Selective deposition of silicon oxide on metal surfaces

Abstract

Methods for selectively depositing a silicon oxide film on a metallic or metallic surface relative to a dielectric surface are provided. The dielectric surface of the substrate may be selectively passivated relative to a metallic or metallic surface, such as by exposing the substrate to a silylating agent. Silicon oxide is then selectively deposited on the metal or metallic surface relative to the passivated oxide surface by contacting the metal surface with a metal catalyst and a silicon precursor comprising a silanol.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 202110323241.X filed on March 26, 2021 (applicant: ASM IP Private Holding Co., Ltd., invention name: Selective deposition of silicon oxide on metal surfaces). Technical Field

[0002] The present disclosure generally relates to the selective deposition of silicon oxide on a metal or metallic surface of a substrate relative to a dielectric surface of the substrate. Background Art

[0003] The ever-shrinking device dimensions in semiconductor manufacturing require new and innovative processing methods. Conventionally, patterning in semiconductor processing involves a subtractive process in which a blanket layer is deposited, masked by photolithography, and etched through openings in the mask. Additive patterning is also known, in which a 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.

[0004] 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. Most importantly, it reduces photolithography steps, thereby lowering processing costs. Selective deposition also enables enhanced scaling in narrow structures.

[0005] Thin films containing silicon dioxide are used in many different applications in microelectronics, for example as dielectric materials. Silicon dioxide is one of the most commonly used dielectric materials in silicon microelectronics. Summary of the Invention

[0006] In some aspects, a method for selectively depositing a silicon oxide film on a metal or metallic surface relative to a dielectric surface is provided. In some embodiments, the method for selectively depositing silicon oxide on a metal surface of a substrate relative to the dielectric surface of the substrate comprises, in order: contacting the substrate with a passivating agent; contacting the metal surface with a metal catalyst; and contacting the metal surface with a silicon reactant comprising a silanol. In some embodiments, the metal surface comprises one or more of Al, Cu, Co, Ni, W, Nb, Fe, and Mo. In some embodiments, the dielectric surface comprises silicon oxide. In some embodiments, contacting the substrate with the passivating agent results in selectively passivating the dielectric surface relative to the metal surface. In some embodiments, the passivating agent is a silylating agent. In some embodiments, the silylating agent comprises an alkylaminosilane. In some embodiments, the alkylaminosilane has the formula (R I )3Si(NR II R III), wherein R I is a straight-chain or branched C1-C5 alkyl group or a straight-chain or branched C1-C4 alkyl group, and R II is a straight-chain or branched C1-C5 alkyl group, a straight-chain or branched C1-C4 alkyl group or hydrogen, and R III is a straight-chain or branched C1-C5 alkyl group or a straight-chain or branched C1-C4 alkyl group. 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).

[0007] In some embodiments, the metal catalyst comprises trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), dimethylaluminum isopropoxide (DMAI), tris(tert-butyl)aluminum (TTBA), tris(isopropanol)aluminum (TIPA) or triethylaluminum (TEA). In some embodiments, the metal catalyst is a metal compound comprising Zn, Mg, Mn, La, Hf, Al, Zr, Ti, Sn or Ga. In some embodiments, the metal catalyst is a metal halide, an organometallic compound or a metal organic compound.

[0008] In some embodiments, the silicon reactant comprises tris(tert-butoxy)silanol (TBS), tris(isopropoxy)silanol (TIS) or tris(tert-pentyloxy)silanol (TPS).

[0009] In some embodiments, a passivation blocking layer is formed on the metal surface before contacting the substrate with the passivating agent. In some embodiments, the passivation blocking layer comprises a polymer or a self-assembled monolayer (SAM).

[0010] In some embodiments, the selectivity of silicon oxide deposition on the catalyzed metal surface relative to the passivated dielectric surface is greater than about 50%.

[0011] In some embodiments, depositing silicon oxide selectively on a metallic surface of a substrate relative to a dielectric surface of the substrate includes a deposition supercycle that includes contacting the substrate with a silylating agent and performing one or more silicon oxide deposition subcycles that include alternately and sequentially contacting the substrate with a metal catalyst and a silanol. In some embodiments, the silylating agent is N-(trimethylsilyl)dimethylamine. In some embodiments, the metal catalyst includes trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), dimethylaluminum isopropoxide (DMAI), tris(tert-butyl)aluminum (TTBA), tris(isopropanol)aluminum (TIPA), or triethylaluminum (TEA).

[0012] In some embodiments, the metal catalyst is a metal compound that includes Zn, Mg, Mn, La, Hf, Al, Zr, Ti, Sn, or Ga. In some embodiments, the metal catalyst is a metal halide, an organometallic compound, or a metal organic compound. In some embodiments, the silane is tris(tert-pentyloxy) silanol. In some embodiments, the silicon oxide deposition subcycle is repeated two or more times in the deposition supercycle. In some embodiments, the substrate is contacted with the silanol two or more times in at least one silicon oxide deposition subcycle. In some embodiments, the deposition supercycle is repeated two or more times.

[0013] In some embodiments, a method of depositing silicon oxide selectively on a metallic surface of a substrate relative to a dielectric surface of the substrate includes alternately and sequentially contacting the substrate with a silylating agent that includes allyltrimethylsilane (TMS-A), trimethylchlorosilane (TMS-Cl), N-(trimethylsilyl)imidazole (TMS-Im), octadecyltrichlorosilane (ODTCS), hexamethyldisilazane (HMDS), or N-(trimethylsilyl)dimethylamine (TMSDMA); trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), dimethylaluminum isopropoxide (DMAI), tris(tert-butyl)aluminum (TTBA), tris(isopropanol)aluminum (TIPA), or triethylaluminum (TEA); and tris(tert-pentyloxy) silanol. Description of the Drawings

[0014] Figure 1 is a flowchart schematically illustrating a deposition method of depositing silicon oxide selectively on a metallic surface relative to a dielectric surface.

[0015] Figure 2A is a schematic cross-section of a portion of a substrate having a first dielectric surface and a second adjacent metallic surface.

[0016] Figure 2B after selective passivation of the dielectric surfaceFigure 2A Schematic cross-section of a substrate.

[0017] Figure 2C After selective deposition of an aluminum catalyst on a metal surface Figure 2B Schematic cross-section of a substrate.

[0018] Figure 2D After selective deposition of silica on a metal surface Figure 2C Schematic cross-section of a substrate.

[0019] Figure 2E After removing a passivation material from an oxide surface Figure 2D Schematic cross-section of a substrate. Detailed Description

[0020] Silica films formed by the methods described herein, such as silicon dioxide films (e.g., SiO2 films), can be used in a variety of situations. Silica films, such as silicon dioxide films (e.g., SiO2 films), are, for example, used in various semiconductor devices, including CMOS, DRAM, flash memory, and magnetic head applications. Silica, such as silicon dioxide (e.g., SiO2), is also commonly used as a gate dielectric in CMOS, as an electrical isolation layer, and as a gap-fill layer. A silica film, such as a silicon dioxide film (e.g., SiO2 film), can be deposited by exposing silanol to a surface containing a suitable catalyst. The catalyst prepares the surface to react with silanol, resulting in catalytic growth of silica on the substrate surface.

[0021] In some embodiments, silica is selectively deposited over a first metal (or metallic) surface relative to a second dielectric surface, such as an oxide surface, by using a passivating agent in combination with a catalyst. In some embodiments, the dielectric surface can be selectively passivated relative to the metal surface, for example, by silylation. Subsequently, a catalyst is selectively deposited on the metal surface relative to the dielectric surface. The catalyst can be, for example, a metal catalyst, as described in more detail below. Then a silica layer is selectively deposited on the metal surface relative to the passivated dielectric surface by contacting the substrate with a silicon reactant, such as silanol. In some embodiments, the catalyst is not deposited on the metal surface after passivation of the dielectric surface and the silica layer is deposited. The silica layer can be deposited by a cyclic chemical vapor deposition process, where the substrate is alternately contacted with the catalyst and silanol until a silica film of the desired thickness has been selectively deposited. In some embodiments, the passivation step can be omitted.

