Selective deposition on silicon-containing surfaces

Abstract

A method for selectively passivating a substrate surface, wherein the substrate surface comprises at least a first surface comprising silicon nitride and at least a second surface comprising a material other than silicon nitride. The method comprises exposing the surface to at least one organic isocyanate, wherein the organic isocyanate selectively reacts with the silicon nitride to passivate the first surface, thereby leaving the second surface substantially unreacted.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 62 / 723,023, filed on August 27, 2018, and U.S. Patent Application No. 16 / 548,983, filed on August 23, 2019, the disclosures of which are incorporated herein by reference in their entireties. Background Art

[0003] The present application relates to selective deposition on a first surface relative to a second surface of a substrate. Additionally, further processing can be used to subsequently deposit a different material on the second surface relative to the first surface.

[0004] Selective deposition processes have gained significant momentum, primarily due to the limitations of modern photolithography processes in enabling the fabrication of advanced semiconductor devices based on ever-shrinking physical dimensions. Traditionally, patterning in the microelectronics industry has been accomplished using various photolithography and etching processes. However, as photolithography has become exponentially more complex and expensive, the use of selective deposition to form self-aligned features is becoming far more attractive. The fabrication of self-aligned via structures significantly benefits from manufacturable selective deposition processes. Another potential application of selective deposition is gap filling. In gap filling, a dielectric "filler" film is selectively grown from the bottom of the trench toward the top. Selective deposition can be used for other applications, such as selective sidewall deposition, in which a film is selectively deposited on the exposed surfaces of three-dimensional Fin-FET structures. This would enable the deposition of sidewall spacers without the need for complex patterning steps. Selective deposition processes for metal and metal oxide films used as gate dielectrics and capacitor dielectrics also have significant applications in semiconductor device manufacturing.

[0005] There are numerous prior examples in the technical literature relating to the selective formation of surface passivation coatings on wafers having multiple exposed surfaces of varying chemistry. The goal is to retard or prevent film deposition by an ALD process on these passivated surfaces, without preventing deposition on surfaces where an ALD deposition process is required for film deposition. Typically, the selectivity of such processes is insufficient due to incomplete passivation of the surface and / or due to physical adsorption of ALD precursor molecules and subsequent formation of ALD film material within the passivation layer itself or on surfaces where deposition is undesirable. The present invention seeks to overcome the limitations of the prior art and provide an improved method for selectively depositing thin film materials using an ALD deposition process.

[0006] Liu, L.-H. et al., J. Phys.: Condens. Matter 28 (2016) 094014 (doi: 10.1088 / 0953-8984 / 28 / 9 / 094014) teach that silicon nitride can be selectively passivated to some extent relative to silicon oxide by treating the treated surface with an aldehyde-containing solution. Summary of the Invention

[0007] In one aspect, the present invention provides a method for selectively passivating a substrate surface by a gas phase reaction, wherein the substrate surface comprises at least a first surface comprising silicon nitride and at least a second surface comprising a material other than silicon nitride, the method comprising the steps of: a. contacting the substrate surface with a wet chemical composition; b. rinsing the surface with deionized water; c. drying the surface; d. optionally, treating the surface with a hydrogen plasma or an ammonia plasma; and e. exposing the surface to a vapor comprising at least one organic isocyanate having the structure of formula I: RN=C=O(I), wherein R is selected from H, substituted or unsubstituted C1 to C 18 Straight chain alkyl, substituted or unsubstituted branched C3 to C 18 Alkyl, substituted or unsubstituted C3 to C8 cycloalkyl, substituted or unsubstituted C3 to C 10 Heterocyclic group, substituted or unsubstituted C3 to C 18 Alkenyl, substituted or unsubstituted C4 to C 18 Aryl, substituted or unsubstituted C5 to C 20 Arylalkyl and substituted or unsubstituted C3 to C 10 Alkynyl groups, wherein the at least one organic isocyanate selectively reacts with the silicon nitride to passivate the first surface, thereby leaving the second surface substantially unreacted.

[0008] In another aspect, a method for selectively depositing a film on a substrate surface is provided, wherein the substrate surface comprises at least a first surface comprising silicon nitride and at least a second surface comprising a material other than silicon nitride, the method comprising the following steps: a. contacting the substrate surface with a wet chemical composition; b. rinsing the surface with deionized water; c. drying the surface; d. optionally, treating the surface with a hydrogen plasma or an ammonia plasma; e. exposing the surface to a vapor comprising at least one organic isocyanate having the structure of formula I: RN=C=O(I), wherein R is selected from H, substituted or unsubstituted C1 to C 18 Straight chain alkyl, substituted or unsubstituted branched C3 to C 18 Alkyl, substituted or unsubstituted C3 to C8 cycloalkyl, substituted or unsubstituted C3 to C 10 Heterocyclic group, substituted or unsubstituted C3 to C 18 Alkenyl, substituted or unsubstituted C4 to C 18 Aryl, substituted or unsubstituted C5 to C20 Arylalkyl and substituted or unsubstituted C3 to C 10 alkynyl groups, wherein at least one organic isocyanate selectively reacts with the silicon nitride to passivate the first surface, thereby leaving the second surface substantially unreacted; and f. exposing the substrate surface to one or more deposition precursors to selectively deposit a film on the second surface relative to the first surface.

