Method and apparatus for filling gaps and devices implemented by the method

Abstract

Provided are a method and apparatus for filling a gap using an atomic layer deposition (ALD) method, and a device implemented by the method. The method includes forming a first reaction inhibition layer by adsorbing a reaction inhibitor onto the sidewalls of the gap, forming a first precursor layer by adsorbing a first reactant onto the bottom of the gap and the sidewalls of the gap around the bottom of the gap, and forming a first atomic layer at the bottom of the gap and on the sidewalls of the gap around the bottom of the gap. The reaction inhibitor includes a precursor material that does not react with the second reactant. The first reaction inhibition layer may have a density gradient in which the density of the reaction inhibitor decreases toward the bottom of the gap. Forming the first atomic layer includes adsorbing the second reactant onto the first precursor layer.

Description

Technical Field

[0001] The present disclosure relates to methods and / or apparatus for filling gaps using atomic layer deposition (ALD). Background Art

[0002] Atomic layer deposition (ALD) has been used as a process for filling gaps (such as trenches) formed on a substrate. In ALD, a surface reaction is utilized. Therefore, when a gap is filled using ALD, a filling layer can be formed with a uniform thickness on the surface around the gap, thereby reducing and / or minimizing the formation of voids. However, when the gap has a high aspect ratio, the size of the entrance of the gap may become smaller than the size of the interior of the gap. Therefore, even when ALD is used, voids may be formed. Summary of the Invention

[0003] One or more embodiments provide methods and / or apparatuses for filling gaps using atomic layer deposition (ALD) and devices implemented by the methods.

[0004] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the embodiments presented herein.

[0005] According to an embodiment, a method for filling a gap formed on a substrate by using atomic layer deposition (ALD) is provided. The method includes forming a first reaction inhibition layer by adsorbing a reaction inhibitor onto the sidewalls of the gap, the reaction inhibitor including a precursor material that does not react with a second reactant, the first reaction inhibition layer having a density gradient in which the density of the reaction inhibitor decreases toward the bottom of the gap; forming a first precursor layer by adsorbing the first reactant onto the bottom of the gap and the sidewalls of the gap around the bottom of the gap; and forming a first atomic layer on the bottom of the gap and the sidewalls of the gap around the bottom of the gap. Forming the first atomic layer includes adsorbing the second reactant onto the first precursor layer.

[0006] In some embodiments, the density gradient of the first reaction inhibition layer can be determined according to the following equation:

[0007]

[0008] Where l represents the depth of the sidewall of the gap where the reaction inhibitor is adsorbed (nm), w represents the width of the gap (nm), P represents the partial pressure of the reaction inhibitor in the reaction chamber (Pa), t represents the exposure time of the reaction inhibitor (s), and S represents the saturation dose (≒2.5×10 18 molecules·m), m represents the molecular weight of the reaction inhibitor (kg), and k represents the Boltzmann constant (1.38×10 -23J / K, and T represents the temperature in the reaction chamber (K).

[0009] In some embodiments, the reaction inhibitor may be oxidized by O 3 or O 2 plasma. The reaction inhibitor may be converted into the material of the first atomic layer via O 3 or O 2 plasma treatment.

[0010] In some embodiments, the reaction inhibitor may not react with H2O or O2.

[0011] In some embodiments, the reaction inhibitor may include a central metal and an organic ligand.

[0012] In some embodiments, the organic ligand may include a cyclopentadienyl (Cp) ligand or a pentamethylcyclopentadienyl (Cp*) ligand.

[0013] In some embodiments, the reaction inhibitor may include (Me2N)2SiMe2, TiCp*(OMe)3, Ti(CpMe)(O i Pr)3, Ti(CpMe)(NMe2)3, ZrCp(NMe2)3, ZrCp2Cl2, Zr(Cp2CMe2)Me2, Zr(Cp2CMe2)Me(OMe), HfCp(NMe2)3 or Hf(CpMe)(NMe2)3.

[0014] In some embodiments, the reaction inhibitor may have the same central metal as the metal of the first reactant.

[0015] In some embodiments, the first reactant may include TiCl4, Ti(O i Pr)4, Ti(NMe2)4, Ti(NMeEt)4, Ti(NEt2)4, ZrCl4, Zr(NMe2)4, Zr(O t Bu)4, ZrCp2Me2, Zr(MeCp)2(OMe)Me, HfCl4, Hf(NMe2)4, Hf(NEtMe)4, Hf(NEt2)4, HfCp2Me2 or Hf(MeCp)2(OMe)Me.

[0016] In some embodiments, the second reactant may include H2O or O2.

[0017] In some embodiments, the average density of the reaction suppressant may increase as the partial pressure of the reaction suppressant in the reaction chamber increases.

[0018] In some embodiments, the adsorption of the reaction inhibitor may be repeatedly performed for a plurality of cycles, and the average density of the reaction inhibitor may increase as the number of cycles increases.

[0019] In some embodiments, the method may further include forming a first filling layer by repeatedly performing the forming of the first precursor layer and the forming of the first atomic layer in a plurality of cycles.

[0020] In some embodiments, the density of the reaction inhibitor may decrease toward the bottom of the gap, such that the first filling layer may be formed in a bottom-up direction from the bottom of the gap.

[0021] In some embodiments, the first filling layer may be formed to have a shape that varies according to an average density of the reaction inhibitor.

[0022] In some embodiments, the first filling layer may have a shape in which the first filling layer is formed in a bottom-up direction from the bottom of the gap.

[0023] In some embodiments, the first filling layer may have a shape in which the first filling layer is formed from a bottom of the gap and a sidewall of the gap around the bottom of the gap.

[0024] In some embodiments, the gap-filling process time may be adjusted according to the shape formed by the first filling layer.

[0025] In some embodiments, the method may further include: forming a second reaction inhibition layer on the side walls of the gap after forming the first filling layer; forming a second precursor layer on the upper surface of the first filling layer and the side walls of the gap around the upper surface of the first filling layer; and forming a second atomic layer on the upper surface of the first filling layer and the side walls of the gap around the upper surface of the first filling layer.

[0026] In some embodiments, the method may further include forming a second filling layer in a bottom-up direction from an upper surface of the first filling layer by repeatedly performing the forming of the second precursor layer and the forming of the second atomic layer in a plurality of cycles.

[0027] According to an embodiment, a device may include a structure defining a gap having a high aspect ratio, and a filling layer in the gap, wherein the filling layer may be formed by the above method.

[0028] In some embodiments, the gap can have a nanometer-sized width and an aspect ratio equal to or greater than about 10.

[0029] The device may include a metalens including a structure defining a gap. The structure defining the gap may be a nanostructure in which the gap is formed. A filling layer may fill the gap and have a higher refractive index than the nanostructure.

[0030] In some embodiments, the nanostructure may include SiO 2 and the filling layer may include TiO 2 .

[0031] In some embodiments, the structure defining the gap may be an interconnect structure including an insulating layer in which the gap is formed, and a filling layer may fill the gap. The filling layer may include a conductive material.

[0032] In some embodiments, the structure defining the gap may include a three-dimensional (3D) NAND flash memory device including a memory cell, the gap penetrating the memory cell, and a filling layer filling the gap. The filling layer may include an insulating material.

[0033] According to an embodiment, a method for filling a gap formed on a substrate by using atomic layer deposition (ALD) is provided. The method includes: forming a first filling layer by sequentially adsorbing a first reactant and a second reactant onto the sidewalls and bottom of the gap; forming a first reaction inhibition layer by adsorbing a reaction inhibitor onto the first filling layer formed on the sidewalls of the gap, the reaction inhibitor including a precursor material that does not react with the second reactant, the first reaction inhibition layer having a density gradient in which the density of the reaction inhibitor decreases toward the bottom of the gap; forming a first precursor layer, forming the first precursor layer including adsorbing the first reactant onto the first filling layer formed on and around the bottom of the gap; and forming a first atomic layer on the first filling layer formed on and around the bottom of the gap, forming the first atomic layer including adsorbing the second reactant onto the first precursor layer.

[0034] In some embodiments, the method may further include forming a second filling layer in a bottom-up direction from an upper surface of the first filling layer, wherein forming the second filling layer may include repeatedly performing forming the first precursor layer and forming the first atomic layer in a plurality of cycles.

[0035] After forming the second filling layer, the method may further include: forming a second reaction-inhibiting layer on the first filling layer formed on the sidewalls of the gap; forming a second precursor layer on an upper surface of the second filling layer and on the first filling layer around the upper surface of the second filling layer; forming a second atomic layer on the upper surface of the second filling layer and on the first filling layer around the upper surface of the second filling layer; and forming a third filling layer in a bottom-up direction from the upper surface of the second filling layer. Forming the third filling layer may include repeatedly performing forming the second precursor layer and forming the second atomic layer in a plurality of cycles.