[0022] In some embodiments, a dielectric surface such as an oxide surface on a substrate is silylated 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), a metal catalyst as described herein is selectively deposited on the metal surface of the same substrate, and silica is subsequently selectively deposited on the metal surface of the substrate relative to the passivated dielectric surface. For example, a silica layer can be selectively deposited on a metal surface relative to an adjacent dielectric surface such as a metal oxide surface, a silica surface, or a low-k surface, for example by using allyltrimethylsilane (TMS-A), trimethylchlorosilane (TMS-Cl), N-(trimethylsilyl)imidazole (TMS-Im), octadecyltrichlorosilane (ODTCS), hexamethyldisilazane (HMDS), or N-(trimethylsilyl)dimethylamine (TMSDMA) as a passivating agent, trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), dimethylaluminum isopropoxide (DMAI), tris(tert-butyl)aluminum (TTBA), tris(isopropanol)aluminum (TIPA), or triethylaluminum (TEA) as an aluminum catalyst, and a silanol such as tris(tert-pentyloxy)silanol as a silicon reactant.

[0023] In some embodiments, the metal or metallic surface of the substrate comprises an elemental metal or a metal alloy, and a second different surface of the substrate comprises a dielectric material such as an oxide. In some embodiments, the dielectric surface and the metal surface are adjacent to each other. Examples of possible dielectric materials include silica-based materials, including grown or deposited silicon dioxide, doped and / or porous oxides, native oxides on silicon, etc. In some embodiments, the dielectric material comprises a metal oxide. In some embodiments, the dielectric material comprises a low-k material.

[0024] The surface of a dielectric material can be selectively passivated relative to a metal or metallic surface, such as by selective silylation. In some embodiments, the dielectric surface is contacted with a vapor-phase passivating agent such as vapor-phase allyltrimethylsilane (TMS-A), trimethylchlorosilane (TMS-Cl), N-(trimethylsilyl)imidazole (TMS-Im), octadecyltrichlorosilane (ODTCS), hexamethyldisilazane (HMDS), or N-(trimethylsilyl)dimethylamine (TMSDMA). The substrate can be contacted with a sufficient amount of the passivating agent for a sufficient period of time such that the dielectric surface is selectively passivated with silicon species. In some embodiments, both surfaces are contacted with the vapor-phase passivating agent and the dielectric surface is selectively passivated relative to the metal or metallic surface. In some embodiments, the dielectric surface is not passivated with a self-assembled monolayer (SAM).

[0025] A catalyst is selectively formed on the metal surface relative to the dielectric surface, such as by contacting the substrate with a metal catalyst compound. In some embodiments, the catalyst is a metal catalyst. In some embodiments, both the metal surface and the dielectric surface are contacted with the metal catalyst compound. The metal surface containing the catalyst species may be referred to herein as a "catalyzed metal surface". In some embodiments, the substrate is contacted with a metal catalyst as described below. The catalyst can be, for example, a metal compound containing Zn, Mg, Mn, La, Hf, Al, Zr, Ti, Sn, or Ga. In some embodiments, the catalyst is a metal halide, an organometallic, or a metal-organic compound. In some embodiments, the catalyst can be a metal oxide. In some embodiments, the catalyst is a compound containing boron. In some embodiments, the metal catalyst is an aluminum catalyst, which includes trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), dimethylaluminum isopropoxide (DMAI), tris(tert-butyl)aluminum (TTBA), tris(isopropanol)aluminum (TIPA), or triethylaluminum (TEA). In some embodiments, the catalyst is a zirconium compound, such as Zr-DO4. In some embodiments, the catalyst is tetra(ethylmethylamino)zirconium (TEMAZ). In some embodiments, the catalyst is ZrCl4. In some embodiments, the catalyst is a lanthanum compound, such as tris(isopropyl-cyclopentadienyl)lanthanum (LA(iPrCp)3). In some embodiments, the catalyst is a titanium compound, such as titanium isopropoxide (TTIP) or TiCl4. In some embodiments, the catalyst is a gallium compound, such as trimethylgallium (TMG). In some embodiments, the catalyst is a hafnium compound, such as HfCl4 or Hf(NO3)4.

[0026] In some embodiments, the catalyst may preferentially deposit on the metal surface relative to the dielectric surface. In some embodiments, the catalyst preferentially deposits on the metal surface relative to the passivated dielectric surface. In some embodiments, the passivating agent on the dielectric surface will inhibit or prevent the deposition of the aluminum catalyst on the dielectric surface. In some embodiments, a single exposure to the passivating agent can prevent the deposition of the catalyst on the dielectric surface in 1, 2, 5, 10, 20, 30, 40, or 50 or more cycles in which the substrate is contacted with the catalyst. In some embodiments, the dielectric surface is not passivated, and the catalyst selectively deposits on the metal surface in the absence of a passivating material on the dielectric surface. In some embodiments, no catalyst is employed, such as when the metal itself on a metal or metallized surface can catalyze the deposition of silicon oxide.

[0027] After depositing the catalyst on the metal or metallized surface, a silicon oxide layer is selectively deposited on the metal or metallized surface relative to the passivated dielectric surface. For example, the substrate can be exposed to a silicon precursor, such as silanol. In some embodiments, the substrate is exposed only to the silicon precursor, while in some embodiments, the substrate is exposed to the silicon precursor and an oxygen precursor such as H2O. The silicon precursor can react with the surface containing the aluminum catalyst to form silicon oxide. For example, the substrate can be contacted with a silicon reactant containing silanol such that the silanol decomposes at the catalyst atoms on the metal or metallized surface, resulting in the selective growth of silicon oxide on the metal or metallized surface relative to the dielectric surface.

[0028] In some embodiments, the substrate is alternately and sequentially contacted with the passivating agent, the catalyst, and the silanol reactant in one or more deposition supercycles. The deposition supercycle can be repeated multiple times to selectively deposit a silicon oxide film of a desired thickness on the metal surface relative to the dielectric surface. Refer to Figure 1, in some embodiments, in a complete deposition supercycle 100, the substrate is first contacted with a passivating agent 110 such as a silylating agent. Excess passivating agent can be removed from the substrate surface. A silicon oxide deposition subcycle 120 is performed, in which the substrate is contacted with a catalyst 130 and a silicon precursor such as silanol 140. As described above, in some embodiments, in addition to the silicon reactant, the substrate is also contacted with an oxygen reactant such as H2O. After each contact step 130 and 140, excess catalyst and silanol can be removed from the substrate surface. The subcycle can be repeated 150 or more times in a single deposition supercycle 100. In some embodiments, one, two, three, or more silicon oxide deposition subcycles are performed in each deposition supercycle 100, in which the substrate is contacted alternately and sequentially with the catalyst 130 and the silanol reactant 140. That is, each time the substrate is contacted with the passivating agent 110, multiple silicon oxide deposition subcycles 120 can be performed. In some embodiments, the silicon oxide deposition subcycle 120 is repeated up to fifty times before starting another deposition supercycle 100 by contacting the substrate with the passivating agent. In some embodiments, the passivation layer is removed after the deposition subcycle and before contacting the substrate with the passivating agent 110, such as by plasma etching, for example by contacting the substrate with an H2 plasma. Thus, the passivation layer can be updated one or more times during the deposition process. In some embodiments, the passivation layer is not removed in every deposition supercycle 100 but only in one or more deposition supercycles, such as in the last deposition supercycle. The deposition supercycle 100 can be repeated until a silicon oxide film of a desired thickness has been selectively formed on the metal surface. In some embodiments, the passivating agent is provided only once during the deposition process.

[0029] In some embodiments, the metal or metallic surface on which the metal oxide is selectively deposited is at least partially adjacent to a dielectric surface that is selectively passivated. For example, at least a portion of the metal or metallic surface can be adjacent to a dielectric surface such as an oxide surface.

[0030] In some embodiments, a passivation blocking layer, such as a self-assembled monolayer (SAM), can be provided on the metal or metallic surface before forming the passivation layer on the dielectric surface such as an oxide surface. The passivation blocking layer can promote the selectivity of the dielectric surface to passivation such as silylation, and the passivation blocking layer can be removed thereafter to allow the selective deposition of the metal catalyst and silicon oxide on the metal or metallic surface relative to the silylated dielectric surface.

[0031] A passivation layer (e.g., silylation) on a dielectric surface such as an oxide surface can be removed after selectively depositing a silicon oxide layer above a metal or metallic surface. Conditions can be selected to avoid damaging surrounding materials on the substrate. In some embodiments, the passivation layer (e.g., silylation) on the dielectric surface can be removed and renewed at one or more time intervals during the deposition of the silicon oxide layer. For example, the passivation layer can be removed at one or more time intervals during the deposition process, such as by exposure to an H2 plasma, and then again exposed to a silylating agent before further silicon oxide deposition. In some embodiments, the passivation layer is removed and renewed in each cycle.

