Response layer for photolithographic film stack

Abstract

Embodiments described herein relate to a method for patterning a patterned stack, the method comprising forming a patterned stack over a substrate, wherein the patterned stack comprises a response layer and a resist layer over the response layer. In an embodiment, the response layer is deposited at a temperature less than 250 °C using a plasma enhanced chemical vapor deposition (PECVD) process. In an embodiment, the process further comprises forming openings in the resist layer and transferring a pattern of the openings into the response layer. In an embodiment, the response layer has a first line width roughness (LWR). In an embodiment, the method further comprises reflowing the response layer to form a reflowed response layer, wherein the reflowed response layer has a second LWR that is less than the first LWR.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Patent Application No. 19 / 019,209, filed January 13, 2025, which claims the benefit of U.S. Provisional Application No. 63 / 552,009, filed February 9, 2024, and U.S. Provisional Application No. 63 / 712,322, filed October 25, 2024, the entire contents of which are hereby incorporated herein by reference. Technical Field

[0003] The embodiments relate to the field of semiconductor manufacturing, and more specifically, to apparatus and methods for using a responsive layer in an extreme ultraviolet (EUV) patterned stack to achieve improved line width roughness (LWR) and line edge roughness (LER).

[0004] Related technical descriptions

[0005] Semiconductor devices are continuously scaling down to smaller feature sizes. Improvements to lithography systems are needed to keep pace with this shrinking feature size. For example, extreme ultraviolet (EUV) lithography has been used to print smaller features. Unfortunately, EUV resists do not absorb EUV radiation well. That is, the chemical structure within the EUV resist does not readily react in the presence of EUV radiation, failing to produce the necessary solubility switching. Therefore, a larger dose of EUV radiation is required to achieve the desired contrast in the resist layer.

[0006] Increasing the dose leads to increased exposure time. This reduces system throughput and increases the cost of EUV flatbed printing. Some trade-offs can be made to reduce the necessary dose. For example, a lower dose of EUV radiation can be used at the expense of lower line edge roughness (LER) and / or line width roughness (LWR). High LER and LWR negatively affect pattern transfer and may not be desirable for all patterning processes. Summary of the Invention

[0007] The embodiments described herein relate to a method for patterning a patterned stack, the method comprising forming a patterned stack over a substrate, wherein the patterned stack includes a responsive layer and a resist layer over the responsive layer. In one embodiment, the responsive layer is deposited at a temperature below 250°C using a plasma-enhanced chemical vapor deposition (PECVD) process. In one embodiment, the process further includes forming openings in the resist layer and transferring a pattern of the openings into the responsive layer. In one embodiment, the responsive layer has a first linewidth roughness (LWR). In one embodiment, the method further includes reflowing the responsive layer to form a reflow responsive layer, wherein the reflow responsive layer has a second LWR smaller than the first LWR.

[0008] The embodiments described herein relate to a method for patterning a patterned stack, the method comprising forming a patterned stack over a substrate, wherein the patterned stack includes a responsive layer and a resist layer over the responsive layer. In one embodiment, the responsive layer is deposited using a spin-coating process. This process may also include forming openings in the resist layer and transferring a pattern of the openings into the responsive layer, wherein the responsive layer has a first linewidth roughness (LWR). In one embodiment, the process may further include reflowing the responsive layer to form a reflow responsive layer, wherein the reflow responsive layer has a second LWR smaller than the first LWR. Attached Figure Description

[0009] Figure 1 This is a cross-sectional view of a substrate having a patterned resist layer according to one embodiment, the patterned resist layer including defective line edge roughness (LER) and defective line width roughness (LWR).

[0010] Figure 2 This is a graph of exposure dose relative to LER according to one embodiment, and it shows that higher exposure doses result in improved LER.

[0011] Figure 3A This is a cross-sectional diagram of a substrate with a patterned stack according to one embodiment, the patterned stack comprising a responsive layer beneath a resist.

[0012] Figure 3B This is a cross-sectional diagram of a substrate having a patterned stack according to one embodiment, the patterned stack including a responsive layer under a resist, wherein an underlayer is present between the responsive layer and the resist.

[0013] Figures 4A to 4E This is a cross-sectional diagram illustrating a process for patterning a substrate having a patterned stack, according to one embodiment, the patterned stack including a modifiable responsive layer.

[0014] Figures 5A to 5C This is a cross-sectional illustration of a process for patterning a substrate having a patterned stack, according to an additional embodiment, the patterned stack including a modifiable responsive layer.

[0015] Figure 6 This is a diagram of chemical substances that can be used to form a disulfide layer according to one embodiment, which can be used as a responsive layer.

[0016] Figure 7 This is a process flow diagram of a process for patterning a substrate having a patterned stack according to one embodiment, the patterned stack including a modifiable responsive layer that exhibits a reduced LER when exposed to a stimulus treatment.

[0017] Figure 8 A block diagram of an exemplary computer system that can be used in conjunction with a processing tool according to one embodiment is shown. Detailed Implementation

[0018] The embodiments described herein include apparatus and methods for using responsive layers in extreme ultraviolet (EUV) patterned stacks to achieve improved linewidth roughness (LWR) and line edge roughness (LER). In the following description, several specific details are set forth to provide a thorough understanding of the embodiments. It will be apparent to those skilled in the art that the embodiments can be practiced without such specific details. In other instances, well-known aspects have not been described in detail to avoid unnecessarily obscuring the embodiments. Furthermore, it will be understood that the various embodiments illustrated in the accompanying drawings are illustrative representations and are not necessarily drawn to scale.

[0019] This document describes various embodiments or aspects of this disclosure. In some embodiments, different embodiments are practiced separately. However, the embodiments are not limited to separately practiced embodiments. For example, two or more different embodiments may be combined together to be practiced as a single device, process, structure, or the like. In some cases, the various embodiments may be combined together in their entirety. In other cases, a portion of a first embodiment may be combined with portions of one or more different embodiments. For example, a portion of a first embodiment may be combined with a portion of a second embodiment, or a portion of a first embodiment may be combined with portions of a second embodiment and a portion of a third embodiment.

