Selective deposition of metal oxides on metal surfaces

Abstract

Methods are provided for selective deposition of metal oxide films on a metal or metallic surface relative to an oxide surface. The oxide surface of a substrate can be selectively passivated relative to the metal or metallic surface, for example, by exposing the substrate to a silanizing agent. A metal oxide is selectively deposited from a gas phase reactant on the metal or metallic surface relative to the passivated oxide surface.

Description

[0001] Citation of relevant applications

[0002] This application claims priority to U.S. Provisional Application No. 62 / 833,256, filed April 12, 2019, which is incorporated herein by reference. background Technical Field

[0004] This disclosure generally relates to the selective deposition of metal oxides on a first metallic or metallic surface of a substrate relative to a second dielectric surface of the substrate. Background Technology

[0006] The ever-shrinking device dimensions in semiconductor manufacturing demand new and innovative processing methods. Conventionally, patterning in semiconductor processing involves subtractive processes, where a blanket coating is deposited, masked using photolithography, and etched through openings in the mask. Additive patterning is also known, where the masking step precedes the deposition of the material of interest, such as patterning using lift-off techniques or damascene processing. In most cases, expensive multi-step photolithography techniques are used for patterning.

[0007] Patterning can be simplified through selective deposition, which has attracted increasing interest from semiconductor manufacturers. Selective deposition is highly beneficial in a variety of ways. Importantly, it reduces the number of lithography steps, thereby lowering processing costs. Selective deposition also enables enhanced miniaturization in narrow structures. Attached Figure Description

[0008] Figure 1A A schematic cross-section of a portion of a substrate having a first metal surface and a second adjacent oxide surface according to a first embodiment.

[0009] Figure 1B After selective passivation of oxide surfaces Figure 1A A schematic cross-section of the substrate.

[0010] Figure 1C After selective deposition of metal oxides on metal surfaces Figure 1B A schematic cross-section of the substrate.

[0011] Figure 1D After removing passivation material from oxide surface Figure 1C A schematic cross-section of the substrate. Summary of the Invention

[0012] In some aspects, methods are provided for selectively depositing a metal oxide on a metal surface of a substrate relative to a dielectric surface, such as an oxide surface. In some embodiments, a dielectric surface is selectively passivated relative to a metal surface and a metal oxide is selectively deposited from a gas phase reactant on the metal surface relative to the passivated dielectric surface. In some embodiments, the metal surface comprises Al, Cu, Co, Ni, W, Nb, Fe, or Mo. In some embodiments, the dielectric surface comprises a dielectric transition metal oxide. In some embodiments, the dielectric surface comprises aluminum oxide, zirconium oxide, hafnium oxide, titanium oxide, tantalum oxide, yttrium oxide, or lanthanum oxide.

[0013] In some embodiments, selectively passivating a dielectric surface, such as an oxide surface, comprises exposing the dielectric surface to a silylating agent. In some embodiments, the silylating agent is an alkylaminosilane. In some embodiments, the silylating agent is a silane. In some embodiments, the silylating agent comprises allyltrimethylsilane (TMS-A), trimethylchlorosilane (TMS-Cl), N-(trimethylsilyl)imidazole (TMS-Im), octadecyltrichlorosilane (ODTCS), hexamethyldisilazane (HMDS), or N-(trimethylsilyl)dimethylamine (TMSDMA).

[0014] In some embodiments, the dielectric surface comprises aluminum oxide. Aluminum oxide can be deposited using an aluminum precursor, including trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), dimethylaluminum isopropoxide (DMAI), tri(tert-butyl)aluminum (TTBA), tri(isopropylalcohol)aluminum (TIPA), or triethylaluminum (TEA). In some embodiments, aluminum oxide is deposited using a heteroleptic aluminum compound comprising an alkyl group and a different ligand, such as a halide. In some embodiments, aluminum oxide is deposited by ALD using an aluminum precursor and water.

[0015] In some embodiments, a passivation blocking layer is formed on the metal surface prior to selectively passivating the dielectric surface. Such a passivation blocking layer can comprise, for example, a self-assembled monolayer (SAM). DETAILED DESCRIPTION

[0016] A metal oxide can be selectively deposited over a first metal (or metallic) surface relative to a second dielectric surface, such as an oxide surface. In some embodiments, the oxide surface is adjacent to the metal surface. In embodiments described herein, the oxide surface can be selectively passivated relative to the metal surface, for example by silanization. Subsequently, a metal oxide layer is selectively deposited on the metal surface relative to the passivated oxide surface. The metal oxide layer can be deposited by a vapor deposition process, such as an atomic layer deposition process. In some embodiments, the oxide surface on the substrate is silanized with a silanization agent, such as allyltrimethylsilane (TMS-A), trimethylchlorosilane (TMS-Cl), N-(trimethylsilyl)imidazole (TMS-Im), octadecyltrichlorosilane (ODTCS), hexamethyldisilazane (HMDS), or N-(trimethylsilyl)dimethylamine (TMSDMA), and subsequently a metal oxide is selectively deposited on the metal surface of the substrate relative to the passivated oxide surface. In some embodiments, the metal oxide layer can be an aluminum oxide layer, such as an Al2O3 layer. For example, an aluminum oxide layer can be selectively deposited by an ALD process, for example using an aluminum reactant such as trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), dimethylaluminum isopropoxide (DMAI), tri(tert-butyl)aluminum (TTBA), tri(isopropylalcohol)aluminum (TIPA), or triethylaluminum (TEA) and water as reactants.

