Dielectric material and method for forming the same

Abstract

A dielectric material and a method for forming the same are provided. The dielectric material includes a film comprising a layer of two-dimensional (2D) material, wherein the film has a dielectric constant (κ) of 3.0 or less. A method for forming the dielectric material is also provided.

Description

[Technical Field] 【0001】 Technical field The present invention relates to a dielectric material and a method for forming the same. [Background technology] 【0002】 background Traditionally, the dielectric constant has been reduced by increasing the porosity of dielectric materials. However, this trade-off is detrimental to the manufacturing and construction of devices, particularly their mechanical strength, yet it is still used because there are no alternative materials. 【0003】 Existing dielectric materials also cannot be thinned without sacrificing dielectric properties. [Overview of the Initiative] [Problems that the invention aims to solve] 【0004】 Therefore, improved dielectric materials and methods for forming them are needed. [Means for solving the problem] 【0005】 Summary of the Invention The present invention aims to address these problems and / or provide improved dielectric materials, particularly two-dimensional (2D) materials. 【0006】 According to a first aspect, the present invention provides a dielectric material comprising a film containing a layer of two-dimensional (2D) material, wherein the film has a dielectric constant (κ) of 3.0 or less. 【0007】 In certain embodiments, the 2D material may include a single layer of amorphous carbon (MAC). 【0008】 The film may have a thickness of 20 nm or less. For example, the film may have a thickness of 0.5 to 3 nm. 【0009】 In particular, the membrane may contain at least two layers of 2D MAC. For example, the membrane may contain 2 to 5 layers of 2D MAC. 【0010】 The film can have a hardness exceeding 10 GPa. The film is 8 MV cm -1 It may have extremely high dielectric strength. 【0011】 In certain embodiments, the membrane may be non-porous. 【0012】 In certain embodiments, the film can be formed on at least a portion of the non-catalytic substrate. In particular, the non-catalytic substrate may include silicon-based substrates, carbon-based substrates, metallic substrates, oxides, transition metal dichalcogenides, maxine, or any combination thereof. For example, the non-catalytic substrate may include cobalt, gold, copper, nickel, tungsten, molybdenum, ruthenium, niobium, silicon dioxide, silicon nitride, titanium nitride, tantalum nitride, cobalt oxide, tungsten carbide, germanium, gallium arsenide (GaAs), silver, stainless steel, fernico, manganese, aluminum, or any combination thereof. 【0013】 According to a second embodiment, a method for forming a dielectric material is provided, which includes depositing carbon radicals on a substrate. 【0014】 In certain embodiments, the method may further include repeatedly depositing carbon radicals to form up to five layers of a 2D MAC. 【0015】 In another specific embodiment, depositing carbon radicals may include forming carbon radicals via photodissociation of a carbon source. Depositing carbon radicals may also include forming carbon radicals via UV wavelength absorption of a carbon source. In particular, the UV wavelength may be 200-400 nm. The carbon source may include acetylene, methane, acetylene, ethylene, ethanol, propane, naturally attached carbon, or any combination thereof. 【0016】 According to certain aspects, the substrate may include a non-catalytic substrate. In particular, the non-catalytic substrate may include a silicon-based substrate, a carbon-based substrate, a metal-based substrate, an oxide, a transition metal dichalcogenide, a MAX phase, or any combination thereof. For example, the non-catalytic substrate may include cobalt, gold, copper, nickel, tungsten, molybdenum, ruthenium, niobium, silicon dioxide, silicon nitride, titanium nitride, tantalum nitride, cobalt oxide, tungsten carbide, germanium, gallium arsenide (GaAs), silver, stainless steel, permalloy, manganese, aluminum, or any combination thereof. 【0017】 The deposition may be in a plasma environment. According to certain aspects, the method may further include generating a plasma environment prior to deposition. For example, the plasma environment may include a remote inductively coupled plasma. 【0018】 Brief Description of the Drawings In order for the present invention to be understood in detail and to be readily put into practice, exemplary embodiments will now be described by way of non-limiting examples only, with reference to the accompanying exemplary drawings. 【Brief Description of the Drawings】 【0019】 [Figure 1]This shows the direct growth of a single-layer amorphous carbon. Figures 1(a)–(c) show cross-sectional transmission electron microscope (TEM) images of MAC on SiO2 / Si with thicknesses of 3L, 2L, and 1L (layer), respectively, and the superposition of EELS maps shows the distribution of C and O2 for accurate thickness determination. Figure 1(d) shows a 4-inch Si / SiO2 wafer, which is mostly covered with a 1.5 nm MAC layer (ML-AC) and is clearly distinguishable from the substrate by optical contrast (i.e., ML-AC represents the first segment, SiO2 represents the second segment, and the second segment is located on the side of the wafer). Figure 1(e) shows atomic force microscope (AFM) thickness measurements of 1-4L MAC films directly grown on SiO2 as a function of growth time, with each layer numbered: 1L is represented by 1a and 1b, 2L by 2a and 2b, 3L by 3a-3d, and 4L by 4a-4d (the letter closest to each layer number indicates completeness; maximum completeness for single and double layers is achieved with the letter "b", and for more layers it is achieved with "d"). Figures 1(f)-(j) show top-surface TEM images at atomic resolution, illustrating the sequential growth of each layer. Figures 1(f), 1(h), and 1(j) correspond to the complete 1L, 2L, and 3L layers of MAC, while Figures 1(g) and 1(i) correspond to the incomplete second and third layers, respectively. Growth progresses over time from 1L to 2L for the second layer and from 2L to 3L for the third layer. Figures 1(k) to 1(m) show scanning transmission electron microscope (STEM) images of the 1L, 2L, and 3L MAC after transfer from SiO2, respectively. [Figure 2a] The AFM analysis of MAC thickness as a function of time is shown, along with the synthesis time and the number of layers. [Figure 2b] The AFM analysis of MAC thickness as a function of time is shown, along with the synthesis time and the number of layers. [Figure 2c] The AFM analysis of MAC thickness as a function of time is shown, along with the synthesis time and the number of layers. [Figure 2d] The AFM analysis of MAC thickness as a function of time is shown, along with the synthesis time and the number of layers. [Figure 2e]The AFM analysis of MAC thickness as a function of time is shown, along with the synthesis time and the number of layers. [Figure 