Method of forming planarization layer including exposing at different temperatures curable composition to actinic radiation

Abstract

To solve the problem that materials used for IAP may take a long time to form a cured planarization layer.SOLUTION: A system includes: a first actinic radiation exposure station including a first actinic radiation source; a superstrate removal tool; a second actinic radiation exposure station located remotely with respect to the first actinic radiation exposure station; and a controller. The second actinic radiation exposure station includes a second actinic radiation source and heating means for heating a photocurable composition. The controller activates the superstrate removal tool to remove after a first actinic radiation exposure within the first actinic radiation exposure station and before a second actinic radiation exposure within the second actinic radiation exposure station, and controls the heating means to heat the photocurable composition and a substrate to the actinic radiation exposure temperature. The system includes actinic radiation exposure at a first temperature and actinic radiation exposure at a second temperature that is greater than an ambient temperature and different from the first temperature.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a method of forming a planarization layer, including exposing a curable composition to actinic radiation at different temperatures.

Background Art

[0002] Inkjet-based adaptive planarization (IAP) is used in microelectronics manufacturing. As the dimensions of microelectronic components continue to decrease, processes including IAP become more difficult. The IAP process can include dispensing a photocurable composition onto a substrate and disposing a superstrate in contact with the photocurable composition. The IAP process can further include photocuring a layer of the photocurable composition by exposing the photocurable composition to actinic radiation to form a cured layer. Photocuring is performed at room temperature, for example, 20°C. The cured layer is then baked to form a baked planarization layer. The thickness of the baked planarization layer is thinner than the thickness of the curable composition. The change in thickness degrades the planarization performance of the baked planarization layer formed by the IAP process described above. The resulting surface of the baked planarization layer has a non-uniform topography having some regions at a locally low height and other regions at a locally high height. A planarization layer having no height difference or at least a small height difference across such a surface is desired.

[0003] The materials used in IAP can require substantially longer times to photocure to form a cured planarization layer compared to photocuring a pattern resist layer used in nanoimprint lithography (NIL). For example, a planarization layer formed using the IAP process can take several minutes for photocuring, while a pattern resist layer formed using the NIL process can be photocured in less than 1 second.

[0004] When forming a planarization layer using an IAP process, the cured polymer layer can be baked at a temperature in the range of 350 °C to 400 °C. Many materials used to form the cured polymer layer used in NIL cannot withstand baking and will decompose or be substantially adversely affected by the baking temperature. Therefore, many materials used in NIL are not suitable for use in the IAP process.

[0005] When forming a planarization layer, it is necessary to obtain a planarization layer with no or very little height difference across the surface while maintaining an acceptable throughput.

Summary of the Invention

Means for Solving the Problems

[0006] In one aspect, the method can include exposing a photocurable composition to first actinic radiation at a first temperature and exposing the photocurable composition to second actinic radiation at a second temperature to form a cured planarization layer, where the second temperature is higher than the ambient temperature and different from the first temperature.

[0007] In an embodiment, the method further includes dispensing the photocurable composition onto a substrate, and exposing the photocurable composition to the first actinic radiation is performed such that the photocurable composition is disposed between the substrate and a superstrate.

[0008] In a particular embodiment, the method further includes removing the superstrate after exposing the photocurable composition to the first actinic radiation and before exposing the photocurable composition to the second actinic radiation.

[0009] In another embodiment, exposing the photocurable composition to the first actinic radiation and exposing the photocurable composition to the second actinic radiation are performed such that the second temperature is higher than the first temperature.

[0010] In yet another aspect, the method further includes baking the cured planarization layer to form a baked planarization layer. Exposing the photocurable composition to the first actinic rays is performed at a first radiation dose, and exposing the photocurable composition to the second actinic rays is performed at a second radiation dose. The thermal shrinkage of the baked planarization layer is less than the thermal shrinkage of different baked planarization layers formed from the photocurable composition by exposing the photocurable composition to a single radiation dose at the ambient temperature and then baking at a baking temperature and a soak time, and the single radiation dose is the sum of the first radiation dose and the second radiation dose.

[0011] In certain embodiments, baking the cured planarization layer is performed at the baking temperature in the range of 300 °C to 500 °C and the soak time in the range of 1 minute to 60 minutes.

[0012] In yet another embodiment, the photocurable composition includes a polymerizable material containing an aryl group.

[0013] In certain embodiments, the polymerizable material includes vinylbenzene.

[0014] In a further embodiment, exposing the photocurable composition to the second actinic rays is performed in an environment containing up to 2 mol% of an oxygen-containing gas.

[0015] In another embodiment, exposing the photocurable composition to the first actinic rays is performed at a first radiation dose, exposing the photocurable composition to the second actinic rays is performed at a second radiation dose, and the first radiation dose is at most 30% of the sum of the first radiation dose and the second radiation dose.

[0016] In another aspect, the method is to expose the curable composition to a first actinic ray, wherein the photocurable composition is positioned between a substrate and a superstrate, remove the superstrate from the photocurable composition, and expose the photocurable composition to a second actinic ray to form a cured planarization layer. Removing the superstrate is performed after exposing the photocurable composition to the first actinic ray and before exposing the photocurable composition to the second actinic ray.

[0017] In an embodiment, the method further includes baking the cured planarization layer to form a baked planarization layer.

[0018] In a particular embodiment, baking the cured planarization layer is performed at a bake temperature of at least 300 °C and a soak time of at least 1 minute.

[0019] In a more particular embodiment, baking the cured planarization layer is performed at a maximum bake temperature of 500 °C and a maximum soak time of 60 minutes.

[0020] In another more particular embodiment, exposing the photocurable composition to the first actinic ray is performed at a first radiation dose, and exposing the photocurable composition to the second actinic ray is performed at a second radiation dose. The thermal shrinkage of the baked planarization layer is less than the thermal shrinkage of different baked planarization layers formed from the photocurable composition by exposing the photocurable composition to a single radiation dose at ambient temperature and then baking at the bake temperature and the soak time, and the single radiation dose is the sum of the first radiation dose and the second radiation dose.

[0021] In a further embodiment, exposing the photocurable composition to the first actinic ray is performed at a first temperature, exposing the photocurable composition to the second actinic ray is performed at a second temperature, and the second temperature is higher than the first temperature.

[0022] In a further embodiment, the system includes a first actinic radiation exposure station configured to emit first actinic radiation at a first wavelength of less than 700 nm to expose a photocurable composition disposed between a substrate and a superstrate, a superstrate removal tool for removing the superstrate from the photocurable composition, and a second actinic radiation exposure station disposed remotely from the first actinic radiation exposure station. The second actinic radiation exposure station can include a second actinic radiation source configured to emit second actinic radiation at a second wavelength of less than 700 nm to expose the photocurable composition to form a cured planarization layer, and heating means for heating the photocurable composition and the substrate to an actinic radiation exposure temperature. The apparatus can further include a controller configured to activate the superstrate removal tool to remove the superstrate after the first actinic radiation exposure in the first actinic radiation exposure station and before the second actinic radiation exposure in the second actinic radiation exposure station, and to control the heating means to heat the photocurable composition and the substrate to the actinic radiation exposure temperature that is higher than the ambient temperature.

[0023] In an embodiment, the system further includes a dispensing head configured to dispense the photocurable composition onto the substrate.

[0024] In another embodiment, the first unit includes the dispensing head, the superstrate removal tool, and the first actinic radiation exposure station, the second unit includes the second actinic radiation exposure station, and the second unit is spaced apart from the first unit and different from the first unit.

[0025] In a further embodiment, the system further includes a bake station configured to heat the cured planarization layer to form a baked planarization layer, and the bake station is configured to heat the substrate and the cured planarization layer to a bake temperature in the range of 300 °C to 400 °C.

Brief Description of the Drawings

[0026] The embodiments are shown by way of example and are not limited to the accompanying drawings.

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DETAILED DESCRIPTION OF THE INVENTION

[0027] The following description, in combination with the drawings, is provided to assist in understanding the teachings disclosed herein. The following discussion focuses on specific embodiments of the teachings. This focus is provided to assist in explaining the teachings and should not be construed as a limitation on the scope or applicability of the teachings.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent not described herein, many details regarding specific materials and processing acts are conventional and can be found in textbooks and other sources in the art.

[0029] Before explaining the details of systems and methods that can be used to achieve the advantages described herein, with reference to FIGS. 1 and 2 showing how the shape of a layer of photocurable composition changes during the process, the thickness changes due to the process and planarization performance will be described. The specific thicknesses and depths are provided to illustrate specific examples and do not limit the scope of the invention as defined in the appended claims.

[0030] FIG. 1 includes a cross-sectional view of a substrate 10, a layer 20 of photocurable composition (hereinafter, "pre-cured layer") before photocuring, and a portion of a superstrate 30 having a flat bottom surface. The substrate 10 includes features 12 and trenches 14 between the features 12. Dimension 16 corresponds to the depth of the trench 14 and, in this particular example, is 200 nm.

[0031] The upper surface of the pre-cured layer 20 of the photo-curable composition is flat because the photo-curable composition is a fluid that contacts the flat lower surface of the superstrate 30. Dimension 22 corresponds to the thickness of the pre-cured layer 20 between the feature 12 and the bottom surface of the superstrate 30. In this specific example, dimension 22 is 40 nm. Dimension 24 corresponds to the thickness of the pre-cured layer 20 between the lower surface of the trench 14 and the lower surface of the superstrate 30. Dimension 24 is the sum of dimension 16 (the depth of the trench 14) and dimension 22 (the thickness of the pre-cured layer above the feature 12). Dimension 24 can be determined using Equation 1 below. D 24 =D 16 +D 22 (Equation 1) Here, D 24 is dimension 24, D 16 is dimension 16, and D 22 is dimension 22.

[0032] When using the depth described for dimension 16 and the thickness described for dimension 22, D 24 = 200 nm + 40 nm = 240 nm.