[0009] The embodiments of the present invention may be used alone or in combination with each other. DETAILED DESCRIPTION

[0010] All references (including publications, patent applications, and patents) cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0011] The use of the terms "a" and "an" and "the" and similar designations in the context of describing the present invention (particularly in the context of the following claims) should be interpreted as covering both the singular and the plural, unless otherwise stated herein or the context clearly contradicts. Unless otherwise stated, the terms "comprise", "have", "include" and "contain" should be interpreted as open-ended terms (i.e., referring to "including but not limited to"). Unless otherwise indicated in this specification, the enumeration of numerical ranges in this specification is intended only to be used as a shorthand method for individually referring to each individual numerical value falling within the range, and each individual numerical value is incorporated into this specification as if it were individually enumerated in this specification. Unless otherwise stated herein or the context clearly contradicts, all methods described herein can be performed in any appropriate order. Unless otherwise stated, the use of any and all examples or exemplary language provided in this application (e.g., "such as") is only intended to better illustrate the present invention and does not limit the scope of the present invention. Any language in the specification should not be interpreted as indicating that any unclaimed element is necessary for implementing the present invention.

[0012] Preferred embodiments of the present invention are described herein, including the best mode known to the inventor for implementing the present invention. After reading the foregoing description, variations of these preferred embodiments may become clear to those of ordinary skill in the art. The inventors expect that a skilled person will adopt these variations when appropriate, and the inventors intend that the present invention be implemented in a manner different from that specifically described herein. Therefore, the present invention includes all modifications and equivalents of the subject matter described in the appended claims herein as permitted by applicable law. In addition, the present invention includes any combination of the above-mentioned elements in all possible variations thereof, unless otherwise stated herein or clearly contradicted by the context.

[0013] There are a variety of methods for selective deposition. Embodiments of the present disclosure relate to methods for using surface deactivation by exploiting the surface chemistry of two different surfaces. Since the two different surfaces have different reactive handles, this difference can be exploited by employing molecules that react with one surface (to deactivate it) but not the other.

[0014] In one embodiment, a method for selectively passivating a substrate surface by a vapor phase reaction is provided, wherein the substrate surface comprises at least a first surface comprising silicon nitride and at least a second surface comprising a material other than silicon nitride, the method comprising the steps of: a. contacting the substrate surface with a wet chemical composition; b. rinsing the surface with deionized water; c. drying the surface; d. optionally, treating the surface with a hydrogen plasma or an ammonia plasma; and e. exposing the surface to a vapor comprising at least one organic isocyanate having the structure of formula I: RN=C=O(I), wherein R is selected from H, substituted or unsubstituted C1 to C 18 Straight chain alkyl, substituted or unsubstituted branched C3 to C 18 Alkyl, substituted or unsubstituted C3 to C8 cycloalkyl, substituted or unsubstituted C3 to C 10 Heterocyclic group, substituted or unsubstituted C3 to C 18 Alkenyl, substituted or unsubstituted C4 to C 18 Aryl, substituted or unsubstituted C5 to C 20 Arylalkyl and substituted or unsubstituted C3 to C 10 Alkynyl groups, wherein at least one organic isocyanate selectively reacts with the silicon nitride to passivate the first surface, thereby leaving the second surface substantially unreacted.

[0015] In another embodiment, a method for selectively depositing a film on a substrate surface is provided, wherein the substrate surface includes at least a first surface comprising silicon nitride and at least a second surface comprising a material other than silicon nitride, the method comprising the following steps: a. contacting the substrate surface with a wet chemical composition; b. rinsing the surface with deionized water; c. drying the surface; d. optionally, treating the surface with a hydrogen plasma or an ammonia plasma; e. exposing the surface to a vapor comprising at least one organic isocyanate having the structure of formula I: RN=C=O(I), wherein R is selected from H, substituted or unsubstituted C1 to C 18 Straight chain alkyl, substituted or unsubstituted branched C3 to C 18 Alkyl, substituted or unsubstituted C3 to C8 cycloalkyl, substituted or unsubstituted C3 to C 10 Heterocyclic group, substituted or unsubstituted C3 to C 18 Alkenyl, substituted or unsubstituted C4 to C 18Aryl, substituted or unsubstituted C5 to C 20 Arylalkyl and substituted or unsubstituted C3 to C 10 alkynyl groups, wherein at least one organic isocyanate selectively reacts with the silicon nitride to passivate the first surface, thereby leaving the second surface substantially unreacted; and f. exposing the substrate to one or more deposition precursors to deposit a film selectively on the second surface relative to the first surface.

[0016] As used in this specification and the appended claims, the terms "substrate" and "wafer" are used interchangeably to refer to a surface or portion of a surface upon which a process is performed. Those skilled in the art will also understand that reference to a substrate may also refer to only a portion of a substrate, unless the context clearly indicates otherwise. Additionally, reference to depositing on a substrate may refer to both a bare substrate and a substrate having one or more films or features deposited or formed thereon.

[0017] As used herein, "substrate" refers to any substrate or material surface formed on a substrate on which film processing is performed during the manufacturing process. For example, substrate surfaces that may be processed include materials such as silicon, silicon oxide, strained silicon, silicon on insulator (SOI), carbon-doped silicon oxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials, depending on the application. Substrates include, but are not limited to, semiconductor wafers. Substrates may be exposed to pretreatment processes to polish, etch, reduce, oxidize, hydroxylate, anneal, and / or bake the substrate surface. In addition to film processing directly on the surface of the substrate itself, in this disclosure, any film processing step disclosed may also be performed on an underlying layer formed on the substrate, as disclosed in more detail below, and the term "substrate surface" is intended to include such underlying layers, as indicated by the context. Thus, for example, in the case where a film / layer or portion of a film / layer is deposited on a substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface. What is included in a given substrate surface will depend on what film is being deposited and the specific chemistry used. In one or more embodiments, the first substrate surface comprises a metal, and the second substrate surface comprises a dielectric, or vice versa. In some embodiments, the substrate surfaces may comprise certain functional groups (eg, -OH, -NH, etc.).