2f] The AFM analysis of MAC thickness as a function of time is shown, along with the synthesis time and the number of layers. [Figure 2g] The AFM analysis of MAC thickness as a function of time is shown, along with the synthesis time and the number of layers. [Figure 2h] The AFM analysis of MAC thickness as a function of time is shown, along with the synthesis time and the number of layers. [Figure 2i] The AFM analysis of MAC thickness as a function of time is shown, along with the synthesis time and the number of layers. [Figure 2j] The AFM analysis of MAC thickness as a function of time is shown, along with the synthesis time and the number of layers. [Figure 2k] The AFM analysis of MAC thickness as a function of time is shown, along with the synthesis time and the number of layers. [Figure 2l] The AFM analysis of MAC thickness as a function of time is shown, along with the synthesis time and the number of layers. [Figure 3] This section outlines the spectroscopic analysis of MAC samples. Figure 3(a) shows typical Raman spectra for different growth times (the letters and numbers to the right of each line indicate the layer and its completeness). Figure 3(b) shows an optical image of a set of metal wires covered with MAC, the metal wires are shown in the inset. Figure 3(c) shows individual Raman spectra collected from SiO2, Cu, and Co surfaces (the inset shows the scheme of Figure 3(b)). Figure 3(d) shows the C1s line as a function of growth time (the letters and numbers to the right of each line indicate the layer and its completeness), the sample matches Figure 1. Figure 3(e) shows the similarity of the C1s line of MAC grown on metal and insulating substrates. Figure 3(f) shows the NEXAFS spectra of monolayer (solid line) and 4-layer (dashed line) samples with the dependence of 1s-π* and 1s-σ* transitions on the angle of incidence (the experimental shape for the monolayer sample is shown in the inset). [Figure 4]This shows the uniform growth of MAC. Figure 4(a) shows the EELS carbon k-edge spectra of 1L, 2L, and 3L samples corresponding to Figures 1(a)-(c). Figures 4(b) and 4(c) show the Raman signals with uniform characteristics across the entire 4-inch wafer, where points on the wafer are marked p1, p2, and p3, and spectra were collected from these points. Figure 4(d) shows an AFM image of a near-atomic-level smooth surface of a MAC film grown on Si / SiO2. Figures 4(e)-(g) show the initial pure state of the growth substrate after MAC deposition for Co, Cu, and Si, respectively. [Figure 5] The hardness of MAC is shown. Figure 5(a) shows the hardness of a 2.1 nm thick MAC film on SiO2, measured by AFM indentation, compared to a reference sample of SiO2 alone. Figures 5(b) to (c) show the AFM morphology of uniform indentation of SiO2 and MAC on SiO2. [Figure 6] A schematic diagram of a metal interconnect stack with a low-κ dielectric surrounding a conductive element is shown. In the inset, the complex structure of multiple layers surrounding each line is revealed, and a simplified structure is exemplified on the right, as shown in the enlarged region. [Figure 7] This shows conformal coating by MAC. Figures 7(a) to (c) show cross-sectional TEM and corresponding EELS maps illustrating conformal coating of silicon dioxide trenches. [Figure 8a] Cross-sectional TEM and corresponding EELS maps showing conformal coating of cobalt lines by MAC layers are shown. A wide scan overview of several lines covered with ML-AC is also shown. [Figure 8b] This shows a cross-sectional TEM and corresponding EELS map illustrating the conformal coating of cobalt lines by the MAC layer. A magnified view of one of the lines is also shown. [Figure 8c] The image shows a cross-sectional TEM and corresponding EELS map illustrating conformal coating of cobalt wires by a MAC layer. An EELS overlay with the indicated layer is also shown. [Figure 9a]The AFM images and time-dependent thickness profiles of 80 nm thick cobalt lines on a Si / SiO2 substrate without a 1.5 nm MAC layer after 72 hours of exposure to ambient conditions are shown. [Figure 9b] The AFM images and time-dependent thickness profiles of 80 nm thick cobalt lines on a Si / SiO2 substrate with a 1.5 nm MAC layer are shown after 72 hours of exposure to ambient conditions. [Figure 10a] This shows a set of 100 nm wide copper wires protected by an ML-AC layer after exposure to a 7% APS solution for 30 seconds. [Figure 10b] This shows a set of 100 nm wide copper wires without protection by an ML-AC layer after exposure to a 7% APS solution for 30 seconds. [Figure 11] The dielectric and metal diffusion barrier performance of directly grown MACs are shown. Figure 11(a) shows low-frequency dielectric spectroscopy data where the dielectric constant κ of approximately 1.34 is independent of the MAC thickness. Figure 11(b) shows the capacitance as a function of frequency for various thicknesses, and the impedance hodogram measured for the MAC is shown in the inset, showing that the MAC capacitance does not change in the frequency range of 100 Hz to 100 kHz. Figure 11(c) shows the dependence of the breakdown voltage on dielectric thickness, exhibiting dielectric strength of 28 to 31 MVcm-1. Figure 11(d) shows copper ion diffusion experiments demonstrating at least a two-order-of-magnitude improvement in failure time from existing 10-year benchmark values ​​when the ln(TTF)~E and ln(TTF)~√E models are applied (the triangular symbol (SiO2) indicates a comparison of substrate behavior). Figure 11(e) shows a comparison of linear model fits of TTF for replacements in the latest reports of existing tunnel barriers (TaN is indicated by left-pointing triangles and hBN is indicated by right-pointing triangles). [Figure 12]The optical characterization of the dielectric constant is shown. Figure 12(a) shows optical ellipsometry data of the imaginary and real parts of the dielectric constant, supporting the results obtained in the low-frequency range. Figures 12(b)-(c) show dielectric spectroscopic fits of psi and delta spectra collected at different incident angles by the Cody-Lorentz-Urbach model (the angles increase from 40 to 70 degrees in 5-degree increments from the upper curve to the lower curve, and the other layers considered in the model are a silicon substrate and silicon dioxide reflector with a thickness of 87.4 nm, determined by cross-sectional TEM measurements). Figures 12(d)-(e) show UV-vis spectroscopic data of MACs of various thicknesses. Figure 12(e) shows the data in the form of a Tauc plot, and the corresponding direct band gap is extracted. [Figure 13] The breakdown and leakage measurements for MIM devices are shown. Figure 13(a) shows an optical image of an MIM capacitor (Au metal plate) with varying capacitor plate area of ​​50 × 50 μm²d and 500 × 500 nm²h. Figures 13(b) and (f) show the IV curves measured for the devices shown in Figures 13(a) and 13(d), where a circle (1L) represents a single layer, a cross (2L) represents two layers, a star (3L) represents three layers, and a square (4L) represents four layers, respectively. In (b), the horizontal and vertical dashed lines represent the low power limit current density of 1.5 × 10⁻² A cm⁻² and the transistor operating voltage of 0.7 V, and the allowable transistor operating range is in the lower right quadrant. Figures 13(c) and (g) show Weibull plots of the breakdown voltage extracted from 13(b) and 13(f), respectively. Figures 13(h) to (j) show the IV curves for scaling the capacitor plate size for layers 1, 2, and 3, respectively. [Figure 14] This shows breakdown and leakage current measurements using CP-AFM. Figure 14(a) shows a schematic of the CP-AFM experiment. Figure 14(b) shows the IV curves of 1, 2, and 3-layer MACs on an Au substrate (each spanning over 100 data points; the solid lines represent the average curve). Figure 14(c) shows a Weibull plot of the data shown in 14(b). [Modes for carrying out the invention] 【0020】 Detailed explanation As explained above, improved dielectric materials are needed. 