Method for depositing a barrier layer on a metal surface

Abstract

Several methods of enhancing selective deposition are described. In some embodiments, a barrier layer is deposited on the metal surface prior to deposition of the dielectric. In some embodiments, the metal surface is functionalized to enhance or reduce its reactivity.

Description

[0001] This application is a divisional application of patent application No. 201880047381.5, filed on July 17, 2018, entitled "Method for depositing a barrier layer on a metal surface". Technical Field

[0002] Embodiments of this disclosure relate to methods for depositing a barrier layer on a metal surface. In particular, embodiments of this disclosure relate to methods for depositing a barrier layer on a metal surface to facilitate the deposition of silicon nitride only on a dielectric surface. Background Technology

[0003] The semiconductor industry faces numerous challenges in its pursuit of device miniaturization, which involves rapidly scaling down nanoscale features. These challenges include introducing complex manufacturing steps, such as multiple lithography steps, and integrating high-performance materials. To maintain the pace of device miniaturization, selective deposition has emerged as a promising approach, as it has the potential to eliminate costly lithography steps by simplifying the integration process.

[0004] Selective deposition of materials can be achieved in a wide variety of ways. Chemical precursors can selectively react with one surface relative to another (metal or dielectric). Process parameters such as pressure, substrate temperature, precursor partial pressure, and / or gas flow rate can be controlled to modulate the chemical kinetics of the reaction on a specific surface. Another possible approach involves surface pretreatment of film deposition precursors that can be used to activate or deactivate the surface of interest.

[0005] There is a continuous need for methods to improve deposition selectivity in this technology. Summary of the Invention

[0006] One or more embodiments of this disclosure relate to a method for selectively depositing a barrier layer. The method includes exposing a substrate having a metal surface and a dielectric surface to a silane to selectively form a barrier layer on the metal surface, the silane comprising at least one compound of the general formula SiH3R, wherein R is an alkyl, perfluorinated alkyl, alkenyl, or alkynyl group selected from C4 to C20.

[0007] Additional embodiments of this disclosure relate to a method for selectively depositing a barrier layer. The method includes exposing a substrate having a metal surface and a dielectric surface to an alkyne and a nitrogen reactant to selectively form a barrier layer on the metal surface, the nitrogen reactant comprising an azide or a nitrile oxide.

[0008] Further embodiments of this disclosure relate to a method for selectively depositing a barrier layer. The method includes exposing a substrate having a metal surface and a dielectric surface to an epoxide to selectively form a barrier layer on the metal surface. Attached Figure Description

[0009] The above brief summary of the detailed features of this disclosure can be understood in a detailed manner, and a more specific description of this disclosure can be obtained by referring to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only typical embodiments of this disclosure and should not be construed as limiting the scope of this disclosure, as other equivalent and effective embodiments are permissible.

[0010] Figure 1 This disclosure illustrates a series of general structures relating to azide and alkyne blocking agents of a possible number or reactive groups according to one or more embodiments of the present disclosure;

[0011] Figure 2 A schematic diagram illustrating a reaction in which a monomer, according to one or more embodiments of the present disclosure, selectively forms a polymeric network on a metal surface in the presence of the metal surface and in the presence of a cyclization reaction;

[0012] Figure 3 The present disclosure illustrates a general process flow for selectively depositing a polymer barrier layer on a metal surface and selectively depositing a dielectric film on a dielectric surface, according to one or more embodiments of the present disclosure.

[0013] Figure 4 Examples of processes for removing polymer barrier layers using oxygen-based and hydrogen-based remote plasmas, according to one or more embodiments of this disclosure, are shown; and

[0014] Figure 5 A process flow for a selective deposition process according to one or more embodiments of the present disclosure is shown. Detailed Implementation

[0015] Embodiments of this disclosure provide various methods for depositing barrier layers on metal surfaces. Embodiments of this disclosure demonstrate several methods for depositing barrier layers that can be used individually or in combination.

[0016] Embodiments of this disclosure provide a method for advantageously depositing a dielectric material (e.g., SiN) on a dielectric surface, the method being achieved by blocking the deposition of the dielectric material on the metal surface via a barrier layer deposited on the metal surface.

[0017] As used herein, "substrate surface" refers to a portion of the material surface formed on the substrate on which the film treatment is performed, or any portion of the substrate. For example, depending on the application, substrate surfaces on which treatment can be performed include materials such as silicon, silicon oxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire; and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials. The substrate is not limited to semiconductor wafers. The substrate may be exposed to pretreatment processes such as polishing, etching, reduction, oxidation, hydroxideing, annealing, UV curing, electron beam curing, and / or baking. In addition to performing the film treatment directly on the surface of the substrate itself, any of the film treatment steps disclosed in this disclosure may also be performed on an underlying layer formed on the substrate, as will be disclosed in more detail below, and the term "substrate surface" is intended to include such an underlying layer as understood in the context. Thus, for example, when a film / layer or a portion of a film / layer has been deposited on the substrate surface, the exposed surface of a newly deposited film / layer becomes the substrate surface. The substrate can have various sizes, such as wafers with a diameter of 200 mm or 300 mm, and rectangular or square plates. In some embodiments, the substrate comprises rigid discrete materials.

