Patent Application
20230114933
This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application Nos. 10-2021-0133454, filed on Oct. 7, 2021, and 10-2022-0123480, filed on Sep. 28, 2022, in the Korean Intellectual Property Office, the disclosure of each of which is incorporated by reference herein in its entirety.
The present disclosure relates to a graphene interconnect structure, an electronic device including the graphene interconnect structure, and a method of manufacturing the graphene interconnect structure.
In recent years, the size of semiconductor devices has been gradually reduced to achieve high integration of semiconductor devices. To this end, it is necessary to reduce a line width of the conductive wiring consisting of metal or metal alloy in the interconnect structure. When the line width of the conductive wiring is reduced, current density in the conductive wiring is increased, and as a result, the resistance of the conductive wiring is increased. The increase in resistance of the conductive wiring may cause electromigration of metal or metal alloy atoms constituting the conductive wiring, thereby causing defects in the conductive wiring. To overcome such defects, there is a demand for a graphene interconnect structure having two-dimensional low resistance as a novel material replacing metal or metal alloy, an electronic device including the same, and a method of manufacturing the graphene interconnect structure.
Provided are graphene interconnect structures having a low resistance.
Provided are electronic devices including the graphene interconnect structure.
Provided are methods of manufacturing the graphene interconnect structure.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.
According to an embodiment, a graphene interconnect structure may include: a first oxide dielectric material layer; a second oxide dielectric material layer on a surface of the first oxide dielectric material layer and having a dielectric constant greater than a dielectric constant of the first oxide dielectric material layer; and a graphene layer on a first surface of the second oxide dielectric material layer opposite to a second surface of the second oxide dielectric material layer. The second surface of the second oxide dielectric material layer may be on the first oxide dielectric material layer.
In some embodiments, an areal oxygen density of the first oxide dielectric material layer may be different from an areal oxygen density of the second oxide dielectric material layer.
In some embodiments, a work function of the graphene layer may vary due to a dipole moment generated at an interface between the first oxide dielectric material layer and the second oxide dielectric material layer.
In some embodiments, a specific resistance may be reduced by about 1.1 times to about 10 times according to a change in the work function of the graphene layer in the graphene interconnect structure.
In some embodiments, the first oxide dielectric material layer may include an SiCOH material.
In some embodiments, the first oxide dielectric material layer may include one of tetramethylcyclotetrasiloxane (TOMCATS), octamethylcyclotetrasiloxane (OMCATS), cyclic siloxane 1,1,3,3-tetrahydrido-1,3-disilacyclobutane, 1,1,3,3-tetramethoxy(ethoxy)-1,3 disilacyclobutane, 1,3-dimethyl-1,3-dimethoxy-1,3-disilacyclobutane, 1,3-disilacyclobutane, 1,3-dimethyl-1,3-dihydrido-1,3-disilylcyclobutane, 1,1,3,3-tetramethyl-1,3-disilacyclobutane, 1,1,3,3,5,5-hexamethoxy-1,3,5-trisilane, 1,1,3,3,5,5-hexahydrido-1,3,5-trisilane, 1,1,3,3,5,5-hexamethyl-1,3,5-trisilane, 1,1,1,3,3,3-hexamethoxy(ethoxy)-1,3-disilapropane, 1,1,3,3-tetramethoxy-1-methyl-1,3-disilabutane, 1,1,3,3-tetramethoxy-1,3-disilapropane, 1,1,1,3,3,3-hexahydrido-1,3-disilapropane, 3-(1,1-dimethoxy silaethyl)-1,4,4-trimethoxy-1-methyl-1,4-disilpentane, methoxymethane 2-(dimethoxysilamethyl)-1,1,4-trimethoxy-1,4-disilabutane, methoxymethane 1,1,4-trimethoxy-1,4-disila-2-(trimethoxysilylmethyl) butane, dimethoxymethane, methoxymethane, 1,1,1,5.5.5-hexamethoxy-1,5-disilapentane, 1,1,5,5-tetramethoxy-1,5-disilahexane, 1,1,1,1,4,4,4-hexamethoxy (ethoxy)-1,4-disilylbutane, 1,1,1,4,4,4-hexahydrido-1,4-disilabutane, 1,1,4,4-tetramethoxy(ethoxy)-1,4-dimethyl-1,4-disilabutane, 1,4-bis-trimethoxy(ethoxy)silyl benzene, 1,4-bis-dimethoxymethylsilyl benzene, 1,4-bis-trihydrosilyl benzene, 1,1,1,4,4,4-hexamethoxy (ethoxy)-1,4-disilabut-2-ene, 1,1,1,4,4,4-hexamethoxy(ethoxy)-1,4-disilabut-2-yne, 1,1,3,3-tetramethoxy(ethoxy)-1,3-disilolane, 1,1,3,3-tetramethyl 1,3-disilolane, 1,1,3,3-tetramethoxy(ethoxy)-1,3-disilane, 1,3-dimethoxy(ethoxy)-1,3-dimethyl-1,3-disilane, 1,3-disilane, 1,3-dimethoxy-1,3-disilane, 1,1-dimethoxy (ethoxy)-3.3-dimethyl-1-propyl-3-silabutane, 2-silapropane, or a combination thereof.