[0020] The embodiments illustrated and discussed in the accompanying drawings are provided for the purpose of explaining some of the basic principles of this disclosure. However, the scope of this disclosure covers all related, potential, and / or possible embodiments, even those different from the idealized and / or illustrative examples presented. This disclosure even covers embodiments incorporating and / or utilizing modern, future, and / or unknown components, devices, systems, etc., as alternatives to functionally equivalent, similar, and / or analogous components, devices, systems, etc., used herein for purposes of explanation, illustration, and example in the embodiments illustrated and / or discussed.

[0021] In EUV lithography, a resist that is chemically reactive to EUV radiation is deposited on a substrate. EUV resists may include metal oxide (e.g., tin oxide) materials or chemically amplified resist (CAR) systems. Once deposited, the resist is selectively exposed to EUV radiation using a mask and / or a master photomask. EUV radiation triggers a chemical reaction within the resist. This chemical reaction can cause a change in the solubility of the exposed areas of the resist. The exposed resist can sometimes be considered as having a latent image of the desired pattern. After exposure, a development process can be used to selectively remove the exposed areas relative to the unexposed areas, or vice versa (depending on whether the resist is a positive-tone or negative-tone resist).

[0022] Patterns formed within the resist can then be transferred to the underlying patterned stack. However, surface features of the pattern in the resist can also be transferred to the underlying layer. Thus, if the resist is not patterned using straight sidewalls (e.g., low LER or low LWR), undesirable topography of the sidewalls will be transferred to the underlying layer.

[0023] Typically, EUV offset printing systems suffer from low absorption of EUV radiation in the resist. This low absorption results in high LER and high LWR at the edges of the patterned resist. Figure 1 An example of an element 100 having a patterned resist layer 130 is shown. Figure 1 This is a cross-sectional view of a substrate 101 having a resist layer 130 over a substrate 101. The substrate 101 can be any type of substrate (e.g., a silicon wafer, or the like). Although the resist layer 130 is illustrated as being directly on the substrate 101, other embodiments may include one or more interposer layers between the substrate 101 and the resist layer 130. For example, a patterned stack similar to any patterned stack described in more detail below may be provided between the substrate 101 and the resist layer 130.

[0024] In one embodiment, the resist layer 130 may be an EUV resist material, such as a metal oxide-based material or CAR. Although EUV resists have been described in detail herein, it will be understood that other resist materials and photolithography schemes may also suffer from similar absorption problems. That is, the terms "resist layer" or "resist" may encompass any type of resist material, such as those compatible with EUV radiation, deep ultraviolet (DUV) radiation, or any other one or more wavelengths of electromagnetic radiation suitable for photolithography processes. In one embodiment, the resist layer 130 may have been exposed and developed using a process similar to that described in more detail above. Therefore, openings 131 (sometimes also referred to as trenches, holes, or patterns) may extend through the thickness of the resist layer 130. Openings 131 may have sidewalls 133. As shown, sidewalls 133 have non-linear and irregular profiles. That is, the LER of sidewalls 133 is relatively high. Similarly, LWR 135 (i.e., the width of the opening 131 across the variation in the thickness of the resist layer 130) is high. These characteristics can lead to poor pattern transfer in the underlying substrate 101.

[0025] LER and / or LWR can be improved by increasing the exposure dose during the EUV flatbed printing exposure process. However, increasing the dose requires a longer exposure duration. This can lead to lower throughput and / or higher costs in EUV flatbed printing processes. Figure 2 This is a graph illustrating the general relationship between exposure dose (x-axis) and LER (y-axis). A lower LER is associated with improved patterning performance. As shown, increasing the dose can provide an improvement (i.e., a reduction) in LER. In some implementations, the improvement can be significant. For example, when the dose is significantly increased, an LER of approximately 8 nm can be reduced to approximately 2 nm.

[0026] Ideally, reductions in LER and LWR are achieved without increasing the dosage. This allows for improved throughput without sacrificing patterning performance. Previous research has focused on improving the chemical properties of the resist layer to provide such results. However, the embodiments disclosed herein use a modifiable responsive layer beneath the resist to improve LER and LWR. The responsive layer is formed of a material capable of “reflowing” in response to a stimulus. Thus, the responsive layer can be patterned and has a first LER / LWR similar to that of the resist layer. A stimulus (e.g., thermal, electromagnetic radiation, or chemical stimulus) is then applied to the responsive layer to induce reflow, resulting in a second LER / LWR lower than the first LER / LWR.

[0027] As used herein, “reflow” can refer to several different processes. In one embodiment, reflow can refer to bringing the material above its glass transition temperature or melting point. In this state, the material can flow (similar to a fluid). In other embodiments, reflow can refer to chemical processes involving the crosslinking and / or rearrangement of chemical bonds within the material. Typically, a reflow-responsive layer allows for alteration of the material's surface morphology to reduce the surface energy of the response layer.

[0028] In one embodiment, the responsive layer may also provide the functionality of the underlying layer. For example, the responsive layer may be a source of secondary electron generation and / or the generation of free radicals or other chemicals that diffuse into the resist layer during exposure. Secondary electrons and chemicals can improve the patterning properties of the resist layer. In other embodiments, the responsive layer may be a different layer from the underlying layer. In this embodiment, both the underlying layer and the responsive layer can be tuned to best perform their specific purposes.