[0036] According to an embodiment, a device may include a structure defining a gap having a high aspect ratio, and a filling layer in the gap. The filling layer may be formed in the gap using the above-described method.

[0037] According to an embodiment, an atomic layer deposition (ALD) device includes: a substrate including a plurality of processing areas; and a reactant supply device on the substrate, the reactant supply device being configured to fill the gap formed on each of the plurality of processing areas. The reactant supply device may include at least one first supply unit, at least one second supply unit, and at least one third supply unit. The at least one first supply unit may be configured to form a reaction inhibition layer on the sidewall of the gap by supplying a reaction inhibitor to the substrate. The at least one second supply unit may be configured to form a precursor layer on the bottom of the gap and the sidewall around the bottom of the gap of the gap by supplying a first reactant to the substrate. The at least one third supply unit may be configured to form an atomic layer on the sidewall around the bottom of the gap and the bottom of the gap of the gap by supplying a second reactant to the substrate. The reaction inhibitor may include a precursor material that does not react with the second reactant.

[0038] In some embodiments, the ALD apparatus may further include a purge unit between adjacent supply units among the at least one first supply unit, the at least one second supply unit, and the at least one third supply unit.

[0039] In some embodiments, the reaction inhibition layer may have a density gradient in which the density of the reaction inhibitor decreases toward the bottom of the gap.

[0040] In some embodiments, the density gradient of the reaction inhibition layer may be determined according to the rotation speed of the substrate and the number of revolutions of the substrate.

[0041] According to an embodiment, a method for filling a gap formed on a structure using atomic layer deposition (ALD) is provided. The structure defines the gap and includes a first reaction inhibition layer, the first reaction inhibition layer including a reaction inhibitor adsorbed onto the sidewall of the gap. The method includes forming a first precursor layer by adsorbing a first reactant onto a first exposed area of the gap, and forming a first atomic layer on the first exposed area of the gap by adsorbing a second reactant onto the first precursor layer. The first exposed area of the gap includes the bottom of the gap and a first portion of the sidewall of the gap around the bottom of the gap. The first reaction inhibition layer defines the first exposed area of the gap based on the first reaction inhibition layer having a density gradient in which the density of the reaction inhibitor decreases toward the bottom of the gap, so that the first reaction inhibition layer exposes the first portion of the sidewall of the gap and the bottom of the gap. The reaction inhibitor includes a precursor material. The second reactant is a material that does not react with the precursor material in the reaction inhibitor.

[0042] In some embodiments, the reaction inhibitor may be oxidized by O 3 or O 2 plasma.

[0043] In some embodiments, the method may further include removing the reaction inhibitor by converting the reaction inhibitor into a material of the first atomic layer via an O 3 or O 2 plasma treatment.

[0044] In some embodiments, the reaction inhibitor may include a central metal and an organic ligand.

[0045] In some embodiments, the second reactant may include H2O or O2.

[0046] According to an embodiment, a device may include a filling layer formed using the above method. The filling layer may be provided in a gap. The gap may have a high aspect ratio. The gap may have a nanometer-sized width and an aspect ratio equal to or greater than about 10.

[0047] In some embodiments, the device can include a metalens including a structure having a gap formed therein. The refractive index of the filling layer can be higher than the refractive index of a region of the structure surrounding the gap.

[0048] In some embodiments, in the device, the structure in which the gap is formed may be an insulating layer, and the filling layer in the gap may include a conductive material.

[0049] In some embodiments, in the device, the structure in which the gap is formed may include a memory cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The above and other aspects, features and effects of certain embodiments of the present disclosure will become more apparent from the following description in conjunction with the accompanying drawings, in which:

[0051] Figures 1 to 10C is a view for describing a method of filling a gap according to an example embodiment;

[0052] Figure 11 An example of a reaction suppression layer formed in a gap filling method is shown;

[0053] Figure 12 An example of a first filling layer formed in a method of filling a gap is shown;

[0054] Figures 13 to 20 is a view for describing a method of filling a gap according to another example embodiment;

[0055] Figure 21 is a schematic plan view of an atomic layer deposition (ALD) apparatus according to an example embodiment;

[0056] Figure 22 yes Figure 21 Along with the ALD equipment Figure 21 A cross-sectional view taken along line II';

[0057] Figure 23 yes Figure 21 Along with the ALD equipment Figure 21 A cross-sectional view taken along line II-II';

[0058] Figures 24A to 24C shows a metalens according to an example embodiment;

[0059] Figure 25 Augmented reality (AR) glasses are shown as an example of a near-eye display device;

[0060] Figure 26 An example of a dynamic random access memory (DRAM) device including an interconnect structure according to an example embodiment is shown;

[0061] Figure 27 An example of a three-dimensional (3D) NAND flash memory device according to example embodiments is shown; and

[0062] Figure 28 is a block diagram of an electronic device according to an embodiment. DETAILED DESCRIPTION

[0063] Reference will now be made in detail to the embodiments, examples of which are shown in the accompanying drawings, wherein the same reference numerals always refer to the same elements. In this regard, the proposed embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Therefore, aspects will be explained below by describing only the embodiments with reference to the accompanying drawings. As used herein, the term "and / or" includes any and all combinations of one or more of the relevant enumerated items. Expressions such as "at least one of...", when following a list of elements, modify the entire list of elements without modifying the individual elements in the list. For example, "at least one of A, B, and C," "at least one of A, B, or C," "at least one of A, B, C, or a combination thereof," and "at least one of A, B, C, and a combination thereof" may be interpreted as covering any one of the following combinations: A; B; A and B; A and C; B and C; and A, B, and C.

[0064] When the terms "about" or "substantially" are used in conjunction with a numerical value in this specification, it is intended that the relevant numerical value includes a manufacturing or operating tolerance (e.g., ±10%) around the stated numerical value. In addition, when the terms "substantially" and "substantially" are used in conjunction with a geometric shape, it is intended that the exactness of the geometric shape is not required, but the latitude of the shape is within the scope of the present disclosure. In addition, regardless of whether a numerical value or shape is modified as "about" or "substantially," it will be understood that these numerical values and shapes should be interpreted as including a manufacturing or operating tolerance (e.g., ±10%) around the stated numerical value or shape.

[0065] Hereinafter, example embodiments will be described in detail with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same elements, and the sizes of the elements may be exaggerated for clarity and ease of explanation. The embodiments described below are only non-limiting examples, and various modifications may be made based on the embodiments.

[0066] Hereinafter, it will be understood that when an element is referred to as being "on" or "over" another element, the element may be directly above or below the other element and directly to the left or right of the other element, or intervening elements may exist therebetween. As used herein, the singular terms "a" and "an" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when a part "includes" or "comprising" an element, unless otherwise specified, the part may also include other elements and does not exclude other elements.

[0067] The term "the" and other equivalent determinants can correspond to either a singular or plural referent.

[0068] Unless the order of operations included in the method is particularly described or there is a description to the contrary, the operations can be performed in a suitable order.

[0069] All examples and exemplary terms are used only to describe the present disclosure in detail, and the present disclosure is not limited to the examples and exemplary terms unless they are defined in the claims.

[0070] Recently, efficient planar metalenses with high-precision and high-aspect-ratio nanostructures have been developed. These highly efficient planar metalenses can be widely used in various fields, such as laser-based microscopy, imaging, and spectroscopy. The gap-filling method described below can be used as a fabrication technique for metasurface devices requiring high-precision and high-aspect-ratio nanostructures.

[0071] As semiconductor devices become highly integrated, the planar dimensions of discrete devices or interconnections gradually become smaller. In contrast, the thickness of the layers included in the semiconductor devices gradually becomes larger. In addition, with the development of multilayer technology for three-dimensionally arranging or connecting discrete devices of semiconductor devices, large step heights may appear on the surface of the process substrate and deep gaps with a high aspect ratio may be formed according to each processing operation. When an interlayer insulating layer is formed on a process substrate having a large step height and a deep gap with a high aspect ratio, voids and the like may be easily formed. The method for filling the gaps to be described below can be applied to the manufacture of semiconductor devices as a technology for filling deep gaps with a high aspect ratio formed in a process substrate.

[0072] In addition, the method of filling the gap described below can be used in various fields where the formation of thin layers is important, such as: optical sensors including optoelectronic devices, oxygen sensors, optical measuring instruments, etc., catalysts including hydrogen photocatalysts, catalysts in artificial biotechnology, biomedical materials and devices, etc.

[0073] Figures 1 to 10C is a view for describing a method of filling the gap 150 according to example embodiments.

[0074] In the method of filling the gap 150, according to an example embodiment, first, by allowing a reaction inhibitor to adsorb onto the sidewall 150a of the gap 150, first to third reaction inhibiting layers 111, 112, and 113 may be formed. Next, by allowing a first reactant as a precursor material and a second reactant as a co-reactant of the first reactant to adsorb onto and around the bottom 150b of the gap 150 through an atomic layer deposition (ALD) process, a first atomic layer 131 may be formed. Thereafter, the first reactant and the second reactant may be repeatedly adsorbed for a plurality of cycles to form first to third filling layers 141, 142, and 143 in a bottom-up direction from the bottom 150b of the gap 150. Hereinafter, the method of filling the gap according to an example embodiment will be described in detail.