[0032] Examples of suitable reactors that can be used in the selective deposition processes described herein include commercially available atomic layer deposition (ALD) equipment. In addition to ALD reactors, many other types of reactors capable of growing an organic passivation layer can also be employed, including chemical vapor deposition (CVD) reactors, vapor deposition polymerization (VDP) reactors, and molecular layer deposition (MLD) reactors.

[0033] Substrate surface

[0034] According to some aspects of the present disclosure, selective deposition can be used to preferentially deposit a film of interest, such as a silicon oxide film, on a metal or metallic surface relative to an oxide surface or other dielectric surface. Figure 2A Such a substrate is schematically shown. In some embodiments, the two surfaces on the substrate are at least partially adjacent to each other. Selective passivation of the oxide surface relative to the metal or metallic surface, such as selective silylation of the oxide surface, will facilitate subsequent selective deposition of a metal catalyst on the metal or metallic surface, followed by selective deposition of a silicon oxide layer on the metal or metallic surface relative to the silylated oxide surface.

[0035] In some embodiments, one of the surfaces can be a conductive metal or metallic surface of the substrate, while the other dielectric surface can be a non-conductive oxide surface of the substrate. In some embodiments, the non-conductive oxide surface contains -OH groups, such as a silicon oxide-based surface (e.g., a low-k material, including grown and deposited silicon oxide materials and native oxide on silicon). The oxide surface can be selectively passivated relative to the metal or metallic surface by exposure to a silylating agent. This is followed by exposure to a metal catalyst, and then silicon oxide can be selectively deposited on the metal or metallic surface relative to the silylated oxide surface.

[0036] The material difference between two substrate surfaces enables a vapor deposition method to selectively passivate an oxide surface relative to a metal or metallic surface. In some embodiments, a cyclic vapor deposition is used, such as a cyclic chemical vapor deposition (CVD) or atomic layer deposition (ALD) process. In some embodiments, selectivity of the passivation layer can be achieved in the absence of a passivation / blocking agent (to receive a lesser passivation layer) on a metal or metallic surface and / or in the absence of a catalyst on the surface of a dielectric layer to receive a greater passivation layer. For example, in an embodiment where the first surface is an oxide and the second surface is metallic, the oxide layer can be selectively silylated relative to the metal or metallic surface without pretreatment of the oxide surface or the metal or metallic surface.

[0037] In some embodiments, the metal or metallic surface is first treated to inhibit passivation (such as silylation) of the surface. In some embodiments, the passivation blocking layer is a polymer layer. In some embodiments, a passivation blocking self-assembled monolayer (SAM) can be first formed above the metal or metallic surface relative to the oxide surface, thereby facilitating selective deposition of the passivation layer on the oxide surface relative to the SAM covering the metallic surface. The passivation inhibitor can be removed after selective passivation and before deposition of the catalyst and subsequent deposition of silicon oxide. After selective deposition of the passivation layer, selective deposition of materials of interest such as a catalyst and / or silicon oxide can be performed on the non-passivated metal or metallic surface relative to the passivated surface.

[0038] As used herein, unless otherwise specified, if a surface is referred to as a metal surface herein, it can be a metal or metallic surface. In some embodiments, the metal or metallic surface can include surface oxidation. In some embodiments, the material of the metal surface is 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 metal oxides such as conductive metal oxides, metal nitrides, metal carbides, metal borides, or combinations thereof. For example, the metal or metallic surface can include RuO x 、NbC x 、NbB x 、NiO x 、CoO x 、NbO x 、MoO x 、WO x, WNC x , one or more of TaN or TiN.

[0039] In some embodiments, the metal or metallic surface is a surface that is acceptable as a precursor for use in the selective deposition process of an aluminum catalyst as described herein or that can coordinate therewith.

[0040] As described above, in some embodiments, the metal or metallic surface may include a passivation blocking layer thereabove. That is, in some embodiments, the metal or metallic surface may 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. After forming a passivation layer on the dielectric surface, the passivation blocking layer can be removed if necessary or desired.

[0041] Passivation of the substrate surface

[0042] In some embodiments, the oxide or other dielectric surface of the substrate can be passivated. In some embodiments, the passivation is selective for the oxide surface relative to another surface, such as a metal or metallic surface on the same substrate (see, for example Figure 2B ). In some embodiments, the oxide surface is silylated by exposure to a gas-phase silylating agent one or more times. For example, in the passivation step, the silylating agent can be introduced into the reaction space and contacted with the substrate 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 silylacetamide, a silylcarbodiimide, an allylsilane, 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.

[0043] In some embodiments, the silylating agent is an alkylaminosilane. For example, the oxide surface of a substrate can be contacted with an alkylaminosilane having the formula (R I )3Si(NR II R III ), where R I is a straight-chain or branched C1-C5 alkyl group or a straight-chain or branched C1-C4 alkyl group, R II is a straight-chain or branched C1-C5 alkyl group, a straight-chain or branched C1-C4 alkyl group, or hydrogen, and R III is a straight-chain or branched C1-C5 alkyl group or a straight-chain or branched C1-C4 alkyl group.

[0044] 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 straight-chain or branched C1-C5 alkyl group or a straight-chain or branched C1-C4 alkyl group, and A is any ligand capable of reacting with a silicon-containing surface.

[0045] The silylating agent can be provided to the reaction chamber containing the substrate as a single pulse or as a series of multiple pulses. In some embodiments, the silylating agent is provided as a single long pulse or as multiple shorter pulses. The pulses can be provided sequentially. In some embodiments, the silylating agent is provided as 1 to 25 pulses over about 0.1 to about 60 seconds. In some embodiments, the silylating agent is provided as a single pulse over about 0.1 to about 60 seconds, about 1 to about 30 seconds, or about 25 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 purge can last, for example, about 1 to about 30 seconds or more. Purging the reaction chamber refers to removing the gas-phase passivating agent and / or gas-phase by-products, if any, from the reaction chamber, such as by evacuating the chamber with a vacuum pump and / or replacing the gas in the reactor with an inert gas such as argon or nitrogen. In some embodiments, the substrate is removed from the reaction space containing the passivating agent.

[0046] In some embodiments, the temperature of the silylation process can be, for example, about 50 to about 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 about 10 Torr or about 0.1 to about 10 Torr.

[0047] In some embodiments, the silylation process can be carried out in-situ, i.e., in the same reaction chamber as, for example, a subsequent deposition process of selectively depositing an aluminum catalyst on a non-silylated surface relative to the silylated surface and / or selectively depositing silica subsequently on the non-silylated surface relative to the silylated surface. However, in some embodiments, silylation can be carried out in a reaction chamber separate from one or more subsequent processing steps. In some embodiments, the reaction chamber in which silylation is carried out is part of a cluster tool, the cluster tool including one or more additional reaction chambers. For example, such a cluster tool can include additional reaction chambers for depositing an aluminum catalyst, depositing silica, and / or for etching one or more layers. In some embodiments, the cluster tool includes separate modules for pre-treatment, silylation of the oxide surface, selective deposition of the catalyst, selective deposition of silica, and subsequent post-deposition processing, such as etching to remove silylation or post-deposition plasma cleaning. In some embodiments, the same module can be used for two or more processes.

[0048] In some embodiments, the substrate can be pre-treated or cleaned before or at the start of one or more of the passivation and / or selective deposition processes. In some embodiments, the substrate can be subjected to a plasma cleaning process before or at the start of the selective passivation and / or selective deposition process. In some embodiments, the plasma cleaning process may not include ion bombardment, or may include a relatively small amount of ion bombardment. In some embodiments, the substrate surface can be exposed to plasma, radicals, excited species, and / or atomic species before or at the start of the passivation process and / or selective metal oxide deposition process. In some embodiments, the substrate surface can be exposed to a hydrogen plasma, radicals, or atomic species before or at the start of the selective passivation process and / or selective metal oxide deposition process.

[0049] In some embodiments, the dielectric surface is not passivated before selectively depositing a catalyst on the metal surface relative to the dielectric surface.