[0029] In one embodiment, the responsive layer disclosed herein may comprise a number of different material systems. Typically, the material system used for the responsive layer comprises a material that can undergo refluxing in response to a treated stimulus. In some embodiments, the responsive layer may be an organic material. For example, the responsive layer may comprise one or more of polymethyl methacrylate (PMMA), polystyrene (PS), Nylon 12, or polydimethylglutarimide (PMGI), parylene, or the like. More typically, the responsive layer may comprise a linear polymer having refluxing behavior or a polymer network having reversible chemistry (e.g., reversible crosslinking or supramolecular crosslinking). In other embodiments, the responsive layer may be an inorganic material. For example, the responsive layer may comprise one or more of tin, bismuth, indium, or selenium. More typically, the inorganic material may be a material that has refluxing behavior at low temperatures (e.g., low melting temperatures). Other embodiments comprise polymers having disulfide bonds. For example, in some embodiments, polyurethane having disulfide bonds may be used.

[0030] In one embodiment, the responsive layer can be deposited using various deposition processes. For example, in some embodiments, dry deposition processes such as chemical vapor deposition (CVD), plasma-enhanced CVD (PE-CVD), atomic layer deposition (ALD), plasma-enhanced ALD (PE-ALD), physical vapor deposition (PVD), or similar techniques can be used. Dry processes may also include molecular layer deposition (MLD) processes. In one embodiment, wet processes, such as spin coating, can be used to deposit the responsive layer.

[0031] See now Figure 3A The illustration shows a cross-sectional view of an element 300 according to one embodiment. In one embodiment, the element 300 may include a substrate 301. The substrate 301 may be a semiconductor substrate, such as a silicon wafer. However, other semiconductor materials, ceramics, glass, or the like may also be used for the substrate 301. The substrate 301 may also have dimensions other than those of a wafer.

[0032] In one embodiment, a patterned stack is provided over a substrate 301. In one embodiment, the patterned stack may include a carbon-containing layer 302. The carbon-containing layer 302 may be a spin-on-carbon (SOC) material. In one embodiment, a hard mold 303 may be provided over the carbon-containing layer 302. In one embodiment, the hard mold 303 may contain any suitable material, such as an organic hard mold, an inorganic hard mold, or the like. For example, the hard mold 303 may contain silicon, nitrogen, a metal element, oxygen, carbon, or any other suitable element for developing the hard mold 303.

[0033] In one embodiment, a responsive layer 310 is provided over the rigid mold 303. The responsive layer 310 may be a material capable of reflowing in response to a stimulus. For example, the stimulus may include thermal stimulation, electromagnetic radiation stimulation (e.g., light, UV light, etc.), or chemical stimulation. As will be described in more detail below, the responsive layer 310 may be patterned. The responsive layer 310 is then treated with a stimulus to reduce the LER and / or LWR of the patterned surface of the responsive layer 310.

[0034] In one embodiment, the responsive layer 310 may comprise an organic material. For example, the responsive layer 310 may comprise a linear polymer with recirculation behavior or a polymer network with reversible chemistry (e.g., reversible crosslinking or supramolecular crosslinking). For example, the responsive layer 310 may comprise one or more of PMMA, PS, Nylon 12, or PMGI. Such polymer materials may be deposited using spin coating, CVD processes (such as plasma-enhanced CVD (PECVD)), or ALD processes. However, other deposition processes may also be used in some embodiments.

[0035] In another embodiment, the responsive layer 310 may comprise an inorganic material. For example, the responsive layer 310 may comprise one or more of tin, bismuth, indium, or selenium. More typically, the inorganic material may be a material that exhibits recirculation behavior at low temperatures (e.g., low melting temperatures). The inorganic material may be deposited using PVD, CVD, or ALD processes. However, other deposition processes may also be used in some embodiments.

[0036] Other embodiments include a responsive layer 310 comprising a polymer having disulfide bonds. For example, in some embodiments, a polyurethane having disulfide bonds may be used. The use of disulfide bonds allows the responsive layer 310 to reflow in a controlled manner in response to a given stimulus (e.g., heat or light). Such disulfide-based polymers may be deposited using an MLD process. However, other deposition processes may also be used in some embodiments.

[0037] In another embodiment, the responsive layer 310 may comprise a polymer material having relatively long carbon chains and light crosslinking. In some cases, the responsive layer 310 may include high EUV-absorbing heteroatoms in the monomer to improve the response to EUV radiation. This embodiment may allow for a further reduction in the required dosage of the overlying resist layer 330. In some cases, such linear polymer chains may be deposited using one or more PECVD processes including low-power, low-temperature, and / or pulsed plasma. Such polymers may also be deposited using spin-coating processes. In some embodiments, the polymer may be a low-dielectric-constant dielectric polymer material. A more detailed description of such linear polymers is described herein.

[0038] In some implementations, the reflow of the responsive layer is performed at a low temperature compatible with the remainder of the patterned stack. For example, the resist layer 330 is often damaged at low temperatures (e.g., melting or reflow). Therefore, in some cases, reflow temperatures up to approximately 250°C can be provided. Stimulation options other than heat (e.g., chemical and light) can also be used to protect the remainder of the patterned stack from elevated temperatures.

[0039] exist Figure 3AIn the illustrated embodiment, the responsive layer 310 can also be used as an underlayer. That is, the responsive layer 310 can play an active role in the chemical transformation of the exposed areas of the resist layer 330 during lithographic printing exposure. For example, the responsive layer 310 can be a source of secondary electrons and / or chemicals or free radicals diffused into the resist layer 330. Such electrons and substances can improve the rate of chemical reactions within the resist layer 330 in order to reduce the necessary dosage, improve contrast, and / or otherwise improve patterning performance.

[0040] In one embodiment, a resist layer 330 is provided above the responsive layer 310. The resist layer 330 can be any suitable photosensitive material compatible with a given lithography process. An EUV resist layer 330 is described in detail herein. However, it will be appreciated that the resist layer 330 can also be a deep ultraviolet (DUV) resist layer 330, or a resist layer 330 compatible with electromagnetic radiation of any other one or more wavelengths. In a particular embodiment, the resist layer 330 may comprise a metal oxide material composition. For example, the resist layer 330 may comprise a tin oxide material system. In other embodiments, the resist layer 330 may comprise a CAR material system.