[0033] When the pre-cured layer 20 is photo-cured, the monomers in the photo-curable composition polymerize to form a photo-cured planarization layer. During polymerization, covalent bonds are formed between the monomers in the photo-curable composition, and the atoms are attracted to each other, causing the photo-curable composition to shrink. After photo-curing, the photo-cured planarization layer is baked to form the baked planarization layer 40 in FIG. 2. Additional cross-linking occurs during baking, further shrinking the polymerized material. Also, some transitions and relaxations of the polymer may occur during baking. Reactions such as oxidation, decomposition, degradation of the material at high temperatures, or combinations thereof may occur. Furthermore, some evaporation may occur during the process, which may affect the thickness.

[0034] Coincidence, any or all of the above-described reactions, and evaporation contribute to shrinkage. FIG. 2 includes the substrate 10 and the bake flattening layer 40 after the super straight 30 is removed. In this particular example, the bake flattening layer 40 has a shrinkage of 5% (a change in thickness of -5%) compared to the pre-cured layer 20. Dimension 42 corresponds to the thickness of the bake flattening layer 40 over the feature 12, and dimension 44 corresponds to the thickness of the bake flattening layer 20 within and over the trench 14. Due to the -5% change in thickness, dimension 42 is 95% of dimension 22, and dimension 44 is 95% of dimension 24. Thus, dimension 42 is 38 nm and dimension 44 is 228 nm.

[0035] The upper surface of the pre-cured layer 16 is at the same height, but the bake flattening layer 40 has an upper surface with different regions at different heights. Dimension 48 corresponds to the height difference along the upper surface of the bake flattening layer 40 between (1) a portion of the bake flattening layer 40 over the feature 12 of the substrate 10 and (2) a portion of the bake flattening layer 40 over the trench 14. Dimension 48 can be determined using Equation 2 below. D 48 =D 42 -(D 44 -D 16 ) (Equation 2) Here, D 48 is dimension 48, D 42 is dimension 42, and D 44 is dimension 44.

[0036] When using the values of the dimensions, D 48 = 38 nm - (228 nm - 200 nm) = 10 nm.

[0037] Advanced manufacturing processes require that the change in thickness be 8 nm or less regardless of the depth of the trench 14. Thus, the 10 nm change in thickness corresponding to the substrate 10 and the bake flattening layer 40 in FIG. 2 may cause problems during subsequent processes when fabricating electronic devices. The change in thickness needs to be -4% or less in order to achieve 8 nm for dimension 48.

[0038] In this specification, the thickness change is between any two of (1) a pre-cured layer of the photocurable composition, (2) a partially cured planarization layer corresponding to the pre-cured layer, (3) a photocurable planarization layer corresponding to the partially cured planarization layer, or (4) a baked planarization layer corresponding to the photocurable planarization layer. Unless otherwise specified, the thickness change is expressed as a percentage.

[0039] The thickness change can be determined using the following Equation 3. ((T 2 - T 1 ) / T 1 ) * 100% (Equation 3) Here, T 1 is the thickness of the layer at a relatively earlier point in the process, and T 2 is the thickness of the layer at a relatively later point in the process.

[0040] For example, T 1 is the thickness of the pre-cured layer, and T 2 is the thickness of the photocurable planarization layer or the baked planarization layer. Also, T 1 is the thickness of the partially cured planarization layer, and T 2 is the thickness of the baked planarization layer. Negative values correspond to shrinkage, and positive values correspond to expansion. The thickness change is described in terms of how far the thickness change is from 0%. Thus, a thickness change of -4.0% may decrease to -1.0%, but literally, -4.0% is less than -1.0%.

[0041] Thickness measurements for determining thickness changes should be performed with the same thickness measurement tool at substantially the same location and surface features, such as on the convex portion, within the concave portion, and within the scribe lane between dies. The thickness measurements should be within a region of the substrate surrounded by an exclusion zone extending over a distance in the range of 1 mm to 9 mm, for example, 3 mm, from the periphery of the substrate towards the center. The thickness measurements are performed using an atomic force microscope (AFM), an interferometer, an ellipsometer, a profilometer, or any suitable instrument for measuring the thickness of a layer or the surface profile of a layer. As an alternative to thickness measurements, the difference in relative heights at two positions representing the flatness of the planarization layer may be measured. In an embodiment, a contour map may be generated from the upper surface of the layer, showing the height change across such a surface.

[0042] The thickness change can be the change in a single thickness, or the average of multiple thickness changes between pairs of thickness measurements, or the average from a contour map corresponding to the upper surface of a pre-cured layer, a partially cured planarization layer, a photo-cured planarization layer, or a baked planarization layer.

[0043] The method can include exposing the photocurable composition to a first actinic radiation at a first temperature and exposing the photocurable composition to a second actinic radiation at a second temperature to form a cured planarization layer. The second temperature is higher than the ambient temperature and different from the first temperature.

[0044] The method can be executed by a system. The system can include a first actinic radiation exposure station including a first actinic radiation source, a superstrate removal tool, a second actinic radiation exposure station disposed remotely from the first actinic radiation exposure station, and a controller. The first actinic radiation source can emit first actinic radiation at a first wavelength less than 700 nm and expose a photocurable composition disposed between a substrate and a superstrate. The superstrate removal tool can remove the superstrate from the photocurable composition. The second actinic radiation exposure station can include a second actinic radiation source and a heating means. The second actinic radiation source can emit second actinic radiation at a second wavelength less than 700 nm and expose the photocurable composition to form a photocured planarization layer. The heating means can heat the photocurable composition and the substrate to an actinic radiation exposure temperature. The controller can be configured to activate the superstrate removal tool to remove the superstrate after the first actinic radiation exposure in the first actinic radiation exposure station and before the second actinic radiation exposure in the second actinic radiation exposure station. The controller can be further configured to control the heating means to heat the photocurable composition and the substrate to an actinic radiation exposure temperature higher than the ambient temperature.

[0045] The method and system can help achieve a high production volume and prevent the thickness change between a pre-cured layer or a partially cured planarization layer of the photocurable composition and the corresponding baked planarization layer from being too large. In an embodiment, the substrate and the pre-cured layer can be exposed to the first actinic radiation source for a relatively short time in the first actinic radiation exposure station to form a partially cured planarization layer. The relatively short time helps achieve a high production volume. The partially cured planarization layer can be heated and exposed to the second actinic radiation source for a relatively long time in the second actinic radiation exposure station to help the thickness change be within an acceptable value.

[0046] The method is performed within system 300 of FIGS. 3 to 5 or within system 600 of FIG. 6. System 300, system 600, or both systems can further include a post-exposure bake apparatus 500 of FIG. 5 that can perform a bake operation. The system is suitable for an IAP process.

[0047] After reading this specification, one of ordinary skill in the art can determine the number of devices and their corresponding operations when designing a system. In the following description, system 300 of FIGS. 3 to 5 is described before system 600 of FIG. 6.

[0048] FIGS. 3 to 5 include conceptual diagrams of a system 300 that can be used to form a bake planarization layer from a photocurable composition on a substrate. System 300 can include a curing unit 301 that can be used to convert the photocurable composition into a partially cured planarization layer, another curing unit 303 that can be used to convert the partially cured planarization layer into a photocured planarization layer, and a post-exposure bake apparatus 500 that can be used to bake the photocured planarization layer into a bake planarization layer. Units 301 and 303 can be part of the same device or different devices. The photocurable composition is almost cured before baking. Some curing may occur during the post-exposure bake operation.

[0049] The curing unit 301 includes a substrate pod 321, a dispensing station 323, a radiation exposure station 326, a controller 350, and a memory 352. The dispensing station 323 can include a substrate chuck 333 that can be coupled to a stage (not shown) that enables the substrate chuck 333 to move between the station 323 and the station 326. The curing unit 303 includes a curing unit 370, a controller 390, and a memory 392. The curing unit 370 can include a substrate pod 371 and a radiation exposure station 376 that includes a substrate chuck 386. The baking apparatus 500 can include a substrate transfer tool 510, a baking unit 570, a controller 550, and a memory 552. The baking unit 570 can include a substrate pod 571 and one or more baking stations 576 each of which includes a substrate chuck 586.

[0050] Many of the components described above will be explained below with respect to the functions they perform. Details regarding the operation of the components, particularly the stations 323, 326, 376, and 576, will be explained in more detail later in this specification with respect to the method of using the system 300.

[0051] The substrate transfer tool 310 can be configured to transfer one or more substrates to, from, or between any of the substrate pod 321, the dispense station 323, the radiation exposure station 326, the radiation exposure station 376, and the substrate pod 371. The substrate transfer tool 510 can be configured to transfer one or more substrates to, from, or between any of the substrate pod 571 and the bake station 576. The substrate transfer tools 310 and 510 may be or include one or more components of an EFEM (Equipment Front End Module). The components of the EFEM can include one or more of each of a robot arm, a robot hand adapted to hold a substrate, a sensor, a motor for moving the robot arm, another motor for moving the robot arm, etc. The robot arm can be configured to move a substrate with layers between stations, for example, from the dispense station 323 to the radiation exposure station 326. In an embodiment, a particular substrate and a superstrate may have the same shape and size. The substrate transfer tool 310 may be the same as or different from the substrate transfer tool 510.

[0052] Referring to FIGS. 3 to 5, the substrate pods 321, 371, and 571 can hold a plurality of substrates. The substrate is taken out from the substrate pod 321, processed at a station of the system 300 such as the stations 323, 326, 376 or a combination thereof, and can be moved to the substrate pod 371 or another substrate pod when the process in a part of the system 300 shown in FIG. 3 is completed. The substrate is taken out from the substrate pod 571, processed at one or more of the bake stations 576, and can be returned to the substrate pod 571 or another substrate pod when the baking is completed.

[0053] The dispensing station 323 can be configured to receive a substrate and dispense a photocurable composition onto the substrate. When the substrate is on the substrate chuck 333, the dispensing head 346 can be used to dispense the photocurable composition onto the substrate. The dispensing head 346 can include one or more nozzles for dispensing the photocurable composition. The dashed line within the dispensing head 346 is used to indicate that the photocurable composition is dispensed along the lower surface of the dispensing head 346. The stage coupled to the substrate chuck 333, the dispensing head 346, or both can be configured to move when dispensing the photocurable composition. Further details regarding the photocurable composition and methods of dispensing and processing the photocurable composition are described hereinbelow. The stage coupled to the substrate chuck 333 can transport the substrate and the photocurable composition thereon from the dispensing station 323 to the actinic radiation exposure station 326.

