System including array including heat source and actinic radiation source

Abstract

To allow more flexibility regarding heating and exposure operations and allow a system to occupy less area.SOLUTION: A system can include an array of at least one heat source adapted to heat a stack including a superstrate, a substrate, and a polymerizable composition between the superstrate and the substrate and at least one actinic radiation source adapted to at least photocure the polymerizable composition to form a photocured planarization layer. Implementations of the system does not require separate stations for heating a pre-cured layer of a polymerizable composition and exposing the pre-cured layer. The array of actinic radiation sources and heat sources allow greater flexibility with respect to timing for heating and exposing to actinic radiation the pre-cured layer. The system can be used in a method that forms a photocurable planarization layer from a pre-cured layer of a polymerizable composition.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to systems that include arrays that include thermal and actinic radiation sources, and methods of using same. [Background technology]

[0002] Inkjet-based adaptive planarization (IAP) is used in microelectronics manufacturing. As the dimensions of microelectronic components continue to shrink, processes involving IAP become more challenging. IAP can be performed such that the polymerizable composition is at a temperature above room temperature while it is exposed to actinic radiation. There is a need for a system designed to allow the polymerizable composition to be heated during exposure while maintaining acceptable throughput when forming a planarization layer. Summary of the Invention [Means for solving the problem]

[0003] In one aspect, a system can include an array of at least one heat source configured to emit heat at a peak heating wavelength and heat a stack including a superstrate, a substrate, and a polymerizable composition between the superstrate and the substrate, and at least one actinic radiation source configured to emit actinic radiation at a peak actinic wavelength and photocure at least the polymerizable composition to form a photocured planarizing layer, wherein the peak heating wavelength can be different from the peak actinic radiation wavelength.

[0004] In embodiments, the peak heating wavelength is greater than the peak actinic wavelength.

[0005] In another embodiment, the at least one heat source is configured to emit heat at the peak heating wavelength in the range of 400 nm to 2500 nm.

[0006] In certain embodiments, the peak heating wavelength ranges from 400 nm to 1100 nm.

[0007] In another particular embodiment, the peak heating wavelength ranges from 960 nm to 2500 nm.

[0008] In further specific embodiments, the at least one actinic radiation source is configured to emit actinic radiation at the peak actinic wavelength of at least 10 nm and less than 400 nm.

[0009] In another embodiment, the at least one heat source comprises a plurality of point heat sources.

[0010] In yet another embodiment, the at least one heat source includes at least one resistive heating element.

[0011] In yet another embodiment, the system further includes a bake station configured to bake the substrate and the photo-cured planarization layer, and a controller configured to receive bake station information and send a signal to the at least one heat source based on the bake station information.

[0012] In a further embodiment, the system described in claim 1 further includes a stage configured to move the substrate, and a first insulating member disposed between the stage and the at least one heat source.

[0013] In certain embodiments, the system further includes a cooling means configured to reduce the amount of heat from the at least one heat source reaching the stage, the cooling means being disposed between the stage and the first insulating member.

[0014] In a more particular embodiment, the system further includes a second insulating member, and the cooling means is disposed between the first insulating member and the second insulating member.

[0015] In another embodiment, the system further includes a stage configured to move the substrate, and a substrate chuck configured to support the substrate and disposed between the stage and the at least one heat source.

[0016] In certain embodiments, the substrate chuck includes a cooling means configured to reduce the amount of heat from the at least one heat source that reaches the stage.

[0017] In a more specific embodiment, the substrate chuck further includes a thermal insulator for reducing the amount of heat from the at least one heat source that reaches the stage.

[0018] In another aspect, a method can include heating a stack to a target temperature with at least one heat source, the stack including a substrate, a superstrate, and a polymerizable composition disposed between the superstrate and the substrate. The at least one heat source can emit heat at a peak heating wavelength. An array can include the at least one heat source and at least one actinic radiation source. The method can further include curing the polymerizable composition to form a photocured planarizing layer, the curing occurring by exposing the stack to radiation emitted by the at least one actinic radiation source, the at least one actinic radiation source emitting actinic radiation at a peak actinic radiation wavelength. The peak heating wavelength can be different from the peak actinic radiation wavelength.

[0019] In an embodiment, during warming, the stack is placed on a substrate chuck, the substrate chuck is coupled to a stage, and the temperature of the stage is below a threshold when the stack is at the target temperature.

[0020] In certain embodiments, the method further comprises activating a cooling means disposed between the stack and the stage during heating, curing, or both.

[0021] In another particular embodiment, the method further comprises moving the stack while the polymerizable composition is cured and at a temperature above ambient temperature.

[0022] In another embodiment, when the polymerizable composition is below the target temperature, the dose of actinic radiation emitted from the at least one source of actinic radiation is below a threshold value.

[0023] In a further embodiment, the method further comprises baking the substrate and the photocured planarization layer at a baking temperature to form a baked planarization layer, wherein during curing, the polymerizable composition is at a desired radiation exposure temperature ±3°C, and the desired radiation exposure temperature is selected based at least in part on the baking temperature. [Brief explanation of the drawings]

[0024] Embodiments are illustrated by way of example and not limitation in the accompanying figures. [Figure 1] FIG. 1 includes a conceptual diagram of a portion of a system that can be used to form a photocured planarizing layer from a polymerizable composition. [Figure 2] FIG. 2 includes a schematic diagram of another portion of the system of FIG. 1, including a post-exposure bake station. [Figure 3] FIG. 3 includes a cross-sectional view of a portion of the station including the radiation head assembly, substrate chuck and positioning stage. [Figure 4] FIG. 4 includes a bottom-up view of an array of thermal and actinic radiation sources in an embodiment. [Figure 5] FIG. 5 includes a bottom-up view of an enlarged portion of the array of FIG. [Figure 6] FIG. 6 includes a bottom-up view of an array in another embodiment. [Figure 7] FIG. 7 includes a bottom-up view of an array in yet another embodiment. [Figure 8]FIG. 8 includes a bottom-up view of an array in yet another embodiment. [Figure 9] FIG. 9 includes a bottom-up view of an array in a further embodiment. [Figure 10] FIG. 10 includes a bottom-up view of an array in another embodiment. [Figure 11] FIG. 11 includes a process flow diagram for forming a baked planarization layer from a polymerizable composition. [Figure 12] FIG. 12 includes an illustration of a cross-sectional view of the positioning stage, substrate chuck, substrate, and dispense head when dispensing droplets of polymerizable composition onto the substrate. [Figure 13] FIG. 13 includes an illustration of a cross-sectional view of the positioning stage, substrate chuck, and substrate as the superstrate and substrate / droplet combination are moved closer together. [Figure 14] FIG. 14 includes an illustration of a cross-sectional view of the positioning stage, substrate chuck, substrate, and superstrate of FIG. 12 after forming a pre-cured layer of polymerizable composition. [Figure 15] FIG. 15 includes an illustration of a cross-sectional view of the positioning stage, substrate chuck, substrate, superstrate, and pre-cured layer of FIG. 13 during heating of the pre-cured layer. [Figure 16] FIG. 16 includes an illustration of a cross-sectional view of the positioning stage, substrate chuck, substrate, superstrate, and pre-cured layer of FIG. 13 as the pre-cured layer is exposed to heat and actinic radiation. [Figure 17] FIG. 17 includes an illustration of a cross-sectional view of the positioning stage, substrate chuck, substrate, superstrate, and pre-cured layer of FIG. 13 during exposure of the pre-cured layer to actinic radiation. [Figure 18] FIG. 18 includes a timing diagram illustrating when the pre-cured layer is heated and exposed to actinic radiation in an embodiment. [Figure 19]FIG. 19 includes a timing diagram illustrating when a pre-cured layer is heated and exposed to actinic radiation in another embodiment. [Figure 20] FIG. 20 includes a timing diagram illustrating when the pre-cured layer is heated and exposed to actinic radiation in yet another embodiment. [Figure 21] FIG. 21 includes a timing diagram illustrating when a pre-cured layer is heated and exposed to actinic radiation in yet another embodiment. [Figure 22] FIG. 22 includes a timing diagram illustrating when the pre-cured layer is heated and exposed to actinic radiation in a further embodiment. [Figure 23] FIG. 23 includes a timing diagram illustrating when a pre-cured layer is heated and exposed to actinic radiation in another embodiment. [Figure 24] FIG. 24 includes a timing diagram illustrating when the pre-cured layer is heated and exposed to actinic radiation in yet another embodiment. [Figure 25] FIG. 25 includes a timing diagram illustrating when the pre-cured layer is heated and exposed to actinic radiation in yet another embodiment. [Figure 26] FIG. 26 includes a timing diagram illustrating when the pre-cured layer is heated and exposed to actinic radiation in a further embodiment. [Figure 27] FIG. 27 includes an illustration of a cross-sectional view of the positioning stage, substrate chuck, substrate, superstrate, and pre-cured layer of FIG. 13 after forming a photo-cured planarizing layer. [Figure 28] 28 includes an illustration of a cross-sectional view of the substrate chuck and substrate of FIG. 27 after baking the photocured planarizing layer to form a baked planarizing layer. Those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to facilitate an understanding of embodiments of the inventive concepts. DETAILED DESCRIPTION OF THE INVENTION

[0025] The following description in combination with the drawings is provided to aid in understanding the teachings disclosed herein. The following discussion focuses on specific embodiments of the teachings. This focus is provided to help explain the teachings and should not be construed as a limitation on the scope or applicability of the teachings.