In some embodiments, the first oxide dielectric material layer may further include porous SiO2, SiO2 doped with fluorine, or amorphous boron nitride.
In some embodiments, the second oxide dielectric material layer may include a compound represented by Formula 1:
AxOy Formula 1
wherein, in Formula 1, A may be at least one selected from Al, Ti, Zr, Hf, Mg, Si, Ge, Y, Lu, La, and Sr, and 0<x≥2, and 0<y≥3.
In some embodiments, the second oxide dielectric material layer may include at least one of Al2O3, TiO2, ZrO2, HfO2, MgO, SiO2, GeO2, Y2O3, Lu2O3, La2O3, and SrO.
In some embodiments, a thickness of the second oxide dielectric material layer may be in a range of about 0.3 nm to about 5 nm.
In some embodiments, the graphene layer may be directly grown on the surface of the second oxide dielectric material layer opposite to the surface on which the first oxide dielectric material layer is located.
In some embodiments, a grain size of the graphene layer may be in a range of about 10 nm to about 1 μm.
In some embodiments, the graphene layer may include 1 to 7 layers.
According to an embodiment, an electronic device may include: a substrate; and the graphene interconnect structure.
According to an embodiment, a method of manufacturing a graphene interconnect structure may include: preparing a first oxide dielectric material layer; forming a second oxide dielectric material layer by atomic layer deposition (ALD) on a surface of the first oxide dielectric material layer; and directly growing a graphene layer by chemical vapor deposition (CVD) on a surface of the second oxide dielectric material layer. A dielectric constant of the second oxide dielectric material layer may be greater than a dielectric constant of the first oxide dielectric material layer. The second oxide dielectric material layer may include a compound represented by Formula 1:
AxOy Formula 1
wherein, in Formula 1, A may be at least one selected from Al, Ti, Zr, Hf, Mg, Si, Ge, Y, Lu, La, and Sr, and 0<x≥2, and 0<y≥3.
In some embodiments, the first oxide dielectric material layer may include at least one of SiCOH material, porous SiO2, SiO2 doped with fluorine, and amorphous boron nitride.
In some embodiments, the forming the second oxide dielectric material layer by ALD may use a precursor and the precursor may include at least one of (CH3)3Al, TiCl4, trimethoxy(pentamethylcyclopentadienyl)titanium ((CpMe5)Ti(OMe)3), tetrakis(dimethylamino)titanium, Zr[N(CH3)2]4, (dimethylamino)cyclopentadientyl zirconium, ZrCl4, Hf[N(CH3)2]4, Hf(BH4)4, HfCl4, bis(cyclopentadienyl)magnesium (Mg(Cp)2), bis(ethylcyclopentadienyl)magnesium (Mg(CpEt)2), tris(dimethylamino)silane, bis(ethyl-methyl-amino)silane, 1,2-bis(diisopropylamino)disilane, Ge(N, N′—R,R-en)[N(CH3)2]2 (wherein R is isopropyl or t-butyl), tris(N,N′-diisopropyl-formamidinato)yttrium, {Lu[Cp(Si(CH3))2Cl]2 dimer, tris(isopropyl-cyclopentadienyl)lanthanum (La(iPrCp)3), strontium bis(isopropylcyclopentadienyl) (Sr(iPrCp)2), strontium bis(1,2,4-triisopropylcyclopentadienyl) (Sr(1,2,4-iPr3Cp)2), strontium bis(tri(isopropyl)cyclopentadienyl (Sr(C5iPr3H2)2), strontium bis(pentamethylcyclopentadienyl) (Sr(1,2,4-C5Me5)2), strontium bis(n-propyltetramethylcyclopentadienyl) (Sr(nPrMe4Cp)2), and strontium bis(tri-tert-butylcyclopentadienyl) (Sr(tBu3Cp)2).
In some embodiments, in the directly growing of the graphene layer, the CVD may be performed at a temperature in a range of about 250° C. to about 700° C.
According to an embodiment, a graphene interconnect structure may include: a first oxide dielectric material layer; a graphene layer on the first oxide dielectric material layer; and a second oxide dielectric material layer between the first oxide dielectric material layer and the graphene layer. The first oxide dielectric material layer and the second oxide dielectric material layer may contact each other at an interface and may have a structural imbalance at the interface.
