Substrate processing method

Abstract

This disclosure discloses a substrate processing method for forming an air gap, comprising: forming a plurality of deposition inhibitor sites in a lower space between a first protrusion and a second protrusion; and forming a plurality of film formation sites and an intermediate insulating layer on the first protrusion and the second protrusion, wherein the intermediate insulating layer is selectively formed in an upper space between the first protrusion and the second protrusion by means of the deposition inhibitor sites and the film formation layer, thereby forming an air gap between the first protrusion and the second protrusion.

Description

[Technical Field]

[0001] One or more embodiments of this disclosure relate to a substrate processing method, particularly one that forms an air gap in a gap between multiple patterned structures. [Previous Technology]

[0002] As line widths decrease and semiconductor memory devices become more integrated, the area of ​​dielectric materials (e.g., capacitors) increases while the thickness of the dielectric decreases. Certain problems (e.g., leakage current) can occur in this dielectric due to electron tunneling. To solve these problems, high-k materials are used as dielectrics, but issues such as leakage current or metal element diffusion can still occur due to the interaction between the bit lines of the memory device and the metal.

[0003] To address these issues, low-k materials (which are insulating materials) are being used, and various devices are being developed that utilize an air gap spacer, which is made of air, a material with the lowest dielectric constant. For example, Korean Patent Disclosure No. 10-2010-0122701 discloses a process for forming such an air gap. Specifically, this document discloses a technical concept in which an insulating film is formed between metal wires, and a deposition process is performed to form an overhang, through which an air gap is formed. [Summary of the Invention]

[0004] One or more embodiments of this disclosure include a substrate processing method that can prevent interference between patterned structures by forming an air gap of sufficient size.

[0005] Additional features will be described in part below, while others will be understood from the description or learned by practicing the embodiments presented in this disclosure.

[0006] According to one or more embodiments, the substrate processing method includes: forming a plurality of first terminated sites on a patterned structure, the patterned structure including a first protrusion and a second protrusion; forming a plurality of second terminated sites different from the first terminated sites on the patterned structure having the first terminated sites; and forming a first layer on the first terminated sites and the second terminated sites.

[0007] According to one example of this substrate processing method, the substrate processing method may further include forming a protective layer on the patterned structure, wherein the first end caps and the second end caps may be formed on one surface of the protective layer.

[0008] According to another example of this substrate processing method, the first end capping sites may be located in a first portion of the protective layer in the lower part of the pattern structure, and the second end capping sites may be located in a second portion of the protective layer in the upper part of the pattern structure.

[0009] According to another example of this substrate processing method, the formation of the first layer may be suppressed on the first portion by the first end capping sites and may be promoted on the second portion by the second end capping sites.

[0010] According to another example of this substrate processing method, these first end capping sites may be fluorine-terminated sites.

[0011] According to another example of this substrate processing method, these second capping sites may be hydrogen-terminated sites.

[0012] According to another example of this substrate processing method, the formation of the first layer may include: supplying a source gas that is reactive with the second end caps; and supplying a reactive gas.

[0013] According to another example of this substrate processing method, the source gas may include a silicon precursor, and Si-H end caps may be formed by supplying the source gas.

[0014] According to another example of this substrate processing method, the formation of the Si-H end cap sites can be suppressed at these first end cap sites and promoted at these second end cap sites.

[0015] According to another example of this substrate processing method, the formation of these first end cap sites can be performed under plasma conditions at a first frequency, and the formation of these second end cap sites can be performed under plasma conditions at a second frequency greater than the first frequency.

[0016] According to another example of this substrate processing method, the formation of these first end caps can be performed under a first process pressure, and the formation of these second end caps can be performed under a second process pressure greater than the first process pressure.

[0017] According to one embodiment of this substrate processing method, the substrate processing method may further include forming a second layer on the first layer. In an alternative embodiment, the substrate processing method may further include forming at least one end point on the first layer between forming the first layer and forming the second layer.

[0018] According to another example of this substrate processing method, during the formation of these first end caps, a first cycle including the supply of a fluorine-containing gas may be performed at least once.

[0019] According to another example of this substrate processing method, the fluorine-containing gas may include NF3.

[0020] According to another example of this substrate processing method, during the formation of these second end caps, a second cycle including supplying one of the hydrogen-containing gases may be performed at least once.

[0021] According to another example of this substrate processing method, the hydrogen-containing gas may include H2.

[0022] According to another embodiment of this substrate processing method, at least a portion of an intermediate insulating layer may be formed to cover the pattern structure, an air gap may be formed between the first protrusion and the second protrusion, and the intermediate insulating layer includes the first layer.

[0023] According to another example of this substrate processing method, the air gap may include a gas containing fluorine.

[0024] According to one or more embodiments, a substrate processing method includes: forming a protective layer on a patterned structure, the patterned structure including a first protrusion and a second protrusion; supplying a fluorine-containing gas under a first plasma condition of a first frequency and a first process pressure to form a plurality of fluorine-terminated sites on the protective layer; purging the fluorine-containing gas; supplying a hydrogen-containing gas under a second plasma condition of a second frequency higher than the first frequency and a second process pressure higher than the first process pressure to form a plurality of hydrogen-terminated sites on the protective layer; purging the hydrogen-containing gas; and supplying a silicon-source gas to form a plurality of Si-H-terminated sites. (sites), wherein the formation of these Si-H end-capping sites is promoted at these hydrogen end-capping sites and inhibited at these fluorine end-capping sites; purging the silicon-containing source gas; forming an intermediate insulating layer on the protective layer by supplying a reactive gas that is reactive with these Si-H end-capping sites; and purging the reactive gas.