[0018] As used herein, "atomic layer deposition" or "cyclic deposition" refers to a process involving the sequential exposure of two or more reactive compounds to deposit a material layer on a substrate surface. As used in this specification and the appended claims, the terms "reactive compound," "reactive gas," "reactive species," "precursor," "processing gas," and similar terms are used interchangeably to mean a substance having a species capable of reacting with the substrate surface or a material on the substrate surface in a surface reaction (e.g., chemisorption, oxidation, reduction, cycloaddition). The substrate or a portion thereof is sequentially exposed to the two or more reactive compounds, which are introduced into the reaction region of a processing chamber.

[0019] Embodiments of this disclosure advantageously provide methods for surface pretreatment, such as selectively blocking metal surfaces (including, but not limited to, copper, cobalt, tungsten, tantalum, tantalum nitride, tantalum oxide, titanium, titanium oxide, titanium nitride, ruthenium, ruthenium oxide, and iridium). Some embodiments advantageously provide methods for selectively growing dielectric materials on dielectric surfaces, such as SiO2, SiN, SiCON, SiCO, etc. Some embodiments advantageously provide methods for selectively blocking surface deposition using epoxide surface reactions.

[0020] In some embodiments, metal silicides are selectively formed on metal surfaces preferentially over dielectric surfaces. As used in this specification and the appended claims, the term "selectively...preferring" or similar expressions mean that the material is deposited on the stated surface to a greater extent than on another surface. In some embodiments, "selective" means that the material is formed on the selective surface at a rate greater than or equal to about 10, 15, 20, 25, 30, 35, 40, 45, or 50 times the formation rate on non-selected surfaces. In some embodiments, trihydridosilanes containing long alkyl chains (RSiH3, where R = C4-C20) are used as barrier molecules and react with metal surfaces (including but not limited to Cu, Co, W, and TiN) in solution or in the gas phase. In some embodiments, the metal surface is cleaned before reacting with the barrier molecule. The organosilane reacts with metal surfaces selectively preferentially over dielectric surfaces (e.g., SiO2) via a silane head group. The organic portion of silane acts as a hydrophobic protective layer, thus preventing the growth of subsequent dielectric layers (such as SiN) on the metal, thereby enabling the selective deposition of dielectrics on the dielectric surface.

[0021] One or more embodiments of this disclosure relate to a method of selectively depositing a barrier layer on a metallic surface of a substrate having a metallic surface and a dielectric surface. The method includes exposing the substrate to a silane comprising at least one compound of the general formula SiH3R, wherein R is an alkyl, perfluorinated alkyl, alkenyl, or alkynyl group selected from C4 to C20. As used in this manner, the letter “C” followed by a numerical value (e.g., “C4”) indicates that the substituent comprises a specified number of carbon atoms (e.g., C4 comprises four carbon atoms). In some embodiments, the substituent may be a linear group (e.g., n-butyl), a branched group (e.g., tert-butyl), or a cyclic group (e.g., cyclohexyl).

[0022] The dielectric surface of the substrate may include any suitable dielectric material. Suitable dielectric materials include, but are not limited to, oxides (e.g., silicon oxide) and high-k dielectrics. In some embodiments, the dielectric surface is substantially composed of silicon oxide. As used in this manner, the term "substantially composed of" means, on an area basis, that the surface has more than or equal to about 95%, 98%, or 99% of the material described above.

[0023] The metal surface of the substrate may comprise any suitable metallic material. Suitable metallic materials include, but are not limited to, metals, metal nitrides, metal alloys, and other conductive materials. In some embodiments, the metal surface comprises one or more of cobalt, tungsten, or titanium nitride. In some embodiments, the metal surface is substantially composed of cobalt. In some embodiments, the metal surface is substantially composed of tungsten. In some embodiments, the metal surface is substantially composed of titanium nitride.

[0024] The silane exposed to the substrate may comprise any suitable trihydrosilane. In some embodiments, the silane comprises at least one compound of the general formula SiH3R, wherein R is an alkyl, perfluorinated alkyl, alkenyl, or alkynyl group selected from C4 to C20. In some embodiments, the C4 to C20 alkyl group is substantially composed of a silicon-carbon bond, several carbon-carbon single bonds, and several carbon-hydrogen bonds. In some embodiments, the C4 to C20 perfluorinated alkyl group is substantially composed of a silicon-carbon bond, several carbon-carbon single bonds, and several carbon-fluorine bonds. In some embodiments, the C4 to C20 alkenyl group is substantially composed of a silicon-carbon bond, several carbon-carbon single bonds, at least one carbon-carbon double bond, and several carbon-hydrogen bonds. In some embodiments, the C4 to C20 alkynyl group is substantially composed of a silicon-carbon bond, several carbon-carbon single bonds, at least one carbon-carbon triple bond, and several carbon-hydrogen bonds. In some embodiments, the C4 to C20 group includes one or more halogen atoms and / or a hydrophobic moiety.

