskless lithography device 108 performs a lithography process to expose the substrate to the second exposure pattern 306 included in the first virtual mask file. The second exposure pattern 306 is added to the first exposure pattern 304 to form a double exposure pattern (e.g., the double exposure pattern 300 of Figure 3A and 3B ). Optionally, after the lithography process of operation 404, the substrate can be further processed, for example by developing the photoresist and / or etching, to form a pattern on the substrate. The addition of the first exposure pattern 304 and the second exposure pattern 306 increases the intensity log slope and the depth of focus of the features formed on the photoresist of the substrate. Thus, the resolution and process window of the maskless lithography device 108 is improved.

[0058] Figure 6 is a flowchart of a method 600 for performing model-based double exposure as shown in Figure 7 . Figure 7 is a schematic diagram of a model-based processing flow 700. Figure 7 includes elements of the lithography environment 100 as shown in Figure 1 . For ease of explanation, the method 600 will be described with reference to the model-based processing flow 700 of Figure 7 and the double exposure pattern 300 of Figure 3A and 3B . In one implementation, which can be combined with other implementations described herein, the method 600 can be used with any lithography process and any maskless lithography device.

[0059] At operation 601, digital pattern file 104 is provided to controller 110. Controller 110 is operable to execute double exposure software application 106. Digital pattern file 104 corresponds to the image to be used by maskless lithography apparatus 108 (e.g., Figure 2 The electromagnetic radiation output (as shown) is written into a pattern in the photoresist. The digital pattern file 104 may include regions of interest corresponding to one or more structural elements. The structural elements may be constructed as geometries such as polygons (e.g., ...). Figures 3A-3B Polygons 302A-302C are shown. Digital pattern file 104 includes first exposure pattern 304 (e.g., polygons 302A-302C). Figures 3A-3B (As shown).

[0060] At operation 602, the digital pattern file 104 is refined using a double exposure software application 106. The digital pattern file 104 is refined to determine the position 320 of the second exposure pattern 306, the width 318 of the second exposure pattern 306, and the pattern deviation 314 of the first exposure pattern 304. The digital pattern file 104 is refined to increase the intensity logarithmic slope (ILS) of the features to be formed on the photoresist during the photolithography process. In one embodiment, which may be combined with other embodiments described herein, the ILS is specifically refined along the first exposure edge 308 of the first exposure pattern 304.

[0061] The pattern deviation 314 of the second exposure pattern 306 and the first exposure pattern 304 is determined based on the lithography model 706. The lithography model 706 is operable to predict the position 320 and width 318 of the second exposure pattern 306, and to predict the pattern deviation 314 of the first exposure pattern 304. The lithography model is constructed and defined based on optical characteristics (e.g., optical characteristics associated with the maskless lithography apparatus 108) and photoresist characteristics (e.g., characteristics of the photoresist on which patterns will be printed, such as the material and processing characteristics of the photoresist).

[0062] After constructing the photolithography model, the digital pattern file 104 is input into the model. The model then predicts and adjusts variables to output predictions of the spatial image and photoresist outline of the digital pattern file 104. Through post-processing steps, the ILS and depth of focus based on the features formed by the digital pattern file 104 in the photoresist of the substrate can be determined. Variables include the width 318 and position 320 of the second exposure pattern 306 (e.g., ...). Figure 3A and 3B (as shown) and the pattern deviation value of the first exposure pattern 304 (such as) Figure 3B (As shown). Variables are predicted using a lithography model to increase the ILS and depth of focus, while maintaining the desired size of the first exposure pattern 304 and avoiding the printing of additional patterns.

[0063] The variables are adjusted according to the lithography model 706 or other rules of the double exposure software application 106 until the critical intensity log slope (ILS) and / or the depth of focus of the feature is reached. The lithography model 706 can also be considered. Additionally or alternatively, the double exposure software application 106 refines the digital pattern file 104 by adjusting the variables of the digital pattern file 104 according to the lithography model 706 or other rules of the double exposure software application 106 until the maximum intensity log slope (ILS) and / or the depth of focus of the feature is reached. In one implementation, which can be combined with other implementations described herein, the ILS is specifically refined along the first exposure edge 308 of the first exposure pattern 304.

