Freezeless method for self-aligned double patterning

Abstract

A method of patterning a substrate includes depositing an overcoat in openings of a relief pattern. The relief pattern includes a solubility-altering agent and a deprotectable monomer that is sensitive to the solubility-altering agent. The overcoat includes another deprotectable monomer that is sensitive to the solubility-altering agent. The solubility threshold of the overcoat relative to a predetermined developer is lower than the solubility threshold of the relief pattern relative to the developer. The method includes activating the solubility-altering agent to at least the solubility threshold of the overcoat without reaching the solubility threshold of the relief pattern, diffusing the solubility-altering agent from structures of the relief pattern a predetermined distance into the overcoat to form soluble regions in the overcoat, and developing the substrate with a developer to remove the soluble regions of the overcoat. The soluble regions are soluble in the developer while the relief pattern remains insoluble in the developer.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefits of U.S. Provisional Application 63 / 135,217, filed January 8, 2021, and U.S. Non-Provisional Application 17 / 455,753, filed November 19, 2021, which are hereby incorporated herein by reference in their entirety. Technical Field

[0003] The present invention generally relates to microfabrication, and in certain embodiments to the microfabrication of integrated circuits using self-aligned dual patterning. Background Technology

[0004] In materials processing methods (such as photolithography), creating a patterned layer typically involves applying a thin layer of radiation-sensitive material (such as photoresist) to the upper surface of a substrate. This radiation-sensitive material is then converted into a patterning mask in a lower layer that can be used to etch or transfer patterns onto the substrate. Patterning the radiation-sensitive material generally involves using, for example, a photolithography exposure system to expose the radiation-sensitive material from a radiation source through a mask (and associated optics).

[0005] This exposure creates a latent pattern within the radiation-sensitive material, which can then be developed. Development involves dissolving and removing a portion of the radiation-sensitive material to create an embossed pattern (morphological pattern). Depending on the photoresist tint and / or the type of developing solvent used, the removed material can be either an irradiated or unirradiated area of ​​the radiation-sensitive material. The embossed pattern can then be used as a mask layer defining the pattern.

[0006] The preparation and development of various films used for patterning may include thermal treatments (e.g., baking). For example, newly applied films may undergo post-application baking (PAB) to evaporate solvents and / or increase structural stiffness or etch resistance. Additionally, post-exposure baking (PEB) may be performed to set a given pattern to prevent further dissolution. Processing tools used for coating and developing substrates typically include one or more baking modules. Some photolithography processes involve coating a substrate with a thin film of bottom anti-reflective coating (BARC), followed by coating with a resist, and then exposing the substrate to a light pattern as a process step for forming a microchip. The resulting embossed pattern can then be used as a mask or template for additional processing, such as transferring the pattern to an underlying layer.

[0007] The minimum resolution achievable through a single photolithography exposure is, among other things, limited by the wavelength of light used (the so-called diffraction limit). The diffraction limit can be reduced using techniques such as immersion lithography. Multiple patterning processes, such as self-aligned double patterning (SADP), are increasingly being used to scale semiconductor features below the photolithographic limit. Multiple patterning processes can double the spacing (for each additional pattern) and thus facilitate feature sizes that are otherwise unattainable.

[0008] However, multiple patterning processes are often costly and complex. Furthermore, multiple patterning workflows may be incompatible with high-volume manufacturing. Additionally, many multiple patterning techniques require extra process steps, such as etching, deposition, development, and finishing, which also increases complexity and reduces throughput. Therefore, multiple patterning processes that reduce cost, complexity, and / or increase compatibility are desirable. Summary of the Invention

[0009] According to one embodiment of the present invention, a method of patterning a substrate includes depositing an outer coating layer in openings of an embossed pattern supported by the substrate. The embossed pattern includes a solubility modifier and a first removable protective monomer sensitive to the solubility modifier. The outer coating layer includes a second removable protective monomer sensitive to the solubility modifier. The embossed pattern has a first solubility threshold relative to a predetermined developer, while the outer coating layer has a second solubility threshold relative to the predetermined developer that is lower than the first solubility threshold. The method further includes activating the solubility modifier to at least reach the second solubility threshold of the outer coating layer without reaching the first solubility threshold of the embossed pattern; diffusing the solubility modifier a predetermined distance from the structure of the embossed pattern into the outer coating layer to form soluble regions in the outer coating layer; and developing the substrate with the predetermined developer to remove these soluble regions of the outer coating layer. These soluble regions are soluble in the predetermined developer, while the embossed pattern remains insoluble in the predetermined developer.

[0010] According to another embodiment of the invention, a method of patterning a substrate includes depositing an outer coating layer in openings of an embossed pattern supported by the substrate. The embossed pattern includes a solubility modifier and a first removable protective monomer having a first activation energy. The outer coating layer includes a second removable protective monomer having a second activation energy. The first activation energy is higher than the second activation energy. The method further includes deprotecting the second removable protective monomer without deprotecting the first removable protective monomer to form soluble regions in the outer coating layer by activating the solubility modifier and diffusing the solubility modifier a predetermined distance from the structure of the embossed pattern into the outer coating layer, and developing the substrate with the predetermined developer to remove these soluble regions of the outer coating layer. These soluble regions are soluble in the predetermined developer, while the embossed pattern remains insoluble in the predetermined developer.

[0011] According to another embodiment of the present invention, a method of patterning a substrate includes forming an embossed pattern on a substrate from a photoresist layer by exposing a photoresist to photochemical radiation including a first wavelength to activate a first photoacid generator. The photoresist includes the first photoacid generator and a solubility modifier. The method further includes depositing a removable protective resin in openings of the embossed pattern, activating the solubility modifier, diffusing the solubility modifier a predetermined distance from the structure of the embossed pattern into the removable protective resin to form soluble regions in the removable protective resin by deprotecting the removable protective resin, and developing the substrate with a predetermined developer to remove these soluble regions of the removable protective resin. These soluble regions are soluble in the predetermined developer, while the embossed pattern remains insoluble in the predetermined developer. Attached Figure Description

[0012] To gain a more complete understanding of the invention and its advantages, reference will now be made to the following description, taken in conjunction with the accompanying drawings, in which:

[0013] Figure 1A-1F A conventional anti-spacer process flow, including a freezing step, is demonstrated. The conventional anti-spacer process occurs by dissolving the acid-sensitive overlayer from the photoresist core via acid diffusion;

[0014] Figures 2A-2E An example process flow for patterning a substrate to form anti-spacer features according to an embodiment of the present invention is shown, which avoids additional dissolution inhibition steps by activating a solubility modifier to at least reach the solubility threshold of the outer coating without reaching the solubility threshold of the embossed pattern.

[0015] Figures 3A-3D An example process flow for patterning a substrate to form anti-spacer features according to an embodiment of the present invention is shown, wherein a solubility modifier is used as a thermally induced acid generator when dissolving the outer coating material;

[0016] Figures 4A-4C An example process flow for patterning a substrate to form anti-spacer features according to an embodiment of the present invention is shown, wherein a solubility modifier is used as a photoacid generator when forming an embossed pattern, and a solubility modifier is used as a thermal acid generator when dissolving an outer coating material.