[0025] In some embodiments, the silane comprises C4 to C20 alkyl groups. In some embodiments, the silane comprises dodecylsilane (C4 to C20 alkyl groups). 12 H 25 (SiH3). In some embodiments, the silane is essentially composed of dodecylsilane.

[0026] In some embodiments, the silane groups crosslink with each other after deposition. In some embodiments, the barrier layer is substantially free of crosslinks between silane groups. As used herein, the term "substantially non-crosslinked" means that there is less than or equal to about 5%, 2%, or 1% crosslinking on a surface area basis.

[0027] In some embodiments, the substrate is cleaned before being exposed to silane. In some embodiments, only the metal surfaces of the substrate are cleaned before the substrate is exposed to silane. In some embodiments, the metal surfaces of the substrate or the substrate itself are cleaned with hydrogen plasma. In some embodiments, the hydrogen plasma is conductive-coupled plasma (CCP). In some embodiments, the hydrogen plasma is inductively coupled plasma (ICP). In some embodiments, the hydrogen plasma includes H2 plasma.

[0028] In some embodiments, after the barrier layer is deposited, a dielectric layer is selectively deposited on the dielectric surface. In some embodiments, the dielectric layer comprises silicon nitride. The deposition of silicon nitride can be performed via any suitable process. Suitable processes may include exposing the substrate to silicon halides and ammonia. Suitable silicon halides include, but are not limited to: dichlorosilane (DCS), trichlorosilane (TCS), tetrachlorosilane (SiCl4), tetrabromosilane (SiBr4), tetraiodosilane (SiI4), and hexachlorosilane (HCDS).

[0029] In some embodiments, the substrate is repeatedly exposed to the silane after the dielectric layer is deposited to regenerate the barrier layer. In some embodiments, the dielectric layer is deposited again after the barrier layer is regenerated. In some embodiments, the substrate is repeatedly exposed to the silane and a silicon nitride layer is deposited until the silicon nitride layer has reached a predetermined thickness.

[0030] After a certain number of deposition cycles, or after a film thickness has been achieved, one or more exposures to the surface barrier chemicals, or regeneration of the barrier layer, can be performed. In some embodiments, before barrier layer regeneration, a silicon nitride layer is deposited to a thickness of approximately [thickness value missing]. to approximately The range, or about to approximately The range, or about to approximately The range. In some embodiments, the substrate is repeatedly exposed to the silane and silicon nitride is deposited until the silicon nitride layer has a density greater than or equal to the specified range. or Until the thickness reaches [a certain value].

[0031] Example

[0032] The metal surface was cleaned using 100-watt hydrogen plasma for 2 to 10 minutes to reduce the concentration of native oxides. Silane was deposited at a substrate temperature of 200°C. Water contact angle (WCA) measurements were initially used to investigate the formation of metal silicides. A higher contact angle indicates a hydrophobic surface (i.e., silicide formation). WCA indicated that SiO2 was not blocked by dodecylsilane (DDS, R = C12), while the metal surface (i.e., Co, W, and TiN) was blocked. The hydrogen plasma treatment used for surface cleaning facilitated the formation of metal silicides.

[0033] Thermal and chemical stability tests indicate that the DDS barrier on the metal is stable up to 200°C for W and TiN, and stable up to 330°C for Co. The DDS self-assembled monolayer (SAM) is resistant to silicon halides (dichlorosilane (DCS), trichlorosilane (TCS), tetrachlorosilane (SiCl4), tetrabromosilane (SiBr4), tetraiodosilane (SiI4)) and NH3, as described above in the ALD used for SiN.

[0034] WCA studies of SiN of different thicknesses deposited on DDS SAM show that when When SAM is regenerated after SiN growth, a minimum thickness of up to [missing information] can be achieved on Co, W, and TiN surfaces. The selectivity is improved. The selectivity can be extended by repeating the number of regeneration cycles between SiN formations. It was observed that the DDS-treated substrate exhibited almost no SiN growth (due to the oxidation of SiN to SiO2 caused by air exposure), while the untreated substrate exhibited approximately... SiN growth.

[0035] In some embodiments, substituted azide or nitrile oxide and alkyne react in the presence of a copper surface to form a barrier layer. This reaction forms surface-bound species that have the potential to inert the newly functionalized copper surface or promote the reactivity of the introduced film deposition precursor. For example, azide or nitrile oxide reacts with alkyne in the presence of copper metal to form triazole or isoxazole (in the case of azide or nitrile oxide, respectively). In some embodiments, trimethylsilyl azide and trimethylsilyl acetylene react in the presence of a copper metal surface to form the resulting surface-bound triazole. In some embodiments, the substituted azide and alkyne precursor are sequentially introduced onto the substrate in the gas phase.