[0026] 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 are 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.

[0027] The system can include an array of at least one heat source and at least one actinic radiation source. The heat source can be configured to emit heat at a peak heating wavelength to heat a stack including the superstrate, the substrate, and the polymerizable composition between the superstrate and the substrate, and the actinic radiation source can be configured to emit actinic radiation at a peak actinic wavelength to photocure at least the polymerizable composition to form a photocured planarizing layer. The peak heating radiation wavelength can be different from the peak actinic radiation wavelength.

[0028] The system can provide increased flexibility regarding heating and exposure operations and can reduce the system footprint. Separate stations are not required for heating and exposing the pre-cured layer of polymerizable compound. The array of actinic radiation and heat sources allows for greater flexibility regarding the timing for heating and exposing the pre-cured layer to actinic radiation. The heat source can be activated before, simultaneously with, or after activating the actinic radiation source. The actinic radiation source can be deactivated before, simultaneously with, or after deactivating the heat source. After initial heating, a heat pulse is used to help maintain the temperature of the pre-cured layer within a narrower range compared to a heat pulse that is not used. The actinic radiation source, the heat source, or the actinic radiation and the heat source may be configured to operate at two or more power levels. In this manner, the amount of actinic radiation, heat, or both may be varied as a function of time.

[0029] The system 100 shown in Figures 1 and 2 can be used for the method. The system is suitable for the IAP process. After reading this specification, those skilled in the art can determine the number of devices and their corresponding operations when designing a system.

[0030] 1 and 2 include a conceptual diagram of a system 100 that can be used to form a baked planarizing layer from a polymerizable composition. The system 100 can include a curing apparatus 101 and a post-exposure bake apparatus 201 that can be used to bake the photo-cured planarizing layer into a baked planarizing layer. The polymerizable composition is mostly cured before baking; some curing occurs during the post-exposure bake operation.

[0031] The curing apparatus 101 includes a substrate transfer tool 110, a substrate pod 121, a dispensing station 123, a planarizing head station 125, a heating radiation exposure station 126, a controller 150, and a memory 152. The dispensing station 123 can include a substrate chuck 133 that can be coupled to a positioning stage (shown in subsequent figures) that allows the substrate chuck 133 to be moved during the dispensing operation. Another positioning stage (shown in subsequent figures) can be used to move the substrate chuck 136 between stations 125 and 126. The bake apparatus 201 in FIG. 2 can include a substrate transfer tool 210, a bake unit 270, a controller 250, and a memory 252. The bake unit 270 can include a substrate pod 271 and at least one bake station 276, each of which can include a substrate chuck 286.

[0032] Many of the above-mentioned components are described below with respect to the functions they perform. Details regarding the operation of the components, particularly stations 123, 125, 126 and 276, are described in detail later in this specification with respect to methods of using the system.

[0033] The substrate transfer tool 110 can be configured to transfer a substrate to or from the substrate pod 121, the dispense station 123, the planarization head station 125, and the heating radiation exposure station 126. The substrate transfer tool 210 can be configured to transfer at least one substrate to or from the substrate pod 271 and the bake station 276. The substrate transfer tools 110 and 210 can be or include at least one component of an Equipment Front End Module (EFEM). The EFEM components can include at least one of a robot arm, a robot hand configured to hold a substrate, a sensor, a motor for moving the robot arm, and another motor for moving the robot arm. The robot arm can be configured to move a substrate, with or without a layer, between stations, for example, to or from the substrate pod 121, the dispense station 123, the planarization head station 125, and the heating radiation exposure station 126. The substrate transfer tool 210 in FIG. 2 may be the same as or different from the substrate transfer tool 110 in FIG.

[0034] 1 and 2, substrate pods 121 and 271 can hold multiple substrates. An example of a substrate pod is a Front Opening Unified Pod (FOUP), which is defined by industry standards (e.g., SEMI E47.1-1106, 2012) as a pod for storing and transporting substrates. The systems described herein include coupling plates, interface holes, and load ports for receiving and transferring substrates between one to four substrate pods. Substrates can be removed from substrate pod 121, processed in a station of system 100, such as stations 123, 125, 126, or a combination thereof, and moved to substrate pod 121 or another substrate pod once processing in the portion of system 100 shown in FIG. 1 is complete. Substrates can be removed from substrate pod 271, processed in at least one bake station 276, and returned to substrate pod 271 or another substrate pod once baking is complete.

[0035] The dispense station 123 can be configured to receive a substrate and dispense a polymerizable composition onto the substrate. When the substrate is on the substrate chuck 133, a dispense head 146 can be used to dispense the polymerizable composition onto the substrate. The dispense head 146 can include at least one nozzle for dispensing the polymerizable composition. A dashed line in the dispense head 146 is used to indicate that the polymerizable composition is dispensed along the bottom surface of the dispense head 146. A positioning stage (not shown in FIG. 1 ) can be coupled to the substrate chuck 133, and the positioning stage, the dispense head 146, or both can be configured to move when dispensing the polymerizable composition. Further details regarding the polymerizable composition and methods for dispensing and processing the polymerizable composition are described later in this specification. The substrate transfer tool 110 can transfer the substrate and the polymerizable composition on the substrate from the dispense station 123 to the substrate chuck 136 after a different positioning stage (not shown in FIG. 1 ) coupled to the substrate chuck 136 moves to the planarization head station 125.

[0036] The planarizing head station 125 can include a planarizing head 135 configured to position a superstrate in contact with the polymerizable composition. The superstrate can be positioned to contact the droplets of the polymerizable composition, causing the droplets to coalesce and form a pre-cured layer of the polymerizable composition. In embodiments, the planarizing head 135 can be configured to remove the superstrate after the polymerizable composition has sufficiently cured. FIG. 1 illustrates the planarizing head station 125. In practice, two or more planarizing head stations are used. In a non-limiting embodiment, the ratio of planarizing head stations to heating radiation exposure stations is 1:1. In other embodiments, the ratio can be lower (relatively fewer planarizing head stations) or higher (relatively more planarizing head stations).

[0037] A positioning stage coupled to substrate chuck 136 can transport the substrate and the pre-cured layer of polymerizable composition on the substrate from planarization head station 125 to heating radiation exposure station 126. In an alternative embodiment, the positioning stage can be shared by stations 123, 125, and 126, rather than having two different positioning stages.

[0038] The heating radiation exposure station 126 can be configured to photocure the polymerizable composition. A pre-cured layer of the polymerizable composition can be exposed to actinic radiation when the pre-cured layer is at a temperature higher than ambient temperature. Ambient temperature is the temperature of the room in which the station is located within the apparatus. Thus, ambient temperature can be room temperature. For example, ambient temperature can be in the range of 20°C to 25°C. The actinic radiation can polymerize the polymerizable material within the polymerizable composition to form a photo-cured planarizing layer. The photo-cured planarizing layer can be further cured in an optional curing station, with or without a superstrate, before being baked.

[0039] The positioning stage shared by stations 125 and 126 can move the substrate chuck, substrate and photocured planarization layer from heating radiation exposure station 126 to planarization head station 125 where the superstrate can be removed after the radiation exposure operation in heating radiation exposure station 126 is completed.

[0040] The heating radiation exposure station 126 can be configured to perform two operations: heating the pre-cured layer and exposing the pre-cured layer to actinic radiation to form a photocured planarizing layer. Further details regarding the heat source, the actinic radiation source, heating the pre-cured layer, and exposing it to actinic radiation are provided later in this specification.