[0017] Figure 5A and 5B An example process flow for patterning a substrate to form anti-spacer features according to an embodiment of the present invention is shown, wherein a solubility modifier is used as a photoacid generator when dissolving the outer coating material;

[0018] Figure 6A and 6BAn example process flow for patterning a substrate to form anti-spacer features according to an embodiment of the present invention is shown, wherein a photodestructible quencher is used as a solubility modifier when dissolving the outer coating material;

[0019] Figure 7 Two qualitative graphs are shown according to embodiments of the present invention, wherein the left graph shows an example relationship between resist thickness and exposure dose and wherein the right graph shows an example relationship between solubility and deprotection;

[0020] Figure 8 Four qualitative diagrams illustrating potential scenarios according to embodiments of the invention are presented, taking into account the dissolution contrast and sensitivity of the photoresist and the outer coating.

[0021] Figure 9 An example method for patterning a substrate according to an embodiment of the present invention is shown;

[0022] Figure 10 An example method for patterning a substrate according to an embodiment of the present invention is shown; and

[0023] Figure 11 An example method for patterning a substrate according to an embodiment of the present invention is shown.

[0024] Unless otherwise indicated, corresponding numbers and symbols in different figures generally refer to corresponding parts. The figures are drawn to clearly illustrate relevant aspects of the embodiments, and these figures are not necessarily drawn to scale. The edges of features drawn in the figures do not necessarily indicate the termination of the feature's extent. Detailed Implementation

[0025] The manufacture and use of various embodiments are discussed in detail below. However, it should be understood that the various embodiments described herein can be applied to a wide variety of specific situations. The specific embodiments discussed are merely illustrative of specific ways of making and using the various embodiments and should not be construed as limiting the scope.

[0026] For clarity, the order of discussion of the different steps described herein has been presented. Generally, these steps can be performed in any suitable order. Furthermore, although each of the features, techniques, configurations, etc., described herein may be discussed in different places within this disclosure, it is intended that each concept can be implemented independently of or in combination with each other. Accordingly, the invention can be practiced and viewed in many different ways.

[0027] The continued miniaturization of microelectronics necessitates improved patterning resolution. One approach is spacer techniques that define sub-resolution line features through atomic layer deposition (ALD). However, a challenge with spacer techniques is that they can be complex and potentially expensive if opposite tonal features are desired, as they involve overcoating another material, chemical mechanical planarization (CMP), and reactive ion etching (RIE) to excavate the spacer material, leaving narrow trenches.

[0028] Anti-spacer technology is a self-aligned technique that uses the diffusion length of a reactive material to define a critical dimension (CD), thereby creating narrow trenches. To form narrow trenches (compared to, for example, narrow trenches), the reactive material can be spatially controlled via exposure through a mask. The reactive material can be uniformly controlled on the wafer through the decomposition of a thermally induced acid generator via a baking process. Anti-spacer technology enables the acquisition of narrow trench contact features at dimensions exceeding the capabilities of advanced lithography.

[0029] Some conventional anti-spacer processes are complex and inefficient due to the addition of several process steps. For example, a conventional anti-spacer process includes an additional outer coating step for patterning the structure, additional baking to diffuse the reactive material from the outer coating into the patterned structure, and an additional outer coating removal step. Then, after another outer coating step, there is a development step to form the anti-spacer structure.

[0030] Other conventional anti-spacer processes diffuse reactive materials from the patterned structure into the overcoat, but require a "freezing" step (i.e., a treatment to neutralize the potential solubility alteration of the layer containing acid-generating agents). The freezing step is necessary because the reactive materials are included in the patterned structure and therefore undesirably dissolve the patterned structure itself when future anti-spacer regions of the overcoat are dissolved. For example, a thermal freezing process can suppress the dissolution of deprotected photoresist cores in an aqueous developer, which is subsequently used to remove deprotected (or decrosslinked or otherwise soluble-altered) overcoats to reveal anti-spacer features.

[0031] However, freezing is not without its flaws, leading to reduced uniformity and increased CD (crystal density). Furthermore, the additional freezing step reduces throughput. Integrating thermal freezing functionality into photoresists presents a significant challenge due to the stringent requirements of high-volume manufacturing and the reactive environment of the polymer resins. Consequently, anti-spacer processes requiring fewer steps and compatible with high-volume manufacturing processes are desirable.

[0032] The techniques described herein include patterning a substrate without requiring a freezing step. That is, the described techniques are “freezing-free” methods for forming patterned substrates with sub-resolution spacer-resistant features. In various embodiments, the method of patterning the substrate includes forming an outer coating layer on an embossed pattern on the substrate. The embossed pattern includes a solubility modifier that is activated and diffused into the outer coating layer to form soluble regions within the outer coating layer while maintaining the insoluble nature of the embossed pattern. The soluble regions of the outer coating layer are then removed by developing the substrate.

[0033] Solubility modifiers can advantageously enable the formation of sub-resolution anti-spacer features without reaching a solubility threshold (e.g., deprotection threshold) of the embossed pattern relative to a predetermined developer (e.g., an aqueous developer). The solubility modifier can be an acid-generating agent. For example, the solubility modifier can be a photoacid generator (PAG), a thermoacid generator (TAG), a photodegradable quencher (PDQ), or other suitable solubility modifiers.

[0034] The technique described herein can advantageously pair the inherent solubility contrast of a selected overlay material and a selected embossing material (e.g., photoresist), allowing the solubility of the overlay to be altered to form a desired spacer structure, while the embossing remains completely or sufficiently insoluble in the developing solution (e.g., insoluble relative to the solubility of the overlay in a predetermined developer). The advantage of this method is that it provides a way to prevent the embossing from dissolving by avoiding any necessary additional steps (e.g., a freezing step).

[0035] The various embodiments described herein involve controlling the photoresist contrast and photosensitivity relative to an acid-sensitive overlay to enable efficient and easy formation of spacer features compatible with high-volume manufacturing processes. The embodiments described herein will be described in detail relative to conventional spacer processes that include a freezing step. Furthermore, photosensitivity and dissolution parameters suitable for successful development will be described.

[0036] Figure 1A-1F This demonstrates a conventional anti-spacer process flow that includes a freezing step. Conventional anti-spacer processes occur by dissolving the acid-sensitive outer coating from the photoresist core via acid diffusion. Conventional anti-spacer processes unfavorably lead to deprotection of the photoresist, to the extent that it dissolves along with the reacted outer coating. To prevent the deprotected photoresist from dissolving during development, additional components or functions must be included in the photoresist formulation to prevent dissolution, along with additional processing steps.

[0037] refer to Figure 1AThe conventional anti-spacer process 100 includes forming a structured photoresist pattern 101 from a photoresist layer on a substrate 110 using photolithography. The structured photoresist pattern 101 includes a photoresist mandrel 102 separated by patterned openings 105. An additional acid source 103 (separated from the PAG used to form the photoresist mandrel 102) is included in the photoresist. A process-compatible crosslinking agent 104 must also be included in the photoresist.