[0041] The resist layer 330 can be deposited over the responsive layer 310 using any suitable process. In one embodiment, the resist layer 330 is deposited using a spin-coating process. In other embodiments, the resist layer 330 is deposited using a dry deposition process, such as CVD, PECVD, ALD, PEALD, or similar. In a dry deposition process, the composition of the resist layer 330 can be varied across the thickness of the resist layer 330. For example, the bottom of the tunable resist layer 330 is used to achieve adhesion, and the remainder of the tunable resist layer 330 is used to achieve sensitivity to EUV radiation.

[0042] See now Figure 3B The illustration shows a cross-sectional view of element 300 according to an additional embodiment. In one embodiment, Figure 3B Component 300 in the middle can be with Figure 3A Similar to element 300, an underlayer 315 is added. The underlayer 315 may be provided between the responsive layer 310 and the resist layer 330. The underlayer 315 may comprise any suitable underlayer material composition. For example, the underlayer 315 may comprise one or more of silicon, carbon, oxygen, or hydrogen. In different embodiments, other elements may also be integrated into the underlayer 315. The underlayer 315 may be tuned to improve the patterning properties of the resist layer 330. For example, the chemical structure of the underlayer 315 may generate more secondary electrons, free radicals, and / or other chemicals that can diffuse into the resist layer 330 during EUV exposure.

[0043] Separating the bottom layer 315 from the response layer 310 allows for improved optimization of both layers. Since the response layer 310 no longer needs to participate in the exposure process, it can be designed for improved reflow performance. Improved reflow performance may include the ability to reflow with less stimulation (e.g., lower temperature, lower luminous flux, lower chemical concentration, etc.) and / or a greater reduction in LER and / or LWR.

[0044] See now Figures 4A to 4E The illustration shows a series of cross-sectional diagrams depicting a process for patterning a patterned stack with improved LER and / or LWR, according to one embodiment. In one embodiment, Figures 4A to 4E Component 400 in the middle has the same Figure 3A The patterned stack of elements 300 is similar to the patterned stack described herein. However, it will be understood that, according to various embodiments, similar processes can be used to pattern a stack similar to any of those described in more detail herein.

[0045] See now Figure 4A The illustration shows a cross-sectional view of an element 400 according to one embodiment. In one embodiment, the element 400 may include a substrate 401. The substrate 401 may be similar to the substrate 301 described in more detail above. Similarly, the carbon-containing layer 402 and the hard mold 403 may be similar to the carbon-containing layer 302 and the hard mold 303 described in more detail above.

[0046] In one embodiment, a responsive layer 410 is provided over a rigid mold 403. The responsive layer 410 may be similar to any of the responsive layers described in more detail herein. For example, the responsive layer 410 may be a stimulus-responsive material. That is, the application of a stimulus (e.g., heat, light, chemical substance) may cause the responsive layer 410 to reflow in order to reduce LER and / or LWR. Typically, the responsive layer 410 may be an organic material, an inorganic material, or a disulfide-based material. The responsive layer 410 may be deposited over the rigid mold 403 using a spin coating process or a dry deposition process (e.g., CVD, PE-CVD, ALD, PE-ALD, PVD, MLD, etc.).

[0047] In one embodiment, a resist layer 430 is provided over the responsive layer 410. The resist layer 430 may comprise an EUV resist material or the like. For example, the resist layer 430 may comprise a metal oxide resist or a CAR. The resist layer 430 may be applied using a dry deposition process or a spin coating process. The resist layer 430 may be similar to any of the resist layers described in more detail herein.

[0048] See now Figure 4BThe illustration shows a cross-sectional view of an element 400 after exposure and development processes have been performed, according to one embodiment. In one embodiment, a resist layer 430 is selectively exposed using EUV radiation (or other suitable electromagnetic radiation) by using a mask and / or a master photomask (not shown). The EUV radiation triggers a chemical reaction within the resist layer 430. The chemical reaction can cause a change in the solubility of the exposed areas of the resist layer 430 in order to form a latent image of the desired pattern.

[0049] In some embodiments, exposure to EUV radiation can also result in the formation of substances, chemicals, and / or compounds within the responsive layer 410. Such substances, chemicals, and / or compounds can diffuse into the overlying resist layer 430 to participate in chemical reactions that provide solubility alterations within the exposed areas of the resist layer 430. That is, the responsive layer 410 can provide functionality similar to common underlayers used for EUV lithography. As illustrated, this diffusion of substances from the responsive layer 410 to the resist layer 430 provides particularly beneficial results (e.g., providing improvements in dosage and size) when used with the MOR resist layer 430 and / or with the PECVD-deposited responsive layer 410. For example, EUV exposure to the responsive layer 410 can generate highly reactive radical anions that can extract protons from adjacent sites, thereby decomposing into CO2, methyl formate, and methanol. In one embodiment, the released chemicals can promote crosslinking of metal clusters (e.g., tin clusters) in the overlying MORE resist layer 430.

[0050] Following exposure, a development process (e.g., an etching process) can be used to selectively remove the exposed area relative to the unexposed area, or to selectively remove the unexposed area relative to the exposed area (depending on whether the resist is a positive-tone or negative-tone resist). As shown, the development process can result in the formation of an opening 431 through the resist layer 430. The opening 431 can be a hole, a trench, or any other desired pattern extending through the thickness of the resist layer 430.

[0051] In one embodiment, opening 431 may have sidewalls 433. As shown, sidewalls 433 may have relatively high LER and LWR. This is likely (at least in part) due to the use of low-dose exposure to the etchant layer 430. For example, the exposure dose may be approximately 30 mJ / cm². 2 Or lower, or approximately 15 mJ / cm 2 Or lower. However, any dosage can benefit from the implementation methods disclosed herein.

[0052] See now Figure 4CThe figure illustrates a cross-sectional view of element 400 after the pattern of opening 431 has been transferred into the underlying response layer 410, according to one embodiment. In one embodiment, the pattern can be transferred using an etching process. The etching process can be wet etching or dry etching. As shown, opening 431 continues into the response layer 410 and includes sidewalls 413. Similar to sidewalls 433, sidewalls 413 may have high LER and LWR. This is due to the pattern transfer from resist layer 430 to response layer 410.