【0021】 Generally, the present invention provides a dielectric material comprising a film containing a layer of two-dimensional (2D) material, wherein the film has a dielectric constant (κ) of 3.0 or less. For use in next-generation integrated circuits (ICs), ultra-low κ materials (κ < 2.5) with a thickness of less than 3 nm are desired. However, generally, it is difficult to reduce the thickness of a dielectric material without increasing κ. The dielectric material of the present invention is advantageous in that it has a low κ at a thin thickness, is non-porous, has excellent mechanical properties, and is corrosion-resistant. 【0022】 According to a first aspect, the present invention provides a dielectric material comprising a film containing a layer of two-dimensional (2D) material, wherein the film has a dielectric constant (κ) of 3.0 or less. 【0023】 For the purposes of this invention, the use of the singular form includes the plural form unless otherwise specified. Note that, as used herein and in the appended claims, the singular forms “a,” “an,” and “it” include multiple referents unless the context clearly indicates otherwise. Furthermore, the terms “encompassing,” “containing,” and “having,” as well as “encompassing,” “containing,” and “having,” are not considered limiting. 【0024】 For the purposes of this invention, reference to 2D materials refers to materials having a thickness of a single atomic layer. 2D materials may have an in-plane amorphous structure. 【0025】 The film may have a κ of 3.0 or less. For example, the film may have a κ of 2.5 or less. In particular, the film may have κ of 2.0 or less, 1.9 or less, 1.8 or less, 1.7 or less, 1.6 or less, 1.5 or less, 1.4 or less, and 1.3 or less. More specifically, the film may have a κ of 1.3 or less. The film may comprise one or more layers of a 2D material. According to a particular embodiment, the dielectric material may comprise the film and any suitable non-2D material having a κ of 3.0 or less. According to another particular embodiment, the dielectric material may comprise the film and any suitable non-2D material having a κ greater than 3.0. The non-2D material may comprise a non-catalytic wafer or any suitable substrate. 【0026】 The 2D material can be any suitable amorphous 2D material. The 2D material may have a κ of 3.0 or less. According to certain embodiments, the 2D material may include monolayer amorphous carbon (MAC). For the purposes of the present invention, MAC is defined as an analogue of monolayer crystalline carbon (graphene) having mainly sp2-like carbon and random orientation of in-plane bonds, where π bonds are broken, the relative contribution of σ bonds to material properties increases, and low-polarity carbon bonds in a disordered structure minimize the total polarizability. Since MAC contains only carbon, it is advantageous that there are no diffusion problems and it is compatible with many different substrates. MAC can have any suitable interlayer spacing. For example, MAC can have an interlayer spacing of 0.6 to 0.9 nm. In particular, the spacing of the intermediate layers can be 0.65 to 0.85 nm, 0.65 to 0.8 nm, or 0.7 to 0.75 nm. The interlayer spacing can be about twice that of graphene. In each monolayer of 2D MAC, MAC can have a similar number of carbon atoms as each monolayer of its similar monolayer crystalline carbon (graphene). Therefore, MAC can have about half the density of graphene. In particular, MAC can have 0.6-1.5 g / cm³ -3 It can have a density of . Therefore, using any other suitable amorphous 2D material such as MAC or monolayer amorphous boron nitride makes it possible to beneficially reduce the material density and at the same time obtain a low κ. 【0027】 The film contained in the dielectric material may have any suitable thickness. For example, the film may have a thickness of 20 nm or less. In particular, the film may have a thickness of 10 nm or less, 9 nm or less, 8 nm or less, 7 nm or less, 6 nm or less, 5 nm or less, 4 nm or less, 3 nm or less, 2 nm or less, or 1 nm or less. More specifically, the film may have a thickness of 3 nm or less. The film may have thicknesses of 0.5 to 3 nm, 0.65 to 2.6 nm, 0.8 to 2.4 nm, 1.3 to 2.1 nm, or 1.5 to 2 nm. The film may contain any suitable number of layers of 2D MAC. For example, the film may contain one or more layers of 2D MAC. In particular, the film may contain one, two, three, four, or five layers of 2D MAC. To obtain optimal performance, there are various specific thickness requirements based on scaling technology nodes and dimensions, and the dielectric material of this embodiment advantageously allows for the growth of different thicknesses by adjusting the number of MAC layers with a single-atom thickness. 【0028】 Each of the one or more layers of the 2D MAC may have a κ of 3.0 or less. Therefore, the film may have a κ of 3.0 or less, as described above. 【0029】 The film contained in the dielectric material can have an appropriate hardness. For example, the film can have a hardness of more than 10 GPa. In particular, the film can have a hardness of more than 20 GPa, more than 30 GPa, more than 40 GPa, more than 50 GPa, more than 60 GPa, more than 70 GPa, more than 80 GPa, more than 90 GPa, and more than 100 GPa. More specifically, the film can have a hardness of approximately 100 GPa. This mechanical stability enables the manufacture of standard devices for integrated circuits without the dielectric material collapsing. 【0030】 As explained above, in integrated circuits, reducing the thickness of the dielectric layer typically increases leakage current and degrades performance. The dielectric material of this embodiment advantageously enables device scaling with higher dielectric strength and prevents the increase in leakage current. In particular, the film can have high dielectric strength to meet requirements down to a single atomic layer thickness. For example, the film may be 8 MV cm thick. -1 It can have an dielectric strength of over 10 MV. -1Greater than 15 MV / cm -1 Greater than 20 MV / cm -1 Greater than 25 MV / cm -1 Greater than 30 MV / cm -1 It may have a dielectric strength greater than 30 MV / cm. More specifically, the film may have a dielectric strength greater than 30 MV / cm. -1 It may have a dielectric strength greater than. 