[0038] Now for reference Figure 1B Then, an acid-sensitive resin 106 is coated onto a substrate 110 having a photoresist core 102, which is cast in a solvent that will not mix with the underlying photoresist. Figure 1C As shown, the acid source 103 in the photoresist is then activated 108 (by irradiation or baking), and the substrate 110 is baked to allow the acid to diffuse 107 into the surrounding acid-sensitive resin 106, causing a solubility change reaction within the acid-sensitive resin 106.

[0039] The diffusion depth 109 in the acid-sensitive resin 106 defines the CD of the anti-spacer characteristic (i.e., the anti-spacer thickness). This is in Figure 1D This is illustrated by the soluble resin region 111, which is now soluble in the aqueous developer. However, the activation and diffusion of the acid source 103 also has the undesirable effect of dissolving the photoresist core 102, resulting in the dissolution of the photoresist core 112. That is, in the conventional anti-spacer process flow 100, the photoresist becomes deprotected, exceeding the development (i.e., solubility) threshold of the photoresist in the aqueous developer.

[0040] If substrate 110 is developed at this stage, the change in photoresist solubility will prevent the formation of spacer features because the soluble photoresist core 112 will be removed in the developer. To address this change in solubility in the photoresist, a thermal freezing process 113 is performed to initiate a chemical reaction in the photoresist with a process-compatible crosslinking agent 104. This chemical reaction forms crosslinking bonds 114, inhibiting the solubility of the photoresist in the aqueous developer to form an insoluble crosslinked photoresist core 115.

[0041] However, this hot-freezing process results in additional acid diffusion. This additional acid diffusion must be accounted for within the available process window to achieve the desired anti-spacer CD. Furthermore, the inherent function of the resin or the development of additives that inhibit dissolution requires the material to be thermally stable, non-reactive to strong acids, exhibit minimal absorption at the irradiation wavelength, and not interfere with the patterning ability of the photoresist. This makes the hot-freezing process 113 more prone to defects and is not a preferred patterning technique.

[0042] Now for reference Figure 1FOnce the acid has deprotected the acid-sensitive resin 106 to the desired depth / thickness (diffusion depth 109) and the photoresist core is inhibited from dissolving, the substrate 110 is then developed in an aqueous developer to remove the soluble resin regions 111 and form conventional spacers 116 between the insoluble crosslinked photoresist core 115 and the remaining insoluble resin structure 117. However, the additional thermal freezing process 113 for forming crosslinks 114 also has the undesirable effect of producing an increased and irregular spacer width (118, 119) relative to the diffusion depth 109.

[0043] The embodiments described below advantageously avoid the need for a dissolution inhibition step (e.g., a thermal freezing step) by selecting a combination of core material, outer coating material, and dissolution transfer agent sufficient to achieve dissolution contrast. For example, the outer coating material can be advantageously selected such that it achieves a sharp change in solubility at a level far below that required for the deprotection of the photoresist used to form the relief pattern on the core, thereby primarily protecting the photoresist and making it insoluble in the predetermined developer.

[0044] The embodiments provided below describe various methods for patterning substrates, and in particular, methods for forming anti-spacer features without additional dissolution inhibition steps. The embodiments are described below. Figures 2A-2E This describes a process flow for an embodiment used to pattern a substrate to form anti-spacer features. Using Figures 3A-3D Sections 4A-4C, 5A-5B, and 6A-6B describe four additional embodiment process flows. Using Figure 7 The qualitative plots in the text discuss changes in solubility, while using... Figure 8 Four potential scenarios for the process flow of the embodiments are described. (Using...) Figure 9-11 Three implementation methods are described.

[0045] Figures 2A-2E An example process flow for patterning a substrate to form anti-spacer features according to an embodiment of the present invention is shown, which avoids additional dissolution inhibition steps by activating a solubility modifier to at least reach the solubility threshold of the outer coating without reaching the solubility threshold of the embossed pattern.

[0046] refer to Figure 2AThe process flow 200 begins with an embossed pattern 220 on a substrate 210. The embossed pattern 220 may be formed on the substrate 210 as part of the process flow 200 or as part of a separate process, and serve as the starting point for the process flow 200. For example, an example process flow 200 may include forming the embossed pattern 220 using photolithography or other suitable patterning processes (e.g., using photolithography from a photoresist layer). In one embodiment, the embossed pattern 220 is formed on the substrate 210 from a photoresist layer using an immersion lithography process. As a specific example, the embossed pattern 220 may be formed using a 193nm immersion lithography process.

[0047] It should be noted that, for the sake of brevity and clarity, convention has been adopted herein and hereinafter in which the element [x10] attached to the pattern can be a related embodiment of the substrate in various embodiments. For example, unless otherwise stated, substrate 210 can be similar to substrate 110. Similar conventions have also been adopted for other elements, as clearly described by using similar terminology in conjunction with the three-digit numbering system described above.

[0048] The embossed pattern 220 includes structures 222 on a substrate 210 separated by openings 226. The structures 222 and openings 226 of the embossed pattern 220 can be arranged in any desired pattern, such as a uniform pattern of a mandrel or an irregular pattern including various shapes, sizes, and spacings. The material of the embossed pattern 220 includes a solubility modifier 224. At this stage of process flow 200, the solubility modifier 224 in the structure 222 has not yet been activated. Therefore, the structure 222 is insoluble relative to the intended developer.

[0049] The predetermined developer can be any suitable developer. In various embodiments, the predetermined developer is an aqueous developer, and in some embodiments it includes tetramethylammonium hydroxide (TMAH).

[0050] To facilitate solubility alteration in the outer coating 230, diffusion of small-molecule reactive substances generated by applying energy from the solubility modifier 224 can be used. The solubility modifier 224 can be an acid generator such as PAG and / or TAG, and can also be another compound used as an acid generator such as PDQ. However, any suitable compound capable of imparting a solubility alteration at a specified point in process flow 200 can be used as the solubility modifier 224. Several specific embodiments of the solubility modifier 224 are described below in other examples.

[0051] Now for reference Figure 2BAn outer cladding layer 230 is deposited on substrate 210 to at least partially fill the opening 226 between structures 222. In various embodiments, the outer cladding layer 230 fills the opening 226. In some embodiments, an optional cover layer 232 (an outer cladding material located above the top surface of structure 222) may be produced.

[0052] Now for reference Figure 2C The solubility modifier 224 is activated by applying an activation energy E to the embossed pattern 220 to generate an acid 242, which diffuses 244 a predetermined distance 246 from the structure 222 into the outer coating 230. The predetermined distance 246 (i.e., the diffusion depth) can be controlled by any combination of diffusion variables to achieve a desired diffusion depth related to the thickness of the dissolved outer coating 230. Possible variables that can be changed include, but are not limited to, acid molecular weight, acid concentration, baking temperature, baking time, alkali concentration, and polymer composition.