[0041] FIG. 1 illustrates a heating radiation exposure station 126. In practice, two or more heating radiation exposure stations are used. When multiple heating radiation exposure stations 126 are used, the arrangement of the heating radiation exposure stations 126 may be planar, with the heating radiation exposure stations 126 existing along a single plane, stacked, or a combination of heating radiation exposure stations 126 existing along a single plane and other combinations of stacked heating radiation exposure stations 126. Stacking the heating radiation exposure stations 126 can help reduce the area occupied by the stations 126. The number of heating radiation exposure stations 126 in a stack may be two or more. Due to height constraints in the room in which the stations 126 are located and the height of each heating radiation exposure station, the number of heating radiation exposure stations 126 in a stack is limited to nine stations, seven stations, or five stations. The number of stacks can be one or more. The number of stacks is limited by the available floor space in the room in which the curing unit is located. The number of stacks in the heating radiation exposure station 126 may be limited to nine stacks, seven stacks, or five stacks.

[0042] 2, the post-exposure bake unit 270 can include a substrate pod 271 and a post-exposure bake station 276 including a substrate chuck 286. The post-exposure bake station 276 can further polymerize or crosslink the polymerizable composition in the photocured planarization layer due to thermal curing, cause different reactions of components in the polymerizable composition, drive off volatile components in the polymerizable composition, etc.

[0043] The post-exposure bake station 276 can include a heating means. The heating means for the post-exposure bake station 276 can be activated to bake the photo-cured planarizing layer. Further details regarding the heating means for the post-exposure bake station 276 are provided later in this specification. Direct temperature measurements of the photo-cured planarizing layer can be difficult to obtain. Thus, the temperature of the photo-cured planarizing layer can correspond to different temperatures within the heating radiation exposure station 126. The temperature of the photo-cured planarizing layer can be correlated to the temperature of its corresponding substrate chuck 286 or the substrate or superstrate on such substrate chuck 286. Users of the system 100 can use the temperature of the substrate chuck 286, substrate, or superstrate to control operation, since direct temperature measurements of the photo-cured planarizing layer may be impractical. The temperature used for the post-exposure bake can be at least 300°C. The highest process temperature associated with the post-exposure bake station 276 can be 500°C.

[0044] The above-described operations performed by any particular station may be moved or combined with other stations. For example, dispensing of the polymerizable composition and placement and removal of the superstrate may occur within the same station. For example, placement and removal of the superstrate may occur using a planarizing head if present within either of stations 123 and 126. Thus, planarizing head station 125 is not required in all embodiments.

[0045] Each of the substrate chucks 133, 136, and 286 can be a vacuum chuck, a pin-type chuck, a groove-type chuck, an electrostatic chuck, an electromagnetic chuck, etc. The substrate chucks 133, 136, and 286 can be the same type, such as a vacuum chuck, or different types. For example, one of the substrate chucks can be a vacuum chuck and another of the substrate chucks can be an electrostatic chuck or an electromagnetic chuck. Each of the substrate chucks 133, 136, and 286 may or may not have heating elements, cooling elements, or both used to heat or cool the substrate and layers, if any, and the superstrate overlying the substrate. Further details of substrate chuck design are provided later in this specification.

[0046] Controller 150 is coupled to memory 152 and can control components within curing apparatus 101, and controller 250 is coupled to memory 252 and can control components within bake apparatus 201. Controller 150 and memory 152 are described in detail below. The description of controller 150 is applicable to controller 250, and the description of memory 152 is applicable to memory 252, except where explicitly noted when specifying particular details of system 100.

[0047] Any combination of controllers 150 and 250 can communicate with each other if necessary or desired. For example, one or both of controllers 150 and 250 can be used to verify that a particular lot of substrates with a photo-cured planarizing layer in substrate pod 271 have completed processing in curing apparatus 101 before the substrates and photo-cured planarizing layer are baked in post-exposure bake station 276 of bake unit 270.

[0048] Controllers 150 and 250 may optionally operate using a computer-readable program stored in memory 152 or 252. Either or both of controllers 150 and 250 may 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), or the like. Either or both of controllers 150 and 250 may further include internal memory, such as a set of registers, cache memory, flash memory, or the like. Controllers 150 and 250 may be within system 100. In another system embodiment (not shown), one or both of controllers 150 and 250 may be at least part of a computer external to system 100, such computer being bidirectionally coupled to system 100.

[0049] Any or all of memories 152 and 252 may include non-transitory computer-readable media containing instructions for performing operations related to or during operations. Any or both of memories 152 and 252 may include a set of registers, cache memory, flash memory, a hard drive, etc. Any or both of memories 152 and 252 may further include data tables that can be accessed by either or both of controllers 150 and 250 to assist in determining operational parameters, such as the local areal density of the polymerizable composition to be dispensed, the target temperature, the radiation exposure temperature, the dose of actinic radiation during at least one radiation exposure operation, the total dose of actinic radiation received by the polymerizable composition for all radiation exposure operations, the post-exposure bake temperature, or another parameter used in the methods described below. As used herein, total dose is the sum of the doses used in exposing the polymerizable composition to actinic radiation. In embodiments, the total dose can be the sum of the dose used in forming the photocured planarization layer and another dose used in an optional curing process. The controller can select a target temperature associated with the heating radiation exposure based on a post-exposure bake temperature stored in memory.

[0050] In another embodiment, at least one component of system 100 , such as stations 123 , 125 , 126 and 276 , may include a local controller that provides some of the functionality provided by controller 150 or 250 .

[0051] More or fewer controllers and more or less memory may be used with system 100. In another embodiment, a single controller can perform all of the functions described with respect to controllers 150 and 250. Thus, one controller rather than two controllers may be used with system 100. In a further embodiment, controller 150 can control both the curing apparatus 101 and the bake apparatus 201, and thus controller 250 is not required, or controller 250 can control both the curing apparatus 101 and the bake apparatus 201, and thus controller 150 is not required. In another embodiment, one memory rather than two memories may be used with system 100.

[0052] In another embodiment, the heating radiation exposure station 126 may be in a different apparatus compared to the dispensing station 123. The planarizing head station 125 may be located in an apparatus that includes the heating radiation exposure station 126 or the dispensing station 123.

[0053] 3 includes a cross-sectional view of a portion of system 100 including one of heating radiation exposure stations 126. Substrate chuck 136 is coupled to positioning stage 396. Radiation head assembly 326 can include an array of one or more heat sources and one or more actinic radiation sources. Radiation head assembly 326 is described in more detail later in this specification.

[0054] The substrate chuck 136 may include an insulating section 1362, a cooling section 1364, and an insulating section 1366. Any or all of the sections 1362, 1364, and 1366 may reduce the amount of heat reaching the positioning stage 396. The positioning stage 396, the substrate chuck 136, or both may include positioning or other mechanisms designed to move to precise positions. Over time, exposure to heat or repeated heating and cooling cycles may cause the positioning or other mechanisms to drift and require recalibration, or internal features of the positioning stage 396, the substrate chuck 136, or both may warp, distort, or undergo other shape changes.

[0055] Either or both of insulating sections 1362 and 1366 can include a material with a relatively low thermal conductivity. A relatively low thermal conductivity material can have a thermal conductivity of less than 5 W / (m*K). Exemplary materials can include polymers, quartz, zirconia, yttria, cordierite, vacuum insulation panels, or aerogel. Insulating section 1362 can include an upper surface that reflects thermal radiation, such as a hot mirror, a hot mirror coating, or a hot mirror polish.

[0056] In any of the above-described or different embodiments, the surface of the insulating section 1362 facing the radiation head assembly 326 can have a relatively lower contact area with a substrate (not shown) supported by the insulating section 1362 than the opposite surface having a relatively higher contact area with the cooling section 1364. In the same or different embodiments, the surface of the insulating section 1366 facing the positioning stage 396 can have a relatively lower contact area with the positioning stage 396 than the opposite surface having a relatively higher contact area with the cooling section 1364. The insulating section 1366 is optional and may not be present in all embodiments. The cooling section 1364 can include channels or other flow paths to allow a cooling fluid to flow through the cooling section 1364. Although not shown, the substrate chuck 136 can include lift pins that can raise or lower the substrate relative to the substrate chuck 136.