[0053] See now Figure 4D The figure illustrates a cross-sectional view of an element after a stimulation treatment process according to one embodiment. As shown, a stimulus 440 is applied to the element 400. The stimulus 440 induces a reflow of the response layer 410. When in a reflow state, the response layer 410 is able to adjust its free surface (e.g., sidewall 414) to minimize surface energy. Thus, Figure 4C The high LER and LWR of the sidewall 413 in Figure 4D The reduced exposure dose can be achieved by using improved LER and LWR in the sidewalls 414 of the modified response layer 410 to provide improved patterning in the underlying layer without requiring a higher exposure dose. This reduces costs and improves throughput without sacrificing performance.

[0054] Stimulus 440 may include thermal stimulation. For example, stimulation 440 may be applied by a hot lamp in an annealing chamber or the like. A hot plate, a heated base, an electrostatic chuck (ESC), or the like may also be used to apply thermal energy to element 400. In some embodiments, a laser may also apply the necessary thermal energy. Due to the material exceeding its glass transition temperature or melting temperature, the thermal energy may allow the response layer 410 to reflow.

[0055] Stimulus 440 may also include electromagnetic radiation exposure (e.g., UV radiation, visible light, etc.). This stimulation 440 can be more controllable than other solutions. For example, a light source can be provided above element 400, and the light source can provide a desired dose of light to achieve the desired effect. Light exposure can allow reflow through increased material fluidity, changes in chemical structure (e.g., reversible crosslinking, supramolecular crosslinking, etc.).

[0056] Stimulus 440 may also include chemical stimulation 440. Chemical stimulation 440 can be applied by injecting a chemical reagent that triggers backflow behavior into the chamber. For example, a chamber suitable for CVD or ALD processes can be used to apply the chemical reagent of stimulation 440 to the response layer 410.

[0057] See now Figure 4EThe figure illustrates a cross-sectional view of element 400 after the resist layer 430 has been stripped, according to one embodiment. As shown, the responsive layer 410 is now the top layer and is patterned with opening 431. Due to the low LER and LWR of the sidewalls 414, the subsequent patterning transfer to the hard mold 403 and carbon-containing layer 402 will also result in low LER and LWR characteristics. The patterning of opening 431 can be transferred to the hard mold 403 and carbon-containing layer 402 using any suitable etching process. After the patterned stack is fully patterned, an etching process can be used to pattern the underlying substrate 401. The etching of substrate 401 can include dry etching processes, wet etching processes, or similar methods.

[0058] See now Figures 5A to 5C The illustration shows a series of cross-sectional views depicting a process for reflow response layer 510 to reduce LER and LWR according to one embodiment. In one embodiment, Figures 5A to 5C The process described in the text can be compared with Figures 4A to 4E The process described in the text is similar, except for the case when peeling off the resist layer.

[0059] See now Figure 5A The illustration shows a cross-sectional view of an element 500 according to one embodiment. In one embodiment, the element 500 may include a substrate 501. The substrate 501 may be similar to the substrate 301 described in more detail above. Similarly, the carbon-containing layer 502 and the hard mold 503 may be similar to the carbon-containing layer 302 and the hard mold 303 described in more detail above.

[0060] In one embodiment, a responsive layer 510 is provided over a rigid mold 503. The responsive layer 510 may be similar to any of the responsive layers described in more detail herein. For example, the responsive layer 510 may be a stimulus-responsive material. That is, the application of a stimulus (e.g., heat, light, chemical substance) may cause the responsive layer 510 to reflow in order to reduce LER and / or LWR. Typically, the responsive layer 510 may be an organic material, an inorganic material, or a disulfide-based material. The responsive layer 510 may be deposited over the rigid mold 503 using a spin coating process or a dry deposition process (e.g., CVD, PE-CVD, ALD, PE-ALD, PVD, MLD, etc.).

[0061] like Figure 5A As shown, the responsive layer 510 has been patterned to form an opening 531. The patterning process used to form the opening 531 is similar to that described above. Figures 4A to 4C The described processing operations are similar. As shown in the figure, opening 531 may have sidewalls 513, which have high LER and LWR. This is due to the overlying resist layer ( Figure 5A(Not shown in the figure) Low-dose exposure resulted in a resist layer with high LER and LWR sidewalls. However, the resist layer was peeled off, rather than left on top of the patterned response layer 510 during stimulation treatment. Peeling off the resist layer allows the stimulus to more easily access the response layer 510.

[0062] See now Figure 5B The figure illustrates a cross-sectional view of element 500 during stimulation 540 treatment according to one embodiment. As shown, stimulation 540 is applied to element 500. Stimulation 540 induces reflow in response layer 510. When in a reflow state, response layer 510 can adjust free surfaces (e.g., sidewalls 514 and top surface 517) to minimize surface energy. Thus, Figure 5A The high LER and LWR of the sidewall 513 in Figure 5B The reduced surface energy can be achieved by using improved LER and LWR on the sidewalls 514 of the modified response layer 510 to provide improved patterning in the underlying layer without requiring a higher exposure dose. This reduces cost and improves throughput without sacrificing performance. Additionally, the absence of a structure above the top surface 517 of the response layer 510 allows for the creation of a curved surface to reduce surface energy.

[0063] Stimulus 540 may include thermal stimulation. For example, stimulation 540 may be applied by a hot lamp in an annealing chamber or the like. A hot plate, a heated base, a heated ESC, or the like may also be used to apply thermal energy to element 500. In some embodiments, a laser may also apply the necessary thermal energy. Due to the material exceeding its glass transition temperature or melting temperature, the thermal energy may allow the response layer 510 to reflow.