[0053] The desired CD can be adjusted by modifying the molecular weight of the reactive substance produced by solubility modifier 224, the molecular structure of the reactive substance, and the baking temperature and baking time. Furthermore, the CD can be controlled by the composition of the outer coating 230 into which the reactive substance diffuses. The polarity of the components within the outer coating 230 may affect the acid diffusivity, and the activation energy of the reactive substance-sensitive components in the outer coating 230 is an additional means of controlling the treatment.

[0054] The activation energy E can take any suitable form. For example, the activation energy E can be provided in the form of photochemical radiation, thermal energy, or a combination of both. Light (e.g., electromagnetic radiation) and heat (e.g., convection, conduction, or radiative heat) generate acids from PAG or TAG, respectively. To activate PAG, some areas or the entire substrate 210 (including all support layers) can be irradiated at the appropriate wavelength for activating PAG. TAG can be activated by baking the substrate 210 to a temperature sufficient to decompose TAG. However, the specific mechanism for activating the solubility modifier 224 depends on the chosen solubility modifier and may also include other mechanisms. Activation and diffusion can occur sequentially or simultaneously.

[0055] The activation and diffusion of the solubility modifier 224 results in a soluble region 250 adjacent to the structure 222 of the embossed pattern 220, which remains insoluble relative to a predetermined developer. The soluble region 250 has a predetermined width 247 proportional to a predetermined distance 246. Due to the solubility change caused by diffusion into the outer coating 230, the predetermined width 247 of the soluble region 250 can be equal to the predetermined distance 246 (as shown). However, in some cases, the solubility modifier 224 (e.g., generated acid) can diffuse into regions of the outer coating 230 (farthest from the structure 222) without reaching the solubility threshold of the outer coating 230. Therefore, in practice, the predetermined width 247 of the soluble region 250 is less than or equal to the predetermined distance 246.

[0056] Now for reference Figure 2E The substrate 210 supporting the embossed pattern 220 and the outer coating 230 having soluble regions 250 is developed using a predetermined developer to form an anti-spacer feature 260. Specifically, the result of the development process is the anti-spacer feature 260 defined by the structure 222 of the original embossed pattern 220 and the remaining outer coating structure 262 that did not dissolve during the activation and diffusion of the solubility modifier 224.

[0057] It is noteworthy and advantageous that, after activation and diffusion, no additional steps are required to prevent structure 222 from dissolving during development with a predetermined developer. In particular, with the embossed pattern material, outer coating material, and solubility modifier already selected to prevent solubility changes in this scheme, the soluble region 250 of the outer coating 230 can be removed without removing structure 222.

[0058] Furthermore, compared to the conventional anti-spacer process 100, the resulting anti-spacer feature 260 can advantageously have an anti-spacer width 248 that is substantially equal to the predetermined width 247. Additionally, preventing the dissolution of structure 222 and thereby avoiding crosslinking (or other dissolution-inhibiting process steps) can advantageously produce a uniform anti-spacer feature 260. Therefore, in addition to the effectiveness, compatibility, and simplicity provided by process 200, a smaller CD can be achieved.

[0059] The types of materials chosen for the structure 222 (e.g., photoresist), the outer coating 230 (e.g., resin), and the solubility modifier 224 (PAG, TAG, PDQ, etc.) of the embossed pattern 220 can influence the process flow 200. For example, choices can be made that maximize the selectivity between the deprotection rate of the embossed pattern material and the outer coating material. In one embodiment, the outer coating 230 includes a developable bottom antireflective coating (dBARC). dBARC can advantageously decrosslink in the presence of low acid concentrations (e.g., acid concentrations required to deprotect the embossed pattern material).

[0060] The activation energy of the deprotectable monomers within the embossed pattern 220 of the outer coating 230 can be high to allow for higher deprotection kinetics relative to the outer coating 230 of structure 222. In some embodiments, the embossed pattern 220 includes high activation energy leaving groups, such as methyladamantyl methacrylate (MAMA), isoadamantyl methacrylate (IAM), or tert-butyl acrylate (TBA).

[0061] The activation energy of the deprotectable monomers included in the outer coating material can influence the choice of embossed pattern material. For example, if the outer coating 230 includes deprotectable monomers with low activation energy, such as monomers with acetal functionality like 1-butoxyethyl methacrylate (BEMA) or monomers with low activation ester functionality like tert-butylcyclopentyl methacrylate (TBCPMA), the activation energy of the embossed pattern material can be lower than that of adamantyl methacrylate, as found with the leaving group of ethylcyclopropyl methacrylate (ECPMA).

[0062] The remaining monomers in the relief pattern can be used for line forming and etching pattern transfer specifications. Conventional monomers used for standard photolithographic patterning can be selected for this purpose. In some embodiments, the cladding 230 is transparent in a wavelength range (e.g., allowing photochemical radiation in that range to pass through the cladding). However, this is not a requirement for the cladding 230.

[0063] Figures 3A-3D An example process flow for patterning a substrate to form anti-spacer features according to an embodiment of the present invention is shown, wherein a solubility modifier is used as a TAG when dissolving the outer coating material. Figures 3A-3D The process flow can be other process flows or other process flows described herein (such as, for example) Figures 2A-2E The specific implementation methods for each stage of the process flow are described above. Components with similar markings may be as previously described.

[0064] refer to Figures 3A-3D The process flow 300 optionally includes forming an embossed pattern 320 on a substrate 310. To form the embossed pattern 320, a photoresist layer 327 supported by the substrate 310 is exposed to photochemical radiation 321. This exposure activates PAG 325, which is included in the photoresist layer 327 along with TAG 324 (a solubility modifier). PAG 325 is sensitive to wavelengths λ included in the spectrum of the photochemical radiation 321. The photoresist layer 327 is exposed to the photochemical radiation 321 through a photomask 323 (or is shielded by an opaque structure formed on the photoresist layer 327) to form a latent pattern within the photoresist layer 327.

[0065] An embossed pattern 320, including a structure 322 separated by openings 326, is formed by developing the substrate 310 to remove potential patterns. Figure 3B Alternatively, process flow 300 can begin with an already formed relief pattern 320. Structure 322 comprises both a TAG 324 that is not activated by photochemical radiation 321 and a PAG 325 that is shielded from photochemical radiation 321 by a photomask 323. As a result, at this stage of process flow 300, structure 322 is insoluble relative to a predetermined developer.

[0066] like Figure 3C As shown, by applying heat 340 at a predetermined temperature T to a substrate 310 including an outer coating 330 formed on an embossed pattern 320, TAG 324 is activated to generate acid 342, which diffuses 344 a predetermined distance 346. Notably, PAG 325 remains in structure 322 but is not activated by the applied heat 340. The diffusion process can also be partially or completely promoted using a separate heat application (e.g., baking using different parameters such as duration and / or temperature compared to the heat 340 applied to activate TAG 324).