[0075] Reference Figure 1 , a structure including a gap 150 (such as a substrate 100) may be disposed in a reaction chamber (not shown) of an ALD apparatus. Here, the gap 150 in the substrate 100 may have a certain width w and a certain depth h.

[0076] The gap 150 may have a high aspect ratio, for example, of about 10 or more (e.g., 10 to 20, 10 to 50, but not limited thereto), but is not limited thereto. Here, the aspect ratio refers to the ratio h / w of the depth h of the gap 150 to the width w of the gap 150. The gap 150 may have a width w of, for example, about several tens of nanometers. As a detailed example, the gap 150 may have a width w of about 20 nm to about 100 nm. However, this is merely an example, and the width w of the gap 150 may be modified in various ways.

[0077] like Figure 2 As shown, a structure in which a material layer 105 having a gap 150 is formed on a substrate 100' can be provided in a reaction chamber. For example, the substrate 100' can include silicon, and the material layer 105 can include silicon oxide. In this case, an etch stop layer (not shown) including HfO2 can be further provided between the substrate 100' and the material layer 105.

[0078] Reference Figure 3, a first reaction inhibiting layer 111 may be formed on the sidewall 150a of the gap 150. The first reaction inhibiting layer 111 may be formed by adsorbing a reaction inhibitor onto the sidewall 150a of the gap 150. Here, the reaction inhibitor may include a precursor material that does not react with a second reactant that serves as a co-reactant in the ALD process performed after forming the first reaction inhibiting layer 111.

[0079] The first reaction-inhibiting layer 111 may have a density gradient in which the density of the reaction inhibitor decreases from the entrance of the gap 150 toward the bottom 150b of the gap 150. Therefore, the bottom 150b of the gap 150 and the surrounding of the bottom 150b of the gap 150 may not be covered by the first reaction-inhibiting layer 111 and may be exposed.

[0080] Hereinafter, the material of the reaction suppressor will be described.

[0081] According to this embodiment, the reaction inhibitor may have basic properties similar to those of a previous ALD precursor that is compatible with the ALD process. Specifically, the reaction inhibitor may have excellent reactivity for a short exposure time, good volatility for easy vaporization, and good thermal adsorption relative to the substrate. Furthermore, the reaction inhibitor may be thermally stable, produce no reactive volatile byproducts, and be high-purity, economically viable, easy to handle, and environmentally friendly to be suitable for mass production. Therefore, the reaction inhibitor may be selected from previously known ALD precursors, but is not limited thereto.

[0082] In addition, reaction inhibitors can also include the following two characteristics.

[0083] First, the reaction suppressor can be turned into a thin layer only by being oxidized by a strong co-reactant (such as O2 plasma or O3). Second, the reaction suppressor may not react with H2O or O2 (e.g., H2O vapor or O2 vapor) used as a co-reactant in the ALD process performed after forming the first reaction suppressing layer 111. As described below, additional characteristics of the reaction suppressor can be confirmed by measuring the contact angle or thickness change after performing the sequential ALD process.

[0084] Hereinafter, Ti(OMe)4 and TiCp*(OMe)3, which are used as ALD precursors for forming a thin layer of TiO2, will be compared. Here, Me corresponds to CH3 and Cp* corresponds to pentamethylcyclopentadienyl.

[0085] When a Ti(OMe)4 precursor is used, the ALD process using H2O as a co-reactant at a temperature of about 300°C or less can be performed at a temperature of about 0.4 to about 100°C. A thin TiO2 layer can be grown using a growth per cycle (GPC) process with a cycle of 100 cycles. However, when a TiCp*(OMe)3 precursor is used, a thin TiO2 layer may not be formed in an ALD process using H2O as a co-reactant. A thin TiO2 layer can be formed using only O2 plasma or O3 as a co-reactant.

[0086] The TiCp*(OMe)3 precursor can be strongly adsorbed onto TiO2 through H bonds. However, due to the steric hindrance of the Cp* ligand located thereon, it is difficult to form a new Ti-O bond. In addition, due to its hydrophobicity, the Cp* ligand may be difficult to oxidize by reacting with H2O in the ALD process after forming the first reaction inhibition layer 111. However, the Cp* ligand can be oxidized by O2 plasma or O3, which are stronger co-reactants than H2O, to form a thin layer. In addition, the TiCp*(OMe)3 precursor may not be adsorbed onto the pure TiO2 surface.

[0087] Therefore, it can be confirmed that the TiCp*(OMe)3 precursor can have the characteristics of a reaction inhibitor in the process of forming a TiO2 thin layer using the ALD process. In detail, when the TiCp*(OMe)3 precursor is used as a reaction inhibitor and the ALD process is performed by using an ALD precursor for forming a TiO2 thin layer, for example, tetrakis(dimethylamino)titanium (TDMAT) (which can be oxidized by H2O), the reaction inhibitor, and H2O may not react with each other in the area coated with the reaction inhibitor, and thus a TiO2 thin layer may not be formed, and TDMAT and H2O may react with each other in the area not coated with the reaction inhibitor, and thus a TiO2 thin layer may be formed. In addition, because the TiCp*(OMe)3 precursor is not adsorbed on the surface of TiO2, even if the reaction inhibitor is repeatedly applied, the TiCp*(OMe)3 precursor may not be trapped in the TiO2 thin layer as an impurity.

[0088] As described above, the reaction inhibitor may include a precursor material that does not react with H 2 O or O 2 among ALD precursors, wherein H 2 O or O 2 may be used as a co-reactant in the ALD process performed after forming the first reaction inhibiting layer 111 .

[0089] The reaction inhibitor may include a precursor material comprising a central metal and an organic ligand. The organic ligand may include a cyclopentadienyl (Cp) ligand or a pentamethylcyclopentadienyl (Cp*) ligand. In this case, when the reaction inhibitor includes a precursor material having the same central metal as the ALD precursor of the material to be filled, impurity entrapment due to the reaction inhibitor may be reduced and / or minimized. For example, as described above, when a TiCp*(OMe)3 precursor is used as the reaction inhibitor and TDMAT is used as the ALD precursor for forming a TiO2 thin layer, impurity entrapment due to the reaction inhibitor may be reduced and / or minimized.

[0090] Table 1 below shows examples of materials that may be used as reaction inhibitors when forming a thin layer of TiO 2 , ZrO 2 , and / or HfO 2 (eg, a gap-filling material).

[0091] [Table 1]

[0092]

[0093] Referring to Table 1, it is confirmed that the reaction suppressor may have the same central metal as the ALD precursor of the thin layer to be formed. The reaction suppressor described in Table 1 may have low reactivity with H2O and thus may not be oxidized.

[0094] When the reaction suppressor is applied at the atomic layer level and the amount of trapped impurities does not significantly affect device performance, the reaction suppressor may not necessarily have the same central metal as the ALD precursor of the thin layer to be formed. In this case, as described with respect to Table 2, various precursor materials that do not react with co-reactants such as HO or O can be used as the reaction suppressor. The materials shown in Table 2 are merely examples; other precursor materials may also be used.

[0095] [Table 2]

[0096]

[0097] The Cp-based precursors used as reaction inhibitors described in Table 2 may not be reactive with H2O or O2 due to steric hindrance and hydrophobicity, and may form a thin layer by separating the ligands only with a strong co-reactant such as O2 plasma or O3. In addition, even when the reaction inhibitor comprises only one atomic layer, it may be difficult for the reaction inhibitor to adsorb onto other precursors due to steric hindrance, and thus, the reaction inhibitor may have barrier properties.

[0098] When selecting the material of the reaction inhibitor, the next thing to consider is the operation of controlling the density of the reaction inhibitor adsorbed onto the sidewalls of the gap. In the ALD process for the bottom-up gap filling method, the first reaction inhibition layer 111 may have to be coated on the wall surface of the gap 150 to have a density gradient in which the density of the reaction inhibitor decreases toward the bottom 150b of the gap 150. In detail, the density of the reaction inhibitor may have to increase around the entrance of the gap 150 and gradually decrease along the sidewalls 150a of the gap 150 toward the bottom 150b of the gap 150, so that the reaction inhibitor may not be coated (and / or may be less coated) on the bottom 150b of the gap 150. By adjusting the exposure amount of the reaction inhibitor, the density gradient of the first reaction inhibition layer 111 can be obtained.

[0099] In detail, the density gradient of the first reaction inhibition layer 111 may be determined according to Equation 1 reflecting stoichiometry and diffusion behavior of molecules.