[0036] In some embodiments, the substituted azide or nitrile oxide reacts with the substituted alkyne in the presence of a metal surface. The number N of reactive substituents on each molecule (azide, nitrile oxide, and alkyne) can range from 1 to 4 reactive groups. In some embodiments, the number of reactive groups is greater than 1.

[0037] refer to Figure 1 The possible number or reactive groups associated with azides and alkynes are shown as a series of general structures. The wavy lines holding the groups together can be any molecular chain that holds the reactive groups together (based on carbon, silicon, or even other elements such as boron, phosphorus, nitrogen, oxygen, and sulfur).

[0038] Unrestricted by theory, it is believed that when these monomers are present on a metal surface, these moieties will undergo cyclization reactions to form a polymer network on the metal surface, but not on the dielectric surface, such as... Figure 2 The diagram illustrates that the bonding of the polymer network to the metal surface is believed to occur through the interaction of π electrons from nitrogen substituents and heterocycles on the polymer surface with the metal surface.

[0039] Figure 3 This diagram illustrates a general process flow for selective deposition according to some embodiments of the present disclosure. The process begins by introducing acetylene-based (e.g., alkyne) and azide-based monomers to a substrate via a solution phase, a pure liquid phase (neat), or a gas phase method at a temperature ranging from about 20°C to about 600°C. In some embodiments, the metal surface is a pure metal surface without any oxides. After the monomers are introduced, a polymer network begins to form on the metal surface via metal-catalyzed triazole formation. After the metal-catalyzed polymerization is complete, unreacted monomers can be removed by washing these surfaces with a solvent (if carried out in the solution phase) or by flushing with an inert gas inside the reactor. A film nucleated only on the dielectric can then be deposited.

[0040] After the process is completed, the polymer layer can be removed using a selective etching process. It is known that oxygen-based and fluorine-based etching will etch the carbon-based film, similar to the barrier layer deposited therein. Figure 4 An example of polymer removal via oxygen-based remote plasma is illustrated. In this example, the polymer is removed via oxygen-based remote plasma etching, which removes the polymer but oxidizes the metal surface. To restore the original metal surface, the metal oxide can be reduced back to metal. In some embodiments, the reduction includes exposure to H2 and NH3 plasma and / or H2 and NH3 thermal annealing.

[0041] In some implementations, some deposition of the film can occur on the barrier layer, which may lead to defects (such as...). Figure 5 (Illustrations are indicated by nodules). In one or more embodiments, the polymer is removed along with the defects, and the polymerization reaction restarts, continuing selective growth.

[0042] One or more embodiments of this disclosure relate to a method for selectively depositing a barrier layer on the metal surface of a substrate having a metal surface and a dielectric surface. The method includes exposing the substrate to an alkyne and a nitrogen reactant to selectively form a barrier layer on the metal surface, the nitrogen reactant including an azide or a nitrile oxide.

[0043] In some embodiments, the metal surface includes copper. In some embodiments, the metal surface is substantially composed of copper.

[0044] In some embodiments, the alkyne and nitrogen reactant are simultaneously exposed to the substrate. In some embodiments, the exposure is performed via exposure of the substrate to a solution phase below a solution comprising both the alkyne and the nitrogen reactant. In some embodiments, the exposure is performed via exposure of the substrate to a gas phase below a gas comprising both the alkyne and the nitrogen reactant.

[0045] In some embodiments, alkynes and nitrogen reactants are sequentially exposed to the substrate. In some embodiments, the alkynes are first exposed to the substrate. In some embodiments, the nitrogen reactants are first exposed to the substrate. In some embodiments, the exposure is performed via exposure of the substrate to a solution phase below a solution containing either the alkynes or the nitrogen reactants. In some embodiments, the exposure is performed via exposure of the substrate to a gas phase below a gas containing either the alkynes or the nitrogen reactants. In some embodiments, one exposure is in the solution phase and the other is in the gas phase. In some embodiments, the substrate is rinsed (gas phase) or washed (solution phase) to remove the previous reactant before being exposed to the next reactant.

[0046] In some embodiments, the alkyne comprises two or more alkyne moietyes. In some embodiments, the alkyne comprises two, three, four, or more alkyne moietyes. In some embodiments, the alkyne comprises at least one compound of the general formula SiR4, wherein each R is independently selected from C1 to C18 alkyl, aryl, or alkynyl groups, provided that at least one R is alkynyl.

[0047] In some embodiments, the alkyne includes one or more of the following compounds:

[0048]

[0049] R is independently selected from C1 to C18 alkyl or aryl groups.

