Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
  • C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
  • C23C16/30—Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
  • C23C16/40—Oxides
  • C23C16/405—Oxides of refractory metals or yttrium
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
  • C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
  • C23C16/30—Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
  • C23C16/40—Oxides
  • C23C16/409—Oxides of the type ABO3 with A representing alkali, alkaline earth metal or lead and B representing a refractory metal, nickel, scandium or a lanthanide
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
  • C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
  • C23C16/455—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating characterised by the method used for introducing gases into reaction chamber or for modifying gas flows in reaction chamber
  • C23C16/45523—Pulsed gas flow or change of composition over time
  • C23C16/45525—Atomic layer deposition [ALD]
  • C23C16/45527—Atomic layer deposition [ALD] characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations
  • C23C16/45529—Atomic layer deposition [ALD] characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations specially adapted for making a layer stack of alternating different compositions or gradient compositions
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
  • C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
  • C23C16/455—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating characterised by the method used for introducing gases into reaction chamber or for modifying gas flows in reaction chamber
  • C23C16/45523—Pulsed gas flow or change of composition over time
  • C23C16/45525—Atomic layer deposition [ALD]
  • C23C16/45527—Atomic layer deposition [ALD] characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations
  • C23C16/45531—Atomic layer deposition [ALD] characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations specially adapted for making ternary or higher compositions
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G4/00—Fixed capacitors; Processes of their manufacture
  • H01G4/002—Details
  • H01G4/018—Dielectrics
  • H01G4/06—Solid dielectrics
  • H01G4/08—Inorganic dielectrics
  • H01G4/085—Vapour deposited
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G4/00—Fixed capacitors; Processes of their manufacture
  • H01G4/002—Details
  • H01G4/018—Dielectrics
  • H01G4/06—Solid dielectrics
  • H01G4/08—Inorganic dielectrics
  • H01G4/12—Ceramic dielectrics
  • H01G4/1209—Ceramic dielectrics characterised by the ceramic dielectric material
  • H01G4/1218—Ceramic dielectrics characterised by the ceramic dielectric material based on titanium oxides or titanates
  • H01G4/1227—Ceramic dielectrics characterised by the ceramic dielectric material based on titanium oxides or titanates based on alkaline earth titanates
• • H10P14/6334—
• • H10P14/69398—
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/02104—Forming layers
  • H01L21/02107—Forming insulating materials on a substrate
  • H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
  • H01L21/02112—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer
  • H01L21/02172—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing at least one metal element, e.g. metal oxides, metal nitrides, metal oxynitrides or metal carbides
  • H01L21/02175—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing at least one metal element, e.g. metal oxides, metal nitrides, metal oxynitrides or metal carbides characterised by the metal
  • H01L21/02186—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing at least one metal element, e.g. metal oxides, metal nitrides, metal oxynitrides or metal carbides characterised by the metal the material containing titanium, e.g. TiO2
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/02104—Forming layers
  • H01L21/02107—Forming insulating materials on a substrate
  • H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
  • H01L21/022—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/02104—Forming layers
  • H01L21/02107—Forming insulating materials on a substrate
  • H01L21/02225—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer
  • H01L21/0226—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process
  • H01L21/02263—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase
  • H01L21/02271—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition
  • H01L21/0228—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• • H10P14/6339—
• • H10P14/662—
• • H10P14/69394—

Definitions

• dielectric constant i.e., high dielectric permittivity
• Dielectric materials containing alkaline earth metals can provide a significant advantage in capacitance compared to conventional dielectric materials.
• a perovskite material, strontium titanate (SrTiO 3 ) has a disclosed bulk dielectric constant of up to 500.
• Figure 1 is a schematic side view of illustrating an embodiment of a metal-containing layer deposited on a substrate by atomic layer deposition methods as described in the present disclosure.
• Figure 2 is a perspective view of a vapor deposition system suitable for use in methods as described herein.
• Figure 3 is an example capacitor construction formed using methods as described herein.
• Figure 4 depicts an x-ray photoelectron spectrum (XPS) for an embodiment of a strontium titanate layer prepared by a method as described in Example 1.
• the spectrum is a plot of depth (nanometers; x-axis) versus atomic concentration (atomic percent; y-axis).
• Figure 5 is a plot illustrating x-ray diffraction data (XRD) for (5 a) an embodiment of a metal-containing layer prepared by a method as described in Comparative Example 1 ; and (5b) an embodiment of a metal-containing layer prepared by a method as described in Example 1.
• Figures 5a and 5b are plots of 2 theta (degrees; x-axis) versus intensity (arbitrary units or A. U.; y-axis).
• Figure 6 is a plot illustrating angle resolved x-ray photoelectron spectra for an oxygen multiplex graph (6a) and a carbon multiplex graph (6b) for an embodiment of a metal-containing layer prepared by a method as described in Comparative Example 1 (scan 1); and an embodiment of a metal- containing layer prepared by a method as described in Example 1 (scan 2).
• Figures 6a and 6b are plots of Binding Energy (electron volts or E. V.; x- axis) versus counts per second (y-axis).
• strontium titanate films having a substantially 1 : 1 atomic ratio of strontium:titanium are desired for producing defect free SrTiO 3 films that crystallize into the cubic phase upon annealing.
• the presence of the crystalline cubic phase can result in the high dielectric constants for which perovskite materials are known.
• carbon-containing impurities such as strontium carbonate (SrCO 3 )
• certain embodiments of the atomic layer deposition methods described herein can provide at least some of the desired properties.
• FIG. 1 is an illustration of a construction 100 that can be prepared by methods as disclosed herein.
• an initial titanium oxide deposition phase can deposit a layer of titanium oxide 120 on substrate 110.
• titanium oxide layer 120 can be less than 1 nanometer thick, and in other certain embodiments, at most 0.6 nanometer thick. In certain embodiments, titanium oxide layer 120 can be at least 0.3 nanometer thick.
• the initial titanium oxide deposition phase includes a plurality of titanium oxide deposition cycles. As used herein, "plurality" means two or more.
• the initial titanium oxide deposition phase consists of, or consists essentially of, a plurality of titanium oxide deposition cycles.