[0054] When the supersstrate has not yet contacted the photocurable composition, the supersstrate is placed in contact with droplets of the photocurable composition to coalesce the droplets of the photocurable composition and form a pre-cured layer of the photocurable composition. The supersstrate can be placed in contact with the droplets when the substrate is within the actinic radiation exposure station 326 or the dispensing station 323.

[0055] The chemical ray exposure station 326 can be configured to partially cure the photocurable composition. The preliminary cured layer of the photocurable composition can be exposed to chemical rays when the preliminary cured layer is at room temperature. The environmental temperature is the temperature in the room where the station for performing photocuring is arranged within the apparatus. Therefore, the environmental temperature can be the room temperature. For example, the environmental temperature may be in the range of 20°C to 25°C. The chemical rays can polymerize the polymerizable material in the photocurable composition to form a partially cured and planarized layer. The partially cured and planarized layer indicates a layer of the polymerized photocurable composition that is sufficiently photocured to enable the photosensitive layer to remove the superstrate, but is insufficiently cured for baking. The superstrate can be removed when the chemical ray exposure operation in the chemical ray exposure station 326 is completed. The photocurable composition can contain an internal release agent remaining in the partially cured and planarized layer after polymerization. The internal release agent can help reduce the likelihood of damaging or removing part or all of the partially cured and planarized layer when removing the superstrate. The substrate transfer tool 310 can transfer the substrate and the partially cured and planarized layer to one of the chemical ray exposure station 326 and the heated chemical ray exposure station 376.

[0056] The heated chemical ray exposure station 376 can be configured to perform two operations. The heated chemical ray exposure station 376 can be configured to heat the partially cured and planarized layer, expose the partially cured and planarized layer to chemical rays, and further cure the partially cured and planarized layer to form a photocured and planarized layer. Heating the substrate and the partially cured and planarized layer can be performed before exposure to the chemical rays in the station 376, or before and during exposure to the chemical rays, to form a photocured and planarized layer. In another embodiment, heating and exposure to chemical rays can be performed at two different stations when the heating is completed before exposure to the chemical rays. Sufficient thermal shielding is used to help prevent the heat from the heated chemical ray exposure station 376 from adversely affecting the operation of other parts of the system 300, such as the curing unit 301.

[0057] The heating means including the heat chemical ray exposure station 376 can be activated to heat the photocurable composition. Further details regarding the heating means of the heat chemical ray exposure station 376 will be described later in this specification. Direct temperature measurement of the partially cured planarization layer is difficult to obtain. Therefore, the temperature of the partially cured planarization layer can correspond to different temperatures within the heat chemical ray exposure station 376. The temperature of the partially cured planarization layer can be correlated with the corresponding substrate chuck 386, the substrate on such a substrate chuck 386, or, if present, the temperature of the superstrate in contact with the partially cured planarization layer. Since direct temperature measurement of the partially cured planarization layer may not be practical for the user of the system 300, the operation can be controlled using the temperature of the substrate chuck 386, the substrate, or, if present, the superstrate.

[0058] When the temperature of the substrate chuck 386, the substrate or the superstrate is within the target temperature or the allowable range of such a temperature, the heating means may be deactivated or maintained in a holding state to keep the substrate chuck 386 or the substrate within the target chemical ray exposure temperature or the allowable range of such a temperature. Such an allowable range of temperature is + / 5°C, 2°C, 1°C or 0.5°C of the target temperature. The target temperature may be the same as or different from the desired chemical ray exposure temperature when exposing the partially cured planarization layer to the chemical rays. The target temperature can be determined after the desired chemical ray exposure temperature is known. Further details regarding the target temperature will be described with respect to the method of using the system 300.

[0059] When the partially cured planarization layer is at the chemical ray exposure temperature, the partially cured planarization layer can be exposed to the chemical rays to form a photocured planarization layer. The chemical rays can further polymerize the polymerizable material within the photocurable composition. The photocured planarization layer refers to the layer of the photocurable composition after the partially cured planarization layer of the photocurable composition is photocured using the chemical rays and before the layer of the polymerized photocurable composition is further processed during the post-exposure bake operation.

[0060] Figures 3 and 4 include a top view of system 300 and a cross-sectional view of curing station 376 and substrate pod 371 on base housing 403. Controller 390 and memory 392 (FIG. 3) may be disposed within base housing 403 (FIG. 4). The configuration of curing station 376 may be planar such that curing station 376 is disposed along a single plane, may be stacked as shown in FIG. 4, or may be a combination of curing stations 376 disposed along a single plane and another combination of curing stations 376 that are stacked. Stacking the curing stations 376 can help reduce the area occupied by curing unit 303. The number of curing stations 376 within a stack is two or more. Due to the height constraints of the room in which curing unit 303 is disposed and the height of each curing station, the number of curing stations 376 within a stack is limited to nine stations, seven stations, or five stations. The number of stacks may be one or more. The number of stacks is limited by the available floor space in the room in which the curing unit is disposed. The number of stacks of curing stations 376 is limited to nine stacks, seven stacks, or five stacks. FIG. 4 shows two stacks to allow for redundancy of the apparatus without overly occupying the area of the room in the event that one of the stacks is unavailable.

[0061] Referring to FIG. 5, the post-exposure bake unit 570 can include a substrate pod 571 and a post-exposure bake station 576 including a substrate chuck 586. The post-exposure bake station 576 can further polymerize or crosslink the photocurable composition in the photocurable planarization layer by thermal curing, cause different reactions of the components in the photocurable composition, and drive out volatile components in the photocurable composition. The post-exposure bake station 576 can have any design including heating means, as described with respect to the heat ray exposure station 376. The heating means of the post-exposure bake station 576 may be the same as or different from the heating means of the heat ray exposure station 376. In an embodiment, the post-exposure bake station 576 can include heating means configured to operate at a higher temperature compared to the heat ray exposure station 376. The temperature used for the post-exposure bake may be at least 300°C. The highest process temperature associated with the post-exposure bake station 576 may be 500°C.

[0062] The above-described operations performed by any particular station may be moved or combined with another station. For example, dispensing at room temperature and exposure to actinic rays can be performed within the same station. In another configuration, the operations performed by one station may be performed at a separate station. For example, heating of the partially cured planarization layer may be performed at one station, and exposure of the heated partially cured planarization layer to actinic rays may be performed at a different station.

[0063] The substrate chucks 333, 386, and 586 may be vacuum chucks, pin-type chucks, groove-type chucks, electrostatic chucks, electromagnetic chucks, etc. The substrate chucks 333, 386, and 586 may be of the same type, for example, vacuum chucks, or of different types. For example, one of the substrate chucks may be a vacuum chuck, and another one of the substrate chucks may be an electrostatic chuck or an electromagnetic chuck. Each of the substrate chucks 333, 386, and 586 may or may not have a heating element, a cooling element, or both, which are used to heat or cool the substrate and the layer, and, if present, the superstrate on the substrate.

[0064] The controller 350 is coupled to the memory 352 and can control the curing unit 301. The controller 390 is coupled to the memory 392 and can control the unit 303. The controller 550 is coupled to the memory 552 and can control the baking apparatus 500. The controller 350 and the memory 352 will be described in more detail below. Except when describing the specific details of the system 300, the description of the controller 350 can be applied to the controllers 390 and 550, and the description of the memory 352 can be applied to the memories 392 and 552.

[0065] If necessary or desired, any combination of the controllers 350, 390, and 550 can communicate with each other. For example, one or both of the controllers 350 and 550 can be used to confirm that a particular lot of substrates having a photo-curable planarization layer in the substrate pod 571 has been processed within the unit 303 before the substrate and the photo-curable planarization layer are baked at the post-exposure baking station 576 in the unit 570.

[0066] Controllers 350, 390, and 550 can optionally operate using a computer-readable program stored in memory 352. Any or all of controllers 350, 390, and 550 can include a processor (e.g., a central processing unit of a microprocessor or microcontroller), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), etc. Controllers 350, 390, and 550 may be within system 300. In another embodiment of the system (not shown), any one or more of controllers 350, 390, and 550 may be at least part of a computer external to system 300, and such a computer is bidirectionally coupled to system 300.

[0067] Any or all of memories 352, 392, and 552 can include a non-transitory computer-readable medium containing instructions related to operations or for performing operations between operations. Any or all of memories 352, 392, and 552 can include a set of registers, cache memory, flash memory, a hard drive, etc. Any or all of memories 352, 392, and 552 can be accessed by any one or more of controllers 350, 390, and 550 to assist in determining operating parameters such as the local areal density of the photocurable composition to be dispensed, the target temperature, the actinic radiation exposure temperature, the dose of actinic radiation during one or more actinic radiation exposures, the total dose of actinic radiation received by the photocurable composition for all actinic radiation exposures, the post-exposure bake temperature, or other parameters used in the methods described below, and can further include a data table. As used herein, the total dose is the sum of the doses used when exposing the photocurable composition to actinic radiation. In an embodiment, the total dose can be the sum of the dose used to form a partially cured planarization layer and another dose used to form a more fully photocured planarization layer.

[0068] In another implementation, one or more components of the system 300, such as stations 323, 326, 376, and 576, can include local controllers that provide some of the functionality provided by controllers 350, 390, or 550.

[0069] For system 300, more or fewer controllers and more or less memory are used. In another embodiment, a single controller can perform all of the functions described with respect to controllers 350, 390, and 550. Thus, instead of three controllers, one controller is used for system 300. In a further embodiment, controller 350 can control curing units 301 and 303, and thus, controller 390 is not needed, or controller 390 can control curing units 301 and 303, and thus, controller 350 is not needed. In another embodiment, instead of three memories, a single memory is used for system 300. In a further embodiment, memory 352 is used with respect to curing units 301 and 303, and thus, memory 392 is not needed, or memory 392 is used with respect to curing units 301 and 303, and thus, memory 352 is not needed.

