Method for manufacturing a layer structure having a target topological profile

Abstract

A method for manufacturing a layer structure having a target topological profile in a step having a side and a lateral face is provided, comprising the processes: (a) depositing a dielectric layer on a preselected area of a substrate under first deposition conditions, wherein the dielectric layer has a portion whose resistance to fluorine and / or chlorine radicals under first dry etching conditions is adjusted; and (b) exposing the dielectric layer obtained in process (a) to fluorine and / or chlorine radicals under first dry etching conditions, thereby removing at least a portion of the portion of the dielectric layer, thereby forming a layer structure having a target topological profile on the substrate.

Description

Technical Field

[0001] The present invention generally relates to a method for fabricating a layer structure consisting of a dielectric layer in a step formed on a substrate. Background Technology

[0002] For etching films composed of metal oxides, nitrides, or carbides, plasma etching is often used because the etching rate is typically high (10-100 nm / s), and the etching is usually anisotropic due to the presence of ions. The presence of ions leads to relatively poor etching selectivity between materials. On the other hand, wet etching is usually isotropic and often allows for increased etching selectivity, but it reduces wafer-to-wafer reproducibility and / or uniformity, as well as yield. In addition, wet etching generates a large amount of chemical waste and is therefore often accompanied by safety and environmental concerns, thus causing problems.

[0003] To achieve uniform etching with sufficient etch selectivity, radical-based etching can be effectively used. This offers the combined benefits of dry etching with good selectivity and wet etching with isotropic properties. However, for their practical application, further research will be needed on specific patterning schemes and specific etch selectivity when different materials are used in adjacent layers to produce desired structures with specific topological profiles. Although radical etching techniques are known in the art, such as those disclosed in US 9,064,815 and US 9,275,834, further improvements will be required, particularly for forming films with desired topological profiles.

[0004] In particular, the selective etching of SiN films using wet etching chemicals has been widely used in the manufacture of semiconductor devices. For example, in the structure of SiN / SiO2 stacked layers used to manufacture memory cells for 3D-NAND devices, the SiN film is selectively etched using a hot (>100°C) phosphoric acid solution containing water. However, the etching rate varies with several parameters such as chemical concentration, temperature, and immersion duration. Furthermore, because a drying process is required after the wet cleaning process, it is difficult to precisely control the etching rate at the nanoscale, and the process yield is relatively low. Moreover, wet etching chemical waste can sometimes be harmful to our health; therefore, for safety and environmental reasons, specialized solid wet cleaning baths are required.

[0005] On the other hand, dry etching using SF6 or NF3 plasma is known and commonly used for side residual topology contouring of SiN film coatings. Due to the presence of ions, dry etching is typically directional, which increases the etching rate on the ion-exposed surfaces (typically horizontal surfaces). The presence of ions often makes conformal etching or top residual etching difficult to achieve. Therefore, in some cases, wet etching is generally more commonly used than dry etching. See US 20170345674A1 (dry etching with NF3 / O2), US 20180204733A1 (dry etching with SF6), and US 20120289056A1 (wet etching with phosphoric acid).

[0006] Wet etching is typically performed as disclosed in US 9,754,779B1, in which a SiN film is deposited onto a patterned surface under controlled conditions, followed by wet etching with a dHF solution to provide a sidewall or top / bottom residual topological profile in the SiN film. This technique utilizes the wet etching properties of SiN films to chemicals, where the chemical resistance differs between the horizontal and vertical surface portions of the SiN film. However, in the disclosed methods, to leave a portion of the SiN film on the sidewalls of the patterned structure or on the top / bottom of the surface of the patterned structure, the deposition process and wet etching process, which are essentially different processes, must be performed in separate processing chambers, resulting in high cost, low throughput, large footprint, and other problems.

[0007] It should be noted that, as discussed above, any discussion of problems and solutions related to the relevant field has been included in this disclosure solely for the purpose of providing background for the invention and should not be construed as an admission that any or all of the discussions were known at the time of completion of the invention or filing of this application. Summary of the Invention

[0008] In view of the foregoing, some embodiments provide a method for fabricating a layer structure having a target topological profile in a step having sides and lateral faces, comprising the processes of: (a) depositing a dielectric layer on a pre-selected region of a substrate under first deposition conditions, wherein the dielectric layer has a portion whose resistance to fluorine and / or chlorine radicals is modulated under first dry etching conditions; and (b) exposing the dielectric layer obtained in process (a) to fluorine and / or chlorine radicals under first dry etching conditions, thereby removing at least a portion of the dielectric layer, thereby forming a layer structure having a target topological profile on the substrate. The target topological profile may typically be a side residual topological profile, a lateral face residual topological profile, or a conformal topological profile.

[0009] In some embodiments, the method further includes, prior to process (a), the following processes: (i) providing reference deposition conditions and reference dry etching conditions under which a layer structure having a reference topological profile will be formed in a step on the substrate by performing processes (a) and (b); (ii) after comparing the reference topological profile thus obtained with a target topological profile, changing at least one parameter of the reference deposition conditions and / or at least one parameter of the reference dry etching conditions in such a way as to form a layer structure in a step on the substrate having a topological profile more similar to the target topological profile than the reference topological profile; (iii) performing processes (a) and (b) under the changed deposition / dry etching conditions; and optionally (iv) repeating processes (ii) and (iii) until the topological profile thus obtained is substantially equivalent to the target topological profile. Performing processes (i) to (iv) is preferred and allows for efficient determination of the first deposition conditions and the first dry etching conditions to appropriately adjust the chemical resistance of the second dielectric layer relative to the chemical resistance of the first dielectric layer. However, since the principle of “etch selectivity” is known in the art (e.g., the etch selectivity of films in wet etching), performing processes (i) and (iv) is not essential for performing processes (a) and (b), and given this disclosure, and especially the guidance disclosed herein, those skilled in the art can determine the conditions and / or structures required to perform processes (a) and (b) as routine experimental matters without much burden.

[0010] In various embodiments, a first exemplary embodiment relates to a method in which a dielectric layer comprises a first dielectric layer deposited on a substrate and a second dielectric layer deposited on and in contact with the first dielectric layer, wherein the second dielectric layer has a tolerance to fluorine and / or chlorine radicals adjusted such that the etch selectivity of the second dielectric layer relative to the first dielectric layer is at least 5 (e.g., at least 10, 50, 100, 500, or 1,000), wherein the etch selectivity is defined as the ratio of the etch rate of the second dielectric layer to the etch rate of the first dielectric layer under first dry etch conditions.

[0011] In some embodiments of the method, the first dielectric layer is composed of an oxide film, while the second dielectric layer is composed of a silicon nitride film. In some embodiments of the method, the first and second dielectric layers are of the same type, wherein the main chemical bonds constituting the first and second dielectric layers are the same.

[0012] A second exemplary embodiment relates to a method in which a first portion of a dielectric layer deposited on a side surface and a second portion of a dielectric layer deposited on a side surface have different resistance to fluorine and / or chlorine radicals under a first dry etching condition, wherein the etch selectivity of one of the first and second portions (wherein either one has a lower etch rate than the other of the first and second portions under a first dry etching condition) is at least 1.5 (e.g., at least 1.7, 2.0, 2.5, or 3.0), wherein the etch selectivity of one of the first and second portions is defined as the ratio of the etch rate of one of the first and second portions to the etch rate of the other of the first and second portions under the first dry etching condition. In a first exemplary embodiment, the dielectric layer is composed of first and second dielectric layers with different dry etch selectivities, while in a second exemplary embodiment, the dielectric layer is composed of a first portion (side portion) and a second portion (side portion) with different dry etch selectivities. However, these embodiments can be implemented in any combination.

[0013] A third exemplary embodiment relates to a method in which a portion of a dielectric layer deposited on a side surface and a portion of a dielectric layer deposited on the side surface have different thicknesses. While the first and second exemplary embodiments utilize differences in etch selectivity to achieve a target topological profile of the final layer structure, the third exemplary embodiment can achieve the target topological profile of the final layer structure without requiring differences in etch selectivity. However, the third exemplary embodiment can be implemented in any combination with the first and / or second exemplary embodiments.

[0014] A fourth exemplary embodiment relates to a method in which processes (a) and (b) are performed in the same chamber. In some embodiments of the method, fluorine and / or chlorine radicals are fluorine radicals generated remotely or within the same chamber by fluorine- and nitrogen-containing gases and rare gases. This exemplary embodiment may be performed in combination with any one or more of the disclosed embodiments.

[0015] For the purpose of summarizing various aspects of the invention and the advantages achieved over related technologies, certain objects and advantages of the invention are described in this disclosure. It should be understood, of course, that not all such objects or advantages may be achieved according to any particular embodiment of the invention. Therefore, by way of example, those skilled in the art will recognize that the invention may be implemented or carried out in a manner that achieves or optimizes one or more advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

[0016] Other aspects, features, and advantages of the invention will become apparent from the following detailed description. Attached Figure Description

[0017] These and other features of the invention will now be described with reference to the accompanying drawings of preferred embodiments, which are intended to illustrate rather than limit the invention. The drawings have been greatly simplified for illustrative purposes and are not necessarily to scale.

[0018] This patent or application document contains at least one color drawing. The Patent Office will provide a copy of this patent or application publication with color drawings upon request and payment of the necessary fees.

[0019] Figure 1 The graph illustrates, for example, the relationship between the etching thickness of different SiN films and the NF3 remote plasma exposure time.

[0020] Figure 2 The graph illustrates, for example, the relationship between the etching thickness of different SiN films and the HF wet etching exposure time.

[0021] Figure 3 The graph, used as an example, compares the etching selectivity of different SiN films in NF3 remote plasma etching with the etching thickness of SiN:1 film (refer to the etching thickness of SiN:1 film).

[0022] Figure 4A The graph, used as an example to compare with the etching rate of SiN:1 film (referencing the etching rate of SiN:1 film), shows the relationship between the etching rate of different SiN films and the refractive index of different films during remote plasma etching by NF3.