[0017] In some embodiments, a metal or metallic surface of a substrate includes an elemental metal or metal alloy, while a second, different surface of the substrate includes a dielectric material, such as an oxide. Examples include silicon oxide-based materials, including grown or deposited silicon dioxide, doped and / or porous oxides, native oxides on silicon, and the like. The surface of the dielectric layer is selectively passivated relative to the metal or metallic surface, such as by selective silanization. Subsequently, a metal oxide layer is selectively deposited on the metal or metallic surface relative to the passivated dielectric surface. Examples of metal oxides that can be deposited include dielectrics, such as zirconium oxide (e.g., ZrO2), hafnium oxide (e.g., HfO2), aluminum oxide (e.g., Al2O3), titanium nitride (e.g., TiN), and titanium oxide (e.g., TiO2). In some embodiments, the metal or metallic surface on which the metal oxide is selectively deposited is at least partially adjacent to the dielectric surface that is selectively passivated. For example, at least a portion of the metal or metallic surface can be adjacent to the oxide surface.

[0018] In some embodiments, a passivation blocking layer, such as a self-assembled monolayer (SAM), can be provided to the metal or metallic surface prior to forming a passivation layer on a dielectric surface, such as an oxide surface. The passivation blocking layer can facilitate the selectivity of the dielectric surface to silanization, and can be subsequently removed to allow selective deposition of a metal oxide on the metal or metallic surface relative to the silanized dielectric surface.

[0019] The passivation layer (silanization) can be removed from a dielectric surface, such as from an oxide surface, after the selective deposition of a metal oxide layer over a metal or metallic surface. Conditions can be selected to avoid damaging surrounding materials on the substrate.

[0020] Examples of suitable reactors that can be used in the selective deposition processes described herein include commercially available ALD equipment. In addition to ALD reactors, many other kinds of reactors capable of growing organic passivation layers can also be employed, including CVD reactors, VDP reactors, and MLD reactors.

[0021] Substrate surface

[0022] According to some aspects of the disclosure, selective deposition can be used to preferentially deposit a film of interest, such as a metal oxide film, on a metal or metallic surface relative to an oxide surface or other dielectric surface. In some embodiments, the two surfaces on the substrate are at least partially adjacent to one another. Selective passivation, such as selective silanization, of the oxide surface relative to the metal or metallic surface will facilitate subsequent selective deposition of a layer of interest, such as a metal oxide layer, on the metal or metallic surface relative to the silanized oxide surface.

[0023] For example, one of the surfaces can be a conductive metal or metallic surface of a substrate, and the other surface can be a non-conductive oxide surface of the substrate. In some embodiments, the non-conductive surface comprises -OH groups, such as a silicon oxide-based surface (e.g., low-k materials, including grown and deposited silicon oxide materials and native oxides on silicon). The oxide surface can be selectively passivated relative to the metal or metallic surface by exposure to a silanization agent, and a metal oxide can then be selectively deposited on the metal or metallic surface relative to the silanized oxide surface.

[0024] The difference in material between the two substrate surfaces enables the vapor deposition process to selectively passivate the oxide surface relative to the metal or metallic surface. In some embodiments, a cyclic vapor deposition process, such as a cyclic CVD or atomic layer deposition (ALD) process, is used. In some embodiments, the selectivity to the passivation layer can be achieved without a passivation / blocking agent on the metal or metallic surface (to receive less passivation layer) and / or without a catalyst on the surface of the oxide layer to receive more passivation layer. For example, in embodiments where the first surface is metallic and the second surface is an oxide, the oxide layer can be selectively silanized relative to the metal or metallic surface without pre-treatment of the oxide surface or the metal or metallic surface. In other embodiments, the metal or metallic surface is first treated to inhibit passivation (e.g., silanization) of the surface. For example, a passivation blocking self-assembled monolayer (SAM) can first be formed over the metal or metallic surface relative to the oxide surface, thereby facilitating selective deposition of the passivation layer on the oxide surface over the SAM covering the metallic surface. The passivation inhibitor can be removed after the selective passivation and prior to deposition of the metal oxide. After the selective deposition of the passivation layer is complete, selective deposition of a material of interest, such as a metal oxide, can be performed on the non-passivated metal or metallic surface relative to the passivated surface.

