Metal chloride precursors and deposition of metal-containing films

Abstract

A method for forming a metal-containing film comprises: a) exposing a substrate to a vapor of a metal-containing film-forming composition; b) exposing the substrate to a co-reactant; and c) repeating the steps of a) and b) until a desired thickness of the metal- containing film is deposited on the substrate using an ALD process. The metal- containing film-forming composition comprises a metal chloride precursor M(R1R2R3R4R5Cp)xCly, preferably selected from Hf(sPentylCp)Cl3 or Zr(sPentylCp)Cl3. A deposition temperature is preferably higher than 400°C.

Description

METAL CHLORIDE PRECURSORS AND DEPOSITION OF METAL-CONTAINING FILMSTechnical Field

[0001] The present invention relates to metal-containing film-forming compositions comprising metal chloride precursors, methods of synthesizing the metal chloride precursors, and methods of forming metal containing films via vapor deposition processes using the metal-containing film-forming compositions. In particular, relates to the metal chloride precursors, such as Hf(sPentylCp)Cb and Zr(sPentylCp)Cl3, which have low melting point with a good ALD process performance in a temperature higher than 400°C.Background

[0002] The scaling of next-generation memory, including 3D NAND and DRAM, necessitates the use of high-K dielectric films, with HfO2 being critical for chargetrapping layers and capacitor dielectrics. High-temperature Atomic Layer Deposition (ALD) (>400°C) of high quality crystalline HfCh films is thus a critical process in the fabrication of advanced memory devices.

[0003] Elevated deposition temperatures are essential for driving complete precursor reactions, resulting in films with high purity (low carbon, hydrogen and nitrogen content) and maximal density, which minimizes leakage current and enhances reliability. Moreover, high-temperature ALD is key to controlling the crystal structure: it facilitates the formation of the desired crystal phase, ensuring the required dielectric properties for conventional DRAM capacitor and 3D NAND charge trap cell operation. For instance, monoclinic and cubic phase are generally favored at increased temperature, which is beneficial for the Hafnium oxide dielectric constant.

[0004] Furthermore, this process is essential to achieve the ferroelectric orthorhombic phase of HfCh in emerging ferroelectric field-effect transistor (FeFET) memory, ensuring sufficient charge storage and a wide memory window necessary for advanced non-volatile applications.

[0005] Ferroelectrics have been widely investigated for their potential in various applications, including infrared detection, piezoelectric sensing, and microwaveelectronics, but particularly as the basis for ferroelectric random access memory (FeRAM). FeRAM devices offer compelling advantages over conventional memory technologies, notably high speed, low power consumption, and enhanced reliability. Despite these benefits, the commercial development of FeRAM has been constrained, as conventional ferroelectric thin films, such as PZT and SBT, suffer from ferroelectricity degradation when scaled below approximately 70 nm. Furthermore, the incorporation of materials like lead and bismuth creates incompatibility issues with standard complementary metal-oxide-sem iconductor (CMOS) fabrication processes, limiting manufacturing to the 130 nm technology node. An alternative, the Ferroelectric Field-Effect Transistor (FeFET), is similarly limited by the intrinsic properties of perovskite materials, where a small coercive field and high permittivity result in poor data retention. There is therefore a critical and unmet need in the art for a new class of ferroelectric materials and processes that are both CMOS-compatible and highly scalable. To this end, the development of novel ferroelectric HfO2 deposition processes is necessary to enable the next generation of high-performance FeRAM and FeFET devices.

[0006] Hafnium Nitride (HfN) is an essential material in advanced 3D NAND and DRAM fabrication, primarily serving as a conductive metal electrode (e.g., wordlines, charge-trapping layers) and a robust diffusion barrier.

[0007] The use of high-temperature Atomic Layer Deposition (ALD) (>400°C) is crucial for depositing high-quality HfN films conformally over the extreme aspect ratio (AR) structures common to these devices. Elevated deposition temperatures are necessary to maximize purity and density by ensuring the complete reaction and efficient removal of precursor byproducts, resulting in low-resistivity films with reduced carbon and oxygen contamination. This low-resistance property is vital for its function as an electrode in high-density stacks. Moreover, high temperature promotes the formation of the desired crystalline phase, which provides superior thermal stability, mechanical strength, and etch resistance. This robustness is critical for HfN to act as an effective barrier layer against metal diffusion (e.g., tungsten precursors) and to withstand subsequent harsh thermal and plasma processing steps inherent in 3D stacking. Finally, high process temperature ensures uniformity in high-AR trenches by maintaining the self-limiting nature of the ALD process deep within 3D channels, guaranteeing near 100% step coverage and uniform film thickness across the entire device architecture. Furthermore, 400°C and above isgenerally considered the temperature at which NH3 provides proper reactivity. Precursors having sufficient thermal stability with self-limited ALD behavior above 400°C thus allow to use NH3 as co-reactant to grow high quality nitride films with low Carbon and low Chlorine content.

[0008] Recently, HfC>2 film is considered for a wide range of applications (such as gate dielectric and gap filling) utilizing deposition progress with HfCU as a precursor. However, HfCU has some drawback such as high chlorine impurity level, particle and storage issues due to its high melting point, and low vapor pressure. Attempts of forming HfC>2 and HfN using chlorinated hafnium or other metal precursors have been disclosed. Hf precursors that have a low chlorine impurity level, a low melting point and may deposit at a high temperature such as higher than 400°C are required.

[0009] US 2007 / 0259111A1 to Singh et al. discloses forming hafnium oxide films using chlorinated hafnium precursors such as Hf(‘BuCp)2Cl2, HfCp2Ch, Hf(EtCp)2Cl2, Hf(MeCp)2CI2, Hf(Me5Cp)CI3, Hf(iPrCp)2CI2and HfCPrOpJC .

[0010] JP2005209766A discloses the use of HfCpCh for deposition of Hf- containing films by MOCVD.

[0011] KR100804413B1 discloses the synthesis method or ZrCpCh as a precursor for deposition methods.

[0012] J. Mater. Chem. C, 2023, 11 , 8018-8026 discloses deposition of HfN using TEMAHf and NH3.

[0013] Journal of the Korean Physical Society, Vol. 56, No. 3, March 2010, pp. 905-910 discloses deposition of HfN using TDMAHf and N2 plasma.

[0014] Electrochem. Solid State 9, C123 (2006) discloses deposition of HfN using TDMAHf with N2+H2 plasma.

[0015] J. Vac. Sci. Technol. A 35(1 ), Jan / Feb 2017 discloses deposition of HfN using either N2 or H2 plasma.Summary

[0016] Disclosed is a method for forming a metal-containing film, the method comprising the steps of: a) exposing a substrate to a vapor of a metal-containing film-forming composition; b) exposing the substrate to a co-reactant; andc) repeating the steps of a) and b) until a desired thickness of the metalcontaining film is deposited on the substrate using a vapor deposition process, wherein the metal-containing film-forming composition comprises a metal chloride precursor having the formula:M(R1R2R3R4R5Cp)xClywherein, M is Hf or Zr; R1, R2, R3, R4and R5each are independently selected from a hydrogen atom, a Ci to C10 linear or branched alkyl-group, a C3 to C10 cyclic alkyl- group, or F, Si, Ge containing Ci to C10 linear and branched alkyl chain, provided that at least one of the R1, R2, R3, R4and R5is selected from a C5 to C10 linear or branched alkyl-group; x and y are integers; provided thatx+y equals to 4. The disclosed methods may include one or more of the following aspects:• further comprising the step of: introducing an inert gas purge following the steps a) and b), respectively, to separate each exposure, wherein the inert gas purge uses an inert gas selected from N2, He, Ar, Kr, orXe;• a deposition temperature being higher than 400°C;• x equaling to 1 , y equaling to 3;• the metal chloride precursor being M(sPentylCp)Cb, wherein M is Hf or Zr;• the metal chloride precursor being Hf(sPentylCp)Cl3;• the metal chloride precursor being Zr(sPentylCp)Cl3;• R1to R5each being independently selected from H, Me, Et,nPr, 'Pr,sPr, ‘Bu, sBu, 'Bu,nBu, ‘Amyl, sec-pentyl, SiMes, SiMe2H, or SiH2Me.• the co-reactant being selected from the group consisting of O2, O3, H2O, H2O2, NO, N2O, NO2, oxygen containing radicals selected from O- OH-, carboxylic acids, formic acid, acetic acid, propionic acid, and mixtures thereof;• the co-reactant is O3;• the co-reactant being selected from the group consisting of H2, H2CO, N2,NH3, N2H2, N2H4, N2O, a primary amine, a secondary amine, a tertiary amine, trisilylamine, a hydrazine selected from Me2NNH2, MeHNNMeH, tBuHNNH2, N(SiHs)3, B2H6, Si2He, radicals thereof, and mixtures thereof;• the co-reactant being NH3;• the metal-containing film being an HfO2, HfN, ZrO2 or ZrN film; and• the vapor deposition process being a PEALD process.