[0050] In some embodiments, the nitrogen reactant comprises an azide. In some embodiments, the nitrogen reactant consists essentially of an azide. As used in this manner, the term "consistently of an azide" means that the reactive component of the nitrogen reactant (e.g., excluding inert components) is greater than or equal to about 95%, 98%, or 99% azide on a molecular basis. In some embodiments, the nitrogen reactant comprises a nitrile oxide. In some embodiments, the nitrogen reactant consists essentially of a nitrile oxide. As used in this manner, the term "consistently of a nitrile oxide" means that the reactive component of the nitrogen reactant (e.g., excluding inert components) is greater than or equal to about 95%, 98%, or 99% a nitrile oxide on a molecular basis. In some embodiments, the nitrogen reactant substantially does not contain nitrile oxides. As used in this manner, the term "substantially does not contain nitrile oxides" means that the nitrogen reactant has less than or equal to about 5%, 2%, or 1% nitrile oxides on a molecular basis.

[0051] In some embodiments, the azide comprises two or more azide moieties. In some embodiments, the azide comprises two, three, four, or more azide moieties. In some embodiments, the azide comprises at least one compound of the general formula SiR4, wherein each R is independently selected from C1 to C18 alkyl, aryl, or azide groups, provided that at least one R is an azide.

[0052] In some embodiments, the azide comprises one or more of the following compounds:

[0053]

[0054] R is independently selected from C1 to C18 alkyl or aryl groups.

[0055] In some embodiments, the substrate is cleaned before being exposed to alkynes or nitrogen reactants. In some embodiments, only the metal surface of the substrate is cleaned before being exposed to alkynes or nitrogen reactants. In some embodiments, the metal surface of the substrate or the substrate itself is cleaned with hydrogen plasma. In some embodiments, the hydrogen plasma is conductive-coupled plasma (CCP). In some embodiments, the hydrogen plasma is inductively coupled plasma (ICP). In some embodiments, the hydrogen plasma includes H2 plasma.

[0056] In some embodiments, after the barrier layer is deposited, a dielectric layer is selectively deposited on the dielectric surface. In some embodiments, the dielectric layer comprises silicon nitride. The deposition of silicon nitride can be performed via any suitable process. Suitable processes may include exposing the substrate to silicon halides and ammonia. Suitable silicon halides include, but are not limited to: dichlorosilane (DCS), trichlorosilane (TCS), tetrachlorosilane (SiCl4), tetrabromosilane (SiBr4), tetraiodosilane (SiI4), and hexachlorosilane (HCDS).

[0057] In some embodiments, a barrier layer is removed from the substrate. This barrier layer can be removed using any suitable selective etching process. Suitable selective etching processes include, but are not limited to, the use of oxygen plasma and fluorine plasma. In some embodiments, when the barrier layer is removed using oxygen plasma, a metal oxide layer is formed on the metal surface. In some embodiments, the metal oxide formed on the metal surface is removed by using a reduction process. Suitable reduction processes include, but are not limited to, the use of plasma comprising hydrogen or ammonia and thermal annealing comprising hydrogen or ammonia. In some embodiments, the oxygen plasma, fluorine plasma, hydrogen plasma, and ammonia plasma can be generated independently, remotely or internally, and these plasmas can be conductively coupled or inductively coupled.

[0058] In some embodiments, after the silicon nitride layer is deposited, the barrier layer is removed by sequentially exposing the substrate to oxygen plasma and then to hydrogen plasma. The substrate is exposed to alkyne and nitrogen reactants to selectively block metal surfaces and selectively deposit a silicon nitride film on dielectric surfaces. The removal of the barrier layer, exposure of the substrate, and deposition of the silicon nitride film can be repeated until a silicon nitride film of a predetermined thickness is formed.

[0059] In some embodiments, the cobalt surface may have enhanced surface reactivity or be made inert. In some embodiments, cobalt may participate in catalysis in the presence of an epoxide to form a new functionalized surface. This newly formed surface can be used for further processing.

[0060] One or more embodiments of this disclosure relate to a method of selectively depositing a barrier layer on a metal surface of a substrate having a metal surface and a dielectric surface. The method includes exposing the substrate to an epoxide to selectively form a barrier layer on the metal surface. In some embodiments, the metal surface comprises cobalt. In some embodiments, the metal surface is substantially composed of cobalt.

[0061] In some embodiments, the exposure is performed via solution phase exposure of the substrate to a solution comprising an epoxide. In some embodiments, the exposure is performed via gas phase exposure of the substrate to a gas comprising an epoxide.

[0062] In some embodiments, the epoxide comprises two or more epoxide moieties. In some embodiments, the epoxide is substituted. In some embodiments, the epoxide comprises two, three, four, or more epoxide moieties. In some embodiments, the epoxide comprises one or more of the following compounds:

[0063]

[0064] R is independently selected from C1 to C4 alkyl groups.

[0065] In some embodiments, the epoxide comprises two or more epoxide portions, each of which reacts with the substrate surface. In some embodiments, the epoxide comprises two or more epoxide portions, wherein only one epoxide portion reacts with the substrate surface.

[0066] In some embodiments, the substrate is cleaned before being exposed to the epoxide. In some embodiments, only the metal surface of the substrate is cleaned before being exposed to the epoxide. In some embodiments, the metal surface of the substrate or the substrate itself is cleaned with hydrogen plasma. In some embodiments, the hydrogen plasma is conductive-coupled plasma (CCP). In some embodiments, the hydrogen plasma is inductively coupled plasma (ICP). In some embodiments, the hydrogen plasma includes H2 plasma.