[0100]

[0101] Here, l represents the depth (nm) of the sidewall 150a of the gap 150 to the position where the reaction inhibitor is adsorbed, w represents the width (nm) of the gap 150, P represents the partial pressure (Pa) of the reaction inhibitor in the reaction chamber, t represents the exposure time (s) of the reaction inhibitor, and S represents the saturation dose (≒2.5×10 18 molecules·m), m represents the molecular mass of the reaction inhibitor kg, and k represents the Boltzmann constant 1.38×10 -23 J / K, T represents the temperature in the reaction chamber in K.

[0102] In (Equation 1), the depth l of the position on which the reaction inhibitor is adsorbed from the sidewall 150a of the gap 150 can be determined by adjusting the exposure amount of the reaction inhibitor (i.e., the product of the partial pressure and the exposure time of the reaction inhibitor). In this case, the density of the reaction inhibitor can increase around the entrance of the gap 150 and can gradually decrease along the sidewall 150a of the gap 150 toward the bottom 150b of the gap 150.

[0103] The average density of the reaction inhibitor can be adjusted. Here, the average density of the reaction inhibitor refers to the compactness of the reaction inhibitor adsorbed onto the sidewall 150a of the gap 150. When the average density of the reaction inhibitor is high, the reaction inhibitor can be formed more densely on the sidewall 150a of the gap 150 than when the average density of the reaction inhibitor is low.

[0104] The average density of the reaction inhibitor can be adjusted, for example, by using the partial pressure Pa of the reaction inhibitor in the reaction chamber. Specifically, as the partial pressure Pa of the reaction inhibitor increases, the average density of the reaction inhibitor can increase. In addition, the adsorption of the reaction inhibitor can be repeatedly performed for a plurality of cycles. In this case, as the number of cycles increases, the average density of the reaction inhibitor adsorbed onto the sidewall 150a of the gap 150 can increase.

[0105] As described below, the first filling layer ( Figure 6 141 and Figure 12 141 ') can be formed to have a varying shape. Figure 3 The average density of the reaction inhibitor is shown compared to Figure 11 The average density of the reaction inhibitor is relatively high. Figure 3 ,and Figure 11Compared to the case of FIG. 1 , a relatively large amount of the reaction inhibitor may exist on the sidewall 150 a of the gap 150 around the bottom 150 b of the gap 150 .

[0106] After forming the first reaction inhibiting layer 111 on the sidewall 150a of the gap 150, a purge process for discharging materials remaining in the reaction chamber to the outside may be performed. The purge process may be performed using, for example, N2 gas, but is not limited thereto.

[0107] Reference Figure 4 , a first precursor layer 121 may be formed on and around the bottom 150b of the gap 150. The first precursor layer 121 may be formed by allowing the first reactant to be adsorbed onto and around the bottom 150b of the gap 150. As described above, the first reaction-inhibiting layer 111 may be formed to have a density gradient in which the density of the reaction inhibitor decreases toward the bottom 150b of the gap 150. Therefore, the bottom 150b of the gap 150 and the sidewalls 150a surrounding it may not be coated with the first reaction-inhibiting layer 111 and may be exposed. The first reactant may be adsorbed onto the exposed bottom 150b of the gap 150 and the exposed sidewalls 150a surrounding the bottom 150b to form the first precursor layer 121.

[0108] The first reactant may include a precursor material of the thin layer to be formed. For example, the first reactant may include TiCl4, Ti(O i Pr)4, Ti(NMe2)4, Ti(NMeEt)4, Ti(NEt2)4, ZrCl4, Zr(NMe2)4, Zr(O t The first reactant may be a crystalline solid or a crystalline solid. The first reactant may be a crystalline solid or a crystalline solid. The first reactant may be a crystalline solid or a crystalline solid. The first reactant may be a crystalline solid or a crystalline solid.

[0109] Reference Figure 5 , a first atomic layer 131 may be formed on and around the bottom 150b of the gap 150. The first atomic layer 131 may be formed by adsorbing a second reactant onto the first precursor layer 121. The second reactant may be a co-reactant and may include, for example, H2O or O2. The first atomic layer 131 may include, but is not limited to, oxide, nitride, or metal.

[0110] As described above, the reaction inhibitor may include a precursor material that does not react with the second reactant. Therefore, the second reactant introduced into the gap 150 may not react with the first reaction-inhibiting layer 111 and may react with the first reactant of the first precursor layer 121 to form the first atomic layer 131. As described above, the first atomic layer 131 may be formed only in an area of the wall surface of the gap 150 that is not coated with the first reaction-inhibiting layer 111, that is, on the bottom 150b of the gap 150 and the sidewall 150a around the bottom 150b. After forming the first atomic layer 131, a purge process may be performed.

[0111] Reference Figure 6 By repeatedly performing adsorption of the first reactant and adsorption of the second reactant for about tens to hundreds of cycles (e.g., about 30 to 600 cycles), the first filling layer 141 can be formed in the lower portion of the gap 150 to have a certain height. Here, the cycle may include adsorption of the first reactant, purging, adsorption of the second reactant, and purging. Figure 3 As shown, when the average density of the reaction suppressant adsorbed onto the sidewalls 150 a of the gap 150 is relatively high, the first filling layer 141 may be formed in a bottom-up direction from the bottom 150 b of the gap 150. The reaction suppressant may remain on the sidewalls 150 a of the gap 150, and the sidewalls 150 a may contact the first filling layer 141.

[0112] By repeatedly performing adsorption of the first reactant and the second reactant, the amount of the first reaction inhibiting layer 111 on the sidewall 150 a of the gap 150 may be gradually reduced, and thus, the barrier property of the first reaction inhibiting layer 111 may be reduced.

[0113] Reference Figure 7 , a second reaction-inhibiting layer 112 may be formed on the sidewall 150a of the gap 150. The second reaction-inhibiting layer 112 may be formed by adsorbing the reaction inhibitor onto the sidewall 150a of the gap 150. Here, the second reaction-inhibiting layer 112 may have a density gradient in which the density of the reaction inhibitor decreases from the entrance of the gap 150 toward the first filling layer 141. Therefore, the upper surface of the first filling layer 141 and the sidewall 150a of the gap 150 around the first filling layer 141 may not be covered by the second reaction-inhibiting layer 112 and may be exposed.

[0114] The reaction suppressor may include a precursor material that does not react with the second reactant such as H2O or O2. The material and density adjustment of the reaction suppressor are described above, so the description thereof will be omitted. After forming the second reaction suppressing layer 112, a purge process may be performed.

[0115] Reference Figure 8A, a second precursor layer 122 may be formed on the upper surface of the first filling layer 141 and the sidewalls 150a of the gap 150 around the first filling layer 141. The second precursor layer may be formed by adsorbing a first reactant onto the upper surface of the first filling layer 141 exposed by the second reaction inhibition layer 112 and the sidewalls 150a of the gap 150 around the first filling layer 141. Here, as described above, the first reactant may include a precursor material of the thin layer to be formed. After the second precursor layer is formed, a purge process may be performed.

[0116] Next, refer to Figure 8B , a second atomic layer 132 may be formed on the upper surface of the first filler layer 141 and the sidewalls 150a of the gap 150 around the first filler layer 141. The second atomic layer may be formed by adsorbing a second reactant onto the second precursor layer. The second reactant may be a co-reactant and may include, for example, H2O or O2. After forming the second precursor layer, a purge process may be performed.

[0117] Next, refer to Figure 8C By repeatedly performing the adsorption of the first reactant and the second reactant for approximately tens to hundreds of cycles, the second filling layer 142 can be formed to a certain height above the first filling layer 141. Here, the second filling layer 142 can be formed from the upper surface of the first filling layer 141 in a bottom-up direction. As the adsorption of the first reactant and the second reactant are repeatedly performed, the amount of the second reaction-inhibiting layer 112 on the sidewall 150a of the gap 150 can gradually decrease.

[0118] Reference Figure 9 , a third reaction-suppressing layer 113 may be formed on the sidewalls 150a of the gap 150. The third reaction-suppressing layer 113 may be formed by adsorbing a reaction inhibitor onto the sidewalls 150a of the gap 150. Here, the third reaction-suppressing layer 113 may have a density gradient in which the density of the reaction inhibitor decreases from the entrance of the gap 150 toward the second filling layer 142. Therefore, the upper surface of the second filling layer 142 and the sidewalls 150a of the gap 150 surrounding the second filling layer 142 may not be covered by the third reaction-suppressing layer 113 and may be exposed. After forming the third reaction-suppressing layer 113, a purge process may be performed.

[0119] Reference Figure 10A, a third precursor layer 123 may be formed on the upper surface of the second filling layer 142 and the sidewalls 150a of the gap 150 around the second filling layer 142. The third precursor layer 123 may be formed by adsorbing the first reactant onto the upper surface of the second filling layer 142 exposed by the third reaction inhibition layer 113 and the sidewalls 150a of the gap 150 around the second filling layer 142. After forming the third precursor layer, a purge process may be performed. Next, referring to Figure 10B By allowing the second reactant to be adsorbed onto the third precursor layer, a third atomic layer 133 may be formed. Thereafter, after the third atomic layer 133 is formed, a purge process may be performed.