[0017] Also disclosed is a method of depositing an MO2 or MN film or coating the MO2 or MN film on a substrate, the method comprising the steps of: a) exposing the substrate to a vapor of M(sPentylCp)Cl3; b) exposing the substrate to a co-reactant; c) repeating the steps of a) and b) until a desired thickness of the MO2 or MN film is formed on the substrate using an ALD process, wherein M is Hf or Zr. The disclosed methods may include one or more of the following aspects:• further comprising the step of: introducing an inert gas purge following the steps a) and b), respectively, to separate each exposure, wherein the inert gas purge uses an inert gas selected from N2, He, Ar, Kr, or Xe;• a deposition temperature being higher than 400°C;• the co-reactant is selected from the group consisting of O2, O3, H2O, H2O2,NO, N2O, NO2, oxygen containing radicals selected from O- OH-, carboxylic acids, formic acid, acetic acid, propionic acid, and mixtures thereof;• the co-reactant is selected from the group consisting of H2, H2CO, N2, NH3, N2H2, N2H4, N2O, a primary amine, a secondary amine, a tertiary amine, trisilylamine, a hydrazine selected from Me2NNH2, MeHNNMeH, tBuHNNH2, N(SiHs)3, B2H6, Si2Hs, radicals thereof, and mixtures thereof; and• the ALD process being a PEALD.

[0018] Also disclosed is a metal-containing film-forming composition for a vapor deposition process comprising a precursor having the formula:M(R1R2R3R4R5Cp)xClywherein, M is Hf or Zr; R1, R2, R3, R4and R5each are independently selected from a hydrogen atom, a Ci to C10 linear or branched alkyl-group, a C3 to C10 cyclic alkyl- group, or F, Si, Ge containing Ci to C10 linear and branched alkyl chain, provided that at least one of the R1, R2, R3, R4and R5is selected from a C5 to C10 linear or branched alkyl-group; x and y are integers; provided that x+y equals to 4. The disclosed methods may include one or more of the following aspects:• R1to R5each being independently selected from H, Me, Et,nPr, 'Pr,sPr, ‘Bu, sBu, 'Bu,nBu, ‘Amyl, sec-pentyl, SiMes, SiMe2H, or SiH2Me;• x equals to 1 , y equals to 3;• the precursor being selected from the group consisting of Hf(sPentylCp)Cl3 and Zr(sPentylCp)Cl3.

[0019] Also disclosed is a composition comprising a precursor selected from the group consisting of Hf(sPentylCp)Cls and Zr(sPentylCp)Cl3 The disclosed methods may include one or more of the following aspects:• the precursor being Hf(sPentylCp)C;and• the precursor being Zr(sPentylCp)Cl3.

[0020] Also disclosed is a method of providing a vapor of a liquid precursor Hf(sPentylCp)Cl3 or Zr(sPentylCp)Cl3 to a processing equipment, the method comprising the steps of:A. pressurizing a vessel containing the liquid precursor Hf(sPentylCp)Cl3 or Zr(sPentylCp)Cl3 with an inert gas selected from He, Ar, N2 or mixtures thereof, while keeping the temperature of the vessel and a delivery line from the vessel to the processing equipment above the melting point of the precursor;B. feeding the liquid precursor Hf(sPentylCp)Cl3 or Zr(sPentylCp)Cl3 directly into the processing equipment via the delivery line, by direct liquid injection or vaporization;C. alternatively, via the delivery line, refilling the liquid precursor Hf(sPentylCp)Cl3 or Zr(sPentylCp)Cl3 to a bubbler mounted in the processing equipment with and keeping the liquid in the bubbler at a temperature necessary to provide sufficient vapor to the process equipment. The disclosed methods may include one or more of the following aspects:• the vessel and the delivery line to the processing equipment being kept at a temperature that provides a viscosity of the precursor of less than 30 cP; and• the vessel and the delivery line to the processing equipment being kept at a temperature that provides a viscosity of the precursor of less than 10 cP.Notation and Nomenclature

[0021] The following detailed description and claims utilize a number of abbreviations, symbols, and terms, which are generally well known in the art.

[0022] As used herein, the indefinite article “a” or “an” means one or more.

[0023] As used herein, “about” or “around” or “approximately” in the text or in a claim means ±10% of the value stated.

[0024] As used herein, “room temperature” in the text or in a claim means from approximately 20°C to approximately 30°C.

[0025] The term “ambient temperature” refers to an environment temperature approximately 20°C to approximately 30°C.

[0026] The term “substrate” refers to a material or materials on which a process is conducted. The substrate may refer to a wafer having a material or materials on which a process is conducted. The substrates may be any suitable wafer used in semiconductor, photovoltaic, flat panel, or LCD-TFT device manufacturing. The substrate may also have one or more layers of differing materials already deposited upon it from a previous manufacturing step. For example, the wafers may include silicon layers (e.g., crystalline, amorphous, porous, etc.), silicon containing layers (e.g., SiC>2, SiN, SiON, SiCOH, etc.), metal containing layers (e.g., copper, cobalt, ruthenium, tungsten, platinum, palladium, nickel, ruthenium, gold, etc.) or combinations thereof. Furthermore, the substrate may be planar or patterned. The substrate may be an organic patterned photoresist film. The substrate may include layers of oxides which are used as dielectric materials in MEMS, 3D NAND, MIM, DRAM, or FeRam device applications (for example, ZrC>2 based materials, HfO2 based materials, TiO2 based materials, AI2O3 based materials, rare earth oxide based materials, ternary oxide based materials, etc.) or nitride-based films (forexample, TaN, TiN, NbN) that are used as electrodes. One of ordinary skill in the art will recognize that the terms “film” or “layer” used herein refer to a thickness of some material laid on or spread over a surface and that the surface may be a trench or a line. Throughout the specification and claims, the wafer and any associated layers thereon are referred to as substrates.

[0027] The term “wafer” or “patterned wafer” refers to a wafer having a stack of films on a substrate and at least the top-most film having topographic features that have been created in steps prior to the deposition of the metal-containing film.

[0028] Note that herein, the terms “substrate”, “wafer” and “workpiece” may be used interchangeably. It is understood that a substrate may correspond to or related to a wafer or a workpiece, and that the wafer or workpiece may refer to the substrate.

[0029] The term “aspect ratio” refers to a ratio of the height of a trench (or aperture)to the width of the trench (or the diameter of the aperture).

[0030] The term “high aspect ratio” refers to an aspect ratio larger than approximately 2:1 , preferably an aspect ratio ranging from approximately 2:1 to approximately 200:1 .

[0031] Note that herein, the terms “film” and “layer” may be used interchangeably. It is understood that a film may correspond to, or related to a layer, and that the layer may refer to the film. Furthermore, one of ordinary skill in the art will recognize that the terms “film” or “layer” used herein refer to a thickness of some material laid on or spread over a surface and that the surface may range from as large as the entire wafer to as small as a trench or a line.

[0032] Note that herein, the terms “aperture”, “via”, “hole” and “trench” may be used interchangeably to refer to an opening formed in a semiconductor structure.

[0033] As used herein, the abbreviation "NAND" refers to a "Negative AND" or "Not AND" (electronic logic gate); the abbreviation "2D" refers to 2 dimensional gate structures on a planar substrate; the abbreviation "3D" refers to 3 dimensional or vertical gate structures, wherein the gate structures are stacked in the vertical direction.