• the initial titanium oxide deposition phase can consist of from 11 to 14 titanium oxide deposition cycles.
• an intermediate deposition phase can deposit a layer of strontium oxide/titanium oxide 130 on titanium oxide layer 120.
• the thickness of the strontium oxide/titanium oxide layer 130 can be controlled as desired for a given application based on the number of deposition cycles employed.
• strontium oxide/titanium oxide layer 130 can be at least 1 nanometer thick, and in other embodiments at 2 nanometers thick.
• the maximum thickness of the strontium oxide/titanium oxide layer is limited only by the requirements of the specific application (e.g., 50 nanometers, 100 nanometers, or even thicker), in certain illustrative embodiments as described herein, the maximum thickness of the strontium oxide/titanium oxide layer 130 can be, for example, 20 nanometers, 30 nanometers, or 40 nanometers.
• the intermediate deposition phase includes a plurality of strontium oxide deposition cycles and a plurality of titanium oxide deposition cycles.
• the intermediate deposition phase can include alternating strontium oxide and titanium oxide deposition cycles.
• the intermediate deposition phase can include a plurality of consecutive strontium oxide deposition cycles alternating with a titanium oxide deposition cycle.
• the intermediate deposition phase can include a strontium oxide deposition cycle alternating with a plurality of consecutive titanium oxide deposition cycles.
• the intermediate deposition phase can include a plurality of consecutive strontium oxide deposition cycles alternating with a plurality of consecutive titanium oxide deposition cycles.
• the intermediate deposition phase can include, consist of, or consist essentially of, a combination of the above-described sequences of deposition cycles.
• the number and sequence of strontium oxide and titanium oxide deposition cycles in the intermediate deposition phase can be varied by one of skill in the art to result, for example, in a strontium titanate layer of the desired thickness and having a substantially 1 : 1 atomic ratio of strontium:titanium.
• the intermediate deposition phase can include multiple sets (e.g., from 4 to 20 or even more sets) of from 2 to 4 consecutive strontium oxide deposition cycles alternating with from 7 to 14 consecutive titanium oxide deposition cycles.
• the intermediate deposition phase begins with and ends with one or more strontium oxide deposition cycles.
• the term "or" is generally employed in the sense as including "and/or” unless the context of the usage clearly indicates otherwise.
• a final titanium oxide deposition phase can deposit a layer of titanium oxide 140 on intermediate deposition layer 130.
• titanium oxide layer 140 can at most 1 nanometer thick, and in other certain embodiments, at most 0.6 nanometer thick. In certain embodiments, titanium oxide layer 140 can be at least 0.3 nanometer thick.
• the final titanium oxide deposition phase includes a plurality of titanium oxide deposition cycles. In some embodiments, the final titanium oxide deposition phase consists of, or consists essentially of, a plurality of titanium oxide deposition cycles. For example, in certain embodiments, the final titanium oxide deposition phase can consist of from 11 to 14 titanium oxide deposition cycles.
• strontium titanate films characterized, for example, by substantially a 1 :1 strontium: titanium atomic ratio and/or a low carbon- containing impurity (e.g., SrCO 3 ) content, properties that can result, for example, in high dielectric constants.
• Strontium:titanium atomic ratios of from 0.9:1.0 to 1.0:0.9 are considered herein to be substantially 1 :1 strontium:titanium atomic ratios.
• the recitations of numerical ranges by endpoints include all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).
• Strontium titanates having low carbon-content, and in certain embodiments no detectable carbon-content can be advantageous for producing strontium titanate films having the desired crystalline perovskite (e.g., cubic) phase, as deposited and/or after annealing.
• Strontium titanate films with the desired crystalline perovskite phase can be advantageous for having high dielectric constants.
• Metal-containing precursor compositions can be used to form metal- containing layers in various methods as described in the present disclosure.
• metal-containing is used to refer to a material, typically a compound or a layer, that may consist entirely of a metal, or may include other elements in addition to a metal.
• Typical metal-containing compounds include, but are not limited to, metals, metal-ligand complexes, metal salts, organometallic compounds, and combinations thereof.
• Typical metal- containing layers include, but are not limited to, metals, metal oxides, metal silicates, and combinations thereof.
• Various metal-containing compounds can be used in various combinations, optionally with one or more organic solvents (particularly for CVD processes), to form a precursor composition. Some of the metal- containing compounds disclosed herein can be used in ALD without adding solvents.
• Precursor and “precursor composition” as used herein refer to a composition usable for forming, either alone or with other precursor compositions (or reactants), a layer on a substrate assembly in a deposition process. Further, one skilled in the art will recognize that the type and amount of precursor used will depend on the content of a layer which is ultimately to be formed using a vapor deposition process. In certain embodiments of the methods as described herein, the precursor compositions are liquid at the vaporization temperature, and sometimes liquid at room temperature.
• the precursor compositions may be liquids or solids at room temperature, and for certain embodiments are liquids at the vaporization temperature. Typically, they are liquids sufficiently volatile to be employed using known vapor deposition techniques. However, as solids they may also be sufficiently volatile that they can be vaporized or sublimed from the solid state using known vapor deposition techniques. If they are less volatile solids, they can be sufficiently soluble in an organic solvent or have melting points below their decomposition temperatures such that they can be used, for example, in flash vaporization, bubbling, microdroplet formation techniques, etc.
• vaporized metal-containing compounds may be used either alone or optionally with vaporized molecules of other metal-containing compounds or optionally with vaporized solvent molecules or inert gas molecules, if used.
• liquid refers to a solution or a neat liquid (a liquid at room temperature or a solid at room temperature that melts at an elevated temperature).
• solution does not require complete solubility of the solid but may allow for some undissolved solid, as long as there is a sufficient amount of the solid delivered by the organic solvent into the vapor phase for chemical vapor deposition processing. If solvent dilution is used in deposition, the total molar concentration of solvent vapor generated may also be considered as an inert carrier gas.
• inert gas or "non-reactive gas,” as used herein, is any gas that is generally unreactive with the components it comes in contact with.
• inert gases are typically selected from a group including nitrogen, argon, helium, neon, krypton, xenon, any other non-reactive gas, and mixtures thereof.