[0018] Likewise, the films that can be used in the methods described herein vary considerably. In some embodiments, the film can comprise or consist essentially of a metal. Examples of metal films include, but are not limited to, cobalt (Co), copper (Cu), nickel (Ni), tungsten (W), and the like. In some embodiments, the film comprises a dielectric. Examples include SiO2, SiN, HfO2, and the like.

[0019] In an embodiment of the present invention, the substrate has at least two discrete surfaces, wherein each discrete surface is characterized by a different chemical property. For example, in one embodiment, the surface of the substrate includes at least a first surface comprising silicon nitride and at least a second surface comprising a material other than silicon nitride.

[0020] The at least one second surface comprising a material other than silicon nitride can be, for example, any material selected from silicon dioxide, a metal oxide, copper, cobalt, tungsten, amorphous silicon, polycrystalline silicon, single crystal silicon, germanium, and amorphous germanium hydride. In some embodiments, the at least one second surface comprising silicon dioxide is a dielectric surface, such as a silicon dioxide surface. In some embodiments, the surface comprising silicon dioxide may comprise silicon oxide, fluorinated silica glass (FSG), carbon-doped silicon oxide (SiOC), and / or a material comprising more than about 50% silicon oxide. In some embodiments, the surface comprising silicon dioxide comprises -OH groups and may also include, for example, an aluminum oxide (Al2O3) surface having -OH surface groups.

[0021] Embodiments of the present disclosure provide methods for selectively depositing a film (e.g., a metal film) on one surface of a substrate relative to a second surface of the same substrate. As used in this specification and the appended claims, the term "selectively depositing a film on one surface relative to another surface" and the like refer to that one of the first or second surfaces is passivated to substantially prevent deposition on the passivation layer, and the film is deposited on the second (non-passivated) surface. The term "over" as used in this context does not mean the physical orientation of one surface on top of another surface, but rather a relationship to the thermodynamic or kinetic properties of the chemical reaction of one surface relative to the other surface. For example, selectively depositing a cobalt film on a copper surface relative to a dielectric surface means that the cobalt film is deposited on the copper surface while less or no cobalt film is deposited on the dielectric surface; or that the formation of the cobalt film on the copper surface is thermodynamically or kinetically favorable relative to the formation of the cobalt film on the dielectric surface.

[0022] In some cases, it is desirable to selectively deposit a material on one surface of a substrate relative to a second, different surface of the same substrate. For example, selective deposition can be used to form capping layers, barrier layers, etch stop layers, sacrificial layers, and / or protective layers or to seal pores, such as in porous low-k materials.

[0023] The method of the present invention includes an optional step of contacting the substrate surface with a wet chemical composition to obtain a treated substrate. Exemplary wet chemical treatments include known chemical treatments such as, for example, RCA cleaning chemicals SC-1 and SC-2, aqueous HF, peroxide, H2SO4 / H2O2, NH4OH, buffered HF solutions, and mixtures thereof.

[0024] In a preferred embodiment, the wet chemical composition comprises at least one selected from the group consisting of a composition comprising H2O2 (28% aq), NH4O4 (28-30%) and H2O; HF (0.01%-10% (aq)); peroxide; RCA cleaning chemicals SC-1 and SC-2; and a mixture of H2SO4 / H2O2.

[0025] As known in the art, "RCA cleaning chemicals" refers to a composition comprising a mixture of ammonium hydroxide and hydrogen peroxide, wherein Radio Corporation of America developed the basic cleaning procedure in the 1960s. The RCA Standard-Clean-1 (SC-1) procedure uses a solution of ammonium hydroxide and hydrogen peroxide and water heated to about 70°C. The SC-1 procedure dissolves films and removes Group I and II metals. The Group I and II metals are removed by complexing with the reagents in the SC-1 solution. The RCA Standard-Clean-2 (SC-2) procedure utilizes a mixture of hydrogen peroxide, hydrochloric acid, and water heated to about 70°C. The SC-2 procedure removes metals not removed by the SC-1 procedure.

[0026] The contacting with the wet chemical composition can be performed by any method known to the person skilled in the art, such as for example dipping or spraying.The contacting step can be one separate step or more than one step.

[0027] In some embodiments, the temperature of the wet chemical composition during the contacting step can be, for example, approximately ambient temperature to about 100° C. In other embodiments, the temperature of the wet chemical composition during the contacting step can be, for example, about 55° C. to about 95° C. In other embodiments, the temperature of the wet chemical composition during the contacting step can be, for example, about 60° C. to about 90° C.

[0028] The embodiment further comprises the step of rinsing the substrate surface with deionized water after the step of contacting the substrate surface with the wet chemical composition. The rinsing step is generally performed by any suitable means, such as rinsing the substrate surface with deionized water by immersion or spraying techniques.

[0029] Embodiments further comprise the step of drying at least the surface of the substrate after the rinsing step.The drying step is generally performed by any suitable means, such as application of heat, isopropyl alcohol (IPA) vapor drying, or by centripetal force.

[0030] Embodiments also optionally include a step of treating the surface with hydrogen plasma or ammonia plasma. Suitable processes include plasma treatment (hydrogen plasma, NH3 / NF3 plasma, water plasma, etc.). The optional plasma step is used to remove undesirable deposits on the surface and activate the surface for subsequent deposition of a passivating agent. This plasma treatment can most preferably be carried out after some deposition has been carried out on the surface, so as to remove non-selectively deposited material from the previously passivated surface and remove residual passivating agent after reaching the desired deposition thickness.