【0031】 The film included in the dielectric material may be non-porous. For the purposes of the present invention, reference to non-porous refers to the absence of pores on and within the film. The absence of pores may mean the absence of pores or holes having dimensions of about 1 nm or greater, but is not limited thereto. The non-porous film advantageously makes it possible to improve resistance to degradation caused by moisture absorption or ion diffusion into the film. Further, additional layers of barrier (against diffusion of metal ions) and liner material (for adhesion of the dielectric material to the device structure) that further limit scaling of the size of the integrated circuit are not required since the film is resistant to such degradation. A simplified device architecture of the metal in direct contact with the dielectric material can be realized, thereby either increasing the volume of the metal lines for improving the conductivity of the wiring or enabling better interconnect performance with more aggressive size scaling. 【0032】 In certain embodiments, a film can be formed on at least a portion of a non-catalytic substrate. For the purposes of the present invention, reference to a non-catalytic substrate refers to any suitable substrate that does not participate in growth chemistry. In particular, a substrate may be considered non-catalytic and not participate in growth chemistry under the temperature conditions used when forming the film, even if it may become catalytically active at temperatures higher than the temperature for film formation. A non-catalytic substrate does not need to have a κ of 3.0 or less. Examples of suitable non-catalytic substrates include, but are not limited to, silicon-based substrates, carbon-based substrates, metallic substrates, oxides, transition metal dichalcogenides, maxine, or any combination thereof. In particular, non-catalytic substrates may include cobalt, gold, copper, nickel, tungsten, molybdenum, ruthenium, niobium, silicon dioxide, silicon nitride, titanium nitride, tantalum nitride, cobalt oxide, tungsten carbide, germanium, gallium arsenide (GaAs), silver, stainless steel, fernico, manganese, aluminum, or any combination thereof. More specifically, the non-catalytic substrate may include silicon dioxide, silicon nitride, titanium nitride, copper, cobalt, and tungsten. 【0033】 A second aspect of the present invention provides a method for forming a dielectric material of the first aspect, the method comprising depositing carbon radicals on a substrate. For the purposes of the present invention, reference to carbon radicals refers to carbon species having one unpaired electron and readily reacting with other atoms or molecules. The deposition may be carried out by any suitable means. For example, the deposition may be carried out by chemical vapor deposition (CVD). In particular, the deposition may be carried out by laser-excited plasma chemical vapor deposition (LPE-CVD), laser CVD (LCVD), UV lamp-assisted CVD, or UV lamp-plasma-assisted CVD. 【0034】 The deposition of carbon radicals allows for the formation of one or more layers of 2D material on a substrate in any suitable time, thereby forming a dielectric material. For example, the deposition of carbon radicals may take longer than 1 minute. In particular, the deposition of carbon radicals may take longer than 1.5 minutes, 2 minutes, 2.5 minutes, 3 minutes, 3.5 minutes, 4 minutes, 4.5 minutes, 5 minutes, 5.5 minutes, 6 minutes, 6.5 minutes, 7 minutes, 7.5 minutes, 8 minutes, 8.5 minutes, 9 minutes, 9.5 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, 16 minutes, 17 minutes, 18 minutes, 19 minutes, and 20 minutes. According to a particular embodiment, the method may involve repeating the deposition to form up to five layers of 2D MAC. 【0035】 The deposition of carbon radicals may occur over any appropriate time with any appropriate stepwise growth increments until the desired number of layers is achieved. For example, the deposition of carbon radicals may be t i From minutes (initial time) to t f The time can increase in increments of 1 minute, 2 minutes, or any combination thereof until the final time. In particular, the gradual growth increments can be varied in alternating intervals such as 1 minute, 2 minutes, 1 minute, 2 minutes, and t f This can be repeated until it reaches [the desired result]. This means that there are fewer steps, but at the same time, an increase in the uniformity of each layer is achieved. 【0036】 The deposition of carbon radicals may include the formation of carbon radicals via photodissociation of a carbon source. The photodissociation of the carbon source may occur via any suitable light source having any suitable wavelength. For example, the light source may be an excimer laser, halogen lamp, diode lamp, diode laser, or gas laser. For example, the wavelength of the light source may be 0.01–2500 nm. In particular, the wavelengths of the light source may be 0.01–0.1 nm, 0.1–1 nm, 0.1–2000 nm, 1–1500 nm, 10–1000 nm, 100–500 nm, 150–450 nm, 200–400 nm, or 250–350 nm. Specifically, the deposition of carbon radicals may include the formation of carbon radicals via UV wavelength absorption of the carbon source. The UV wavelength may be any suitable UV wavelength for forming carbon radicals when the carbon source is exposed to UV wavelengths. For example, the UV wavelength may be 200–400 nm. The UV wavelength can be generated by any suitable apparatus. For example, UV wavelengths can be generated by an excimer laser or UV lamp. The excimer laser light source may include XeCl or KrF. The carbon source can be any suitable carbon source capable of forming carbon radicals under favorable conditions. For example, the carbon source may include acetylene, methane, acetylene, ethylene, ethanol, propane, naturally attached carbon, or any combination thereof. In particular, the carbon source may include acetylene. By using acetylene as the carbon source, the concentration of C2 radicals is favorably increased, disrupting the self-limiting decomposition behavior and enabling the growth of multiple layers of MAC without the need for a catalyst. 【0037】 The deposition of carbon radicals may occur at any appropriate pressure selected based on the carbon source. For example, the deposition of carbon radicals may occur at 10 -3 ~10 -2 It could be under pressure. 【0038】 In certain embodiments, the substrate may include a non-catalytic substrate. The non-catalytic substrate may be as described above. The substrate may be considered non-catalytic and may be catalytically active at higher temperatures, but not involved in growth chemistry at temperatures of about 20 to 500°C. In particular, the substrate may be considered non-catalytic at temperatures of about 50 to 450°C, 100 to 400°C, 150 to 350°C, and 200 to 300°C. Furthermore, the substrate may be considered non-catalytic at temperatures of about 250 to 350°C. 