In some embodiments, the first oxide dielectric material layer may include a SiCOH material, and the second oxide dielectric material layer may include at least one of Al2O3, TiO2, ZrO2, HfO2, MgO, SiO2, GeO2, Y2O3, Lu2O3, La2O3, and SrO.
In some embodiments, the first oxide dielectric material layer may further include porous SiO2, SiO2 doped with fluorine, or amorphous boron nitride.
In some embodiments, a thickness of the second oxide dielectric material layer may be in a range of about 0.3 nm to about 5 nm.
In some embodiments, the graphene layer may be directly on a surface of the second oxide dielectric material layer, and the graphene layer may include 1 to 7 layers.
The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the presented embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, “at least one of A, B, and C,” and similar language (e.g., “at least one selected from the group consisting of A, B, and C”) may be construed as A only, B only, C only, or any combination of two or more of A, B, and C, such as, for instance, ABC, AB, BC, and AC.
When the terms “about” or “substantially” are used in this specification in connection with a numerical value, it is intended that the associated numerical value includes a manufacturing or operational tolerance (e.g., ±10%) around the stated numerical value. Moreover, when the words “generally” and “substantially” are used in connection with geometric shapes, it is intended that precision of the geometric shape is not required but that latitude for the shape is within the scope of the disclosure. Further, regardless of whether numerical values or shapes are modified as “about” or “substantially,” it will be understood that these values and shapes should be construed as including a manufacturing or operational tolerance (e.g., ±10%) around the stated numerical values or shapes.
Hereinafter, with reference to attached drawings, a graphene interconnect structure and a method of manufacturing the same according to an embodiment will be described in detail. However, these are for illustrative purposes only and are not intended to limit the scope of inventive concepts. The scope of inventive concepts is indicated by the claims rather than by the detailed description.
Like reference numerals in the drawings denotes like components, and sizes of components in the drawings may be exaggerated for clarity and convenience of explanation. In the present specification, the expression “at least one type”, “at least one”, “one type or more”, or “one or more” before the components may supplement the list of all components, and the expression may not mean that the individual components of the description may be supplemented. In the present specification, the term “combination” includes mixtures, alloys, reaction products, or complex forms of one component and another component, unless otherwise stated. It will be further understood that the terms “comprises” and/or “comprising” used herein specify the presence of stated features or components, and they do not preclude the presence of one or more other features or components but add the presence thereof. Unless otherwise stated or otherwise clearly contradicted by context herein, it should be construed to include both the singular and the plural. The term “or” means “and/or” unless otherwise stated.
In the present specification, “one embodiment”, “embodiment”, or the like means that a specific element described in relation to Examples is included in at least one of the Examples described herein, and the specific element may or may not exist in another Example. Also, it should be understood that the described elements may be combined in any suitable manner in various Examples.
Throughout the specification, it will be understood that when a component is referred to as being “on top of” or “on” another component, the component may be directly on the other component or indirectly thereon, while other elements intervening therebetween. Also, it should be understood that the described elements may be combined in any suitable manner in various Examples. Unless otherwise stated, all terms including technical and scientific terms used herein have the same meaning as the terms commonly understood by one of ordinary skill in the art to which the present disclosure pertains.
All patents, patent applications and other references cited are incorporated herein by reference in their entirety. However, to the extent a term herein contradicts or conflicts with a term in the incorporated reference, the term in this specification takes precedence over the conflicting term in the incorporated reference. Although specific embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are not currently anticipated may occur to the applicant or one of ordinary skill in the art. Accordingly, the appended claims, which may be filed and amended, are intended to cover all such alternatives, modifications, variations, improvements, and substantial equivalents.
When an electric field is applied to a dielectric substance, a dielectric material, a dielectric polarization may occur in which polarized molecules are aligned. A degree of polarization may be proportional to the electric field. A degree to which the degree of dielectric polarization is proportional to the applied electric field may be expressed as a permittivity. A permittivity (c) of a dielectric substance or a dielectric material may be referred to as a dielectric constant. Since the term “dielectric constant” as used herein may not be an absolute numerical value, and thus, the expressions may be used interchangeably.
In the present specification, the term “graphene” refers to a polycyclic aromatic molecule in which a plurality of carbon atoms are connected to each other by a covalent bond and arranged in one plane. A plurality of carbon atoms connected by the covalent bond may form a 6-membered ring as a basic repeating unit, but the basic repeating unit may also further include a 5-membered ring and/or a 7-membered ring. The polycyclic aromatic molecules may form a single atom layer in a sheet structure or a network structure arranged in a plane in which a plurality of interconnected plates in the form of small film pieces, or a combination thereof. The polycyclic aromatic molecules may consist of a single layer or a plurality of layers stacked on each other, each having a sheet structure and/or a network structure.