[0023] Figure 4B The graph, used as an example to compare with the etching rate of SiN:1 film (refer to the etching rate of SiN:1 film), shows the relationship between the etching rate of different SiN films and the refractive index of different films during HF wet etching.

[0024] Figure 5 The Fourier transform infrared (FTIR) spectra (color) of different SiN films are shown as examples.

[0025] Figure 6 The graph illustrates, for example, the relationship between the etching rate of the SiN film and the size of its Si-N peak area.

[0026] Figure 7 A schematic simplified process sequence in the manufacture of 3DNAND using fluorine radicals is shown as an example ((a)→(b)→(c)→(d)→(e)→(f)).

[0027] Figure 8AAn illustrative simplified process sequence in the fabrication of 3DNAND using fluorine radicals on a “ladder” is shown as an example ((a)→(b)→(c)→(d)).

[0028] Figure 8B The use of examples is shown Figure 8A The final structure manufactured by the process sequence.

[0029] Figure 9 A schematic simplified process sequence in the formation of sidewall spacers or spacer-defined double patterning (SDDP) using fluorine radicals is shown as an example ((a)→(b)→(c)→(d)→(e)).

[0030] Figure 10 An illustrative simplified continuous process scheme combining deposition and etching in cluster tools without disrupting the vacuum is shown by way of example.

[0031] Figure 11A A schematic simplified configuration of a remote plasma processing device is shown as an example, in which a remote plasma source is integrated into the main processing chamber.

[0032] Figure 11B A schematic simplified configuration of a remote plasma processing device is shown by way of example, in which remote plasma is generated and fed into a reaction chamber.

[0033] Figure 12A A scanning electron microscope (SEM) image of a cross section of a silicon nitride film formed on a patterned structure after fluorine radical etching according to a top / bottom removal scheme is shown as an example.

[0034] Figure 12B A scanning electron microscope (SEM) image of a cross-section of a silicon nitride film formed on a patterned structure after fluorine radical etching according to a side removal scheme is shown as an example.

[0035] Figure 13 The graph illustrates, for example, the different etch thicknesses of oxide films when exposed to remote plasma.

[0036] Figure 14 A schematic simplified configuration of a plasma processing apparatus equipped with an RF plasma source for deposition and a MW plasma source for dry etching is shown as an example.

[0037] Figure 15 The process of using one apparatus for deposition and another apparatus for wet etching is illustrated by way of example.

[0038] Figure 16The process of performing deposition and dry etching using a single device is illustrated by way of example.

[0039] Figure 17 A schematic simplified configuration of a plasma processing apparatus equipped with an RF plasma source and a remote plasma source is shown by way of example.

[0040] Figure 18A Scanning transmission electron microscopy (STEM) images of cross-sections of silicon nitride films formed before (“AsDepo”) and after (“AfterDry Etch”) are shown as examples.

[0041] Figure 18B The table shows the methods used to form Figure 18A The deposition conditions and dry etching conditions of the layered structure shown are illustrated.

[0042] Figure 19 The graph illustrates, for example, the different etching thicknesses of TiO films when exposed to remote plasma.

[0043] Figure 20 The graph illustrates different film etching thicknesses as examples.

[0044] Figure 21A A scanning electron microscope (SEM) image of a cross section of a titanium oxide film formed on a patterned structure prior to fluorine radical etching to form a layered structure with a top / bottom residual topological profile is shown as an example.

[0045] Figure 21B A scanning electron microscope (SEM) image of a cross-section of a titanium dioxide film formed on a patterned structure after fluorine radical etching to form a layered structure with a top / bottom remaining topological profile is shown as an example. The term "top / bottom" refers to "top and / or bottom," where the topological profile associated with the top and bottom portions varies with the aspect ratio of the trench; for example, when the aspect ratio is high (e.g., 5 or higher), the resulting layered structure may have a topological profile remaining only at the top.

[0046] Figure 22A A scanning electron microscope (SEM) image of a cross section of a silicon oxide film formed on a patterned structure prior to fluorine radical etching to form a layered structure with a conformal topological profile is shown as an example.

[0047] Figure 22B A scanning electron microscope (SEM) image of a cross section of a titanium oxide film formed on a patterned structure after fluorine radical etching to form a layered structure with a conformal topological profile is shown as an example.

[0048] Figure 23An illustrative simplified continuous process scheme (a) combining deposition and etching in clustered tools without disrupting the vacuum is shown by way of example, and an illustrative simplified continuous process scheme (b) performing deposition and etching in the same reactor. Detailed Implementation

[0049] In this disclosure, SiN is a film characterized or identified as a silicon nitride film, which may contain other elements such as oxygen, carbon, hydrogen, etc., and unavoidable impurities to a degree that such elements do not substantially alter the properties of the silicon nitride film. The SiN film includes not only SiN films but also SiNC films, SiNO films, SiNCO films, etc., depending on the process formulation. These film names are abbreviations commonly accepted in the art and only indicate the film type (simply indicated by the main constituent elements), and are used in a non-stoichiometric manner unless otherwise described. In some embodiments, SiN has a dielectric constant of about 2 to 10, typically about 4 to 8. Similarly, SiO film is a film characterized or identified as a silicon oxide film, which may contain other elements such as nitrogen, carbon, hydrogen, etc., and unavoidable impurities to a degree that such elements do not substantially alter the properties of the silicon oxide film. The SiO film includes not only SiO films but also SiOC films, SiON films, SiOCN films, etc.

[0050] In this disclosure, "step" refers to any structure formed on a substrate having a top surface, sidewalls and a bottom surface, which may be arranged in series continuously in the height direction or may be a single step, and may form a groove, through hole or other recess.

[0051] In some embodiments, the trench has a width of 10 nm to 50 nm (typically 15 nm to 30 nm) (wherein when the trench has a length substantially the same as the width, it is referred to as a via / hole, and its diameter is 10 nm to 50 nm), a depth of 30 nm to 200 nm (typically 50 nm to 150 nm), and an aspect ratio of 3 to 20 (typically 3 to 10).

[0052] In this disclosure, "gas" may include vaporized solids and / or liquids and may consist of a single gas or a mixture of gases. In this disclosure, the process gas introduced into the reaction chamber via a spray head may comprise, consist of, or be substantially composed of, precursor gases and additive gases. Precursor gases and additive gases are typically introduced into the reaction space as a mixture or separately. Precursor gases may be introduced using a carrier gas such as a rare gas. Additive gases may comprise, consist of, or be substantially composed of, reactant gases and diluent gases such as rare gases. Reactant gases and diluent gases may be introduced into the reaction space as a mixture or separately. Precursors may comprise two or more precursors, and reactant gases may comprise two or more reactant gases. Precursors are gases chemically adsorbed onto the substrate and typically contain metalloid or metallic elements constituting the main structure of the dielectric film matrix, and the reactant gases used for deposition are gases that react with the chemically adsorbed precursors on the substrate when the gas is excited to fix atomic layers or monolayers onto the substrate. "Chemical adsorption" refers to chemically saturated adsorption. Non-process gases, i.e., gases introduced without passing through a spray nozzle, can be used to seal the reaction space, for example, sealing gases such as rare gases. In some embodiments, "membrane" refers to a substantially non-porous layer that extends continuously in a direction perpendicular to the thickness direction to cover the entire target or related surface, or simply refers to a layer covering the target or related surface. In some embodiments, "layer" refers to a structure formed on a surface having a certain thickness, or a synonym for membrane or non-membrane structure. A membrane or layer may consist of discrete individual membranes or layers having certain characteristics or may consist of multiple membranes or layers, and the boundaries between adjacent membranes or layers may be transparent or opaque, and may be established based on physical, chemical and / or any other characteristics, forming process or sequence and / or the function or purpose of adjacent membranes or layers.

[0053] In this disclosure, "annealing" refers to the process of treating a material to its stable form, such as replacing terminal groups (e.g., alcohol groups and hydroxyl groups) present in the components with more stable groups (e.g., Si-Me groups) and / or forming more stable forms (e.g., Si-O bonds), which typically causes densification of the film.

[0054] Furthermore, in this disclosure, unless otherwise specified, the articles “a” or “an” refer to a species or a genus comprising multiple species. In some embodiments, the terms “constituting of” and “having” independently mean “generally or broadly comprising,” “comprising,” “substantially consisting of,” or “constituting of.” Additionally, in some embodiments of this disclosure, any defined meaning does not necessarily exclude the common and conventional meaning.

[0055] Furthermore, in this disclosure, since the working range can be determined based on routine work, any two numbers of a variable can constitute the working range of the variable, and any indicated range can include or exclude endpoints. Additionally, any indicated variable value (whether or not it is indicated by "about") can refer to an exact value or an approximate value and include equivalent values, and in some embodiments may refer to the mean, median, representative value, multi-value, etc.

[0056] In this disclosure, when conditions and / or structures are not specified, those skilled in the art can readily provide such conditions and / or structures through conventional experiments based on this disclosure. In all disclosed embodiments, any element used in one embodiment may be replaced by any equivalent element for the intended purpose, including those elements expressly, necessarily, or inherently disclosed herein. Furthermore, the invention is equally applicable to apparatuses and methods.

[0057] The embodiments will be described with reference to preferred embodiments. However, the present invention is not limited to the preferred embodiments described.

[0058] Some embodiments involve conformal etching, or producing top or side residual structures, by using fluorine radical dry etching of different metal-containing materials. Differences in etching selectivity between different metal compounds are present and vary with substrate temperature and the volatility of the resulting reaction products. Therefore, etching selectivity can be tuned by appropriately selecting the substrate temperature and reaction chemistry. In this disclosure, depending on the context, the term "metal" can include metalloid elements such as silicon. Additionally, in this disclosure, in the above context, the term "material" refers to the elements, components, or substances constituting the film, wherein different materials can include materials with different elements, materials with the same elements but different compositions, and materials with the same elements and compositions but different physical and / or chemical properties.