[0025] According to one or more embodiments, the substrate processing method includes: forming a plurality of deposition inhibitor sites in a lower space between a first protrusion and a second protrusion; and forming an intermediate insulating layer on the first protrusion and the second protrusion, wherein the intermediate insulating layer is selectively formed in an upper space between the first protrusion and the second protrusion by means of the deposition inhibitor sites, and thus an air gap is formed between the first protrusion and the second protrusion.

Implementation Method

[0027] Several embodiments will now be described in detail, examples of which will be presented with reference to the accompanying drawings, wherein the same reference numerals in the drawings represent similar elements. In this regard, the embodiments may take different forms and should not be construed as limited to the description set forth in this specification. Therefore, the embodiments are described below only by reference to the drawings to explain the various forms of this specification. As used herein, the term "and / or" includes any and all combinations of one or more of the associated list items. When a statement such as "...at least one of" precedes the list of elements, it modifies the entire list of elements rather than individual elements of the list.

[0028] In the following description, one or more embodiments will be described more fully with reference to the accompanying drawings.

[0029] In this regard, the embodiments may take different forms and should not be construed as limited to the description set forth in this specification. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0030] The terminology used herein is for the purpose of describing particular embodiments and is not intended to limit the disclosure. Unless the context clearly indicates otherwise, the singular forms “a” and “the” as used herein are intended to include the plural forms as well. It is further understood that the terms “comprising” and / or “including” as used herein indicate the presence of a group of said features, integrals, steps, processes, components, and / or such groups, but do not exclude the presence or addition of one or more other features, integrals, steps, processes, components, and / or such groups. As used herein, the terms “and / or” include any and all combinations of one or more of the associated list items.

[0031] It is worth noting that although ordinal terms such as first, second, etc. may be used herein to describe various components, parts, regions, layers, and / or segments, these components, parts, regions, layers, and / or segments should not be limited by these ordinal terms. These terms do not represent any order, quantity, or importance, but are only used to distinguish one component, region, layer, and / or segment from another component, region, layer, and / or segment. Therefore, without departing from the teachings of the embodiments, the first component, part, region, layer, or segment discussed below may be referred to as the second component, part, region, layer, or segment.

[0032] In this disclosure, "gas" may include evaporated solids and / or liquids, and may include a single gas or a mixture of gases. In this disclosure, the process gas introduced into a reaction chamber via a spray head may include a precursor gas and an additive gas. The precursor gas and the additive gas may generally be introduced as a mixed gas, or may be introduced separately into a reaction space. The precursor gas may be introduced together with a carrier gas (e.g., an inert gas). The additive gas may include a diluent gas, such as a reactive gas and an inert gas. The reactive gas and the diluent gas may be introduced into the reaction space mixedly or separately. The precursor may include two or more precursors, and the reactive gas may include two or more reactive gases. The precursor can be a gas that is chemisorbed onto a substrate and generally contains a metalloid or metallic element that forms a key structure of a matrix of a dielectric film. The reactive gas used for deposition can be a gas that, when excited to fix an atomic layer or monolayer onto the substrate, reacts with the precursor chemisorbed onto the substrate. The term "chemisorption" can refer to chemical saturation adsorption. Gases other than those used in this process (i.e., gases introduced without passing through the spray nozzle) can be used to seal the reaction space and may contain a sealing gas, such as an inert gas. In some embodiments, the term "film" can refer to a layer that extends continuously in a direction perpendicular to the thickness direction and is substantially free of pinholes, used to cover an entire target or a related surface, or it can refer to a layer that simply covers a target or a related surface. In some embodiments, the term "layer" can refer to a structure of any thickness formed on a surface, or it can be a synonym for a film or non-film structure. This membrane or layer may include a discrete single membrane or layer, or multiple membranes or layers having certain properties, and the boundaries between adjacent membranes or layers may be clear or unclear, and may be defined based on the physical, chemical and / or other properties, formation process or sequence and / or function or purpose of adjacent membranes or layers.

[0033] In this disclosure, the phrase "containing Si-N bonds" can refer to a structure having one or more Si-N bonds, having a main framework substantially formed by the Si-N bonds, and / or having a substituent substantially formed by the Si-N bonds. The silicon nitride layer can be a dielectric layer containing a Si-N bond, and may include a silicon nitride layer (SiN) and a silicon oxynitride layer (SiON).

[0034] In this disclosure, the expression "same material" should be interpreted as having the same main components (compositions). For example, when a first layer and a second layer are both silicon nitride layers and are formed of the same material, the first layer can be selected from the group consisting of silicon disitride (Si2N), silicon nitride (SiN), silicon tetranitride (Si3N4), and silicon trinitride (Si2N3), and the second layer can also be selected from the above group, but the quality of a particular film of the second layer may be different from the quality of the film of the first layer.

[0035] Furthermore, in this disclosure, depending on how an operational range can be determined based on a general work, any two variables can construct one operational range for such variables, and any indicated range may include or exclude certain capping sites. Additionally, the numerical value of any indicated variable may refer to an exact value or a rough estimate (whether or not they are indicated by the prefix "about"), and may include equivalent values, and may refer to averages, medians, representative values, multi-values, or the like.