[0031] Embodiments include the step of exposing the surface to a vapor comprising at least one organic isocyanate having the structure of Formula I:

[0032] RN=C=O(I),

[0033] wherein R is selected from H, substituted or unsubstituted C1-C 18 Straight chain alkyl, substituted or unsubstituted branched C3-C 18 Alkyl, substituted or unsubstituted C3-C8 cycloalkyl, substituted or unsubstituted C3-C 10 Heterocyclic group, substituted or unsubstituted C3-C 18 Alkenyl, substituted or unsubstituted C4-C 18 Aryl, substituted or unsubstituted C5-C 20 Arylalkyl and substituted or unsubstituted C3-C 10 Alkynyl groups, wherein at least one organic isocyanate selectively reacts with the silicon nitride to passivate the first surface, thereby leaving the second surface substantially unreacted.

[0034] In some embodiments, the organic isocyanate is a fluorine-substituted C1 to C 18 A straight chain alkyl group, the structure of which is selected from C n F 2n+ 1CH2N=C=O and C n F 2n+1 (C2H4)N=C=O. The preferred structure is C n F2 n+1 C1 to C2N=C=O with fluorine substitution 18 The organic isocyanate precursor of the linear alkyl group includes CF3CH2N=C=O, C2F5CH2N=C=O, C3F7CH2N=C=O, C4F9CH2N=C=O, C5F 11 CH2N=C=O、C6F 13 CH2N=C=O、C7F 15 CH2N=C=O、C8F 17 CH2N=C=O and C9F 19 Those of CH2N=C=O.

[0035] In other embodiments, R in Formula I is a chlorine-substituted C1 to C 18 A straight chain alkyl group, whose structure is C n Cl 2n+1 CH2N=C=O. The preferred structure is C n Cl 2n+1 C1 to C2N=C=O with chlorine substitution 18 Straight chain alkyl organic isocyanate precursors include CCl3CH2N=C=O, C2Cl5CH2N=C=O, C3Cl7CH2N=C=O, C4Cl9CH2N=C=O, C5Cl 11 CH2N=C=O、C6Cl 13 CH2N=C=O、C7Cl 15 CH2N=C=O、C8Cl 17 CH2N=C=O and C9Cl 19 Those with CH2N=C=O

[0036] In other embodiments, R in Formula I is a substituted or unsubstituted C3 to C8 cycloalkyl. In such embodiments, the at least one organic isocyanate includes those selected from cyclopropyl isocyanate, cyclobutyl isocyanate, cyclohexyl isocyanate, and methylcyclohexyl isocyanate.

[0037] In other embodiments, R in Formula I is a substituted or unsubstituted C4 to C 18 In such embodiments, the organic isocyanates include those selected from the group consisting of phenyl isocyanate, tolyl isocyanate, dimethylphenyl isocyanate, naphthyl isocyanate, 2-ethylphenyl isocyanate, and ditolyl isocyanate.

[0038] In other embodiments, R in Formula I is an unsubstituted C1 to C 18 Straight chain alkyl, or R is a substituted or unsubstituted branched C3 to C 18 In such embodiments, the organic isocyanates include those selected from methyl isocyanate, ethyl isocyanate, propyl isocyanate, isopropyl isocyanate, n-butyl isocyanate, sec-butyl isocyanate, tert-butyl isocyanate, amyl isocyanate, hexyl isocyanate, octyl isocyanate, decyl isocyanate, dodecyl isocyanate, stearyl isocyanate, 1,1,3,3-tetramethylbutyl isocyanate, and 1-methylheptyl isocyanate.

[0039] In another embodiment, R in Formula I is substituted or unsubstituted C 54 to C 20 In such embodiments, the organic isocyanate comprises benzyl isocyanate.

[0040] As used throughout the specification, the term "alkyl" refers to a saturated hydrocarbon radical that is straight or branched. In some embodiments, the alkyl group has 1-20 carbon atoms, 2-20 carbon atoms, 1-10 carbon atoms, 2-10 carbon atoms, 1-8 carbon atoms, 2-8 carbon atoms, 1-6 carbon atoms, 2-6 carbon atoms, 1-4 carbon atoms, 2-4 carbon atoms, 1-3 carbon atoms, or 2 or 3 carbon atoms. Examples of alkyl groups include, but are not limited to, methyl (Me), ethyl (Et), propyl (e.g., n-propyl and isopropyl), butyl (e.g., n-butyl, tert-butyl, isobutyl), pentyl (e.g., n-pentyl, isopentyl, neopentyl), hexyl, isohexyl, heptyl, octyl, nonyl, 4,4-dimethylpentyl, 2,2,4-trimethylpentyl, decyl, undecyl, dodecyl, 2-methyl-1-propyl, 2-methyl-2- methyl-3- propyl, 2-methyl-4- methyl-5- propyl, 2-methyl-6- methyl-7- propyl, 2-methyl-7- methyl-8- propyl, 2-methyl-9- methyl-10- propyl, 2-methyl-11- propyl, 2-methyl-12- propyl, 2-methyl-13- propyl, 2-methyl-14- propyl, 2-methyl-15- propyl, 2-methyl-16- propyl, 2-methyl-17- propyl, 2-methyl-18- propyl, 2-methyl-19- propyl, 2-methyl-20- propyl, 2-methyl-21- propyl, 2-methyl-22- propyl, 2-methyl-23- propyl, 2-methyl-24- propyl, 2-methyl-2 2-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-3-butyl, 2-methyl-1-pentyl, 2,2-dimethyl-1-propyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, and the like.