[0025] As used herein, unless otherwise indicated, if a surface is referred to herein as a metal surface, it can be a metallic or metal surface. In some embodiments, the metallic or metal surface can include surface oxidation. In some embodiments, the material of the metal surface is electrically conductive with or without surface oxidation. In some embodiments, the metal surface includes one or more transition metals. In some embodiments, the metal surface includes one or more of Al, Cu, Co, Ni, W, Nb, Fe, or Mo. In some embodiments, the metal surface includes Cu. In some embodiments, the metal surface is a copper surface. In some embodiments, the metallic surface includes titanium nitride. In some embodiments, the metal surface includes one or more noble metals, such as Ru. In some embodiments, the metal surface includes a metal oxide, such as an electrically conductive metal oxide, a metal nitride, a carbide, a boride, or a combination thereof. For example, the metallic or metal surface can include one or more of RuO x , NbC x , NbB x , NiO x , CoO x , NbO x , MoO x , WO x , WNC x , TaN, or TiN.

[0026] In some embodiments, the metal or metallic surface is a surface that can accept or coordinate with a precursor employed in a selective deposition process of a layer of interest, such as a metal oxide, as described herein.

[0027] As mentioned above, in some embodiments, the metal or metallic surface can include a passivation blocking layer thereover. That is, in some embodiments, the metal or metallic surface can include a material that will inhibit the formation of a passivation layer, such as a self-assembled monolayer (SAM), on the metal or metallic surface. In some embodiments, the deposition process includes forming a passivation blocking layer on the metal or metallic surface but not on the surface to be passivated.

[0028] Passivation of substrate surface

[0029] In some embodiments, an oxide (or other dielectric) surface can be passivated. In some embodiments, the passivation is selective to the oxide surface relative to another surface, such as a metal or metallic surface on the same substrate. In some embodiments, the oxide surface is silylated by one or more exposures to a gas phase silylating agent. For example, in a passivation step, a silylating agent can be conducted in a reaction space and contacted with the oxide surface. The silylating agent can be, for example, a chlorosilane, an alkoxysilane, a silyl halide, a silyl cyanate, a silyl azide, a silyl isocyanate, a silyl isothiocyanate, a silyl sulfonate, a silyl acetamide, a silyl carbodiimide, an allyl silane, or a nitrogen-containing silane such as a silazane, an imidazole, or an amine. In some embodiments, the silylating agent is allyltrimethylsilane (TMS-A), trimethylchlorosilane (TMS-Cl), N-(trimethylsilyl)imidazole (TMS-Im), octadecyltrichlorosilane (ODTCS), hexamethyldisilazane (HMDS), or N-(trimethylsilyl)dimethylamine (TMSDMA) and the silylation includes exposing the substrate to one or more pulses of the silylating agent. In some embodiments, both the metal or metallic surface and the oxide surface are contacted with a silylating agent such as allyltrimethylsilane (TMS-A), trimethylchlorosilane (TMS-Cl), N-(trimethylsilyl)imidazole (TMS-Im), octadecyltrichlorosilane (ODTCS), hexamethyldisilazane (HMDS), or N-(trimethylsilyl)dimethylamine (TMSDMA). In some embodiments, the oxide surface of the substrate is selectively silylated relative to the metal or metallic surface of the substrate.

[0030] In some embodiments, the silylating agent is an alkylaminosilane. For example, the oxide surface of the substrate can be contacted with an alkylaminosilane having the formula (R I )3Si(NR II R III ), where RI is a linear or branched C1-C5 alkyl group or a linear or branched C1-C4 alkyl group, R II is a linear or branched C1-C5 alkyl group, a linear or branched C1-C4 alkyl group, or hydrogen, R III is a linear or branched C1-C5 alkyl group or a linear or branched C1-C4 alkyl group.

[0031] In some embodiments, the silylating agent is a silane. For example, the oxide surface can be contacted with a silane having the general formula (R I )3SiA, where R I is a linear or branched C1-C5 alkyl group or a linear or branched C1-C4 alkyl group, and A is any ligand that can react with a silicon-containing surface.

[0032] The silylating agent can be provided to the reaction chamber containing the substrate in a single pulse or in a series of multiple pulses. In some embodiments, the silylating agent is provided in a single long pulse or in a plurality of shorter pulses. The pulses can be provided sequentially. In some embodiments, the silylating agent is provided in 1 to 25 pulses for a duration of about 0.1 to about 60 seconds. Between pulses, the silylating agent can be removed from the reaction space. For example, the reaction chamber can be evacuated and / or purged with an inert gas. The purging can last, for example, about 1 to 30 seconds or more.

[0033] In some embodiments, the temperature of the silylation process can be, for example, about 50 to 500 °C, or about 100 to about 300 °C. The pressure during the silylation process can be, for example, about 10 -5 to about 760 Torr, or in some embodiments about 1 to 10 Torr or about 0.1 to about 10 Torr.