• Such inert gases are generally used in one or more purging processes as described herein, and in some embodiments may also be used to assist in precursor vapor transport.
• Solvents that are suitable for certain embodiments of methods as described herein may be one or more of the following: aliphatic hydrocarbons or unsaturated hydrocarbons (C3-C20, and in certain embodiments C5-C10, cyclic, branched, or linear), aromatic hydrocarbons (C5-C20, and in certain embodiments C5-C10), halogenated hydrocarbons, silylated hydrocarbons such as alkylsilanes, alkylsilicates, ethers, cyclic ethers (e.g., tetrahydrofuran, THF), polyethers, thioethers, esters, lactones, nitriles, silicone oils, or compounds containing combinations of any of the above or mixtures of one or more of the above.
• the compounds are also generally compatible with each other, so that mixtures of variable quantities of the metal-containing compounds will not interact to significantly change their physical properties.
• metal precursor compounds As used herein, a "metal precursor compound” is used to refer to a compound that can provide a source of the metal in an atomic layer deposition method. Further, in some embodiments, the methods include “metal-organic” precursor compounds.
• the term “metal-organic” is intended to be broadly interpreted as referring to a compound that includes in addition to a metal, an organic group (i.e., a carbon-containing group). Thus, the term “metal- organic” includes, but is not limited to, organometallic compounds, metal- ligand complexes, metal salts, and combinations thereof.
• Example metal-organic strontium precursor compounds include, but are not limited to, strontium ⁇ - diketonates, strontium ⁇ -diketiminates (e.g., bis(N,N'-diisopropyl-2,4- pentanediiminate)strontium), strontium amidinates (e.g., bis(N-dimethyl- N',N"-diisopropylguanidinate)strontium), strontium cyclopentadienyls (e.g., bis(triisopropylcyclopentadienyl)strontium), strontium diorganoamides (e.g., Sr[N(SiMe 3 ) 2 ] 2 ), strontium carboxylates, strontium alkoxides, and combinations thereof.
• strontium ⁇ - diketonates e.g., bis(N,N'-diisopropyl-2,4- pentan
• Strontium ⁇ -diketonates are defined herein as a strontium-containing compound including at least one ⁇ -diketonate ligand.
• a “an,” “the,” and “at least one” are used interchangeably and mean one or more than one.
• Example ⁇ -diketonate ligands include, for example, 2,2,6,6- tetramethyl-3,5-heptanedionate (thd), l-(2-methoxyethoxy)-2,2,6,6- tetramethyl-3,5-heptanedionate (methd), hexafluoroacetylacetonate, 1,1,1- trifluoro-2,4-pentanedionate, 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5- octanedionate (fod), and combinations thereof.
• Example metal-organic strontium ⁇ -diketonate precursor compounds include Sr(thd) 2 , Sr(methd) 2 , Sr(fod) 2 , and combinations thereof.
• the titanium precursor compound can be an inorganic precursor compound (e.g., titanium tetrachloride, TiCl 4 ).
• the titanium precursor compound can be a metal-organic precursor compound.
• Example metal-organic titanium precursor compounds include, but are not limited to, titanium alkoxides, titanium amides, titanium imides, titanium ⁇ -diketonates, and combinations thereof.
• Example metal-organic titanium precursor compounds include, but are not limited to, tetrakis(isopropoxy) titanium (Ti(OzPr) 4 ); tetrakis(diethylamido) titanium (Ti(NEt 2 ) 4 ); tetrakis(dimethylamido) titanium (Ti(NMe 2 ) 4 ; tetrakis(ethylmethylamido) titanium (Ti(NEtMe) 4 ); trichlorotitanium dialkylamides; and combinations thereof.
• Example metal-organic titanium precursor compounds also include, but are not limited to, titanium ⁇ -diketonates, which are defined herein as a titanium-containing compound including at least one ⁇ -diketonate ligand.
• Example ⁇ -diketonate ligands include, but are not limited to, 2,2,6,6- tetramethyl-3,5-heptanedionate (thd), 1 -(2-methoxyethoxy)-2,2,6,6- tetramethyl-3,5-heptanedionate (methd), hexafluoroacetylacetonate, 1,1,1- trifluoro-2,4-pentanedionate, 2,2-dimethyl-6,6,7,7,8,8,8-heptafluoro-3,5- octanedionate (fod), and combinations thereof.
• Another example metal-organic titanium precursor compound includes
• organic group is used for the purpose of this disclosure to mean a hydrocarbon group that is classified as an aliphatic group, cyclic group, or combination of aliphatic and cyclic groups (e.g., alkaryl and aralkyl groups).
• suitable organic groups for metal-containing compounds of this disclosure are those that do not interfere with the formation of a metal oxide layer using vapor deposition techniques.
• aliphatic group means a saturated or unsaturated linear or branched hydrocarbon group. This term is used to encompass alkyl, alkenyl, and alkynyl groups, for example.
• alkyl group means a saturated linear or branched monovalent hydrocarbon group including, for example, methyl, ethyl, ⁇ -propyl, isopropyl, tert-butyl, amyl, heptyl, and the like.
• alkenyl group means an unsaturated, linear or branched monovalent hydrocarbon group with one or more olef ⁇ nically unsaturated groups (i.e., carbon-carbon double bonds), such as a vinyl group.
• alkynyl group means an unsaturated, linear or branched monovalent hydrocarbon group with one or more carbon-carbon triple bonds.
• cyclic group means a closed ring hydrocarbon group that is classified as an alicyclic group, aromatic group, or heterocyclic group.
• alicyclic group means a cyclic hydrocarbon group having properties resembling those of aliphatic groups.
• aromatic group or “aryl group” means a mono- or polynuclear aromatic hydrocarbon group.
• heterocyclic group means a closed ring hydrocarbon in which one or more of the atoms in the ring is an element other than carbon (e.g., nitrogen, oxygen, sulfur, etc.).
• group and “moiety” are used to differentiate between chemical species that allow for substitution or that may be substituted and those that do not so allow for substitution or may not be so substituted.
• group when the term “group” is used to describe a chemical substituent, the described chemical material includes the unsubstituted group and that group with nonperoxidic O, N, S, Si, or F atoms, for example, in the chain as well as carbonyl groups or other conventional substituents.