[0036] Where conditions and / or structures are not specifically specified in this disclosure, those skilled in the art can readily provide such conditions and / or structures through conventional experimentation based on this disclosure. In all described embodiments, any component used in one embodiment may be replaced by any equivalent component, including those explicitly, necessary, or substantially described herein for the intended purpose. Furthermore, this disclosure is similarly applicable to apparatuses and methods.

[0037] Specific embodiments of the present disclosure will now be described with reference to the accompanying drawings. In the drawings, the shapes depicted may vary due to, for example, manufacturing techniques and / or tolerances. Therefore, embodiments of the present disclosure should not be construed as limited to the specific regional shapes depicted herein, but may include, for example, shape deviations caused by the manufacturing process.

[0038] Figure 1 is a flowchart of a substrate processing method according to several embodiments.

[0039] Referring to Figure 1, a substrate having a patterned structure is prepared. For example, a substrate may be loaded into a reaction space of a substrate processing apparatus. This substrate may be a semiconductor substrate and may include, for example, any one of: silicon, silicon-coated insulating layer, silicon-coated sapphire, germanium, silicon-germanium, and gallium arsenide.

[0040] This pattern structure is a non-planar structure and may be a stepped structure, including an upper surface, a lower surface, and a side surface connecting the upper and lower surfaces. For example, this pattern structure may include a plurality of protrusions defined by a plurality of grooves. This pattern structure may be used to form a reaction region or to form a gate pattern. For example, this pattern structure may include a first protrusion and a second protrusion, and each of the first protrusion and the second protrusion may include a gate electrode. When this pattern structure is used to fabricate a flash memory, each of the first protrusion and the second protrusion may further include a tunneling insulating layer.

[0041] In operation S110, when preparing this substrate, a first insulating layer can be formed on this patterned structure. During operation S110 of forming this insulating layer, a plasma-based thin film deposition process can be used. For example, at least one of plasma atomic layer deposition (PEALD), plasma chemical vapor deposition (PECVD), pulsed plasma chemical vapor deposition (PECVD), and cyclic pulsed plasma chemical vapor deposition can be used.

[0042] This protective layer can be configured to protect the patterned structure from free radicals formed during the plasma process, as detailed below. For example, this protective layer can be configured to protect the patterned structure from free radicals and fluoride ions supplied during the formation of the first end cap sites. Figure 5(a) shows an exemplary state in which a protective layer is formed on a patterned structure.

[0043] In some embodiments, this protective layer may include the composition of the gas supplied during operation S120 of forming these first end caps. For example, when nitrogen trifluoride (NF3) is used to form these first end caps, this protective layer may include a nitrogen element. For example, this protective layer may include silicon nitride.

[0044] After this protective layer is formed on this patterned structure, a procedure is performed to form a plurality of deposition inhibitor sites and a plurality of film-forming sites on this protective layer. First, in operation S120, in order to form these deposition inhibitor sites, a plurality of first end-capping sites may be formed on the surface of this protective layer. Subsequently, in operation S130, a plurality of second end-capping sites may be formed on the surface of this protective layer to form a plurality of film-forming sites.

[0045] In an alternative embodiment, the operation S110 of forming this protective layer may be omitted. Regardless of the presence or absence of this protective layer, the first end caps and the second end caps will be formed on the pattern structure, which includes a first protrusion and a second protrusion.

[0046] During operation S120 of forming these first end caps, a first gas may be supplied to form a plurality of end caps that can inhibit subsequent deposition on this protective layer. For example, these first end caps may be fluorine end caps, in which case a fluorine-containing gas, such as nitrogen trifluoride, may be supplied during the formation of these first end caps.

[0047] In some embodiments, the operation S120 of forming these first end cap sites can be performed under a first plasma condition, such that the first end cap sites can be uniformly formed on the protective layer. For example, the plasma frequency and process pressure can be set to be relatively low, such that the first end cap sites can be uniformly formed on all surfaces of the protective layer (top surface, bottom surface and multiple sides connecting the top and bottom surfaces).

[0048] In one embodiment, the first plasma conditions may include a first frequency (e.g., 430 kHz) and a first process pressure (1 to 5 Torr). That is, the first plasma conditions may be set such that the mean free path of the first gas supplied to the reaction space increases, and thus the first gas can reach the bottom surface of the protective layer. Figure 5(b) shows an exemplary state in which these first end caps are formed on the protective layer.

[0049] After forming these first end-capping sites, an operation S130 is performed to form a plurality of second end-capping sites different from these first end-capping sites, so as to form a plurality of film-forming sites on this protective layer. During the operation S130 of forming these second end-capping sites, a second gas may be supplied to form the plurality of end-capping sites, which can promote subsequent deposition on this protective layer. For example, these second end-capping sites may be hydrogen end-capping sites, and in this case, a hydrogen-containing gas, such as hydrogen (H2), may be supplied during the operation S130 of forming these second end-capping sites.

[0050] In some embodiments, the operation S130 of forming these second end cap sites can be performed under a second plasma condition, such that these second end cap sites can be selectively formed on the protective layer. For example, the plasma frequency and process pressure can be set to be relatively high, such that these second end cap sites can be selectively formed on the protective layer.