[0057] The heating radiation exposure station 126 further includes a radiation head assembly 326. The radiation head assembly 326 can include an array of at least one heat source and at least one actinic radiation source. The radiation head assembly 326 can include as few as one heat source (with multiple actinic radiation sources) or one actinic radiation source (with multiple heat sources); however, to simplify the description of the radiation head assembly 326, subsequent references to the heat source and the actinic radiation source will be in the plural, even if only one heat source or one actinic radiation source is present. With reference to FIG. 3 , the actinic radiation source can emit actinic radiation 322 to photocure the polymerizable composition, and the heat source can emit heat 324 to heat the polymerizable composition to a temperature above ambient temperature. Each of the actinic radiation source and the heat source can emit radiation in a spectrum of wavelengths, and the radiation can be characterized by a peak wavelength, which is the wavelength corresponding to the highest intensity within the spectrum.

[0058] The actinic radiation source can include a lamp, light-emitting diode (LED), or laser capable of emitting actinic radiation at a wavelength or range of wavelengths tailored to activate the photoinitiator in the polymerizable composition. The actinic radiation can have a peak actinic wavelength of 10 nm to 500 nm. The actinic radiation can be ultraviolet radiation having a wavelength in the range of 100 nm to 400 nm, more specifically, in the range of 200 nm to 400 nm. The supplier of the polymerizable composition can provide a target wavelength or range of wavelengths to use to photocure the polymerizable composition.

[0059] The heat source may be a lamp, light-emitting diode (LED), or heating element capable of emitting heat with a peak heating wavelength in the range of 400 nm to 2500 nm. The wavelength used for heating may depend in part on the primary material of the substrate. The substrate may be a single-crystal semiconductor wafer or a wafer including a combination of substrate, insulator, and semiconductor layers, such as a silicon-on-insulator substrate. For the latter category, the substrate constitutes the majority of the wafer's mass. Lower thermal conductivity helps reduce the amount of heat flowing to the substrate chuck 136 or positioning stage 396. In an embodiment, the primary material of the substrate may be silicon (Si). Si has a relatively low transmittance of radiation at wavelengths less than 1200 nm. Therefore, the heat source may emit heat with a peak heating wavelength in the range of 400 nm to 1100 nm. In another embodiment, the heat source emits heat with a peak heating wavelength in the range of 500 nm to 900 nm to provide a good balance between the intensity of the radiated heat (desired) and the radiation penetrating the substrate (undesired). In this manner, the heat source can emit visible light capable of heating the substrate. In another embodiment, the substrate's primary material can be the 4H polytype of silicon carbide (4H—SiC). A 400 μm thick piece of 4H—SiC can transmit less than 50% of incident radiation at wavelengths greater than 960 nm. Thus, the heat source can emit heat with a peak heating wavelength ranging from 960 nm to 2500 nm. If one or more of the insulating sections 1362 and 1366 and the cooling section 1364 have a sufficiently robust design to keep the amount of heat reaching sensitive portions of station 126 to an acceptable level, shorter wavelength radiation can be used to heat the 4H—SiC.

[0060] The heat source can emit radiation with a relatively broad or narrow spectrum. For example, the heat source can emit radiation with a spectrum from 450 nm to 1000 nm. A different type of heat source may emit radiation with a spectrum from 450 nm to 700 nm. Additional types of heat sources, such as light-emitting diodes, may emit radiation with a spectrum from 400 nm to 650 nm. If necessary or desired, a filter can be placed between the heat source and the workpiece containing the polymerizable composition to narrow the range of wavelengths of radiation reaching the workpiece. In another embodiment, a filter can be placed between the workpiece and the observation tool to allow the observation tool to receive a wavelength or a relatively small range of wavelengths. In the same or a different embodiment, the heat source can emit heat at a peak heating wavelength that is different from the peak actinic wavelength corresponding to the actinic radiation source. In certain embodiments, the peak heating wavelength can be longer than the peak actinic wavelength. In a non-limiting example, the peak heating wavelength can be 700 nm and the peak actinic wavelength can be 300 nm.

[0061] The actinic radiation source may be configured to emit radiation at only one power level when activated, or may be configured to emit radiation at two or more power levels when activated. The heat source may be configured to emit heat at only one power level when activated, or may be configured to emit heat at two or more power levels when activated.

[0062] The radiation exposure station 126 can further include a temperature sensor (not shown) within the substrate chuck 136 or a proximity temperature sensor (not shown). The temperature sensor within the substrate chuck 136 can be positioned so that it is in contact with the substrate or in close proximity (e.g., within 1 mm) to the substrate when the substrate is positioned on the substrate chuck 136. The proximity temperature sensor can receive near-infrared radiation from the substrate, polymerizable composition, or superstrate to determine the temperature of the substrate, polymerizable composition, or superstrate.

[0063] FIG. 4 includes a bottom-up view of a portion of the radiation head assembly 326, including the actinic radiation sources 422 and the heat sources 424. The dashed line 436 corresponds to the shape of the substrate-holding surface of the substrate chuck 136. As shown in FIG. 4, the actinic radiation sources 422 and the power sources 424 are arranged in alternating, substantially concentric circles, with each circle including all of the actinic radiation sources 422 and no power sources 424, or all of the power sources 424 and no actinic radiation sources 422. In another embodiment, at least one actinic radiation source 422 and at least one heat source 424 are arranged along the same circle. FIG. 5 includes a bottom-up view of a portion of the radiation head assembly 326, including the actinic radiation sources 422 and the heat sources 424, alternating along the circle. In an alternative embodiment, the radiation head assembly 326 is incorporated into the planarization head station 125, instead of a separate heating radiation exposure station 126, forming a planarization and heating radiation station. The planarizing and heating radiation station includes a radiation head assembly 326 that emits radiation through the planarizing head 135 .

[0064] Figures 6 and 7 include bottom-up views of a portion of a radiation head assembly including alternating rows of actinic radiation sources 422 and heat sources 424. Figure 6 has a linear pattern of actinic radiation sources 422 and heat sources 424. Figure 7 has a hexagonal pattern of actinic radiation sources 422 and heat sources 424. In Figure 7, the rows of heat sources 424 are offset in the X direction by half the pitch of the actinic radiation sources 422 in their immediately adjacent rows. Figures 8 and 9 are similar to Figures 6 and 7, except that the rows of actinic radiation sources 422 and the rows of heat sources 424 have been replaced by a checkerboard of actinic radiation sources 422 and heat sources 424. In Figure 9, each row of actinic radiation sources 422 and heat sources 424 is offset in the X direction by half the pitch of the actinic radiation sources 422 and heat sources 424 in its immediately adjacent row.

[0065] The heat source can be in the form of a heating element as shown in Figure 10. The configuration of actinic radiation source 422 is the same as that shown in Figure 4. Point heat source 424 is replaced by heat source 1024. Heat source 1024 can include a resistive element capable of releasing heat when a current passes through the resistive element.

[0066] Many other patterns for the array of actinic radiation sources 422 and heat sources 424 can be used without departing from the concepts described herein. In embodiments, as shown in FIGS. 4 through 10 , the numerical ratio of actinic radiation sources 422 to heat sources 424 can be 1:1. In other embodiments, the ratio of the number of actinic radiation sources 422 to the number of heat sources 424 can vary from 1:1. For example, the intensity of the radiation emitted by the actinic radiation sources 422 can be significantly different from the intensity of the heat emitted by the heat sources 424. The ratio of the number of actinic radiation sources 422 to the number of heat sources 424 can range from 5:1 to 1:5. For heat sources 1024, the ratio of actinic radiation sources 422 to heat sources 1024 can vary substantially, such as from 500:1 to 10:1. The ratio of actinic radiation sources to heat sources can be greater or less than those described herein.

[0067] Many alternative embodiments for the system and equipment may be used. The number of stations of each type may differ from those shown to increase throughput or as needed or desired for the particular physical design of the device or stations within the device. For example, two or more planarization head stations 125 may be used. When at least two planarization head stations are used, either (1) all planarization head stations are used between the dispensing and curing operations, or (2) at least one planarization head station is used between the dispensing and curing operations and at least one other planarization head station is used after one curing operation. For each type of station, the number and location of the stations may be tailored to the particular application. Each planarization head station shares a positioning stage with at least one heating radiation exposure station.