【0039】 As described above, the substrate may be directly exposed to UV wavelengths. In another embodiment, direct exposure of the substrate to UV wavelengths can be avoided to prevent possible surface damage. 【0040】 The deposition of carbon radicals can occur in a plasma environment. The plasma environment advantageously supplies additional energy to the carbon radicals. Therefore, the higher-frequency carbon radicals are in the optimal energy range for photodissociation by a UV source of a specific wavelength, increasing the concentration of activated carbon radicals and thereby promoting deposition on the substrate. According to certain embodiments, the method may further include generating a plasma environment before deposition. For example, generating a plasma environment may include a remotely inductively coupled plasma. 【0041】 Therefore, this method is an improved method that enables direct and conformal growth of films. This is particularly important for applications in integrated circuits, where the film must cover all areas around trenches and vias, and thus grow continuously, and must be able to connect to all sides of any high-aspect-ratio device structure, such as pre-patterned pillars and trenches, but not limited to these. This method is typically used to promote conformal growth, but it also allows for the elimination of liner materials, which are not ideal in many deposition methods. Furthermore, film growth occurs throughout the entire volume, thus eliminating the need to directly apply an excimer laser to the surface, which is a significant feature for any further industrial applications. 【0042】 While the present invention has been described in general terms here, it is not intended to be limited, but rather to be more readily understood by referring to the following exemplary embodiments. [Examples] 【0043】 Examples Materials and methods 10 -8 ~10 -7 Non-catalytic direct growth was performed using a chemical vapor deposition (CVD) setup chamber operating at a base pressure level of mbar. A UV excimer XeCl laser (λ=308nm) was used to initiate photodecomposition of the carbon source (acetylene, C2H2), and an Ar plasma was introduced into the setup using a remote inductively coupled plasma (PIE Scientific) source. The sample was mounted in a stainless steel holder (two operating modes: direct and indirect exposure of the sample to the laser). For Cu foil, Si, and Si / SiO2 substrates, the sample surface was directly exposed to the excimer laser. Direct exposure of the surface to laser radiation was avoided to prevent potential surface damage when fabricating devices on the same substrate or in indirect exposure modes. The same conditions could be used to dissociate the carbon source even when the laser was near the sample but not in contact with it, but step heating up to 300°C was used to aid growth. 【0044】 The growth of single-layer amorphous carbon was achieved by excimer laser photodecomposition of the carbon source. By increasing the concentration of C2 radicals using acetylene and adding a remotely inductively coupled plasma, both the concentration and activity of the carbon radicals were increased, promoting deposition on a substrate, such as silicon oxide. 【0045】 Similar results were obtained for MAC synthesis even when the excimer laser (XeCl or KrF source) was replaced with a UV lamp source. 【0046】 Characteristic evaluation The thicknesses of different MACs were investigated using cross-sectional transmission electron microscopy (TEM) images (Figures 1(a)-(c)) taken from arbitrary positions (Figure 1(d)) on a uniformly coated 2-inch wafer, along with elemental mapping by electron energy loss spectroscopy (EELS, insets in Figures 1(a)-(c)), atomic force microscopy (AFM) (Figures 1(e) and 2), and ellipsometry measurements. More than 10 samples were measured by cross-sectional TEM, and more than 20 samples by AFM and ellipsometry, with thicknesses corresponding to layered MACs. Three representative samples with thicknesses corresponding to 3, 2, and 1 layer of MAC (3L, 2L, and 1L, respectively) are shown in Figures 1(a)-(c). The EELS maps shown in the insets of each panel improve the accuracy of the thickness measurements, with red corresponding to the sp2 shoulder of the carbon peak and blue corresponding to oxygen. Individual thickness variations were observed from a 3L sample of 2.1 nm (Figure 1(a)) to a 2L sample of 1.45 nm (Figure 1(b)) and a single layer of 0.8 nm (Figure 1(c)). The measured thickness interval of 0.65 nm is consistent with the interlayer distance, and the single layer thickness is consistent with previous literature. Figure 1(e) shows the measured AFM thickness of 1–4L MAC films grown directly on SiO2. The order of the data points and their labels corresponds to the thickness measured by AFM. From bottom to top, the growth time increases from 1 minute to 12 minutes in 1-minute increments. 【0047】 To illustrate the amorphous structure, atomic-resolution TEM was performed on suspension samples transferred to a Si3N4 TEM grid. Layer-by-layer growth of ML-AC was demonstrated in top-view images of ML-AC grown at different synthesis times (Figures 1(f)-(j)). Figures 1(f), 1(h), and 1(j) correspond to the completed 1L, 2L, and 3L MAC layers, while Figures 1(g) and 1(i) show the intermediate growth times of the second layer (1-2L) and third layer (2-3L), respectively. Three representative examples are shown: a single layer transferred from an SiO2 substrate (Figure 1(k)), a two-layer transferred from SiO2 (Figure 1(l)), and a three-layer transferred from SiO2 (Figure 1(m)). Furthermore, atomic-resolution TEM images revealed linked but distorted carbon rings composed of varying numbers of atoms. Local moiré fringes can be observed in overlapping nanocrystalline regions within each layer of the multilayer samples. Despite the lack of periodicity in the structure, it advantageously did not have any holes or defects. 【0048】 Detailed thickness-versus-time analysis was performed on samples with a patterned set of trenches etched into the MAC by AFM (see Figure 2). During the first two minutes of growth, the thickness remained constant in the sub-nm range (Figures 2(a) and 2(b)). Over the following two minutes, the thickness increased by 0.65 nm, but remained similar for these two samples. This is likely because the AFM failed to separate the islands in the sample grown for three minutes, while the sample grown for four minutes had a complete second layer. Furthermore, samples corresponding to growth times of 5, 6, 7, and 8 minutes (Figures 2(e), 2(f), 2(g), and 2(h)) all had a thickness of approximately 2.1 nm, and the top layer became more complete as the growth time increased. Finally, in the last set of samples with growth times of 9, 10, 11, and 12 minutes (Figures 2(i), 2(j), 2(k), and 2(l)), the measured average thickness was 2.7 nm, which corresponded to four layers. The data were plotted in Figure 1(e). 