[0051] In one embodiment, the second plasma conditions may include a second frequency (e.g., 13.56 MHz) and a second process pressure (5 to 30 Torr). That is, the second plasma conditions may be set such that the mean free path of the second gas supplied to the reaction space is reduced, and thus the second gas remains surrounding the upper surface of the protective layer without reaching the bottom surface of the protective layer. Therefore, the ions and radicals of the second gas generated by applying the second plasma can react with a portion of the protective layer on the upper surface of the protective layer, and thus the first terminal sites surrounding the upper surface of the protective layer can be replaced by second terminal sites.

[0052] Figure 5(c) illustrates an exemplary state in which the first and second end caps are formed on the protective layer. By means of the operations S120 for forming the first end caps and S130 for forming the second end caps, the first end caps can be formed in a first portion of the protective layer, and the second end caps can be formed in a second portion of the protective layer. For example, the first portion with the first end caps can be located at the lower part of the pattern structure, while the second portion with the second end caps can be located at the upper part of the pattern structure (see Figure 2).

[0053] Subsequently, an operation S140 is performed to form a first layer on the first and second end-capping sites. The first and second end-capping sites may affect the formation of the first layer. The first end-capping sites can act as deposition inhibitor sites, and they can inhibit the formation of the first layer on a first portion of the protective layer (i.e., the portion where the first end-capping sites are formed). On the other hand, the second end-capping sites can promote the formation of the first layer on a second portion of the protective layer (i.e., the portion where the second end-capping sites are formed).

[0054] In some embodiments, the operation S140 of forming this first layer may include supplying a source gas and supplying a reactive gas. In an alternative embodiment, the supply of the source gas and the supply of the reactive gas may be included in a deposition cycle repeated multiple times. Furthermore, a purging operation may be performed after the supply of the source gas or after the supply of the reactive gas.

[0055] This source gas may include a material reactive with these second end-capping sites. Therefore, during the supply of this source gas, these second end-capping sites may be replaced with multiple third end-capping sites containing elements of this source gas. For example, this source gas may include a silicon precursor, and in this case, multiple Si end-capping sites (or Si-H end-capping sites) may be formed by supplying this source gas. In other words, these second end-capping sites (which are H end-capping sites) may be replaced with these third end-capping sites (which are Si end-capping sites or Si-H end-capping sites).

[0056] In an alternative embodiment, plasma may be applied during the supply of the source gas. The application of plasma may facilitate the replacement of the second end-cap sites with the third end-cap sites. In an alternative embodiment, the supply of a reactive purge gas may be stopped during the supply of the source gas. In another embodiment, the reactive purge gas may be supplied during the supply of the source gas, and the plasma conditions may be adjusted such that the reactive purge gas is not activated, while the source gas is activated.

[0057] This source gas may include materials that do not react with these first end-capping sites (or materials with low reactivity). Therefore, during the supply of this source gas, the formation of these third end-capping sites can be suppressed at these first end-capping sites. For example, when a silicon precursor is supplied as a source gas to form multiple Si-H end-capping sites on this protective layer, the formation of these Si-H end-capping sites can be suppressed at these first end-capping sites and promoted at these second end-capping sites. Figure 5(d) illustrates an exemplary state in which these Si-H end-capping sites are formed on this protective layer.

[0058] Subsequently, a reactive gas is supplied. This reactive gas may include a material that is reactive with the source gas. In some embodiments, the reactive gas may include a material that is reactive with the source gas under specific conditions (e.g., plasma application conditions). A first layer may be formed on this protective layer by supplying this reactive gas and chemically reacting it with a multilayer containing the source element (e.g., Si-H end-capping sites).

[0059] As described above, by forming these first end capping sites (as deposition inhibitor sites) in a lower space between the first protrusion and the second protrusion, a first layer (as an intermediate insulating layer) can be selectively formed. That is, due to these deposition inhibitor sites, the first layer can be selectively formed in an upper space between the first protrusion and the second protrusion. Figure 5(e) shows an exemplary state of selectively forming this first layer.

[0060] Subsequently, operation S150 is performed to form a second layer on the first layer. Operation S150 to form the second layer may include performing operations for forming the first layer (e.g., supplying the source gas and the reactive gas). Figure 5(f) shows an exemplary state in which the second layer is formed on the first layer.

[0061] By forming the first layer and the second layer on the patterned structure as described above, an intermediate insulating layer can be formed to cover the patterned structure. Furthermore, an air gap can be formed between the intermediate insulating layer and the patterned structure. Therefore, an air gap can be formed between the first protrusion and the second protrusion to prevent leakage current.

[0062] In some embodiments, these first end-capping sites can be used as deposition inhibitor sites, such that deposition on the portions where these first end-capping sites are formed can be suppressed, while simultaneously forming the intermediate insulating layer. Furthermore, even after the intermediate insulating layer is formed, the composition of these first end-capping sites can be retained in the air gap. For example, when these first end-capping sites are fluorine end-capping sites, the air gap can include a gas containing fluorine.

[0063] Specifically, nitrogen trifluoride can be used to form these first end-capping sites. In this case, a gas (e.g., nitrogen trifluoride and hydrogen fluoride) having nitrogen and / or fluorine elements as components of these first end-capping sites can be contained in this air gap. Furthermore, when this intermediate insulating layer comprises a silicon-containing material (e.g., silicon oxide and silicon nitride), a gas containing components of this intermediate insulating layer and components of these first end-capping sites can be contained in this air gap (e.g., silicon tetrafluoride).