[0034] Note that herein, the terms “deposition temperature” and “substrate temperature” may be used interchangeably. It is understood that a substrate temperature may correspond to, or be related to a deposition temperature, and that the deposition temperature may refer to the substrate temperature.

[0035] The term “film-forming composition” refers to a composition used for deposition of a film. The film-forming composition may include, but is not limited to, a precursor, a solvent and / or a carrier gas. Furthermore, the film-forming composition may include, but is not limited to, a precursor, optionally a solvent, optionally a carrier gas, and optionally one or more co-reactant(s). Herein, the precursor may be supplied either in a neat form or in a blend with a suitable solvent. The precursor may be present in varying concentrations in the solvent. Alternatively, the precursor may be vaporized by passing a carrier gas into a container that contains the precursor or by bubbling the carrier gas into the precursor. The carrier gas and precursor are then introduced into a reactor as a vapor. The co-reactant may be an oxidizer, a reducing agent, a dilute gas, an additive, an inhibitor, an additional or a secondary precursor, etc., for assisting in formation of the film. Here, the oxidizer may be selected from the group consisting of O2, O3, H2O, H2O2, NO, N2O, NO2, oxygen containing radicals such as O- OH-,carboxylic acids, formic acid, acetic acid, propionic acid, and mixtures thereof. Preferably, the oxidizer is O3. The reducing agent may be selected from the group consisting of H2, H2CO, N2, NH3, N2H2, N2H4, N2O, a primary amine, a secondary amine, a tertiary amine, trisilylamine, a hydrazine selected from Me2NNH2, MeHNNMeH, tBuHNNFh, N(SiH3)3, B2H6, Si2He, radicals thereof, and mixtures thereof. Preferably, the reducing agent is H2 or NH3. An inert gas selected from N2, He, Ar, Kr, Xe may be used as the carrier gas and / or the dilute gas.

[0036] Note that herein, the terms “precursor” and “deposition compound” and “deposition gas” may be used interchangeably when the precursor is in a gaseous state at room temperature and ambient pressure. It is understood that a precursor may correspond to, or be related to a deposition compound or deposition gas, and that the deposition compound or deposition gas may refer to the precursor.

[0037] The standard abbreviations of the elements from the periodic table of elements are used herein. It should be understood that elements may be referred to by these abbreviation (e.g., Si refers to silicon, N refers to nitrogen, O refers to oxygen, C refers to carbon, H refers to hydrogen, F refers to fluorine, etc.).

[0038] As used herein, the term “hydrocarbon” refers to a saturated or unsaturated function group containing exclusively carbon and hydrogen atoms. As used herein, the term “alkyl group” refers to saturated functional groups containing exclusively carbon and hydrogen atoms. An alkyl group is one type of hydrocarbon. Further, the term “alkyl group” refers to linear, branched, or cyclic alkyl groups. Examples of linear alkyl groups include without limitation, methyl groups, ethyl groups, propyl groups, butyl groups, etc. Examples of branched alkyls groups include without limitation, t-butyl. Examples of cyclic alkyl groups include without limitation, cyclopropyl groups, cyclopentyl groups, cyclohexyl groups, etc.

[0039] As used herein, the term “alkyl group” refers to saturated functional groups containing exclusively carbon and hydrogen atoms. Further, the term “alkyl group” refers to linear, branched, or cyclic alkyl groups. Examples of linear alkyl groups include without limitation, methyl groups, ethyl groups, propyl groups, butyl groups, etc. Examples of branched alkyls groups include without limitation, t-butyl. Examples of cyclic alkyl groups include without limitation, cyclopropyl groups, cyclopentyl groups, cyclohexyl groups, etc.

[0040] As used herein, the abbreviation “Me” refers to a methyl group; the abbreviation “Et” refers to an ethyl group; the abbreviation “Pr” refers to a propyl group;the abbreviation “nPr” refers to a “normal” or linear propyl group; the abbreviation “iPr” refers to an isopropyl group; the abbreviation “Bu” refers to a butyl group; the abbreviation “nBu” refers to a “normal” or linear butyl group; the abbreviation “tBu” refers to a tert-butyl group, also known as 1 ,1 -dimethylethyl; the abbreviation “sBu” refers to a sec-butyl group, also known as 1 -methylpropyl; the abbreviation “iBu” refers to an iso-butyl group, also known as 2-methylpropyl; the abbreviation “amyl” refers to an amyl or pentyl group; the abbreviation “tAmyl” refers to a tert-amyl group, also known as 1 ,1 -dimethylpropyl.

[0041] Please note that the metal-containing (e.g., Hf, Zr) films or layers deposited, such as hafnium oxide or zirconium nitride, may be listed throughout the specification and claims without reference to their proper stoichiometry (e.g., HfO = HfO2). These layers may also contain Hydrogen, typically from 0 atomic % to 15 atomic %. However, since not routinely measured, any film compositions given ignore their H content, unless explicitly stated otherwise. Furthermore, the concentration of hydrogen may be further tuned by performing post deposition annealing to obtain desired thin film properties.

[0042] Ranges may be expressed herein as from about one particular value, and / or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and / or to the other particular value, along with all combinations within said range. Any and all ranges recited herein are inclusive of their endpoints (i.e., x=1 to 4 or x ranges from 1 to 4 includes x=1 , x=4, and x=any number in between), irrespective of whether the term “inclusively” is used.

[0043] Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. The same applies to the term “implementation.”

[0044] As used herein, the term “independently” when used in the context of describing R groups should be understood to denote that the subject R group is not only independently selected relative to other R groups bearing the same or different subscripts or superscripts, but is also independently selected relative to any additionalspecies of that same R group. For example in the formula MR1X(NR2R3)(4-X), where x is 2 or 3, the two or three R1groups may, but need not be identical to each other or to R2or to R3. Further, it should be understood that unless specifically stated otherwise, values of R groups are independent of each other when used in different formulas.

[0045] As used in this application, the word “exemplary” is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Rather, use of the word exemplary is intended to present concepts in a concrete fashion.

[0046] Additionally, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or”. That is, unless specified otherwise, or clear from context, “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then “X employs A or B” is satisfied under any of the foregoing instances. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from context to be directed to a singular form.

[0047] "Comprising" in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing (i.e., anything else may be additionally included and remain within the scope of “comprising”). “Comprising” is defined herein as necessarily encompassing the more limited transitional terms "consisting essentially of" and “consisting of”; “comprising” may therefore be replaced by "consisting essentially of" or “consisting of” and remain within the expressly defined scope of “comprising”.

[0048] “Providing” in a claim is defined to mean furnishing, supplying, making available, or preparing something. The step may be performed by any actors in the absence of express language in the claim to the contrary.Brief Description of the Drawings

[0049] For a further understanding of the nature and objects of the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements are given the same or analogous reference numbers and wherein:FIG. 1 is a Thermo Gravimetric Analysis (TGA) graph demonstrating the percentageof weight with increasing temperature of Hf(‘BuCp)Cl3;FIG. 2 is a TGA graph demonstrating the percentage of weight with increasing temperature of Hf(sPentylCp)Cl3;FIG. 3 is a TGA graph demonstrating the percentage of weight with increasing temperature of Zr(sPentylCp)Cl3;FIG. 4 is growth rates of HfO2 films deposited using Hf(Cp)(NMe2)3, Hf(nPrCp)(NMe2)3 and Hf(sPentylCp)Cl3with ozone demonstrating ALD window for each precursor as a function of temperature;FIG. 5 is XPS analysis of HfO2 film deposited using Hf (sPentylCp)Cl3with ozone;FIG. 6 is carbon contents of HfO2 films deposited using Hf(Cp)(NMe2)3, Hf(nPrCp)(NMe2)3 or Hf(sPentylCp)Cl3 with ozone for selected conditions analyzed by TOF-SIMS;FIG. 7 is hydrogen contents of HfO2 films deposited using Hf(Cp)(NMe2)3, Hf(nPrCp)(NMe2)3 or Hf(sPentylCp)Cl3 with ozone for selected conditions analyzed by TOF-SIMS;FIG. 8 is XRD analysis of HfO2 films deposited from Hf(sPenCP)C and O3 at selected conditions; andFIG. 9 is a block diagram of a liquid precursor delivery system.Description of Preferred Embodiments

[0050] Disclosed are metal-containing film-forming compositions comprising metal chloride precursors, methods of synthesizing the metal chloride precursors, and methods of forming metal-containing films via chemical vapor deposition (CVD) processes, such as atomic layer deposition (ALD) process, using the metal-containing film-forming compositions. More specifically, the disclosed are the metal chloride precursors that have low melting point with a good ALD process performance in a temperature higher than 400°C.