【0049】 MACs grown directly on SiO2 were characterized at a maximum centimeter scale to evaluate their uniformity. A 4'' diameter Si / SiO2 (90 nm thick SiO2) wafer was covered with two layers of MAC. An optical photograph of the wafer is shown in Figure 1(d), which visually demonstrates uniform thickness and a clear contrast between the MAC-covered area and the substrate. Raman mapping (10,000 points) was used to confirm the amorphous properties and uniformity down to the micron level. Figure 3(a) shows the average spectra across the wafer surface for various growth periods. It is also noteworthy that the spectra from the Cu and Co surfaces were similar to those observed on SiO2, and therefore the surface did not affect the growth mechanism (as seen in Figures 3(b) and 3(c)). As seen in Figure 3(b), the Raman spectroscopy mapping of the G peak intensity shows the large-scale continuity of the formed MAC film. G A uniform distribution can be observed. Individual spectra are shown in Figure 3(c), further demonstrating the remarkable technical effect that this embodiment enables surface-independent deposition on Cu and / or Co surfaces with only limited variability. 【0050】 X-ray photoelectron spectroscopy (XPS) was applied to investigate the elemental composition, chemical state, and electronic state of atoms in the MAC film and the growth substrate. Using XPS, large-scale sp2 hybridization of the samples was confirmed, which was consistent with the local findings obtained by EELS. C1s core-level spectra captured for various growth times are shown in Figure 3(d) (times increase from 1 minute to 12 minutes in 1-minute increments from bottom to top). C1s core-level spectra captured from MACs grown on different substrates are shown in Figure 3(e). These confirmed sp2 hybridization of carbon, and the sp3 contribution was negligible or nearly zero. These data, combined with the core-level spectra of the substrate material (Figures 4(e)-(g)), also showed that no bonding to the substrate was formed. From Figures 4(e)-(g), it can be seen that no bonding or formation of carbides or any other compounds occurred on the substrate formed beneath the MAC. 【0051】 We studied the σ and π coupling systems using near-edge X-ray absorption fine structure (NEXAFS) to demonstrate the layered nature of MAC, and the results are shown in Figure 3(f). The observed behavior was distinctly different from that of graphene and more similar to amorphous systems in which the 1s-π* transition does not depend on the incident angle of the linearly polarized X-ray beam. As shown in Figure 3(f), the 1L and 4L layers of MAC yielded a consistent total electron yield while increasing the photon energy at various degrees in 30-degree increments. 【0052】 From the EELS spectra (Figure 4(a)), a strong sp2 shoulder (shown by a vertical dashed line) was observed at 284.4 eV for all samples, with a similar intensity ratio to the main carbon peak. This indicates that all thicknesses reported for 1L, 2L, and 3L remained the same, i.e., the predominantly sp2-like carbon structure. The intensity relative to energy loss for each sample (1L, 2L, and 3L) shows a uniform correspondence despite the differences in growth times at 1b, 2b, and 3d, respectively. 【0053】 Figure 4(b) shows representative points indicated by dots of different shapes labeled p1, p2, and p3, and Figure 4(c) shows the corresponding marked Raman spectra. The three locations identified across the wafer are close to the expected value of 0.85. D / I G They have the same spectrum at a ratio. This further demonstrates the remarkable effect of the signal being uniform and consistent across the entire 4-inch wafer. Therefore, the growth is not limited to wafer size, as it can be applied to even larger wafers such as 1-inch or 8-inch wafers. 【0054】 Using an AFM, thickness uniformity was measured at a microscale, as shown in Figure 4(d). The AFM image was featureless, and the roughness value of approximately 200 pm was consistent with the roughness value of SiO2. Unlike conventional amorphous thin films, no adsorption layers, islands, or clusters were observed, and the roughness distribution was uniform across the entire wafer. The histograms of the height distribution (surface roughness) of SiO2 and MAC on the SiO2 surface were indistinguishable, indicating conformal growth of MAC on SiO2. 【0055】 The hardness of the deposited MAC was also investigated using the nanoindentation AFM mode. This is an important mechanical criterion for its application as a dielectric in metal interconnects. As shown in Figure 5, the hardness was at least an order of magnitude higher than that of silicon dioxide. The unique combination of high hardness and low κ of MAC, unlike other existing materials, makes it a suitable candidate for back-end obline integration. 【0056】 application As schematically shown in Figure 6, we evaluated potential applications of metal interconnects. In addition to the surrounding low-κ dielectric, the interconnects typically have diffusion barriers and liner material layers, as shown in the enlarged inset. Such examples encompass the main requirement that the semiconductor industry demands of low-κ dielectric materials, namely conformal deposition of non-planar surfaces across several materials simultaneously. 【0057】 To demonstrate the ability of conformal coating on non-planar surfaces, 100 nm wide trenches of silicon dioxide were fabricated using electron beam lithography and fluorine-based plasma etching. Furthermore, as shown in Figures 7(a) and 7(b), these trenches were covered with MAC and analyzed by cross-sectional TEM combined with EELS. Representative data for two-layer MAC (1.5 nm) is shown. Figure 7(a) shows a wide scan across multiple trenches simultaneously. Each trench yielded a uniform conformal coating with consistent growth of each different material interacting with each other. Figure 7(b) is a magnified view of one of the trenches, where SiO2, gold (Au), and platinum (Pt) can be seen. The magnified EELS map in Figure 7(c) allows for thickness measurement by material contrast, with the area labeled SiO2 showing a signal from oxygen (corresponding to the SiO2 layer), and the line marked with an arrow indicating the shoulder of sp2 carbon EELS. The observed thickness was uniform across the top, bottom, and sidewall surfaces of the trenches. The 2L ML-AC had a thickness of 1.45 nm and was uniformly distributed along the intersection of SiO2 and Au. Uniformity of material deposition is crucial for reliable electronic performance, and it is desirable to avoid regions with varying thicknesses that lead to different electrical properties. Therefore, this embodiment demonstrates uniform deposition of a material with a thickness of 1.45 nm, thereby advantageously improving the uniformity of electrical performance, which leads to improved reliability of electronic performance. 