[0064] Although Figure 1 shows and describes operations S140 and S150 for forming this second layer as separate operations for forming this intermediate insulating layer, operations S140 for forming this first layer and S150 for forming this second layer may be the same operations included in this deposition cycle. In another embodiment, the formation of this second layer may be omitted, and in this case, only the operation / cycle for forming this first layer may be performed to form this intermediate insulating layer.

[0065] In an alternative embodiment, between the operation S140 of forming this first layer and the operation S150 of forming this second layer, the operation of forming these first end caps and / or second end caps may be performed additionally. These additionally formed first / second end caps can help replenish end caps that disappear during repeated deposition cycles (especially multiple end caps used to suppress the formation of deposits below the gaps between protrusions).

[0066] Figure 2 shows a semiconductor device, which is manufactured using the substrate processing method shown in Figure 1.

[0067] As described above, and as shown in Figure 2, before forming a first layer, a deposition inhibitor site 220 is formed in a lower space LS between a first protrusion P1 and a second protrusion P2, thereby preventing the deposition of a thin film in this lower space LS during the formation of an intermediate insulating layer, allowing air gaps to be easily formed. Therefore, through this deposition inhibitor site 220, the intermediate insulating layer can be selectively formed in an upper space US between the first protrusion P1 and the second protrusion P2, and air gaps of sufficient size can be formed in this lower space LS between the first protrusion P1 and the second protrusion P2.

[0068] Furthermore, prior to the formation of this first layer, a film formation site 230 is formed in the upper space US between the first protrusion P1 and the second protrusion P2, thereby promoting the deposition of the thin film used to cover the upper space US during the formation of this intermediate insulating layer. Therefore, this intermediate insulating layer can be formed at high speed, thereby ensuring an air gap of sufficient size.

[0069] Figure 3 is a view of a substrate processing method according to several embodiments. The substrate processing method according to these embodiments may be a variation of the substrate processing method of the above embodiments. The embodiments will not be described repeatedly below.

[0070] Referring to FIG. For example, an operation S320 of forming these fluorine cap end sites can be performed by supplying a fluorine-containing gas under a first plasma condition of a first plasma frequency and a first process pressure.

[0071] A first cycle may be performed at least once during the formation of operation S320 of these fluorine capping sites. In this case, this first cycle may include supplying this fluorine-containing gas at a first plasma environment (i.e., this first plasma frequency and this first process pressure) and purging this fluorine-containing gas.

[0072] Thereafter, operation S330 forming multiple hydrogen capped end sites on this protective layer is performed. For example, the formation of these hydrogen capped end sites can be carried out by supplying a hydrogen-containing gas under a second plasma condition, wherein this second plasma condition includes a second plasma frequency above this first plasma frequency, and a second process pressure above this first process pressure.

[0073] A second cycle may be performed at least once during the formation of operation S330 of these fluorine capping sites. In this case, this second cycle may include supplying this hydrogen-containing gas in a first-second plasma environment and purging this hydrogen-containing gas.

[0074] Thereafter, the operation S340 of forming an intermediate layer insulation layer on this protective layer having these fluorine capped end sites and these hydrogen capped end sites is performed. One deposition cycle may be executed at least once during the operation S340 of forming this intermediate layer insulation layer. In this case, this deposition cycle may include: supplying a silicon-containing source gas to form multiple Si-H cap-end sites;

[0075] As described above, this source gas may include materials that will react with these hydrogen capping end sites but will not react with these fluorine capping end sites. Thus, the formation of these Si-H capping sites can be facilitated at these hydrogen capping sites and inhibited at these fluorine capping sites. Therefore, an intermediate layer of insulation can optionally be formed on this protective layer.

[0076] Subsequently, when this deposition cycle is repeated, operation S350 is performed to determine whether the formation of this intermediate insulating layer is complete. For example, it can be determined whether this deposition cycle has been repeated a specific number of times, and / or whether an air gap has been formed. When the formation of this intermediate insulating layer is not yet complete, this deposition cycle is repeated. However, when certain conditions are met, operation S320 for forming these fluorine end-capping sites and / or operation S330 for forming these hydrogen end-capping sites can be performed before repeating this deposition cycle. For example, when it is determined that there are no or insufficient fluorine end-capping sites, this deposition cycle can be performed after this first cycle and this second cycle.

[0077] In a gap fabrication method using a SiN thin film, a gap formation method can be considered, in which the upper part of the patterned structure is first closed using an atomic layer deposition method. However, when the SiN thin film is deposited in the lower part of the patterned structure before the top of this deposition is blocked, the size of the gap will decrease, and therefore, as the line width of the device decreases, problems will arise. For example, as shown in Figure 4, when the SiN thin film is deposited in the lower region of the patterned structure and the upper region is closed, a needle-shaped gap with a narrow width will be formed, thus degrading the dielectric properties.

[0078] Therefore, the purpose of this disclosure is to provide a method for suppressing deposition in the lower region of this pattern structure and to control the size of this air gap.

[0079] In this disclosure, the method for suppressing deposition and controlling the air gap size in the lower region of this pattern structure is intended to be achieved by combining deposition inhibitors, plasma and process pressure conditions.