[0041] As used throughout the specification, the term "cycloalkyl" refers to a cyclic functional group having 3 to 10 or 4 to 10 carbon atoms. Exemplary cycloalkyl groups include, but are not limited to, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl.

[0042] As used herein, the term "aryl" refers to an aromatic hydrocarbon that is monocyclic, bicyclic, or polycyclic (e.g., having 2, 3, or 4 fused rings). In some embodiments, the aryl group has 6 to 20 carbon atoms or 6 to 10 carbon atoms. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, anthracenyl, phenanthrenyl, indanyl, indenyl, and tetrahydronaphthyl.

[0043] As used herein, the term "arylalkyl" refers to an alkyl group substituted with an aryl group. In some embodiments, the alkyl group is C 1-6 alkyl.

[0044] As used throughout the specification, the term "alkenyl" refers to a group having one or more carbon-carbon double bonds and having 2 to 18 or 2 to 10 carbon atoms. Exemplary alkenyl groups include, but are not limited to, vinyl or allyl.

[0045] As used herein, the term "alkynyl" refers to a straight or branched chain alkyl group having 2 to 20 carbon atoms and one or more carbon-carbon triple bonds. In some embodiments, the alkynyl group has 2 to 10 carbon atoms, 2 to 8 carbon atoms, 2 to 6 carbon atoms, or 2 to 4 carbon atoms. Examples of alkynyl groups include, but are not limited to, acetylene, 1-propylene, 2-propylene, and the like.

[0046] As used herein, the phrase "optionally substituted" means that substitution is optional and, therefore, includes both unsubstituted and substituted atoms and moieties. A "substituted" atom or moiety means that any hydrogen atom on the specified compound or moiety can be replaced with a substituent selected from the specified substituents, provided that the normal valence of the specified compound or moiety is not exceeded and that the substitution results in a stable compound. For example, if a methyl group is optionally substituted, then 1, 2, or 3 hydrogen atoms on the carbon atom within the methyl group can be replaced with 1, 2, or 3 of the substituents recited.

[0047] As used herein, the term "phenyl" refers to -C6H5. A phenyl group may be unsubstituted or substituted with one, two or three suitable substituents.

[0048] As used herein, the term "cycloalkyl" refers to a non-aromatic cyclic hydrocarbon, including cyclized alkyl, alkenyl and alkynyl groups with up to 20 ring-forming carbon atoms. Cycloalkyl has 3-15 ring-forming carbon atoms, 3-10 ring-forming carbon atoms, 3-8 ring-forming carbon atoms, 3-6 ring-forming carbon atoms, 4-6 ring-forming carbon atoms, 3-5 ring-forming carbon atoms or 5 or 6 ring-forming carbon atoms. The ring-forming carbon atoms of cycloalkyl can be optionally substituted with oxo or thio. Cycloalkyl includes but is not limited to monocyclic or polycyclic ring systems, such as fused ring systems, bridged ring systems and spiro ring systems. In some embodiments, the polycyclic ring system includes 2, 3 or 4 fused rings. Examples of cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclopentenyl, cyclohexenyl, cyclohexadienyl, cycloheptatrienyl, norbornyl, norpinyl, norcarnyl, adamantyl, etc. The cycloalkyl group may also have one or more aromatic rings fused to (having a common bond with) the cycloalkyl ring, such as benzo or thienyl derivatives of pentane, pentene, hexane, etc. (e.g., 2,3-dihydro-1H-inden-1-yl or 1H-inden-2(3H)-on-1-yl).

[0049] As used herein, the term "halo" refers to a halogen group and includes, but is not limited to, fluoro, chloro, bromo, and iodo.

[0050] As used herein, the term "heterocycle" or "heterocyclic ring" refers to a 5-7 membered monocyclic or 7-10 membered bicyclic ring system, any ring of which may be saturated or unsaturated, and the ring consists of carbon atoms and 1-3 heteroatoms selected from N, O and S, and wherein the N and S heteroatoms may be optionally oxidized and the N heteroatom may be optionally quaternized, and includes any bicyclic group in which any of the heterocyclic rings defined above is fused to a benzene ring. Heterocycles include rings containing one oxygen or sulfur, one to three nitrogen atoms, or one oxygen or sulfur in combination with one or two nitrogen atoms. The heterocyclic ring may be attached to any heteroatom or carbon atom that results in a stable structure. Examples of heterocyclic groups include, but are not limited to, piperidinyl, piperazinyl, 2-oxopiperazinyl, 2-oxopiperidinyl, 2-oxopyrrolodinyl, 2-oxoazepine Base, nitrogen 1-Hydroxy-1,1-dopamine, 1-dopamine-2-ol, 1-dopamine-3-ol, 1-dopamine-4-ol, 1-dopamine-5-ol, 1-dopamine-6-ol, 1-dopamine-7-ol, 1-dopamine-8-ol, 1-dopamine-9-ol, 1-dopamine-11-ol, 1-dopamine-12-ol, 1-dopamine-13-ol, 1-dopamine-14-ol, 1-dopamine-15-ol, 1-dopamine-16-ol, 1-dopamine-17-ol, 1-dopamine-18-ol, 1-dopamine-19-ol, 2-dopamine-20-ol, 2-dopamine-21-ol, 2-dopamine-22-ol, 2-dopamine-23-ol, 2-dopamine-24-ol, 2-dopamine-25-ol, 2-dopamine-26-ol, 2-dopamine-27-ol, 2-dopamine-28-ol, 2-dopamine-29-ol, 3-dopamine-30-ol, 3-dopamine-31-ol, 3-dopamine-32-ol, 3-dopamine-33-ol, 3-dopamine-34-ol,

[0051] Vapor-phase or gas-phase reactions involve exposing a heated substrate to precursor molecules and / or co-reactants in a suitable chamber that must be able to provide the necessary pressure control and also supply heat to the substrate and / or chamber walls; the chamber should also provide suitable purity for the reactions to take place, typically through high leak integrity and the use of ultra-high purity carrier and reactive gases.