[0051] The disclosed metal chloride precursors have the formula: M(R1R2R3R4R5Cp)xCly wherein, M is a transition metal, a rare earth element, an alkali metal, or an alkaline earth metal, preferably, M is a transition metal; more preferably, M is Hf or Zr; R1, R2, R3, R4and R5each are independently selected from a hydrogen atom, a Ci to Cw linear or branched alkyl-g rou p, a C3-C10 cyclic alkyl- group, or F, Si, Ge containing Ci-Cio linear and branched alkyl chain; x and y are integers; provided that x+y equals to the oxidation state of M.

[0052] More specifically, the disclosed metal chloride precursors have the formula: M(R1R2R3R4R5Cp)xClywherein, M is Hf or Zr; R1, R2, R3, R4and R5each are independently selected from a hydrogen atom, a Ci to C10 linear or branched alkyl-group, a C3 to C10 cyclic alkylgroup, or F, Si, Ge containing Ci to C10 linear and branched alkyl chain, provided that at least one of the R1, R2, R3, R4and R5is selected from a C5 to C10 linear or branched alkyl-group; x and y are integers; provided that x+y equals to 4. Preferably, x equals to 1 , y equals to 3. The disclosed metal chloride precursors include M(sPentylCp)Cl3, wherein M is Hf or Zr.

[0053] Exemplary disclosed metal chloride precursors include Zr(RCp)Cl3 and Hf(RCp)Cls, wherein R is selected from a hydrogen atom, a Ci to C10 linear or branched alkyl-group, a C3-C10 cyclic alkyl- group, or a F, Si, Ge containing C1-C10 linear and branched alkyl-group, provided that at least one of the R1, R2, R3, R4and R5is selected from a C5 to C10 linear or branched alkyl-group. For example, Zr(nPrCp)CI3, Zr(sBuCp)CI3, Zr(‘BuCp)Cl3, Zr(sPentylCp)CI3, Hf(sPentylCp)CI3, Hf(sBuCp)CI3, Hf(‘BuCp)Cl3, or the like.

[0054] Syntheses of some Hf(RCp)Cb and Zr(RCp)Cl3 precursors (wherein R is selected from a hydrogen atom, a Ci to C10 linear or branched alkyl-group, a C3-C10 cyclic alkyl- group, F, Si, Ge containing C1-C10 linear and branched alkyl chain, or the like, provided that at least one of the R1, R2, R3, R4and R5is selected from a C5 to C10 linear or branched alkyl-group), and the deposition of metal containing film with the metal chloride precursors (e.g., Hf(RCp)Cl3 and Zr(RCp)Cl3 precursors) are described here, and the Examples that follow. Here Zr(nPrCp)Cl3, Zr(sBuCp)Cl3, Zr(’BuCp)Cl3, Zr(sPentylCp)Cl3 were synthesized, and their physical properties are shown in Table 1Table 1

[0055] Regarding Hf precursors, Hf(sBuCp)Cb, Hf(tBuCp)Cl3, Hf(sPentylCp)Cl3 were synthesized. It is found that Hf(sPentylCp)Cl3 has dramatically low melting point comparing to Hf(RCp)Cb series as shown in Table 2. Low melting point of Hf(sPentylCp)Cl3 provides a significant advantage compared to other Hf(RCp)Cl3 For example, the precursors with low melting points behave as liquids in heated canisters, which allows it to be delivered with more consistent vapor pressure, which in turn improves deposited film properties, such as uniformity and purity.Table 2

[0056] The disclosed metal chloride precursors include ZrCpCL Zr(nPrCp)Cl3, Zr(tBuCp)Cb, Zr(sBuCp)Cb, Zr(sPentylCp)CI3, Hf(‘BuCp)CI3, Hf(sBuCp)CI3, and Hf(sPentylCp)Cb.

[0057] The disclosed metal chloride precursors may be M(sPentylCp)Cl3, wherein M is Hf or Zr.

[0058] The disclosed metal chloride precursor may be Hf(sPentylCp)Cl3.

[0059] The disclosed metal chloride precursor may be Zr(sPentylCp)Cl3.

[0060] The disclosed metal chloride precursor may be Hf(tBuCp)Cb.

[0061] When doing ALD evaluations with ozone, Hf(sBuCp)Cl3 does not show anyALD behavior, but the ALD windows may be confirmed for Hf(tBuCp)Cls andHf(sPentylCp)Cl3. Hf(sPentylCp)Cl3 shows particularly promising ALD results. It shows an ALD window (see FIG. 4) up to 500°C with excellent step coverage (100%) on a SiOs wafer (aspect ratio 25:1 ) (SEM image (not shown)) for Hf(sPentylCp)Cl3. For comparison Hf(Cp)(NMe2)3 demonstrates ALD window up to around 300°C as it shown on FIG. 4.

[0062] It is found that Hf(sPentylCp)Cl3 has the advantage of not only having a low melting point, 34°C, but also good ALD performance. Hf(sPentylCp)Cl3 may be one of the greatest alternative precursors for HfCL especially for high temperature ALD process.

[0063] The disclosed metal-containing film formed by deposition of the metalcontaining film-forming composition containing a metal chloride precursor may be a metal oxide, for example, HfCk, ZrO2, HfSiOx, HfMOx (M is usually a transition metal, e.g., Zr, x is integer), a metal nitride, for example, HfN, ZrN, other metal-containing films such as HfSi, or other alloys.

[0064] The disclosed metal chloride precursors have the flowing advantages. The disclosed metal chloride precursors may have low melting point, so that they may be liquid with just a little heating. Furthermore, not only does it has low melting point, but it also has good ALD results such as high ALD window, good film properties such as low impurity level and good crystallinity.

[0065] The disclosed metal chloride precursors may be synthesized from metal chloridecholide source, such as HfCL for Hf chloride precursors. For example, the disclosed precursor Hf(sPentylCp)Cl3 may be synthesized by reacting HfCL withsPentylCpTMS in toluene.

[0066] Purity of the disclosed metal-containing film-forming composition including the disclosed metal chloride precursors is greater than 95% w / w (i.e., 95.0% w / w to 100.0% w / w), preferably greater than 98% w / w (i.e., 98.0% w / w to 100.0% w / w), and more preferably greater than 99% w / w (i.e., 99.0% w / w to 100.0% w / w). One of ordinary skill in the art will recognize that the purity may be determined by H NMR and gas liquid chromatography with mass spectrometry. The disclosed metal-containing film-forming composition may contain any of the following impurities: pyrazoles; pyridines; alkylamines; alkylimines; THF; ether; pentane; cyclohexane; heptanes; benzene; toluene; chlorinated metal compounds; lithium, sodium, potassium pyrazolyl. The total quantity of these impurities is preferably below 5% w / w (i.e., 0.0% w / w to 5.0% w / w), preferably below 2% w / w (i.e., 0.0% w / w to 2.0% w / w), and more preferablybelow 1 % w / w (i.e., 0.0% w / w to 1.0% w / w). The composition may be purified by recrystallisation, sublimation, distillation, and / or passing the gas liquid through a suitable adsorbent, such as a 4A molecular sieve.