[0070] FIG. 6 includes a system 600 that includes curing units 601 and 303 in a single device, in contrast to the different devices in FIG. 3. The system includes a substrate transfer tool 610 disposed between curing unit 601 and curing unit 303. The substrate transfer tool 610 can perform any function, as described above with respect to substrate transfer tool 310. The substrate transfer tool 610 allows for a sufficient distance between curing unit 601 and curing unit 303 and can reduce the heat transferred from curing unit 303 to curing unit 601, particularly to the actinic exposure station 326 that operates at room temperature. System 600 further includes a controller 650 and a memory 652 that performs the functions described above with respect to controllers 350 and 390, and memories 352 and 652. System 600 can further include the post-exposure bake apparatus 500 in FIG. 5. Controller 650 and memory 652 can each be of any of the types described with respect to controllers 350 and 390, and memories 352 and 392.

[0071] Attention is drawn to a method of forming a baked planarization layer on a substrate using system 300. FIG. 7 includes a process flow chart of the method described with respect to FIGS. 3-5, 8-11, and 13-17. The process flow chart is also applicable to system 600 in FIG. 6 with respect to curing units 301 and 303 in FIGS. 3 and 4. A particular process flow is described below in connection with the drawings and is directed to the IAP process. Many different process flows can be used and benefits can be achieved using the concepts described herein. Hereinafter, an unpatterned superstrate is referred to as a blank and a patterned superstrate is referred to as a template. Other variations from the process flow are described later herein.

[0072] Referring to FIG. 3, the method can include transporting a substrate from substrate pod 321 to dispense station 323. Controller 350 or a local controller can send a signal for substrate transfer tool 310 to pick up the substrate from substrate pod 321 and move the substrate to dispense station 323. Substrate transfer tool 310 can place the substrate on substrate chuck 333 within dispense station 323.

[0073] The method can include dispensing a photocurable composition onto the substrate at block 722 in FIG. 7. The photocurable composition can include a polymerizable material and a photoinitiator. The photocurable composition may or may not include a solvent. In a further embodiment, the photocurable composition can contain other additives. Non-limiting examples of other additives are surfactants, dispersants, stabilizers, inhibitors, dyes, or combinations thereof.

[0074] The polymerizable material can include a single monomer compound or a mixture of monomer compounds. In an embodiment, the polymerizable material can include a polyfunctional monomer. The polyfunctional monomer in the photocurable composition can constitute a majority of the photocurable composition on a weight percentage basis. In one embodiment, the amount of the polyfunctional monomer in the photocurable composition is at least 60% by weight, or at least 70% by weight, or at least 80% by weight, or at least 90% by weight, or at least 92% by weight, or at least 95% by weight, based on the total weight of the photocurable composition. In another embodiment, the amount of the polyfunctional monomer is at most 99.5% by weight, for example, at most 99% by weight, or at most 98% by weight, or at most 97% by weight, or at most 95% by weight, or at most 93% by weight, or at most 90% by weight, based on the total weight of the photocurable composition. Further, the amount of the polyfunctional monomer is within a range including any of the above minimum and maximum values, for example, within a range of 60% by weight to 99.5% by weight, 70% by weight to 99% by weight, 80% by weight to 98% by weight, or 90% by weight to 97% by weight, based on the total weight of the photocurable composition.

[0075] In one embodiment, the polyfunctional monomer is a difunctional monomer, a trifunctional monomer or a tetrafunctional monomer. The functional group can be, among other possibilities, a vinyl group, an acrylate group, an acrylamide group, a methacrylate group, a maleimide group, an epoxy group, a lactone group, an acetal group, a cyclic ether group, a lactam group, a hydroxyl group, a carboxyl group, a sulfide group or an amine group. The polyfunctional monomer compound can include the same type of functional group (for example, all the functional groups in the polyfunctional monomer compound are vinyl groups) or different types of functional groups. In an embodiment, the polyfunctional monomer can include a polyfunctional acrylate monomer, a polyfunctional vinyl monomer or a combination thereof.

[0076] In certain embodiments, the multifunctional monomer can include at least two acrylate groups, or at least three or at least four acrylate groups. As used herein, the term "acrylate monomer" relates to substituted and unsubstituted acrylate monomers. Non-limiting examples of substituted acrylate monomers are C 1 -C 8 alkyl acrylates such as methacrylate or ethyl acrylate.

[0077] In another embodiment, the multifunctional monomer can include at least two, or at least three, or at least four vinyl groups.

[0078] In embodiments, the multifunctional monomer can include both acrylate groups and vinyl groups. In another embodiment, the multifunctional monomer can further include one or more aromatic ring structures.

[0079] Another multifunctional monomer can include two or more vinyl groups and at least one aromatic ring structure, such as one or more benzene rings. In embodiments, the multifunctional monomer can include vinylbenzene or divinylbenzene compounds. In certain embodiments, the multifunctional monomer is a biphenyl or diphenylmethane compound containing 2, 3 or 4 vinyl groups.

[0080] Table 1 below includes a list of exemplary multifunctional monomer compounds that can be used as polymerizable materials in the photocurable composition. The list is exemplary and not exhaustive and is not intended to limit the polymerizable material compounds that can be used. Table 1 includes Chemical Abstracts Service Registry Numbers (CAS) where applicable.

[0081]

Table 1

[0082] The photoinitiator can include a single photoinitiator compound or a mixture of photoinitiator compounds. In the same or another embodiment, the photoinitiator compound is an oxime ester compound. The oxime ester compound can have the structure of formula (1).

[0083]

Chemical formula

[0084] Here, R 1 is an aromatic ring system or a heteroaromatic ring system, and R 2 is H or C 1 -C 8 alkyl, and R 3 is H or C 1 -C 8 alkyl.

[0085] In certain embodiments, the photoinitiator of the photocurable composition can further include a photoinitiator compound that is not an oxime ester compound.

[0086] Table 2 below includes a list of exemplary photoinitiator compounds that can be used in the photocurable composition. The list is exemplary and not comprehensive and is not intended to limit the photoinitiator compounds that can be used.

[0087]

Table 2

[0088] Irgacure compounds are available from BASF SE in Ludwigshafen am Rhein, Germany. Omnirad is available from the IGM group in Waalwijk, the Netherlands.

[0089] The amount of the photoinitiator in the photocurable composition is at least 1.0% by weight, at least 1.5% by weight, at least 2.0% by weight, at least 2.5% by weight, at least 3.0% by weight, at least 3.5% by weight, or at least 4.0% by weight based on the total weight of the photocurable composition. In another aspect, the amount of the photoinitiator in the photocurable composition is at most 10.0% by weight, at most 8.0% by weight, at most 7.0% by weight, at most 6.0% by weight, at most 5.0% by weight, or at most 4.0% by weight based on the total weight of the photocurable composition. The amount of the photoinitiator in the photocurable composition is a value between any of the above minimum and maximum numbers, for example, a value in the range of 1.0% to 10.0% by weight, 1.5% to 8.0% by weight, or 2.0% to 7.0% by weight based on the total weight of the photocurable composition.

[0090] In embodiments, the photocurable composition may essentially contain no solvent. As used herein, unless otherwise indicated, the term "solvent" relates to a compound that can dissolve or disperse the polymerizable material but does not itself polymerize during exposure of the photocurable composition to actinic radiation. The phrase "essentially solvent-free" means herein an amount of solvent that is at most 5% by weight based on the total weight of the photocurable composition. In certain embodiments, the amount of the solvent is at most 3% by weight, at most 2% by weight, at most 1% by weight based on the total weight of the photocurable composition, or alternatively, the photocurable composition can be solvent-free except for unavoidable impurities.

[0091] In another embodiment, the photocurable composition can include a solvent in an amount exceeding 5% by weight based on the total weight of the photocurable composition. In certain aspects, the amount of the solvent is at least 10% by weight based on the total weight of the photocurable composition, or at least 15% by weight, at least 20% by weight, or at least 25% by weight based on the total weight of the photocurable composition. In another aspect, the amount of the solvent is at most 40% by weight, at most 30% by weight, at most 20% by weight, or at most 10% by weight based on the total weight of the photocurable composition. In a particular embodiment, the amount of the solvent in the photocurable composition is a value between any of the above minimum and maximum numbers, for example, in the range of 5% to 40% by weight, 10% to 30% by weight, or 15% to 20% by weight based on the total weight of the photocurable composition.

[0092] The surfactant can include a single surfactant compound or a mixture of surfactants. The surfactant compound is a fluorine-containing compound, and in an embodiment, the surfactant compound is a fluoro-organic compound. Table 3 below includes a list of exemplary surfactant compounds that can be used in the photocurable composition. This list is exemplary and not comprehensive and is not intended to limit the surfactant compounds that can be used.

[0093] [Table 3]

[0094] Capstone (trademark) FS-3100 is available from The Chemours Company of Wilmington, DE, USA.

[0095] The surfactant is at most 5.0% by weight based on the total weight of the photocurable composition. In a particular embodiment, the amount of the surfactant is at most 3.0% by weight, at most 2.0% by weight, or at most 0.9% by weight based on the total weight of the photocurable composition.

[0096] The photocurable composition is then polymerized to form a photocurable planarization layer, which is then baked at a temperature of at least 300°C. Therefore, the components and amounts of the components of the photocurable composition are selected so that the resulting photocurable planarization layer can withstand the baking operation without being substantially adversely affected by the baking operation.

[0097] Method, and returning to FIGS. 3 and 8, the dispensing head 346 dispenses droplets 822 of the photocurable composition onto the exposed surface of the substrate 802, as shown in FIG. 8. During the dispensing operation, the substrate chuck 333 can be coupled to a stage configured to move the substrate chuck 333 (indicated by the arrow adjacent to the substrate 802 in FIG. 8) during the dispensing operation. In another embodiment, the dispensing head 346 moves while the substrate chuck 333 is stationary, and in a further embodiment, both the substrate chuck 333 and the dispensing head 346 move during dispensing. Accordingly, the substrate 802 can move and the dispensing head 346 can be stationary or moving.