[0068] Functions described with respect to a particular station may be performed by a different station. As noted above, functions associated with the planarizing head station 125 may be incorporated into the dispensing station 123 or the radiation exposure station 126, and thus the planarizing head station 125 may not be necessary. In another embodiment, exposure to actinic radiation occurs at two or more temperatures. In this embodiment, the heating radiation exposure station 126 may heat the pre-cured layer to a first temperature before curing, and an optional radiation exposure station may heat the cured planarizing layer to a second temperature where further curing occurs. In a further embodiment, different exposures to actinic radiation may be performed within the same radiation exposure station. For example, radiation exposure at a lower temperature may be performed within the same radiation station, and the substrate and pre-cured layer may be heated to a higher temperature and exposed to actinic radiation at the higher temperature. Before exposing the next substrate and pre-cured layer, the radiation exposure station may be cooled to approach a lower temperature. However, cooling may adversely affect system throughput, or a greater number of radiation exposure stations may be used to maintain consistent system throughput. After reading this specification, one skilled in the art will be able to determine the type and number of radiation exposure stations to use.

[0069] The selection of more or fewer devices and which stations are within each device can be tailored to the specific application. Stations 123, 125, and 126 may be within the same device to reduce process variability. The optional curing station may be within a different device. The optional curing station may be within bake apparatus 201. Thermal insulation may be used between the optional radiation exposure station and bake station 276, or heating radiation exposure station 126 may be located sufficiently far from bake station 276 so that heat emitted by bake station 276 does not interfere with temperature control within heating radiation exposure station 126. Thermal insulation may be used between heating radiation exposure station 126 and one or both of dispensing station 123 and the planarizing head station. In further embodiments, the heating radiation exposure station may be within its own device and not shared with any of stations 123, 125, and 276. In yet other embodiments, the number of devices depends on the layout within the room in which the devices are located, facility connections, or both. After reading this specification, one skilled in the art will be able to understand the number, design and location of devices for a particular system.

[0070] Attention is now directed to a method of forming a baked planarization layer on a substrate using system 100. FIG. 11 includes a process flow diagram of the method described with respect to any of the systems shown and described with respect to FIGS. 1 through 9. Specific process flows are described below in conjunction with the drawings and are directed to an IAP process. Many different process flows can be used and can achieve benefits using the concepts described herein. As used below, an unpatterned superstrate is referred to as a blank, and a patterned superstrate is referred to as a template. Other variations on the process flow are described later in this specification. At least some features in FIGS. 12 through 17, 27, and 28 are not drawn to scale to allow for a better understanding of such features and other features in relation to the described method.

[0071] 1 and 12 , the method may include transferring a substrate from a substrate pod 121 to a dispense station 123. The controller 150 or a local controller may signal the substrate transfer tool 110 to remove the substrate 1202 from the substrate pod 121 and move the substrate 1202 to the dispense station 123. The substrate transfer tool 110 may place the substrate 1202 on a substrate chuck 133 in the dispense station 123.

[0072] The method can include dispensing a polymerizable composition onto a substrate at block 1122 of Figure 11. The polymerizable composition can include a polymerizable material and a photoinitiator. The polymerizable composition can include or can be solvent-free. In further embodiments, the polymerizable composition can contain other additives. Non-limiting examples of other additives can be surfactants, dispersants, stabilizers, inhibitors, dyes, or combinations thereof.

[0073] 1 and 12, dispense head 146 dispenses droplets 1222 of polymerizable composition onto the exposed surface of substrate 1202, as shown in Figure 12. During the dispense operation, substrate chuck 133 can be coupled to a positioning stage 1296 configured to move substrate chuck 133 during the dispense operation (shown by the arrow adjacent to substrate 1202 in Figure 12). In another embodiment, dispense head 146 moves while substrate chuck 133 remains stationary, and in a further embodiment, both substrate chuck 133 and dispense head 146 move during dispense.

[0074] Substrate 1202 can have an exposed surface with protrusions located at a relatively high elevation compared to adjacent recesses. In FIG. 12 , the exposed surface of substrate 1202 has protrusions 1242 and recesses 1244. Substrate 1202 has localized regions with a relatively high areal density of protrusions 1242 compared to recesses 1244 and other localized regions with a relatively high areal density of recesses 1244 compared to protrusions 1242. A lower areal density of polymerizable composition is dispensed, where protrusions 1242 occupy a relatively large proportion of the localized region, and a higher areal density of polymerizable composition is dispensed, where recesses 1244 occupy a relatively large proportion of the different localized region. In reality, the exposed surface of substrate 1202 is more complex than shown in FIG. 12 and is not limited to just two elevations. In FIG. 12 , the exposed surface of substrate 1202 is simplified to aid in understanding the concepts described herein.

[0075] The controller 150 or a local controller can send signals to move the dispensing head 146, the positioning stage 1296 coupled to the substrate chuck 133 (if the substrate chuck 133 is coupled to the positioning stage), or both, in a desired direction and speed, so that the dispensing head 146 dispenses droplets 1222 of the polymerizable composition at a desired rate to achieve an appropriate local areal density of the polymerizable composition along the exposed surface of the substrate 1202.

[0076] 1 , 12, and 13 , after the droplets 1222 of the polymerizable composition are dispensed, the substrate 1202 and the droplets 1222 of the polymerizable composition can be moved from the dispense station 123 to the planarization head station 125. The controller 150 or a local controller can send a signal to the substrate transfer tool 110 to move the substrate 1202 and the droplets 1222 of the polymerizable composition from the dispense station 123 to the planarization head station 125 and onto the substrate chuck 136 coupled to the positioning stage 396. Referring to FIGS. 1 and 13 , before the substrate 1202 and droplets 1222 are transferred to the planarization head station 125, if the positioning stage 396 and the substrate chuck 136 are not at the planarization head station 125, the positioning stage 396 and the substrate chuck 136 are moved from the heating radiation exposure station 126 to the planarization head station 125.

[0077] The process further includes contacting the polymerizable composition with a superstrate at block 1124 of Figure 11. Referring to Figure 12, the superstrate 1392 can be used to aid in forming a pre-cured layer from the droplets 1222 of the polymerizable composition. In an embodiment, the superstrate 1392 can be a blank having a flat bottom surface facing the substrate 1202 and the droplets 1222. The planarization head station 125 can include a superstrate handler (not shown) that can be used to move and position the superstrate 1392. In the same or a different embodiment, the superstrate 1392 can be held by a planarization head in the radiation exposure station 126.

[0078] The superstrate 1392 has a transmittance of at least 70%, at least 80%, at least 85%, or at least 90% to the actinic radiation used to photocure the polymerizable composition. The superstrate 1392 can include a glass-based material, an organic polymer, a siloxane polymer, a fluorocarbon polymer, sapphire, spinel, silicon, a metal, 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 radiation can be ultraviolet radiation and a glass-based material can be used for the superstrate 1392. The superstrate 1392 can have a thickness ranging from 30 microns to 2000 microns. The contact surface of superstrate 1392 can have a surface area that is at least 90%, 95%, 96%, 97%, or 99% of the area of ​​substrate 1202, and can have a surface area the same as or greater than substrate 1202. Superstrate 1392 can have a gas-absorbing layer with a low surface energy relative to the photocured planarizing layer that reduces the separation force between the superstrate and the photocured planarizing layer.

[0079] The contact surface of the superstrate 1392 has a two-dimensional shape, including a circle, an oval, a rectangle (including a square), a hexagon, etc. The two-dimensional shape may be the same as the outer shape of the substrate 1202. For example, both can be circles. In the embodiment shown in FIG. 13, the contact surface does not have recesses or protrusions.

[0080] 1, 13, and 14, controller 150 or a local controller can send a signal to bring superstrate 1392 and droplets 1222 into close proximity and contact with one another. Superstrate 1392 can move, substrate chuck 136 can move, or both superstrate 1392 and substrate chuck 136 can move. As superstrate 1392 contacts droplets 1222 of polymerizable composition, droplets 1222 can coalesce and form a pre-cured layer 1422 of polymerizable composition. A top surface 1412 of pre-cured layer 1422 conforms to the bottom, contacting surface of superstrate 1392.

[0081] 1 and 14 , a positioning stage 396 coupled to the substrate chuck 136 can transport the substrate 1202 and the pre-cured layer 1422 from the planarization head station 125 to the heating radiation exposure station 126. The controller 150 or a local controller can send signals to the positioning stage 396 to move the substrate chuck 136, the substrate 1202, and the pre-cured layer 1422 from the planarization head station 125 to the radiation exposure station 126.