[0050] Selective deposition of a metal catalyst on a metal or metallic surface relative to an oxide surface

[0051] Catalysts for subsequent deposition of silicon oxide can be selectively deposited on the metallic or metalloid surface of a substrate relative to the dielectric surface of the substrate. This surface containing the catalyst can be referred to as a catalyzed metal surface. In some embodiments, passivation of the dielectric surface is not necessary, and the catalyst is selectively deposited on the metal surface relative to the dielectric surface, where the dielectric surface is not passivated. However, in some embodiments, the selective deposition of the catalyst is facilitated or improved by passivation of the dielectric surface as described above. Thus, in some embodiments, the catalyst is selectively deposited on the metallic or metalloid surface relative to the passivated dielectric surface. As Figure 2C shown, in some embodiments, an aluminum catalyst is selectively deposited on a metal surface relative to a dielectric surface passivated with a silylation compound as described herein.

[0052] After selectively forming a passivation layer on the dielectric surface, in some embodiments, the catalyst is selectively deposited on the second surface by contacting the substrate with a catalyst compound. The catalyst forms catalytic sites up to a monolayer on the metal substrate surface. The catalyst compound preferably catalyzes the reaction to form silicon oxide from a gas-phase silanol reactant as described below. Briefly, the substrate is exposed to a silanol, such as TPS, and a silicon oxide film, such as a silicon dioxide film (e.g., SiO2 film), is formed, which typically comprises multiple molecular layers. If necessary, the cycles of exposure to the catalyst and silanol can be repeated to deposit a silicon dioxide film of a desired thickness. In some embodiments, the concentration of the silanol can be controlled to achieve a desired deposition rate. In some embodiments, the substrate temperature can be controlled to achieve a desired deposition rate. In some embodiments, a catalyst is not necessary, and the metal surface itself will catalyze the deposition of silicon oxide from the silanol.

[0053] In some embodiments, the catalyst is a metal catalyst. The catalyst can be, for example, a metal compound comprising Zn, Mg, Mn, La, Hf, Al, Zr, Ti, Sn, or Ga. In some embodiments, the catalyst is a metal halide, an organometallic, or a metal-organic compound.

[0054] In some embodiments, the catalyst contains boron. In some embodiments, the catalyst is an alkylaluminum, alkylboron, or alkylzinc compound capable of reacting with a hydrophobic surface. For example, the catalyst can comprise trimethylaluminum (TMA), triethylboron (TEB), or diethylzinc.

[0055] In some embodiments, the catalyst contains a compound having the formula MR x A 3-x where x is from 1 to 3 and R is C 1-A C5 alkyl ligand, M is B, Zn, Mg, Mn, La, Hf, Al, Zr, Ti, Sn or Ga, and A is a halide, alkylamine, amino group, silyl group or a derivative thereof. In some embodiments, R is a C1-C3 alkyl ligand. In some embodiments, R is a methyl or ethyl group. In some embodiments, M is boron. In some embodiments, the catalyst is ZnR x A 2-x , where x is from 1 to 2, R is a C1-C5 alkyl ligand, and A is a halide, alkylamine, amino group, silyl group or a derivative thereof. In some embodiments, R is a C1-C3 alkyl ligand. In some embodiments, R is a methyl or ethyl group.

[0056] In some embodiments, the catalyst is an aluminum catalyst. Examples of Al compounds that can be used include trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), dimethylaluminum isopropoxide (DMAI), tris(tert-butyl)aluminum (TTBA), tris(isopropanol)aluminum (TIPA), or triethylaluminum (TEA). In some embodiments, the aluminum catalyst comprises a heterocoordinated aluminum compound. In some embodiments, the heterocoordinated aluminum compound comprises an alkyl group and another ligand, such as a halide, for example Cl. In some embodiments, the aluminum catalyst comprises dimethylaluminum chloride. In some embodiments, the aluminum catalyst comprises an alkyl precursor having two different alkyl groups as ligands. In some embodiments, the aluminum compound is aluminum isopropoxide. In some embodiments, the aluminum catalyst comprises a metal-organic compound. In some embodiments, the aluminum catalyst comprises an organometallic compound. In some embodiments, the aluminum catalyst is an aluminum compound such as trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), dimethylaluminum isopropoxide (DMAI), tris(tert-butyl)aluminum (TTBA), tris(isopropanol)aluminum (TIPA), or triethylaluminum (TEA).

[0057] In some embodiments, the catalyst is a zirconium compound, such as Zr-DO4. In some embodiments, the catalyst is tetrakis(ethylmethylamino)zirconium (TEMAZ). In some embodiments, the catalyst is ZrCl4.

[0058] In some embodiments, the catalyst is a lanthanum compound, such as tris(isopropyl-cyclopentadienyl)lanthanum (LA(iPrCp)3).

[0059] In some embodiments, the catalyst is a titanium compound, such as titanium isopropoxide (TTIP) or TiCl4.

[0060] In some embodiments, the catalyst is a gallium compound, such as trimethylgallium (TMG).

[0061] In some embodiments, the catalyst is a hafnium compound, such as HfCl4 or Hf(NO3)4.

[0062] The catalyst can be provided to the reaction chamber containing the substrate as a single pulse or as a series of multiple pulses. In some embodiments, the catalyst is provided as a single long pulse or as multiple shorter pulses. The pulses can be provided sequentially. In some embodiments, the catalyst is provided as 1 to 25 pulses over a period of about 0.1 to about 60 seconds. In some embodiments, the catalyst is provided as a single pulse over a period of about 0.1 to about 60 seconds, about 1 to 30 seconds, or about 25 seconds. Between pulses, excess catalyst can be removed from the reaction space. For example, the reaction chamber can be evacuated and / or purged with an inert gas. The purge can last, for example, about 1 to 30 seconds or more. Purging refers to removing gaseous catalyst and / or gaseous by-products, if any, from the reaction chamber, such as by evacuating the chamber with a vacuum pump and / or displacing the gas in the reaction chamber with an inert gas. In some embodiments, the gaseous catalyst is removed from the substrate surface by moving the substrate away from the reaction space containing the gaseous catalyst.

[0063] In some embodiments, the temperature for selective catalyst deposition can be, for example, about 50 to about 500 °C, or about 100 to about 300 °C. In some embodiments, the deposition temperature is between about 50 °C and about 400 °C. In some embodiments, the deposition temperature is above about 100 °C and the catalytic chemical is an alkylaluminum compound, such as TMA. In some embodiments, the catalytic chemical is an alkylboron compound, such as TEB, and the deposition temperature is between about 50 °C and about 400 °C, between about 100 °C and about 350 °C, or between about 100 °C and about 300 °C. In some embodiments, the catalytic chemical is an alkylboron compound and the temperature is above about 100 °C. In some embodiments, the deposition temperature is above about 300 °C and the catalytic chemical is TEB.

[0064] In some embodiments, the catalyst comprises a metal compound selectively deposited by contacting the substrate with a metal precursor and an oxygen reactant. In some embodiments, the catalyst comprises a metal oxide. In some embodiments, the metal compound is selectively deposited by an ALD process. In some embodiments, the substrate is contacted with a first metal precursor and a second oxygen-containing reactant simultaneously or sequentially in one, two, or more deposition cycles. In some embodiments, the deposition process comprises multiple deposition cycles in which the substrate is contacted alternately and sequentially with the first metal precursor and the second reactant.

[0065] In some embodiments, the first metal precursor is a hydrophobic Lewis acid. The hydrophobic metal reactant can comprise at least one hydrophobic hydrocarbon ligand, such as an alkyl, alkenyl, cyclic C3-C8, or aromatic group. In some embodiments, the first metal precursor can be bis(methylcyclopentadienyl)methoxymethylzirconium.

[0066] In some embodiments, the first metal precursor comprises a transition metal. In some embodiments, the first precursor does not contain a noble metal, such as Ru.

[0067] In some embodiments, the first metal precursor may comprise at least one alkyl ligand, such as a C1-C4 alkyl ligand. In some embodiments, the first metal precursor may comprise an organometallic or metal-organic compound. In some embodiments, the first metal precursor may comprise at least one cyclopentadienyl (Cp) ligand. In some embodiments, the first metal precursor may comprise a formamidine anion or an amidine anion compound. In some embodiments, the first metal precursor may comprise a β-diketonate anion compound. In some embodiments, the first metal precursor may comprise an alkylamino compound, such as a dialkylamino compound. In some embodiments, the first metal precursor may comprise an alkylamino ligand, such as -NMe2, -NEt2, or -NEtMe.

[0068] In some embodiments, the first metal precursor may comprise magnesium. In some embodiments, the first metal precursor may be an organometallic or metal-organic compound containing magnesium. For example, in some embodiments, the first metal precursor may comprise Mg(Cp)2 or a derivative thereof.