[0034] In some embodiments, the silylation process can be performed in situ, i.e., in the same reaction chamber as a subsequent deposition process, for example, selective deposition of a metal oxide such as aluminum oxide on a non-silylated surface relative to the silylated surface. However, in some embodiments, the silylation can be performed in a separate reaction chamber. In some embodiments, the reaction chamber in which the silylation is performed is part of a cluster tool that includes one or more additional reaction chambers. For example, such a cluster tool can include additional reaction chambers for deposition of a metal oxide and / or for etching one or more layers. In some embodiments, the cluster tool includes separate modules for pretreatment, silylation of the oxide surface, selective deposition of a metal oxide, and subsequent post-deposition processing such as etching or post-deposition plasma cleaning. In some embodiments, the same module can be used for two or more processes.

[0035] In some embodiments, the substrate can be pre-treated or cleaned prior to or at the beginning of the passivation and / or selective deposition process. In some embodiments, the substrate can be subjected to a plasma cleaning process prior to or at the beginning of the selective passivation and / or selective deposition process. In some embodiments, the plasma cleaning process can not include ion bombardment, or can include a relatively small amount of ion bombardment. In some embodiments, the substrate surface can be exposed to a plasma, radical, excited species, and / or atomic species prior to or at the beginning of the passivation process and / or selective metal oxide deposition process. In some embodiments, the substrate surface can be exposed to a hydrogen plasma, radical, or atomic species prior to or at the beginning of the selective passivation process and / or selective metal oxide deposition process.

[0036] Selective deposition of metal oxides on metal or metallic surfaces relative to passivated oxide surfaces

[0037] The metal oxide can be selectively deposited on a metallic or metal-like surface of the substrate relative to a passivated oxide surface of the substrate. After selectively forming a passivation layer on the oxide surface, in some embodiments, the metal oxide is selectively deposited on the second surface by alternating and sequential contacting of the substrate with a first reactant comprising a metal of the metal oxide and a second reactant comprising oxygen. In some embodiments, the second reactant is water. In some embodiments, the substrate is sequentially contacted with the first and second reactants such that the metal oxide is selectively deposited on or over the metallic or metal-like surface (see, e.g., Figures 1A-1D ).

[0038] In some embodiments, the metal reactant is a hydrophobic reactant comprising one or more hydrophobic ligands. In some embodiments, the hydrophobic reactant comprises two to four hydrophobic ligands. In the case of a hydrophobic reactant comprising a metal having a valence / oxidation state of n, in some embodiments, the hydrophobic precursor comprises n-1 or n-2 hydrophobic ligands.

[0039] In some embodiments, at least one hydrophobic ligand comprises only C and H. In some embodiments, at least one hydrophobic ligand comprises C, H, and Si or Ge, but no additional elements.

[0040] In some embodiments, the hydrocarbon ligand comprises one or more of the following:

[0041] • C1-C10 hydrocarbon (single, double, or triple bond)

[0042] o alkyl

[0043] • C1-C5 alkyl

[0044] • Me, Et, Pr, i Pr, Bu, t Bu

[0045] o alkenyl

[0046] ■C1-C6 alkenyl,

[0047] o cyclic hydrocarbon

[0048] ●C3-C8

[0049] ●cyclopentadienyl

[0050] ●cycloheptadienyl

[0051] ●cycloheptatrienyl

[0052] ●cyclohexyl

[0053] ●derivatives thereof

[0054] o aromatic

[0055] ■C6 aromatic rings and derivatives thereof

[0056] In some embodiments, the hydrophobic metal reactant does not comprise a hydrophilic ligand. However, in some embodiments, the hydrophobic metal reactant can comprise one or two hydrophilic ligands. In some embodiments, the hydrophilic ligand comprises a nitrogen, oxygen, and / or halogen group.

[0057] In some embodiments, the hydrophilic ligand is an alkyl amine (-NR2, where each R can be an alkyl group, hydrogen). In some embodiments, the hydrophilic ligand can be -NMe2, -NEtMe, or -NEt2.

[0058] In some embodiments, the hydrophilic ligand is an alkoxide, such as -OMe, -OEt, -O i Pr, -O t Bu.

[0059] In some embodiments, the hydrophilic ligand comprises a halide, such as a chloride, fluoride, or other halide.

[0060] In some embodiments, the hydrophobic precursor comprises the formula:

[0061] o L n MX y wherein

[0062] ■in some embodiments, n is 1-6;

[0063] ●in some embodiments, n is 1-4 or 3-4.

[0064] ■in some embodiments, y is 0-2;

[0065] ●in some embodiments, y is 0-1.

[0066] ■L is a hydrophobic ligand;

[0067] • In some embodiments, L is Cp or a C1-C4 alkyl ligand.

[0068] ■X is a hydrophilic ligand;

[0069] • In some embodiments, X is an alkyl amine, alkoxide, or halide ligand.