[0059] The remaining structure on the top and / or sides can be produced by (1) changing the deposition conditions of the material subsequently subjected to dry etching. In some embodiments, achievable etching rates are in the range of 0.1-1 nm / s, thereby allowing good control over the etching while maintaining good yield. (2) Changing the dry etching conditions can also be done in combination with (1) or as an alternative to (1). The proposed dry etching process flow also allows both deposition and etching to be performed in the same chamber or in the same cluster tool (having multiple chambers) to produce the remaining patterned film on the sides or top / bottom. This increases yield and avoids the problems associated with surface contamination due to exposure to air.

[0060] Because etch selectivity varies with the properties of the deposited material, the actual selectivity differences between different metal compounds and / or materials of different qualities (including those of the same type in element and / or composition) may manifest differently in dry and wet etching processes, but this selectivity is also expected to be representative of wet etching. However, for dry etching processes, it is easier to control the etch rate and wafer-to-wafer uniformity.

[0061] Some embodiments involve conformal etching or producing top or side remnants by using highly selective dry etching of SiN films with fluorine radicals. This allows for the replacement of conventionally used wet etching steps with dry etching steps. For example, the dry etching rate of the SiN film can be determined based on its density. As in wet etching, differences in dry etching selectivity between SiN films with different film properties are required to produce top or side remnants. Therefore, by varying the density of the SiN film on vertical and horizontal surfaces, desired topographic profiles (side or top / bottom remnants, or a combination thereof) can be obtained. In dry etching processes including those using conventional methods, oxides (SiO2, TiO2, and ZrO2) can also exhibit such high etching selectivity.

[0062] Furthermore, the proposed dry etching process allows for both SiN deposition and etching to be performed in the same chamber or in the same cluster of tools with multiple chambers, thereby increasing yield and avoiding problems associated with surface oxide formation due to air exposure. Additionally, the etching rate and wafer-to-wafer uniformity may be easier to control in dry etching processes than in wet etching processes.

[0063] Additionally, some embodiments involve performing deposition and dry etching processes in a single chamber or reactor to address at least one of the problems discussed in this disclosure. Typically, such a method includes: (1) depositing an insulating film on a patterned structure of a substrate in a reaction chamber by plasma-enhanced chemical vapor deposition (PECVD) or plasma-enhanced atomic layer deposition (PEALD), wherein a portion of the film deposited on a horizontal surface has different chemical resistance than a portion of the film deposited on a vertical surface (in this disclosure, "vertical" and "horizontal" or any similar terms are used as relative terms and are not intended to be limited to an exact direction of gravity and an exact direction orthogonal thereto, but they respectively refer to any general direction substantially parallel to the direction of anisotropic ion bombardment or the direction of film thickness, and any general direction substantially orthogonal thereto); and then (2) exposing the film deposited in process (1) to a remote plasma and performing isotropic dry etching in the same reaction chamber as in step (1) using a remote plasma system to remove a portion of the film (the portion of the non-target film remaining), thereby leaving a portion of the film substantially only on the sidewalls of the patterned structure or only on the top / bottom surface of the patterned structure.

[0064] In some aspects of the disclosed embodiments, the target topological profile of the final layer structure can be achieved by utilizing the difference in etch selectivity between the first and second dielectric layers and by controlling the directionality of the etch. In other aspects of the disclosed embodiments, the target topological profile of the final layer structure can be achieved by utilizing the difference in in-plane etch selectivity of the dielectric layers.

[0065] In some embodiments, by way of example only, the desired target topology profiles shown in Table 1 can be achieved by manipulating processes (a) and (b) as shown in Table 1 below, respectively, by controlling the directionality of deposition and, consequently, the directionality of etching. As shown in Table 1, in some embodiments, different operating schemes or combinations of processes (a) and (b) can result in the same or similar final topology profile types (side-dominant, conformal, or top / bottom-dominant, but the actual profiles may differ), wherein there are multiple ways (combinations) to achieve the same or similar results regarding the topology profile of the final layer structure. In Table 1, “T”, “B”, and “S” refer to “top”, “bottom”, and “side”, respectively, and “Figure #” indicates the figure number of the final layer structure formed using the corresponding scheme. In some embodiments, the term “conformal” refers to high conformal conformity, such as exceeding approximately 70% to 130% (e.g., 80% to 120%, 90% to 110%, most typically approximately 100%). In some embodiments, the term "dominant" refers to a non-conformal, substantial difference or a material difference for an intended purpose, such as a dominance of at least 40%, 50%, 100%, 200%, 500%, 1000%, or any range thereof. Additionally, in some embodiments, the term "residual" refers to the meaning of "dominant." In some embodiments, the term "low quality" refers to lower chemical resistance, such as a higher dry etching rate or lower density relative to a reference quality. In this disclosure, any number defining a numerical range is, for example, a representative number, an average number, a randomly selected number, a median, a conventionally or generally defined number, or any number equivalent to it depending on the context.

[0066] Table 1

[0067]

[0068] As discussed above, some embodiments provide a method for fabricating a layer structure with a target topological profile in a step having sides and lateral faces, comprising processes including: (a) depositing a dielectric layer on a pre-selected region of a substrate under first deposition conditions, wherein the dielectric layer has a portion whose resistance to fluorine and / or chlorine radicals is modulated under first dry etching conditions; and (b) exposing the dielectric layer obtained in process (a) to fluorine and / or chlorine radicals under first dry etching conditions, thereby removing at least a portion of the dielectric layer, thereby forming a layer structure with a target topological profile on the substrate. In this disclosure, the “chemical resistance” of a film can be evaluated based on the etch thickness per unit time of the film under given dry etching conditions, and the “etch selectivity” (also referred to as “etch rate selectivity”) of the first film (or first portion) relative to the second film (or second portion) can be evaluated based on the ratio of the chemical resistance of the first film to the chemical resistance of the second film.

[0069] In some embodiments, the method further includes, prior to process (a), the following processes: (i) providing reference deposition conditions and reference dry etching conditions under which a layer structure having a reference topological profile will be formed in a step on a substrate by performing processes (a) and (b); (ii) after comparing the reference topological profile thus obtained with a target topological profile, changing at least one parameter of the reference deposition conditions and / or at least one parameter of the reference dry etching conditions in such a way as to form a layer structure having a topological profile more similar to the target topological profile than the reference topological profile in a step on a substrate; (iii) performing processes (a) and (b) under the changed deposition / dry etching conditions; and optionally (iv) repeating processes (ii) and (iii) until the topological profile thus obtained is substantially equivalent to the target topological profile.

[0070] In some embodiments, at least one parameter of the reference deposition conditions modified in process (ii) is at least one of plasma power, gas selection, gas flow rate, pressure, and temperature in the reaction space where process (a) is performed. In some embodiments, at least one parameter of the reference dry etching conditions modified in process (ii) is at least the temperature of the reaction space where process (b) is performed.

[0071] The technology disclosed herein can be widely applied to various industries, including but not limited to: applications in which steps having sides and lateral surfaces are formed by grooves having sidewalls as sides and bottom and top surfaces as lateral surfaces; applications in which steps having sides and lateral surfaces are part of a 3D NAND structure having a horizontal recess having a depth surface as a side surface and a height surface as a lateral surface; and applications in which steps having sides and lateral surfaces are part of a staircase having a height surface as a side surface and a depth surface as a lateral surface.

[0072] As discussed in this disclosure, the techniques disclosed herein include various embodiments, and each embodiment may include one, two, or more of the following features in any combination. Furthermore, in this disclosure, any one or more features used in one embodiment may be interchangeably (or alternatively) or additionally used in another embodiment, unless otherwise stated or such substitution or addition is not feasible or would have an adverse effect or fail to achieve its intended purpose.

[0073] In one aspect, embodiments include, but are not limited to, any sensory combination of at least one of the following features or two or more of the following features:

[0074] 1) A method for selective dry etching of two different materials (a first material and a second material) based on chemical resistance or etching selectivity, the materials being deposited on a patterned surface of a substrate, wherein the dry etching process includes conformally exposing the patterned surface to fluorine and / or chlorine free radicals generated by etching gases.

[0075] 2)1) method, wherein the etching selectivity of the first material and the second material is adjusted differently in the following ways:

[0076] a. Changing the substrate temperature during the etching process; and / or

[0077] b. Change the film quality of each of the first and second materials deposited on the patterned surface.

[0078] 3)2) method, wherein the material quality is adjusted by changing material deposition parameters, said material deposition parameters including:

[0079] a. Plasma conditions such as RF power, bias power, etc.;

[0080] b. Selection of process gases, including precursor gases;

[0081] c. Process gas flow rate;

[0082] d. Total gas pressure in the reaction chamber used for the deposition process; and / or

[0083] e. Substrate temperature during the deposition process.

[0084] 4)1) method, wherein the first and / or second material is composed of metal oxide, metal nitride, metal carbide or combination thereof (e.g. TiO, ZrO, TiN, MoO, MoC, TiCO, etc.).

[0085] 5)1) method, wherein the first material is composed of a metal compound material and the second material is composed of SiO.

[0086] 6)1) method, wherein the first material is composed of TiO and the second material is composed of SiO or SiN.

[0087] 7)1) method, wherein, in terms of chemical resistance, the mass of the first material is lower than the mass of the second material.

[0088] 8)1) method, wherein the process gas contains F and Ar.

[0089] 9)1) method, wherein the process gas contains F, N and O.

[0090] The method of 10)1), wherein the process gas contains Cl.

[0091] The method in 11)1) uses the following to generate free radicals:

[0092] a. Remote plasma sources (e.g., microwave plasma, CCP, ICP); or

[0093] b. Thermal decomposition process (e.g., hot wire).

[0094] 12)1) method, wherein the reaction chamber for the etching process is clustered with the reaction chamber for the deposition process, and the deposition process and the etching process are performed sequentially and continuously without breaking the vacuum.