[0069] In some embodiments, the first metal precursor may comprise lanthanum. In some embodiments, the first metal precursor may be an organometallic compound containing lanthanum. In some embodiments, the first metal precursor may comprise lanthanum formamidine (La(FAMD)3).

[0070] In some embodiments, the first metal precursor may comprise hafnium. In some embodiments, the first metal precursor may comprise an organometallic compound containing hafnium. For example, in some embodiments, the first metal precursor may comprise an alkylamino hafnium compound, such as tetra(ethylmethylamino)hafnium (TEMAH, Hf(NEtMe)4) or a derivative thereof.

[0071] In some embodiments, the first metal precursor has the following formula:

[0072] MgL2 (I)

[0073] Wherein Mg is magnesium, and wherein each L can be independently selected as a hydrocarbyl group. In some embodiments, each L can be a linear, branched, cyclic alkyl or unsaturated hydrocarbyl group such as an alkenyl, alkynyl, aromatic, cyclopentadienyl, phenyl, cyclooctadienyl or cycloheptatrienyl group. In some embodiments, one or two of the Ls can be a cyclopentadienyl group. In some embodiments, one or two of the Ls can be a bidentate ligand such as a β-diketonate anion, a guanidinate anion or an amidinate anion. In some embodiments, the β-diketonate anion ligand can be an acetylacetonate anion or a 2,2,6,6-tetramethyl-3,5-heptanedionate anion ligand (THD).

[0074] In some embodiments, the first metal precursor is a cyclopentadienyl compound or a derivative thereof, such as an alkyl-substituted cyclopentadienyl compound and having the formula:

[0075] Mg(R 1 R 2 R 3 R 4 R 5 Cp)2 (II)

[0076] Wherein each of the R 1 groups, each of the R 2 groups, each of the R 3 groups, each of the R 4 groups and each of the R 5 groups can be independently selected as hydrogen or a substituted or unsubstituted alkyl group. In some embodiments, each of the R 1 groups, each of the R 2 groups, each of the R 3 groups, each of the R 4 groups and each of the R 5 groups can be independently selected as hydrogen or a linear or branched C1-C5 alkyl group. In some embodiments, each of the R 1 groups, each of the R 2 groups, each of the R 3 groups, each of the R 4 groups and each of the R 5 groups can be independently selected as hydrogen or a C1-C3 alkyl group such as a methyl, ethyl, n-propyl or isopropyl group. In some embodiments, the first precursor is Mg(Cp)2.

[0077] In some embodiments, the first metal precursor comprises one or more ligands such as a cyclopentadienyl (“Cp”) ligand. These first precursor compounds can be selected from the following compounds:

[0078] (Cp)x La(III);

[0079] (Cp) x L y La(IV);

[0080] (Cp) x W n La(V);

[0081] (CP) x L y W n La(VI);

[0082] La is lanthanum, Cp is a cyclopentadienyl or cyclooctadienyl group such that the Cp groups in Chemical Formulas I-IV can be the same as or different from each other; x represents the number of Cp ligands and it is an integer from 1 to the oxidation state of La; it should be noted that cyclooctadiene is usually abbreviated as Cod, but here the representation is simplified by using a single general abbreviation Cp for both cyclopentadienyl and cyclooctadienyl;

[0083] L y is a neutral adduct ligand that binds to the metal from one or more of its atoms and where y represents the number of ligands bound; and

[0084] W is some other ligand with a valence less than Cp and where n represents the number of ligands. In some embodiments, W is an amidine anion or a formamidine anion. In some embodiments, W is a β-diketonate anion or its corresponding sulfur or nitrogen compound, halide, amide, alkoxide, carboxylate, or Schiff base.

[0085] In Chemical Equations I-IV, the cyclopentadienyl and / or cyclooctadienyl groups can be in the same molecule such that there is a bridge between two Cp groups consisting of a substituted or unsubstituted C1-C6 chain that may contain heteroatoms selected from Si, N, P, Se, S, or B.

[0086] In some embodiments, L is independently selected from:

[0087] (i) hydrocarbons,

[0088] (ii) hydrocarbons containing oxygen,

[0089] (iii) hydrocarbons containing nitrogen,

[0090] (iv) hydrocarbons containing sulfur,

[0091] (v) hydrocarbons containing phosphorus,

[0092] (vi) hydrocarbons containing arsenic,

[0093] (vii) hydrocarbons containing selenium and / or

[0094] (viii) Hydrocarbons containing tellurium

[0095] In some embodiments, L is and independently selected from:

[0096] (a) An amine or polyamine,

[0097] (b) A bipyridine,

[0098] (c) A ligand according to the following chemical scheme:

[0099]

[0100] wherein G is -O-, -S- or -NR 1 , where R 1 is independently selected from hydrogen or a substituted or unsubstituted, cyclic, straight-chain or branched alkyl, alkenyl, aryl, alkylaryl, arylalkyl, alkoxy, thio, cyano or silyl group. The cyclic or aromatic rings in R 1 may contain heteroatoms. The hydrogen or R 1 -type substituents may also be attached to the carbon atoms in Chemical Equation V, or

[0101] (d) An ether or a thioether.

[0102] A cyclopentadienyl or cyclooctadienyl group, and Cp in Chemical Equations I-IV has the following form:

[0103] Cp′R m H a-m (VII)

[0104] wherein when a is 8, m is an integer from 0 to 8, and when a is 5, m is an integer from 0 to 5,

[0105] Cp′ is a fused or separated cyclopentadienyl or cyclooctadienyl, and

[0106] R is an independently selected hydrocarbon fragment containing 1-6 carbon atoms, such as a C1-C6 hydrocarbon.

[0107] In some embodiments, each R ligand may be the same as each other, or each R ligand may be different from each other. That is, each R ligand may be independently selected. In some embodiments, R may be a substituted or unsubstituted, cyclic, straight-chain or branched alkyl alkenyl, aryl, alkylaryl, arylalkyl, alkoxy, thio, amino, cyano or silyl group. The cyclic or aromatic rings of the substituents may contain heteroatoms. Examples of substituents are methyl, ethyl, propyl and isopropyl groups.

[0108] The neutral adduct ligand L shown in Chemical Formulas II and IV can be independently selected from ethers, amines, or solvent molecules such as tetrahydrofuran, which form a bond with the metal through one atom. Examples of suitable neutral adduct ligands that form a bond with the metal through several atoms are polyethers and polyamines.

[0109] In some embodiments, the first metal precursor can comprise at least one cyclopentadienyl ligand and can be written according to Formula VIII:

[0110] (R 1 R 2 R 3 R 4 R 5 Cp) x —MR 0 z —(R 6 ) y (VIII)

[0111] wherein M is a metal selected from Mg, Sr, Ba, Sc, Y, and the lanthanides;

[0112] wherein each of the R 0 groups, each of the R 1 groups, each of the R 2 groups, each of the R 3 groups, each of the R 4 groups, and each of the R 5 groups can be independently selected from:

[0113] i. hydrogen;

[0114] ii. independently substituted or unsubstituted straight-chain and branched C1-C6 alkyl, alkenyl, and alkynyl groups;

[0115] iii. carbocyclic groups such as aryl, phenyl, cyclopentadienyl, alkylaryl, and halocarbocyclic groups; and

[0116] iv. heterocyclic groups;

[0117] wherein R 6 is independently selected from:

[0118] i. hydrogen;

[0119] ii. independently substituted or unsubstituted straight-chain and branched C1-C6 alkyl, alkenyl, and alkynyl groups;

[0120] iii. carbocyclic groups such as aryl, phenyl, cyclopentadienyl, alkylaryl, and halocarbocyclic groups;

[0121] iv. heterocyclic groups; and

[0122] v. NR1 R 2 ; and

[0123] wherein both x and y are 1 and z is 0.

[0124] In some embodiments, the first metal precursor comprising a cyclopentadienyl compound comprises at least one ligand that is bonded to the metal via nitrogen, as depicted by Formula IX:

[0125] (R 1 R 2 R 3 R 4 R 5 Cp) x —MR 0 z —(NR 1 R 2 ) y (IX)

[0126] wherein M is a metal selected from Mg, Sr, Ba, Sc, Y, or the lanthanides;

[0127] wherein each of the R0 groups, each of the R1 groups, each of the R2 groups, each of the R3 groups, each of the R4 groups, and each of the R5 groups is independently selected from:

[0128] i. hydrogen;

[0129] ii. independently substituted or unsubstituted straight-chain and branched C1-C6 alkyl, alkenyl, and alkynyl groups;

[0130] iii. carbocyclic groups such as aryl, phenyl, cyclopentadienyl, alkylaryl, and halocarbocyclic groups; and

[0131] iv. heterocyclic groups; and

[0132] wherein both x and y are 1 and z is 0.