[0052] As used herein and in the appended claims, the terms "reactive gas," "precursor," "reactant," and the like are used interchangeably to refer to a gas comprising a species reactive with the substrate surface. For example, a first "reactive gas" may simply adsorb onto the substrate surface and be available for further chemical reaction with a second reactive gas. These may be used in combination with an ultra-high purity carrier gas (as previously defined) and in any desired mixture with one another (i.e., more than one type of precursor may be used together or in separate, independent steps in any desired order of precursor introduction to form the desired passivation layer).

[0053] Precursors and / or co-reactants can be delivered to the reactor using mass flow controllers (possibly with heated lines), liquid injection vaporizers (possibly with heated lines), or without metering devices (i.e., net introduction of vapor and / or gas from a vessel isolated from the reactor by a simple valve). Any of the aforementioned methods can also be used in combination with each other. Any method of providing gas and / or vapor to the reaction chamber that provides sufficient purity and reproducibility can be used.

[0054] The precursors and / or co-reactants may be introduced into the reactor independently, mixed prior to introduction into the reactor, mixed within the reactor, or introduced in multiple separate steps in any combination of the foregoing, which may include differences in the manner of introduction of the precursors between the steps.

[0055] The temperature range of the reaction can be between room temperature and 400 ° C. In some cases, the temperature range of the reaction can be between room temperature and 200 ° C. Again in other cases, the temperature range of the reaction can be between room temperature and 100 ° C. The pressure range can be between 10-10 Torr to 3000 Torr, and can be maintained under dynamic flow conditions (that is, with a device of valve and butterfly valve type), or can be maintained under static conditions (that is, the vacuum chamber is exposed to the required precursor and / or co-reactant until the required total pressure is reached, and then the chamber is isolated from the precursor and / or co-reactant source and vacuum pump). The reactor can be completely evacuated and re-exposed to new precursors and / or co-reactants as needed multiple times. Precursors and / or co-reactants can be introduced using any desired mixture and / or concentration.

[0056] The exposure of the surface can be carried out for 0.1-60 minutes, preferably 1-5 minutes, most preferably 1 minute. The partial pressure of the isocyanate in the reaction chamber can vary from about 1% of its saturated vapor pressure at the substrate temperature to almost 100% of its saturated vapor pressure. Most preferably, it is between 20% and 50% of the saturated vapor pressure. The chamber pressure can be the same as the partial pressure of the isocyanate vapor, but can be higher when balanced with the atmosphere containing the carrier gas. Preferred carrier gases include N2, He and Ar, but may also include other gases, such as H2, carbon dioxide and dry oxygen. The exposure vapor can be static (not flowing) during the entire or partial exposure period. A preferred embodiment is to flow the vapor of the isocyanate through the exposure chamber together with an optional carrier gas so that the fresh vapor is exposed to the substrate surface during at least a portion of the exposure period.

[0057] The exposure chamber can be maintained at approximately ambient temperature, or can be optionally heated. Heat can be supplied to the outer wall of the chamber (hot wall) or only to the substrate (cold wall reactor). The substrate heating in the cold wall reactor can be achieved by using incident radiation (lamp heating) through a transparent window, by the resistance heating of the resistance heating element in the platform in which the substrate itself or the substrate contacts it, by induction or other means known in the art. The processing temperature is preferably between about 20°C and about 400°C, preferably between 20°C and about 200°C, and most preferably between 20°C and about 100°C. The temperature can be constant during exposure, or can change within a specified temperature range.

[0058] Unreacted vapors of the at least one organic isocyanate can then be optionally removed by evacuating the chamber or purging the chamber with a suitable inert gas before removing the substrate from the chamber or before chemical vapor deposition or atomic layer deposition processing. Optionally, the exposure chamber can also be used for subsequent processing steps to improve processing efficiency, allowing the process to be repeated from step c) (if necessary) to strip the protective film and any non-selective ALD deposits and then reform the protective film.

[0059] The selection of the at least one organic isocyanate and exposure conditions used in the method should be optimized by standard experiments to optimize the selectivity, processing time, reagent cost, etc. of the protection provided for the silicon nitride surface for potential non-selective passivation according to the requirements of the subsequent processing steps. For example, the selectivity can be adjusted / optimized by changing the properties of the R group of at least one organic isocyanate having the structure shown in Formula I. Typically, since reactivity and selectivity are generally negatively correlated, if the two surfaces are chemically similar, it may be necessary to experiment with the R group to optimize the process. For example, there is a difference in reactivity between alkyl R- groups and aryl R- groups; typically, aryl isocyanates (arylisocyanide) have a higher reactivity with surfaces having active hydrogen than alkyl isocyanates (alkylisocyanide). Therefore, in some cases, alkyl isocyanates may be required to selectively passivate SiN without simultaneously passivating adjacent surfaces that also have less reactive active hydrogen atoms.

[0060] Once the silicon nitride surface is passivated, the second surface comprising, for example, silicon oxide is active for further selective reactions (e.g., selective ALD deposition of SiCN on Si-H surfaces). Additional materials that can be selectively deposited on the second surface include silicon films containing oxygen, nitrogen, hydrogen, and carbon (i.e., SiO x 、SiN x 、SiO x N y 、SiC x N y 、SiO x Cy , all of which may also be doped with H), metals, metal nitrides and metal oxides.