[0067] Purification of the disclosed metal-containing film-forming composition may also result in metal impurities at the 0 ppbw to 1 ppmw, preferably 0-500 ppbw (part per billion weight) level. These metal impurities may include, but are not limited to, Aluminum (Al), Arsenic (As), Barium (Ba), Beryllium (Be), Bismuth (Bi), Cadmium (Cd), Calcium (Ca), Chromium (Cr), Cobalt (Co), Copper (Cu), Gallium (Ga), Germanium (Ge), Hafnium (Hf), Zirconium (Zr), Indium (In), Iron (Fe), Lead (Pb), Lithium (Li), Magnesium (Mg), Manganese (Mn), Tungsten (W), Nickel (Ni), Potassium (K), Sodium (Na), Strontium (Sr), Thorium (Th), Tin (Sn), Titanium (Ti), Uranium (U), and Zinc (Zn).

[0068] Also disclosed are methods for forming metal-containing layers on a substrate using a vapor deposition process. Applicants believe, and demonstrate in the Deposition Example that follows, that the disclosed metal-containing film-forming compositions are suitable for atomic layer deposition (ALD). More particularly, the disclosed metal-containing film-forming compositions are capable of surface saturation, self-limited growth per cycle, and perfect step coverage on aspect ratios ranging from approximately 2:1 to approximately 200:1 , and preferably from approximately 20:1 to approximately 100:1. Additionally, the disclosed metalcontaining film-forming compositions have high decomposition temperatures, indicating good thermal stability to enable ALD. The high decomposition temperatures permit ALD at higher temperatures, resulting in films having higher purity.

[0069] The disclosed method may be useful in the manufacture of semiconductor devices, photovoltaics, LCD-TFTs, flat panel type devices. The disclosed metalcontaining film-forming compositions may be used to deposit metal-containing films using any deposition methods known to those of skill in the art. Examples of suitable deposition methods include chemical vapor deposition (CVD). Exemplary CVD methods include thermal CVD, plasma enhanced CVD (PECVD), pulsed CVD (PCVD), low pressure CVD (LPCVD), sub-atmospheric CVD (SACVD) atmospheric pressure CVD (APCVD), hot-wire CVD (HWCVD, also known as cat-CVD, in which a hot wire serves as an energy source for the deposition process), radicals incorporated CVD, ALD, thermal ALD, plasma enhanced ALD (PEALD), spatial ALD, hot-wire ALD (HWALD), radicals incorporated ALD, and combinations thereof, Super critical fluid deposition may also be used. The deposition method is preferably ALD, PEALD, orspatial ALD in order to provide suitable step coverage and film thickness control. For plasma enhanced depositions, the plasma may include any existing and emerging plasma sources including direct or remote plasma sources that may be applied to coreactants and the disclosed metal-containing film-forming compositions including the disclosed metal chloride precursors.

[0070] The disclosed metal-containing film-forming compositions may be supplied either in neat form in a blend with a suitable solvent, such as ethyl benzene, xylene, mesitylene, decalin, decane, dodecane, n-Octane. The disclosed metal chloride precursors may be present in varying concentrations in the solvent.

[0071] The neat or blended disclosed metal-containing film-forming compositions are introduced into a reactor in vapor form by conventional means, such as tubing and / or flow meters. The vapor form may be produced by vaporizing the neat or blended composition through a conventional vaporization step such as direct vaporization, distillation, by bubbling, or by using a sublimator. The neat or blended composition may be fed in liquid state to a vaporizer where it is vaporized before it is introduced into the reactor. Alternatively, the neat or blended composition may be vaporized by passing a carrier gas into a container containing the composition by bubbling the carrier gas into the composition. The carrier gas may include, but is not limited to, Ar, He, N2, and mixtures thereof. Bubbling with a carrier gas may also remove any dissolved oxygen present in the neat blended composition. The carrier gas and composition are then introduced into the reactor as a vapor,

[0072] If necessary, the container containing the disclosed metal-containing filmforming compositions may be heated to a temperature that permits the composition to be in its liquid phase and to have a sufficient vapor pressure. The container may be maintained at temperatures in the range of, for example, approximately 0°C to approximately 200°C. Those skilled in the art recognize that the temperature of the container may be adjusted in a known manner to control the amount of precursor vaporized.

[0073] The reactor may be any enclosure chamber within a device in which deposition methods take place such as without limitation, a parallel-plate type reactor, a cold-wall type reactor, a hot-wall type reactor, a single-wafer reactor, a multi-wafer reactor, a powder ALD reactor, other types of deposition systems under conditions suitable to cause the compounds to react and form the deposition films. One of ordinary skill in the art will recognize that any of these reactors may be used for eitherALD or CVD deposition processes.

[0074] The reactor contains one more substrates onto which the films will be deposited. A substrate is generally defined as a material on which a process is conducted. The substrates may be any suitable substrate used in semiconductor, photovoltaic, flat panel, LCD-TFT device manufacturing. Examples of suitable substrates include wafers, such as silicon, silica, glass, GaAs wafers. The wafer may have one more layers of differing materials deposited on it from a previous manufacturing step. For example, the wafers may include a dielectric layer. Furthermore, the wafers may include silicon layers (crystalline, amorphous, porous, etc.,), silicon oxide layers, silicon nitride layers, silicon oxy nitride layers, carbon doped silicon oxide (SiCOH) layers, metal, metal oxide, metal nitride layers (Ti, Ru, Ta, etc.) and combinations thereof. Additionally, the wafers may include copper layers noble metal layers (e.g., platinum, palladium, rhodium, and gold). Plastic layers may also be used. The layers may be planar or patterned. The disclosed processes may deposit the metal-containing layer directly on the wafer or directly on one or more layers on top of the wafer (when patterned layers form the substrate). Furthermore, one of ordinary skill in the art will recognize that the terms “film” and “layer” used herein refer to a thickness of some material laid on spread over a surface and that the surface may be a hole, a trench or a line. Throughout the specification and claims, the wafer and any associated layers thereon are referred to as substrates.

[0075] The substrate may also be a powder, such as the powder used in rechargeable battery technology. A non-limiting number of powder materials include LNMC (Lithium Nickel Manganese Cobalt Oxide), LCO (Lithium Cobalt Oxide), LFP (Lithium Iron Phosphate), and other battery cathode materials.

[0076] The temperature and the pressure within the reactor are held at conditions suitable for ALD. In other words, after introduction of the vaporized disclosed composition into the chamber, conditions within the chamber are such that at least part of the precursor is deposited onto the substrate to form a metal-containing layer. For instance, the pressure in the reactor or the deposition pressure may be held between about 10'3torr and about 100 Torr, more preferably between about 10'2and 100 Torr, as required per the deposition parameters. Likewise, the temperature in the reactor or the deposition temperature may be held between about 100°C and about 800°C, preferably between about 150°C and about 600°C, more preferably between about 400°C and about 600°C. Alternatively, the temperature in the reactor or thedeposition temperature may be held higher than 100°C, preferably higher than 400°C. One of ordinary skill in the art will recognize that “at least part of the precursor is deposited” means that some all of the precursor reacts with adheres to the substrate.

[0077] The temperature of the reactor may be controlled by either controlling the temperature of the substrate holder or controlling the temperature of the reactor wall. Devices used to heat the substrate are known in the art. The reactor wall is heated to a sufficient temperature to obtain the desired film at a sufficient growth rate and with desired physical state and composition. A non-limiting exemplary temperature range to which the reactor wall may be heated includes higher than 50°C, preferably higher than 400°C. Alternatively, a non-limiting exemplary temperature range to which the reactor wall may be heated includes from approximately 50°C to approximately 800°C, preferably from approximately 400°C to approximately 600°C. When a plasma deposition process is utilized, the deposition temperature may range from approximately 50°C to approximately 800°C, preferably, from approximately 100°C to approximately 600°C, more preferably, from approximately 400°C to approximately 600°C. Alternatively, when a thermal process is performed, the deposition temperature may be higher than 100°C, preferably, higher than 400°C, or the deposition temperature may range from approximately 100°C to approximately 600°C, preferably from approximately 400°C to approximately 600°C.