[0064] The double exposure software application 106 can simultaneously predict the position 320 of the second exposure pattern 306, the width 318 of the second exposure pattern 306, and the pattern bias 314 within the double exposure software application 106. The double exposure software application 106 predicts the pattern bias 314 needed to maintain the critical dimension 312 of the first exposure pattern 304 based on the position 320 and the width 318 of the second exposure pattern 306.

[0065] The lithography model 706 ensures that the pattern bias 314 is determined such that the first exposure pattern 304 is within the desired pattern tolerance based on the digital pattern file 104. The lithography model 706 also ensures that the second exposure pattern 306 is confined within the first exposure pattern 304.

[0066] At operation 603, the first exposure pattern 304 with the pattern bias 314 is provided to the virtual mask software application 102. The virtual mask software application 102 converts the first exposure pattern 304 of the one or more polygons 302A-302C within the digital pattern file 104 into one or more quadrilateral polygons to generate a first virtual mask file. The first virtual mask file is a digital representation of the first exposure pattern 304 that will be printed by the maskless lithography device 108.

[0067] At operation 604, the first virtual mask file is provided to the maskless lithography device 108. The maskless lithography device 108 performs a lithography process to expose a substrate to the first exposure pattern included in the first virtual mask file. Optionally, after the lithography process at operation 404, the substrate can be further processed, for example by developing a photoresist and / or etching, to form a pattern on the substrate.

[0068] At operation 605, the second exposure pattern 306 is provided to the virtual mask software application 102. The virtual mask software application 102 converts the second exposure pattern 306 of the one or more polygons 302A-302C within the digital pattern file 104 into one or more quadrilateral polygons to generate a second virtual mask file. The second virtual mask file is a digital representation of the second exposure pattern 306 to be printed by the maskless lithography device 108.

[0069] At operation 606, the second virtual mask file is provided to the maskless lithography device 108. The maskless lithography device 108 performs a lithography process to expose the substrate to the second exposure pattern 306 included in the second virtual mask file. The second exposure pattern 306 is added to the first exposure pattern 304 to form a double exposure pattern (e.g., a double exposure pattern 300 of Figure 3A and 3B The addition of the first exposure pattern 304 and the second exposure pattern 306 increases the intensity log slope and the depth of focus of the features formed on the photoresist of the substrate. Thus, the resolution and process window of the maskless lithography device 108.

[0070] Figure 8 A processing system 800 according to certain embodiments is depicted. According to certain embodiments, the processing system 800 is an instance of the controller 110, and can be used in place of the controller 110 described above. Figure 8 An example processing system 800 is depicted, which can operate the systems described herein to perform embodiments of the methods according to the flowcharts and methods described herein, such as the method for performing rule-based double exposure as described with respect to Figure 4 and 5 and the method for performing model-based double exposure as described with respect to Figure 6 and 7

[0071] The processing system 800 includes a central processing unit (CPU) 802 connected to a data bus 816. The central processing unit 802 is configured to process computer-executable instructions, for example, stored in the memory 808 or the storage 810, and cause the processing system 800 to perform embodiments of the methods described herein with respect to, for example, the systems described herein with respect to Figures 1-7 The central processing unit 802 included is representative of a single central processing unit, multiple central processing units, a single central processing unit having multiple processing cores, and other architectures capable of executing computer-executable instructions.

[0072] ​The processing system 800 further includes an input / output (I / O) device 812 and interface 804 that allows the processing system 800 to communicate with one or more input / output devices 812, such as a keyboard, mouse, display, pen input, and other devices allowing interaction with a human user or other input / output devices. It should be noted that the processing system 800 can communicate with external input / output devices through an external interface (e.g., a universal serial bus (USB) interface) or an internal interface (e.g., a bus interface within the processing system 800).

[0073] The processing system 800 further includes a network 814 interface that provides the processing system with access to the external network 814, thereby providing access to the external computing devices.