【0058】 It was further demonstrated that growth can occur simultaneously across different materials. MAC was grown on the surface of a cobalt wire, 100 nm wide, 60 nm high, and 0.5 micron pitch, defined by lithography on a Si / SiO2 substrate as shown in Figure 8(a). The angle between the sidewall of the cobalt wire and the silicon dioxide substrate was approximately 90 degrees, which corresponds to 0.6 nm. -1This corresponds to the extreme curvature level. Complete deposition in such highly curved regions is difficult for 2D materials due to the limited possible curvature of the lattice, but this was overcome using the present method and / or material. Data from cross-sectional TEM (Figure 8(b)) and EELS (Figure 8(c)) demonstrated conformal coating of cobalt wires with a MAC layer uniformly migrated to the SiO2 surface passing through the corners. The 2L ML-AC had a thickness of 1.45 nm and was uniformly distributed along the intersections between SiO2, Co, and Au. 【0059】 The formed film is advantageously free from any cracks or other defects. To demonstrate this, a test was conducted utilizing the high sensitivity of cobalt to oxygen and water, particularly at the sidewalls. Two sets of cobalt electrodes, one with a MAC layer and one without, were left in the air for 72 hours. As shown in Figures 9(a) and 9(b), the morphology of the untreated and protected lines was analyzed by AFM. From the profile in Figure 9(a), it is clear that there was a significant expansion of approximately 1.5 times due to oxidation. In contrast, the thickness of the protected line remained unchanged. Therefore, it can be seen that without MAC protection, the cobalt line expanded due to oxidation. The height (h) was approximately 150 nm. When the cobalt line was protected with MAC, the sample did not degrade over time, even in the presence of chemical reactions acting on the MAC-protected cobalt line, as seen at the bottom of Figure 9(b). The height (h) was approximately 75 nm. These data clearly show that the MAC deposits formed a continuous, impermeable film against water and oxygen molecules. Similar results were obtained for the Cu line by testing its chemical stability against common copper etchants (Figures 10(a) and (b)). 【0060】 The potential of MAC as an ultra-low κ dielectric and diffusion barrier was further evaluated. To demonstrate its low κ value, two independent experiments were performed: impedance spectroscopy in the low-frequency region and ellipsometry in the optical region. Dielectric constants were measured in electronic devices—a set of capacitors with varying dielectric layer thicknesses. The dependence of sample impedance on frequencies in the range of 100 Hz to 100 kHz was captured, and dielectric constants were further extracted to fit the data to LR / C circuits (see Figures 11(a) and (b)). For each thickness, at least 30 different samples had a constant κ value of 1.3 in the frequency range of 1 to 100 kHz. Thus, it can be seen that the dielectric constant remained constant across the entire thickness of the MAC layer from 1 L to 4 L. 【0061】 Overall, these two independent techniques confirmed that MAC possesses an ultra-low κ value in thicknesses ranging from 0.6 to 3 nm. This ultra-low κ value was achieved through the amorphous structure and single-element carbon properties of MAC. The independence of apparent thickness is uniquely observed for this material. 【0062】 This can be supported by referring to the NEXAFS data shown in Figure 3(f). Compared to graphene, the broadening of the lines corresponding to the 1s-π transition and the overall weak dependence on the angle of incidence typically reflect the degree of fault in the system, the presence of waveforms, and layer buckling. The smear and even weaker sensitivity of the 1s-σ transition to the angle of incidence also indicate the random orientation of the in-plane bond structure. π bonds are usually accompanied by delocalized electrons that move freely within the structure, and in crystalline graphene, they form a "π cloud" above and below the plane of the carbon atoms, contributing significantly to electron conduction. In MAC, this π network is disordered, and therefore the relative contribution of σ bonds to the dielectric constant increases. The dipoles associated with both bonds appear to be negligibly small, and these data indirectly explain the observed ultra-low dielectric constant. 【0063】 In addition to parasitic capacitive crosstalk, the dielectric used in metal interconnect stacks must block any breakdown leakage current between the conductive wires and active semiconductor components. To demonstrate this, the tunneling IV curve was measured using conductive AFM of MAC on metal pads and the dielectric strength was analyzed. Stress voltage sweeps were also performed in the capacitors used to extract the dielectric constant. The dielectric strength was 28–31 MVcm² at its maximum. -1 This was identified as the highest reported capacitance among 2D and 3D materials. The data is shown in Figure 11(c) (Capacitor = 28 MVcm²). -1 And C-AFM = Conductive Atomic Force Microscopy = 31 MV cm -1 ). 【0064】 The metal (Cu) interdiffusion barrier performance of the MAC layer was measured using a standard method of statistically analyzing current versus time at various applied bias voltages (Figure 11(d)). The failure time (TTF) determined by the linear ln(TTF)~E model in the operating field (approximately 0.5 MV / cm) was 10 12 It gave a failure time of 1 second, which was at least two orders of magnitude better than all commonly used materials reported recently (Figure 11(e)). The negligible change observed in MAC between 1L and 2L indicated that the metal diffusion fracture mechanism is not limited by MAC. The results proved that MAC has additional properties. This makes MAC ideal for novel advanced architectures of interconnect stacks, where the low-k dielectric also acts as a metal ion diffusion barrier. 【0065】 The low-frequency κ values ​​were supported by independent ellipsometry data shown in Figure 12(a). Ψ-Δ spectra collected at seven different incidence angles were processed using the Cody-Lorentz-Urbach model (Figures 12(b)–(c)). The increase in dielectric constant at short UV wavelengths coincided with the observed increase in absorption in this range (see Figures 12(d)–(e)). Towards lower frequencies, the real part of the dielectric constant gradually decreased to approximately 1.3. It is also natural that MAC has a slightly larger optical dielectric constant than that in the low-frequency region. 【0066】 The results of the breakdown IV curve are summarized in Figure 13. The same device previously used to measure the breakdown voltage (see Figures 13(a), (d), and (e)) was used. The breakdown voltage was measured using a large (50 × 50 μm) curve. 