[0067] In some embodiments, after the barrier layer is deposited, a dielectric layer is selectively deposited on the dielectric surface. In some embodiments, the dielectric layer comprises silicon nitride. The deposition of silicon nitride can be performed via any suitable process. Suitable processes may include exposing the substrate to silicon halides and ammonia. Suitable silicon halides include, but are not limited to: dichlorosilane (DCS), trichlorosilane (TCS), tetrachlorosilane (SiCl4), tetrabromosilane (SiBr4), tetraiodosilane (SiI4), and hexachlorosilane (HCDS).

[0068] In some embodiments, a barrier layer is removed from the substrate. This barrier layer can be removed using any suitable selective etching process. Suitable selective etching processes include, but are not limited to, the use of oxygen plasma and fluorine plasma. In some embodiments, when the barrier layer is removed using oxygen plasma, a metal oxide layer is formed on the metal surface. In some embodiments, the metal oxide layer formed on the metal surface is removed by using a reduction process. Suitable reduction processes include, but are not limited to, the use of plasma comprising hydrogen or ammonia and thermal annealing comprising hydrogen or ammonia. In some embodiments, the oxygen plasma, fluorine plasma, hydrogen plasma, and ammonia plasma can be generated independently, remotely or internally, and these plasmas can be conductively coupled or inductively coupled.

[0069] Silyl halide precursors typically do not chemically adsorb onto SiO2 surfaces because the surface Si-OH groups do not react with Si-Cl under gas-phase ALD conditions. For example, ALD SiO2 films are not formed by the SiCl4 / H2O process under typical ALD conditions. However, the inventors have discovered that adding a titanium precursor to the ALD scheme (SiCl4 / H2O / TiCl4 / H2O) can cause Ti... x Si y O z Membrane formation.

[0070] Unrestricted by theory, it is believed that although Si-OH does not react with Si-Cl, Ti-OH reacts with Si-Cl due to Ti's lower electronegativity than Si, and Ti-OH is more reactive to Si-Cl than Si-OH. In some embodiments, this difference in reactivity is used to block TiN but not SiO2.

[0071] TiN surfaces oxidize upon exposure to air and acquire Ti-OH groups. When RSiCl3 (SAM) is pulsed through air onto exposed TiN and SiO2 surfaces, the Si-Cl bonds react with the Ti-OH groups on the surface, rather than with the Si-OH groups themselves.

[0072] Some embodiments of this disclosure relate to methods for blocking TiN, W, Cu, or Co in the gas and / or solution phases with trichlorosilane-based hydrocarbons. In some embodiments, several compounds of the general formula SiX3R are used to block the TiN, W, Cu, or Co surfaces, where X is a halogen and R is a C1 to C18 alkyl, aryl, or alkylamine.

[0073] One or more embodiments of this disclosure relate to a method of selectively depositing a barrier layer on the metal surface of a substrate having a metal surface and a dielectric surface. The method includes exposing the substrate to a trihalosilicon-based hydrocarbon to selectively form a barrier layer on the metal surface, the trihalosilicon-based hydrocarbon comprising at least one compound of the general formula SiX3R, wherein R is a C1 to C18 alkyl, aryl, or alkylamine group.

[0074] In some embodiments, exposure to the trihalosilicon-based hydrocarbons is performed via solution phase exposure of the substrate to a solution containing the trihalosilicon-based hydrocarbons. In some embodiments, exposure to the trihalosilicon-based hydrocarbons is performed via gas phase exposure of the substrate to a gas containing the trihalosilicon-based hydrocarbons.

[0075] In some embodiments, the trihalosilicon-based hydrocarbon includes one or more of the following compounds:

[0076]

[0077] R = Cl, Br, I

[0078] R1 = tBu, Me, Et, iPr, hydrocarbons from C3 to C18, NMe2, Net2, phenyl, benzyl

[0079] In some embodiments, R1 is any C1-C18 alkyl, aryl, alkylamine, or benzyl.

[0080] In some embodiments, the trihalosilicon-based hydrocarbon comprises at least one compound of the general formula SiX3R, wherein R is a C1 to C18 alkyl, aryl, or alkylamine group. As used in this regard, "alkylamine" refers to an amino group with an alkyl substituent. In other words, the alkylamine substituent has the general formula -NR2, wherein each R is independently H, a C1 to C6 alkyl, or an aryl group. For example, -N(CH3)2 and -N(CH2CH3)2.

[0081] In some embodiments, the substrate is first exposed to air before being exposed to trihalosilicon-based hydrocarbons. In some embodiments, only the metal surface of the substrate is exposed to air before being exposed to trihalosilicon-based hydrocarbons.