• moiety is used to describe a chemical compound or substituent, only an unsubstituted chemical material is intended to be included.
• alkyl group is intended to include not only pure open chain saturated hydrocarbon alkyl substituents, such as methyl, ethyl, propyl, tert-butyl, and the like, but also alkyl substituents bearing further substituents known in the art, such as hydroxy, alkoxy, alkyl sulfonyl, halogen atoms, cyano, nitro, amino, carboxyl, etc.
• alkyl group includes ether groups, haloalkyls, nitroalkyls, carboxyalkyls, hydroxyalkyls, sulfoalkyls, etc.
• the phrase “alkyl moiety” is limited to the inclusion of only pure open chain saturated hydrocarbon alkyl substituents, such as methyl, ethyl, propyl, tert-butyl, and the like.
• Precursor compositions as described herein can, optionally, be vaporized and deposited/chemisorbed substantially simultaneously with, and in the presence of, one or more reaction gases.
• reaction gases can include, for example, nitrogen-containing sources (e.g., ammonia) and oxygen-containing sources, which can be oxidizing gases.
• nitrogen-containing sources e.g., ammonia
• oxygen-containing sources which can be oxidizing gases.
• suitable oxidizing gases can be used including, for example, air, oxygen, water vapor, ozone, nitrogen oxides (e.g., nitric oxide), hydrogen peroxide, alcohols (e.g., isopropanol), and combinations thereof.
• the metal-containing layer can be deposited, for example, on a substrate
• semiconductor substrate or substrate assembly
• a base semiconductor layer is typically the lowest layer of silicon material on a wafer or a silicon layer deposited on another material, such as silicon on sapphire.
• various process steps may have been previously used to form or define regions, junctions, various structures or features, and openings such as transistors, active areas, diffusions, implanted regions, vias, contact openings, high aspect ratio openings, capacitor plates, barriers for capacitors, etc.
• Layer refers to any layer that can be formed on a substrate from one or more precursors and/or reactants according to the deposition process described herein.
• layer is meant to include layers specific to the semiconductor industry, such as, but clearly not limited to, a barrier layer, dielectric layer (i.e., a layer having a high dielectric constant), and conductive layer.
• layer is synonymous with the term “film” frequently used in the semiconductor industry.
• layer is also meant to include layers found in technology outside of semiconductor technology, such as coatings on glass. For example, such layers can be formed directly on fibers, wires, etc., which are substrates other than semiconductor substrates. Further, the layers can be formed directly on the lowest semiconductor surface of the substrate, or they can be formed on any of a variety of layers (e.g., surfaces) as in, for example, a patterned wafer.
• Suitable substrate materials of the present disclosure include conductive materials, semiconductive materials, conductive metal-nitrides, conductive metals, conductive metal oxides, etc.
• the substrate on which the metal- containing layer is formed can be a semiconductor substrate or substrate assembly.
• semiconductor materials such as for example, borophosphosilicate glass (BPSG), silicon such as, e.g., conductively doped polysilicon, monocrystalline silicon, etc.
• BPSG borophosphosilicate glass
• silicon such as, e.g., conductively doped polysilicon, monocrystalline silicon, etc.
• silicon for example in the form of a silicon wafer, tetraethylorthosilicate (TEOS) oxide, spin on glass (i.e., a thin layer of SiO 2 , optionally doped, deposited by a spin on process), TiN, TaN, W, Ru, Al, Cu, noble metals, etc.
• TEOS tetraethylorthosilicate
• spin on glass i.e., a thin layer of SiO 2 , optionally doped, deposited by a spin on process
• a substrate assembly may also contain a layer that includes platinum, iridium, iridium oxide, rhodium, ruthenium, ruthenium oxide, strontium ruthenate, lanthanum nickelate, titanium nitride, tantalum nitride, tantalum-silicon- nitride, silicon dioxide, aluminum, gallium arsenide, glass, etc., and other existing or to-be-developed materials used in semiconductor constructions, such as dynamic random access memory (DRAM) devices, static random access memory (SRAM) devices, and ferroelectric memory (FERAM) devices, for example.
• DRAM dynamic random access memory
• SRAM static random access memory
• FERAM ferroelectric memory
• the layers can be formed directly on the lowest semiconductor surface of the substrate, or they can be formed on any of a variety of the layers (i.e., surfaces) as in a patterned wafer, for example.
• Substrates other than semiconductor substrates or substrate assemblies can also be used in presently disclosed methods. Any substrate that may advantageously form a metal-containing layer thereon, such as a metal oxide layer, may be used, such substrates including, for example, fibers, wires, etc.
• the precursor compositions can be vaporized in the presence of an inert carrier gas if desired.
• an inert carrier gas can be used in purging steps in an ALD process (discussed below).
• the inert carrier gas is typically one or more of nitrogen, helium, argon, etc.
• an inert carrier gas is one that does not interfere with the formation of the metal-containing layer. Whether done in the presence of a inert carrier gas or not, the vaporization can be done in the absence of oxygen to avoid oxygen contamination of the layer (e.g., oxidation of silicon to form silicon dioxide or oxidation of precursor in the vapor phase prior to entry into the deposition chamber).
• the terms "deposition process” and "vapor deposition process” as used herein refer to a process in which a metal-containing layer is formed on one or more surfaces of a substrate (e.g., a doped polysilicon wafer) from vaporized precursor composition(s) including one or more metal-containing compound(s). Specifically, one or more metal-containing compounds are vaporized and directed to and/or contacted with one or more surfaces of a substrate (e.g., semiconductor substrate or substrate assembly) placed in a deposition chamber. Typically, the substrate is heated. These metal- containing compounds can form (e.g., by reacting or decomposing) a nonvolatile, thin, uniform, metal-containing layer on the surface(s) of the substrate.
• the term "vapor deposition process” is meant to include both chemical vapor deposition processes (including pulsed chemical vapor deposition processes) and atomic layer deposition processes.
• ALD atomic layer deposition
• a precursor is chemisorbed to a deposition surface (e.g., a substrate assembly surface or a previously deposited underlying surface such as material from a previous ALD cycle), forming a monolayer or sub-monolayer that does not readily react with additional precursor (i.e., a self-limiting reaction).