[0098] The substrate 802 can have an exposed surface having protrusions located at a relatively high height compared to adjacent recesses. In FIG. 8, the exposed surface of the substrate 802 has protrusions 8022 and recesses 8024. The substrate 802 has a local region with a relatively high surface density of the protrusions 8022 compared to the recesses 8024, and another local region with a relatively high surface density of the recesses 8024 compared to the protrusions 8022. A lower surface density of the photocurable composition is dispensed, and the protrusions 8022 occupy a relatively large proportion of the local region, and a higher surface density of the photocurable composition is dispensed, and the recesses 8024 occupy a relatively large proportion of a different local region. In practice, the exposed surface of the substrate 802 is considerably more complex than that shown in FIG. 8 and is not limited to only two heights. The exposed surface of the substrate 802 in FIG. 8 is simplified to assist in the understanding of the concepts described herein.

[0099] The controller 350 or the local controller can send signals for the dispensing head 346, the stage coupled to the substrate chuck 333 (when the substrate chuck 333 is coupled to the stage), or both to move in a desired direction and speed. The dispensing head 346 dispenses the droplets 822 of the photocurable composition at a desired speed to achieve an appropriate local area density of the photocurable composition along the exposed surface of the substrate 802.

[0100] Referring to FIGS. 3, 8, and 9, the stage coupled to the substrate chuck 333 can transport the substrate 802 and the droplets 822 of the photocurable composition from the dispensing station 323 to the actinic exposure station 326. The controller 350 or the local controller can send a signal to the stage for moving the substrate chuck 333, the substrate 802, and the droplets 822 of the photocurable composition from the dispensing station 323 to the actinic exposure station 326. The actinic exposure station 326 can include a super straight handler, a planarization head (not shown), or both.

[0101] The process further includes contacting the photocurable composition with the super straight at block 724 in FIG. 7. Referring to FIG. 9, the super straight 922 can help form a pre-cured layer from the droplets 822 of the photocurable composition. In an implementation, the super straight 922 can be a blank having a flat lower surface facing the substrate 802 and the droplets 822. The curing unit 301 can include a super straight handler (not shown) that can be used to move and position the super straight 922. In the same or a different embodiment, the super straight 922 can be held by a planarization head within the actinic exposure station 326.

[0102] Superstrate 922 has a transmittance of at least 70%, at least 80%, at least 85% or at least 90% with respect to actinic rays used to photocure the photocurable composition. Superstrate 922 can include a glass-based material, silicon, an organic polymer, a siloxane polymer, a fluorocarbon polymer, sapphire, spinel, another similar material or any combination thereof. The glass-based material can include soda lime glass, borosilicate glass, alkali barium silicate glass, aluminosilicate glass, quartz, fused silica, etc. In an embodiment, the actinic rays can be ultraviolet rays, and the glass-based material can be used for Superstrate 922. Superstrate 922 can have a thickness in the range of 30 microns to 2000 microns. The contact surface of Superstrate 922 can have a surface area that is at least 90%, 95%, 96%, 97% or 99% of the area of the substrate 802, and can have the same or a larger surface area than the substrate 802.

[0103] The contact surface of Superstrate 922 has a two-dimensional shape such as a circle, an ellipse, a rectangle (including a square), a hexagon, etc. The two-dimensional shape may be the same as the outer shape of the substrate 802. For example, both may be a circle. In the embodiment shown in FIG. 9, the contact surface has no recesses and protrusions.

[0104] Referring to FIGS. 3, 9 and 10, the controller 350 or the local controller can send a signal for Superstrate 922 and the droplet 822 to approach and contact each other. Superstrate 922 is moved, the substrate chuck 333 is moved, or both Superstrate 922 and the substrate chuck 333 are moved. When Superstrate 922 contacts the droplet 822 of the photocurable composition, the droplets 822 coalesce to form a pre-cured layer 1002 of the photocurable composition. The upper surface 1012 of the pre-cured layer 1002 coincides with the lower surface which is the contact surface of Superstrate 922.

[0105] The method can include exposing the photocurable composition to actinic radiation at a relatively low temperature in block 742 in FIG. 7 to form a partially cured planarization layer. In an embodiment, the relatively low temperature may be room temperature. Referring to FIG. 3, for a particular photocurable composition, the memory 352 can include information regarding the target wavelength or target wavelength range of the actinic radiation, the target dose or target dose range used for the photocurable composition, or other data related to exposing the photocurable composition to actinic radiation. Such information is used by the controller 350 or a local controller to determine parameters for exposing the photocurable composition to actinic radiation. The controller 350 can access empirical data previously collected using other substrates. The controller 350 can provide the desired actinic radiation exposure temperature for a particular photocurable composition, the bake temperature used during the post-exposure bake, the dose of actinic radiation used to photocure the pre-cured layer 1002, or a combination thereof. The temperature during exposure to actinic radiation is herein referred to as the actual actinic radiation exposure temperature. The actual actinic radiation exposure temperature can be the desired actinic radiation exposure temperature or in the vicinity thereof. The actual actinic radiation exposure temperature can be either the target temperature and tolerance described above.

[0106] Referring to FIGS. 3, 10, and 11, the controller 350 or a local controller can receive a signal from a temperature sensor or the derivative of such a signal and determine whether the temperature is within the tolerance (e.g., + / −5° C., + / −2° C., + / −1° C., or + / −0.5° C.) of the desired actinic radiation exposure temperature or within that range. The pre-cured layer 1002 is exposed to actinic radiation when the pre-cured layer 1002 is at room temperature. When the temperature is within the desired actinic radiation exposure temperature or tolerance range, the controller 350 or a local controller can transmit a signal for the actinic radiation source 1132 to be activated, as shown in FIG. 11. Each triangular symbol within the actinic radiation source 1132 can represent an individual radiation source, such as a UV lamp.

[0107] Actinic rays are emitted from an actinic ray source 1132. At least 70% of the actinic rays reaching the super straight 922 pass through the super straight 922. The actinic rays that have passed through the super straight 922 activate photoinitiators in the photocurable composition in the pre-cured layer 1002 to assist in the polymerization of the polymerizable material in the photocurable composition. The actinic rays can have a wavelength of at least 10 nm and less than 700 nm. The actinic rays may be ultraviolet rays having a wavelength in the range of 100 nm to 400 nm, more specifically, in the range of 200 nm to 400 nm. A supplier of the photocurable composition can provide a target wavelength or a target wavelength range used to photocure the photocurable composition.

[0108] The energy from the exposure to actinic rays forms a partially cured planarizing layer 1102 (FIG. 11) from the pre-cured layer 1002 (FIG. 10). The partially cured planarizing layer 1102 has an upper surface 1112. The energy polymerizes the polymerizable material to form a polymer material. The polymer material may be a single polymer compound or a copolymer. The partially cured planarizing layer 1102 is further polymerized during subsequent heat-actinic ray exposure operations.

[0109] In an embodiment, the superstrate 922 is removed, and the evaporation loss from the partially cured planarization layer 1102 becomes significant during subsequent heat and actinic exposure operations. At a low dose of the first exposure, unreacted monomers can remain, and at least a portion of them can evaporate during subsequent heat exposure. When a higher dose of the first exposure is used, most of the monomers are at least partially polymerized and do not easily evaporate during subsequent heat exposure. However, a high dose takes a long time to complete and reduces the overall throughput. Thus, there is a trade-off between the first exposure time and the evaporation loss. Reducing the evaporation loss is important because it affects the planarization performance. To demonstrate how the dose affects the evaporation loss, the partially cured planarization layer was prepared with different first exposure doses. After removing the superstrate, each sample was baked on a hot plate at 50 °C for 10 minutes. FIG. 12 includes a plot of the evaporation loss as a function of the dose used to form the partially cured planarization layer 1102. The evaporation loss is defined as the change in the relative thickness of the partially cured planarization layer before and after heating at 50 °C for 10 minutes. As the dose of the partially cured planarization layer 1102 increases, the amount of evaporation loss decreases. However, a larger dose adversely affects the throughput of the curing unit 301.

[0110] The dose when forming the partially cured planarization layer 1102 is affected by whether the superstrate 922 is removed before the subsequent process. If the partially cured planarization layer 1102 is not sufficiently cured, the partially cured planarization layer 1102 may be distorted or damaged when removing the superstrate 922. In an embodiment, at a dose of less than 1 J / cm 2 the partially cured planarization layer 1102 may not be sufficiently cured to enable a repeatable removal process used in manufacturing.

[0111] Referring to FIG. 12, at 3 J / cm 2At a dose of, the evaporation loss is less than 1%, and the superstrate 922 is removed from the partially cured planarization layer 1102 without significantly damaging the partially cured planarization layer 1102. However, the time required to achieve the dose may be too long for a mass production process. 2 J / cm 2 At a dose of 2 , the evaporation loss is approximately 1.2%, and the superstrate 922 is removed from the partially cured planarization layer 1102 without significantly damaging the partially cured planarization layer 1102. The time required to achieve the dose may still be unacceptably long. 1.5 J / cm 2 The dose of 2 has an acceptable process time. If higher evaporation losses are acceptable and the superstrate removal process is sufficiently reproducible, a dose of 1.5 J / cm 2 can be used.

[0112] In another embodiment, the superstrate 922 may not be removed after performing actinic exposure to form the photocured planarization layer. In this embodiment, the evaporation loss is substantially reduced, and damage associated with removing the superstrate 922 from the insufficiently cured layer is avoided. If the substrate is removed before further exposure to actinic rays, the superstrate 922 may not be removed until further photocuring occurs, and an evaporation loss, damage to the partially cured planarization layer 1102, or both may be acceptable even with a relatively low dose.

[0113] After reading the entire specification, one of ordinary skill in the art can determine the dose when forming the partially cured planarization layer 1102 to meet the requirements and desires of a particular application.

[0114] The method can include removing the superstrate from the partially cured planarization layer at block 744 in FIG. 7. FIG. 13 includes a cross-sectional view of the substrate chuck 333, the substrate 802, and the partially cured planarization layer 1102 at this point in the process.

[0115] Referring to FIGS. 3 and 4, the substrate transfer tool 310 can move the substrate 802 and the partially cured planarization layer 1102 to one of the radiation exposure stations 326 in the curing unit 301 and the heated radiation exposure station 376 in the curing unit 303. The substrate chuck 386 in the radiation exposure station 376 is coupled to the substrate 802.