[0078] In addition to the disclosed metal-containing film-forming composition, a coreactant may be introduced into the reactor. When a target is a conductive film, the co-reactant may be a reducing agent selected from H2, H2CO, N2, NH3, N2H2, N2H4, N2O, a primary amine, a secondary amine, a tertiary amine, trisilylamine, a hydrazine selected from Me2NNH2, MeHNNMeH, tBuHNNH2, N(SiH3)3, B2H6, Si2H6, radicals thereof, and mixtures thereof. Preferably, the reducing agent is N2, H2 or NH3, more preferably, the reducing agent is NH3. More preferably, the reducing agent is NH3. Alternatively, when a target is a dielectric film, the co-reactant may be an oxidizing gas or an oxidizer selected from O2, O3, H2O, H2O2, NO, N2O, NO2, oxygen containing radicals such as O- OH-, carboxylic acids, formic acid, acetic acid, propionic acid, or mixtures thereof. Preferably, the oxidizing gas is selected from the group consisting of O3, H2O2 and H2O. More preferably, the oxidizing gas is O3.

[0079] The co-reactant may be treated by a plasma, in order to decompose the reactant into its radical form, N2 may also be utilized as a nitrogen source gas when treated with plasma. For instance, the plasma may be generated with a power rangingfrom about 10 W to about 1000 W, preferably from about 50 W to about 500 W. The plasma may be generated present within the reactor itself. Alternatively, the plasma may generally be at a location remote from the reactor, for instance, in a remotely located plasma system. One of skill in the art will recognize methods and apparatus suitable for such plasma treatment.

[0080] For example, the co-reactant may be introduced into a direct plasma reactor, which generates plasma in the reaction chamber, to produce the plasma- treated reactant in the reaction chamber. The co-reactant may be introduced and held in the reaction chamber prior to plasma processing. Alternatively, the plasma processing may occur simultaneously with the introduction of the reactant. In-situ plasma is typically a 13.56 MHz RF capacitively coupled plasma that is generated between the showerhead and the substrate holder. The substrate and the showerhead may be the powered electrode depending on whether positive ion impact occurs. Typical applied powers in in-situ plasma generators are from approximately 30 W to approximately 1000 W. Preferably, powers from approximately 30 W to approximately 600 W are used in the disclosed methods. More preferably, the powers range from approximately 100 W to approximately 500 W. The disassociation of the co-reactant using in-situ plasma is typically less than achieved using a remote plasma source for the same power input and is therefore not as efficient in reactant dissociation as a remote plasma system, which may be beneficial for the deposition of metal-containing films on substrates easily damaged by plasma.

[0081] Alternatively, the plasma-treated co-reactant may be produced outside of the reaction chamber, for example, a remote plasma to treat the co-reactant prior to passage into the reaction chamber.

[0082] The disclosed metal-containing film-forming composition including the disclosed metal chloride precursors may also be treated by a plasma as the co- reactant is treated by a remote plasma system, in-situ plasma or a direct plasma, for example, when a PEALD process is applied.

[0083] The ALD conditions within the chamber allow the disclosed metal-containing film-forming composition adsorbed chemisorbed on the substrate surface to react and form a metal-containing film on the substrate. In some embodiments, it is believed that plasma-treating the co-reactant may provide the co-reactant with the energy needed to react with the disclosed metal-containing film-forming composition.

[0084] Depending on what type of film is desired to be deposited, an additionalprecursor compound may be introduced into the reactor. The additional precursor may be used to provide additional elements to the metal-containing film. The additional elements may include Group I elements (lithium, Sodium, potassium), lanthanides (Ytterbium, Erbium, Dysprosium, Gadolinium, Praseodymium, Cerium, Lanthanum, Yttrium), Group IV elements (zirconium, titanium, hafnium), main group elements (germanium, silicon, aluminum), additional different Group V elements, and mixtures thereof. When an additional precursor compound and the metal chloride precursors is utilized, the resultant film deposited on the substrate contains metal-containing compositions in combination with an additional element from the additional precursor. When the additional precursor and the metal chloride precursors are used in more than one ALD super cycle sequences, a nanolaminate film is obtained. For instance, when an additional Li-containing precursor is used, the metal-containing film will contain Li, such as, a lithium hafnium containing LiHfOx(x = 2 - 3) film. One of ordinary skilled in the art will recognize the metal-containing films containing Li may be formed by ALD on any types of substrates including a powder.

[0085] The disclosed metal-containing film-forming compositions and co-reactants may be introduced into the reactor sequentially (i.e., ALD). The reactor may be purged with an inert gas (e.g., N2, He, Ar, Kr, or Xe) between the introduction of each of the disclosed metal-containing film-forming compositions, any additional precursors, and the co-reactants. Another example is to introduce the co-reactant continuously and to introduce the metal-containing film-forming composition by pulse, while activating the co-reactant sequentially with a plasma, provided that the metal-containing film-forming composition and the non-activated co-reactant do not substantially react at the chamber temperature and pressure conditions (CW PEALD).

[0086] Each pulse of the disclosed metal-containing film-forming compositions may last more than 0.01 seconds, preferably for a time period ranging from about 0.01 seconds to about 10 minutes, preferably from about 1 seconds to about 5 minutes, more preferably from about 1 minute to about 4 minutes. The co-reactant may also be pulsed into the reactor, In such embodiments, the pulse of each may last for a time period ranging from about 0.01 seconds to about 120 seconds, alternatively from about 1 seconds to about 30 seconds, alternatively from about 2 seconds to about 20 seconds. In another alternative, the vaporized disclosed metal-containing film-forming compositions and co-reactants may be simultaneously sprayed from different sectors of a shower head (without mixing of the composition and the reactant) under which asusceptor holding several wafers is spun (spatial ALD).

[0087] Depending on particular process parameters, deposition may take place for a varying length of time. Generally, deposition may be allowed to continue as long as desired necessary to produce a film with the necessary properties. Typical film thicknesses may vary from several angstroms to several hundreds of microns, and typically from 0.1 to 100 nm, depending on the specific deposition process. The deposition process may also be performed as many times as necessary to obtain the desired film.

[0088] In one non-limiting exemplary ALD process, the vapor phase of the disclosed metal-containing film-forming compositions is introduced into the reactor, where it is contacted with a suitable substrate. Excess composition may then be removed from the reactor by purging and / or evacuating the reactor. A co-reactant (for example, O3) is introduced into the reactor where it reacts with the absorbed metalcontaining film-forming composition in a self-limiting manner. Any excess co-reactant is removed from the reactor by purging and / or evacuating the reactor. If the desired film is a metal oxide, this two-step process may provide the desired film thickness may be repeated until a film having the necessary thickness has been obtained.

[0089] When the co-reactant in this exemplary ALD process is treated with a plasma, the exemplary ALD process becomes an exemplary PEALD process. The coreactant may be treated with plasma prior subsequent to introduction into the chamber.

[0090] Upon obtaining a desired film thickness, the film may be subject to further processing, such as thermal annealing, furnace-annealing, rapid thermal annealing, UV e-beam curing, and microwave annealing and / or plasma gas exposure. Those skilled in the art recognize the systems and methods utilized to perform these additional processing steps. For example, the HfO film may be exposed to a temperature ranging from approximately 200°C and approximately 1000°C for a time ranging from approximately 0.1 second to approximately 7200 seconds under an inert atmosphere, an O-containing atmosphere, H-containing atmosphere combinations thereof. Most preferably, the temperature is 400°C for 3600 seconds under an inert atmosphere or an O-containing atmosphere. The resulting film may contain fewer impurities and therefore may have an improved density resulting in improved leakage current. The annealing step may be performed in the same reaction chamber in which the deposition process is performed. Alternatively, the substrate may be removed from the reaction chamber, with the annealing / flash annealing process being performed ina separate apparatus. Any of the above post-treatment methods, but especially thermal annealing, has been found effective to reduce carbon and nitrogen contamination of HfOs film. This in turn tends to improve the resistivity of the film.

[0091] In another alternative, the disclosed metal chloride precursors may be used as doping implantation agents. Part of the disclosed metal-containing film-forming composition may be deposited on top of the film to be doped, such as hafnium oxide or zirconium nitride. The metal element, for example Li, then diffuses into the film during an annealing step to form the metal element-doped films, such as LiHfOx, LiZrOx (x=2-3).