• a reactant e.g., another precursor or reaction gas
• this reactant is capable of further reaction with the precursor.
• purging steps may also be utilized during each cycle to remove excess precursor from the process chamber and/or remove excess reactant and/or reaction byproducts from the process chamber after conversion of the chemisorbed precursor.
• atomic layer deposition is also meant to include processes designated by related terms such as, “chemical vapor atomic layer deposition,” “atomic layer epitaxy” (ALE) (see U.S. Patent No.
• MBE molecular beam epitaxy
• gas source MBE or organometallic MBE
• chemical beam epitaxy when performed with alternating pulses of precursor composition(s), reactive gas, and purge (e.g., inert carrier) gas.
• purge e.g., inert carrier
• the longer duration multi-cycle ALD process allows for improved control of layer thickness and composition by self-limiting layer growth, and minimizing detrimental gas phase reactions by separation of the reaction components.
• the self-limiting nature of ALD provides a method of depositing a film on a wide variety of reactive surfaces, including surfaces with irregular topographies, with better step coverage than is available with CVD or other "line of sight" deposition methods such as evaporation or physical vapor deposition (PVD or sputtering).
• atomic layer deposition methods as disclosed herein include a plurality of deposition phases such as, for example, an initial titanium oxide deposition phase, an intermediate deposition phase, and a final titanium oxide deposition phase.
• Each deposition phase includes a plurality of deposition cycles.
• a titanium oxide deposition phase (e.g., an initial titanium oxide deposition phase and/or a final titanium oxide deposition phase) includes a plurality of titanium oxide deposition cycles.
• each titanium oxide deposition cycle can include, for example, at least one titanium precursor dose, a first purge, at least one oxidizer dose, and a second purge.
• an intermediate deposition phase includes a plurality of strontium oxide deposition cycles and a plurality of titanium oxide deposition cycles (as described herein above).
• each strontium oxide deposition cycle can include, for example, at least one strontium precursor dose, a first purge, at least one oxidizer dose, and a second purge.
• Chemical vapor deposition (CVD) and atomic layer deposition (ALD) are two vapor deposition processes often employed to form thin, continuous, uniform, metal-containing layers onto semiconductor substrates.
• CVD chemical vapor deposition
• ALD atomic layer deposition
• vapor deposition process typically one or more precursor compositions are vaporized in a deposition chamber and optionally combined with one or more reaction gases and directed to and/or contacted with the substrate to form a metal-containing layer on the substrate.
• the vapor deposition process may be enhanced by employing various related techniques such as plasma assistance, photo assistance, laser assistance, as well as other techniques.
• a typical CVD process may be carried out in a chemical vapor deposition reactor, such as a deposition chamber available under the trade designation of 7000 from Genus, Inc. (Sunnyvale, CA), a deposition chamber available under the trade designation of 5000 from Applied Materials, Inc. (Santa Clara, CA), or a deposition chamber available under the trade designation of Prism from Novelus, Inc. (San Jose, CA).
• a chemical vapor deposition reactor such as a deposition chamber available under the trade designation of 7000 from Genus, Inc. (Sunnyvale, CA), a deposition chamber available under the trade designation of 5000 from Applied Materials, Inc. (Santa Clara, CA), or a deposition chamber available under the trade designation of Prism from Novelus, Inc. (San Jose, CA).
• any deposition chamber suitable for performing CVD may be used.
• the vapor deposition process employed in the methods of the present disclosure can be a multi-cycle atomic layer deposition (ALD) process.
• ALD atomic layer deposition
• Such a process is advantageous, in particular advantageous over a CVD process, in that it provides for improved control of atomic-level thickness and uniformity to the deposited layer (e.g., dielectric layer) by providing a plurality of self-limiting deposition cycles.
• the self-limiting nature of ALD provides a method of depositing a film on a wide variety of reactive surfaces including, for example, surfaces with irregular topographies, with better step coverage than is available with CVD or other "line of sight" deposition methods (e.g., evaporation and physical vapor deposition, i.e., PVD or sputtering).
• ALD processes typically expose the metal-containing compounds to lower volatilization and reaction temperatures, which tends to decrease degradation of the precursor as compared to, for example, typical CVD processes.
• each reactant is pulsed onto a suitable substrate, typically at deposition temperatures of at least 25°C, in certain embodiments at least 15O 0 C, and in other embodiments at least 200 0 C.
• Typical ALD deposition temperatures are no greater than 400 0 C, in certain embodiments no greater than 350 0 C, and in other embodiments no greater than 250 0 C. These temperatures are generally lower than those presently used in CVD processes, which typically include deposition temperatures at the substrate surface of at least 150 0 C, in some embodiments at least 200 0 C, and in other embodiments at least 250 0 C.
• Typical CVD deposition temperatures are no greater than 600 0 C, in certain embodiments no greater than 500 0 C, and in other embodiments no greater than 400 0 C.
• a typical ALD process includes exposing a substrate (which may optionally be pretreated with, for example, water and/or ozone) to a first chemical to accomplish chemisorption of the species onto the substrate.
• chemisorption refers to the chemical adsorption of vaporized reactive metal-containing compounds on the surface of a substrate.
• the adsorbed species are typically irreversibly bound to the substrate surface as a result of relatively strong binding forces characterized by high adsorption energies (e.g., >30 kcal/mol), comparable in strength to ordinary chemical bonds.
• the chemisorbed species typically form a monolayer on the substrate surface.
• ALD atomic layer deposition deposition deposition deposition deposition deposition deposition chamber chemisorbed onto the surfaces of a substrate.
• a reactive compound e.g., one or more precursor compositions and one or more reaction gases
• ALD can alternately utilize one precursor composition, which is chemisorbed, and one reaction gas, which reacts with the chemisorbed species.
• chemisorption might not occur on all portions of the deposition surface (e.g., previously deposited ALD material). Nevertheless, such imperfect monolayer is still considered a monolayer in the context of the present disclosure. In many applications, merely a substantially saturated monolayer may be suitable. In one aspect, a substantially saturated monolayer is one that will still yield a deposited monolayer or less of material exhibiting the desired quality and/or properties. In another aspect, a substantially saturated monolayer is one that is self-limited to further reaction with precursor.