[0095] The method of 13)1) wherein the deposition process and the etching process are carried out in the same reaction chamber.

[0096] In another aspect, embodiments include, but are not limited to, at least one of the following features or any sensory combination of two or more of the following features:

[0097] 1) A method for dry etching a SiN film with high selectivity relative to another film made of another material, the film being deposited on a patterned surface of a substrate, wherein the dry etching process includes conformally exposing the patterned surface to fluorine and / or chlorine free radicals generated by etching gases.

[0098] 2)1) method, wherein the other material is SiN, which differs from the SiN constituting the SiN film in terms of film quality such as film density and / or film composition, and the etching gas is a fluorine-containing gas such as SF6 or NF3.

[0099] 3)1) method, wherein a SiN film deposited on a stepped structure on a patterned surface is subjected to highly selective dry etching, and the desired portion of the SiN film is selectively removed relative to the remaining portion of the SiN film due to the difference in film quality.

[0100] 4)1) method, wherein the other material is a dielectric material such as SiO2, SiC, SiCO, Ti oxide, Hf oxide and / or Zr oxide.

[0101] 5)1) method, wherein the etching gas contains F and Ar.

[0102] 6)1) method, wherein the etching gas contains F, N and O.

[0103] 7)1) method, wherein the etching process uses Cl radicals instead of F radicals.

[0104] 8)1) method, in which the following is used to generate free radicals:

[0105] a. Remote plasma sources (e.g., microwave plasma, CCP, ICP); or

[0106] b. Thermal decomposition process (e.g., hot wire).

[0107] The method of 9)2) wherein the etching selectivity of SiN constituting one SiN film and SiN constituting another film is adjusted differently by changing the following process conditions:

[0108] a. Plasma conditions such as RF power, bias power, etc.;

[0109] b. Selection of process gases, including precursor gases;

[0110] c. Process gas flow rate;

[0111] d. Total gas pressure in the reaction chamber used for the deposition process; and / or

[0112] e. Substrate temperature during the deposition process.

[0113] The method of 10)1) wherein the etching selectivity of the SiN film relative to another film which is an oxide (SiO, TiO, ZrO) is adjusted by changing the following conditions:

[0114] a. To change the film density of SiN films relative to oxide films;

[0115] b. Selection of process gases, including precursor gases;

[0116] c. Plasma conditions such as RF power and bias power;

[0117] d. Process gas flow rate;

[0118] e. Total gas pressure in the reaction chamber used for the deposition process; and / or

[0119] f. Substrate temperature during the deposition process.

[0120] The method of 11)1) wherein a reaction chamber for etching process is clustered with a reaction chamber for deposition process, and the deposition process and etching process are performed sequentially and continuously without breaking the vacuum.

[0121] The method of 12)4) wherein the etching selectivity of SiN and another film is adjusted by changing the process temperature during the deposition process.

[0122] In another aspect, the embodiments include, but are not limited to, at least one of the following features or any sensory combination of two or more of the following features:

[0123] 1) A method for adjusting the topological profile of a film formed on a patterned surface of a substrate, the patterned surface being composed of a stepped structure consisting of a horizontal surface (typically a top and bottom surface of a recess) and a vertical surface (typically a sidewall of a recess), the method comprising: (1) depositing a film on the patterned surface of the substrate in a reaction chamber such that a portion of the film deposited on the horizontal surface has different chemical resistance than a portion of the film deposited on the vertical surface; and (2) isotropically dry etching the film in the reaction chamber in such a way that: (a) primarily removes a portion of the film deposited on the horizontal surface to leave primarily or substantially only a portion of the film deposited on the vertical surface, or (b) primarily removes a portion of the film deposited on the vertical surface to leave primarily or substantially only a portion of the film deposited on the horizontal surface.

[0124] 2)1) method, wherein isotropic dry etching is performed using a remote plasma system.

[0125] 3)1) method, wherein the membrane is an insulating membrane.

[0126] 4)3) method, wherein the insulating film is composed of SiN or SiO.

[0127] 5)3) method, wherein the insulating film is deposited using capacitively coupled plasma (CCP).

[0128] The method of 6)4), wherein the insulating film is a SiN film deposited using at least one precursor selected from aminosilane, halosilane, silane and disilane.

[0129] 7)3) method, wherein the insulating film is dry etched in process (b), the process using a fluorine-containing dry gas such as NF3 and / or CF4 as an etchant and using a diluent gas such as Ar, N2 and / or He.

[0130] 8)1) method, wherein the film is deposited in process (a) by plasma-enhanced chemical vapor deposition (PECVD), plasma-enhanced atomic layer deposition (PEALD) or high-density plasma chemical vapor deposition (HDPCVD).

[0131] In some embodiments, remote plasma is used in process (b) for dry etching of the film, which is typically or conventionally used for chamber cleaning. Using remote plasma for dry etching of the film offers significant advantages, including high productivity, i.e., a high etching rate significantly higher than that of wet etching. Due to the high etching rate of remote plasma dry etching, to improve the controllability of the etching rate, the concentration or flow rate of the etchant, such as NF3, can be set, for example, to values ​​typically used for chamber cleaning (e.g., 10% to 90%, 30% to 70%, or about 50% of values ​​typically used for chamber cleaning). Furthermore, when the film is deposited along the surface of the trench, the aspect ratio of the trench can affect the controllability of isotropic dry etching. To mitigate such problems, the film quality of these portions can be adjusted, for example, by varying the deposition pressure in process (a) (the deposition process), to regulate the etching selectivity of the sidewall portions of the film deposited in the trench relative to the top / bottom portions.

[0132] Some aspects and / or embodiments of the present invention will be described in detail by way of example in conjunction with the accompanying drawings, but the present invention is not intended to be limited thereto.

[0133] Figure 23 Some aspects of the embodiments are represented and illustrated by a schematic simplified continuous process scheme (a) that combines deposition and etching in a cluster tool without disrupting the vacuum, and a schematic simplified continuous process scheme (b) that performs deposition and etching in the same reactor. In process scheme (a), a substrate is provided in step S11 (“providing the substrate”), the substrate having a patterned surface consisting of at least one step having a side surface (which may be referred to as a “vertical surface” or “sidewall”) and a top surface (which may be referred to as a “horizontal surface” or “top / bottom surface”). In step S12, the substrate is transferred to reactor chamber 1 (“transfer to RC1”) for deposition. A first dielectric layer (consisting of, for example, SiO material or other oxide material) may be formed on the substrate before the substrate is transferred to reactor chamber 1 or may be formed in reactor chamber 1, whereby the surface of the step is constituted by the first dielectric layer before the second dielectric layer is deposited in reactor chamber 1. In step S13, in reaction chamber 1, under deposition conditions, a second dielectric layer composed of a metal compound (which herein includes not only, for example, TiO and TiN, but also metalloid compounds and silicon compounds, such as SiN) is deposited on a pre-selected region of the first dielectric layer in direct contact with the first dielectric layer (“metal compound deposition”). The second dielectric layer is less resistant to fluorine and / or chlorine radicals than the first dielectric layer.

[0134] In step S14, after the deposition of the second dielectric layer in reaction chamber 1, the substrate is transferred to reaction chamber 2 (“transfer to RC2”) for dry etching. A wafer handling robot can be used to attach the substrate to the wafer transfer chamber, to which reaction chamber 1 is also attached, so that the substrate can be transferred to reaction chamber 2 without exposure to air. In step S15, the second dielectric layer is exposed to fluorine and / or chlorine free radicals under dry etching conditions (“radical etching”), thereby removing at least a portion of the second dielectric layer without removing the first dielectric layer, thereby forming a layer structure with a topological profile on the substrate. Radical etching can be an isotropic etching that primarily or mainly uses radicals rather than ions (preferably with virtually no or very few ions), such that when the second dielectric layer is conformal and homogeneous (in-plane mass uniformity), substantially conformal etching (i.e., virtually no or very little etch directionality) can be performed, resulting in a conformal final layer structure. When the second dielectric layer is non-conformal (e.g., top-dominant deposition) and / or has in-plane mass variations (e.g., side-low quality), radical etching can act as anisotropic etching, resulting in a final layer structure with top-residual or side-residual topological profiles. Radical etching is similar to wet etching, but is much faster.

[0135] exist Figure 23 In process scheme (b), the deposition and etching processes are performed in the same reaction chamber. This simplified process scheme (deposition + etching process flow) allows for SiN pattern definition (side-residual or top-residual) without disrupting the vacuum. In process scheme (b), steps S21, S22, S23, and S24 correspond to steps S11, S12, S13, and S15 in process scheme (a), while in process scheme (b), there is no step corresponding to or equivalent to step S14.

[0136] In some embodiments, the following reactor design can be used to implement process scheme (b), which is shown by way of example only. For radical etching, the plasma does not directly contact the substrate in the reaction chamber. In some embodiments, the possible plasma source is remote plasma, which may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), or microwave plasma (MWP). Therefore, an in-situ CCP in which two electrodes are arranged parallel in the chamber and the substrate is placed between the two electrodes is not suitable for radical etching.

[0137] Figure 11A A schematic simplified configuration of a remote plasma processing device is shown, in which a remote plasma source is integrated into the main processing chamber. Figure 11BA schematic simplified configuration of a remote plasma processing device is shown, in which remote plasma is generated and reactive species are fed into a reaction chamber. The generation of F-radicals can be achieved, for example, by inductively coupled plasma (ICP), capacitively coupled plasma (CCP), or microwave plasma. Figure 11A and 11B In the two illustrated apparatuses, for deposition, in-situ CCP is used by generating plasma between the upper electrode (spray head) 3 and the lower electrode (support) 1 on which the wafer (W) is placed, wherein the upper electrode 3 is connected to the RF power supply 5, and the lower electrode 1 is connected to the low-frequency bias source 4. For free radical etching, Figure 11A The illustrated apparatus uses indirect plasma 8, which is generated between top electrode 2 and upper electrode 3, which are connected to a plasma power source 6 (e.g., an RF power source or a microwave power source). Because plasma 8 is confined in the space between top electrode 2 and upper electrode 3, the wafer (W) is not directly exposed to the plasma, but rather to the free radicals of the plasma, which are fed through upper electrode 3 and reach the surface of the wafer (W). Gas supply line 7 is connected to the top electrode to supply process gases for deposition and / or etchant gases for dry etching.