[0067] Then, by developing the substrate 310 supporting the relief pattern 320 and the outer coating 330 with a predetermined developer, an anti-spacer feature 360 ​​having an anti-spacer width 348 is formed. Figure 3D Specifically, the result of the development process is an anti-spacer feature 260 defined by the structure 322 of the original relief pattern 320 and the remaining outer coating structure 362 that did not dissolve during the activation and diffusion of TAG 324. PAG 325 is not activated during the application of heat 340, and the activated TAG 324 is insufficient to dissolve the photoresist of structure 322, but sufficient to dissolve an appropriate amount of acid diffused into the area of ​​the outer coating 330. For example, the solubility threshold of the photoresist of the relief pattern 320 may be sufficiently higher than the solubility threshold of the outer coating 230. Additionally or alternatively, acid 342 may be a weak acid that does not significantly deprotect the photoresist.

[0068] Using TAG 324 as a secondary source of acid can be advantageously a significant variable for adjusting selectivity, as the strength of the resulting acid can be selected to allow it to react with the overlay 330 at a given process temperature T, while reacting with the photoresist of the embossed pattern 320 to a minimum.

[0069] As mentioned above, both PAG and TAG can be included in the formulation of the photoresist underlayer. In this specific example, PAG is intended to remove the protective photoresist during initial light exposure and subsequent baking and development steps to form an initial relief pattern on the substrate. TAG is then thermally activated at a temperature higher than the temperature of the post-exposure baking (PEB) of the relief pattern.

[0070] Figures 4A-4C An example process flow for patterning a substrate to form anti-spacer features according to an embodiment of the present invention is shown, wherein a solubility modifier is used as a PAG when forming an embossed pattern, and a solubility modifier is used as a TAG when dissolving the outer coating material. Figures 4A-4C The process flow can be other process flows or other process flows described herein (such as, for example) Figures 2A-2E The specific implementation methods for each stage of the process flow are described above. Components with similar markings may be as previously described.

[0071] refer to Figures 4A-4C The process flow is similar to 400. Figures 3A-3D The process flow 300, except that no additional TAG is required, is because the PAG 425 included in the photoresist layer 427 used to create the relief pattern 420 on the substrate 410 also acts as TAG 424 at higher temperatures.

[0072] Exposure to photochemical radiation 421 (including wavelength λ) through photomask 423 activates PAG 425 to form a latent pattern in photoresist layer 427. As previously described, an embossed pattern 420 comprising structure 422 separated by opening 426 is formed by developing substrate 410 to remove the latent pattern. Figure 4B Structure 422 includes PAG 425 (TAG 424), which is not activated by photochemical radiation 421 because it is shielded from photochemical radiation 421 by photomask 423. As a result, at this stage of process flow 400, structure 422 is insoluble relative to the predetermined developer.

[0073] like Figure 4C As shown, by applying heat 440 at a predetermined temperature T to a substrate 410 including an outer coating 430 formed on an embossed pattern 420, TAG 424 is activated to generate acid 442, which diffuses 444 a predetermined distance 446. Then, the anti-spacer feature is formed by developing the substrate 410 supporting the embossed pattern 420 and the outer coating 430 using a predetermined developer.

[0074] In this specific example, PAG 425 serves to remove the protective photoresist during the initial light exposure and subsequent baking and development steps to form an initial relief pattern on the substrate, but then subsequently acts as a TAG (TAG 424) at a temperature higher than the relief PEB.

[0075] Figure 5A and 5B An example process flow for patterning a substrate to form anti-spacer features according to an embodiment of the present invention is shown, wherein a solubility modifier is used as a PAG when dissolving the outer coating material. Figure 5A and 5B The process flow can be other process flows or other process flows described herein (such as, for example) Figures 2A-2E The specific implementation methods for each stage of the process flow are described above. Components with similar markings may be as previously described.

[0076] The first two process flows describe a solubility modifier, which acts as a TAG to form soluble regions in the outer coating. Alternatively, another PAG activated at a different wavelength than the PAG used to form the initial embossed pattern can be used. For example, the polymer in the outer coating can have a removable protecting monomer that is activated with a weaker acid than the removable protecting monomer in the photoresist of the embossed pattern. This composition can advantageously promote little or no change in the CD of the initial structure of the embossed pattern, while making the outer coating readily dissolvable. Examples of removable protecting monomers (solubility modifier groups) that react at lower temperatures or with weaker acids compared to the initial embossed pattern are low-activation-energy ester leaving groups (such as those mentioned above) and acetal leaving groups.

[0077] refer to Figure 5A The process flow 500 includes a photoresist layer 527 disposed on a substrate 510. Both the first PAG 525 and the second PAG 524 are included in the photoresist layer 527 exposed to photochemical radiation 521 including a first wavelength λ1 through a photomask 523. Figure 5B As shown, the outer coating 530 is then exposed to photochemical radiation 540 including a second wavelength λ2 (different from the first wavelength λ1), which activates the second PAG 524 but not the first PAG 525 retained in the embossed pattern structure 522. The outer coating 530 is transparent to the second wavelength λ2. Heat 541 (e.g., providing energy for diffusion) can also be applied to diffuse acid 542 generated from the second PAG 524 into the outer coating 530. The heat 541 can be applied before, during, and / or after the application of the photochemical radiation 540 including the second wavelength λ2.

[0078] Figure 6A and 6BAn example process flow for patterning a substrate to form anti-spacer features according to an embodiment of the present invention is shown, wherein PDQ is used as a solubility modifier when dissolving the outer coating material. Figure 6A and 6B The process flow can be other process flows or other process flows described herein (such as, for example) Figures 2A-2E The specific implementation methods for each stage of the process flow are described above. Components with similar markings may be as previously described.

[0079] refer to Figure 6A and 6B The process flow 600 is similar to Figures 3A-3D In process flow 300, in addition to the photoresist layer 627 used to create the relief pattern 620 on the substrate 610, an additional TAG, PDQ 624, is included, which acts as a quencher during the formation of the relief pattern 620. As previously described, the photoresist layer 627, including PAG 625 and PDQ 624, is exposed to photochemical radiation 621, including wavelength λ, through a photomask 623. Figure 6B As shown, heat 640 is applied to the outer coating 630, which activates and diffuses 644PDQ 624 to produce acid 642 strong enough to deprotect the outer coating 630.

[0080] To facilitate the activation of PDQ 624 without activating PAG 625 (e.g., still within the embossed pattern 620), a difference between the conditions sufficient to activate PDQ 624 and PAG 625 can be used. For example, PDQ 624 can produce a weak acid, while PAG 625 can produce a strong acid. If the stronger PAG 625 is activated, the desired selectivity may not be achieved. The difference between the activation conditions of PDQ 624 and PAG 625 is a wavelength difference in one embodiment and a thermal difference in another embodiment.

[0081] In various embodiments, PDQ 624 is camphor sulfonate PDQ. In the presence of a superacid in the embossed pattern, camphor sulfonate acts as a quencher due to its pKa difference with the superacid. Diffusion of camphor sulfonate into the outer coating 630 (e.g., containing acetal functionality) can promote reaction with the polymer to form a soluble material in the regions where it has diffused. Camphor sulfonate can also be deprotected at slightly elevated temperatures from low-activation-energy esters such as TBCPMA.