[0074] The processing system 800 further includes a memory 808, which in this example includes the virtual mask software application 102 and the double exposure software application 106 for performing the operations described herein, such as the operations described in connection with Figure 4 and 6 The processing system 800 further includes a memory 808, which in this example includes the virtual mask software application 102 and the double exposure software application 106 for performing the operations described herein, such as the operations described in connection with

[0075] It should be noted that although a single memory 808 is shown in Figure 8 for simplicity, the various aspects stored in the memory 808 can be stored in different physical memories, including memories that are remote from the processing system 800, but all of which are accessible to the central processing unit 802 via internal data connections, such as the bus 816.

[0076] The storage 810 further includes substrate layout design data 828, chip set layout design data 830, digital exposure set data 832, displacement data 834, machine learning (ML) model data 836 (i.e., lithography model data), machine learning training data 838, lookup table data 840, and virtual mask data 842 for performing the operations described herein. Other data and aspects can be included in the storage 810 as will be appreciated by one of ordinary skill.

[0077] As with the memory 808, a single storage 810 is depicted in Figure 8 for simplicity, but the various aspects stored in the storage 810 can be stored in different physical storage, but all of which are accessible to the central processing unit 802 via internal data connections, such as the bus 816, or external connections, such as the network interface 806. It will be appreciated by those skilled in the art that one or more elements of the processing system 800 can be located remotely and accessed through the network 814.

[0078] The foregoing description is provided to enable any person skilled in the art to practice the various implementations described herein. The examples discussed herein are not limiting and are not intended to limit the scope of the claims appended hereto. Various modifications readily apparent to one skilled in the art, as well as other implementations and uses, will be readily achieved from the teachings set forth herein. For example, the functionality and arrangement of the described elements can be changed to suit particular applications. Various examples can omit, substitute, or add various procedures or components as appropriate. For instance, the methods described can be performed in an order different than that described, and / or various steps can be added, omitted, or combined. Also, features described with respect to certain examples can be combined in other examples. For example, any of the aspects set forth herein can be used alone or in combination with one another. Furthermore, the scope of the disclosure is intended to cover any and all such adaptations of the various implementations of the disclosure. Accordingly, the scope of the disclosure is intended to cover all such modifications and variations of the various implementations thereof in accordance with the intended scope of the following claims and their equivalents.

[0079] As used herein, the phrase“at least one of” a list of items refers to any combination of those items, including single members. For example,“at least one of a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any of the same elements in any order.

[0080] As used herein, the term“determining” encompasses a wide variety of actions. For example,“determining” can include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure), ascertaining, and the like. Also,“determining” can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), and the like. Also,“determining” can include resolving, selecting, choosing, establishing, and the like.

[0081] The methods disclosed herein include one or more operations or actions for implementing these methods. The method operations and / or actions may be interchanged without departing from the scope of the claims. In other words, unless a specific order of operations or actions is specified, the order and / or use of a particular operation and / or action may be modified without departing from the scope of the claims. Furthermore, the various operations of the above methods can be performed by any suitable means capable of performing the corresponding functions. These means may include various hardware and / or software components and / or modules, including but not limited to circuits, application-specific integrated circuits (ASICs), or processors. Typically, where operations are illustrated in the figures, these operations may have corresponding means plus functional components with similar numbering.

[0082] The claims below are not intended to limit the embodiments shown herein, but rather to conform to the full scope consistent with the language of the claims. In the claims, unless otherwise specified, the singular form of an element does not mean “one and only one,” but rather “one or more.” Unless otherwise specified, the term “some” means one or more. No element of a claim should be construed in accordance with 35 U.S.SC §112(f) unless it is expressly stated using the phrase “means for…” or, in the case of a method claim, using the phrase “steps for…”. All structural and functional equivalents of elements of the various aspects described in this disclosure that are known to or will become apparent later to a person skilled in the art are expressly incorporated herein by reference and are intended to be covered by the claims. Furthermore, the disclosure herein is not intended to be made public, whether or not it is expressly stated in the claims.