[0138] In order to perform free radical etching, Figure 11B The illustrated apparatus uses a remote plasma unit 10, which generates plasma 13 within itself. Etching gas is supplied to the remote plasma unit via gas line 12, and the unit is connected to a plasma power supply 9. Because plasma 13 is confined within the remote plasma unit 10, the wafer (W) is not directly exposed to the plasma, but rather to the free radicals of the plasma. These free radicals are fed and pass through gas line 11 connected to the upper plate 2' and through the upper electrode 3 (spray head) to reach the surface of the wafer (W). During film deposition, the remote plasma unit 10 is not activated, and process gas is supplied through gas line 12, the remote plasma unit 10, gas line 11, and the upper electrode (spray head) 3 to the reaction space between the upper and lower electrodes.

[0139] Figure 14A schematic simplified configuration of a plasma processing apparatus equipped with an RF plasma source for deposition and a MW plasma source for dry etching is illustrated by way of example. The MW plasma for dry etching is supplied to the reaction space via a port located on the sidewall of reaction chamber 29, where a wafer (W) is placed on a substrate 21. The MW plasma is generated by a remote plasma unit 28 connected to the MW power supply 24, through which an etchant gas (e.g., SF6) fed to it is converted into free radicals, which are then supplied to the reaction space for dry etching of the wafer surface. To deposit a film on the wafer (W), any suitable CCP system, including any suitable conventional CCP system, can be used, for example, where the RF power supply 25 and gas lines 27 are connected to a spray head (upper electrode) 23 disposed on a top panel 22. Gas lines 27 are used to supply an inert gas (e.g., H2, N2, and / or He) not only for deposition but also for dry etching (if necessary). The substrate serves as a lower electrode and is grounded for deposition. The pressure inside the reaction chamber 29 is controlled by venting gas from the reaction space via a port 26 connected to a TMP (turbomolecular pump) to generate a high vacuum.

[0140] Figure 17 A schematic simplified configuration of a plasma processing apparatus equipped with an RF plasma source and a remote plasma source is shown as an example. This is in contrast to... Figure 11BThis is a variation of the system using a remote plasma unit, similar to the device illustrated. Ideally, this device is combined with a controller programmed to perform the following sequence. In this figure, plasma is excited between the electrodes by providing a pair of parallel, face-to-face conductive plate electrodes 44, 42 in the interior 51 (reaction zone) of the reaction chamber 43, applying HRF power (13.56 MHz or 27 MHz) 60 to one side, and electrically grounding the other side 52. A temperature regulator is provided in the lower platform 42 (lower electrode) to maintain the temperature of the substrate 41 placed thereon at a given temperature. The upper electrode 44 also serves as a spray plate, introducing reactant gas (and rare gas) and precursor gas into the reaction chamber 43 via gas lines 61 and 62 and via the spray plate 44. Additionally, an annular pipe 53 with an exhaust line 47 is provided in the reaction chamber 43 to exhaust the gas in the interior 51 of the reaction chamber 43. Furthermore, dilution gas is introduced into the reaction chamber 43 via gas line 63. Furthermore, a transfer chamber 45 located below the reaction chamber 43 is provided with a sealing gas line 64 to introduce sealing gas into the interior 51 of the reaction chamber 43 via the interior 56 (transfer zone) of the transfer chamber 45. The transfer chamber includes a separation plate 54 for separating the reaction zone and the transfer zone (the gate valve for transferring the wafer into or from the transfer chamber 45 via this plate is omitted in the figure). The transfer chamber also provides an exhaust line 46. In some embodiments, multi-element film deposition and surface treatment are performed in the same reaction space, allowing all steps to be performed continuously without exposing the substrate to air or other oxygen-containing atmospheres. In some embodiments, a remote plasma unit can be used to excite the gas. After film deposition on the patterned surface of the wafer is completed, dry etching is initiated using a remote plasma system 70 connected to a gas line downstream of gas lines 61, 62, and 63 that is connected to a spray head 44. Etching agent gas and inert gas are supplied to the remote plasma system 70 through gas lines 71 and 72, respectively, so that the etchant gas is excited to generate plasma including free radicals. These free radicals are fed into the reaction zone 51 for dry etching.

[0141] exist Figure 23In some embodiments illustrated in (b), because dry etching uses free radicals included in a remote plasma to modulate the topological profile of the layer structure formed in the steps of the substrate, the deposition and dry etching processes can be performed in the same reaction chamber, provided it is equipped with suitable plasma sources for deposition and dry etching. Such a device can have a significantly smaller footprint than conventional separate reaction chambers used for deposition and wet etching, and because dry etching is much faster than wet etching (with a much higher etching rate), throughput can also be significantly increased. Conventionally, some devices are equipped with a remote plasma unit for chamber cleaning. However, since this remote plasma unit is specifically designed for chamber cleaning, (1) cleaning cycles are performed periodically or intermittently according to its set cleaning schedule for maintenance purposes, rather than after each deposition cycle; (2) cleaning conditions are set constant to most effectively clean the inner walls, spray heads, and liners in the chamber, without any adjustment to specifically adjust the topological profile of the individual layer structures formed in the recesses of the substrate to achieve the target topological profile of the final layer structure; and (3) the plasma density used for chamber cleaning is high to effectively remove particulate layers formed on the inner surface of the chamber, which are often visible and therefore require at least micrometer-level control, far exceeding nanometer-level control, because the particulate layers have a thickness of at least micrometer, which is too high for adjusting the topological profile of films or layers that require nanometer-level control (control less than one micrometer, preferably adjusting thicknesses of 100 nm, 50 nm, 20 nm, 10 nm, or less). Furthermore, the plasma generation frequency suitable for chamber cleaning is different from the plasma generation frequency suitable for adjusting the topological profile of the layer structure of the substrate. In some embodiments of the present invention, the deposition process and the dry etching process are adjusted and controlled as an integrated process based on the target topological profile of the final layer structure.

[0142] Figure 15 The process of using one apparatus for deposition and another apparatus for wet etching is illustrated by way of example. Figure 16 A process for deposition and dry etching using a single device is illustrated by way of example. Figure 15 and 16 In the two process schemes illustrated, the deposition process can be performed similarly, wherein the trenched substrate 31 is placed in the reaction chamber ( Figure 15 Tool A in Figure 16In tool C), a directional dielectric film 32 with film properties is formed over the trench by using plasma bombardment. The directionality of the film properties refers to, but is not limited to, differences in properties such as chemical resistance (chemical difference), density (mechanical difference), thickness (structural difference), and / or composition (compositional difference) between a portion of the film on a horizontal surface and a portion of the film on a vertical surface, all of which are associated with etching selectivity. Any suitable method may be used, including any suitable conventional method or those explicitly, implicitly, or inherently described in this disclosure. For example, in some embodiments, such methods disclosed in U.S. Patent No. 9,754,779, published September 5, 2017; U.S. Patent No. 10,468,251, published November 5, 2019; and U.S. Patent No. 10,529,554, published January 7, 2020, the disclosures of which are incorporated herein by reference in their entirety. Figure 15 and 16 Of the two, the film 32 deposited on the substrate 31 is conformal, but... Figure 15 wet etching properties and Figure 16 In terms of the dry etching properties, it has directionality.

[0143] In order to perform etching, Figure 15 In this process, substrate 31 is transferred to another reaction chamber (tool B; wet etching apparatus) to remove one of the top / bottom portions or sidewall portions of the film by wet etching, thereby producing either the side residual topology profile 32' or the top / bottom residual topology profile 32". Figure 16 In this process, instead of transferring the substrate 31 to another reaction chamber, it remains in the same reaction chamber (tool C, dual-function device) to remove one of the top / bottom portions or sidewall portions of the film by dry etching, thereby producing either the side residual topology profile 32' or the top / bottom residual topology profile 32'. Figure 16 In this process, because dry etching is performed within the same reaction chamber, it does not increase the floor space of the reaction chamber and offers high throughput (high etching rate with no downtime due to transfer). Figure 15 In this case, because wet etching is performed in another reaction chamber, the footprint of the two reaction chambers is doubled, and the yield is low (the etching rate is low and time is required for transfer).

[0144] In some embodiments, a combination of deposition and dry etching processes utilizing two layers of efficient dry etching selective deposition can be suitably applied to 3D NAND fabrication. Figure 7A schematic simplified process sequence in the fabrication of 3D DNA ND using fluorine radicals is illustrated by way of example ((a)→(b)→(c)→(d)→(e)→(f)). The structure (e) enclosed in lines provides an illustration of the removal step of a sacrificial layer (e.g., SiN 102) with high desired etch selectivity (>e.g., 1000:1) on an insulating layer (e.g., SiO2 100), wherein the fluorine radical-based process described in this disclosure is used instead of conventional wet etching during this removal step. For example, typical layers and typical layer dimensions are as follows: 100: Insulating layer (30 nm thick SiO2, deposited by PECVD); 101: Substrate; 102: Sacrificial layer (30 nm thick SiN, deposited by PECVD); 103: Channel (polysilicon filled with SiO2); 104: Metal contact (TiN diffusion barrier / W filled). In the accompanying figures, structure (a) illustrates the formation of SiO / SiN stacks; structure (b) illustrates the etching of vias with a diameter of 100 nm; structure (c) illustrates the filling of vias with polysilicon / SiO2; structure (d) illustrates the etching of vias; structure (e) illustrates the sacrificial SiN removal (NF3 / SF6 free radical dry etching); and structure (f) illustrates the formation of metal contacts.