[0070] ■M is a metal (including Group 13 elements, B, and Ga);

[0071] • In some embodiments, M has an oxidation state from +I up to +VI.

[0072] • In some embodiments, M has an oxidation state of +IV to +V.

[0073] • In some embodiments, M can be a transition metal.

[0074] • In some embodiments, M is Ti, Ta, Nb, W, Mo, Hf, Zr, V, or Cr.

[0075] • In some embodiments, M is Hf, Zr, Ta, or Nb.

[0076] • In some embodiments, M is Zr.

[0077] • In some embodiments, M is Co, Fe, Ni, Cu, or Zn.

[0078] • In some embodiments, the metal is not W or Mo.

[0079] • In some embodiments, M can be a rare earth metal.

[0080] • In some embodiments, M is La, Ce, or Y.

[0081] • In some embodiments, M can be a metal from Groups 2-13.

[0082] • In some embodiments, M is Ba, Sr, Mg, Ca, or Sc.

[0083] • In some embodiments, M is not a noble metal.

[0084] More generally, in some embodiments, the selective ALD process employs a metal precursor. In some embodiments, the metal of the metal precursor can be selected from Al, Ti, Ta, Nb, W, Mo, Hf, Zr, V, Cr, Co, Fe, Ni, Cu, Zn, La, Ce, Y, Ba, Sr, Mg, Ca, or Sc, or mixtures thereof. In some embodiments, the metal can be Al.

[0085] In some embodiments, aluminum oxide is selectively deposited and the selective ALD process employs an Al precursor. Examples of Al precursors include trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), dimethylaluminum isopropoxide (DMAI), tri(tert-butyl)aluminum (TTBA), tri(isopropylal)aluminum (TIPA), or triethylaluminum (TEA). In some embodiments, the aluminum precursor is a heteroleptic aluminum compound. In some embodiments, the heteroleptic aluminum compound includes an alkyl group and another ligand, such as a halide, e.g., CI. In some embodiments, the aluminum compound is dimethylaluminum chloride. In some embodiments, the aluminum precursor is an alkyl precursor that includes two different alkyl groups as ligands. In some embodiments, the aluminum precursor is a metal organic compound. In some embodiments, the aluminum precursor is an organometallic compound.

[0086] In some embodiments, bis(methylcyclopentadienyl)methoxymethylzirconium (IV) ((CpMe)2-Zr-(OMe)Me) is used to selectively deposit zirconium oxide.

[0087] In some embodiments, bis(methylcyclopentadienyl)methoxymethylhafnium (IV) ((CpMe)2-Hf-(OMe)Me) is used to deposit hafnium oxide.

[0088] In some embodiments, the second reactant contributes one or more elements to the selectively deposited material. For example, the second reactant can be an oxygen precursor used to deposit a metal oxide.

[0089] In some embodiments, the second reactant includes an oxygen precursor. In some embodiments, the second reactant includes H2O, O3, H2O2, oxygen plasma, ions, radicals, atomic O, or excited oxygen species.

[0090] In some embodiments, other reactants that will contribute non-O elements to the deposited material can be employed. These reactants can be used in addition to the second oxygen reactant, or these reactants themselves can be used as the second reactant and contribute oxygen and another element to the deposited film. For example, in some embodiments, a nitrogen reactant can be used to contribute nitrogen, a sulfur reactant can be used to contribute sulfur, a carbon reactant can be used to contribute carbon, or a silicon reactant can be used to contribute silicon.

[0091] In some embodiments, a metal oxide film, such as aluminum oxide (e.g., AI2O3), is selectively deposited on one or more metal or metallic surfaces, such as copper, cobalt, titanium nitride, or tungsten surfaces, relative to one or more oxide surfaces. In a first step, the substrate comprising the metal surfaces and the oxide surfaces is treated by a silanization process to form a passivation layer on the oxide surfaces, as described above. For example, in some embodiments, the one or more substrate surfaces can be exposed to a silanization agent, such as allyltrimethylsilane (TMS-A), trimethylchlorosilane (TMS-Cl), N-(trimethylsilyl)imidazole (TMS-Im), octadecyltrichlorosilane (ODTCS), hexamethyldisilazane (HMDS), or N-(trimethylsilyl)dimethylamine (TMSDMA), which selectively silanizes the one or more oxide surfaces. After forming the passivation layer on the oxide surfaces, a metal oxide is selectively deposited on the metal or metallic surfaces relative to the passivated oxide surfaces by a vapor deposition process. The selective deposition can be as described herein. For example, in some embodiments, the aluminum oxide is selectively deposited by alternating and sequential contact of the substrate with an aluminum reactant and an oxygen precursor. The aluminum precursor can include, for example, trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AICI3), dimethylaluminum isopropoxide (DMAI), tri(tert-butyl)aluminum (TTBA), tri(isopropylal)aluminum (TIPA), or triethylaluminum (TEA). The oxygen precursor can include, for example, water. In some embodiments, the aluminum oxide can be deposited by an atomic layer deposition process, in which the substrate is alternately and sequentially contacted with the aluminum reactant and water. In some embodiments, the temperature in the reaction chamber during the aluminum oxide deposition is about 150 to about 350 °C. In some embodiments, the pulse time of the reactants can be about 0.1 to about 10 seconds, and the purge time between reactant pulses can also be about 0.1 to about 10 seconds. In some embodiments, the reaction chamber pressure can be, for example, about 10 -5 to about 760 Torr, or in some embodiments, about 1 to 10 Torr.