[0133] In Formula IX, the alkyl, alkenyl, and alkynyl groups can be selected from any straight-chain or branched alkyl, alkenyl, and alkynyl groups having 1 to 6 carbon atoms. Examples of such alkyl groups include methyl; ethyl; n-propyl and isopropyl; n-butyl, isobutyl, and tert-butyl; n-pentyl and isopentyl (amyl); n-pentyl and isopentyl (pentyl); n-hexyl and isohexyl; and 2,3-dimethyl-2-butyl. In some embodiments, alkyl groups are used. In other embodiments, C 1-6 alkenyl and alkynyl groups, including the corresponding groups with the appropriate unsaturation, can be used.

[0134] In some embodiments, the first metal precursor is a compound having at least one cyclopentadienyl ligand and at least one chelating ligand such as a bidentate ligand. In some embodiments, the compound is represented by Formula X: (R 1 R 2 R 3 R 4 R 5 Cp) x —MR 0 z —(NR 1 NR 2 R) y depicted as:

[0135]

[0136] wherein M is a metal selected from Mg, Sr, Ba, Sc, Y, or the lanthanides;

[0137] wherein R can be any straight-chain and branched C1-C6 alkyl, alkenyl, or alkynyl group, either substituted or unsubstituted, and R can be bonded to two bridging nitrogen atoms at any point in the alkyl, alkenyl, and alkynyl groups;

[0138] wherein each of the R 0 groups, each of the R 1 groups, each of the R 2 groups, each of the R 3 groups, each of the R 4 groups, and each of the R 5 groups can be independently selected from:

[0139] i. hydrogen;

[0140] ii. independently substituted or unsubstituted straight-chain and branched C1-C6 alkyl, alkenyl, and alkynyl groups;

[0141] iii. carbocyclic groups such as aryl, phenyl, cyclopentadienyl, alkylaryl, and halocarbocyclic groups; and

[0142] iv. heterocyclic groups; and

[0143] wherein both x and y are 1 and z is 0.

[0144] In some other embodiments, the first metal precursor can be represented by Formula XI: (R 1 R 2 R 3 R 4 R 5 Cp) x —MR 0 z —[(NR 1 NR2 ) CNR 3 y Depict:

[0145]

[0146] wherein M is a metal selected from Mg, Sr, Ba, Sc, Y or the lanthanides;

[0147] wherein each of the R 0 groups, each of the R 1 groups, each of the R 2 groups, each of the R 3 groups, each of the R 4 groups and each of the R 5 groups may be independently selected from

[0148] i. hydrogen;

[0149] ii. independently substituted or unsubstituted straight-chain and branched C1-C6 alkyl, alkenyl and alkynyl groups;

[0150] iii. carbocyclic groups such as aryl, phenyl, cyclopentadienyl, alkylaryl and halogenated carbocyclic groups; and

[0151] iv. heterocyclic groups; and

[0152] wherein both x and y are 1 and z is 0.

[0153] In a further embodiment, the first metal precursor is represented by formula XII: (R 1 R 2 R 3 R 4 R 5 Cp) x —MR 0 z —[(NR 1 NR 2 )CNR 3 R 4 y Depict:

[0154]

[0155] wherein M is a metal selected from Mg, Sr, Ba, Sc, Y or the lanthanides;

[0156] wherein each of the R 0 groups, each of the R 1 groups, each of the R 2 groups, each of the R 3 groups, each of the R 4 groups and each of the R​​5 Each of the groups may be independently selected from:

[0157] i. hydrogen;

[0158] ii. independently substituted or unsubstituted straight-chain and branched C1-C6 alkyl, alkenyl and alkynyl groups;

[0159] iii. carbocyclic groups such as aryl, phenyl, cyclopentadienyl, alkylaryl and halocarbocyclic groups; and

[0160] iv. heterocyclic groups; and

[0161] wherein both x and y are 1 and z is 0.

[0162] In some embodiments, the first metal precursor as described in Formulas VIII-XII may comprise R 0 , R 1 , R 2 , R 3 , R 4 , R 5 and R 6 , wherein each of the R 0 groups, each of the R 1 groups, each of the R 2 groups, each of the R 3 groups, each of the R 4 groups and each of the R 5 groups and each of the R 6 groups may be independently selected from

[0163] i. hydrogen;

[0164] ii. independently substituted or unsubstituted straight-chain and branched C1-C6 alkyl, alkenyl and alkynyl groups;

[0165] iii. carbocyclic groups such as aryl, phenyl, cyclopentadienyl and alkylaryl; and

[0166] iv. heterocyclic groups

[0167] Optionally, the first metal precursor as described may comprise a modified cyclopentadienyl group. In some embodiments, the modified cyclopentadienyl group is selected from Me5Cp, MeCp, EtCp and Me3SiCp. In further embodiments, the first metal precursor may comprise an anionic or dianionic guanidinate ligand such as a triisopropylguanidinate ligand.

[0168] In some embodiments, the second reactant comprises oxygen and may be referred to herein as an oxygen precursor, an oxygen reactant, an oxygen-containing precursor, or an oxygen-containing reactant. In some embodiments, the second reactant comprises molecular oxygen (O₂). In some embodiments, the second reactant does not comprise an oxygen-containing compound other than O₂. In some embodiments, the second reactant does not comprise O₃ or H₂O. In some embodiments, the second reactant does not comprise a plasma, such as an oxygen plasma. In some embodiments, the second reactant is supplied or mixed with an inert gas such as N₂, He, or Ar.

[0169] In some embodiments, the second reactant comprises molecular oxygen and less than about 50%, 25%, 15%, 10%, 5%, 1%, or 0.1% impurities other than inert gases.

[0170] In some embodiments, the selective catalyst deposition process can be carried out in situ, i.e., in the same reaction chamber as a previous passivation and / or a subsequent deposition process, such as a subsequent selective deposition of silicon oxide on a non-silylated surface relative to a silylated surface. However, in some embodiments, the selective catalyst deposition can be carried out in a reaction chamber separate from one or more subsequent processing steps, such as in a chamber that is part of a cluster tool.

[0171] In some embodiments, the substrate, particularly the metal surface, can be pretreated or cleaned before or at the beginning of the selective catalyst deposition.

[0172] Selective deposition of silica on a catalyzed metal surface relative to a dielectric surface

[0173] After passivation of the dielectric surface (if performed) and selective deposition of the catalyst on the metal surface (if performed), silicon oxide can be selectively deposited on the metal surface of the substrate relative to the dielectric surface. In some embodiments, silicon oxide is selectively deposited on the metal surface by contacting the substrate with a silicon reactant such as silanol (see, for example Figure 2D ). In some embodiments, the substrate surface is contacted with a silicon reactant and an oxygen reactant such as H₂O. The formation of silicon oxide is catalyzed by the presence of a catalyst on the metal surface or, in the absence of a catalyst, by the metal surface itself.

[0174] One or more silanols can be used as the silicon reactant, such as alkoxysilanols or alkoxysilanediols. In some embodiments, the silicon reactant can comprise one or more tris(tert-alkoxy) silanols, di(alkoxy)alkylsilanols, di(alkoxy)silanediols or bis(tert-alkoxy)silanediols. In some embodiments, the silanol can be selected from one or more of tris(tert-butoxy) silanol (TBS), tris(isopropoxy) silanol (TIS), and tris(tert-pentyloxy) silanol (TPS). A silanol is a compound that contains silicon bonded to one or more hydroxyl (OH) groups. In some embodiments, the silanol contains more than one OH-group directly bonded to the silicon atom. Silanol compounds include, but are not limited to, alkoxysilanols, alkoxyalkylsilanols, and alkoxysilanediols. In some embodiments, the silicon precursor comprises TPS. In some embodiments, the silicon source is di(alkoxy)silanediol.