In the present specification, the term “graphene interconnect structure” refers to an interconnect structure including a graphene layer, which itself is used as an interconnect. The graphene layer of the interconnect structure may be distinct from a graphene layer used for a capping layer and/or barrier layer.
As an interconnect structure, metal, for example, copper, has been widely used. When such a metal interconnect structure is fabricated on a nano-scale, a specific resistance of the metal interconnect structure is rapidly increased. This is because, since the metal is a conductor, and electrons are all filled up to a Fermi energy level, a change in specific resistance may not occur.
The present inventors propose a graphene interconnect structure of a novel structure instead of a metal interconnect structure by considering such a point.
As shown in
An areal oxygen density of the first oxide dielectric material layer 10 may be different from an areal oxygen density of the second oxide dielectric material layer 20. An areal oxygen density refers to the number of oxygen atoms present in a unit area. Such a difference in areal oxygen density is due to a structural imbalance between the first oxide dielectric material layer and the second oxide dielectric material layer. Such a structural imbalance may be resolved by migration of oxygen atoms. That is, oxygen atoms may migrate from the first oxide dielectric material layer 10 or the second oxide dielectric material layer 20 having a high areal oxygen density to the second oxide dielectric material layer 20 or the first oxide dielectric material layer 10 having a low areal oxygen density. The migrating oxygen atoms may be in O2− anion form. Migration of oxygen atoms may create oxygen vacancy in the first oxide dielectric material layer 10 or the second oxide dielectric material layer 20 having a high areal oxygen density and excess oxygen in the second oxide dielectric material layer 20 or the first oxide dielectric material layer 10 having a low areal oxygen density. Thus, the second oxide dielectric material layer 20 or the first oxide dielectric material layer 10 having a low areal oxygen density may have a negative charge, and the first oxide dielectric material layer 10 or the second oxide dielectric material layer 20 having a high areal oxygen density may have a positive change. Accordingly, a dipole from a positive charge to a negative change may be generated at an interface between the first oxide dielectric material layer 10 and the second oxide dielectric material layer 20. Such a dipole may raise or lower a Fermi energy level (EF) of the second oxide dielectric material layer 20 at an interface between the first oxide dielectric material layer 10 and the second oxide dielectric material layer 20. A work function of the graphene layer 30 on the second oxide dielectric material layer 20 may change.
That is, a work function of the graphene layer 30 may vary due to a dipole moment generated at an interface between the first oxide dielectric material layer 10 and the second oxide dielectric material layer 20. The change in work function of the graphene layer 30 may influence to a specific resistance of the graphene interconnect structure 100. A specific resistance of the graphene interconnect structure 100 may be reduced by about 1.1 times to about 10 times according to a change in the work function of the graphene layer 30 in the graphene interconnect structure 100.
As shown in
As shown in
The first oxide dielectric material layer 10 may include an SiCOH material. The SiCOH material may include Si, C, O, or H atoms, and these atoms in the dielectric material may be bound via a covalent bond to form Si—O, Si—C, Si—H, C—H, or C—C. The SiCOH material may be a dielectric material having a low dielectric constant of about 2.8 or less. The SiCOH material may be porous or non-porous. The SiCOH material may form a two-dimensional network of covalent bonds. For example, the SiCOH material may have about 5 atom % to about 40 atom % of Si; about 5 atom % to about 45 atom % of C; about 0 atom % to about 50 atom % of O; and about 5 atom % to about 55 atom % of H.