[0145] Figure 8A An illustrative simplified process sequence in the fabrication of 3DNAND using fluorine radicals on a “ladder” is shown as an example ((a)→(b)→(c)→(d)). Figure 8B The use of examples is shown Figure 8AThe final structure fabricated using the process sequence. The structure (d) enclosed by lines provides an illustration of the remaining top etching of the sacrificial layer (e.g., SiN 203). Because the film quality of the sacrificial layer on the vertical surfaces (sidewalls) is significantly lower than that on the horizontal surfaces (top, bottom), this quality difference (e.g., differences in chemical resistance may be attributed to differences in density and / or composition, etc.) leads to selective etching of the sidewall portions relative to the top / bottom portions when using F-radicals. As explained in this disclosure, the quality difference between the top / bottom portions of the film and the sidewall portions can be provided by varying the SiN film deposition parameters. For example, typical layers and their typical dimensions are as follows: 100: Insulating layer (SiO2, 30 nm thick); 101: Substrate; 102: Sacrificial layer (SiN type 1, 30 nm thick, deposited via PECVD); 104: Metal contact (TiN diffusion barrier / W filler); 203: Sacrificial layer (SiN type 2, 10 nm thick, deposited via PEALD using NH3 and DCS); 205: Insulating layer (SiO2, 1000 nm thick, deposited via PECVD); 206: Metal contact (TiN diffusion barrier, W filler). Structure (a) illustrates the formation of SiN / SiO stacks; structure (b) illustrates the formation of steps; structure (c) illustrates the sacrificial SiN deposition; structure (d) illustrates the top remaining etch of SiN (NF3 / SF6 radical etch). Figure 8B Illustrations are provided for further processing up to the final structure.

[0146] Figure 9A schematic simplified process sequence ((a)→(b)→(c)→(d)→(e)) in sidewall spacer formation or spacer-defined dual patterning (SDDP) using fluorine radicals is illustrated by way of example. Similar to Figure 8, there are also applications where a residual SiN film on the sidewalls is required. By ensuring that the film density and / or quality of a portion of the SiN film deposited on the sidewalls is higher than that of those deposited on the top and bottom, etch selectivity of the sidewall portions relative to the top / bottom portions can be achieved when using F-radicals. The desired thickness and properties of the residual film can be achieved by adjusting the compositional differences. This technique can be effectively used for sidewall spacer formation or spacer-defined dual patterning (SDDP). For example, typical layers and typical layer dimensions are as follows: 300: substrate material; 301: core material; 302: SiN (vertical film differs from top film quality (composition and / or density). The quality of the film on the horizontal surface (top, bottom) (SiN 302) is significantly lower than that of the film on the vertical surface (sidewalls). This quality difference (e.g., differences in chemical resistance may be attributed to differences in density and / or composition, etc.) leads to selective etching of the top portion relative to the sidewall portion when using F-radicals. Structure (b) provides an illustration of pattern formation; structure (c) provides an illustration of sacrificial SiN deposition; structure (d) provides an illustration of the side residual (top / bottom dominant) etching of SiN by NF3RPU with PR power (achieving high etch selectivity of SiN relative to SiO2 >, for example, 1000); structure (e) provides an illustration of core etching (optional).

[0147] Figure 10 This illustrates a schematic, simplified, continuous process scheme that combines deposition and etching in clustered tools without disrupting the vacuum. This process scheme is related to... Figure 23 The diagrams in (a) are essentially equivalent, where steps S1, S2, S3, S4, and S5 correspond to respectively Figure 23 In (a), S11, S12, S13, S14, and S15 differ in that... Figure 10 The film deposited therein is specifically composed of SiN. Figure 23 The film deposited in it is composed of metal compounds. Figure 23 The process scheme illustrated in (b) can also be applied to SiN films.

[0148] Those skilled in the art will recognize that the apparatus includes one or more controllers (not shown) programmed or otherwise configured to enable deposition and the reactor cleaning processes described elsewhere herein. As will be understood by those skilled in the art, the one or more controllers may be connected to various power sources, heating systems, pumps, robotic devices, and gas flow controllers or valves of the reactor.

[0149] The invention is further explained with reference to the following examples. However, these examples are not intended to limit the invention. In examples where no conditions and / or structures are specified, such conditions and / or structures can be readily provided by those skilled in the art as routine experimental matters in light of this disclosure. For example, in the following examples, any suitable precursors for depositing dielectric films composed of TiO2, TiN, etc., such as those disclosed in U.S. Patent No. 9,556,516, published January 31, 2017, and / or U.S. Patent No. 9,171,716, published October 27, 2015, the disclosures of which are incorporated herein by reference in their entirety. Additionally, for example, in the following examples, any suitable precursors for depositing dielectric films composed of SiO2, SiN, etc., such as those disclosed in U.S. Patent No. 8,197,915, published June 12, 2012, and / or U.S. Patent No. 9,824,881, published November 21, 2017, may be selected and used by a person skilled in the art as a routine experimental matter, the disclosures of which are incorporated herein by reference in their entirety. Furthermore, in some embodiments, the numerical values ​​applied in specific examples may be modified by at least ±50%, and said values ​​are approximate.

[0150] Example

[0151] Reference Example 1

[0152] TiO2 films were deposited on each substrate by PEALD under the following deposition conditions:

[0153] Plasma: O2 plasma (reactive gas: O2 1000 sccm; power: 192 W, 13.56 MHz); deposition temperature: 190 °C; deposition pressure: 250 Pa; film thickness: 24 nm.

[0154] Next, one of the substrates with the TiO2 film was exposed to NF3 remote CCP plasma (NF3 radicals) at a temperature of 100°C, and the other substrate with the TiO2 film was exposed to NF3 remote CCP plasma (NF3 radicals) at a temperature of 200°C. The NF3 remote plasma unit (PRU) was set under the following conditions (hereinafter referred to as "XP5"):

[0155] Power: 900W

[0156] • Frequency: 13.56MHz

[0157] Pressure: 60 Pa

[0158] • Flow rate: 2.8 / 200 sccm NF3 / Ar

[0159] Temperature: 200℃

[0160] Figure 19 The graph shows the effect of exposure to remote plasma for a period of time. Figure 19 The duration shown is the etching thickness of each TiO2 film. Figure 19 As shown, it is confirmed that the dry etching rate is a function of plasma (free radical) exposure time and etching temperature.

[0161] Reference Example 2

[0162] A TiO2 film (referred to as "TiO-1") was deposited on the substrate by PEALD under the same deposition conditions as in Reference Example 1. Another TiO2 film (referred to as "TiO-2") was deposited on the substrate by PEALD under the same deposition conditions as in Reference Example 1, except that the precursor feed time during the ALD process was 0.05 s for TiO-1 and 0.4 s for TiO-2, and the film thickness of TiO-1 was 24 nm while that of TiO-2 was 18 nm.

[0163] SiO2 films (referred to as "SiO-1") are deposited on substrates by PEALD under the following deposition conditions:

[0164] Plasma: O2 plasma (reactive gas: O2; power: 500W, 13.56MHz); deposition temperature: 200℃; deposition pressure: 400Pa; film thickness: 30nm.

[0165] Another SiO2 film (referred to as "SiO-2") was deposited on the substrate by PEALD under the same deposition conditions as those used for SiO-1, except that the deposition temperature was 75°C and the RF power was 50W.

[0166] Next, the substrate containing TiO-1, TiO-2, SiO-1, and SiO-2 was exposed to NF3 remote CCP plasma (NF3 radicals) at 200°C for 40 s. The NF3PRU was set to condition XP5.

[0167] Figure 20 The graph shows the etching thickness of each TiO-1, TiO-2, SiO-1, and SiO-2 element. Figure 20 As shown, the etching selectivity varies with material composition (SiO or TiO) and mass (-1 or -2), indicating that etching selectivity can be tuned by changing deposition conditions and / or selecting composition, thus allowing for greater manipulation of etching selectivity.

[0168] Example 1

[0169] A TiO2 film was deposited on a trenched substrate using PEALD in the same manner as in Reference Example 1. This TiO2 film corresponds to TiO-1 in Reference Example 2. Figure 21A A scanning electron microscope (SEM) image of a cross-section of a titanium oxide film (TiO-1) formed on a patterned structure prior to fluorine radical etching to form a layered structure with a top / bottom residual topological profile is shown. Figure 21A As shown, TiO-1 is deposited in a top-dominant deposition scheme.

[0170] Next, the substrate with the TiO-1 film was exposed to NF3 remote CCP plasma (NF3 radicals) at a temperature of 200°C. The NF3 remote plasma unit (PRU) was set to XP5 conditions. Figure 21B A scanning electron microscope (SEM) image of a cross-section of a titanium oxide film (TiO₁) formed on a patterned structure after fluorine radical etching to form a layered structure with a topologically remaining profile is shown. Figure 21B As shown, NF3 radical etching is conformal etching, but its etching effect is selective, where TiO2 is etched while the underlying Si is not (it can be further protected by interlayer oxides by adding oxygen to the process gas). Because NF3 radical etching is conformal, the top-dominant deposition scheme strongly influences the topological profile of the final layer structure (which is the top residual topological profile), where all portions of the TiO-1 film deposited in the trenches and on the top surface are etched substantially uniformly or homogeneously, resulting in virtually no film remaining on the sidewalls and at the bottom of the trenches, while portions of the film on the top surface are retained, although the thickness of these portions is reduced to some extent. This example demonstrates that the top residual topological profile of the final layer structure can be achieved by combining deposition of the film using a top-dominant deposition scheme with radical etching of the film using a conformal etching scheme.