[0092] In one embodiment, the metal-containing film-forming composition, specifically, the disclosed metal chloride precursor, is delivered as a liquid to processing equipment or processing chamber 106, as shown in FIG. 9, by the means of pressurizing the disclosed metal chloride precursor in high purity vessel 102 with an inert gas while keeping the disclosed metal chloride precursor above its melting point, to feed processing equipment 106 with the liquid precursor. The inert gas may be selected from Ar, He, N2and mixtures thereof. As shown in FIG. 9, the disclosed metal chloride precursor is pressurized in high purity vessel 102 and delivered to processing equipment 106 through delivery line 104 or delivered to bubbler 108 mounted in processing equipment 106. High purity vessel 102 may be made of stainless steel. The disclosed metal chloride precursors may be heated above its melting point at a temperature ranging from 30 to 80°C, and preferably from 40 to 60°C. The liquid precursor may be fed directly into processing equipment 106 by direct liquid injection or vaporization, or may be fed into bubbler 108 mounted into processing equipment 106 and kept inside bubbler 108 at a temperature sufficient to deliver vapors to processing equipment 106.

[0093] The disclosed metal chloride precursors may be heated to a temperature at which its viscosity is lower than 30cP, preferably lower than 10cP, to ensure proper delivery as a liquid from the high purity vessel to the bubbler or to the processing equipment.

[0094] In yet another embodiment, the disclosed metal-containing film-forming composition including new metal chloride precursors such as Hf(sPentylCp)Cl3 and Zr(sPentylCp)Cls could be used for yet other utilizations, such as polyolefin catalysts, inorganic coatings, formation of Hf and Zr materials or any other uses.Examples

[0095] The following non-limiting examples are provided to further illustrate embodiments of the invention. However, the disclosed methods are not limited to presented examples in any way and process conditions, process precursor, carrier gas, co-remantant, combination and proportion of precursors, co-reactants and gases, deposition process conditions, workpiece and deposition chamber itself may be altered. Deposition conditions, deposition chamber and workpiece together with results of deposition process are described below.

[0096] < Deposition device>

[0097] In the disclosed methods, a single wafer showerhead type reactor was used for deposition experiments. Reactor chamber was maintained at regulated pressure and temperature to enable deposition process.

[0098] <Deposition condition>

[0099] During deposition process wafer temperature was maintained in a range between 200 and 550°C, chamber pressure was maintained in a range between 0.5 and 1 torr, disclosed metal precursor was supplied to a chamber utilizing flow of carrier gas and co-reactant was supplied to a chamber directly. During the deposition process introduction of metal precursor was altered with introduction of co-reactant separated by purge steps in a cyclic manner.Example 1. Synthesis

[0100] HfCU (114.3 g, 0.36 mol) was dissolved in toluene (800 mL) in a 2 L schlenk flask. After dissolution of ‘BuCpTMS (69.4 g, 0.36 mol) in toluene (150 mL), ‘BuCpTMS solution was added dropwise to the HfCU solution in a dry ice bath. The mixture was allowed to warm-up to room temperature overnight with stir to give a dark brown suspension. The organic toluene solvent was removed under vacuum (~40 mTorr) at 40°C to give a crude dark brown solid. The dark brown solid was sublimed under vacuum with a cold trap. The product of the dark brown solid was sublimed at ~100°C at 30 mTorr resulting in 68.7 g (0.17 mol) of yellow solid with 47% yield.

[0101] The product was characterized by NMR1H (6, ppm, CeDe): 6.60-5.76 (tt, 4H). 1.05 (s, 9H). FIG. 1 shows A Thermo Gravimetric Analysis (TGA) graph demonstrating the percentage of weight with increasing temperature of Hf(lBuCp)Cl3.Example 2. Synthesis of Hf(sPentylCp)Cl3

[0102] HfC (81 .7 g, 0.26 mol) was dissolved in toluene (600 mL) in a 2 L schlenk flask. After dissolution ofsPentylCpTMS (53.3 g, 0.26 mol) in toluene (120 mL),sPentylCpTMS solution was added dropwise to the HfCL solution in a dry ice bath. The mixture was allowed to warm-up to room temperature overnight with stir to give a dark brown suspension. The organic toluene solvent was removed under vacuum (-40 mTorr) at 40°C to give a crude dark brown solid. The dark brown solid was sublimed under vacuum with a cold trap. The dark brown solid was sublimed at ~100°C at 30 mTorr resulting in a product of 57.5 g (0.14 mol) of yellow solid with 53% yield.

[0103] The product was characterized by NMR1H (0, ppm, CeDe): 5.92-5.75 (tt, 4H). 2.75 (m, 2H). 1 .24 (m, 2H). 1 .09 (m, 2H). 1 .00 (d, 3H). 0.74 (t, 3H). FIG. 2 shows a ThermoGravimetric Analysis (TGA) graph demonstrating the percentage of weight with increasing temperature of Hf(sPentylCp)Cb.Example 3. Synthesis of Zr(sPentylCp)Cl3

[0104] ZrCL (12.5 g, 0.0536 mol) was dissolved 100 mL of toluene and cooled to - 65°C. A solution ofsPentylCpTMS (12.3 g, 0.059 mol) dissolved in toluene (20 mL) was added dropwise to the ZrCL solution. The mixture was stirred at room temperature for overnight. After the reaction, solvent was removed under vacuum (-35 mTorr) at40°C to give a crude dark brown solid. The crude was sublimed under vacuum with a cold trap, then the product was sublimed at ~120°C at 35 mTorr resulting in a product of 1.17 g of Yellow solid with 6.6% yield.

[0105] The product was characterized by NMR1H (5, ppm, CeDe): 6.23-6.12 (m, 4H). 3.06 (sext, 1 H). 1.14 (m, 2H). 1.18 (m, 2H). 1.12 (d, 3H).0.80 (t, 3H). FIG. 3 shows a ThermoGravimetric Analysis (TGA) graph demonstrating the percentage of weight with increasing temperature of Zr(sPentylCp)Cl3.Example 4. ALD using Hf(sPentylCp)Cl3with ozone

[0106] Deposition process was done using Hf(sPentylCp)Cl3 as a metal precursor and ozone as a co-reactant. Carrier gas was supplied to the reactor and precursor line through mass flow controllers. High purity argon was used both as a carrier gas to transfer precursor and as a purge gas to remove byproducts and excess gases from the reactor. Ozone concentration was 300 g / Nm3and flow rate was 1000 seem. Typically, the reactor was operated at 0.5 - 2 torr achieved by argon gas flow with a throttle valve. Introduction of the metal precursor was altered with introduction of the co-reactant with purge steps between. One introduction of the metal precursor followed by one introduction of the co-reactant was considered as a one cycle. Deposition process contained 100 cycles. Temperature of the workpiece varied in a range between 250 and 550°C. The resulting deposited film was an HfO2 film FIG. 4 dependence of growth per cycle as a function of a temperature for deposition process using Hf(sPentylCp)Cl3with ozone. Growth per cycle was estimated from the thickness of HfO2 film deposited. FIG. 5 shows XPS analysis showing film compositionimpurities after deposition process withfor Hf (sPentylCp)Cl3With ozone. Carbon content for HfO2 films deposited at selected conditions analysed by Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) is presented in FIG.6. Hydrogen content for HfO2 films deposited at selected conditions analysed by TOF-SIMS is presented in FIG. 7. FIG. 8 showing the influence of deposition temperature on HfO2 crystalline phase, which is a known phenomenon in the art, and demonstrated here as illustration only. It was confirmed by SEM (not shown) that the step coverage for deposition process using Hf(sPentylCp)Cls at 500°C was around 100% for trench patterned wafer with aspect ratio of 1 :25.Comparative Example 1

[0107] Deposition process was performed in the same way as Example 4 with exception that metal precursor was Hf(Cp)(NMe2)3. Results of the deposition tests are presented in FIG. 4, carbon content for selected conditions analysed by TOF- SIMS is presented in FIG. 6, hydrogen content for selected conditions analysed by TOF-SIMS is presented in FIG. 7.Comparative Example 2