[0082] The process further includes heating the pre-cured layer at block 1142 of Figure 11 and exposing the pre-cured layer to actinic radiation to form a photocured planarizing layer at block 1144 of Figure 11. With reference to Figures 15-17, a heat source 424 is activated and an actinic radiation source 422 is deactivated to emit heat 324 that reaches the workpiece, including the substrate 1202, the pre-cured layer 1422, and the superstrate 1392 (Figure 15); an actinic radiation source 422 and a heat source 424 are activated to emit actinic radiation 322 and heat 324 that reach the workpiece (Figure 16); and an actinic radiation source 422 is activated and a heat source is deactivated to emit actinic radiation 322 that reaches the workpiece (Figure 17). Heating can begin before, simultaneously with, or after initiating exposure of the pre-cured layer 1422 to actinic radiation. The timing of activating, deactivating, and power levels while active for actinic radiation source 422 and heat source 424 is described later in this specification with respect to Figures 18 through 26. The following discussion will discuss considerations for heating and exposing pre-cured layer 1422 to actinic radiation before describing the timing diagrams.

[0083] Heating the pre-cured layer 1422 can help reduce the amount of thickness variation that occurs due to photocuring and baking of the polymerizable composition in the pre-cured layer 1422. The temperature to be achieved in the pre-cured layer 1422 depends on whether heating is terminated or reduced before the pre-cured layer 1422 is exposed to actinic radiation, or whether heating is continued during exposure to actinic radiation. If heating is terminated before exposing the pre-cured layer 1422 to actinic radiation, the target temperature may be higher than the desired radiation exposure temperature to account for cooling between the time heating is terminated and some time between subsequent exposures, such as at the beginning, middle, end, or another time of exposure. If heating continues during exposure, the target temperature may or may not be the same as the desired radiation exposure temperature.

[0084] The desired radiation exposure temperature may be above room temperature, up to 95°C, up to 85°C, or up to 80°C. The desired radiation exposure temperature can range from 25°C to 95°C, 30°C to 85°C, or 35°C to 80°C. The target temperature for heating can be the same as the desired radiation exposure temperature or a few degrees higher. The target temperature can be from 25°C to 98°C, 30°C to 88°C, or 35°C to 83°C. The desired radiation exposure temperature can be set based on baking information including at least one of the following: baking temperature, desired baking temperature, composition of the pre-cured layer, experimentally determined relative thickness change of the pre-cured layer after baking, experimentally determined relative thickness change of the photo-cured planarizing layer after baking, and planarization performance after baking.

[0085] During heating, a temperature sensor can be used to monitor the temperature of the pre-cured layer 1422 by measuring the temperature of the pre-cured layer 1422, the substrate 1202, or the superstrate 1392. Since the substrate 1202 and the superstrate 1392 each have a substantially larger mass than the pre-cured layer 1422, the temperature of the substrate 1202 or the superstrate 1392 is used to determine the temperature of the pre-cured layer 1422. The controller 150 or the local controller can receive the temperature data from the temperature sensor, and the controller 150 or the local controller can send a signal to the heat source 424 to heat the substrate 1202 and the pre-cured layer 1422 to a target temperature. The signal can include activation information and, if the heat source 424 is capable of operating at multiple power levels, can include power level information. After the pre-cured layer 1422 reaches the target temperature, the controller 150 or the local controller can send a signal to the heat source 424 to terminate or continue heating the pre-cured layer 1422 at the target temperature.

[0086] With respect to exposing the pre-cured layer to actinic radiation to form a photo-cured planarizing layer, for a particular polymerizable composition, memory 152 ( FIG. 1 ) can contain information regarding a target wavelength or range from the wavelength of the actinic radiation, a target total dose or range from the total dose used in the polymerizable composition, a dose used when exposing pre-cured layer 1422 to actinic radiation to form the photo-cured planarizing layer, or other data related to exposing the polymerizable composition to actinic radiation. Such information is used by controller 150 or a local controller to determine parameters for exposing pre-cured layer 1422 to actinic radiation. During curing, the polymerizable composition can be at a desired radiation exposure temperature ±3°C. The temperature at the time of the heating radiation exposure is referred to herein as the actual radiation exposure temperature. The actual radiation exposure temperature can be at or near the desired radiation exposure temperature. The actual radiation exposure temperature can be any of the target temperatures and tolerance ranges described above.

[0087] The controller 150 or local controller can receive a signal from the temperature sensor, or a derivative of such a signal, and determine whether the temperature is at the desired radiation exposure temperature or within an acceptable range of the desired radiation exposure temperature (e.g., ±5°C, ±2°C, ±1°C, or ±0.5°C). When the temperature is at the desired radiation exposure temperature or within an acceptable range of the desired radiation exposure temperature, the controller 150 or local controller can send a signal to the actinic radiation source 422 to activate, as shown in FIG. 16 or 17. The signal can include activation information and, if the actinic radiation source 422 is capable of operating at more than one power level, can include power level information.

[0088] Most of the exposure to actinic radiation occurs when the pre-cured layer 1422 is at or above 50° C. The timing at which the actinic radiation source 422 and heat source 424 are activated and deactivated, and the power levels if the sources are capable of operating at more than one power level, are better understood with reference to the timing diagrams in Figures 18 through 26. In Figures 18 through 26, the power level of the emitted radiation or heat is proportional to the vertical dimension of the actinic radiation 322 or heat 324, as shown in the timing diagrams. Rectangles represent constant power levels over time, and triangles represent power levels that decrease or increase as a function of time.

[0089] 18, heat source 424 is activated to emit heat when actinic radiation source 422 is deactivated. Actinic radiation source 422 is activated to emit actinic radiation after initiating heating. Both actinic radiation source 422 and heat source 424 are activated for a period of time, after which heat source 424 is deactivated. After a further period of time, actinic radiation source 422 is deactivated.

[0090] FIG. 19 can be used with actinic radiation source 422 and heat source 424 that can operate at two or more power levels. In FIG. 19, heat source 424 is activated to emit heat, and the power level of heat source 424 decreases as a function of time. Actinic radiation source 422 is activated to emit actinic radiation at or shortly after heat source 424 is activated. The power level of actinic radiation source 422 increases as a function of time until a constant power level is achieved. Actinic radiation source 422 remains at a constant power level for another period of time before actinic radiation source 422 is deactivated. During the particular period shown in FIG. 19, the power level of heat source 424 supplied decreases, while the power level of actinic radiation source 422 increases.

[0091] Figure 20 is similar to Figure 18, except that neither actinic radiation source 422 nor heat source 424 is activated for any particular period of time. Actinic radiation source 422 is activated at or after heat source 424 is deactivated.

[0092] Figures 21 and 22 are similar to Figure 18, except that the power level of the heat source in Figure 21 is reduced at approximately the same time that heat source 424 in Figure 18 is deactivated. In Figure 21, the power level of heat source 424 is reduced to zero or deactivated at the time actinic radiation source 422 is deactivated. Figure 22 is similar to Figure 21, except that the power level of heat source 424 is reduced to zero or deactivated after actinic radiation source 422 is deactivated. In another embodiment (not shown), the power level of heat source 424 can be reduced to zero or deactivated before actinic radiation source 422 is deactivated.

[0093] 23, heat source 424 is activated to heat the substrate, which heats pre-cured layer 1422, and the power level of heat source 424 is decreased as a function of time. Actinic radiation source 422 is activated to emit actinic radiation at or shortly after heat source 424 is activated. The power level of actinic radiation source 422 remains constant until actinic radiation source 422 is deactivated.

[0094] FIG. 24 is similar to FIG. 19 , except that the actinic radiation source 422 is activated before the heat source 424 is activated. Furthermore, during the power transition period, the power level of the actinic radiation source 422 increases more gradually as a function of time compared to FIG. 19 . In this manner, exposure of the pre-cured layer 1422 to actinic radiation can begin before heating begins. Heating the pre-cured layer 1422 helps reduce the amount of thickness change, typically shrinkage, that occurs during exposure to actinic radiation and baking. The dose of actinic radiation emitted from the actinic radiation source 422 is below a threshold when the polymerizable composition is below the target temperature. Thus, before the heat source 424 is activated, the dose of actinic radiation emitted from the actinic radiation source 422 can be up to 60% of the total dose of actinic radiation during the exposure operation. To help maintain a relatively low thickness change, up to 9%, 5%, or no dose occurs before the heat source 424 is activated.