[0175] In some embodiments, only a single silanol pulse is provided after the catalyst has been deposited on the metal surface. In some embodiments, a single silanol pulse is used to deposit a silica film having a thickness greater than 5 angstroms as measured on the top surface of the metal surface on the substrate. As described above, in some embodiments, the substrate can be contacted with the catalyst and the silanol in one or more silicon oxide deposition sub-cycles. The sub-cycles can be repeated until a silicon oxide film of the desired thickness has been selectively formed above the metal surface. In some embodiments, a single sub-cycle can be all that is required to obtain the desired thickness of the silica film. In other embodiments, the steps can be repeated 2, 3, 4, 5, 6, 7, 8, 9, 10 times or more.

[0176] In some embodiments, more than one silanol pulse is provided in each deposition super-cycle. For example, two, three or more silanol pulses can follow the catalyst pulse. In some embodiments, two silanol pulses follow the catalyst pulse. Each silanol pulse can be separated by a purge step. In other embodiments, each silanol pulse is provided after a predetermined time delay without an intermediate purge step.

[0177] Although typically described as starting with the provision of the catalyst, each silicon oxide deposition sub-cycle can start with either reactant. However, as will be recognized by those skilled in the art, if the first sub-cycle starts with the silanol reactant, deposition may not begin until the second deposition super-cycle.

[0178] Regarding the catalyst, surface saturation will ensure that the catalyst occupies all available reaction sites (e.g., limited by physical size or "steric hindrance") and thus ensure excellent step coverage. However, in some embodiments, the catalyst may be provided in a non-saturated or under-saturated dosage. For example, in a deep trench structure, it is important to form a "collar", which is an etch stop layer that must extend only along a portion of the trench. In this example, an under-saturated pulse of the catalyst can be used to preferentially deposit the catalyst along the collar region compared to the surface deeper in the trench. Thus, silica deposition occurs only at the depth reached by the catalyst and thus the extent of silica deposition is limited to the desired depth. Accordingly, in some embodiments, the dosage of the catalyst is metered to provide a predetermined amount of catalyst and a predetermined amount of silica deposition.

[0179] Regarding the silanol reactant, in some embodiments, a saturated pulse of silanol is provided. However, since the growth rate of silica depends in part on the diffusion of the precursor through the growing film, the growth rate can be controlled, for example, by controlling the precursor dosage, purge time, and / or temperature. Accordingly, in some embodiments, a non-saturated dosage of silanol can be provided. In some embodiments, the dosage and / or exposure time of the silanol reactant can be limited to provide a specific thickness and / or specific depth of silica in a given reaction cycle.

[0180] In some embodiments, a silica thin film is selectively formed on a metal surface of a substrate relative to a dielectric surface by selecting a catalyst capable of reacting with the metal surface and performing a deposition process including one or more silica deposition sub-cycles, where each silica deposition sub-cycle includes:

[0181] Providing a first gas-phase reactant pulse containing a metal catalyst to form a catalyst of no more than about a single molecular layer on the metal surface of the substrate;

[0182] Removing excess catalyst from the reaction chamber;

[0183] Providing a second gas-phase reactant pulse containing silanol to the reaction chamber; and

[0184] Removing excess second reactant and reaction by-products (if any) from the reaction chamber.

[0185] In some embodiments, a silica thin film 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 dielectric surfaces.

[0186] The thickness of the film can be adjusted according to specific circumstances. In some embodiments, a silica thin film is deposited in the range of a few angstroms to a few nanometers. In some embodiments, a silica thin film with a thickness of less than about 2 nm is deposited. In some embodiments, a silica thin film with a thickness of less than about 3 nm is deposited. In some embodiments, one or both of the catalyst and the silanol should be underdosed to achieve deposition of a film with a thickness of less than about 2 nm or less than about 3 nm. The thin film can be deposited in one deposition supercycle or multiple deposition supercycles.

[0187] Before starting to deposit the film, the substrate is usually heated to a suitable growth temperature. In some embodiments, the growth temperature of the silica thin film is lower than about 500 °C, lower than about 400 °C, lower than about 300 °C, lower than about 200 °C, lower than about 150 °C, or even lower than about 125 °C. The temperature is typically selected such that the catalyst does not decompose. In some embodiments, the deposition process can be carried out at a temperature higher than about 100 °C, for example, using TMA as the catalyst.

[0188] In some embodiments, the pulse time of the reactants can be from about 0.1 to about 10 seconds, and the purge time between reactant pulses can also be from about 0.1 to about 10 seconds.

[0189] The pressure in the reaction chamber is typically from about 0.1 mTorr to about 5 Torr, more preferably from about 0.1 mTorr to about 3 Torr, and most preferably from about 0.2 mTorr to about 3 Torr. However, in some cases, the pressure will be higher or lower than this range, which can be readily determined by those skilled in the art.

[0190] In one embodiment, in the silicon oxide deposition subcycle, silicon oxide such as silicon dioxide (e.g., SiO2) is deposited on the metal surface of the substrate relative to the passivated dielectric surface at a temperature of about 150 °C. TMA is pulsed into the reaction chamber for 150 ms, followed by a 3 s purge. Then TPS is pulsed into the reaction chamber for 100 s, followed by a 90 s purge.

[0191] Post-deposition treatment

[0192] After the selective deposition of the metal oxide, the substrate can be subjected to a post-deposition cleaning step as described above to remove the passivation layer from the oxide surface (see, for example Figure 2E ). In some embodiments, the cleaning step can include H2 plasma treatment. In some embodiments, the cleaning step is carried out at a temperature from about room temperature to about 400 °C. In some embodiments, a plasma power of about 25 to about 250 W can be used to generate a plasma in flowing H2, for example, at a flow rate of about 10 to about 500 sccm. In some embodiments, the cleaning time after depositing the metal oxide layer can be, for example, from about 0.1 to about 600 seconds or more.

[0193] In some embodiments, a silicon oxide film is deposited selectively on a metal or metallic surface of a three-dimensional structure relative to one or more passivated dielectric surfaces. The three-dimensional structure can include, for example, vias or trenches. In some embodiments, the dielectric surface can be selectively passivated and an aluminum catalyst can be deposited on the metal surface prior to depositing the silicon oxide film.

[0194] Passivation blocking layer

[0195] The passivation blocking layer can facilitate the selective formation of the passivation layer on the dielectric material relative to the passivation blocking layer. As described above, in some embodiments, a self-assembled monolayer (SAM) can be used to inhibit the silylation of the metal or metallic surface, thereby facilitating the selective passivation of the dielectric surface. In some embodiments, a non-SAM passivation blocking layer is used. The term "blocking" is thus merely a label and does not necessarily imply 100% passivation of the passivation layer deposition. As described elsewhere herein, even imperfect selectivity is sufficient, for example, to obtain a fully selective structure after an etch-back process.

[0196] Selectivity

[0197] The selective passivation and / or selective deposition can be fully selective or partially selective. Post-deposition etching can be performed after a partially selective process, which removes all of the deposited material above one surface but not all of the deposited material above a second surface, thereby forming a fully selective layer. Thus, in some embodiments, the selective deposition does not have to be fully selective in order to obtain the desired benefits.

[0198] The selectivity of deposition (or passivation) on a first surface herein referred to as surface A relative to a second surface herein referred to as surface B can be given by the percentage calculated as [(deposition on surface A) - (deposition on surface B)] / (deposition on surface A). The deposition can be measured in any of a variety of ways. For example, the deposition can be given by the measured thickness of the deposited material or by the measured amount of material deposited. In the embodiments described herein, an oxide surface (A) can be selectively passivated relative to a metal or metallic surface (B). With respect to passivation, if the passivation is caused by treating the substrate surface rather than depositing a layer, the amount of passivation can be a measure of the available reaction sites on the substrate surface that have reacted with the passivating agent. Subsequently, a metal oxide layer is deposited selectively on the metal or metallic surface (B) relative to the passivation layer above the oxide surface (A).

[0199] In some embodiments, the selectivity of selectively forming a passivation layer on a dielectric surface (relative to 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%.

[0200] In some embodiments, the selectivity of depositing a catalyst on a metal or metallic surface relative to a passivated dielectric 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%.

[0201] In some embodiments, the selectivity of depositing a catalyst on a metal or metallic surface relative to an unpassivated dielectric 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%.

[0202] In some embodiments, the selectivity of depositing silica on a catalyzed metal or metallic surface (relative to a passivated or unpassivated dielectric 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%.

[0203] In some embodiments, deposition occurs only on one surface and not on the other surface.