[0080] Figure 5 illustrates views of substrate processing methods according to various embodiments. The substrate processing methods according to these embodiments may be variations of the substrate processing methods described above. The embodiments will not be described repeatedly below.

[0081] See Figure 5. Each operation is described in detail below.

[0082] 1) Step 1(a): Forming a protective layer. In this step, a protective layer 2 is formed on a patterned structure 1. For example, a SiN film is uniformly deposited on this patterned structure 1 by plasma-enhanced atomic layer deposition (PEALD). This step is to form a protective layer to protect this patterned structure from the invasion of activated fluorine (F) ions and free radicals in the next step, as detailed below. The thickness of this protective layer 2 is 30 angstroms.

[0083] 2) Step 2(b): A deposition inhibitor is supplied and multiple deposition inhibitor sites are formed. In this step, a deposition inhibitor is supplied onto this protective layer 2 formed in the first step. Fluorine was supplied as a deposition inhibitor to form multiple fluorine capping sites on this protective layer 2 . For example, radio frequency (RF) power is used to activate nitrogen trifluoride (NF3) to generate fluorine radicals. This step is performed under the conditions of low frequency RF power and low process pressure to enable these fluorine radicals to reach the bottom surface of this pattern structure, so that the average free diameter of these fluorine radicals can be extended, and these fluorine radicals can reach the bottom surface of this pattern structure. These fluorine capping sites were also formed on a protective layer on the underside of this patterned structure. In this step, this deposited inhibitor may be supplied (e.g.) in the form of a pulse at least once.

[0084] 3) Step 3(c): Multiple film-forming sites are formed. In this step, the plurality of film-forming sites is formed on a one-pattern structure that has been formed with multiple fluorine-containing deposition inhibitor sites (inhibitor sites or fluorine capping sites). In this step, activated hydrogen radicals are supplied. These hydrogen radicals react with fluorine to convert these fluorine capping end sites into multiple hydrogen capping end sites. These hydrogen capping end sites served as membrane-forming sites. More specifically, in a subsequent step, these hydrogen capping sites react with a gas containing a source element, and they are converted into multiple source element containing-terminated sites. In this step, multiple hydrogen capping end sites are formed in the upper part of this patterned structure by performing under conditions of high frequency RF power and high process pressure, the average free path of these hydrogen radicals is shortened, and multiple hydrogen capping end sites are formed in the upper region of this patterned structure. In this step, hydrogen may be supplied at least once in pulse form.

[0085] 4) Step 4(d): Supply a source of gas (precursor). In this step, a source of gas is supplied. For example, as this source gas, one of the raw material gases containing silicon, amine silane or iodosilane gas is supplied. Since these hydrogen capping sites (which are bonding sites) are formed on this patterned structure in step 3, this source gas reacts with these hydrogen capping end sites on this pattern structure to form multiple source-containing element capping sites. For example, when a source gas containing silicon elements is supplied, Si-H capping sites can be formed. However, the source-containing element capping sites were not formed due to the presence of these fluorine capping sites (which are deposition inhibitor sites) in the lower region of this patterned structure.

[0086] 5) Step 5(e): Supply a reactive gas. In this step, a reactive gas that reacts with a source gas is supplied to form a thin film through a chemical reaction with a source element. For example, by supplying a Si source gas in step 4 and then supplying a nitrogen reactive gas activated by radio frequency power in step 5, a silicon nitride film can be formed by chemically reacting with these source element end-capping sites. Alternatively, a silicon oxide film can be formed by supplying an activated oxygen gas. However, since these fluorine end-capping sites (which are deposition inhibitor sites) still exist in the lower region of this patterned structure, the source element end-capping sites are not formed.

[0087] 6) Step 6(f): Forming an air gap. By repeating steps 4 and 5 (first repetition), an air gap is formed in which the upper part of the pattern is closed and the interior of the pattern is empty. As can be seen from Figure 5(f), the width G of this air gap is greater than the width of the air gap in Figure 4. This is because, as shown in Figures 5(b) to (e), the film deposition inhibitor site is located in the lower region of a pattern structure and therefore does not react with a source gas and does not form a film. Therefore, this disclosure has the technical effect of maintaining the maximum width of the air gap by supplying a deposition inhibitor to this pattern structure.

[0088] During the first repetition period (first repetition) of Figure 5, the source gas and the reactive gas are supplied multiple times. However, due to the repeated supply of the source gas and the reactive gas, especially the repeated and continuous supply of active species, the deposition inhibitor sites in the lower region of the pattern structure may decrease. Therefore, after the first repetition period is performed a certain number of times (first repetition), a deposition inhibitor is supplied to the pattern structure again (second repetition). As shown in Figure 5, after repeating Figures 5(d) to 5(e) a certain number of times, the steps of Figures 5(b) to 5(e) are repeated (second repetition). Therefore, a technical effect of this disclosure is that it is possible to maintain a constant number of deposition inhibitor sites in the lower region of the pattern structure until the air gap is formed, and to prevent the width of the air gap from decreasing.