[0116] The process further includes heating the partially cured planarization layer at block 762 in FIG. 7 and exposing the partially cured planarization layer to radiation to form a photo-cured planarization layer at block 764. After the partially cured planarization layer 1102 is heated to the target temperature at block 762, the partially cured planarization layer 1102 is exposed to radiation at block 764. Heating is continued to end heating before the partially cured planarization layer 1102 is exposed to radiation, or to maintain the partially cured planarization layer 1102 at the target temperature during exposure to radiation.

[0117] The target temperature for heating depends on the desired radiation exposure temperature when the partially cured planarization layer 1102 is exposed to radiation. The desired radiation exposure temperature depends on the change in thickness between the pre-cured layer 1002 and its corresponding baked planarization layer after exposure to radiation and baking, or between the partially cured planarization layer 1102 or the photo-cured planarization layer and its corresponding baked planarization layer.

[0118] A high radiation exposure temperature allows a thickness change of 0% or close to 0% between the pre-cured layer 1002 and its corresponding baked planarization layer, or between the partially cured planarization layer 1102 or the photo-cured planarization layer and its corresponding baked planarization layer. The desired radiation exposure temperature depends on the materials in the photo-curable composition. Among the materials in the photo-curable composition, the polymerizable materials have the greatest influence on the selected temperature. The photoinitiator, which can include a single photoinitiator compound or a mixture of photoinitiator compounds, can have a smaller influence on the desired radiation exposure temperature. Other materials in the photo-curable composition have no influence or only a slight influence on the desired radiation exposure temperature.

[0119] Empirical data is generated to determine the desired actinic exposure temperature. After exposure to actinic rays and baking, the thickness of the baked planarization layer may be thicker, thinner, or approximately the same as the thickness of the pre-cured layer 1002 or the partially cured planarization layer 1102. A graph may be generated from the empirical data to determine the change in thickness. Important variables for the graph can include dose information such as (1) a specific photocurable composition, (2) the post-exposure bake temperature, (3) the temperature during actinic ray exposure, and (4) the dose of actinic rays when polymerizing the pre-cured layer 1002 to form the partially cured planarization layer 1102, the dose of actinic rays when further polymerizing the partially cured planarization layer 1102 to form the photocured planarization layer, the total dose of actinic rays received by the photocurable composition for all exposures to actinic rays, or any combination thereof.

[0120] The data of the change in thickness and the four variables may be stored in a table in the memory 352. For each line in the graph, three of the four variables are kept constant and the last variable of the three or four variables is changed to determine its effect on the change in thickness. For example, for a specific photocurable composition, as the actinic exposure temperature changes, the bake temperature and the total dose are kept constant. In embodiments where the superstrate 922 remains in contact with the partially cured planarization layer 1102, empirical data or simulation data is generated when the superstrate 922 is present during heating and exposure to actinic rays. Further details regarding the empirical data can be found in the Examples section later in this specification. The following description is directed to the method of removing the superstrate 922 before heating.

[0121] The change in thickness between the pre-cured layer 1002 or the partially cured planarization layer 1102 and the corresponding bake planarization layer can be within the allowable range of the change in the target thickness. The change in the target thickness can be 0%, and the allowable range can be within the range of values that provide good planarization performance. The allowable range can be + / -2.0%, + / -1.0% or + / -0.5%. For example, the manufacturing specification may have a thickness change of 0% + / -1.0%, and thus the thickness range may be in the range of -1.0% to 1.0%.

[0122] Empirical data can be stored in a table in the memory 352 or in a database external to the system 300. The controller 350 can receive information regarding the photocurable composition, dose information, bake temperature or combinations thereof used to form the bake planarization layer and determine the desired actinic exposure temperature to be used.

[0123] After the desired actinic exposure temperature is determined, the target temperature during heating can be determined by the controller 350 or a local controller. The target temperature may be the same as or different from the desired actinic exposure temperature. For example, the substrate 802 and the partially cured planarization layer 1102 may or may not be cooled during heating and exposure of the partially cured planarization layer 1102 to actinic rays. In an embodiment, exposing the partially cured planarization layer 1102 to actinic rays can be performed while the heating means maintains the target temperature within an acceptable tolerance of the desired actinic exposure temperature (e.g., + / -2.0 °C, + / -1.0 °C, or + / -0.5 °C). In another embodiment, the heating means may be deactivated before exposure of the partially cured planarization film 1102 to actinic rays is initiated. The target temperature may be higher than the desired actinic exposure temperature such that the partially cured planarization layer 1102 is cooled to the desired actinic exposure temperature. After reading this specification, one of ordinary skill in the art can determine the target temperature for potential temperature changes between heating and exposure of the partially cured planarization layer 1102 to actinic rays.

[0124] The heating means is used to heat the substrate 802 and the partially cured planarization layer 1102 to the target temperature. Referring to FIG. 14, the heating means can include a resistive heating element 1422 within the substrate chuck 333, or a radiative heating element 1424 positioned above the substrate chuck 333. The radiative heating element 1424 can include a heat lamp, an infrared lamp, etc. Although not shown, the heating means can include an induction heater, a microwave generator for generating microwaves, a pump for assisting the flow of heated liquid through a flow path within the substrate chuck 333, or a blower for assisting convection by passing heated gas over the substrate 802 and the partially cured planarization layer 1102. The heating means can have one type of heating means (e.g., a resistive heating element, an induction heater, a radiative heating element, a microwave generator, a pump for flowing heated liquid within the substrate chuck 333, or a blower for assisting convective heating), or a combination of various heating means (a combination of two or more of the above).

[0125] The heating means provides heat so that the substrate 802 and the partially cured planarization layer 1102 reach a target temperature higher than the ambient temperature. The room in which the system 300 is located can have an ambient temperature of 20°C. In such a room, heating raises the temperature of the partially cured planarization layer 1102 by heating, such that as a result, the partially cured planarization layer 1102 reaches 21°C or higher when exposed to actinic rays. The room reaches an ambient temperature of 24°C while the system 300 is operating, and heating raises the temperature of the partially cured planarization layer 1102 so that it reaches 25°C or higher when the partially cured planarization layer 1102 is exposed to actinic rays. Depending on the ambient temperature, the target temperature can be at least 21°C, at least 25°C, at least 30°C, at least 35°C, or at least 40°C.

[0126] When the partial cured planarization layer 1102 is exposed to a sufficiently high temperature, the photocurable composition substantially polymerizes without being exposed to actinic radiation or causes excessive evaporation loss before the exposure to actinic radiation is completed. Accordingly, the target temperature should not be so high as to cause substantial polymerization or evaporation loss during heating of the photocurable composition. In an embodiment, the target temperature may be up to 120 °C. A slight amount of polymerization due to thermal curing may or may not occur at 120 °C. In another embodiment, the target temperature of heating is up to 95 °C, up to 80 °C or up to 70 °C. The target temperature of heating can be a value between any of the above minimum and maximum numbers within a range, for example, from 25 °C to 120 °C, from 25 °C to 95 °C, from 30 °C to 80 °C or from 35 °C to 70 °C.

[0127] Referring to FIG. 14, during heating, the controller 350 or the local controller receives temperature data from the temperature sensor 1432 or 1434 and can transmit a signal received by the controller 350 or the local controller such that the controller 350 or the local controller transmits a signal for heating means such as the resistive heating element 1422 or the radiative heating element 1424 to heat the substrate 802 and the partial cured planarization layer 1102 to the target temperature.

[0128] Exposure to actinic rays is performed to form the photo-curable planarization layer 1502 in FIG. 15. Referring to FIG. 3, for a specific photo-curable composition, the memory 352 can include information regarding the target wavelength or target wavelength range of the actinic rays, the target total dose or target total dose range used for the photo-curable composition, the dose used to expose the pre-cured layer 1002 to actinic rays to form the partially cured planarization layer 1102, or other data related to exposing the photo-curable composition to actinic rays. Such information is used by the controller 350 or the local controller to determine the parameters for exposing the partially cured planarization layer 1102 to actinic rays. The controller 350 can access the above-described empirical data to provide, for a specific photo-curable composition, the desired actinic ray exposure temperature, the bake temperature used during the post-exposure bake, the dose of actinic rays used to photo-cure the partially cured planarization layer 1102 to form the photo-curable planarization layer 1502, the total dose of actinic rays used for both the actinic ray exposure stations 326 and 376, or a combination thereof. The temperature at the time of heating during actinic ray exposure is herein referred to as the actual actinic ray exposure temperature. The actual actinic ray exposure temperature can be the desired actinic ray exposure temperature or in the vicinity thereof. The actual actinic ray exposure temperature is either the target temperature and tolerance range described above.

[0129] Referring to FIGS. 3, 14, and 15, the controller 350 or the local controller can receive a signal from a temperature sensor or the derivative of such a signal and determine whether the temperature is within the tolerance range (e.g., + / -5°C, + / -2°C, + / -1°C, or + / -0.5°C) of the desired actinic ray exposure temperature or within that range. If the temperature is within the tolerance range or within that range of the desired actinic ray exposure temperature, the controller 350 or the local controller can transmit a signal for the actinic ray source 1532 to be activated, as shown in FIG. 15. In an embodiment, each triangle shown for the actinic ray source 1532 is a UV lamp.

[0130] The actinic rays are emitted from an actinic ray source 1532. In an embodiment where the superstrate 922 is not removed beforehand and still exists on the partially cured planarization layer 1102 during heat-assisted actinic ray exposure, at least 70% of the actinic rays reaching the superstrate 922 pass through the superstrate 922. The actinic rays received by the partially cured planarization layer 1102 activate photoinitiators in the photocurable composition within the partially cured planarization layer 1102 to assist further polymerization of the polymerizable materials within the photocurable composition. The actinic rays can have a wavelength of at least 10 nm and less than 700 nm. The actinic rays are ultraviolet rays having a wavelength in the range of 100 nm to 400 nm, more specifically, in the range of 200 nm to 400 nm. A supplier of the photocurable composition can provide a target wavelength or a target wavelength range used to photocure the photocurable composition.