[0204] In some embodiments, the passivation of the dielectric surface by silylation is at least about 80% selective relative to the metal or metallic surface of the substrate. In some embodiments, the passivation process is at least about 50% selective. In some embodiments, the passivation process is at least about 10% selective. One of ordinary skill in the art will appreciate that a partially selective process can result in complete selective passivation of the oxide surface by post-deposition etching to remove any silylation from other surfaces.

[0205] In some embodiments, the deposition of the catalyst on the metal surface is at least about 80% selective relative to the passivated dielectric surface of the substrate. In some embodiments, the catalyst deposition process is at least about 50% selective. In some embodiments, the catalyst deposition process is at least about 10% selective. One of ordinary skill in the art will appreciate that a partially selective process can result in complete selective deposition on the metal surface by post-deposition etching to remove any catalyst from the dielectric surface.

[0206] In some embodiments, the deposition of silica on the catalyzed metal or metallic surface of a substrate is at least about 80% selective with respect to the silylated oxide surface of the substrate. In some embodiments, the deposition of silica on the catalyzed metal or metallic surface of a substrate is at least about 50% selective with respect to the silylated oxide surface of the substrate. In some embodiments, the deposition of silica on the catalyzed metal or metallic surface of a substrate is at least about 10% selective with respect to the silylated oxide surface of the substrate. Those skilled in the art will understand that post-deposition etching (or other processing) can be performed after a partially selective process, which will substantially remove all deposited material above the silylated dielectric surface. In addition, post-deposition processing can also help to customize the location and / or profile of the selectively deposited layer.

[0207] Selective deposition of silica on a metal or metallic surface

[0208] Figures 2A - 2E An embodiment is schematically shown of selectively passivating a first dielectric surface with respect to a second metal or metallic surface and then selectively depositing silica on the second metal or metallic surface with respect to the passivated first oxide surface.

[0209] Figure 2A A substrate is illustrated having exposed substantially different surfaces. For example, the first surface can comprise or be bounded by a dielectric material 220, such as a silica-based layer or a silicon surface having a native oxide formed thereon. The second surface can comprise or be bounded by a metal 210, such as copper (Cu).

[0210] Figure 2B The substrate is shown after selective passivation of the dielectric surface, such as by silylation. Figure 2A For example, a passivation layer 230 can be selectively formed on the dielectric surface 220 by exposing the substrate to 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).

[0211] Figure 2C The substrate is shown after selectively depositing an aluminum catalyst 240 on the metal surface 210 with respect to the passivation layer 230 on the dielectric surface 220. Figure 2BSubstrate. Aluminum catalyst 240 can be selectively formed on metal surface 210 by exposing the substrate to an aluminum reactant such as trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), dimethylaluminum isopropoxide (DMAI), tris(tert-butyl)aluminum (TTBA), tris(isopropanol)aluminum (TIPA), or triethylaluminum (TEA). Although an aluminum catalyst is illustrated, in other embodiments, a metal catalyst comprising other metals or other catalysts can be used as described herein.

[0212] Figure 2D shows the substrate after selective deposition of silica 250 on the catalyzed metal surface 210 relative to the dielectric surface 220 Figure 2C Substrate. In some embodiments, silica 250 is formed by exposing the substrate to a silanol reactant such as tris(tert-pentyloxy)silanol. The silanol reactant can decompose on the aluminum atoms on the catalyzed metal surface, resulting in the deposition of silica on the metal surface.

[0213] As described above, any silica deposited on a dielectric layer such as a passivated dielectric layer can be removed by a post-deposition treatment such as an etchback process. This etchback process can also remove silylation from the dielectric surface. Since silica is selectively deposited on the metal surface, any silica left on the passivated surface will be thinner than the silica formed on the metal surface. Thus, the post-deposition treatment can be controlled to remove all of the silica above the dielectric surface without removing all of the silica above the metal surface. Repeating the selective deposition and etchback in this manner can result in an increase in the thickness of the silica on the metal surface in each deposition and etch cycle. Repeating the selective deposition and etchback in this manner can also result in an overall increase in the selectivity of silica on the metal or metallic surface, since each deposition and etch cycle leaves a clean passivated layer on which selective silica deposition nucleates poorly. In other embodiments, the silica above the dielectric surface can be removed during a subsequent removal of the passivated layer. For example, a direct etch or lift-off method can be used to remove the silica from the passivated layer surface in the cyclic selective deposition and removal.

[0214] Figure 2E shows the substrate after a post-deposition treatment to remove the passivated layer 230 from the dielectric surface 220 by an etch process Figure 2DSubstrate. In some embodiments, the etching process may include exposing the substrate to a plasma. In some embodiments, the plasma may comprise oxygen atoms, oxygen radicals, oxygen plasma, or a combination thereof. In some embodiments, the plasma may comprise hydrogen atoms, hydrogen radicals, hydrogen plasma, or a combination thereof. In some embodiments, the plasma may comprise an inert gas species, such as an Ar or He species. In some embodiments, the plasma may consist essentially of an inert gas species. In some cases, the plasma may contain other substances, such as nitrogen atoms, nitrogen radicals, nitrogen plasma, or a combination thereof. In some embodiments, the etching process may include exposing the substrate to an etchant containing oxygen, such as O3. In some embodiments, the substrate may 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 may be supplied in a continuous pulse or in multiple pulses. As described above, the removal of the passivation layer can be used in the cyclic selective deposition and removal to strip any remaining metal oxides from above the oxide layer either by complete removal of the passivation layer or by partial removal of the passivation layer.

[0215] Additional processing, such as heat treatment or chemical treatment, may be performed before, after, or between the foregoing processes. For example, the treatment may modify 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 may be pretreated or cleaned before or at the start of the process. In some embodiments, the substrate may be subjected to a plasma cleaning process as described above.

[0216] Although 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 their obvious variations and equivalents.

Claims

1. A method for selectively depositing silicon oxide on a metal surface of a substrate relative to a dielectric surface of the substrate, the method sequentially comprising: contacting the substrate with a passivating agent; contacting the substrate with a metal catalyst; and contacting the substrate with a silicon reactant.

2. The method according to claim 1, wherein the metal catalyst comprises trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), dimethylaluminum isopropoxide (DMAI), tris(tert-butyl)aluminum (TTBA), tris(isopropanol)aluminum (TIPA), or triethylaluminum (TEA).

3. The method according to claim 1, wherein the silicon reactant comprises tris(tert-butoxy)silanol (TBS), tris(isopropoxy)silanol (TIS), or tris(tert-pentyloxy)silanol (TPS).

4. The method according to claim 1, wherein The metal catalyst includes an aluminum catalyst.

5. The method according to claim 4, wherein The aluminum catalyst includes aluminum isopropoxide.

6. The method according to claim 5, wherein, The aluminum catalyst includes dimethylaluminum isopropoxide (DMAI).

7. The method according to claim 6, wherein, The silicon reactant includes silanol.

8. The method according to claim 4, wherein The aluminum catalyst includes an organometallic compound.

9. The method according to claim 4, wherein The aluminum catalyst includes a heteroleptic aluminum compound.

10. The method according to claim 9, wherein, The heteroleptic aluminum compound contains an alkyl group and a halide.

11. The method according to claim 4, wherein The aluminum catalyst contains an alkyl precursor that contains two different alkyl groups as ligands.

12. The method according to claim 1, wherein The silicon reactant includes silanol.

13. A method for selectively depositing silicon oxide on a metal surface of a substrate relative to a dielectric surface of the substrate, comprising a deposition supercycle that includes: contacting the substrate with a silylating agent; and performing one or more silicon oxide deposition subcycles that include alternately and sequentially contacting the substrate with a metal catalyst and a silicon reactant.

14. The method according to claim 13, wherein the metal catalyst comprises trimethylaluminum (TMA), dimethylaluminum chloride, aluminum trichloride (AlCl3), dimethylaluminum isopropoxide (DMAI), tris(tert-butyl)aluminum (TTBA), tris(isopropanol)aluminum (TIPA), or triethylaluminum (TEA).

15. The method according to claim 13, wherein, The metal catalyst includes an aluminum catalyst.

16. The method according to claim 15, wherein, The aluminum catalyst includes aluminum isopropoxide.

17. The method according to claim 15, wherein, The aluminum catalyst includes dimethylaluminum isopropoxide (DMAI).

18. The method according to claim 17, wherein, The silicon reactant includes silanol.

19. The method according to claim 15, wherein, The aluminum catalyst includes an organometallic compound.

20. The method according to claim 13, wherein, The silicon reactant includes silanol.

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