[0083] In summary, this paper describes a method for printing double exposure patterns in a photolithography environment. The method involves determining a second exposure pattern to be exposed using a first exposure pattern during the photolithography process. The second exposure pattern is determined by a rule-based processing flow or a photolithography model processing flow. Furthermore, deviations can be applied to the first exposure pattern to compensate for changes in critical dimensions of the first exposure pattern caused by the second exposure pattern. The double exposure pattern is formed using a double exposure pattern software application to improve the intensity logarithmic slope and depth of focus based on the characteristics of the double exposure pattern formed in the photoresist. Therefore, the double exposure pattern can be used to improve the resolution and process window of a maskless lithography apparatus used in the photolithography process. Since the double exposure pattern is a software-based solution, it can be used quickly and cost-effectively to improve resolution and process window.

[0084] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments can be devised without departing from the basic scope of the present disclosure, and the scope of the present disclosure is determined by the appended claims.

Claims

1. A method of printing a double-exposure pattern, comprising: receiving data defining a first exposure pattern for a lithography process, the first exposure pattern comprising one or more polygons; determining a position and a width of a second exposure pattern based on the data defining the first exposure pattern, wherein the second exposure pattern is confined within the first exposure pattern; determining a pattern bias to be applied to the first exposure pattern during the lithography process, the pattern bias of the first exposure pattern being determined based on the position and the width of the second exposure pattern; converting the data of the first exposure pattern and data indicative of the pattern bias into a first virtual mask file; patterning a substrate using the first virtual mask file in a maskless lithography device; converting data of the second exposure pattern into a second virtual mask file; and patterning the substrate using the second virtual mask file in the maskless lithography device. referred to a lookup table database comprising empirical data related to the first exposure pattern.

2. The method of claim 1, wherein the step of determining the position and the width of the second exposure pattern comprises:

3. The method of claim 2, wherein the lookup table database determines the position and the width of the second exposure pattern based on a maximum of one or both of an intensity log slope and a depth of focus of a feature formed in a photoresist of a substrate based on the data defining the first exposure pattern.

4. The method of claim 3, wherein the lookup table database determines the position and the width of the second exposure pattern such that the second exposure pattern is confined within the first exposure pattern.

5. The method of claim 1, wherein the step of determining the pattern bias comprises referring to a lookup table database comprising empirical data related to a bias for maintaining a predetermined critical dimension of the first exposure pattern.

6. The method of claim 1, further comprising processing the substrate by developing or etching the substrate to form a pattern on the substrate. converting each of the one or more polygons within the data into one or more quadrilateral polygons to produce the first virtual mask file.

7. The method of claim 1, wherein the step of converting the data of the first exposure pattern and the data indicative of the pattern bias into the first virtual mask file comprises: converting each of the one or more polygons within the data into one or more quadrilateral polygons to produce the second virtual mask file.

8. The method of claim 1, wherein the step of converting the data of the second exposure pattern into the second virtual mask file comprises:

9. The method of claim 1, wherein the pattern bias of the first exposure pattern is a negative bias.

10. A method of printing a double-exposure pattern, comprising: receiving data defining a first exposure pattern for a lithography process, the first exposure pattern comprising one or more polygons; inputting the data into a lithography model, the lithography model being constructed to predict aerial images and photoresist profiles based on the data; determining a position and a width of a second exposure pattern using numerical computation to solve the lithography model, wherein the second exposure pattern is confined within the first exposure pattern, and wherein the position and the width correspond to a maximum intensity log slope or a depth of focus of a feature formed in a photoresist of a substrate based on the data; ​ determining a pattern bias to be applied to the first exposure pattern during the lithography process, the pattern bias of the first exposure pattern being determined using numerical calculations to solve the lithography model, wherein the pattern bias corresponds to a maximum intensity log-slope or a depth of focus of the features formed in the photoresist of the substrate based on the data; converting the data of the first exposure pattern and data indicative of the pattern bias into a first virtual mask file; patterning a substrate using the first virtual mask file in a maskless lithography device; converting data of the second exposure pattern into a second virtual mask file; and patterning the substrate in the maskless lithography device using the second virtual mask file.