[0131] The energy from the exposure to the actinic rays forms a photocured planarization layer 1502. The photocured planarization layer 1502 has an upper surface 1512. The energy further polymerizes the polymerizable materials, forms more polymeric materials, or forms more crosslinked materials by forming more covalent bonds with adjacent molecules. The polymeric material can be a single polymer compound or a copolymer. The exposure to the actinic rays during heat-assisted actinic ray exposure substantially polymerizes the polymerizable materials within the partially cured planarization layer 1102 but does not completely polymerize them. In an embodiment, further exposure to the actinic rays does not occur. Due to thermal curing, further polymerization occurs during the post-exposure bake of the photocured planarization layer 1502. A supplier of the photocurable composition can provide a target dose or a target dose range used for the photocurable composition. Also, those skilled in the art generate empirical data for determining the dose or dose range used for a particular photocurable composition.

[0132] When the super straight 922 is present when forming the photo-curable planarization layer 1502, the super straight 922 can be removed at this point in the process. The photo-curable composition can include an internal release agent that remains in the photo-cured planarization layer 1502 after polymerization. The internal release agent can help reduce the likelihood of damaging the photo-cured planarization layer 1502 or removing some or all of the photo-cured planarization layer 1502 when removing the super straight 922.

[0133] The method can include baking the photo-curable planarization layer to form a baked planarization layer at block 782 in FIG. 7. During the baking operation, the materials within the photo-curable planarization layer 1502 can further polymerize, crosslink, or both. Also, the baking operation can help remove relatively volatile components, if present, from the photo-curable planarization layer 1502 when forming the baked planarization layer 1602 in FIG. 16. The baked planarization layer 1602 has an upper surface 1612. The baking operation may or may not cause a further change in thickness between the photo-curable planarization layer 1502 and the baked planarization layer 1602.

[0134] Referring to FIGS. 3 to 5, 15 and 16, the controller 350 or the local controller can send a signal for the substrate transfer tool 310 to remove the substrate 802 and the photo-curable planarization layer 1502 from the heat ray exposure station 376 and move the substrate 802 and the photo-curable planarization layer 1502 to the substrate pod 371. The substrate pod 371 can be moved to the baking apparatus 500 for further processes. In another embodiment, the substrate 802 and the photo-curable planarization layer 1502 can be moved to the substrate pod 571 in FIG. 5. The substrate transfer tool 510 can place the substrate 802 on the substrate chuck 586 within one of the post-exposure bake stations 576.

[0135] The heating means in the post-exposure bake station 576 is used to heat the photo-curable planarization layer 1502 (FIG. 15) to form the baked planarization layer 1602 (FIG. 16). Any of the heating means described above regarding the heating operation in the heat ray exposure station 376 can be used for the baking operation in the bake station 576. The heating means in the heat ray exposure station 376 and the baking operation in the bake station 576 may be the same or may be substantially different. FIG. 16 shows the resistive heating element 1422 in the substrate chuck 333 and the radiative heating element 1424 positioned on the substrate chuck 333. The heating means provides heat at a temperature higher than the temperature used for the heat ray exposure operation. The bake temperature can be at least 200 °C higher than the chemical ray exposure temperature. The bake temperature is at least 300 °C, at least 325 °C or at least 350 °C. The bake temperature should not be so high as to cause significant decomposition or other adverse effects on the baked planarization layer 1602. The bake temperature can be up to 500 °C, up to 450 °C or up to 400 °C. The bake temperature can be a value between any of the above minimum and maximum numbers, for example, in the range of 300 °C to 500 °C, 300 °C to 450 °C or 300 °C to 400 °C. In a particular embodiment, the bake temperature is in the range of 350 °C to 400 °C. All of the bake temperature, the soak time at the bake temperature and the monomers in the photo-curable composition affect the planarization performance of the baked planarization layer 1602. The monomers in the photo-curable composition are selected based on at least all of the bake temperature, the soak time at the bake temperature and the desired planarization performance of the baked planarization layer 1602. Also, the performance of the baked planarization layer 1602 in subsequent process steps depends on the bake temperature, the soak time at the bake temperature and the monomers in the photo-curable composition.

[0136] The soak time is the time that the substrate 802 and the polymer layer thereon are at the bake temperature. The soak time needs to be sufficient to achieve the required or desired amount of further polymerization or crosslinking, reduce the amount of volatile components in the polymer layer to the desired amount, or both. The soak time is at least 0.25 minutes, at least 1 minute, or at least 3 minutes. After a sufficiently long time, further exposure to the bake temperature may not sufficiently improve the polymer layer (such that a sufficient amount of polymerization or crosslinking has occurred and the remaining amount of volatile components is low enough not to cause problems during subsequent processes, etc.), or may begin to cause adverse effects such as roughening of the upper surface 1612 of the bake flattening layer 1602, possible delamination of the bake flattening layer 1602 from the substrate 802, etc. The soak time may be at most 30 minutes, at most 20 minutes, or at most 15 minutes. The soak time is a value between any of the above minimum and maximum numbers, for example, in the range from 0.25 minutes to 30 minutes, from 1 minute to 20 minutes, or from 3 minutes to 15 minutes.

[0137] The bake operation can be performed using a gas. The gas can include materials that are relatively inert with respect to the photo-curable flattening layer 1502 and the bake flattening layer 1602. The materials can include N 2 , CO 2 , noble gases (such as Ar, He, etc.), or mixtures thereof. The gas may not contain oxidizing substances, for example, O 2 , O 3 , N 2 O, etc., or may contain oxidizing substances of 2 mol% or less, or 0.5 mol% or less.

[0138] As shown, the post-exposure bake station 576 is configured to process a single substrate at a time. In another embodiment, the post-exposure bake station 576 can be configured to process multiple substrates during the same bake operation. The post-exposure bake station 576 can include a cassette or another suitable substrate container, or can receive a cassette or another suitable substrate container, and the cassette or other suitable substrate container can hold multiple substrates.

[0139] The memory 552, the database, or another memory external to the apparatus 500 can contain information regarding the composition of the polymer precursor used to form the photo-curable planarization layer, the desired bake temperature, or the desired soak time for forming the bake planarization layer 1602. Referring to FIG. 5, the controller 550 or the local controller can send a signal for the post-exposure bake station 576 to flow an inert gas within the post-exposure bake station 576 and control the heating means to maintain the substrate 802 and the photo-curable planarization layer 1502 within an acceptable range or within the acceptable range of the desired bake temperature for the soak time. Referring to FIG. 16, during heating, the controller 550 or the local controller receives temperature data from the temperature sensor 1632 or 1634, and the controller 550 or the local controller sends a signal for the heating means such as the resistive heating element 1622 or the radiative heating element 1624 to heat the substrate 802 and the photo-curable planarization layer 1102 to the bake temperature, or to send a signal received by the controller 550 or the local controller to maintain the temperature within the post-exposure bake station 576 at the bake temperature. The acceptable range is + / -10 °C, + / -5 °C, or + / -2 °C of the desired bake temperature. After the soak time, the controller 550 or the local controller can send a signal to the substrate transfer tool 510 to remove the substrate 802 and the bake planarization layer 1602 from the post-exposure bake station 576. The substrate 802 and the bake planarization layer 1602 are moved by the substrate transfer tool 510 to a cooling plate to lower the temperature of the substrate 802 and the bake planarization layer 1602 before the substrate 802 and the bake planarization layer 1602 are returned to the substrate pod 571. After the cooling is complete, the controller 550 or the local controller can send a signal to move the substrate 802 and the bake planarization layer 1602 to the substrate pod 571.

[0140] After reading this specification, those skilled in the art will understand that many system configurations and process options are available without departing from the concepts described herein. Those skilled in the art will be able to determine the specific methods to use to meet the needs or desires of a particular system configuration and a particular application.

[0141] The process described above can be used when forming a planarization layer from a photocurable composition. The process described above can be integrated as part of a manufacturing method for manufacturing an article. The article can be an electric circuit element, an optical element, a microelectromechanical system (MEMS), a recording element, a sensor, a mold, an integrated circuit, etc. The integrated circuit can be a solid-state device (DRAM (dynamic random access memory)), SRAM (static random access memory), flash memory, MRAM (magnetoresistive random access memory), a microprocessor, a microcontroller, a graphics processing unit, a digital signal processor, a field programmable gate array (FPGA).

[0142] The method can further include subjecting the substrate 802 and the baked planarization layer 1602 to other processes for device (article) manufacturing, including, for example, curing, oxidation, layer formation, deposition, doping, planarization, lithography, etching, removal of formable material, dicing, bonding, and packaging. The substrate may be processed to manufacture a plurality of articles (devices), for example, the substrate may be a semiconductor wafer.

[0143] Example

[0144] The following examples are provided to demonstrate that the change in the thickness of the layer formed from the photocurable composition is affected by the temperature of the photocurable composition during exposure to actinic radiation. The examples are for the purpose of assisting in the understanding of the concepts described herein and are not intended to limit the scope of the invention as defined in the appended claims. In the examples, the value of the change in thickness is rounded to the nearest tenth of a percent.

[0145] Six sample sets are prepared and include a substrate having a height difference between protrusions and recesses of 100 nm + / - 5 nm. One, both, or neither of a surfactant and a solvent may be included. The weight % values are based on the total weight of the photocurable composition, and the sum of the weight % values is 100 weight %. Exposure to actinic radiation is performed at a surface output density of 35 to 50 mW / cm 2 and the photocurable planarization layer formed from the photocurable planarization layer is baked at 350 to 400 °C for a soak time of 1.5 to 3.0 minutes. The ranges of values are listed above, but all substrates were processed with the same photocurable composition, the same surface output density, bake temperature, and soak time set values. The actual surface output density, bake temperature, and soak time vary slightly due to the reproducibility limitations of the process equipment.

[0146] Table 4 below includes a list of the sample sets and actinic radiation exposure conditions. The superstrate contacted the photocurable composition during Step 1 and was removed prior to Step 2. Referring to FIGS. 3 and 4, Step 1 is performed at the actinic radiation exposure station 326 within the unit 301, and Step 2 is performed at the actinic radiation exposure station 376 within the unit 303. The room temperature is 23 °C.