[0095] The heat source 424 may be designed to function at only one power level. FIG. 25 is similar to FIG. 20 except that after initial heating, the heat source 424 is activated and deactivated for relatively short periods (hereinafter "heat pulses") to help maintain the temperature of the pre-cured layer 1422 more constant than if heat pulses were not used. The number of heat pulses may be greater or less than shown. In the same or different embodiments, the time pulses or time periods between heat pulses may be different from those shown in FIG. 25. Heating operation as shown in FIG. 25 can be used with a heat source 424 that can operate at two or more power levels, although the heat source 424 need not be at different power levels when activated.

[0096] The heating operation in Figure 26 can be used when the heat source 424 is capable of operating at two or more power levels. Figure 26 is similar to Figure 25, except that the heat pulse has a power level for the heat source 424 that varies as a function of time. In Figure 26, during the heat pulse, the power level of the heat source 424 decreases as a function of time. In another embodiment, during one or both of the heat pulses, the power level of the heat source 424 may increase as a function of time, or the power level may be substantially constant for a portion of the heat pulse before the power level decreases, after the power level increases, or a combination thereof.

[0097] With reference to Figures 25 and 26, one skilled in the art can determine for a particular application whether heat pulses are used, the number of heat pulses, the duration of the heat pulses, the power level of the heat pulses, and the time between heat pulses.

[0098] The energy from exposure to actinic radiation forms the photocured planarizing layer 2722 shown in FIG. 27. The energy polymerizes the polymerizable material, forming covalent bonds between the polymeric material or adjacent molecules to form crosslinked materials. The polymeric material may be a single polymer compound or a copolymer. Exposure to actinic radiation during the thermal radiation exposure substantially polymerizes, but does not fully polymerize, the polymerizable material in the photocured planarizing layer 2722. In embodiments, further exposure to actinic radiation may not occur. Further polymerization may occur during a post-exposure bake of the photocured planarizing layer 2722 due to thermal curing.

[0099] After the photocured planarization layer 2722 is formed, the superstrate 1392 can be removed. Referring to Figures 1 and 27, in an embodiment, the superstrate 1392 can be removed within the planarization head station 125. The controller 150 or a local controller can send a signal to the positioning stage 396 to move it from the heating radiation station 126 to the planarization station 125.

[0100] The method can include removing the superstrate from the photocured planarizing layer at block 1162 of FIG. 11 . The polymerizable composition can include an internal release agent that remains in the photocured planarizing layer 2722 after polymerization. The internal release agent helps reduce the likelihood of damaging or removing part or all of the photocured planarizing layer 2722 when removing the superstrate 1392. The superstrate 1392 can also include a release agent. The controller 150 or a local controller can send a signal to the planarizing head 135 to remove the superstrate 1392 from the photocured planarizing layer 2722.

[0101] In another embodiment, the superstrate 1392 can be removed within the heating radiation station 126. Thus, the positioning stage 396 can remain within the heating radiation station 126 while the superstrate 1392 is removed.

[0102] The method can include moving the substrate 1202 and the photo-cured planarizing layer 2722 from the curing apparatus 101 to the bake apparatus 201. Referring to FIG. 1 , the controller 150 or a local controller can signal the substrate transfer tool 110 to remove the substrate 1202 and the photo-cured planarizing layer 2722 from the planarizing head station 125 and move the substrate 1202 and the photo-cured planarizing layer 2722 to the substrate pod 121 or another substrate pod. The substrate pod 121 or other substrate pod can be moved to the bake apparatus 201 for further processing. In another embodiment, the substrate 1202 and the photo-cured planarizing layer 2722 can be moved to the substrate pod 271 in FIG. 2. The substrate transfer tool 210 can place the substrate 1202 on a substrate chuck 286 in one of the post-exposure bake stations 276.

[0103] The method may include baking the photo-cured planarizing layer to form a baked planarizing layer at block 1182 of Figure 11. During the baking operation, the material in the photo-cured planarizing layer 2722 may be further polymerized, cross-linked, or both. The baking operation may also serve to remove relatively volatile components, if present, from the photo-cured planarizing layer 2722 in forming the baked planarizing layer 2802 in Figure 28. The baked planarizing layer 2802 has an upper surface 2812.

[0104] A heating means in the post-exposure bake station 276 can be used to heat the photocured planarizing layer 2722 ( FIG. 27 ) to form a baked planarizing layer 2802 ( FIG. 28 ). The heating means can include a resistive heating element, a radiative heating element, or a gas flow system (e.g., a heater and fan) that provides heated gas for convection heating. FIG. 28 shows a resistive heating element 2822 in the substrate chuck 286 and a radiative heating element 2824 positioned above the substrate chuck 286. The heating means provides heat at a temperature higher than that used in the heating radiation exposure operation. The baking temperature can be at least 300°C, at least 325°C, or at least 350°C. The baking temperature should not be so high as to cause significant decomposition or other adverse effects on the baked planarizing layer 2802. The baking temperature can be up to 500°C, up to 450°C, or up to 400°C. The baking temperature can be any value between the minimum and maximum numbers listed above, such as 300° C. to 500° C., 300° C. to 450° C., or 300° C. to 400° C. In certain embodiments, the baking temperature can range from 350° C. to 400° C.

[0105] The soak time is the time that the substrate 1202 and the overlying polymer layer are at the bake temperature. The soak time should be sufficient to achieve the necessary or desired amount of further polymerization or crosslinking, to reduce the amount of volatile components in the polymer layer to the desired amount, or both. The soak time can be 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 (a sufficient amount of polymerization or crosslinking has occurred, the remaining amount of volatile components is low enough not to cause problems during subsequent processing, etc.) or may cause adverse effects, such as roughening of the top surface 2812 of the baked planarization layer 2802 or possible delamination of the baked planarization layer 2802 from the substrate 1202. The soak time may be up to 30 minutes, up to 20 minutes, or up to 15 minutes. The immersion time can range between the minimum and maximum values ​​stated above, for example, from 0.25 minutes to 30 minutes, from 1 minute to 20 minutes, or from 3 minutes to 15 minutes.

[0106] The baking operation can be performed using a gas. The gas can include a material that is relatively inert with respect to the photo-cured planarizing layer 2722 and the baked planarizing layer 2802. The material can include N, CO, a noble gas (Ar, He, etc.), or a mixture thereof. The gas can be free of oxidizing substances, such as O, O, N, O, etc., or can include less than 2 mol % or less than 0.5 mol % of oxidizing substances.

[0107] As shown, the post-exposure bake station 276 is configured to process a single substrate at a time. In another embodiment, the post-exposure bake station 276 can be configured to process multiple substrates during the same baking operation. The post-exposure bake station 276 can include or be capable of receiving a cassette or other suitable substrate container, which can hold multiple substrates.

[0108] The memory 252, database, or another memory external to the post-exposure bake apparatus 201 can contain information regarding the composition of the polymer precursor used to form the photo-cured planarizing layer 2722, the desired bake temperature, the desired soak time for forming the baked planarizing layer 2802, or a combination thereof. Referring to FIG. 2, the controller 250 or a local controller can send a signal to the post-exposure bake station 276 to flow an inert gas through the post-exposure bake station 276 and control a heating means to maintain the substrate 1202 and the photo-cured planarizing layer 2722 at the desired bake temperature or within a tolerance range for the soak time. The tolerance range can be ±10°C, ±5°C, or ±2°C of the desired bake temperature. Referring to FIG. 28, during heating, the controller 250 or local controller can receive temperature data from a temperature sensor (not shown) in the substrate chuck 286 or a proximal temperature sensor (not shown). A temperature sensor in substrate chuck 286 can be positioned in contact with or in close proximity (e.g., within 1 mm) to substrate 1202 when the substrate is positioned on substrate chuck 286. Referring to Figures 27 and 28, the proximity temperature sensor can receive near-infrared light from substrate 1202 or photo-cured planarizing layer 2722 to determine the temperature of substrate 1202 or photo-cured planarizing layer 2722.

[0109] The controller 250 or a local controller can send signals to a heating means, such as a resistive heating element 2822 or a radiative heating element 2824, to heat the substrate 1202 and the photocured planarization layer 2722 to a baking temperature or to maintain the temperature in the post-exposure bake station 276 at a baking temperature.