[0120] Reference Figure 10C By repeatedly performing the adsorption of the first reactant and the adsorption of the second reactant for about tens to hundreds of cycles, the third filling layer 143 can be formed to have a certain height above the second filling layer 142. Here, the third filling layer 143 can be formed from the upper surface of the second filling layer 142 in a bottom-up direction.

[0121] Therefore, since the first to third filling layers 141 to 143 are sequentially formed in the gap 150, a bottom-up gap filling method can be implemented in which a filling material is filled in the gap 150 in a bottom-up direction from the bottom 150 b of the gap 150. In the above-mentioned gap filling process, the reaction inhibitor remaining in the gap 150 can be removed by being converted into the filling material through O3 treatment or O2 plasma treatment.

[0122] Although Figures 1 to 10C An example is shown in which the gap 150 is filled with the first to third filling layers 141 , 142 , and 143 , but the inventive concept is not limited thereto. The number of filling layers filling the gap 150 may be variously modified.

[0123] Figure 11 An example of the reaction inhibiting layer 111 ′ formed on the sidewall 150 a of the gap 150 is shown. Figure 11 The average density of the reaction inhibitor included in the reaction inhibition layer 111 ′ is shown compared with Figure 3 The average density of the reaction inhibitor is relatively low.

[0124] Reference Figure 11, when the average density of the reaction inhibitor is relatively low, a relatively small amount of the reaction inhibitor may be present on the sidewall 150a around the bottom 150b of the gap 150. In this case, the first filling layer 141' may be formed not only on the bottom 150b of the gap 150 but also on the sidewall 150a around the bottom 150b of the gap 150. Therefore, the first filling layer 141' may be formed to have a shape in which the central portion of the upper surface of the first filling layer 141' is convex downward, as shown in FIG. Figure 12 In other words, Figure 12 As shown, the upper surface of the first filling layer 141' can be concave. In this process, the speed of forming the first filling layer 141' can be higher than Figure 6 The speed at which the first filling layer 141 is formed.

[0125] As described above, the shape of the first filling layer 141' formed in the gap 150 can be changed according to the average density of the reaction inhibitor adsorbed onto the sidewalls 150a of the gap 150, and the gap-filling process time can be adjusted according to the shape of the first filling layer 141' formed. Specifically, when the average density of the reaction inhibitor adsorbed onto the sidewalls 150a of the gap 150 decreases, the speed of forming the first filling layer 141' can be increased, and thus, the gap-filling process time can be reduced.

[0126] According to this embodiment, a precursor material that does not react with a co-reactant (such as H2O or O2) to be used in a sequential ALD process can be used as a reaction inhibitor, and a density gradient can be formed in which the density of the reaction inhibitor decreases from the entrance of the gap 150 toward the bottom 150b of the gap 150, thereby achieving bottom-up gap filling, thereby filling the gap 150 with a filling material in a bottom-up direction starting from the bottom 150b of the gap 150.

[0127] Furthermore, the reaction suppressor may include a precursor material having the same central metal as a precursor used in a sequential ALD process to form a thin layer, thereby limiting and / or preventing the entrapment of impurities.

[0128] In the following, we will confirm the reaction inhibitor TiCp based on the experiment. * Adsorption, reactivity and barrier properties of (OMe)3.

[0129] <Experimental Example 1> Adsorption Characteristics of Reaction Inhibitors

[0130] Using TiCp * (OMe)3 was used as a reaction inhibitor, and a SiO2 substrate was used as a substrate on which adsorption was performed. * (OMe)3 ALD process. In this process, TiCp* The temperature of the tank of (OMe) 3 was about 70°C, and the temperature of the reaction chamber was maintained at 180°C.

[0131] The cyclic process of adsorption of the reaction inhibitor may include exposing the SiO2 substrate to the reaction inhibitor for a certain period of time to allow the reaction inhibitor to be adsorbed onto the SiO2 substrate, and removing the remaining reaction inhibitor that has not participated in the reaction through a purge process. Here, sample cases in which the reaction inhibitor exposure time corresponds to 5 seconds (s), 10 seconds, 15 seconds, and 20 seconds are described.

[0132] By measuring the contact angle, it is possible to determine whether the adsorption of TiCp*(OMe)3 on the SiO2 substrate has been performed. Here, the contact angle represents the water contact angle (WCA). WCA is the angle formed by the tangent to the water droplet at the gas-liquid-solid interface. When no additional surface treatment is performed on the SiO2 substrate, the SiO2 substrate can have a hydrophilic surface. Therefore, the SiO2 substrate can have a relatively high surface energy and thus can have a relatively small contact angle. When the reaction inhibitor is not adsorbed onto the SiO2 substrate, the contact angle on the SiO2 substrate is measured to be 49.2 degrees. By increasing the exposure time of the reaction inhibitor, the contact angle increases. When the exposure time of the reaction inhibitor is 15s, the contact angle has a maximum value of 99.5 degrees. In this case, it can be determined that the reaction inhibitor is completely adsorbed onto the SiO2 substrate. At the same time, when the exposure time of the reaction inhibitor is increased to greater than 15s, the contact angle decreases slightly. In the case of the sample in which the exposure time of the reaction inhibitor is 15s, after 40 hours, the contact angle remains at 96.9 degrees, indicating that the TiCp*(OMe)3 is completely adsorbed on the SiO2 substrate. * (OMe)3 has adsorption stability.

[0133] <Experimental Example 2> Reactivity of Reaction Inhibitors

[0134] ALD process was performed to confirm the TiCp * Here, by using TiCp * (OMe) 3 as a Ti precursor and H 2 O as a co-reactant were used to perform an ALD process at a temperature of 180° C. When a thickness change was detected after performing the ALD process, it was shown that the TiCp * The reaction between (OMe)3 and H2O forms a thin TiO2 layer.

[0135] Among them, TiCp * The exposure time of (OMe)3 is 1s, 5s, 10s, 15s and 20s. *As a result of comparing the exposure time of (OMe)3 with that of the bare substrate, almost no thickness change was detected. This aspect indicates that no TiO2 thin layer was formed, and thus confirms that TiCp * (OMe)3 has no reactivity with H2O. Therefore, when using TiCp * When (OMe) 3 is used as a reaction inhibitor, the reaction inhibitor has no reactivity with H 2 O.

[0136] <Experimental Example 3> Barrier Properties of Reaction Inhibitors

[0137] First, an ALD process was performed at 180°C using TDMAT as a Ti precursor on a Si substrate and H₂O as a co-reactant. The cycle conditions of the ALD process used here included TDMAT (1 s) – N₂ purge (60 s) – H₂O (30 s) – N₂ purge (60 s). The ALD process was performed for 250 cycles, and a TiO₂ thin layer having a thickness of 10 nm was formed on the Si substrate. The contact angle measured on the TiO₂ thin layer was 59.6 degrees.

[0138] Next, a thin layer of TiO2 was exposed to TiCp * (OMe)315s with TiCp as reaction inhibitor * A first sample was prepared by coating a thin TiO layer formed by the aforementioned ALD process with (OMe)3. The contact angle measured after the reaction inhibitor application was 99.1 degrees, confirming a change in the surface state. Furthermore, a second sample was prepared in which the TiO layer formed by the aforementioned ALD process was not treated.

[0139] Thereafter, the above-described ALD process was performed again on each of the first sample and the second sample. In the second sample in which the reaction inhibitor was not applied, a TiO2 thin layer having a thickness of 10 nm was additionally deposited, and the contact angle was measured to be substantially the same as the contact angle of the previously formed TiO2 thin layer. In the first sample in which the reaction inhibitor was applied, the contact angle was measured to be 93.5 degrees, which was greater than the contact angle of the TiO2 thin layer. That is, in the first sample in which the reaction inhibitor was applied, no TiO2 thin layer was formed and the reaction inhibitor remained applied. Therefore, it was shown that when TiCp was used, the TiO2 thin layer was not formed. * When (OMe) 3 is used as a reaction inhibitor, the reaction inhibitor has excellent barrier properties.

[0140] Figures 13 to 20 2 is a diagram for describing a method of filling a gap according to another exemplary embodiment. In addition to pre-forming a first filling layer ( Figure 14Except for the process of 241), the method of filling the gap according to this embodiment is the same as the method of filling the gap according to the above embodiment.

[0141] Reference Figure 13 , the substrate 200 including the gap 250 may be disposed in a reaction chamber (not shown) of an ALD apparatus. Here, the gap 250 may have a high aspect ratio of about 10 or more, but is not limited thereto.