[0082] Figure 7 Two qualitative graphs are shown according to embodiments of the present invention, wherein the left graph shows an example relationship between resist thickness and exposure dose and the right graph shows an example relationship between solubility and deprotection.

[0083] Chemically amplified photoresists (CARs) undergo solubility changes upon exposure to light of specific wavelengths via acid-catalyzed deprotection of the polymer resin by the acid generated from the decomposition of PAG. A measure of high-performance photoresists is a large solubility-to-contrast ratio, typically represented by a curve of photoresist thickness versus exposure dose, also known as a contrast profile. In positive photoresists, any excess deprotection, once a specific threshold for polymer deprotection is reached, significantly and non-linearly increases the film's solubility in aqueous developers, such as... Figure 7 As shown.

[0084] The technique described in this article works by selecting or formulating an outer coating and photoresist such that the outer coating exceeds its deprotection threshold (solubility threshold) within the process window before the photoresist becomes deprotected.

[0085] Figure 8 Four qualitative diagrams illustrating potential scenarios according to embodiments of the invention are presented, taking into account the dissolution contrast and sensitivity of the photoresist and the overlay.

[0086] Figure (A) illustrates the ideal scenario, where the outer coating exhibits high dissolution contrast and a deprotection threshold (solubility threshold) much lower than that of the photoresist, allowing for complete dissolution of the outer coating before the photoresist's solubility is affected. Photoresists with high dissolution contrast provide a wider process margin.

[0087] Figure (B) shows a similar situation to Figure (A); however, the critical deprotection thresholds of the outer coating and the photoresist begin to overlap, preventing the reproducible dissolution of the deprotected outer coating while preserving the photoresist core. Variables, including but not limited to acid strength, developer concentration, polymer composition, baking temperature, and baking time, can be adjusted to increase the process window between the two removable protective films, making it possible to approach or achieve the ideal situation shown in Figure (A).

[0088] Figure (C) illustrates a scenario where the photoresist is more sensitive than the outer coating, leading to complete dissolution of the photoresist before the critical deprotection of the outer coating. This system would require a freezing step and functionality within the photoresist to prevent dissolution of the deprotection resin.

[0089] Figure (D) is an example of a system in which the outer coating exhibits low dissolution contrast and high sensitivity relative to the photoresist. This system can advantageously achieve reproducible sub-resolution anti-spacer features if two process windows are considered. In one process window, the dissolution rate of the deprotected outer coating relative to the protected outer coating is sufficient to remove the anti-spacer region while preserving the surrounding outer coating. In the second process window, the degree of acid deprotection required to dissolve the outer coating results in minimal dissolution of the photoresist, thus preserving the structure of the relief pattern after the anti-spacer dissolves.

[0090] Various compositions can be selected for the methods described herein. The outer coating composition can be a polymer resin, and the resin can be composed of various monomer types. Most monomers within the outer coating can be structurally similar to the photoresist, resulting in similar etch rates for both films.

[0091] The aspect of the coating layer defined relative to the solubility contrast of the photoresist is the composition of acid-sensitive monomers. To maximize selectivity, the ratio of activation energies between the resist and the coating layer, sufficient to withstand solubility-changing reactions, should be high. Accordingly, the photoresist can have high-activation-energy deprotectable monomers such as MAMA or TBA. The coating layer can then have low-activation-energy monomers such as acetals, ECPMA, or another low-activation-energy ester with functionality (e.g., even lower than ECPMA).

[0092] As those skilled in the art will understand, other chemical combinations may be chosen for use herein. The outer coating material in TMAH can have a low dissolution rate R. min This allows for the formation of soluble regions within the outer coating. To create unexposed film thickness loss within the outer coating, monomers with inherent TMAH solubility can be used. Examples of this include monomers containing one of the following: dihexafluoroethanol (DiHFA), methyl methacrylate (MAA), and phenol.

[0093] As mentioned above, to simplify the formulation of embossed pattern materials, it may be advantageous to incorporate very low activation energy deprotectable monomers such as acetals or low activation energy esters into the outer coating. This can advantageously allow the weak acid components used in the formation of the embossed pattern to diffuse into the outer coating and induce a solubility shift in regions activated by acid diffusion. Many PAGs also act as TAGs at higher temperatures when they reach their thermal decomposition. Therefore, in some formulations, additional TAGs are not required in the embossed pattern material.

[0094] Figure 9 An example method for patterning a substrate according to an embodiment of the present invention is shown. Figure 9 The method can be combined with other methods and performed using systems and devices as described herein. For example, Figure 9 The method can be with Figure 2A-8 Any combination of the embodiments. Although shown in logical order, Figure 9 The arrangement and numbering of the steps are not intended to be limiting. As will be apparent to those skilled in the art, Figure 9 The steps can be performed in any suitable order or simultaneously with each other.

[0095] refer to Figure 9The method 900 for patterning a substrate includes step 901 of depositing an outer coating layer in an opening of an embossed pattern supported by the substrate. The embossed pattern may include a solubility modifier and a first removable protective monomer sensitive to the solubility modifier. The outer coating layer may include a second removable protective monomer sensitive to the solubility modifier. The embossed pattern has a first solubility threshold relative to a predetermined developer, while the outer coating layer has a second solubility threshold relative to the predetermined developer. The second solubility threshold is lower than the first solubility threshold.

[0096] Step 902 includes activating a solubility modifier to at least reach a second solubility threshold for the outer coating, but without reaching a first solubility threshold for the embossed pattern. In step 903, the solubility modifier is diffused a predetermined distance from the structure of the embossed pattern into the outer coating to form a soluble region in the outer coating. The soluble region is soluble in a predetermined developer, while the embossed pattern remains insoluble in the predetermined developer. Steps 902 and 903 may be performed simultaneously, separately, or partially overlapping. In step 904, the substrate is developed with the predetermined developer to remove the soluble region of the outer coating.

[0097] Figure 10 An example method for patterning a substrate according to an embodiment of the present invention is shown. Figure 10 The method can be combined with other methods and performed using systems and devices as described herein. For example, Figure 10 The method can be with Figure 2A-8 Any combination of the embodiments. Furthermore, Figure 10 The method can be used with, for example Figure 9 The method combination. Although shown in logical order, Figure 10 The arrangement and numbering of the steps are not intended to be limiting. As will be apparent to those skilled in the art, Figure 10 The steps can be performed in any suitable order or simultaneously with each other.

[0098] refer to Figure 10 The method 1000 for patterning a substrate includes step 1001 of depositing an outer coating layer in an opening of an embossed pattern supported by the substrate. The embossed pattern includes a solubility modifier and a first removable protective monomer having a first activation energy, while the outer coating layer includes a second removable protective monomer having a second activation energy. The first activation energy is higher than the second activation energy.