11. The method of claim 10, wherein the steps of determining the position of the second exposure pattern, the width of the second exposure pattern, and the pattern bias comprise: providing the data to the lithography model of a double exposure pattern software application, the double exposure pattern software application operable to simultaneously predict the position of the second exposure pattern, the width of the second exposure pattern, and the pattern bias.

12. The method of claim 11, wherein the double exposure pattern software application predicts the pattern bias required to maintain a critical dimension of the first exposure pattern based on the position and the width of the second exposure pattern.

13. The method of claim 10, further comprising processing the substrate by developing or etching the substrate to form a pattern on the substrate.

14. The method of claim 10, wherein the step of converting the data of the first exposure pattern and data indicative of the pattern bias into the first virtual mask file comprises: converting each of the one or more polygons within the data into one or more quadrilateral polygons to generate the first virtual mask file.

15. The method of claim 10, wherein the step of converting the data of the second exposure pattern into the second virtual mask file comprises: converting each of the one or more polygons within a data file into one or more quadrilateral polygons to generate the second virtual mask file.

16. A system for printing a double exposure pattern, comprising: a moveable platform configured to support a substrate having a photoresist disposed thereon; and a processing unit disposed on the moveable platform, the processing unit configured to print a first virtual mask file and a second virtual mask file provided by a controller in communication with the processing unit, wherein the controller is configured to: receive data defining a first exposure pattern of a lithography process, the first exposure pattern comprising one or more polygons; determine a position and a width of a second exposure pattern based on the data defining the first exposure pattern, wherein the second exposure pattern is confined within the first exposure pattern; determine a pattern bias to be applied to the first exposure pattern during the lithography process, the pattern bias of the first exposure pattern being determined based on the position and the width of the second exposure pattern; convert the data of the first exposure pattern and data indicative of the pattern bias into the first virtual mask file; patterning a substrate using the first virtual mask file with the processing unit; convert data of the second exposure pattern into the second virtual mask file; and patterning the substrate with the processing unit using the second virtual mask file. providing the data to the lithography model of a double exposure pattern software application, the double exposure pattern software application operable to simultaneously predict the position of the second exposure pattern, the width of the second exposure pattern, and the pattern bias.

12. The method of claim 11, wherein the double exposure pattern software application predicts the pattern bias required to maintain a critical dimension of the first exposure pattern based on the position and the width of the second exposure pattern.

13. The method of claim 10, further comprising processing the substrate by developing or etching the substrate to form a pattern on the substrate. converting each of the one or more polygons within the data into one or more quadrilateral polygons to generate the first virtual mask file. converting each of the one or more polygons within a data file into one or more quadrilateral polygons to generate the second virtual mask file.

16. A system for printing a double exposure pattern, comprising: a moveable platform configured to support a substrate having a photoresist disposed thereon; and a processing unit disposed on the moveable platform, the processing unit configured to print a first virtual mask file and a second virtual mask file provided by a controller in communication with the processing unit, wherein the controller is configured to: receive data defining a first exposure pattern of a lithography process, the first exposure pattern comprising one or more polygons; determine a position and a width of a second exposure pattern based on the data defining the first exposure pattern, wherein the second exposure pattern is confined within the first exposure pattern; determine a pattern bias to be applied to the first exposure pattern during the lithography process, the pattern bias of the first exposure pattern being determined based on the position and the width of the second exposure pattern; convert the data of the first exposure pattern and data indicative of the pattern bias into the first virtual mask file; patterning a substrate using the first virtual mask file with the processing unit; convert data of the second exposure pattern into the second virtual mask file; and patterning the substrate with the processing unit using the second virtual mask file.

17. The system of claim 16, wherein the controller is further configured to process the substrate by developing or etching the substrate to form a pattern on the substrate.

18. The system of claim 16, wherein the controller is further configured to reference a look-up table database comprising empirical data related to the first exposure pattern.

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