The first oxide dielectric material layer 10 may include tetramethylcyclotetrasiloxane (TOMCATS), octamethylcyclotetrasiloxane (OMCATS), cyclic siloxane 1,1,3,3-tetrahydrido-1,3-disilacyclobutane, 1,1,3,3-tetramethoxy(ethoxy)-1,3 disilacyclobutane, 1,3-dimethyl-1,3-dimethoxy-1,3-disilacyclobutane, 1,3-disilacyclobutane, 1,3-dimethyl-1,3-dihydrido-1,3-disilylcyclobutane, 1,1,3,3-tetramethyl-1,3-disilacyclobutane, 1,1,3,3,5,5-hexamethoxy-1,3,5-trisilane, 1,1,3,3,5,5-hexahydrido-1,3,5-trisilane, 1,1,3,3,5,5-hexamethyl-1,3,5-trisilane, 1,1,1,3,3,3-hexamethoxy(ethoxy)-1,3-disilapropane, 1,1,3,3-tetramethoxy-1-methyl-1,3-disilabutane, 1,1,3,3-tetramethoxy-1,3-disilapropane, 1,1,1,3,3,3-hexahydrido-1,3-disilapropane, 3-(1,1-dimethoxy-1-silaethyl)-1,4,4-trimethoxy-1-methyl-1,4-disilpentane, methoxymethane 2-(dimethoxysilamethyl)-1,1,4-trimethoxy-1,4-disilabutane, methoxymethane 1,1,4-trimethoxy-1,4-disila-2-(trimethoxysilylmethyl) butane, dimethoxymethane, methoxymethane, 1,1,1,5.5.5-hexamethoxy-1,5-disilapentane, 1,1,5,5-tetramethoxy-1,5-disilahexane, 1,1,1,1,4,4,4-hexamethoxy (ethoxy)-1,4-disilylbutane, 1,1,1,4,4,4-hexahydrido-1,4-disilabutane, 1,1,4,4-tetramethoxy(ethoxy)-1,4-dimethyl-1,4-disilabutane, 1,4-bis-trimethoxy(ethoxy)silyl benzene, 1,4-bis-dimethoxymethylsilyl benzene, 1,4-bis-trihydrosilyl benzene, 1,1,1,4,4,4-hexamethoxy (ethoxy)-1,4-disilabut-2-ene, 1,1,1,4,4,4-hexamethoxy(ethoxy)-1,4-disilabut-2-yne, 1,1,3,3-tetramethoxy(ethoxy)-1,3-disilolane, 1,1,3,3-tetramethyl 1,3-disilolane, 1,1,3,3-tetramethoxy(ethoxy)-1,3-disilane, 1,3-dimethoxy(ethoxy)-1,3-dimethyl-1,3-disilane, 1,3-disilane, 1,3-dimethoxy-1,3-disilane, 1,1-dimethoxy (ethoxy)-3.3-dimethyl propyl-3-silabutane, 2-silapropane, or a combination thereof.
The first oxide dielectric material layer 10 may further include porous SiO2, SiO2 doped with fluorine, or amorphous boron nitride. For example, the first oxide dielectric material layer 10 may be the porous SiO2. The porous SiO2 may have nanopores. A diameter of the nanopores may be in a range of about 0.1 nm to about 50 nm. A porosity of the porous SiO2 may be in a range of about 0.5% to about 50%, based on the total volume.
The second oxide dielectric material layer 20 may include a compound represented by Formula 1:
AxOy Formula 1
wherein, in Formula 1, A may be at least one selected from Al, Ti, Zr, Hf, Mg, Si, Ge, Y, Lu, La, and Sr, and 0<x≥2, and 0<y≥3.
The second oxide dielectric material layer 20 may include at least one oxide selected from Al2O3, TiO2, ZrO2, HfO2, MgO, SiO2, GeO2, Y2O3, Lu2O3, La2O3, and SrO. The second oxide dielectric material layer 20 may further include a dopant, according to a need. Examples of the dopant may include at least one of Si, Al, Zr, Y, La, Gd, Sr, and Hf, but embodiments are not limited thereto.
A thickness of the second oxide dielectric material layer 20 may be in a range of about 0.3 nm to about 5 nm. When a thickness of the second oxide dielectric material layer 20 is within this range, a dipole generated at an interface between the first oxide dielectric material layer 10 and the second oxide dielectric material layer 20 may be effectively transferred to the graphene layer 30 to thereby reduce the specific resistance. Accordingly, RC delay may be limited and/or prevented, and reliability may be secured.
The graphene layer 30 may be directly grown on the surface of the second oxide dielectric material layer 20 opposite to the surface on which the first oxide dielectric material layer 10 is located.
A grain size of the graphene layer 30 may be in a range of about 10 nm to about 1 μm.
The graphene layer 30 may be directly grown on the opposite surface of the second oxide dielectric material layer 20 by chemical vapor deposition (CVD). The graphene layer 30 may have a sufficiently low specific resistance to be used as an interconnect structure. In addition, the graphene layer 30 may have excellent processability, as compared with the graphene layer transferred after growth using a catalyst on a separate substrate, and a graphene layer may be effectively realized even in a structure with a narrow line width.
The graphene layer 30 may include 1 to 7 layers.
An electronic device according to one or more embodiments may include: a substrate; and the graphene interconnect structure.