[0061] In some embodiments, the metal oxide film is selectively deposited on the second surface. In one embodiment, the metal oxide film can be used as a capping layer on the second surface. The metal oxide film can be deposited, for example, by atomic layer deposition (ALD), plasma enhanced ALD (PEALD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD) or pulsed chemical vapor deposition. According to one embodiment, the metal oxide film can be selected from HfO2, ZrO2, TiO2, Al2O3 and combinations thereof. In some embodiments, the metal oxide film can be deposited by ALD using alternating exposure of a metal organic precursor and an oxidant (e.g., H2O, hydrogen peroxide, plasma excited O2 or O3), as described in detail in U.S. Provisional Patent Application Serial No. 62 / 472,724, filed on March 17, 2017, the entire contents of which are incorporated herein by reference.

[0062] The selective deposition according to the present invention can be, for example, the metal and metal oxide layers disclosed in Hamalainen et al., "Atomic Layer Deposition of Noble Metals and Their Oxides," Chem. Mater. 2014, 26, 786-801 and Johnson et al., "A Brief review of Atomic layer Deposition: From Fundamentals to Applications," Materials Today, Vol. 17, No. 5, June 2014, both of which are incorporated herein by reference in their entirety.

[0063] In some embodiments, the metal film is selectively deposited on the second surface. In one embodiment, the metal film can be used as a capping layer on the second surface. In another embodiment, the metal film can be used as a conductive path (i.e., a line, a pad, or a plug) on ​​the second surface. In another embodiment, the metal film can be deposited, for example, by atomic layer deposition (ALD), plasma enhanced ALD (PEALD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), or pulsed chemical vapor deposition. According to one embodiment, the metal film can be selected from Al, Ti, Co, Rh, Ir, Fe, Ru, Os, Mn, Tc, Re, Cu, Ag, Au, Ni, Pd, or Pt, and combinations thereof.

[0064] In some embodiments, the metal or metal nitride film is selectively deposited on the second surface. In one embodiment, the metal or metal nitride film can be used as a capping layer on the second surface. In another embodiment, the metal or metal nitride film can be used as a diffusion barrier. The metal or metal nitride film can be deposited, for example, by atomic layer deposition (ALD), plasma enhanced ALD (PEALD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD) or pulsed chemical vapor deposition. Examples are found in, for example, IBM Research Report, "Atomic Layer Deposition of Metal and Metal Nitride Thin Films: Current Research Efforts and Applications for Semiconductor Device Processing," RC22737 (WO303-012), March 5, 2003.

[0065] During the selective deposition process, the aforementioned protective surface previously selectively deposited on the silicon nitride surface with at least one organic isocyanate may begin to react or otherwise become less inert. The optional reapplication of the at least one organic isocyanate (with or without any aqueous or plasma pretreatment step) may optionally be repeated to prevent or delay non-selective deposition on the silicon nitride surface.

[0066] In some embodiments, the passivation on a first surface of a substrate as described herein (e.g., a silicon nitride surface of a substrate) is at least about 90% selective, at least about 95% selective, at least about 96%, 97%, 98%, or 99% or more selective relative to a second surface of the substrate. In some embodiments, the passivation occurs only on the first surface and not on the second surface. In some embodiments, the passivation on the first surface of the substrate is at least about 70% selective, or at least about 80% selective relative to the second surface of the substrate, which may be sufficiently selective for certain specific applications. In some embodiments, the passivation on the first surface of the substrate is at least about 50% selective relative to the second surface of the substrate, which may be sufficiently selective for certain specific applications.

[0067] Wet chemical cleaning can be used to remove the passivation layer. Exemplary wet chemical cleaning includes acidic, alkaline, and oxidizing (e.g., peroxide-containing) wet chemical compositions known in the art and described above for the optional step of contacting the substrate with the wet chemical composition. Another method of removing the passivation layer is by applying heat or other energy.

[0068] Example 1: A 300 mm diameter silicon wafer (substrate) having a patterned surface comprising silicon nitride and silicon oxide features was immersed in a bath containing 1% aqueous hydrofluoric acid (0.3 mol / L) for 60 seconds, then rinsed with degassed deionized water and dried under nitrogen. The wafer was transferred to a deposition chamber, which was evacuated and heated to 100°C. Vapor of n-octyl isocyanate was delivered to the chamber from a source container heated to 70°C and allowed to soak for 5 minutes. The chamber was again evacuated. Cyclic atomic layer deposition of titanium oxide was performed in the presence of the substrate by alternating tetrakis(dimethylamino)titanium exposure followed by purge, and then water vapor exposure followed by purge, without exposing the substrate to air. The deposition thickness on the silicon oxide portion of the substrate was greater than the deposition thickness on the silicon nitride portion of the substrate.

[0069] Comparative Example 2: A 300 mm diameter silicon wafer (substrate) having a patterned surface comprising silicon nitride and silicon oxide features was immersed in a bath containing 1% aqueous hydrofluoric acid (0.3 mol / L) for 60 seconds, then rinsed with degassed deionized water and dried under nitrogen. The wafer was transferred to a deposition chamber, which was evacuated and heated to 100° C. Cyclic atomic layer deposition of titanium oxide was performed in the presence of the substrate by alternating tetrakis(dimethylamino)titanium exposure followed by purge, and subsequent water vapor exposure followed by purge, without exposing the substrate to air. The deposition thickness on the silicon oxide portion of the substrate was substantially the same as the deposition thickness on the silicon nitride portion of the substrate.