[0092] After the selective deposition of the metal oxide, the substrate can be subjected to a post-deposition cleaning step to remove the passivation layer from the oxide surfaces, as described above. In some embodiments, the cleaning step can include an H2plasma treatment. In some embodiments, the cleaning step is performed at a temperature of about room temperature to about 400 °C. In some embodiments, a plasma power of about 25 to 250 W can be used to generate a plasma in flowing H2, for example, at a flow rate of about 10 to 500 seem. In some embodiments, the cleaning time after deposition of the metal oxide layer can be, for example, about 0.1 to 600 seconds or more.

[0093] In some embodiments, a thin metal oxide film such as aluminum oxide (e.g., AI2O3) is selectively deposited on a metallic or metal-like surface of a three-dimensional structure relative to one or more passivated oxide surfaces. The three-dimensional structure can include, for example, a via or a trench. In some embodiments, the oxide surfaces can be selectively passivated prior to deposition of the metal oxide film. Vapor deposition is then performed to deposit the metal oxide on the metallic surfaces that were not passivated.

[0094] Passivation blocking layer

[0095] The passivation block layer can facilitate selective formation of the passivation layer on the dielectric material relative to the passivation block layer. As described above, a self-assembled monolayer (SAM) can be used to inhibit silanization of the metallic or metal-like surface, thereby facilitating selective passivation of the dielectric surface. The term "block" is thus merely a label and does not necessarily imply 100% passivation of the organic passivation layer deposition. As described elsewhere herein, even imperfect selectivity is sufficient to achieve fully selective structures after an etch-back process.

[0096] Selectivity

[0097] The selective passivation and / or selective deposition can be fully selective or partially selective. A post-deposition etch can be performed after a partially selective process that removes all of the deposited material from above one surface without removing all of the deposited material from above a second surface, thereby forming a fully selective layer. Thus, in some embodiments, the selective deposition need not be fully selective in order to achieve the desired benefits.

[0098] The selectivity of deposition (or passivation) on a first surface, referred to herein as surface A, relative to a second surface, referred to as surface B, can be given by the percentage calculated by [(deposition on surface A) - (deposition on surface B)] / (deposition on surface A). Deposition can be measured in any of a variety of ways. For example, deposition can be given by the measured thickness of the deposited material, or can be given by the measured amount of material deposited. In the embodiments described herein, an oxide surface (A) can be selectively passivated relative to a metallic or metal-like surface (B). With respect to passivation, if the passivation is caused by treatment of the substrate surface rather than deposition of a layer, the amount of passivation can be a measure of the available reaction sites on the substrate surface that have reacted with the passivation agent. Subsequently, a metal oxide layer is selectively deposited on the metallic or metal-like surface (B) relative to the passivation layer above the oxide surface (A).

[0099] In some embodiments, the selectivity of selective formation of a passivation layer on an oxide surface (versus a metal or metallic surface) is greater than about 10%, greater than about 50%, greater than about 75%, greater than about 85%, greater than about 90%, greater than about 93%, greater than about 95%, greater than about 98%, greater than about 99%, or even greater than about 99.5%.

[0100] In some embodiments, the selectivity of deposition of a metal oxide on a metal or metallic surface (versus a passivated oxide surface) is greater than about 10%, greater than about 50%, greater than about 75%, greater than about 85%, greater than about 90%, greater than about 93%, greater than about 95%, greater than about 98%, greater than about 99%, or even greater than about 99.5%.

[0101] In some embodiments, deposition occurs on only one surface and not the other.

[0102] In some embodiments, passivation of an oxide surface versus a metal or metallic surface of a substrate by silylation is at least about 80% selective. In some embodiments, the passivation process is at least about 50% selective. In some embodiments, the passivation process is at least about 10% selective. Those skilled in the art will appreciate that a partial selectivity process can result in full selective passivation of an oxide surface by post-deposition etching to remove any silylation from the metal or metallic surface.