The substrate may include at least one of a Group IV semiconductor material, a semiconductor compound, an insulating material, and a metal. For example, the substrate may include a Group IV semiconductor material, such as Si, Ge, or Sn. In some embodiments, for example, a substrate may include at least one of Si, Ge, C, Zn, Cd, Al, Ga, In, B, C, N, P, S, Se, As, Sb, Te Ta, Ru, Rh, Ir, Co, Ta, Ti, W, Pt, Au, Ni, and Fe. For example, the substrate may include Si, Ge, SiC, SiGe, SiGeC, Ge alloy, GaAs, InAs, or InP. The substrate may include a single layer or a plurality of layers in which different materials are stacked.
For example, the substrate may include a silicon-on-insulator (SOI) substrate or a silicon germanium-on-insulator (SGOI) substrate. For example, the substrate may further include N or F as a SiCOH-based composition and may include pores for reducing a permittivity. The substrate may further include a dopant.
The substrate may include at least one semiconductor device. For example, semiconductor device may include at least one of a transistor, a capacitor, a diode, and a resistor. For example, the semiconductor device may be a transistor. However, the semiconductor device is not particularly limited thereto, and any suitable semiconductor device available in the art may be used.
Referring to
A source electrode 651 and a drain electrode 652 are provided on the upper surface of the graphene layer 630 and spaced apart from each other. A gate insulating layer 670 may be provided on the graphene layer 630 between the source electrode 651 and the drain electrode 652, and a gate electrode 660 may be provided on the gate insulating layer 670. The gate electrode 660 may be spaced apart from the source electrode 651, drain electrode 652, and graphene layer 630 with the gate insulating layer 670 therebetween.
The electronic device 600a may further include an insulating layer 685, such as silicon oxide, covering the source electrode 651, gate insulating layer 670, gate electrode 660, and drain electrode 652. The data storage DS (e.g., capacitor) may be on the insulating layer 685. A contact 675 including an electrically conductive material, such as a metal or metal alloy, may connect the data storage DS to the drain electrode 652.
Referring to
Referring to
Referring to
A gate insulating layer 770 may be provided on the first oxide dielectric material layer 710 and the gate insulating layer 770 may extend over the graphene layer 730 and second oxide dielectric material layer 720. A source electrode 751 and a drain electrode 752 are provided on the gate insulating layer 770 and spaced apart from each other. The gate insulating layer 770 may extend between the first oxide dielectric material layer 710 and both the source electrode 751 and the drain electrode 752. The graphene layer 730 may be configured to operate as a gate electrode of the electronic device 770a. Although not illustrated, a conductive material such as a metal or metal alloy may be formed in the trench of the first oxide dielectric material layer 710 and may be surrounded by the graphene layer 730.
The electronic device 700a may further include an insulating layer 785, such as silicon oxide, covering the source electrode 751, gate insulating layer 770, and drain electrode 752. The data storage DS (e.g., capacitor) may be on the insulating layer 785. A contact 775 including an electrically conductive material, such as a metal or metal alloy, may connect the data storage DS to the drain electrode 752.
Referring to
A conductive layer 790 may electrically connect the graphene interconnect structures to each other by extending over the first oxide dielectric material layer 710 and contacting an upper surface of the graphene layers 730 in the respective graphene interconnect structures. The conductive layer 790 may include a conductive material such as a metal, a metal alloy, or a doped semiconductor.
The electronic device 700b may provide a resistor. Alternatively, in some embodiments, the electronic device 700b may provide a diode structure if the conductive layer 790 includes a first portion and a second portion of opposite conductivity types like the diode structure 680 described in
According to an aspect of still another embodiment, a method of manufacturing a graphene interconnect structure may include: preparing the first oxide dielectric material layer 10; forming the second oxide dielectric material layer 20 having a dielectric constant greater than that of the first oxide dielectric material layer 10 by atomic layer deposition (ALD) on a surface of the first oxide dielectric material layer 20; and directly growing the graphene layer 30 by chemical vapor deposition (CVD) on a surface of the second oxide dielectric material layer 20 opposite to the surface on which the first oxide dielectric material layer 10 is located, wherein the second oxide dielectric material layer 20 may include a compound represented by Formula 1:
AxOy Formula 1
wherein, in Formula 1, A may be at least one selected from Al, Ti, Zr, Hf, Mg, Si, Ge, Y, Lu, La, and Sr, and 0<x≥2, and 0<y≥3.
The first oxide dielectric material layer 10 may be prepared. The first oxide dielectric material layer may include at least one selected from an SiCOH material, porous SiO2, SiO2 doped with fluorine, and amorphous boron nitride. The first oxide dielectric material layer 10 may be manufactured by chemical vapor deposition (CVD), high-density plasma CVD (HDPCVD), plasma enhanced CVD (PECVD), pulsed plasma enhanced CVD (pulsed PECVD), spin-on application, or any other suitable method.