[0142] Reference Figure 14 The first filling layer 241 can be formed to have a certain thickness on the sidewalls 250a and the bottom 250b of the gap 250 by using an ALD process. First, a precursor layer (not shown) can be formed by adsorbing a first reactant on the sidewalls 250a and the bottom 250b of the gap 250. The first reactant may include a precursor material of the thin layer to be formed. For example, the first reactant may include TiCl4, Ti(O i Pr)4, Ti(NMe2)4, Ti(NMeEt)4, Ti(NEt2)4, ZrCl4, Zr(NMe2)4, Zr(O t The first reactant may be Bu)4, ZrCp2Me2, Zr(MeCp)2(OMe)Me, HfCl4, Hf(NMe2)4, Hf(NEtMe)4, Hf(NEt2)4, HfCp2Me2, or Hf(MeCp)2(OMe)Me. However, the first reactant is not limited thereto. After forming the first precursor layer, a purge process may be performed.

[0143] Thereafter, an atomic layer (not shown) may be formed by adsorbing the second reactant onto the precursor layer. The atomic layer may be formed via a reaction between the first reactant and the second reactant. The second reactant may be a co-reactant and may include, for example, H2O or O2. In addition, a purge process may be performed after the atomic layer is formed.

[0144] By repeatedly performing the above-described adsorption of the first reactant and the adsorption of the second reactant for tens to hundreds of cycles, the first filling layer 241 can be formed to a certain thickness on the sidewalls 250a and the bottom 250b of the gap 250. Here, one cycle may include adsorption of the first reactant, purging, adsorption of the second reactant, and purging. The first filling layer 241 may include, for example, oxide, nitride, or metal, but is not limited thereto.

[0145] Reference Figure 15, a first reaction-inhibiting layer 211 may be formed on the first filling layer 241 formed on the sidewall 250a of the gap 250. The first reaction-inhibiting layer 211 may be formed by adsorbing a reaction inhibitor onto the first filling layer 241 formed on the sidewall 250a of the gap 250. Here, the reaction inhibitor may include a precursor material that does not react with the second reactant as a co-reactant. The materials of the reaction inhibitor are described above, and therefore will not be described again.

[0146] The first reaction suppression layer 211 may have a density gradient in which the density of the reaction suppressant decreases from the entrance of the gap 250 toward the bottom 250b of the gap 250. Here, the density gradient of the first reaction suppression layer 211 may be determined according to the above-mentioned equation 1. Therefore, the first filling layer 241 formed on the bottom 250b of the gap 250 and around the bottom 250b of the gap 250 may not be covered by the first reaction suppression layer 211 and may be exposed. The density gradient of the first reaction suppression layer 211 has been described above, and therefore, its description will be omitted. After the first reaction suppression layer 211 is formed, a purge process for discharging the materials remaining in the reaction chamber to the outside may be performed.

[0147] Reference Figure 16 , a first precursor layer 221 may be formed on and around the first filling layer 241 formed on the bottom 250b of the gap 250. The first precursor layer 221 may be formed by allowing a first reactant to be adsorbed onto and around the first filling layer 241 formed on the bottom 250b of the gap 250. The first filling layer 241 formed on the bottom 250b of the gap 250 and the area around the first filling layer 241 may not be covered by the first reaction-inhibiting layer 211 and may be exposed. The first reactant may be adsorbed onto the first filling layer 241 exposed on the bottom 250b of the gap 250 and the exposed area around the first filling layer 241 to form the first precursor layer 221.

[0148] The first reactant may include a precursor material of the thin layer to be formed. For example, the first reactant may include TiCl4, Ti(O i Pr)4, Ti(NMe2)4, Ti(NMeEt)4, Ti(NEt2)4, ZrCl4, Zr(NMe2)4, Zr(O t After forming the first precursor layer 221, a purge process may be performed.

[0149] Reference Figure 17, a first atomic layer 231 can be formed on and around the first filling layer 241 formed on the bottom 250b of the gap 250. The first atomic layer 231 can be formed by allowing a second reactant to be adsorbed onto and around the first filling layer 241 formed on the bottom 250b of the gap 250. The second reactant can be a co-reactant and can include, for example, H2O or O2. The first atomic layer 231 can include, but is not limited to, oxide, nitride, or metal. After forming the first atomic layer 231, a purge process can be performed.

[0150] Reference Figure 18 By repeatedly performing the above-described adsorption of the first reactant and the adsorption of the second reactant for approximately tens to hundreds of cycles, the second filling layer 242 can be formed on the first filling layer 241 to have a certain height. Here, one cycle may include adsorption of the first reactant, purging, adsorption of the second reactant, and purging. The second filling layer 242 can be formed from the upper surface of the first filling layer 241 in a bottom-up direction. As the adsorption of the first reactant and the adsorption of the second reactant are repeatedly performed, the amount of the first reaction-inhibiting layer 211 on the sidewall 250a of the gap 250 can gradually decrease.

[0151] Reference Figure 19 A second reaction-inhibiting layer (not shown) may be formed on the first filling layer 241 formed on the sidewall 250a of the gap 250. The second reaction-inhibiting layer may be formed by adsorbing a reaction inhibitor onto the first filling layer 241 formed on the sidewall 250a of the gap 250. After forming the second reaction-inhibiting layer, a purge process may be performed.

[0152] Next, after forming a second precursor layer (not shown) by allowing the first reactant to be adsorbed onto and around the upper surface of the second filling layer 242, a purge process may be performed. In addition, after forming a second atomic layer (not shown) by allowing the second reactant to be adsorbed onto the second precursor layer, a purge process may be performed.

[0153] By repeatedly performing the adsorption of the first reactant and the second reactant for approximately tens to hundreds of cycles, the third filling layer 243 can be formed on the second filling layer 242 to have a certain height. Here, the third filling layer 243 can be formed from the upper surface of the second filling layer 242 in a bottom-up direction. As the adsorption of the first reactant and the second reactant are repeatedly performed, the amount of the second reaction-inhibiting layer formed on the first filling layer 241 on the sidewall 250a of the gap 250 can gradually decrease.

[0154] Reference Figure 20A third reaction-inhibiting layer (not shown) may be formed on the first filling layer 241 formed on the sidewall 250a of the gap 250. The third reaction-inhibiting layer may be formed by adsorbing a reaction inhibitor onto the first filling layer 241 formed on the sidewall 250a of the gap 250. After forming the third reaction-inhibiting layer, a purge process may be performed.

[0155] Next, after forming a third precursor layer (not shown) by allowing the first reactant to be adsorbed onto and around the upper surface of the third filling layer 243, a purge process may be performed. In addition, after forming a third atomic layer (not shown) by allowing the second reactant to be adsorbed onto the third precursor layer, a purge process may be performed.

[0156] By repeatedly performing the adsorption of the first reactant and the adsorption of the second reactant for about tens to hundreds of cycles, the fourth filling layer 244 can be formed to a certain height on the third filling layer 243. Here, the fourth filling layer 244 can be formed from the upper surface of the third filling layer 243 in a bottom-up direction.

[0157] According to the present embodiment, the first filling layer 241 may be pre-formed to have a certain thickness on the sidewalls 250a and the bottom 250b of the gap 250, and then the second to fourth filling layers 242 to 244 may be sequentially formed in the gap 250. Therefore, the processing time required for the gap filling process can be reduced.

[0158] Hereinafter, an ALD apparatus for performing the method of filling a gap according to the above-described embodiment at high speed will be described.

[0159] Figure 21 is a schematic plan view of an ALD apparatus 500 according to an example embodiment. Figure 22 yes Figure 21 The ALD device 500 is Figure 21 A cross-sectional view taken along line II' of Figure 23 yes Figure 21 The ALD device 500 is Figure 21 A cross-sectional view taken along line II-II'.

[0160] Reference Figure 21 , the ALD apparatus 500 may include a substrate 300 and a reactant supply device 400 on the substrate 300. A plurality of processing regions 310 may be provided on the substrate 300, and at least one gap (not shown) to be filled may be formed on each processing region 310. For example, the plurality of processing regions 310 may include a plurality of wafers provided on the substrate 300. The plurality of processing regions 310 may be arranged to have a circular shape that externally surrounds the substrate 300. Figure 21An example is shown in which eight processing regions 310 are provided on the substrate 300. However, the number of processing regions provided on the substrate 300 is not limited thereto and may be variously modified.

[0161] Reactant supply device 400 can be configured to fill the gap by supplying reactant on the processing area 310 of substrate 300, and can include at least one first supply unit 411, at least one second supply unit 421 and at least one third supply unit 422. The first supply unit 411, the second supply unit 421 and the third supply unit 422 can each include one or more tanks for storing reactants, and the reactant supply device can include a pipeline (for example, a pipeline) and a pumping system for supplying reactants and / or reaction inhibitors to the processing area 310 of substrate 300. Substrate 300 and reactant supply device 400 can be provided as relatively rotatable. Generally, reactant supply device 400 can be fixed, and substrate 300 can be rotatable. For example, substrate 300 can be on a platform and fixed with, for example, an electrostatic chuck, a fixture, and a motor can be configured to rotate the platform. However, the present disclosure is not limited thereto. Substrate 300 can be fixed on a platform, and reactant supply device 400 can be rotatable. For example, a motor can be configured to rotate the reactant supply device.