[0110] After the soak time, the controller 250 or a local controller can signal the heating means and the substrate transfer tool 210 to be deactivated in order to remove the substrate 1202 and baked planarizing layer 2802 from the post-exposure bake station 276. The substrate 1202 and baked planarizing layer 2802 can be moved by the substrate transfer tool 210 to a cooling plate to reduce the temperature of the substrate 1202 and baked planarizing layer 2802 before the substrate 1202 and baked planarizing layer 2802 are returned to the substrate pod 271. After cooling is complete, the controller 250 or a local controller can send a signal to move the substrate 1202 and baked planarizing layer 2802 to the substrate pod 271. In an alternative embodiment, the system 100 does not include an additional substrate transport tool 210 and substrate pod 271, and the substrate transport tool 110 is configured to transport at least one substrate having a photo-hardened planarizing layer to the post-exposure bake station 276, and the substrate transport tool can then move the substrate with the baked planarizing layer 2802 to the substrate pod 121.

[0111] After reading this specification, one skilled in the art will understand that many system configurations and process options are available without departing from the concepts described herein, and one skilled in the art will be able to determine the particular system configuration and the particular method to use to meet the needs or desires of a particular application.

[0112] The above-described process can be used to form a planarization layer from a polymerizable composition. The above-described process can be integrated as part of a manufacturing method for producing an article. The article can be an electrical circuit element, an optical element, a microelectromechanical system (MEMS), a recording element, a sensor, a mold, an electro-optical element, a microfluidic element, a piezoelectric element, a thermoelectric element, a spintronic element, a superconducting element, an integrated circuit, or the like. The integrated circuit can be a solid-state memory (dynamic random access memory (DRAM), static random access memory (SRAM), flash memory, or magnetoresistive random access memory (MRAM)), a microprocessor, a microcontroller, a graphics processing unit, a digital signal processor, a field-programmable gate array (FPGA), a semiconductor element, a power transistor, a charge-coupled device (CCD), an image sensor, an application-specific integrated circuit (ASIC), or the like.

[0113] The method may further include exposing the substrate 1202 and baked planarization layer 2802 to other processes for device (article) fabrication, including, for example, curing, oxidation, layer formation, deposition, doping, additional planarization, lithography, etching, moldable material removal, dicing, bonding, and packaging, etc. The substrate may be processed to fabricate multiple articles (devices), for example, the substrate may be a semiconductor wafer.

[0114] In alternative embodiments, more than one radiation exposure may be performed. For example, another radiation exposure may be performed at room temperature before the heating radiation exposure described above. The other radiation exposure may be performed in radiation exposure station 126 before heating for the heating radiation exposure, or may be performed in a separate radiation exposure station. In another example, the other radiation exposure may be performed between the heating radiation exposure and the baking operation. After reading this specification, one skilled in the art will be able to determine the number of radiation exposures, environmental conditions (e.g., temperature and areal radiation density), and number of radiation exposure stations to be used for a particular application.

[0115] The embodiments described herein may allow for greater flexibility in heating and exposure operations, allowing the system 100 to occupy a smaller area. The actinic radiation source and heat source may be integrated into an array within the radiation head assembly. Separate stations for heating and exposing the pre-cured layer of the polymerizable composition are not required. The array of actinic radiation and heat sources allows for greater flexibility in heating and exposing the pre-cured layer to actinic radiation. The heat source may be activated before, simultaneously with, or after activating the actinic radiation source. The actinic radiation source may be deactivated before, simultaneously with, or after deactivating the heat source. After the initial heating, a heating pulse may be used to help maintain the actual temperature of the pre-cured layer within a narrow range compared to when no heating pulse is used. The actinic radiation source, heat source, or actinic radiation and heat source may be configured to operate at two or more power levels. Thus, the amount of actinic radiation, heat, or both may be varied as a function of time.

[0116] It should be noted that in the general descriptions or examples, not all of the operations described above may be required, some of the specific operations may not be required, and one or more additional operations may be performed in addition to those described. Furthermore, the order in which the operations are listed is not necessarily the order in which they are performed.

[0117] Benefits, other advantages, and solutions to problems have been described above with respect to specific embodiments. However, the benefits, advantages, solutions to problems, and any features that give rise to or make more pronounced any benefit, advantage, or solution should not be construed as critical, required, or essential features of any or all of the claims.

[0118] The specification and illustrations of the embodiments described herein are intended to provide a general understanding of the structures of various embodiments. The specification and illustrations are not intended to be an exhaustive or comprehensive description of all of the elements and features of apparatus and systems that use the structures or methods described herein. Separate embodiments may be provided in combination in a single embodiment, and conversely, various features that are described for brevity in the context of a single embodiment may also be provided separately or in any subcombination. Furthermore, 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 only after reading this specification. Other embodiments can be used and derived from this disclosure, such that structural substitutions, logical substitutions, or other changes are made without departing from the scope of the disclosure. Accordingly, the disclosure is to be considered illustrative and not restrictive.

Claims

1. 1. A system comprising: at least one heat source configured to emit heat at a peak heating wavelength and to heat a stack including a superstrate, a substrate, and a polymerizable composition between the superstrate and the substrate; at least one actinic radiation source configured to emit actinic radiation at a peak actinic wavelength and photocure at least the polymerizable composition to form a photohardened planarizing layer; and the peak heating wavelength is different from the peak actinic wavelength; A system characterized by:

2. 10. The system of claim 1, wherein the peak heating wavelength is greater than the peak actinic wavelength.

3. 10. The system of claim 1, wherein the at least one heat source is configured to emit heat at the peak heating wavelength in the range of 400 nm to 2500 nm.

4. 4. The system of claim 3, wherein the peak heating wavelength is in the range of 400 nm to 1100 nm.

5. 4. The system of claim 3, wherein the peak heating wavelength is in the range of 960 nm to 2500 nm.

6. 4. The system of claim 3, wherein the at least one actinic radiation source is configured to emit actinic radiation at the peak actinic wavelength of at least 10 nm and less than 400 nm.

7. The system of claim 1 , wherein the at least one heat source comprises a plurality of point heat sources.

8. The system of claim 1 , wherein the at least one heat source comprises at least one resistive heating element.

9. a bake station configured to bake the substrate and the photocured planarization layer; a controller configured to receive bake station information and send a signal to the at least one heat source based on the bake station information; 10. The system of claim 1, further comprising:

10. a stage configured to move the substrate; a first heat insulating member disposed between the stage and the at least one heat source; 10. The system of claim 1, further comprising:

11. further comprising cooling means configured to reduce the amount of heat from the at least one heat source reaching the stage; the cooling means is disposed between the stage and the first heat insulating member. The system of claim 10.

12. Further comprising a second insulating member, The cooling means is disposed between the first heat insulating member and the second heat insulating member. The system of claim 11 .

13. a stage configured to move the substrate; a substrate chuck configured to support the substrate and positioned between the stage and the at least one heat source; 10. The system of claim 1, further comprising:

14. The substrate chuck includes: cooling means configured to reduce the amount of heat from the at least one heat source reaching the stage; 14. The system of claim 13, comprising:

15. The substrate chuck includes: an insulating member for reducing the amount of heat from the at least one heat source reaching the stage; 15. The system of claim 14, further comprising:

16. 1. A method comprising: heating a stack to a target temperature with at least one heat source, the at least one heat source emitting heat at a peak heating wavelength, the stack including a substrate, a superstrate, and a polymerizable composition disposed between the superstrate and the substrate, and an array including the at least one heat source and at least one actinic radiation source; curing the polymerizable composition to form a photocured planarizing layer, wherein curing occurs by exposing the stack to radiation emitted by the at least one actinic radiation source, the at least one actinic radiation source emitting actinic radiation at a peak actinic radiation wavelength; and and the peak heating wavelength is different from the peak actinic wavelength; A method characterized by:

17. During warming up, the stack is positioned on a substrate chuck; the substrate chuck is coupled to a stage; the temperature of the stage is less than a threshold when the stack is at the target temperature; 17. The method of claim 16.

18. 18. The method of claim 17, further comprising activating cooling means disposed between the stack and the stage during heating, curing, or both.

19. 18. The method of claim 17, further comprising: moving the stack while the polymerizable composition is cured and at a temperature above ambient temperature.

20. 17. The method of claim 16, wherein when the polymerizable composition is below the target temperature, the dose of actinic radiation emitted from the at least one actinic radiation source is below a threshold value.

21. baking the substrate and the photocured planarization layer at a baking temperature to form a baked planarization layer; during curing, the polymerizable composition is at a desired radiation exposure temperature ±3°C, the desired radiation exposure temperature being selected based at least in part on the bake temperature; 17. The method of claim 16.

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