[0064] Stimulus 540 may also include electromagnetic radiation exposure (e.g., UV radiation, visible light, etc.). This stimulation 540 can be more controllable than other solutions. For example, a light source can be provided above element 500, and the light source can provide a desired dose of light to achieve the desired effect. Light exposure can allow reflow through increased material fluidity, changes in chemical structure (e.g., reversible crosslinking, supramolecular crosslinking, etc.).

[0065] Stimulus 540 may also include chemical stimulation 540. Chemical stimulation 540 can be applied by injecting a chemical reagent that triggers backflow behavior into the chamber. For example, a chamber suitable for CVD or ALD processes can be used to apply the chemical reagent of stimulation 540 to the response layer 510.

[0066] See now Figure 5CThe illustration shows a cross-sectional view of element 500 after patterning has been transferred to the remainder of the patterned stack according to one embodiment. Due to the low LER and LWR of the sidewalls 514, subsequent patterning transfer to the hard mold 503 and carbon-containing layer 502 will also result in low LER and LWR characteristics. The pattern of opening 531 can be transferred to the hard mold 503 and carbon-containing layer 502 using any suitable etching process. After the patterned stack is fully patterned, an etching process can be used to pattern the underlying substrate 501. Etching of the substrate 501 may include dry etching processes, wet etching processes, or similar methods.

[0067] See now Figure 6 The diagram illustrates a chemical diagram of the formation of a disulfide-containing material according to one embodiment. As shown, a disulfide (1) is added to a co-reactant (2) and a crosslinking agent (3). In one embodiment, the co-reactant may contain a diisocyanate, and the crosslinking agent may contain a triol. However, it will be understood that other chemical structures that allow suitable disulfide bonds, which allow for reflow, may be used according to the embodiments described herein. In some embodiments, the disulfide structure may be integrated into an organic polymer, such as polyurethane or the like. In one embodiment, the disulfide-bonded material may be deposited using an MLD process, a CVD process, an ALD process, or the like.

[0068] See now Figure 7 The illustration shows a process flow diagram of process 760 for improving LER and / or LWR in a patterned stack according to one embodiment. In one embodiment, process 760 may begin with operation 761, which includes depositing a patterned stack over a substrate. In one embodiment, the patterned stack includes a responsive layer and a resist layer. For example, the patterned stack may be similar to any of the patterned stacks described in more detail herein. The responsive layer may be a material that can be reflowed after treatment with a stimulus (such as a thermal stimulus, light stimulus, or chemical stimulus). The responsive layer may be similar to any of the responsive layers described in more detail herein. The resist layer may also be similar to any of the resist layers described in more detail herein. For example, the resist layer may be an EUV resist material.

[0069] In one embodiment, the process can continue at operation 762, which includes forming a pattern in the resist layer. The pattern in the resist layer can be formed by exposing the resist layer to electromagnetic radiation that drives a chemical reaction within the resist layer. In one embodiment, the exposure can be considered a relatively low dose. For example, the exposure dose could be approximately 30 mJ / cm². 2 Or lower, or approximately 15 mJ / cm 2Or lower. However, any dosage can benefit from the embodiments disclosed herein. After a latent image is formed in the resist layer, the developing process can form openings, trenches, or the like through the resist layer.

[0070] In one embodiment, the process can continue at operation 763, which includes transferring a pattern into a responsive layer. In one embodiment, the responsive layer has a first LWR and / or a first LER. The first LWR and first LER can be relatively high due to the low dose of resist layer exposure.

[0071] In one embodiment, the process can continue at operation 764, which includes processing the response layer. In one embodiment, the processed response layer has a second LWR and / or a second LER smaller than a first LWR and / or a first LER. The processing can be the application of a stimulus that causes the response layer to reflow (e.g., a thermal stimulus, a light-based stimulus, or a chemical stimulus). The reflowed response layer rearranges its surface profile to minimize the surface energy of the response layer. This results in a more linear surface with smaller LWR and LER.

[0072] After reflowing the response layer to reduce LWR and LER, the pattern in the response layer can be transferred to the remainder of the patterned stack. The underlying substrate can then be patterned using a suitable etching process. In this way, highly accurate, precise, and repeatable patterning can be provided on components with low exposure dose using EUV lithography. This reduces the cost of lithography processes and improves throughput.

[0073] The embodiments described in more detail herein can be further enhanced by utilizing deposition techniques and precursor formulation chemicals to customize the polymer structure of the response layer. That is, any of the response layers described herein can utilize deposition techniques, chemicals, and / or treatments similar to those described below. In one embodiment, the response layer can be customized to improve the dose-to-size (DtS) exposure to the resist layer and / or to control the backflow behavior of the response layer. In some embodiments, the use of one or more of cryogenic, low-power settings, and / or pulses can result in an improved polymer network within the response layer. More generally, this can result in a lightly crosslinked polymer with long linear CH2 chains, which reduces DtS and improves LWR. This allows for improved release of H from the response layer that can diffuse into the overlying resist layer. * The solubility switching is enhanced by improving the metal ligand removal rate. The longer linear chains allow for refluxing at lower temperatures, thus allowing for a reduction in surface energy, which results in an improved LWR.

[0074] As described herein, the responsive layer can be deposited using a dry deposition process. In a particular embodiment, the dry deposition process can be a PECVD process. The PECVD process can use any suitable plasma source, such as capacitively coupled plasma (CCP), inductively coupled plasma (ICP), remote plasma sources, or the like. When using a PECVD process, low-power plasmas and low deposition temperatures (e.g., less than 300°C, less than 250°C, or less than 100°C) can be used. It has been shown that using such milder deposition conditions (e.g., using nuclear magnetic resonance (NMR) spectroscopy) increases the distance between crosslinks, as indicated by an increase in peaks with chemical shifts consistent with the -CH2- moiety. For example, the NMR spectrum of the responsive layer may show a higher molar fraction of the sp3 aliphatic moiety than that of the sp2 aliphatic moiety. Additionally, the plasma can be pulsed. The pulse can include on-time and off-time cycles of up to 1 second and up to 1 second, up to 5 seconds and up to 5 seconds, up to 10 seconds and up to 10 seconds, up to 30 seconds and up to 30 seconds, or any other duration. In some embodiments, the plasma on-time duration is equal to the plasma off-time duration for each cycle. In other embodiments, the plasma on-time duration differs from the plasma off-time duration. Pulsed plasma in the PECVD deposition process allows for better preservation of monomer structures to produce linear polymer architectures.