[0162] At least one first supply unit 411, at least one second supply unit 421, and at least one third supply unit 422 may be arranged to have a circular shape along the plurality of process regions 310. In addition, each purge unit 450 may be provided between the first to third supply units 411, 421, and 422. The purge unit 450 may include a container (e.g., a tank) for storing a purge gas (e.g., N2, argon) and a pumping system for supplying the purge gas to a region between the process regions 310 of the ALD apparatus 500. Figure 21 An example is shown in which the reactant supply device 400 includes two first supply units 411, three second supply units 421, and three third supply units 422, and the purge unit 450 is provided between the first to third supply units 411, 421, and 422. However, the present disclosure is not limited thereto, and the number of the first to third supply units 411, 421, and 422 may be variously modified.

[0163] Each processing region 310 on the substrate 300 can be supplied with a reaction inhibitor, a first reactant, and a second reactant via rotation from the first to third supply units 411, 421, and 422. Therefore, as described above, a gap formed in the processing region 310 can be filled in a bottom-up direction.

[0164] Figure 22The supply of reaction suppressants to each processing region 310 is shown. Figure 22 The first supply unit 411 can supply a reaction inhibitor to each processing area 310 of the rotating substrate 300, so that a reaction inhibition layer can be formed on the sidewall of the gap. The reaction inhibitor may include, for example, a precursor material that does not react with H2O or O2. This aspect has been described above, and therefore, its description will be omitted.

[0165] Figure 22 An example is shown in which the two first supply units 411 supply the reaction suppressor. However, the present disclosure is not limited thereto, and only one of the two first supply units 411 may supply the reaction suppressor.

[0166] The purge unit 450 may be provided around each of the first supply units 411. The purge unit 450 may supply a purge gas such as N2 gas between the process regions 310 while the first supply unit 411 supplies the reaction inhibitor to the process region 310.

[0167] The reaction-inhibiting layer formed on the sidewalls of the gap may have a density gradient, as described above, where the density of the reaction inhibitor decreases toward the bottom of the gap. To this end, it may be necessary to control the exposure time of the processing area 310 to the reaction inhibitor. The exposure time can be controlled by adjusting the rotation speed and number of revolutions of the substrate 300.

[0168] Figure 23 FIG. 3 shows that after the reaction inhibition layer is formed, the first reactant R1 and the second reactant R2 are supplied to each processing region 310. Figure 23 , the second supply unit 421 can supply the first reactant R1 to each processing area 310, thereby forming a precursor layer at the bottom of the gap and around the bottom of the gap. The first reactant R1 may include a precursor material of the thin layer to be formed. In addition, the third supply unit 422 can supply the second reactant R2 to each processing area 310. Here, the second reactant R2 may be a co-reactant and may include, for example, H2O or O2. Therefore, the second reactant R2 can react with the precursor layer, thereby forming an atomic layer at the bottom of the gap and around the bottom of the gap.

[0169] The supply of the first reactant R1 and the second reactant R2 as described above can be simultaneously performed on the processing area 310 of the substrate 300 through the second supply unit 421 and the third supply unit 422. During this process, in order to limit and / or prevent mixing of the first reactant R1 and the second reactant R2, the purge unit 450 provided around each of the second supply unit 421 and the third supply unit 422 can supply a purge gas between the processing areas 310.

[0170] As described above, by repeatedly supplying the first reactant R1 and the second reactant R2 to the processing area 310 of the rotating substrate 300, the interior of the gap formed in the processing area 310 can be filled at high speed. In addition, because the substrate 300 includes a plurality of processing areas 310 divided in space, and the gap filling operation can be performed on the plurality of processing areas 310 at the same time, the processing time can be reduced. Although one or more embodiments have been described, it will be understood by those skilled in the art that various changes in form and detail can be made therein without departing from the spirit and scope defined by the appended claims.

[0171] According to the above-described example embodiment, a precursor material that does not react with a co-reactant (such as H2O or O2) used in a sequential ALD process can be used as a reaction inhibitor, and a density gradient can be formed in which the density of the reaction inhibitor decreases from the entrance of the gap toward the bottom of the gap, thereby achieving bottom-up gap filling, thereby filling the gap with a filling material in a bottom-up direction.

[0172] Furthermore, a reaction suppressor can be formed using a precursor material having the same central metal as the precursor to be used in the sequential ALD process for forming the thin layer, thereby limiting and / or preventing the entrapment of impurities. The reaction suppressor can be converted into a filler material via an O3 or O2 plasma treatment, allowing for easy removal. Furthermore, after a filler layer is pre-formed to a certain thickness on the sidewalls and bottom of the gap, other filler layers can be sequentially formed in the gap. Consequently, the time required for gap filling can be reduced.

[0173] The method of filling a gap according to the above embodiment can be applied as a manufacturing technology for various devices requiring high precision and high aspect ratio, including optical devices, semiconductor devices, etc. Hereinafter, examples of various devices implemented by using the above method of filling a gap will be described.

[0174] Figures 24A to 24C is an electron microscope image showing a metalens 500 (in detail, a visible metalens) according to example embodiments. Figure 24B and Figure 24C 1 and 2 are an internal plan view and an internal cross-sectional view of the metalens 500 , respectively.

[0175] Reference Figures 24A to 24C , metalens 500 may include a nanostructure 515 including a plurality of gaps 510, and a filling layer 520 provided to fill the plurality of gaps 510. Here, filling layer 520 may include a high-refractive-index dielectric material having a higher refractive index than that of the material of nanostructure 515. For example, nanostructure 515 may include SiO2, and filling layer 520 may include TiO2.

[0176] Each gap 510 may have a nanometer-sized width. For example, each gap 510 may have an aspect ratio equal to or greater than about 10. By using the gap filling technology described above, the inner space of the gap 510 having a high aspect ratio may be filled with the filling layer 520 without defects such as voids.

[0177] The metalens 500 can be applied to various devices, such as near-eye display devices, smart phones, and drones. Figure 25 Augmented reality (AR) glasses 550 are shown as an example of a near-eye display device.

[0178] Figure 26 An example of a dynamic random access memory (DRAM) device 600 including an interconnect structure according to an example embodiment is shown.

[0179] Reference Figure 26 The interconnect structure of the DRAM device 600 may include an insulating layer 615 in which a plurality of gaps having a high aspect ratio are formed, and a filling layer 620 provided to fill the plurality of gaps. Here, the insulating layer 615 may include, for example, an interlayer dielectric (ILD), an intermetallic dielectric (IMD), etc. In addition, the filling layer 620 may include a highly conductive metal material.

[0180] By filling each gap having a high aspect ratio in the interconnect structure with a conductive material by using the above-described gap filling technique, a seamless interconnection without voids can be formed.

[0181] Figure 27 An example of a three-dimensional (3D) NAND flash memory device 700 according to example embodiments is shown.

[0182] Reference Figure 27 , multiple memory cells M1, M2, ..., and Mn can be stacked in a vertical direction. In addition, a gap 710 with a high aspect ratio can be formed to penetrate the multiple memory cells M1, M2, ..., and Mn, and a filling layer 720 including an insulating material can be filled in the gap 710. By filling the gap 710 with a high aspect ratio with an insulating material using the above-mentioned gap filling technology, a filling layer 720 without defects such as voids can be formed.

[0183] The above devices 500 , 600 , and 700 are merely examples. In addition to the devices 500 , 600 , and 700 , the gap-filling technology according to the embodiment can also be applied to manufacture various devices requiring a high aspect ratio and high precision.

[0184] The above-mentioned devices 500 , 600 and 700 may be applied to electronic devices.

[0185] Figure 28 is a block diagram of an electronic device according to an embodiment.

[0186] Reference Figure 28 , the electronic device 800 may include a processor 820, a memory 830, and a display device 840 electrically coupled together via a bus 810. The display device 840 may include a near-eye display device, such as the one described above. Figure 25 , but example embodiments are not limited thereto. In other embodiments, the display device 840 may include an LED display or other display, and may include one or more filler layers provided in corresponding gaps, wherein the filler layers are provided using one of the aforementioned embodiments. The memory 830, which may be a non-transitory computer-readable medium, may store instruction programs and / or other information. In some embodiments, the memory 830 may include a computer program that is readable by a computer. Figure 26 The DRAM device 600 described in and / or in Figure 27 , but example embodiments are not limited thereto. In some embodiments, the memory 830 may include other types of memory, such as phase change random access memory (PRAM), magnetoresistive RAM (MRAM), resistive RAM (ReRAM), ferroelectric RAM (FRAM), static RAM (SRAM), etc. The processor 820 may run a stored instruction program to perform one or more functions. For example, the processor 820 may be configured to process electrical signals generated by an image sensor (not shown). The processor 820 may be configured to generate an output (e.g., an image to be displayed on a display interface) based on such processing.