[0103] In some embodiments, deposition of a metal oxide on a metal or metallic surface of a substrate versus a silylated oxide surface of the substrate is at least about 80% selective. In some embodiments, deposition of a metal oxide on a metal or metallic surface of a substrate versus a silylated oxide surface of the substrate is at least about 50% selective. In some embodiments, deposition of a metal oxide on a metal or metallic surface of a substrate versus a silylated oxide surface of the substrate is at least about 10% selective. Those skilled in the art will appreciate that a post-deposition etching (or other treatment) can be performed after a partial selectivity process, which will substantially remove all deposited material from above the silylated oxide surface. In addition, post-deposition treatment can also help tailor the location and / or profile of the selectively deposited layer.

[0104] Selective deposition of metal oxides on metal or metallic surfaces

[0105] Figures 1A-1D An embodiment is schematically illustrated in which a first oxide surface is selectively passivated versus a second metal or metallic surface, and then a metal oxide is selectively deposited on the second metal or metallic surface versus the passivated first oxide surface.

[0106] Figure 1AA substrate is shown having substantially different surfaces exposed. For example, a first surface can include or be defined by a metal, such as cobalt (Co), copper (Cu), tungsten (W), or molybdenum (Mo). A second surface can include or be defined by an oxide, such as a silicon oxide-based layer or a silicon surface having a native oxide formed thereon.

[0107] Figure 1B A substrate is shown after selective passivation of an oxide surface, such as by silanization. Figure 1A For example, a passivation layer can be selectively formed on an oxide surface by exposing the substrate to a silanization agent, such as allyltrimethylsilane (TMS-A), trimethylchlorosilane (TMS-Cl), N-(trimethylsilyl)imidazole (TMS-Im), octadecyltrichlorosilane (ODTCS), hexamethyldisilazane (HMDS), or N-(trimethylsilyl)dimethylamine (TMSDMA).

[0108] Figure 1C A substrate is shown after selective deposition of a metal oxide on a metal surface relative to a passivation layer on an oxide surface. Figure 1B The metal oxide can be, for example, a metal oxide such as aluminum oxide, zirconium oxide, hafnium oxide, titanium oxide, tantalum oxide, yttrium oxide, lanthanum oxide, or other transition metal oxides or mixtures thereof. In some embodiments, the metal oxide is aluminum oxide. In some embodiments, the metal oxide is selectively deposited by a vapor deposition process, such as an atomic layer deposition process. In some ALD processes for selectively depositing a metal oxide, the substrate is alternately and sequentially contacted with a metal reactant and an oxygen reactant. For example, aluminum oxide can be selectively deposited on a metal or metallic surface relative to a passivated surface by an ALD process comprising alternately and sequentially contacting the substrate with an aluminum reactant, such as trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), dimethylisopropylaluminum (DMAI), tri(tert-butyl)aluminum (TTBA), tri(isopropylal)aluminum (TIPA), or triethylaluminum (TEA), and an oxygen reactant, such as water.

[0109] As described above, any metal oxide deposited on the passivation layer can be removed by a post-deposition treatment such as an etch-back process. Because the metal oxide is selectively deposited on the metal surface, any metal oxide left on the passivation surface will be thinner than the metal oxide formed on the metal surface. Thus, the post-deposition treatment can be controlled to remove all of the metal oxide above the surface including the passivation layer without removing all of the metal oxide above the metal surface. Repeating the selective deposition and etch-back in this manner can result in an increase in the thickness of the metal oxide on the metal surface with each deposition and etch cycle. Repeating the selective deposition and etch-back in this manner can also result in an overall increase in the selectivity of the metal oxide on the metal or metallic surface because each deposition and etch cycle leaves a clean passivation layer on which selective metal oxide deposition nucleates poorly. In other embodiments, the metal oxide material can be removed during a subsequent removal of the passivation layer. For example, a direct etch or lift-off method can be used to remove the metal oxide from the passivation layer surface in the selective deposition and removal cycles.

[0110] Figure 1D A substrate is shown after a post-deposition treatment such as removal of the passivation layer from the oxide surface by an etch process Figure 1C In some embodiments, the etch process can include exposing the substrate to a plasma. In some embodiments, the plasma can include oxygen atoms, oxygen radicals, oxygen plasma, or combinations thereof. In some embodiments, the plasma can include hydrogen atoms, hydrogen radicals, hydrogen plasma, or combinations thereof. In some embodiments, the plasma can include inert gas species, such as Ar or He species. In some embodiments, the plasma can consist essentially of inert gas species. In some cases, the plasma can include other species, such as nitrogen atoms, nitrogen radicals, nitrogen plasma, or combinations thereof. In some embodiments, the etch process can include exposing the substrate to an etchant including oxygen, such as O3. In some embodiments, the substrate can be exposed to the etchant at a temperature between about 30 °C and about 500 °C, or between about 100 °C and about 400 °C. In some embodiments, the etchant can be supplied in one continuous pulse or in multiple pulses. As described above, the passivation layer removal can be used in the selective deposition and removal cycles to lift off any remaining metal oxide from above the oxide layer, either with complete removal of the passivation layer or with partial removal of the passivation layer.