[0147] [Table 4]

[0148] For the sample sets at 23 °C, 30 °C, 40 °C, and 50 °C, the dose in Step 2 was 1.5 J / cm from the total dose in Step 1. 2is subtracted. Therefore, for a total dose of 5 J / cm 2 the dose during Step 2 is 3.5 J / cm 2 and for a total dose of 10 J / cm 2 the dose during Step 2 is 8.5 J / cm 2 and for a total dose of 15 J / cm 2 the dose during Step 2 is 13.5 J / cm 2 and for a total dose of 20 J / cm 2 the dose during Step 2 is 18.5 J / cm 2 .

[0149] FIG. 18 includes plots of samples for different total doses. For all sample sets, the layer shrinks by the process. The shrinkage in FIG. 18 represents a negative change in thickness. A shrinkage value close to 0% is desirable.

[0150] The 1-step 50° C. sample set exhibits the best performance with respect to shrinkage. The shrinkage is 1.8% at a total dose of 20 J / cm 2 and 2.1% at a total dose of 15 J / cm 2 . The 1-step 23° C. (room temperature) sample set did not have performance similar to the 1-step 50° C. sample set. The shrinkage of the 1-step 23° C. samples reaches 2.7% at a total dose of 20 J / cm 2 .

[0151] Both 1-step 50° C. and 1-step 23° C. may take 5 minutes to reach a total dose of 20 J / cm 2 . The 1-step 50° C. sample set and the 1-step 23° C. sample set take too long to photocure at the actinic exposure station 326, adversely affecting the throughput of the unit 301. Other sample sets are photocured in 40 seconds or less at the actinic exposure station 326. The 2-step process requires substantially less time at the actinic exposure station 326 and allows for higher throughput via the system 300.

[0152] The sample at 50 °C shows a shrinkage of 2.0% at a total dose of 20 J / cm 2 . Thus, the sample set at 50 °C can achieve approximately the same shrinkage as the sample set at 1-step 50 °C. At total doses of 5 J / cm 2 and 10 J / cm 2 , the shrinkage of the sample set at 50 °C and the sample set at 1-step 23 °C is approximately the same. The sample at 40 °C shows a shrinkage of 2.5% at a total dose of 20 J / cm 2 . The sample at 30 °C shows a shrinkage of 3.1% at a total dose of 20 J / cm 2 . The substrate and the partially cured planarization layer are heated for the actinic exposure in step 2 for the sample sets at 50 °C, 40 °C, and 30 °C.

[0153] In the actinic exposure in step 2, the sample set at 23 °C is at room temperature and not heated. The sample at 23 °C has a shrinkage of 4.3% at a total dose of 20 J / cm 2 . The two-step process where step 2 is performed at room temperature is not acceptable for excessive shrinkage. For example, the upper limit of shrinkage is 4% for a substrate having a height difference of 200 nm, and the dimensional change along the bake planarization layer (D 48 in Equation 2) is limited to 8 nm.

[0154] The samples are not intended to limit the scope of the invention as defined by the appended claims. The heat-assisted actinic exposure can be performed at a temperature higher than 50 °C, such as 60 °C, 80 °C, 95 °C, or another temperature higher than room temperature.

[0155] The embodiments described herein, when forming a planarization layer using an IAP process, can achieve a higher manufacturing volume while maintaining a low thickness variation. In an embodiment, a pre-cured layer of a photocurable composition is exposed to actinic radiation at room temperature to form a partially cured planarization layer, and the partially cured planarization layer can be exposed to actinic radiation at another temperature to form a photocured planarization layer. The photocured planarization layer can be baked to form a baked planarization layer. High throughput can be achieved by exposing to actinic radiation at room temperature for a relatively short time within a station for actinic radiation exposure, and the relatively long-time heat actinic radiation exposure within a heat actinic radiation exposure station helps to reduce the amount of thickness variation such as shrinkage between the pre-cured layer and its corresponding baked planarization layer.

[0156] In general descriptions or examples, not all of the activities described above are required, some of a particular activity may not be required, and in addition to those described, one or more further activities may be performed. It should also be noted that the order in which activities are listed is not necessarily the order in which they are performed.

[0157] Benefits, other advantages, and solutions to problems are described above with respect to specific embodiments. However, a benefit, an advantage, a solution to a problem, and any feature that causes or makes more prominent any benefit, advantage, or solution should not be construed as a critical, necessary, or essential feature of any of the claims.

[0158] The specification and examples of the embodiments described in this specification are intended to provide a general understanding of the structures of various embodiments. The specification and examples do not comprehensively and inclusively describe all the elements and features of the devices and systems using the structures or methods described in this specification. Separate embodiments can also be provided in combination in a single embodiment, but for the sake of brevity, the various features described in the context of a single embodiment can be provided separately or in any sub-combination. Further, references to values described in ranges include each and every value within that range. Many other embodiments will become apparent to those skilled in the art after reading this specification. Other embodiments are used and derived from the present disclosure such that structural substitutions, logical substitutions or other changes are made without departing from the scope of the present disclosure. Accordingly, the present disclosure should be construed as illustrative and not restrictive.

Claims

1. 1. A method comprising: exposing the photocurable composition to a first actinic radiation at a first temperature; exposing the photocurable composition to second actinic radiation at a second temperature to form a cured planarizing layer; Equipped with The second temperature is higher than an ambient temperature and different from the first temperature. A method comprising:

2. further comprising dispensing the photocurable composition onto a substrate; exposing the photocurable composition to the first actinic radiation is performed such that the photocurable composition is disposed between the substrate and a superstrate.

2. The method of claim 1 .

3. 3. The method of claim 2, further comprising removing the superstrate after exposing the photohardenable composition to the first actinic radiation and before exposing the photohardenable composition to the second actinic radiation.

4. 2. The method of claim 1 , wherein exposing the photohardenable composition to the first actinic radiation and exposing the photohardenable composition to the second actinic radiation are performed such that the second temperature is greater than the first temperature.

5. baking the cured planarization layer to form a baked planarization layer; exposing the photocurable composition to the first actinic radiation is at a first radiation dose; exposing the photocurable composition to the second actinic radiation is performed at a second radiation dose; the thermal shrinkage of the baked planarization layer is less than the thermal shrinkage of a different baked planarization layer formed from the photocurable composition by exposing the photocurable composition to a single radiation dose at the ambient temperature, followed by baking at a bake temperature and soak time; the single radiation dose being the sum of the first radiation dose and the second radiation dose.

2. The method of claim 1 .

6. 6. The method of claim 5, wherein baking the hardened planarization layer is performed at a bake temperature ranging from 300° C. to 500° C. and a soak time ranging from 1 minute to 60 minutes.

7. The method of claim 1 , wherein the photocurable composition comprises a polymerizable material that includes an aryl group.

8. The method of claim 7 , wherein the polymerizable material comprises vinylbenzene.

9. 10. The method of claim 1, wherein exposing the photocurable composition to the second actinic radiation occurs in an environment containing up to 2 mole percent oxygen-containing gas.

10. exposing the photocurable composition to the first actinic radiation is at a first radiation dose; exposing the photocurable composition to the second actinic radiation is performed at a second radiation dose; the first radiation dose is at most 30% of the sum of the first radiation dose and the second radiation dose; 2. The method of claim 1 .

11. 1. A method comprising: exposing a photocurable composition to first actinic radiation, the photocurable composition being located between a substrate and a superstrate; removing the superstrate from the photocurable composition; exposing the photocurable composition to a second actinic radiation to form a cured planarizing layer; and Equipped with removing the superstrate occurs after exposing the photohardenable composition to the first actinic radiation and before exposing the photohardenable composition to the second actinic radiation. A method comprising:

12. The method of claim 11 , further comprising baking the hardened planarizing layer to form a baked planarizing layer.

13. 13. The method of claim 12, wherein baking the hardened planarization layer is performed at a bake temperature of at least 300°C and a soak time of at least 1 minute.

14. 14. The method of claim 13, wherein baking the hardened planarization layer is performed at a bake temperature of up to 500° C. and a soak time of up to 60 minutes.

15. exposing the photocurable composition to the first actinic radiation is at a first radiation dose; exposing the photocurable composition to the second actinic radiation is performed at a second radiation dose; the thermal shrinkage of the baked planarization layer is less than the thermal shrinkage of a different baked planarization layer formed from the photocurable composition by exposing the photocurable composition to a single radiation dose at ambient temperature and subsequently baking at the bake temperature and soak time; the single radiation dose being the sum of the first radiation dose and the second radiation dose.

14. The method of claim 13.

16. exposing the photocurable composition to the first actinic radiation occurs at a first temperature; exposing the photocurable composition to the second actinic radiation occurs at a second temperature; The second temperature is higher than the first temperature.

12. The method of claim 11 .

17. 1. A system comprising: a first actinic radiation exposure station including a first actinic radiation source configured to emit first actinic radiation at a first wavelength less than 700 nm to expose a photocurable composition disposed between the substrate and the superstrate; a superstrate removal tool for removing the superstrate from the photocurable composition; a second actinic radiation exposure station located remotely relative to the first actinic radiation exposure station; Preparation, The second actinic radiation exposure station includes: a second actinic radiation source configured to emit second actinic radiation at a second wavelength less than 700 nm to expose the photocurable composition to form a cured planarizing layer; a heating means for heating the photocurable composition and the substrate to an actinic radiation exposure temperature; activating the superstrate removal tool to remove the superstrate after a first actinic radiation exposure in the first actinic radiation exposure station and before a second actinic radiation exposure in the second actinic radiation exposure station; controlling the heating means to heat the photocurable composition and the substrate to the actinic radiation exposure temperature above ambient temperature; A controller configured as follows: Including, A system characterized by:

18. 20. The system of claim 17, further comprising a dispensing head configured to dispense the photocurable composition onto the substrate.

19. a first unit including the dispense head, the superstrate removal tool, and the first actinic radiation exposure station; a second unit including the second actinic radiation exposure station; the second unit is distinct from the first unit and spaced apart from the first unit; 20. The system of claim 18.

20. a bake station configured to heat the hardened planarization layer to form a baked planarization layer; the bake station is configured to heat the substrate and the hardened planarization layer to a bake temperature in the range of 300° C. to 400° C.

20. The system of claim 17 .

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