[0108] Deposition process was performed in a same way as Example 4 with exception that metal precursor was Hf(nPrCp)(NMe2)3. Results of the deposition tests are presented in FIG. 4. Results of the deposition tests are presented in FIG. 4, showing that Hf(sPentylCp)Cl3 allowed to achieve ALD process starting from 350°C and maintained capability of ALD at temperatures above 450°C, when metal precursors from both comparative examples did not achieve ALD for temperatures above 450°C. This highlights advantage of Hf(sPentylCp)Cl3 for high temperature ALD process. Carbon content for selected conditions analysed by TOF-SIMS is presented in FIG. 6 is showing a lower C content achieved when depositing HfO2 with Hf(sPenCp)Ch vs. conventional N-containing precursor such as HfCp(NMe2)s. Hydrogen content for selected conditions analysed by TOF-SIMS is presented in FIG. 7 showing a lower H content achieved when depositing HfO2 with Hf(sPenCp)Cl3 vs. conventional N-containing precursor such as HfCp(NMe2)s. XRD analysis of films deposited at selected conditions is presented in FIG. 8 showing the influence of deposition temperature on HfO2 crystalline phase, highlighting that it is possible to achieve monoclinic and cubic phase. Monoclinic and cubic phase are generally favored at increased temperature, which is beneficial for the Hafnium oxide dielectric constant, therefore capability of deposition at high temperature with Hf(sPenCp)Cl3 is advantageous comparing to common Hf precursors.

[0109] Overall disclosed precursors for deposition of metal containing films, and Hf(sPenCp)Cl3 in particular, are demonstrating excellent thermal stability and low melting point which allows to improve quality of deposited films and makes precursor handling less complicated compared to common precursors.

[0110] It will be understood that many additional changes in the details, materials, steps, and arrangement of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the artwithin the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above and / or the attached drawings.

[0111] While embodiments of this invention have been shown and described, modifications thereof may be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments described herein are exemplary only and not limiting. Many variations and modifications of the composition and method are possible and within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims which follow, the scope of which shall include all equivalents of the subject matter of the claims.

Claims

2023P00470WQWhat is claimed is:1 . A method for forming a metal-containing film, the method comprising the steps of: a) exposing a substrate to a vapor of a metal-containing film-forming composition; b) exposing the substrate to a co-reactant; and c) repeating the steps of a) and b) until a desired thickness of the metalcontaining film is deposited on the substrate using a vapor deposition process, wherein the metal-containing film-forming composition comprises a metal chloride precursor having the formula:M(R1R2R3R4R5Cp)xClywherein, M is Hf or Zr; R1, R2, R3, R4and R5each are independently selected from a hydrogen atom, a Ci to Cw linear or branched alkyl-group, a C3 to C10 cyclic alkylgroup, or F, Si, Ge containing Ci to C10 linear and branched alkyl chain, provided that at least one of the R1, R2, R3, R4and R5is selected from a C5 to Cw linear or branched alkyl-group; x and y are integers; provided that x+y equals to 4.

2. The method of claim 1 , wherein a deposition temperature is higher than 400°C.

3. The method of claim 1 , wherein x equals to 1 , y equals to 3.

4. The method of claim 1 , wherein the metal chloride precursor is M(sPentylCp)Ch, wherein M is Hf or Zr.

5. The method of claim 1 , wherein the metal chloride precursor is Hf(sPentylCp)CI3.

6. The method of claim 1 , wherein the metal chloride precursor is Zr(sPentylCp)Cl3.

7. The method of claim 1 , wherein the co-reactant is selected from the group consisting of O2, O3, H2O, H2O2, NO, N2O, NO2, oxygen containing radicals selectedfrom O- OH-, carboxylic acids, formic acid, acetic acid, propionic acid, and mixtures thereof.

8. The method of claim 1 , wherein the co-reactant is O3.

9. The method of claim 1 , wherein the co-reactant is selected from the group consisting of H2, H2CO, N2, NH3, N2H2, N2H4, N2O, a primary amine, a secondary amine, a tertiary amine, trisilylamine, a hydrazine selected from Me2NNH2, MeHNNMeH, tBuHNNF , N(SiHs)3, B2H6, Si2Hs, radicals thereof, and mixtures thereof.

10. The method of claim 1 , wherein the co-reactant is NH3.11 . The method of claim 1 , wherein the metal-containing film is an HfC>2, HfN, ZrC>2 or ZrN film.

12. A method of depositing an MO2 or MN film or coating the MO2 or MN film on a substrate, the method comprising the steps of: a) exposing the substrate to a vapor of M(sPentylCp)Cl3; b) exposing the substrate to a co-reactant; c) repeating the steps of a) and b) until a desired thickness of the MO2 or MN film is formed on the substrate using an ALD process, wherein M is Hf or Zr.

13. The method of claim 12, further comprising the step of: introducing an inert gas purge following the steps a) and b), respectively, to separate each exposure, wherein the inert gas purge uses an inert gas selected from N2, He, Ar, Kr, orXe.

14. The method of claim 12, wherein a deposition temperature is higher than 400°C.

15. The method of claim 12, wherein the co-reactant is selected from the group consisting of O2, O3, H2O, H2O2, NO, N2O, NO2, oxygen containing radicals selected from O- OH-, carboxylic acids, formic acid, acetic acid, propionic acid, and mixtures thereof.

16. The method of claim 12, wherein the co-reactant is selected from the group consisting of H2, H2CO, N2, NH3, N2H2, N2H4, N2O, a primary amine, a secondary amine, a tertiary amine, trisilylamine, a hydrazine selected from Me2NNH2, MeHNNMeH, tBuHNNF , N(SiHs)3, B2H6, Si2Hs, radicals thereof, and mixtures thereof.

17. A metal-containing film-forming composition for a vapor deposition process comprising a precursor having the formula:M(R1R2R3R4R5Cp)xClywherein, M is Hf or Zr; R1, R2, R3, R4and R5each are independently selected from a hydrogen atom, a Ci to Cw linear or branched alkyl-group, a C3 to C10 cyclic alkylgroup, or F, Si, Ge containing Ci to C10 linear and branched alkyl chain, provided that at least one of the R1, R2, R3, R4and R5is selected from a C5 to Cw linear or branched alkyl-group; x and y are integers; provided that x+y equals to 4.

18. The metal-containing film-forming composition of claim 17, wherein x equals to 1 , y equals to 3.

19. The metal-containing film-forming composition of claim 17, wherein the precursor is selected from the group consisting of Hf(sPentylCp)Cl3 and Zr(sPentylCp)Cl3.

20. A composition comprising a precursor selected from the group consisting of Hf(sPentylCp)Cl3 and Zr(sPentylCp)Cl3.21 . The composition of claim 20, wherein the precursor is Hf(sPentylCp)Cl3.

22. The composition of claim 20, wherein the precursor is Zr(sPentylCp)C .

23. A method of providing a vapor of a liquid precursor Hf(sPentylCp)Cl3 or Zr(sPentylCp)Cl3 to a processing equipment, the method comprising the steps of:A. pressurizing a vessel containing the liquid precursor Hf(sPentylCp)Cl3 or Zr(sPentylCp)Cl3 with an inert gas selected from He, Ar, N2 or mixtures thereof, while keeping the temperature of the vessel and a delivery line from the vessel to the processing equipment above the melting point of the precursor;B. feeding the liquid precursor Hf(sPentylCp)Cl3 or Zr(sPentylCp)Cl3 directly into the processing equipment via the delivery line, by direct liquid injection or vaporization;C. alternatively, via the delivery line, refilling the liquid precursor Hf(sPentylCp)Cl3 or Zr(sPentylCp)Cl3 to a bubbler mounted in the processing equipment with and keeping the liquid in the bubbler at a temperature necessary to provide sufficient vapor to the process equipment.

24. The method of claim 23, wherein the vessel and the delivery line to the processing equipment are kept at a temperature that provides a viscosity of the precursor of less than 30 cP.

25. The method of claim 23, wherein the vessel and the delivery line to the processing equipment are kept at a temperature that provides a viscosity of the precursor of less than 10 cP.

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