[0187] One or more of the elements disclosed above may include or be implemented in a processing circuit, such as hardware including logic circuitry; a hardware / software combination, such as a processor running software; or a combination thereof. For example, more specifically, the processing circuit may include, but is not limited to, a central processing unit (CPU), an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a system on a chip (SoC), a programmable logic unit, a microprocessor, an application-specific integrated circuit (ASIC), and the like.

[0188] It should be understood that the embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should generally be considered applicable to other similar features or aspects in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the appended claims.

[0189] This application claims the benefit of Korean Patent Application No. 10-2020-0075031, filed on June 19, 2020, and Korean Patent Application No. 10-2021-0055001, filed on April 28, 2021, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entirety.

Claims

1. A method for filling a gap formed on a substrate using atomic layer deposition (ALD), the method comprising: forming a first reaction-inhibiting layer by adsorbing a reaction inhibitor onto sidewalls of the gap, the reaction inhibitor comprising a precursor material that does not react with the second reactant, the first reaction-inhibiting layer having a density gradient in which a density of the reaction inhibitor decreases toward a bottom of the gap; forming a first precursor layer by adsorbing a first reactant onto the bottom of the gap and sidewalls of the gap around the bottom of the gap; as well as forming a first atomic layer on the bottom of the gap and the sidewalls of the gap around the bottom of the gap, wherein forming the first atomic layer includes adsorbing the second reactant onto the first precursor layer, The reaction inhibitor comprises a central metal and a cyclopentadienyl (Cp) ligand, a central metal and a pentamethylcyclopentadienyl (Cp*) ligand, Hf( t BuO)4、Hf(O i Pr)4 or Hf(O t Bu)(NEtMe)3.

2. The method according to claim 1, wherein The density gradient of the first reaction inhibition layer is determined according to the following equation: in, l represents the depth (nm) of the position on the side wall of the gap where the reaction inhibitor is adsorbed, w represents the width of the gap (nm), P represents the partial pressure of the reaction inhibitor in the reaction chamber (Pa), t represents the exposure time of the reaction inhibitor (s), S represents the saturation dose (≒2.5×10 18 molecules·m), m represents the molecular mass of the reaction inhibitor (kg), k represents the Boltzmann constant 1.38×10 -23 J / K, and T represents the temperature in the reaction chamber (K).

3. The method according to claim 1, wherein The reaction inhibitor is oxidized by O 3 or O 2 plasma.

4. The method according to claim 1, further comprising: The reaction inhibitor is converted into the material of the first atomic layer through O 3 or O 2 plasma treatment.

5. The method according to claim 1, wherein The reaction inhibitor does not react with H2O or O2.

6. The method according to claim 1, wherein The reaction inhibitor includes TiCp*(OMe)3, Ti(CpMe)(O i Pr)3, Ti(CpMe)(NMe2)3, ZrCp(NMe2)3, ZrCp2Cl2, Zr(Cp2CMe2)Me2, Zr(Cp2CMe2)Me(OMe), HfCp(NMe2)3 or Hf(CpMe)(NMe2)3.

7. The method according to claim 1, wherein The reaction inhibitor has the same central metal as the metal of the first reactant.

8. The method according to claim 1, wherein The first reactant includes TiCl4, Ti(O i Pr)4, Ti(NMe2)4, Ti(NMeEt)4, Ti(NEt2)4, ZrCl4, Zr(NMe2)4, Zr(O t Bu)4, ZrCp2Me2, Zr(MeCp)2(OMe)Me, HfCl4, Hf(NMe2)4, Hf(NEtMe)4, Hf(NEt2)4, HfCp2Me2 or Hf(MeCp)2(OMe)Me.

9. The method according to claim 1, wherein The second reactant includes H2O or O2.

10. The method according to claim 1, wherein The average density of the reaction inhibitor increases as the partial pressure of the reaction inhibitor in the reaction chamber increases.

11. The method according to claim 1, wherein Adsorption of the reaction suppressor is repeatedly performed for a plurality of cycles, and the average density of the reaction suppressor increases as the number of cycles increases.

12. The method according to claim 1, further comprising: forming a first filling layer by repeatedly performing forming the first precursor layer and forming the first atomic layer in a plurality of cycles, The first filling layer and the first reactant include the same metal.

13. The method according to claim 12, wherein: The density of the reaction inhibitor decreases toward the bottom of the gap, so that the first filling layer is formed in a bottom-up direction from the bottom of the gap. 14 . The method according to claim 13 , wherein the first filling layer is formed to have a shape that varies according to an average density of the reaction suppressor.

15. The method according to claim 14, wherein The first filling layer has a shape in which the first filling layer is formed in a bottom-up direction from the bottom of the gap.

16. The method according to claim 14, wherein The first filling layer has a shape in which the first filling layer is formed from the bottom of the gap and the sidewall of the gap around the bottom of the gap.

17. The method according to claim 14, wherein: The gap-filling process time is adjusted according to the shape of the first filling layer.

18. The method according to claim 12, further comprising: After forming the first filling layer, forming a second reaction inhibiting layer on the sidewall of the gap; forming a second precursor layer on an upper surface of the first filling layer and on the sidewalls of the gap around the upper surface of the first filling layer; as well as A second atomic layer is formed on the upper surface of the first filling layer and the sidewalls of the gap around the upper surface of the first filling layer.

19. The method according to claim 18, further comprising: By repeatedly performing the forming of the second precursor layer and the forming of the second atomic layer in a plurality of cycles, a second filling layer is formed in a bottom-up direction from the upper surface of the first filling layer.

20. A device comprising: A structure defining a gap having a high aspect ratio; as well as a filling layer in the gap, wherein The filling layer is formed in the gap using the method according to claim 1 .

21. The device of claim 20, wherein the gap has a nanometer-sized width and an aspect ratio equal to or greater than 10.

22. The device according to claim 20, comprising: A metalens comprising the structure defining the gap, wherein The structure defining the gap is a nanostructure in which the gap is formed, and The filling layer fills the gap and has a higher refractive index than that of the nanostructure.

23. The device according to claim 22, wherein The nanostructure includes SiO2, and The filling layer includes TiO2.

24. The device according to claim 20, wherein The structure defining the gap comprises an interconnect structure including an insulating layer in which the gap is formed, The filling layer fills the gap, and The filling layer includes a conductive material.

25. The device of claim 20, wherein The structure defining the gap includes a three-dimensional (3D) NAND flash memory device including a memory cell, the gap penetrating the memory cell, The filling layer fills the gap, and The filling layer includes insulating material.

26. A method of filling a gap formed on a structure using atomic layer deposition (ALD), the structure defining the gap and including a first reaction inhibition layer, the first reaction inhibition layer including a reaction inhibitor adsorbed onto a sidewall of the gap, the method comprising: forming a first precursor layer by adsorbing a first reactant onto a first exposed region of the gap, the first exposed region of the gap including a bottom of the gap and a first portion of the sidewall of the gap around the bottom of the gap, the first reaction-inhibiting layer defining the first exposed region of the gap based on the first reaction-inhibiting layer having a density gradient in which a density of the reaction inhibitor decreases toward the bottom of the gap, such that the first reaction-inhibiting layer exposes the first portion of the sidewall of the gap and the bottom of the gap, the reaction inhibitor comprising a precursor material; as well as forming a first atomic layer on the first exposed region of the gap by adsorbing a second reactant onto the first precursor layer, the second reactant being a material that does not react with the precursor material in the reaction inhibitor, The reaction inhibitor comprises a central metal and a cyclopentadienyl (Cp) ligand, a central metal and a pentamethylcyclopentadienyl (Cp*) ligand, Hf( t BuO)4、Hf(O i Pr)4, or Hf(O t Bu)(NEtMe)3.

27. The method according to claim 26, wherein The reaction inhibitor is oxidized by O 3 or O 2 plasma.

28. The method of claim 26, further comprising: The reaction inhibitor is removed by converting the reaction inhibitor into a material of the first atomic layer through O 3 or O 2 plasma treatment.

29. The method according to claim 26, wherein The second reactant includes H2O or O2.

30. A device comprising: The filling layer formed using the method according to claim 26, wherein The filling layer is provided in the gap, and The gap has a high aspect ratio.

31. The device according to claim 30, wherein The gap has a nanometer-sized width and an aspect ratio equal to or greater than 10.

32. The device according to claim 31, comprising: A metalens comprising the structure in which the gap is formed, wherein The refractive index of the filling layer is higher than the refractive index of the region of the structure surrounding the gap.

33. The device of claim 30, wherein wherein the structure forming the gap is an insulating layer, and The filling layer in the gap includes a conductive material.

34. The device of claim 30, wherein The structure in which the gap is formed includes a memory cell.

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