[0111] Additional treatments, such as thermal or chemical treatments, can be performed before, after, or between the foregoing processes. For example, the treatments can alter the surface or remove a portion of the metal, silicon oxide, passivation, and metal oxide surfaces exposed at various stages of the process. In some embodiments, the substrate can be pre-treated or cleaned prior to or at the beginning of the process. In some embodiments, the substrate can be subjected to a plasma cleaning process as described above.

[0112] While certain embodiments and examples have been discussed, those skilled in the art will understand that the scope of the claims extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses and obvious modifications and equivalents thereof.

Claims

1. A method for selectively depositing a metal oxide on a metal surface of a substrate relative to a transition metal oxide surface of the substrate, wherein, The metal surface is an Al, Cu, Co, Ni, W, Nb, Fe, or Mo surface, and the method comprises, in sequence: A passivation barrier layer is formed on the metal surface; Selectively passivating the transition metal oxide surface relative to the metal surface, wherein selective passivation of the transition metal oxide surface includes exposing the transition metal oxide surface to a silanizing agent; Removal of the passivation barrier layer from the metal surface; and The metal oxide is selectively deposited on the metal surface by the self-gas phase reactant relative to the passivated transition metal oxide surface. The gas-phase reactants include hydrophobic metal reactants, which comprise one or more hydrophobic ligands, and At least one of the one or more hydrophobic ligands includes C.

2. The method according to claim 1, wherein the silanizing agent comprises allyltrimethylsilane (TMS-A), trimethylchlorosilane (TMS-Cl), N-(trimethylsilyl)imazole (TMS-Im), octadecyltrichlorosilane (ODTCS), hexamethyldisilazane (HMDS), or N-(trimethylsilyl)dimethylamine (TMSDMA).

3. The method of claim 1, wherein the silanizing agent comprises an alkylaminosilane.

4. The method according to claim 3, wherein the alkylaminosilane has the formula (R I )3Si(NR II R III ), where R I R is a straight-chain or branched C1-C5 alkyl group or a straight-chain or branched C1-C4 alkyl group. II R is a straight-chain or branched C1-C5 alkyl group, a straight-chain or branched C1-C4 alkyl group, or hydrogen. III It is a straight-chain or branched C1-C5 alkyl group or a straight-chain or branched C1-C4 alkyl group.

5. The method of claim 1, wherein the silanizing agent comprises silane.

6. The method of claim 5, wherein the silane has the general formula (R I )3SiA, where R I A is a straight-chain or branched C1-C5 alkyl group or a straight-chain or branched C1-C4 alkyl group, and A is any ligand that can react with a silicon-containing surface.

7. The method of claim 1, wherein the metal oxide comprises a dielectric transition metal oxide.

8. The method of claim 1, wherein the metal oxide comprises aluminum oxide, zirconium oxide, hafnium oxide, titanium oxide, tantalum oxide, yttrium oxide, lanthanum oxide or other transition metal oxides or mixtures thereof.

9. The method of claim 8, wherein the metal oxide comprises aluminum oxide.

10. The method of claim 9, wherein the alumina is deposited using an aluminum precursor comprising trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), aluminum dimethylisopropoxide (DMAI), tri(tert-butyl)aluminum (TTBA), tri(isopropanol)aluminum (TIPA), or triethylaluminum (TEA).

11. The method of claim 10, wherein the alumina is deposited using an aluminum precursor comprising aluminum dimethyl isopropoxide (DMAI).

12. The method of claim 9, wherein the alumina is deposited using an aluminum precursor comprising a heterocoordinated aluminum compound comprising alkyl groups and various ligands.

13. The method of claim 12, wherein the different ligands are halides.

14. The method of claim 9, wherein the alumina is deposited using an aluminum precursor comprising an aluminum alkyl compound, the aluminum alkyl compound comprising two distinct alkyl groups as ligands.

15. The method of claim 9, wherein the alumina is deposited using an aluminum precursor comprising an organoaluminum metal compound or an organometallic aluminum compound.

16. The method of claim 9, wherein the alumina is deposited by an atomic layer deposition (ALD) process, the ALD process comprising alternately and sequentially contacting the substrate with a first reactant comprising trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), aluminum dimethylisopropoxide (DMAI), tri(tert-butyl)aluminum (TTBA), tri(isopropanol)aluminum (TIPA), or triethylaluminum (TEA) and a second reactant comprising water.

17. The method of claim 1, wherein the metal oxide layer is selectively deposited by an atomic layer deposition (ALD) process.

18. The method of claim 17, wherein the atomic layer deposition (ALD) process comprises alternating and sequentially contacting the substrate with a first metal reactant and a second oxygen reactant.

19. The method of claim 1, wherein the passivation blocking layer comprises a self-assembled monolayer (SAM).

20. The method according to claim 1, wherein, At least one of the hydrophobic ligands is composed of C and H.

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