2 , Figures 13(b)~(c)) and small size (500×500nm) 2 (Figures 13(f)-(g)) showed consistency across devices and demonstrated high consistency with different thicknesses and varying capacitor plate sizes (Figures 13(h)-(i)-(j) for 1, 2, and 3L, respectively). As a result, it was shown that leakage current and breakdown voltage did not depend significantly on the plate area. These results were also supported by conductive probe AFM IV curves collected from gold metal plates covered with MAC of different thicknesses (Figure 14(b)). 【0067】 Applications in semiconductor integrated circuits MAC is an ideal ultra-low k dielectric material, satisfying the dielectric requirement of k<2 (MAC has k=1.3) and having a complete barrier layer at 0.6 nm (current existing ultra-low k dielectric materials are porous and require a barrier to prevent metal diffusion). 【0068】 Therefore, the metal wire core width can be maximized with the modified device structure. 【0069】 With MAC barriers, the liner + barrier is no longer part of the interconnect line width, as MAC is an ideal dielectric material for "space width." By combining MAC dielectrics with existing ULK dielectrics, increased metal wire core widths can be achieved. 【0070】 MAC can also be grown thicker to completely replace the ULK dielectric filling the "space width." This can reduce the space width because it is superior to the space width material of the existing dielectric. This increases the volume of the metal wire as much as possible for improved conductivity. Alternatively, the volume of the metal can remain the same at an optimal size while the focus is on reducing the space width in the overall interconnect scaling. By significantly increasing the volume of the interconnect metal, the bottleneck in interconnect scaling can be solved. 【0071】 Applications in Gate All-Around (GAA) transistors and FinFET spacers The spacing between the gate and source / drain contacts is a major limiting factor for such transistors due to high parasitic capacitance. The IRDS roadmap suggests that while first-generation GAA transistors are feasible with a 6nm spacer width and κ=3.3, there is no solution to reduce this by 4nm at κ=2.7. MAC enables reliable GAA transistor architectures at 2.1nm and κ=1.3. Furthermore, the spacer width can be further reduced to 0.6nm (and a thickness of approximately 4-6nm across the entire spacer width range) if needed. Table 1 shows possible dimensions for replacing spacer materials with MAC. 【0072】 [Table 1] 【0073】 Other advantages of MAC include ease of etching and selective etching for high lithographic resolution. Since MAC is composed of carbon, these characteristics make it highly advantageous for the semiconductor industry. Due to the amorphous carbon etching chemistry, it can also function as an etching protective layer for manufacturing with very low line and sidewall roughness. The MAC structure does not degrade after the manufacturing process, providing good performance. 【0074】 While the above description has presented exemplary embodiments, it will be understood by those skilled in the art that many variations can be made without departing from the present invention.

Claims

[Claim 1] A dielectric material comprising a film containing a layer of two-dimensional (2D) material, wherein the film has a dielectric constant (κ) of 3.0 or less. [Claim 2] The dielectric material according to claim 1, wherein the 2D material includes a single layer amorphous carbon (MAC). [Claim 3] The dielectric material according to claim 1 or 2, wherein the film has a thickness of 20 nm or less. [Claim 4] The film is a dielectric material according to any one of claims 1 to 3, having a thickness of 0.5 to 3 nm. [Claim 5] The dielectric material according to any one of claims 2 to 4, wherein the film comprises at least two layers of 2D MAC. [Claim 6] The dielectric material according to any one of claims 2 to 5, wherein the film comprises two to five layers of 2D MAC. [Claim 7] The film is a dielectric material according to any one of claims 1 to 6, having a hardness of more than 10 GPa. [Claim 8] The aforementioned film is 8 MV cm -1 A dielectric material according to any one of claims 1 to 7, having ultra-high dielectric strength. [Claim 9] The dielectric material according to any one of claims 1 to 8, wherein the film is non-porous. [Claim 10] The dielectric material according to any one of claims 1 to 9, wherein the film is formed on at least a portion of the non-catalytic substrate. [Claim 11] The dielectric material according to claim 10, wherein the non-catalytic substrate includes a silicon-based substrate, a carbon-based substrate, a metal-based substrate, an oxide, a transition metal dichalcogenide, maxine, or any combination thereof. [Claim 12] The dielectric material according to claim 10, wherein the non-catalytic substrate includes cobalt, gold, copper, nickel, tungsten, molybdenum, ruthenium, niobium, silicon dioxide, silicon nitride, titanium nitride, tantalum nitride, cobalt oxide, tungsten carbide, germanium, gallium arsenide (GaAs), silver, stainless steel, fernico, manganese, aluminum, or any combination thereof. [Claim 13] A method for forming a dielectric material according to any one of claims 1 to 12, comprising depositing carbon radicals on a non-catalytic substrate. [Claim 14] The method according to claim 13, comprising repeatedly depositing the carbon radicals to form up to five layers of 2D MAC. [Claim 15] The method according to claim 13 or 14, wherein the deposition of the carbon radicals comprises forming the carbon radicals via photodissociation of a carbon source. [Claim 16] The method according to any one of claims 13 to 15, wherein the deposition of the carbon radicals includes forming the carbon radicals via UV wavelength absorption of a carbon source. [Claim 17] The method according to claim 16, wherein the UV wavelength is 200 to 400 nm. [Claim 18] The method according to any one of claims 15 to 17, wherein the carbon source includes acetylene, methane, acetylene, ethylene, ethanol, propane, naturally attached carbon, or any combination thereof. [Claim 19] The method according to any one of claims 13 to 18, wherein the non-catalytic substrate includes a silicon-based substrate, a carbon-based substrate, a metal-based substrate, an oxide, a transition metal dichalcogenide, maxine, or any combination thereof. [Claim 20] The method according to any one of claims 13 to 19, wherein the non-catalytic substrate includes cobalt, gold, copper, nickel, tungsten, molybdenum, ruthenium, niobium, silicon dioxide, silicon nitride, titanium nitride, tantalum nitride, cobalt oxide, tungsten carbide, germanium, gallium arsenide (GaAs), silver, stainless steel, fernico, manganese, aluminum, or any combination thereof. [Claim 21] The method according to any one of claims 13 to 20, wherein the deposition is carried out in a plasma environment. [Claim 22] The method according to claim 21, further comprising generating the plasma environment before the deposition. [Claim 23] The method according to claim 21 or 22, wherein the plasma environment includes a remotely inductively coupled plasma.

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