• a typical ALD process includes exposing an initial substrate to a first chemical species A (e.g., a metal-containing compound as described herein) to accomplish chemisorption of the species onto the substrate.
• Species A can react either with the substrate surface or with Species B (described below), but not with itself.
• a first chemical species A e.g., a metal-containing compound as described herein
• Species A can react either with the substrate surface or with Species B (described below), but not with itself.
• Species A can react either with the substrate surface or with Species B (described below), but not with itself.
• Species A can react either with the substrate surface or with Species B (described below), but not with itself.
• Species B described below
• one or more of the ligands of Species A is displaced by reactive groups on the substrate surface.
• the chemisorption forms a monolayer that is uniformly one atom or molecule thick on the entire exposed initial substrate, the
• chemisorption may not occur on all portions of the substrate. Nevertheless, such a partial monolayer is still understood to be a monolayer in the context of the present disclosure. In many applications, merely a substantially saturated monolayer may be suitable. A substantially saturated monolayer is one that will still yield a deposited layer exhibiting the quality and/or properties desired for such layer.
• the first species e.g., substantially all non-chemisorbed molecules of
• Species A) as well as displaced ligands are purged from over the substrate and a second chemical species, Species B (e.g., a different metal-containing compound or reactant gas) is provided to react with the monolayer of Species A.
• Species B typically displaces the remaining ligands from the Species A monolayer and thereby is chemisorbed and forms a second monolayer. This second monolayer displays a surface which is reactive only to Species A.
• Non-chemisorbed Species B, as well as displaced ligands and other byproducts of the reaction are then purged and the steps are repeated with exposure of the Species B monolayer to vaporized Species A.
• the second species can react with the first species, but not chemisorb additional material thereto. That is, the second species can cleave some portion of the chemisorbed first species, altering such monolayer without forming another monolayer thereon, but leaving reactive sites available for formation of subsequent monolayers.
• a third species or more may be successively chemisorbed (or reacted) and purged just as described for the first and second species, with the understanding that each introduced species reacts with the monolayer produced immediately prior to its introduction.
• the second species (or third or subsequent) can include at least one reaction gas if desired.
• the use of ALD provides the ability to improve the control of thickness, composition, and uniformity of metal-containing layers on a substrate. For example, depositing thin layers of metal-containing compound in a plurality of cycles provides a more accurate control of ultimate film thickness. This is particularly advantageous when the precursor composition is directed to the substrate and allowed to chemisorb thereon, optionally further including at least one reaction gas that can react with the chemisorbed species on the substrate, and in certain embodiments wherein this cycle is repeated at least once.
• Purging of excess vapor of each species following deposition/chemisorption onto a substrate may involve a variety of techniques including, but not limited to, contacting the substrate and/or monolayer with an inert carrier gas and/or lowering pressure to below the deposition pressure to reduce the concentration of a species contacting the substrate and/or chemisorbed species.
• carrier gases as discussed above, may include N 2 , Ar, He, etc.
• purging may instead include contacting the substrate and/or monolayer with any substance that allows chemisorption by-products to desorb and reduces the concentration of a contacting species preparatory to introducing another species.
• the contacting species may be reduced to some suitable concentration or partial pressure known to those skilled in the art based on the specifications for the product of a particular deposition process.
• ALD is often described as a self-limiting process, in that a finite number of sites exist on a substrate to which the first species may form chemical bonds.
• the second species might only react with the surface created from the chemisorption of the first species and thus, may also be self-limiting.
• process conditions can be varied in ALD to promote such bonding and render ALD not self-limiting, e.g., more like pulsed CVD.
• ALD may also encompass a species forming other than one monolayer at a time by stacking of a species, forming a layer more than one atom or molecule thick.
• the described method indicates the "substantial absence" of the second precursor (i.e., second species) during chemisorption of the first precursor since insignificant amounts of the second precursor might be present. According to the knowledge of one of ordinary skill in the art, a determination can be made as to the tolerable amount of second precursor and process conditions selected to achieve the substantial absence of the second precursor.
• the layer deposition is accomplished by alternately introducing (i.e., by pulsing) precursor composition(s) into the deposition chamber containing a substrate, chemisorbing the precursor composition(s) as a monolayer onto the substrate surfaces, purging the deposition chamber, then introducing to the chemisorbed precursor composition(s) reaction gases and/or other precursor composition(s) in a plurality of deposition cycles until the desired thickness of the metal-containing layer is achieved.
• the pulse duration of precursor composition(s) and inert carrier gas(es) is generally of a duration sufficient to saturate the substrate surface.
• the pulse duration is at least 0.1 seconds, in certain embodiments at least 0.2 second, and in other embodiments at least 0.5 second.
• pulse durations are generally no greater than 2 minutes, and in certain embodiments no greater than 1 minute.
• ALD is predominantly chemically driven.
• ALD may advantageously be conducted at much lower temperatures than CVD.
• the substrate temperature may be maintained at a temperature sufficiently low to maintain intact bonds between the chemisorbed precursor composition(s) and the underlying substrate surface and to prevent decomposition of the precursor composition(s).
• the temperature on the other hand, must be sufficiently high to avoid condensation of the precursor composition(s).
• the substrate is kept at a temperature of at least 25 0 C, in certain embodiments at least 150°C, and in other certain embodiments at least 200 0 C.
• the substrate is kept at a temperature of no greater than 400 0 C, in certain embodiments no greater than 350 0 C, and in other certain embodiments no greater than 300 0 C, which, as discussed above, is generally lower than temperatures presently used in typical CVD processes.
• the first species or precursor composition is chemisorbed at this temperature.
• Surface reaction of the second species or precursor composition can occur at substantially the same temperature as chemisorption of the first precursor or, optionally, at a substantially different temperature.
• some small variation in temperature as judged by those of ordinary skill, can occur but still be considered substantially the same temperature by providing a reaction rate statistically the same as would occur at the temperature of the first precursor chemisorption.
• chemisorption and subsequent reactions could instead occur at substantially exactly the same temperature.