[0171] Example 2

[0172] A TiO2 film was deposited on a trenched substrate using PEALD in the same manner as in Reference Example 2. This TiO2 film corresponds to TiO-2 in Reference Example 2. Figure 22A A scanning electron microscope (SEM) image of a cross-section of a titanium oxide (TiO-2) film formed on a patterned structure prior to fluorine radical etching to form a layered structure with a conformal topological profile is shown. Figure 22A As shown, TiO-2 is deposited using a conformal deposition scheme.

[0173] Next, the substrate with the TiO-2 film was exposed to NF3 remote CCP plasma (NF3 radicals) at a temperature of 200°C. The NF3 remote plasma unit (PRU) was set to XP5 conditions. Figure 22B A scanning electron microscope (SEM) image of a cross-section of a titanium oxide (TiO₂) film formed on a patterned structure after fluorine radical etching to form a layered structure with a conformal topological profile is shown. Figure 22B As shown, NF3 radical etching is conformal etching, but its etching effect is selective, where TiO2 is etched while the underlying Si is not (it can be further protected by interlayer oxides by adding oxygen to the process gas). Because NF3 radical etching is conformal, the conformal deposition scheme strongly influences the topological profile of the final layer structure (which is a conformal topological profile), where all portions of the TiO-2 film deposited in the trenches and on the top surface are etched substantially uniformly or homogeneously, resulting in a final layer structure with a conformal topological profile, although the thickness of all portions of the film is reduced to some extent. This example demonstrates that a conformal topological profile of the final layer structure can be achieved by combining a conformal / uniform quality deposition scheme with radical etching of the film using a conformal etching scheme.

[0174] TiO-1 and TiO-2 in such Figure 20 The etching conditions shown have similar etching rates, but as Figure 21A (top dominant deposition) and Figure 22A As shown in (conformal deposition), different deposition profiles are achieved by varying at least one of the deposition process parameters (here, the precursor feed time). To form other deposition profiles with conditions and / or structures not specified herein, such conditions and / or structures can be readily provided by those skilled in the art as routine experimental matters without excessive burden, in light of this disclosure. Combined with conformal etching (radical etching), different deposition profiles produce, as shown... Figure 21B and 22B Different topological profiles observed in [the text].

[0175] Reference Example 3

[0176] Various SiN films (SiN-1 to SiN-7) and SiO films were deposited on the substrate under the following deposition conditions:

[0177] SiN-1 (PEALD): Deposition temperature 450℃; Deposition pressure: 3,000Pa; Plasma: N2 plasma (reactive gas: N2; power: 880W, 13.56MHz; plasma duration: 3.3s); Film thickness: 35nm.

[0178] SiN-2 (PEALD): Deposition temperature 450℃; Deposition pressure: 350Pa; Plasma: N2 plasma (reactant gas: N2; power: 880W, 13.56MHz; plasma duration: 3.3s); Film thickness: 50nm.

[0179] SiN-3 (PEALD): Deposition temperature 100℃; Deposition pressure: 350Pa; Plasma: N2 plasma (reactive gas: N2; power: 115W, 13.56MHz; plasma duration: 3.3s); Film thickness: 30nm.

[0180] SiN-4 (PEALD): Deposition temperature 450℃; Deposition pressure: 4 Torr; Plasma: NH3 plasma (reactive gas: NH3; power: 100W, 13.56MHz); Film thickness: 45nm.

[0181] SiN-5 (PEALD): Deposition temperature 450℃; Deposition pressure: 3 Torr; Plasma: NH3 plasma (reactive gas: NH3; power: 125W); Film thickness: 50nm.

[0182] SiN-6 (PRU): The same as those used for SiN-1, except that remote CCP plasma is used.

[0183] SiN-7 (LPCVD-SiN; standard or reference SiN film).

[0184] SiO(PEALD): Same as those used for SiO-1 (Reference Example 2); Film thickness: 40 nm.

[0185] SiN-1, SiN-2, SiN-3, and SiN-6 used the same first precursor, while SiN-4 and SiN-5 used the same second precursor, different from the first precursor. The deposited SiN films ranged in thickness from 25 nm to 55 nm and were deposited on silicon substrates using different precursors and plasma conditions via PEALD or other processes. A standard sample (SiN-7) was deposited using low-pressure CVD with NH3 and SiH2Cl2. The density of the SiN-7 film was 3.18 g / cm³. 3 The essence here is that each film has a different density and / or different hydrogen content, etc., and these differences determine its etching rate and / or RI (refractive index). Therefore, the RI of the film can be used to estimate the etching rate (e.g., regarding...). Figure 4A and 4B (As discussed herein). In order to deposit these films for which conditions and / or structures are not specified herein, in view of this disclosure, those skilled in the art can readily provide such conditions and / or structures as routine experimental matters without much burden.

[0186] Next, the SiN film was exposed to NF3 remote CCP plasma (NF3 radicals) under XP5 conditions, except that the chamber temperature was 25°C. The substrate with the SiO film was exposed to SF6 radicals instead of NF3 radicals. It should be noted that separate experiments confirmed that not only SF6 radicals are effective on the SiO film, but also NF3 radicals are effective on it.

[0187] Figure 1 The graph shows the relationship between the etching thickness of the different films and the NF3 remote plasma exposure time. Figure 1 The etching thickness of various SiN and SiO films with different film densities and / or compositions was plotted as a function of NF3 remote plasma exposure time. For example... Figure 1 As shown, it is confirmed that the dry etching rate is a function of plasma (free radical) exposure time and film quality, and the dry etching rate of the film can be adjusted by adjusting the film quality in order to set a more appropriate etching selectivity for one film relative to another to form the target layer structure.

[0188] It should be noted that films composed of TiO2, ZrO2, etc. are deposited by PEALD in a manner similar to SiO2 and exhibit etch selectivity similar to SiO2. Figure 13 The graph shows the etching thickness of different oxide films when exposed to remote plasma.

[0189] Comparative Example 1

[0190] SiN-1 to SiN-6 and SiO films were formed on the substrate in the same manner as in Reference Example 3, and then wet etching (dHF100:1) was performed on the films instead of the free radical dry etching used in Reference Example 3.

[0191] Figure 2 The graph shows the relationship between the etching thickness of different SiN and SiO films and the HF wet etching exposure time. As can be seen from the figure, the SiN etching rate of NF3 remote plasma is very similar to that of wet etching. Furthermore, NF3 remote plasma etching is selective, preventing SiO2 from being etched. Figure 1 As shown in the image, HF etched SiO2, as... Figure 2 As shown in the image.

[0192] Reference Example 4

[0193] Figure 3 For curve graphs, based on Figure 1 and 2The etch selectivity of the different SiN films discussed above in NF3 remote plasma etching was redrawn by comparing it with the etch thickness of the SiN-1 film (the etch thickness of the reference SiN-1 film). The etch selectivity of a SiN film relative to a reference SiN film is defined as the ratio of the etch rate (or etch thickness) of a SiN film to the etch rate (or etch thickness) of the reference SiN film under reference dry etching conditions. Here, the SiN-1 film is chosen as the reference SiN film. Figure 3 As shown, the etching selectivity of the SiN film relative to the SiN-1 film can be adjusted by changing the deposition conditions of SiN-2 to SiN-6 (leading to differences in composition, structure, physical properties, and chemical properties between the SiN film and the SiN-1 film). Figure 3 As shown, the etch selectivity of the SiN film can be adjusted from 1 to 50 during NF3 radical etching. The SiO2 film is essentially not etched by NF3 radical etching (within the error limit). Therefore, when using the SiO2 film as a reference film, the etch selectivity of the SiN film is at least 5 for SiN-1 and at least 100 for SiN-2 (i.e., SiN-2 is etched at least 100 times faster than SiO2).

[0194] By replacing NF3 with SF6 generated in a remote microwave plasma (2.45 GHz, 50 W, 2 Pa), the etch rate difference between SiN films can be further increased to a maximum of 100. The etch selectivity of SiN films relative to SiO2 or other oxides is at least 25 for SiN-1 and at least 4000 for SiN-2 (after accounting for measurement errors). It should be noted that the longer the experimental duration, the smaller the measurement error becomes, which means that the etch selectivity may approach perfect (infinite).

[0195] Reference Example 5

[0196] Further analysis was performed on the SiN films composed of SiN-1 to SiN-7 as described in Reference Example 3, wherein their refractive indices were measured. Figure 4A The graph, comparing the etching rate of SiN-1 with that of SiN-1 (as a reference), shows the relationship between the etching rate of different SiN films and their refractive index during remote plasma etching with NF3. Figure 4AAs shown, the refractive index of the SiN film is strongly correlated with the dry etching rate of it by free radicals (especially in the refractive index range of about 1.95 or lower, where the etching rate increases linearly with decreasing refractive index for NF3 remote plasma). Since the dry etching properties of the film are attributable to and related to its composition and density, it should be understood that the refractive index can be used as an indirect measure of its composition and density. For example, a film with a lower density and / or lower quality (inferior composition) compared to another film will produce a lower refractive index than said other film. Accordingly, although the density of SiN-6 film alone is known to be 3.18 g / cm³, this is not the case. 3 However, it can be reasonably determined that other SiN films with a lower refractive index than SiN-6 films have lower density and / or lower quality (inferior composition) than SiN-6 films.

[0197] Figure 4B The graph shows the relationship between the etching rate of different SiN films (such as SiN-1 to SiN-6 described in Comparative Example 1) and the refractive index of different films during HF wet etching, compared to the etching rate of SiN-1 (referencing the etching rate of SiN-1). Figure 4B It is evident that for HF wet etching, the dependence of the etching rate on the refractive index is not as direct or linear as for NF3 remote plasma etching, and greater variations are observed between samples.

[0198] Reference Example 6

[0199] Further analysis was performed on the SiN films composed of SiN-1 to SiN-6 as described in Reference Example 3, including the analysis of their composition / density. Figure 5 Fourier transform infrared (FTIR) spectra (color) of different SiN films with different compositions and densities, where the extinction coefficient (absorbance normalized to film thickness) is plotted against the wavenumber. Figure 5 The values ​​indicate the absorption peaks in each film associated with the presence of Si-N, NH, Si-H, and CO2 bonds. The varying sizes of the Si-N peaks indicate density differences between films, while the presence of NH bonds, etc., indicates compositional differences. It should be noted that not all bonds can be measured by FTIR, meaning it cannot provide a complete picture of compositional differences.