[0099] In step 1002, without removing the first removable protecting monomer, the second removable protecting monomer is removed to form a soluble region in the outer coating layer by activating a solubility modifier and diffusing the solubility modifier a predetermined distance from the structure of the embossed pattern into the outer coating layer. The soluble region is soluble in a predetermined developer, while the embossed pattern remains insoluble in the predetermined developer. In step 1003, the substrate is then developed with the predetermined developer to remove the soluble region of the outer coating layer.

[0100] Figure 11 An example method for patterning a substrate according to an embodiment of the present invention is shown. Figure 11 The method can be combined with other methods and performed using systems and devices as described herein. For example, Figure 11 The method can be with Figure 2A-8 Any combination of the embodiments. Furthermore, Figure 11 The method can be used as an example Figure 9 and 10 Any combination of the methods. Although shown in logical order, Figure 11 The arrangement and numbering of the steps are not intended to be limiting. As will be apparent to those skilled in the art, Figure 11 The steps can be performed in any suitable order or simultaneously with each other.

[0101] refer to Figure 11 The method 1100 for patterning a substrate includes step 1101 of forming an embossed pattern on the substrate from a photoresist layer by exposing a photoresist to photochemical radiation including a first wavelength to activate a first photoacid generator. The photoresist includes a first photoacid generator and a solubility modifier. In step 1102, a removable protective resin is deposited in the openings of the embossed pattern.

[0102] In step 1103, the solubility modifier is activated. Step 1104 involves diffusing the solubility modifier a predetermined distance from the structure of the embossed pattern into the removable protective resin to form soluble regions in the removable protective resin by removing the protective resin. The soluble regions are soluble in a predetermined developer, while the embossed pattern remains insoluble in the predetermined developer. Steps 1103 and 1104 may be performed simultaneously, separately, or partially overlapping. In step 1105, the substrate is then developed with the predetermined developer to remove the soluble regions of the outer coating.

[0103] In the foregoing description, specific details, such as the particular geometry of the processing system and the description of the various components and processes used therein, have been set forth. However, it should be understood that the techniques described herein may be practiced in other embodiments departing from these specific details, and such details are for illustrative purposes and not for limitation. Embodiments disclosed herein have been described with reference to the accompanying drawings. Similarly, specific figures, materials, and configurations have been set forth for illustrative purposes to provide a thorough understanding.

[0104] Various techniques have been described as multiple discontinuous operations to aid in understanding the various embodiments. The order of description should not be construed as implying that these operations must be performed in sequence. In fact, these operations do not need to be performed in the presented order. The described operations may be performed in an order different from the order of the described embodiments. In additional embodiments, various additional operations may be performed and / or the described operations may be omitted.

[0105] As used herein, "substrate" or "target substrate" generally refers to the object being processed according to the invention. A substrate may include any material portion or structure of a device (particularly a semiconductor or other electronic device) and may be, for example, a base substrate structure (such as a semiconductor wafer, a photomask), or a layer on or overlaid with a base substrate structure (such as a thin film). Therefore, a substrate is not limited to any particular base structure, underlayer, or overlay, whether patterned or unpatterned, but is contemplated to include any such layer or base structure, and any combination of layers and / or base structures. This description may refer to specific types of substrates, but this is for illustrative purposes only.

[0106] Exemplary embodiments of the invention are summarized herein. Other embodiments may also be understood from the entire specification and the claims set forth herein.

[0107] Example 1. A method of patterning a substrate, the method comprising: depositing an outer coating in an opening of an embossed pattern supported by the substrate, the embossed pattern including a solubility modifier and a first removable protective monomer sensitive to the solubility modifier, the outer coating including a second removable protective monomer sensitive to the solubility modifier, wherein the embossed pattern includes a first solubility threshold relative to a predetermined developer and the outer coating includes a second solubility threshold relative to the predetermined developer below the first solubility threshold; activating the solubility modifier to at least reach the second solubility threshold of the outer coating without reaching the first solubility threshold of the embossed pattern; diffusing the solubility modifier from the structure of the embossed pattern a predetermined distance into the outer coating to form soluble regions in the outer coating, these soluble regions being soluble in the predetermined developer, while the embossed pattern remains insoluble in the predetermined developer; and developing the substrate with the predetermined developer to remove these soluble regions of the outer coating.

[0108] Example 2. The method as described in Example 1, wherein the solubility modifier is a thermogenic acid generator, and wherein activating the solubility modifier includes applying heat to the substrate to activate the solubility modifier.

[0109] Example 3. The method of Example 2, further comprising: forming the relief pattern on the substrate, the relief pattern further comprising a photoacid generator different from the solubility modifier, wherein forming the relief pattern comprises forming the relief pattern from the photoresist layer by exposing the photoresist layer to photochemical radiation to activate the photoacid generator.

[0110] Example 4. The method as described in Example 2, further comprising: forming the relief pattern on the substrate, wherein the solubility modifier is also a photoacid generator, wherein forming the relief pattern comprises forming the relief pattern from the photoresist layer by exposing the photoresist layer to photochemical radiation to activate the solubility modifier.

[0111] Example 5. The method as described in Example 1, wherein the solubility modifier is a first photoacid generator activated at a first wavelength, the embossed pattern further includes a second photoacid generator activated at a second wavelength different from the first wavelength, and activating the solubility modifier includes exposing the first photoacid generator to photochemical radiation including the first wavelength to activate the first photoacid generator.

[0112] Example 6. The method as described in one of Examples 1 and 2, wherein the solubility modifier comprises a photodestructible quencher.

[0113] Example 7. The method as described in Example 6, wherein the light-destructive quencher is camphor sulfonic acid.

[0114] Example 8. The method as described in any one of Examples 1 to 7, wherein the outer coating includes a developable bottom antireflective coating.

[0115] Example 9. The method as described in any one of Examples 1 to 8, wherein the first deprotectable monomer comprises methyl-adamantyl methacrylate, isoadamantyl methacrylate, or tert-butyl acrylate.

[0116] Example 10. The method as described in any one of Examples 1 to 9, wherein the second deprotectable monomer comprises acetal or ester functionality.

[0117] Example 11. The method as described in any one of Examples 1 to 10, wherein the predetermined developer comprises tetramethylammonium hydroxide.

[0118] Example 12. A method of patterning a substrate, the method comprising: depositing an outer coating layer in an opening of an embossed pattern supported by the substrate, the embossed pattern including a solubility modifier and a first removable protective monomer having a first activation energy, and the outer coating layer including a second removable protective monomer having a second activation energy, the first activation energy being higher than the second activation energy; deprotecting the second removable protective monomer without deprotecting the first removable protective monomer to form soluble regions in the outer coating layer by activating the solubility modifier and diffusing the solubility modifier a predetermined distance from the structure of the embossed pattern into the outer coating layer, the soluble regions being soluble in the predetermined developer, while the embossed pattern remains insoluble in the predetermined developer; and developing the substrate with the predetermined developer to remove the soluble regions of the outer coating layer.

[0119] Example 13. The method as described in Example 12, wherein the solubility modifier is a thermogenic acid generator, and wherein activating the solubility modifier comprises applying heat to the substrate to activate the solubility modifier.