• the pressure inside the deposition chamber can be at least 10 " torr (1.3 x 10 " Pascal, "Pa"), in certain embodiments at least 10 "7 torr (1.3 x 10 "s Pa), and in other certain embodiments at least 10 "6 torr (1.3 x 10 "4 Pa).
• deposition pressures are typically no greater than 10 torr (1.3 x 10 3 Pa), in certain embodiments no greater than 5 torr (6.7 x 10 2 Pa), and in other certain embodiments no greater than 2 torr (2.7 x 10 Pa).
• the deposition chamber is purged with an inert carrier gas after the vaporized precursor composition(s) have been introduced into the chamber and/or reacted for each cycle.
• the inert carrier gas/gases can also be introduced with the vaporized precursor composition(s) during each cycle.
• the reactivity of a precursor composition can significantly influence the process parameters in ALD. Under typical CVD process conditions, a highly reactive compound may react in the gas phase generating particulates, depositing prematurely on undesired surfaces, producing poor films, and/or yielding poor step coverage or otherwise yielding non-uniform deposition. For at least such reason, a highly reactive compound might be considered not suitable for CVD. However, some compounds not suitable for CVD are superior ALD precursors. For example, if the first precursor is gas phase reactive with the second precursor, such a combination of compounds might not be suitable for CVD, although they could be used in ALD. In the CVD context, concern might also exist regarding sticking coefficients and surface mobility, as known to those skilled in the art, when using highly gas-phase reactive precursors, however, little or no such concern would exist in the ALD context.
• an annealing process may be optionally performed in situ in the deposition chamber in a reducing, inert, plasma, or oxidizing atmosphere.
• the annealing temperature can be at least 400 0 C, in some embodiments at least 500 0 C, and in some other embodiments at least 600 0 C.
• the annealing temperature is typically no greater than 1000 0 C, in some embodiments no greater than 750 0 C, and in some other embodiments no greater than 700 0 C.
• the annealing operation is typically performed for a time period of at least 0.5 minute, and in certain embodiments for a time period of at least 1 minute. Additionally, the annealing operation is typically performed for a time period of no greater than 60 minutes, and in certain embodiments for a time period of no greater than 10 minutes.
• temperatures and time periods may vary.
• furnace anneals and rapid thermal annealing may be used, and further, such anneals may be performed in one or more annealing steps.
• anneals may be performed in one or more annealing steps.
• the use of the compounds and methods of forming films of the present disclosure are beneficial for a wide variety of thin film applications in semiconductor structures, particularly those using high dielectric permittivity materials.
• such applications include gate dielectrics and capacitors such as planar cells, trench cells (e.g., double sidewall trench capacitors), stacked cells (e.g., crown, V-cell, delta cell, multi-fingered, or cylindrical container stacked capacitors), as well as field effect transistor devices.
• FIG. 2 An example system that can be used to perform an atomic layer deposition method as described herein is shown in Figure 2.
• the system illustrated in Figure 2 is representative of a single wafer tool having a single wafer chamber.
• the system illustrated in Figure 2 includes an enclosed vapor deposition chamber 10, in which a vacuum may be created using turbo pump 12 and backing pump 14.
• One or more substrates 16 e.g., semiconductor substrates or substrate assemblies
• a constant nominal temperature can be established for substrate 16, which can vary depending on the process used.
• Substrate 16 may be heated, for example, by an electrical resistance heater 18 on which substrate 16 can be mounted. Other known methods of heating the substrate may also be utilized.
• titanium precursor composition(s) 30 and strontium precursor composition(s) 31 can be stored in vessels 20 and 21, respectively.
• Vessel 22 can be used to store optional solvent 32.
• the precursor composition(s) 30 and 31 and optional solvent 32 can be maintained under an inert atmosphere supplied by inert gas 40 by actuating valves 80, 82, 84, and 86 as desired.
• Optional inert carrier gas 42 (which can be the same as or different than inert gas 40), titanium precursor composition(s) 30, strontium precursor composition(s) 31, and/or optional solvent 32 can independently be delivered to optional manifold 50, optional vaporizer 60, and deposition chamber 10 by actuating valves 81, 83, 85, 87, and 88 as desired.
• reaction gas 44 can be supplied along line 72 as desired by actuating valve 89.
• Optional gas 46 e.g., a purge gas, which can be the same as or different than inert gas 40 and/or inert carrier gas 42
• actuating valve 90 can be supplied along line 74 as desired by actuating valve 90.
• FIG. 3 shows an example of the ALD formation of metal-containing layers of the present disclosure as used in an example capacitor construction.
• capacitor construction 200 includes substrate 210 having conductive diffusion area 215 formed therein.
• Substrate 210 can include, for example, silicon.
• An insulating layer 260 such as BPSG, is provided over substrate 210, with contact opening 280 provided therein to diffusion area 215.
• Conductive material 290 fills contact opening 280, and may include, for example, tungsten or conductively doped polysilicon.
• Capacitor construction 200 includes a first capacitor electrode (a bottom electrode) 220, a dielectric layer 240 which may be formed by methods as described herein, and a second capacitor electrode (a top electrode) 250.
• Figure 3 is an example construction, and methods as described herein can be useful for forming layers on any substrate, for example on semiconductor structures, and that such applications include capacitors such as planar cells, trench cells, (e.g., double sidewall trench capacitors), stacked cells (e.g., crown, V-cell, delta cell, multi-fingered, or cylindrical container stacked capacitors), as well as field effect transistor devices.
• capacitors such as planar cells, trench cells, (e.g., double sidewall trench capacitors), stacked cells (e.g., crown, V-cell, delta cell, multi-fingered, or cylindrical container stacked capacitors), as well as field effect transistor devices.
• a diffusion barrier layer may optionally be formed over the dielectric layer 240, and may, for example, include TiN, TaN, metal suicide, or metal silicide-nitride. While the diffusion barrier layer is described as a distinct layer, it is to be understood that the barrier layers may include conductive materials and can accordingly, in such embodiments, be understood to include at least a portion of the capacitor electrodes. In certain embodiments that include a diffusion barrier layer, an entirety of a capacitor electrode can include conductive barrier layer materials.
• EXAMPLE 1 A strontium titanate layer was deposited on a platinum substrate by ALD using Sr(thd) 2 as a metal-organic strontium precursor compound, Ti(mpd)(thd) 2 as a titanium precursor compound, and ozone as a reaction gas.