[0075] In some embodiments, the precursor formulations used to deposit the responsive layer using this deposition process may include one or more monomers comprising a carbon structure containing one or more of hydrogen bonds, metal-ligand interactions, van der Waals interactions, hydrophobic effects, and / or dynamic covalent bonds (e.g., disulfides, oximes, imines, Michael adducts, or Diels-Alders). Suitable monomers may include one or more of the following: N-[3-(dimethylamino)propyl]methacrylamide, 1-vinyl-2-pyrrolidone, isoborneol methacrylate, norbornene, cyclohexyl methacrylate, styrene, vinylphenol, vinylpyridine, vinylimidazole, (2-methylpropenyl)benzene, norbornene carboxylic acid, propylene, acetylene, octene, cyclooctene, cyclooctadiene, cycloolefins, cis-3-hexen-1-ol, its isomers, or any combination thereof. In some embodiments, in addition to the monomers in the precursor formulation, the precursor formulation may further contain a polymer inhibitor to enable delivery of the monomers to the chamber where polymerization occurs (e.g., a PECVD chamber) while preventing polymerization in the delivery container (e.g., an ampoule). That is, in some embodiments, the precursor formulation may contain a monomer mixture and an inhibitor. In one embodiment, the polymer inhibitor may be approximately 1.0% by weight of the precursor formulation.

[0076] In one embodiment, a precursor formulation having the desired monomer is used to generate the polymeric material when deposited above a substrate within the chamber. In some embodiments, the polymeric material is linear. However, embodiments may also include polymeric structures such as branched polymers, chain polymers, comb polymers, hyperbranched polymers, crosslinked polymers, dendritic polymers, block copolymers, star polymers, brush polymers, AB2 star polymers, and palm AB polymers. n Polymers, H-shaped B2AB2 polymers, dumbbell-shaped polymers, cyclic block polymers, star-shaped block AB polymers n Polymer, coil-cycle-coil polymer, star A n B n Polymers, combinations of any polymer structural species, or the like. In some embodiments, a free radical initiator (e.g., Ar, He, NH3, H2, or the like) may also flow into the chamber along with the precursor formulation to preserve the monomer structure during deposition and minimize the reaction of the polymer chains after termination.

[0077] Besides PECVD deposition, spin coating can also be used to form responsive layers with linear chains and low crosslinking. For example, polymer materials can be synthesized and formulated into liquids. The liquid can then be applied to a substrate using spin coating. In some instances, the formulated polymer is dissolved using one or more organic solvents containing propylene glycol methyl ether acetate (PGMEA), 4-methyl-2-pentanol, anisole, or the like. In some embodiments, the formulation may also include surfactants to reduce the surface tension of the solvent / polymer mixture. Reducing surface tension allows for the preparation of thin coatings (e.g., approximately 100 nm or less). In some embodiments, the formulation may also include adhesion promoters to enhance the adhesion between the responsive layer and the substrate. In the case of spin-coated films, a baking process can be used after deposition to remove residual solvents and / or allow the responsive layer to be activated through mild crosslinking or reaction with other substances.

[0078] See now Figure 8 The diagram illustrates an exemplary computer system 800 of a processing tool according to one embodiment. In this embodiment, the computer system 800 is coupled to and controls processing within the processing tool. The computer system 800 may be connected (e.g., networked) to other machines in a local area network (LAN), an intranet network, an extranet network, or the Internet. The computer system 800 may operate within the capacity of a server or client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The computer system 800 may be a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a cellular phone, a network device, a server, a network router, a switch, or a bridge, or any machine capable of executing a set of instructions (continuously or otherwise) that specifies actions to be taken by that machine. Furthermore, although only a single machine of computer system 800 is shown, the term "machine" should also be considered to include any set of machines (e.g., computers) that independently or jointly execute instruction sets (or multiple instruction sets) to perform any one or more methodologies described herein.

[0079] Computer system 800 may include a computer program product or software 822 having a non-transitory machine-readable medium on which instructions are stored, which can be used to program computer system 800 (or other electronic device) to perform a process according to an implementation. Machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, machine-readable (e.g., computer-readable) media include machine-readable (e.g., computer-readable) storage media (e.g., read-only memory (“ROM”), random access memory (“RAM”), disk storage media, optical storage media, flash memory devices, etc.), machine-readable (e.g., computer-readable) transmission media (electrical, optical, acoustic, or other forms of propagated signals (e.g., infrared signals, digital signals, etc.)), etc.

[0080] In one embodiment, the computer system 800 includes a system processor 802, main memory 804 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM), or Rambus DRAM (RDRAM), etc.), static memory 806 (e.g., flash memory, static random access memory (SRAM), etc.), and auxiliary memory 818 (e.g., a data storage device), which communicate with each other via a bus 830.

[0081] System processor 802 represents one or more general-purpose processing devices, such as a microsystem processor, a central processing unit, or the like. More specifically, the system processor may be a complex instruction set computing (CISC) microsystem processor, a reduced instruction set computing (RISC) microsystem processor, a very long instruction word (VLIW) microsystem processor, a system processor implementing other instruction sets, or a system processor implementing a combination of instruction sets. System processor 802 may also be one or more special-purpose processing devices, such as application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal system processors (DSPs), network system processors, or the like. System processor 802 is configured to execute processing logic 826 for performing the operations described herein.

[0082] The computer system 800 may further include a system network interface device 808 for communicating with other components or machines. The computer system 800 may also include a video display unit 810 (e.g., a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 812 (e.g., a keyboard), a cursor control device 814 (e.g., a mouse), and a signal generation device 816 (e.g., a speaker).