[0082] Example

[0083] ODTS (octadecyltrichlorosilane) blocks the TiN surface

[0084] ODTS was dissolved in toluene, and the sample was immersed in the solution at room temperature for a predetermined time. After immersion, the sample was washed with toluene and dried with nitrogen. SAM formation was monitored by measuring the water contact angle (WCA). During a 1-second immersion, SAM formation saturated on TiN but not on SiO2. As the immersion time increased, the WCA on TiN remained constant, but the WCA on SiO2 increased.

[0085] Low-temperature ALD SiON deposition was performed on a SAM-treated substrate to evaluate selective dielectric deposition. The substrate was maintained at 200°C, and alternating pulses of hexachlorosilane (HCDSO) and NH3 were applied. The SiON film thickness was measured using an ellipsometry. Approximately 5-fold selectivity was observed after 150 cycles. Selectivity decreased with increasing cycle number.

[0086] The TiN surface is blocked by OTS (octylpropylsilane).

[0087] OTS was dissolved in toluene, and the sample was immersed in the solution at room temperature for a predetermined time. After immersion, the sample was washed with toluene and dried with nitrogen. SAM formation was monitored by measuring the water contact angle (WCA). Changes in WCA showed a similar trend to those observed in the ODTS experiment.

[0088] The thermal stability of SAM deposited on various substrates was evaluated using WCA measurements. OTS SAM was deposited in both solution and vapor phases. Samples with deposited SAM were annealed at temperatures ranging from 200°C to 350°C for 1 hour, and WCA was measured before and after annealing. SAM on TiN and W was found to be stable up to 250°C, but deteriorated above this temperature. Conversely, SAM on SiO2 was stable up to 350°C. Compared to solution phase, vapor phase SAM deposition provides more flexibility to achieve higher WCA variations between TiN and SiO2.

[0089] The chemical stability of SAM was assessed by annealing samples deposited with SAM in the precursors (HCDSO and NH3) used in SiON deposition at 200 °C for one hour. Although SAM was stable in the ALD precursor at 200 °C, some degradation still occurred.

[0090] One or more embodiments of this method use an atomic layer deposition (ALD) process to provide a barrier layer. In a time-domain ALD process, exposure to each reactive compound is separated by a time delay to allow each compound to adhere to and / or react on the substrate surface, after which these compounds are rinsed from the processing chamber. Mixing of these reactive gases is prevented by rinsing them out of the processing chamber between subsequent exposures.

[0091] In the spatial ALD process, reactive gases flow into different processing zones within a processing chamber. These different processing zones are separated from adjacent processing zones so that the reactive gases do not mix. The substrate can be moved between these processing zones to expose the substrate to the processing gases individually. During substrate movement, different portions of the substrate surface, or material on the substrate surface, are exposed to two or more reactive compounds, such that no given point on the substrate is substantially exposed to more than one reactive compound simultaneously. As will be understood by those skilled in the art, it is possible for a small portion of the substrate to be simultaneously exposed to multiple reactive gases due to gas diffusion within the processing chamber, and unless otherwise specified, such simultaneous exposure is not intentional.

[0092] In one aspect of the time-domain ALD process, a first reactive gas (i.e., a first precursor or compound A) is pulsed into the reaction zone, followed by a first time delay. Then, a second precursor or compound B is pulsed into the reaction zone, followed by a second delay. During each time delay, a purge gas, such as argon, is introduced into the processing chamber to purge the reaction zone or otherwise remove any residual reactive compounds, reaction products, or byproducts from the reaction zone. Alternatively, the purge gas may flow continuously throughout the deposition process, such that only the purge gas flows during the time delay between pulses of the reactive compounds. The reactive compounds are pulsed alternately until a predetermined film or film thickness is formed on the substrate surface. In either case, the ALD process of pulsed delivery of compound A, purge gas, compound B, and purge gas constitutes one cycle. The cycle may begin with either compound A or compound B and continue in the corresponding sequence until a film of the predetermined thickness is achieved.

[0093] In a spatial ALD process implementation, a first reactive gas and a second reactive gas are simultaneously delivered to the reaction zone, but separated by an inert gas curtain and / or a vacuum curtain. This gas curtain can be a combination of an inert gas flow entering the processing chamber and a vacuum flow exiting the processing chamber. The substrate moves relative to the gas delivery device such that any given point on the substrate is exposed to both the first and second reactive gases.

[0094] As used herein, “pulse” or “reagent” refers to the amount of source gas introduced into the processing chamber intermittently or discontinuously. The amount of a particular compound within each pulse may vary over time, depending on the pulse duration. A particular processing gas may include a single compound, or a mixture / combination of two or more compounds.

[0095] The duration of each pulse / dosing is variable and can be adjusted to suit, for example, the volumetric capacity of the processing chamber and the capacity of the vacuum system coupled to the processing chamber. Furthermore, the dosing time of the processing gas can vary depending on factors such as the flow rate of the processing gas, the temperature of the processing gas, the type of control valve, the type of processing chamber used, and the ability of the components of the processing gas to adsorb onto the substrate surface. The dosing time can also vary depending on the type of layer formed and the geometry of the device formed. The dosing time should be long enough to provide sufficient volume of compound for adsorption / chemisorption onto substantially the entire surface of the substrate and the formation of a layer of processing gas components thereon.