[0089] Figure 6 illustrates a process sequence view according to the embodiment of Figure 5. Figure 6 shows a process of depositing a SiN thin film on a patterned structure while simultaneously forming a gap using a plasma-assisted atomic layer deposition method. Sections t1 to t4 in Figure 6 correspond to a protective layer deposition in step 1(a) of Figure 5, and sections t5 to t6 correspond to the supply of a deposition inhibitor and the formation of deposition inhibitor sites in step 2(b) of Figure 5. Sections t7 to t8 in Figure 6 correspond to the supply of hydrogen and the formation of film formation sites in step 3(c) of Figure 5, while sections t9 to t12 correspond to the supply of a Si source gas in step 4(d) of Figure 5 and the supply of a nitrogen radical in Figure 5(e). Sections t9 to t12 in Figure 6 are repeated multiple times (first repetition), and subsequently sections t5 to t12 are repeated (second repetition), thereby maintaining these deposition inhibitor sites in the lower region of the patterned structure and preventing the gap width from decreasing. In Figure 6, nitrogen gas (N2) is a reactive purge gas that reacts chemically with a silicon source gas when activated by radio frequency power, or it is an inert gas and is used as both a silicon source carrier gas and a purge gas.

[0090] Table 1 below shows the RF frequency and process stress conditions for each step in Figures 5 to 6.

[0091] Table 1 Step 1 Step 2 Step 3 Steps 4 and 5 Radio frequency High (13.56 megahertz) Low (430 kHz) High (13.56 megahertz) High (13.56 megahertz) Process pressure High (5 to 30 torrents) Low (1 to 5 torts) High (5 to 30 torrents) High (5 to 30 torrents)

[0092] Figure 7 shows the thickness of a SiN film at each location in a patterned structure based on the number of cycles during a first repetition period (first repetition) in Figures 5 to 6.

[0093] Referring to Figure 7, up to 100 cycles, the SiN film deposited at the bottom of this patterned structure has a thickness of 1.6 Å, the SiN film deposited at the bottom of the side of this patterned structure has a thickness of 2.1 Å, the SiN film deposited at the top of this patterned structure has a thickness of 10.9 Å, and the SiN film deposited at the top of the side of this patterned structure has a thickness of 10.4 Å. Therefore, it can be seen that film deposition in the lower region is sufficiently suppressed within an acceptable range. However, after 170 cycles, the SiN film deposited at the bottom of this patterned structure has a thickness of 11 Å, the SiN film deposited at the bottom of the side of this patterned structure has a thickness of 13 Å, the SiN film deposited at the top of this patterned structure has a thickness of 14 Å, and the SiN film deposited at the top of the side of this patterned structure has a thickness of 16 Å. Therefore, it can be seen that the width of the air gap in the lower region is greatly reduced, as in the example in Figure 4. Therefore, according to the embodiments in Figures 5 and 6, it can be seen that the maximum value of the preferred first repetition period is approximately 100 cycles. In other words, it is preferable to perform 100 cycles during this first repetition period (first repetition) and then perform a second repetition period (second repetition) to supply a deposition inhibition gas (inhibitor). Therefore, a technical advantage of this disclosure is that these deposition inhibition sites in the lower region of this pattern structure can be continuously maintained.

[0094] Table 2 below shows the deposition conditions of a SiN thin film according to an embodiment. As a Si source gas, a Si-containing gas (e.g., at least one source gas selected from aminosilane, iodosilane, dichlorosilane (DCS), and monochlorosilane (MCS)) is supplied. This source gas is supplied to a reactor using nitrogen as the carrier gas. This nitrogen gas is a reactive purge gas and reacts chemically with the source gas when activated by radio frequency power; otherwise, it is used as a source carrier gas or a purge gas. As a reactive gas, a nitrogen-containing gas (e.g., at least one selected from nitrogen, nitrogen oxides, nitrogen dioxide, and ammonia) can be supplied. Regarding the radio frequency power, a high-frequency power of 13.56 MHz and a low-frequency power of 470 kHz are applied differentially in steps.

[0095] Table 2 Step 1 Steps 4 to 5 Step 2 (Inhibition step) Step 3 (H2 flow step) Gas flow rate (sccm) Silicon Source (Carrier N2) 1,000-4,000 - - N2 2,000-10,000 2,000-10,000 2,000-10,000 NF3 - 100-2,000 - H2 - - 100-1,000 Processing time (Second) Source supply 0.1-1.0 - - Source sweep 0.1-1.0 - - reactant supply (Radio Frequency Plasma) 0.5-5.0 - - reactant purging 0.1-1.0 0.1-1.0 0.1-1..0 NF3 supply (Radio Frequency Plasma) - 0.5-30 - NF3 Blow - 0.1-1.0 - H2 supply (Radio Frequency Plasma) - - 0.5-5.0 H2 purging - - 0.1-1.0 RF power (W) 13.56 megahertz 100 to 1,000 watts - 100 to 1,000 watts 430 kHz - 100 to 1,000 watts - Process pressure (Torque) 5 to 30 torrents 1 to 5 torrents 5 to 30 torrents Temperature (°C) 350~550 350~550 350~550

[0096] As described above, according to several embodiments, when forming an air gap in a patterned structure, a deposition inhibitor can be supplied by controlling a radio frequency and process pressure, thereby forming an air gap structure in the lower region of the patterned structure. In particular, by supplying the deposition inhibitor, the reduction in the air gap width can be minimized, and the air gap structure can be maintained. Furthermore, by applying a first repetition period and a second repetition period, the deposition inhibitor sites can be continuously maintained in the lower region of the patterned structure, and the air gap structure can be stably maintained.