[0083] Auxiliary memory 818 may include machine-accessible storage medium 831 (or more specifically, computer-readable storage medium) storing one or more instruction sets (e.g., software 822) embodying any of the methodologies or functions described herein. Software 822 may also reside wholly or at least partially within main memory 804 and / or system processor 802 during its execution, via computer system 800, main memory 804, and system processor 802, which also constitute machine-readable storage media. Software 822 may further be transmitted or received over network 861 via system network interface device 808. In one embodiment, network interface device 808 may operate using RF coupling, optical coupling, acoustic coupling, or inductive coupling.

[0084] Although machine-accessible storage medium 831 is shown as a single medium in the exemplary embodiment, the term "machine-readable storage medium" should be considered to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) that store one or more instruction sets. The term "machine-readable storage medium" should also be considered to include any medium capable of storing or encoding instruction sets for execution by a machine and causing the machine to execute any one or more methodologies. The term "machine-readable storage medium" should therefore be considered to include, but is not limited to, solid-state memory, as well as optical and magnetic media.

[0085] Specific exemplary embodiments have been described in the foregoing specification. It is obvious that various modifications can be made without departing from the scope of the foregoing claims. Therefore, the specification and drawings are to be considered illustrative rather than restrictive.

Claims

1. A method for patterning patterned stacks, the method comprising: The patterned stack is formed on a substrate, wherein the patterned stack includes a responsive layer and a resist layer above the responsive layer, and wherein the responsive layer is deposited using a plasma-enhanced chemical vapor deposition (PECVD) process at a temperature below 250°C. An opening is formed in the resist layer; The pattern of the opening is transferred to the response layer, wherein the response layer has a first linewidth roughness (LWR); and The response layer is reflowed to form a reflow response layer, wherein the reflow response layer has a second LWR that is smaller than the first LWR.

2. The method of claim 1, wherein the PECVD process is a pulsed PECVD process.

3. The method of claim 1, wherein the precursor formulation for the PECVD process comprises a monomer, the monomer comprising one or more of hydrogen bonds, metal ligand interactions, van der Waals interactions, hydrophobic effects, and / or dynamic covalent bonds.

4. The method of claim 3, wherein the precursor formulation comprises one or more of the following: N-[3-(dimethylamino)propyl]methacrylamide, 1-vinyl-2-pyrrolidone, isoborneol methacrylate, norbornene, cyclohexyl methacrylate, styrene, vinylphenol, vinylpyridine, vinylimidazole, (2-methylpropenyl)benzene, norbornene carboxylic acid, propylene, acetylene, octene, cyclooctene, cyclooctadiene, cycloolefin, cis-3-hexen-1-ol, or isomers thereof.

5. The method of claim 3, wherein the precursor formulation further comprises a polymer inhibitor.

6. The method of claim 1, wherein the response layer comprises a substantially linear polymer architecture.

7. The method of claim 1, wherein the responsive layer comprises a low dielectric polymer.

8. The method of claim 1, wherein forming the opening in the resist layer comprises: The resist layer and a portion of the responsive layer are exposed to extreme ultraviolet (EUV) radiation, wherein the responsive layer responds to the EUV radiation to generate a reactive substance, and wherein the reactive substance diffuses into the resist layer and participates in a chemical reaction within the resist layer, the chemical reaction providing a solubility switch to the portion of the resist layer; and The resist layer is developed after the solubility in the portion of the resist layer is switched.

9. The method of claim 1, wherein the responsive layer comprises a polymer structure, said polymer structure being a branched polymer, chain polymer, comb polymer, hyperbranched polymer, crosslinked polymer, dendritic polymer, arborescent polymer, block copolymer, star polymer, brush polymer, AB2 star polymer, palm AB n Polymers, H-shaped B2AB2 polymers, dumbbell-shaped polymers, cyclic block polymers, star-shaped block AB polymers n Polymer, coil-cycle-coil polymer, star A n B n A polymer, or a combination of any of the polymer structures.

10. The method of claim 1, wherein a free radical initiator is used during the PECVD process.

11. A method for patterning patterned stacks, the method comprising: The patterned stack is formed on a substrate, wherein the patterned stack includes a responsive layer and a resist layer on the responsive layer, and wherein the responsive layer is deposited using a spin coating process; An opening is formed in the resist layer; The pattern of the opening is transferred into the response layer, wherein the response layer has a first linewidth roughness (LWR); as well as The response layer is reflowed to form a reflow response layer, wherein the reflow response layer has a second LWR that is smaller than the first LWR.

12. The method of claim 11, wherein the spin coating process comprises dispensing a liquid polymer formulation onto the substrate.

13. The method of claim 12, wherein the liquid polymer formulation comprises a dissolved polymer in an organic solvent.

14. The method of claim 13, wherein the organic solvent comprises one or more of propylene glycol methyl ether acetate (PGMEA), 4-methyl-2-pentanol, or anisole.

15. The method of claim 12, wherein the liquid polymer formulation comprises a surfactant.

16. The method of claim 12, wherein the liquid polymer formulation comprises an adhesion promoter.

17. The method of claim 11, wherein the responsive layer comprises one or more of the following: N-[3-(dimethylamino)propyl]methacrylamide, 1-vinyl-2-pyrrolidone, isoborneol methacrylate, norbornene, cyclohexyl methacrylate, styrene, vinylphenol, vinylpyridine, vinylimidazole, (2-methylpropenyl)benzene, norbornene carboxylic acid, propylene, acetylene, octene, cyclooctene, cyclooctadiene, cycloolefin, cis-3-hexen-1-ol, or isomers thereof.

18. The method of claim 11, wherein the response layer has a molar fraction of sp3 aliphatic portion that is higher than that of sp2 aliphatic portion.

19. The method of claim 11, wherein the spin coating process further comprises: baking the response layer.

20. The method of claim 11, wherein the resist layer is a metal oxide resist material.

Images