[0200] Figure 6 The graph shows the relationship between the etching rate of the SiN film and... Figure 5The relationship between the Si-N peak areas is indicated in the diagram. Data shows that the lower the Si-N bonding content (lower density) of the SiN film, the higher the etching rate. Therefore, the etching rate of the SiN film can be adjusted by changing the amount of Si-N bonding (by changing the deposition process parameters). Given this disclosure, and particularly the guidance provided herein, those skilled in the art can adjust deposition conditions to regulate the etching rate as a routine experimental matter without much burden.

[0201] Example 3

[0202] A SiN-4 film was deposited on a substrate with trenches (depth 250 nm, aperture width 150 nm) using PEALD in the same manner as in Reference Example 3. The thickness of the SiN-4 film on the top surface of the substrate was 26 nm. Additionally, a SiN-3 film was deposited on a substrate with trenches (depth 250 nm, aperture width 150 nm) using PEALD in the same manner as in Reference Example 3. The thickness of the SiN-3 film on the top surface of the substrate was 29 nm. The target topology profile of the final layer structure using the SiN-4 film is the side residual topology profile, while the target topology profile of the final layer structure using the SiN-3 film is the top / bottom residual topology profile.

[0203] By manipulating the process parameters as discussed in this disclosure, the deposition conditions for SiN-4 films have been changed to perform top / bottom low-quality (low-density) deposition:

[0204] (i) Provide reference deposition conditions and reference dry etching conditions (here, condition XP5 for conformal etching), and form a SiN film with a reference topological profile on the trenched surface of the substrate by performing a PEALD deposition process under the reference deposition conditions and a free radical etching process under condition XP5.

[0205] (ii) After comparing the obtained reference topological profile with the target topological profile, at least one parameter of the reference deposition conditions is changed in a manner that forms a layer structure on the substrate having a topological profile that is closer to the target topological profile than the reference topological profile (e.g., increasing RF power and / or decreasing process pressure, and / or changing precursor and / or reactive gas), and a PEALD deposition process and a free radical etching process are performed under the changed deposition conditions (dry etching conditions – condition XP5 unchanged); and

[0206] (iii) Repeat process (ii) until the obtained topology profile is substantially close to or equivalent to the target topology profile.

[0207] Similarly, by manipulating the process parameters as discussed in this disclosure, the deposition conditions for SiN-3 films have been changed to perform low-quality (low-density) side deposition.

[0208] Next, substrates with SiN-4 and SiN-3 films were exposed to NF3 remote CCP plasma (NF3 radicals) at 25°C. The NF3 remote plasma unit (PRU) was set to XP5 conditions.

[0209] Figure 12A A scanning electron microscope (SEM) image of a cross section of a SiN-4 film formed on a patterned structure after fluorine radical etching according to a top / bottom removal scheme is shown. Figure 12B Scanning electron microscopy (SEM) images of cross-sections of SiN-3 films formed on patterned structures following fluorine radical etching according to a side-removal scheme are shown. These figures confirm that the topological profile of the final layer structure after dry etching can be adjusted by modifying deposition conditions and / or the mass (e.g., density) difference between the side and top portions of the deposited film.

[0210] Examples 4 to 6

[0211] exist Figure 18B SiN films A, B, and C were deposited on a trenched substrate using PEALD under the deposition conditions shown in the figure. The thickness of each SiN film is [missing information]. Figure 18A As shown in the image. Figure 18A A scanning transmission electron microscope (STEM) image of a cross-section of the SiN film (“AsDepo”) is also shown. Figure 18A As shown, SiN film A is conformal (with 89% conformality), while SiN films B and C are top-dominant (with 67% and 60% conformality, respectively). Furthermore, SiN films A and B and C are deposited according to side-low quality schemes and top / bottom-low quality schemes, respectively, such that after exposure to conformal (isotropic) dry etching, SiN film A has a top residual topographic profile, while SiN films B and C have side-residual topographic profiles. The difference between SiN films B and C lies in the opening width of the trenches on which they are deposited, where the conformality of SiN films B and C differs due to the loading effect despite the identical deposition conditions.

[0212] Next, in Figure 18B The SiN films A, B, and C are exposed to NF3 remote CCP plasma (NF3 radicals) under dry etching conditions, as shown in the figure. The resulting layer structure... Figure 18A As shown in (“After dry etching”). Figure 18AAs shown, by exposing SiN films A, B, and C to conformal (isotropic) dry etching, with conformality varying from 89% to 44% (“conformal” to “top-remaining”), from 67% to 132% (“top-dominant” to “side-remaining”), and from 60% to 132% (“top-dominant” to “side-remaining”), respectively, the difference in film quality (density or etch rate) between the side portions of the film deposited on the sidewalls and the lateral portions deposited on the top / bottom of the trenches (“side-low quality” in film A, “top / bottom-low quality” in films B and C) leads to differences in etch selectivity (or etch rate selectivity) between the side portions and lateral portions of each film. These figures demonstrate that the topological profile of the final layer structure after dry etching can be adjusted by modifying deposition conditions and / or the quality (e.g., density) differences between the side portions and lateral portions of the deposited film.

[0213] Those skilled in the art will understand that various modifications can be made without departing from the spirit of the invention. Therefore, it should be clearly understood that the form of the invention is merely illustrative and not intended to limit the scope of the invention.

Claims

1. A method for manufacturing a layered structure having a target topological profile in a step having side faces and lateral surfaces, the method comprising a process: (a) A dielectric layer is deposited on a pre-selected region of a substrate under a first deposition condition, wherein the dielectric layer comprises a first portion and a second portion, and wherein the second portion is a portion whose tolerance to fluorine and / or chlorine radicals is tuned under a first dry etching condition to a different tolerance to fluorine and / or chlorine radicals than that of the first portion under the first dry etching condition; and (b) Exposing the first and second portions of the dielectric layer obtained in process (a) to fluorine and / or chlorine radicals formed using remote plasma under the first dry etching conditions, thereby removing at least a portion of the second portion of the dielectric layer, thereby forming a layer structure having the target topological profile on the substrate, wherein, The target topological profile is a lateral residual topological profile or a lateral surface residual topological profile. The first portion is deposited under a different set of deposition conditions than the second portion, thereby adjusting the tolerance of the second portion to fluorine and / or chlorine radicals under the first dry etching conditions, wherein the deposition conditions include at least one of plasma power, gas selection, gas flow rate, pressure, and temperature in the reaction space.

2. The method of claim 1, wherein a first portion of the dielectric layer is formed by a first dielectric layer deposited on the substrate, and a second portion of the dielectric layer is formed by a second dielectric layer deposited on the first dielectric layer, wherein the second dielectric layer has a tolerance to fluorine and / or chlorine radicals adjusted such that the etch selectivity of the second dielectric layer relative to the first dielectric layer is 5 or higher, wherein the etch selectivity is defined as the ratio of the etch rate of the second dielectric layer to the etch rate of the first dielectric layer under the first dry etching conditions.

3. The method of claim 2, wherein the first dielectric layer and the second dielectric layer are of the same type, wherein the main chemical bonds constituting the first dielectric layer and the second dielectric layer are the same.

4. The method of claim 1, wherein a first portion of the dielectric layer is deposited on the side surface and a second portion of the dielectric layer is deposited on the side surface, wherein the first portion and the second portion have different tolerances to fluorine and / or chlorine radicals under the first dry etching conditions, such that the etch selectivity of one of the first portion and the second portion is 1.5 or higher, wherein the etch selectivity of the first portion and the second portion is defined as the ratio of the etch rate of the first portion and the second portion to the etch rate of the other portion under the first dry etching conditions.

5. The method of claim 4, wherein the first portion of the dielectric layer and the second portion of the dielectric layer have different thicknesses.

6. The method according to claim 1, wherein process (a) and process (b) are carried out in the same chamber.

7. The method according to claim 6, wherein the fluorine and / or chlorine radicals are fluorine radicals generated in the same chamber by a fluorine- and nitrogen-containing gas and a rare gas.

8. The method according to claim 1, wherein the method further comprises a process prior to process (a): (i) Provide reference deposition conditions and reference dry etching conditions, under which a layer structure having a reference topological profile is formed in the steps on the substrate by performing processes (a) and (b); (ii) After comparing the reference topological profile thus obtained with the target topological profile, at least one parameter of the reference deposition conditions and / or at least one parameter of the reference dry etching conditions are changed in such a way as to form a layer structure having a topological profile more similar to the target topological profile than the reference topological profile in the step on the substrate. (iii) Processes (a) and (b) were performed under modified deposition / dry etching conditions.

9. The method according to claim 8, further comprising: (iv) Repeat processes (ii) and (iii) until the topological profile obtained is equivalent to the target topological profile.

10. The method according to claim 8, wherein at least one parameter of the reference deposition conditions changed in process (ii) is at least one of plasma power, gas selection, gas flow rate, pressure and temperature in the reaction space where process (a) is performed.

11. The method according to claim 8, wherein at least one parameter of the reference dry etching conditions changed in process (ii) is at least the temperature of the reaction space in which process (b) is performed.

12. The method of claim 1, wherein the step having the side surface and the lateral surface is formed by a groove having a sidewall as the side surface and a bottom surface and a top surface as the lateral surface.

13. The method of claim 1, wherein the step having the side surface and the lateral surface is part of a 3DNAND structure, the structure having a horizontal recess having a depth-direction surface as the side surface and upper and lower height-direction surfaces as the lateral surface.

14. The method of claim 1, wherein the step having the side surface and the lateral surface is part of a step having a height surface as the side surface and a depth surface as the lateral surface.

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