[0097] It should be understood that the embodiments described herein are for illustrative purposes only and not for limiting purposes. The description of multiple features or styles in each embodiment should generally be considered as other similar features or styles that can be used in other embodiments. Although one or more embodiments have been described with reference to drawings, those skilled in the art will understand that various changes in form and detail may be made therein without departing from the spirit and scope of this disclosure as defined by the following claims. [Simplified Explanation of the Diagram]

[0026] The above and other features, characteristics and advantages of certain embodiments of this disclosure will become clearer from the following description and with reference to the accompanying drawings, in which: Figure 1 is a flowchart of a substrate processing method according to several embodiments; Figure 2 is a view showing a semiconductor device fabricated using a substrate processing method according to several embodiments; Figure 3 is a view showing a substrate processing method according to several embodiments; Figure 4 is a view illustrating a method for forming an air gap, wherein the upper part of the patterned structure is first closed; Figure 5 is a view illustrating a substrate processing method according to several embodiments; Figure 6 is a view illustrating a processing sequence according to the embodiment of Figure 5; and Figure 7 is a view illustrating the thickness of the SiN film at each position in the patterned structure according to the number of cycles during a first repetition period from Figures 5 to 6.

Claims

1. A substrate processing method, comprising: A protective layer is formed on a patterned structure; a plurality of first end caps are formed on the patterned structure, the patterned structure including a first protrusion and a second protrusion; a plurality of second end caps, different from the first end caps, are formed on the patterned structure on which the first end caps are formed; and a first layer is formed on the first end caps and the second end caps, wherein the first end caps and the second end caps are formed on one surface of the protective layer.

2. The substrate processing method of claim 1, wherein the first end caps are located in a first portion of a protective layer in a lower part of a pattern structure, and the second end caps are located in a second portion of a protective layer in an upper part of a pattern structure.

3. The substrate processing method of claim 2, wherein the formation of the first layer on the first portion is suppressed by the first end capping sites and on the second portion is promoted by the second end capping sites.

4. The substrate processing method of claim 1, wherein the first end capping sites are fluorine end capping sites.

5. The substrate processing method of claim 1, wherein the second end capping sites are hydrogen end capping sites.

6. The substrate processing method of claim 1, wherein the formation of the first layer includes: Supply a source gas that is reactive with the second end capping sites; and supply a reactive gas.

7. The substrate processing method of claim 6, wherein the source gas includes a silicon precursor, and the Si-H end caps are formed by supplying the source gas.

8. The substrate processing method of claim 7, wherein the formation of Si-H end cap sites is suppressed at the first end cap sites and promoted at the second end cap sites.

9. The substrate processing method of claim 1, wherein the formation of the first end cap sites is performed under plasma conditions at a first frequency, and the formation of the second end cap sites is performed under plasma conditions at a second frequency greater than the first frequency.

10. The substrate processing method of claim 1, wherein the formation of the first end caps is performed under a first process pressure, and the formation of the second end caps is performed under a second process pressure greater than the first process pressure.

11. The substrate processing method of claim 1 further includes forming a second layer on the first layer.

12. The substrate processing method of claim 11 further includes forming at least one end point on the first layer between forming the first layer and forming the second layer.

13. The substrate processing method as described in claim 1, wherein, During the formation of these first end caps, a first cycle comprising supplying a fluorine-containing gas is performed at least once.

14. The substrate processing method of claim 13, wherein the fluorine-containing gas includes NF3.

15. The substrate processing method as described in claim 13, wherein, During the formation of these second end caps, a second cycle including the supply of one of the hydrogen-containing gases is performed at least once.

16. The substrate processing method of claim 15, wherein the hydrogen-containing gas includes H2.

17. The substrate processing method of claim 1, wherein at least a portion of an intermediate insulating layer is formed to cover the patterned structure, an air gap is formed between the first protrusion and the second protrusion, and the intermediate insulating layer includes the first layer.

18. The substrate processing method of claim 17, wherein the air gap includes a gas containing fluorine.

19. A substrate processing method, comprising: A protective layer is formed on a patterned structure, the patterned structure including a first protrusion and a second protrusion; A fluorine-containing gas is supplied under first plasma conditions at a first frequency and a first process pressure to form a plurality of fluorine end-cap sites on the protective layer; the fluorine-containing gas is purged; a hydrogen-containing gas is supplied under second plasma conditions at a second frequency higher than the first frequency and a second process pressure higher than the first process pressure to form a plurality of hydrogen end-cap sites on the protective layer; the hydrogen-containing gas is purged; a silicon-source gas is supplied to form a plurality of Si-H end-cap sites, wherein the formation of the Si-H end-cap sites is promoted at the hydrogen end-cap sites and inhibited at the fluorine end-cap sites; the silicon-source gas is purged; an intermediate insulating layer is formed on the protective layer by supplying a reactive gas that is reactive with the Si-H end-cap sites; and the reactive gas is purged.

20. A substrate processing method, comprising: A plurality of deposition inhibitor sites are formed in the lower space between a first convex portion and a second convex portion; An intermediate insulating layer is formed on the first protrusion and the second protrusion, wherein the intermediate insulating layer is selectively formed in an upper space between the first protrusion and the second protrusion by means of the deposition inhibitor sites, and thus an air gap is formed between the first protrusion and the second protrusion.

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