[0120] Example 14. The method as described in Example 12, wherein the solubility modifier is a photoacid generator, and wherein activating the solubility modifier includes exposing the photoacid generator to photochemical radiation to activate the photoacid generator.

[0121] Example 15. The method as described in one of Examples 12 and 13, wherein the solubility modifier comprises a photodestructible quencher.

[0122] Example 16. A method of patterning a substrate, the method comprising: forming an embossed pattern on a substrate from a photoresist layer by exposing a photoresist to photochemical radiation including a first wavelength to activate a first photoacid generator, the photoresist including the first photoacid generator and a solubility modifier; depositing a removable protective resin in an opening of the embossed pattern; activating the solubility modifier; diffusing the solubility modifier from the structure of the embossed pattern a predetermined distance into the removable protective resin to form soluble regions in the removable protective resin by deprotecting the removable protective resin, the soluble regions being soluble in a predetermined developer, while the embossed pattern remains insoluble in the predetermined developer; and developing the substrate with the predetermined developer to remove the soluble regions of the removable protective resin.

[0123] Example 17. The method as described in Example 16, wherein the solubility modifier is a thermogenic acid generator, and wherein activating the solubility modifier comprises applying heat to the substrate to activate the solubility modifier.

[0124] Example 18. The method as described in Example 16, wherein the first photoacid generator is activated at the first wavelength, the solubility modifier is a second photoacid generator activated at the second wavelength, and activating the solubility modifier includes exposing the second photoacid generator to photochemical radiation including the second wavelength to activate the second photoacid generator.

[0125] Example 19. The method as described in one of Examples 16 and 17, wherein the solubility modifier comprises a photodestructible quencher.

[0126] Example 20. The method as described in any one of Examples 16 to 19, wherein the photoresist has a higher contrast relative to the predetermined developer than the removable protective resin.

[0127] Although the invention has been described with reference to illustrative embodiments, this description is not intended to be limiting. Various modifications and combinations thereof will be apparent to those skilled in the art from the specification, illustrative embodiments, and other embodiments of the invention. Therefore, the appended claims are intended to cover any such modifications or embodiments.

Claims

1. A method for patterning a substrate, the method comprising: An embossed pattern is formed on a substrate, the embossed pattern including a first photoacid generator, wherein forming the embossed pattern includes forming the embossed pattern from the photoresist layer by exposing the photoresist layer to photochemical radiation to activate the first photoacid generator. An outer coating is deposited in the opening of the embossed pattern supported by the substrate. The embossed pattern also includes a solubility modifier different from the first photoacid generator and a first removable protective monomer sensitive to the solubility modifier. The outer coating includes a second removable protective monomer sensitive to the solubility modifier. The embossed pattern includes a first solubility threshold relative to a predetermined developer, and the outer coating includes a second solubility threshold relative to the predetermined developer that is lower than the first solubility threshold. The solubility modifier is activated to at least reach the second solubility threshold of the outer coating, but without reaching the first solubility threshold of the embossed pattern; The solubility modifier is diffused a predetermined distance from the structure of the embossed pattern into the outer coating to form soluble regions in the outer coating that are soluble in the predetermined developer, while the embossed pattern remains insoluble in the predetermined developer; and The substrate is developed with the predetermined developer to remove these soluble areas of the outer coating.

2. The method as described in claim 1, wherein, The solubility modifier is a thermogenic acid generator, and activating the solubility modifier includes applying heat to the substrate to activate the solubility modifier.

3. The method of claim 1, wherein, The first photoacid generator is activated at the first wavelength. The solubility modifier is a second photoacid generator activated at a second wavelength different from the first wavelength, and Activating the solubility modifier involves exposing the second photoacid generator to photochemical radiation including the second wavelength to activate the second photoacid generator.

4. The method of claim 1, wherein, The solubility modifiers include photodestructible quenchers.

5. The method of claim 4, wherein, The light-destructive quencher is camphor sulfonate.

6. The method of claim 1, wherein, The outer coating includes a developable bottom anti-reflective coating.

7. The method of claim 1, wherein, The first deprotectable monomer includes methyl-adamantyl methacrylate, isoadamantyl methacrylate, or tert-butyl acrylate.

8. The method of claim 1, wherein, The second deprotectable monomer includes acetal functionality or ester functionality.

9. The method of claim 1, wherein, The pre-selected developer includes tetramethylammonium hydroxide.

10. A method for patterning a substrate, the method comprising: An embossed pattern is formed on a substrate, the embossed pattern including a first photoacid generator, wherein forming the embossed pattern includes forming the embossed pattern from the photoresist layer by exposing the photoresist layer to photochemical radiation to activate the first photoacid generator. An outer coating is deposited in the opening of the relief pattern supported by the substrate. The relief pattern also includes a solubility modifier different from the first photoacid generator and a first deprotectable monomer having a first activation energy. The outer coating includes a second deprotectable monomer having a second activation energy, wherein the first activation energy is higher than the second activation energy. Without removing the first removable protective monomer, the second removable protective monomer is deprotected to form soluble regions in the outer coating by activating the solubility modifier and diffusing the solubility modifier a predetermined distance from the structure of the embossed pattern into the outer coating. These soluble regions are soluble in a predetermined developer, while the embossed pattern remains insoluble in the predetermined developer. The substrate is developed with the predetermined developer to remove these soluble areas of the outer coating.

11. The method of claim 10, wherein, The solubility modifier is a thermogenic acid generator, and activating the solubility modifier includes applying heat to the substrate to activate the solubility modifier.

12. The method of claim 10, wherein, The solubility modifier is a second photoacid generator, and wherein activating the solubility modifier includes exposing the second photoacid generator to photochemical radiation to activate the second photoacid generator.

13. The method of claim 10, wherein, The solubility modifiers include photodestructible quenchers.

14. A method for patterning a substrate, the method comprising: An outer coating is deposited in an opening of an embossed pattern supported by a substrate, the embossed pattern including a solubility modifier and a first removable protective monomer sensitive to the solubility modifier, the outer coating including a second removable protective monomer sensitive to the solubility modifier, wherein the embossed pattern includes a first solubility threshold relative to a predetermined developer and the outer coating includes a second solubility threshold relative to the predetermined developer below the first solubility threshold. The solubility modifier is activated to at least reach the second solubility threshold of the outer coating without reaching the first solubility threshold of the embossed pattern; The solubility modifier diffuses a predetermined distance from the structure of the embossed pattern into the outer coating, thereby forming soluble regions in the outer coating that are soluble in the predetermined developer, while the embossed pattern remains insoluble in the predetermined developer; and The substrate is developed using the predetermined developer to remove these soluble areas of the outer coating, wherein This solubility modifier is a first photoacid generator activated at the first wavelength. The embossed pattern further includes a second photoacid generator activated at a second wavelength different from the first wavelength, and Activating the solubility modifier involves exposing the first photoacid generator to photochemical radiation containing the first wavelength to activate the first photoacid generator.

15. The method of claim 14, wherein the outer coating comprises a developable bottom antireflective coating.

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