For example, when the first oxide dielectric material layer 10 is an SiCOH material, a first precursor (liquid, gas, steam, or vapor) including Si, C, O, and H atoms and an inert carrier such as He or Ar may be provided to a PECVD reactor to mix the precursor with an oxidizing agent of O2, CO2, or a combination thereof, thereby preparing the first oxide dielectric material layer 10. In addition to the first precursor, a second precursor (liquid, gas, steam, or vapor) including C, H, optionally O, F, and N atoms may be used. Optionally, a third precursor (liquid, gas, steam, or vapor) including Ge may also be used.
The first precursor may be selected from organic moleculec having a cyclic structure including an SiCOH component such as 1,3,5,7-tetramethylcyclotetrasiloxane (“TMCTS” or “C4H16O4Si4”), octamethylcyclotetrasiloxane (OMCTS), diethoxymethylsilane (DEMS), dimethyldimethoxysilane (DMDMOS), or siloxane. The second precursor may be selected from at least one ring present in a molecule such as cyclopentene oxide (C5H8O or CPO) or a hydrocarbon molecule having a branched chain attached to a ring. The third precursor may be formed from a Ge hydride or any other reactant including a Ge source. The PECVD condition may vary depending on the SiCOH material, and for example, a substrate temperature may be in a range of about 300° C. to about 425° C., a high frequency current density may be in a range of about 0.1 W/cm2 to about 1.5 W/cm2, a flow rate of the first precursor (liquid) may be in a range of about 100 mg/min to about 5,000 mg/min, optionally, a flow rate of the second precursor (liquid) may be in a range of about 50 mg/min to about 10,000 mg/min, optionally, a flow rate of the third precursor (liquid) may be in a range of about 25 mg/min to about 4,000 mg/min, optionally, a flow rate of an inert carrier gas such as He (and/or Ar) may be in a range of about 50 sccm to about 5,000 sccm, a reactor pressure may be in a range of about 1,000 mTorr to about 7,000 mTorr, and a high frequency RF power may be in a range of about 75 W to about 1,000 W. A flow rate of an oxidizing agent added to the PECVD reactor may be in a range of about 10 sccm to about 1,000 sccm. Examples of liquid precursors are described herein, however, a gas precursor such as trimethylsilane may also be used.
The second oxide dielectric material layer 20 having a dielectric constant greater than that of the first oxide dielectric material layer 10 may be formed by atomic layer deposition (ALD) on a surface of the first oxide dielectric material layer 10. A precursor for forming the second oxide dielectric material layer 20 by ALD may include at least one selected from (CH3)3Al, TiCl4, trimethoxy(pentamethylcyclopentadienyl)titanium ((CpMe5)Ti(OMe)3), tetrakis(dimethylamino)titanium, Zr[N(CH3)2]4, (dimethylamino)cyclopentadientyl zirconium, ZrCl4, Hf[N(CH3)2]4, Hf(BH4)4, HfCl4, bis(cyclopentadienyl)magnesium (Mg(Cp)2), bis(ethylcyclopentadienyl)magnesium (Mg(CpEt)2), tris(dimethylamino)silane, bis(ethyl-methyl-amino)silane, 1,2-bis(diisopropylamino)disilane, Ge(N, N′—R,R-en)[N(CH3)2]2 (wherein R is isopropyl or t-butyl), tris(N,N′-diisopropyl-formamidinato)yttrium, {Lu[Cp(Si(CH3))2Cl]2 dimer, tris(isopropyl-cyclopentadienyl)lanthanum (La(iPrCp)3), strontium bis(isopropylcyclopentadienyl) (Sr(iPrCp)2), strontium bis(1,2,4-triisopropylcyclopentadienyl) (Sr(1,2,4-iPr3Cp)2), strontium bis(tri(isopropyl)cyclopentadienyl (Sr(C5iPr3H2)2), strontium bis(pentamethylcyclopentadienyl) (Sr(1,2,4-C5Me5)2), strontium bis(n-propyltetramethylcyclopentadienyl) (Sr(nPrMe4Cp)2), and strontium bis(tri-tert-butylcyclopentadienyl) (Sr(tBu3Cp)2). As a reaction gas, an oxygen-containing precursor such as pure H2O steam may be used. The atomic layer deposition may be performed by a cycle including: providing a precursor for forming the second oxide dielectric material layer; a first purging for discharging a reaction residue of the precursor for forming the second oxide dielectric material layer; providing an oxygen-containing precursor (e.g., pure H2O steam); and a second purging for discharging a reaction residue of the the oxygen-containing precursor (e.g., pure H2O steam). The number of cycling may be determined according to a need for formation of the second oxide dielectric material layer. The atomic layer deposition may be performed at a temperature in a range of about 200° C. to about 900° C.