• the titanium precursor flow rate was 0.8 milliliters (ml) per minute; the strontium precursor flow rate was 0.8 ml per minute; and the ozone flow rate was 3 standard liters per minute (slm) using 15% by volume ozone.
• the lines were flushed with tetrahydrofuran at a flow rate of from 0.4 to 1 ml per minute for 15 to 30 seconds after each titanium oxide and strontium oxide deposition cycle.
• the deposition was carried out using a vaporizer temperature of 290 0 C, a process temperature of from 1 to 2 Torr (from 1.3 x 10 2 to 2.6 x 10 2 Pa), and a substrate temperature of from 300 0 C to 350 0 C.
• Pumping was conducted using a turbo pump to pump down to a base of 20 mTorr (2.7 Pa).
• Each titanium oxide deposition cycle consisted of a 60 second titanium precursor dose, a 30 second purge, a 30 second oxidizer dose, and a 20 second purge.
• Each strontium oxide deposition cycle consisted of a 30 second strontium precursor dose, a 30 second purge, a 30 second ozone dose, and a 30 second purge.
• the strontium titanate layer was deposited using 11 titanium oxide deposition cycles for the initial titanium oxide deposition phase.
• the intermediate deposition phase consisted of 3 strontium oxide deposition cycles, followed by 20 sets of, in order, 11 titanium oxide deposition cycles and 3 strontium oxide deposition cycles. Finally, 1 1 titanium oxide deposition cycles were used for the final titanium oxide deposition phase.
• the deposited layer was rapid thermal process (RTP) annealed for 5 minutes at 600 0 C, resulting in an approximately 35 to 40 nanometers thick strontium titanate layer.
• RTP rapid thermal process
• XPS X-ray photoelectron spectrum
• X-ray diffraction (XRD) data was also gathered for strontium titanate prepared as described in Example 1 , and the data was compared to that for strontium titanate prepared in a similar manner, but without the initial and final titanium oxide deposition phases (i.e., Comparative Example 1).
• a strontium carbonate peak (SrCO 3 ) is indicated in the data presented in Figure 5a, which is a plot of intensity (arbitrary units or A. U.; y-axis) versus 2 theta (degrees; x-axis) measured for material at the top, center (ctr), and bottom (btm) of the furnace, for Comparative Example 1.
• FIG. 6 is an illustration of an oxygen multiplex graph, and shows a peak for strontium titanate (labeled "STO") in both scan 1 (Comparative Example 1) and scan 2 (Example 1).
• STO strontium titanate
• the peak for carbonate and adventitious surface carbon (labeled "carbonate”) is substantially smaller for scan 2 (Example 1) than for scan 1 (Comparative Example 1).
• Figure 6b is an illustration of a carbon multiplex graph. Again, the peak for carbonate and adventitious surface carbon (labeled "carbonate”) is substantially smaller for scan 2 (Example 1) than for scan 1 (Comparative Example 1).
• Some embodiments of the methods described herein can form a metal- containing layer on a substrate (e.g., a semiconductor substrate or substrate assembly).
• the method can include: providing a vapor including at least one titanium precursor compound; providing a vapor including at least one metal-organic strontium precursor compound; optionally providing a reaction gas (e.g., an oxidizing gas); and contacting the vapor including the at least one titanium precursor compound, the vapor including the at least one strontium precursor compound, and optionally the reaction gas with a substrate to form a metal-containing layer on at least one surface of the substrate using an atomic layer deposition process including a plurality of deposition cycles.
• a reaction gas e.g., an oxidizing gas
• the plurality of deposition cycles includes an initial titanium oxide deposition phase including at least one titanium oxide deposition cycle. In other certain embodiments, the plurality of deposition cycles includes a final titanium oxide deposition phase including at least one titanium oxide deposition cycle. In still other certain embodiments, the plurality of deposition cycles includes both an initial titanium oxide deposition phase and a final titanium oxide deposition phase, both phases including at least one titanium oxide deposition cycle. In certain embodiments, the plurality of deposition cycles further includes an intermediate deposition phase that includes a plurality of strontium oxide deposition cycles and a plurality of titanium oxide deposition cycles.
• the method can further include annealing the metal-containing layer to form, for example, a strontium titanate layer (e.g., a dielectric layer).
• a strontium titanate layer e.g., a dielectric layer
• the strontium titanate layer can have low carbon content (e.g., a low strontium carbonate content).
• Some other embodiments of methods as described herein can be used to manufacture a semiconductor structure.
• the method can include: providing a vapor including at least one titanium precursor compound; providing a vapor including at least one metal-organic strontium precursor compound; directing the vapor including the at least one titanium precursor compound to an atomic layer deposition chamber containing a semiconductor substrate or substrate assembly and allowing the at least one titanium precursor compound to chemisorb to at least one surface of the semiconductor substrate assembly; and directing the -vapor including the at least one strontium precursor compound to the atomic layer deposition chamber and allowing the at least one strontium precursor compound to chemisorb to at least one surface of the semiconductor substrate assembly to form a metal- containing layer on at least one surface of the semiconductor substrate or substrate assembly using an atomic layer deposition process including a plurality of deposition cycles.
• the plurality of deposition cycles can include an initial titanium oxide deposition phase including at least one titanium oxide deposition cycle and/or a final titanium oxide deposition phase including at least one titanium oxide
• Certain other embodiments of methods as described herein can be used to manufacture a memory device.
• the method can include: providing a vapor including at least one titanium precursor compound; providing a vapor including at least one metal-organic strontium precursor compound; optionally providing at least one reaction gas; and contacting the vapor including the at least one titanium precursor compound and the vapor including the at least one strontium precursor compound with a substrate having a first electrode thereon to form a dielectric layer on at least a portion of the first electrode of the substrate using an atomic layer deposition process including a plurality of deposition cycles.
• the plurality of deposition cycles can include an initial titanium oxide deposition phase including at least one titanium oxide deposition cycle, and/or a final titanium oxide deposition phase including at least one titanium oxide deposition cycle.
• the method can further include forming a second electrode on the dielectric layer.

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