[0096] While the above-described implementation of the processing method involves only two pulses of reactive gas, it will be understood that this is merely exemplary and additional pulses of processing gas may be used. These pulses may be repeated in whole or in part. The cycle may be repeated to form a barrier layer of a predetermined thickness. In some embodiments, the cycle is repeated to form a barrier layer of the following thickness: in approximately to approximately Within the scope, or in the approximate to approximately Within the scope, or in the approximate to approximately Within the range.

[0097] Once the predetermined thickness has been reached, the method may include further processing (e.g., bulk deposition of a dielectric film). In some embodiments, this further processing may be an ALD process. For example, in some embodiments, an ALD process may be performed to deposit the silicon nitride bulk to the target thickness.

[0098] Although this disclosure has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of this disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the methods and apparatus of this disclosure without departing from the spirit and scope of this disclosure. Therefore, it is intended that this disclosure include modifications and variations within the scope of the appended claims, as well as their equivalents.

Claims

1. A method for selectively depositing a barrier layer, the method comprising: A barrier layer is selectively formed on a metal surface of a substrate using a silane, the substrate having the metal surface and a dielectric surface, the silane comprising at least one compound of the general formula SiH3R, wherein R is an alkyl, perfluorinated alkyl, alkenyl, or alkynyl group selected from C4 to C20; and After forming the barrier layer, a silicon nitride layer is selectively deposited on the dielectric surface. The metal surface mentioned includes copper, cobalt, tungsten, tantalum, tantalum nitride, tantalum oxide, titanium, titanium nitride, titanium oxide, ruthenium, ruthenium oxide, or iridium, and The silicon nitride layer is blocked from deposition on the metal surface via the barrier layer.

2. The method of claim 1, wherein the silane comprises dodecylsilane (C 12 H 25 SiH3).

3. The method of claim 1, wherein the barrier layer substantially does not include crosslinking.

4. The method of claim 1, further comprising: The metal surface is cleaned with hydrogen plasma before the substrate is exposed to the silane.

5. The method of claim 1, further comprising: After depositing the silicon nitride layer, repeat the following steps until the silicon nitride layer has reached a predetermined thickness: expose the substrate to silane and deposit the silicon nitride layer.

6. The method of claim 5, wherein the predetermined thickness is in the range of 10 Å to 50 Å.

7. The method of claim 5, wherein the predetermined thickness is greater than or equal to 50 Å.

8. A method for selectively depositing a barrier layer, the method comprising: A barrier layer is selectively formed on a metal surface of a substrate, comprising the metal surface and a dielectric surface, by exposing the substrate to alkynes and nitrogen reactants, wherein the nitrogen reactants include azides or nitrile oxides; and After forming the barrier layer, a silicon nitride layer is selectively deposited on the dielectric surface. The metal surface mentioned therein includes copper, cobalt, tungsten, tantalum, tantalum nitride, tantalum oxide, titanium, titanium nitride, titanium oxide, ruthenium, ruthenium oxide, or iridium.

9. The method of claim 8, wherein the metal surface comprises copper.

10. The method of claim 8, further comprising: The metal surface is cleaned with hydrogen plasma before the substrate is exposed to the alkyne or nitrogen reactant.

11. The method of claim 8, wherein the alkyne comprises two or more alkyne moieties.

12. The method of claim 8, wherein the alkyne comprises at least one compound of the general formula SiR4, wherein each R is independently selected from C1 to C18 alkyl, aryl, or alkynyl groups, provided that at least one R is alkynyl.

13. The method of claim 8, wherein the azide comprises two or more azide portions.

14. The method of claim 8, wherein the azide comprises at least one compound of the general formula SiR4, wherein each R is independently selected from C1 to C18 alkyl, aryl, or azide groups, provided that at least one R is an azide.

15. The method of claim 8, wherein the nitrogen reactant substantially does not include nitrile oxides.

16. The method of claim 8, wherein the alkyne comprises one or more of the following: , , , , , , , or , Each of the R groups is independently selected from C1 to C18 alkyl or aryl groups.

17. The method of claim 8, wherein the azide comprises one or more of the following: , , , , , or , Each of the R groups is independently selected from C1 to C18 alkyl or aryl groups.

18. A method for selectively depositing a barrier layer, the method comprising: The barrier layer is selectively formed by exposing a substrate having a metal surface and a dielectric surface to an epoxide to form a barrier layer on the metal surface; and After forming the barrier layer, a silicon nitride layer is selectively deposited on the dielectric surface. The metal surface mentioned therein includes copper, cobalt, tungsten, tantalum, tantalum nitride, tantalum oxide, titanium, titanium nitride, titanium oxide, ruthenium, ruthenium oxide, or iridium.

19. The method of claim 18, wherein the metal surface comprises cobalt.

20. The method of claim 18, wherein the epoxide is substituted.

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