The second oxide dielectric material layer 20 may include at least one oxide selected from Al2O3, TiO2, ZrO2, HfO2, MgO, SiO2, GeO2, Y2O3, Lu2O3, La2O3, and SrO.
A thickness of the second oxide dielectric material layer 20 may be in a range of about 0.3 nm to about 5 nm. When a thickness of the second oxide dielectric material layer 20 is within this range, a dipole generated at an interface between the first oxide dielectric material layer 10 and the second oxide dielectric material layer 20 may be effectively transferred to the graphene layer 30 to thereby reduce the specific resistance. Accordingly, RC delay may be limited and/or prevented, and reliability may be secured.
The graphene layer 30 may be directly grown by CVD on a surface of the second oxide dielectric material layer 20 opposite to the surface on which the first oxide dielectric material layer 10 is formed. To allow the graphene layer 30 to directly be grown, a reaction gas may be injected into a reaction chamber. The reaction gas may include a carbon source. The carbon source may include at least one of, for example, a hydrocarbon gas and vapor of liquid precursor including carbon. Here, the hydrocarbon gas may include, for example, methane gas, ethylene gas, acetylene gas, or propylene gas. The liquid precursor including carbon may include, for example, benzene, toluene, xylene, anisol, hexane, octane, isopropyl alcohol, or ethanol. However, these carbon source materials are illustrative only, and various materials, in addition to the carbon source materials, may be used as carbon source materials.
The reaction gas may further include an inert gas and hydrogen gas. The inert gas may include at least one of, for example, argon gas, neon gas, nitrogen gas, helium gas, krypton gas, and xenon gas.
To allow the graphene layer 30 to be directly grown, for example, a mixed gas of a carbon source gas, an inert gas, and a hydrogen gas may be used as a reaction gas. A mixed ratio of the reaction gas injected into the reaction chamber may vary depending on the growing condition of the graphene layer 30.
In the case of directly growing the graphene layer 30 using the PECVD process, power for plasma generation may be applied to the inside of the reaction chamber from a plasma power source. For example, plasma power applied to the growing process of the graphene layer 30 may be 600 W or less, for example, 300 W or less. The plasma power applied to the growing process of the graphene layer 30 may be various types of powers.
Examples of the plasma power may include an RF plasma-generating apparatus or an MW plasma-generating apparatus. The RF plasma-generating apparatus may generate, for example, RF plasma having a frequency in a range of about 3 MHz to about 100 MHz, and the MW plasma-generating apparatus may generate, for example, MW plasma having a frequency in a range of about 0.7 GHz to about 2.5 GHz. However, the frequency ranges are illustrative only, and other frequency ranges may also be used. As a plasma power, a plurality of RF plasma-generating apparatuses or a plurality of MW plasma-generating apparatuses may be used.
When power for plasma generation is applied to the inside of the reaction chamber from the plasma power source, plasma of the reaction gas may be generated inside the reaction chamber. In addition, plasma of the doping gas may be generated inside the reaction chamber.
The CVD may be performed at a temperature in a range of about 250° C. to about 700° C. When the CVD is performed at a temperature lower than 250° C., it may be difficult to decompose the carbon source, and when the CVD is performed at a temperature higher than 700° C., the electronic device may not operate upon application thereof.
A grain size of the graphene layer 30 may be in a range of about 10 nm to about 1 μm.
The graphene layer 30 may be directly grown on the opposite surface of the second oxide dielectric material layer 20 by chemical vapor deposition (CVD). The graphene layer 30 may have a sufficiently low specific resistance to be used as an interconnect structure. In addition, the graphene layer 30 may have excellent processability, as compared with the graphene layer transferred after growth using a catalyst on a separate substrate, and a graphene layer may be effectively realized even in a structure with a narrow line width.
The graphene layer 30 may include 1 to 7 layers.
According to an aspect, the graphene interconnect structure may include: a first oxide dielectric material layer; a second oxide dielectric material layer on a surface of the first oxide dielectric material layer and having a dielectric constant greater than that of the first oxide dielectric material layer; and a graphene layer on a surface of the second oxide dielectric material layer opposite to the surface on which the first oxide dielectric material layer is located. An areal oxygen density of the first oxide dielectric material layer may be different from an areal oxygen density of the second oxide dielectric material layer. Accordingly, a work function of the graphene layer may vary due to a dipole moment generated at an interface between the first oxide dielectric material layer and the second oxide dielectric material layer. As a result, a specific resistance of the graphene interconnect structure may be reduced.
It should be understood that 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 typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill 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 following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0133454 | Oct 2021 | KR | national |
| 10-2022-0123480 | Sep 2022 | KR | national |