[0070] Example 3: A 300 mm diameter silicon wafer (substrate) having a patterned surface comprising silicon nitride and silicon oxide features was immersed in a bath containing 0.5% aqueous hydrofluoric acid (0.1 mol / L) for 30 seconds, then rinsed with degassed deionized water and dried under nitrogen. The wafer was then immersed in a solution containing 10% by weight of octadecyl isocyanate dissolved in anhydrous hexane and allowed to stand for 30 minutes. The wafer was then removed, rinsed with anhydrous hexane and dried under a stream of nitrogen. The wafer was transferred to a deposition chamber, which was evacuated and heated to 100°C. Cyclic atomic layer deposition of titanium oxide was performed in the presence of the substrate by alternating tetrakis(dimethylamino)titanium exposure followed by purge, and subsequent water vapor exposure followed by purge, without exposing the substrate to air. The deposition thickness on the silicon oxide portion of the substrate was greater than the deposition thickness on the silicon nitride portion of the substrate.

[0071] Example 4: A 300 mm diameter silicon wafer (substrate) having a patterned surface comprising silicon nitride and silicon oxide features was immersed in a bath containing 0.5% aqueous hydrofluoric acid (0.1 mol / L) for 60 seconds, then rinsed with degassed deionized water and dried under nitrogen. The wafer was transferred to a deposition chamber, which was evacuated and heated to 100°C. Vapor of n-octyl isocyanate was delivered to the chamber from a source container heated to 70°C and allowed to soak for 15 minutes. The chamber was again evacuated. Cyclic atomic layer deposition of silicon oxide was performed in the presence of the substrate by alternating exposure to di-sec-butylaminosilane vapor followed by purge, and subsequent exposure to 5% ozone in oxygen followed by purge, without exposing the substrate to air. The deposition thickness on the silicon oxide portion of the substrate was greater than the deposition thickness on the silicon nitride portion of the substrate.

[0072] Example 5: A 300 mm diameter silicon wafer (substrate) having a patterned surface comprising silicon nitride and silicon oxide features was immersed in a bath containing 0.2% aqueous hydrofluoric acid (0.06 mol / L) for 60 seconds, then rinsed with degassed deionized water and dried under nitrogen. The wafer was transferred to a deposition chamber, which was evacuated and heated to 100°C. Vapor of n-octyl isocyanate was delivered to the chamber from a source container heated to 70°C and allowed to soak for 5 minutes. The chamber was again evacuated. Cyclic atomic layer deposition of titanium oxide was performed in the presence of the substrate by alternating tetrakis(dimethylamino)titanium exposure followed by purge, then water vapor exposure followed by purge, and then n-octyl isocyanate exposure followed by purge, without exposing the substrate to air. The deposition thickness on the silicon oxide portion of the substrate was greater than the deposition thickness on the silicon nitride portion of the substrate.

[0073] Example 6: A 300 mm diameter silicon wafer (substrate) having a patterned surface comprising silicon nitride and cobalt features was immersed in a bath containing 1% aqueous hydrofluoric acid (0.3 mol / L) for 60 seconds, then rinsed with degassed deionized water and dried under nitrogen. The wafer was transferred to a deposition chamber which was evacuated and heated to 100°C. Vapor of n-octyl isocyanate was delivered to the chamber from a source container heated to 70°C and allowed to soak for 5 minutes. The chamber was again evacuated. Cyclic atomic layer deposition of titanium oxide was performed in the presence of the substrate by alternating tetrakis(dimethylamino)titanium exposure followed by purge, and then water vapor exposure followed by purge, without exposing the substrate to air. The deposition thickness on the cobalt portion of the substrate was greater than the deposition thickness on the silicon nitride portion of the substrate.

[0074] While the principles of the present invention have been described above in conjunction with the preferred embodiments, it should be clearly understood that this description is made by way of example only and is not intended to limit the scope of the invention.

Claims

1. A method for selectively passivating a substrate surface, wherein the substrate surface comprises at least a first surface comprising silicon nitride and at least a second surface comprising a material other than silicon nitride, the method comprising the steps of: a. Optionally, treating the substrate surface with hydrogen plasma or ammonia plasma; and b. exposing the substrate surface to a vapor comprising at least one organic isocyanate having a structure according to Formula I: RN=C=O (I), wherein R is selected from H, substituted or unsubstituted C1-C 18 Straight chain alkyl, substituted or unsubstituted branched C3-C 18 Alkyl, substituted or unsubstituted C3-C8 cycloalkyl, substituted or unsubstituted C3-C 10 Heterocyclic group, substituted or unsubstituted C3-C 18 Alkenyl, substituted or unsubstituted C4-C 18 Aryl, substituted or unsubstituted C5-C 20 Arylalkyl and substituted or unsubstituted C3-C 10 An alkynyl group, wherein the at least one organic isocyanate selectively reacts with the silicon nitride to passivate the first surface, thereby leaving the second surface unreacted.

2. The method according to claim 1, further comprising the following steps performed before steps a and b: contacting the substrate surface with a wet chemical composition; Rinse the substrate surface with deionized water; and drying the substrate surface, The wet chemical composition comprises at least one selected from the group consisting of: 0.01%-5% HF aqueous solution; peroxide; RCA cleaning chemicals SC-1 and SC-2; and a mixture of H2SO4 / H2O2.

3. The method of claim 1, wherein the second surface comprises at least one selected from the group consisting of SiO2, metal oxides, copper, cobalt, tungsten, amorphous silicon, polycrystalline silicon, single crystal silicon, germanium, and amorphous germanium hydride. The method of claim 3 , wherein the second surface comprises SiO 2 .

5. The method of claim 1, wherein the at least one organic isocyanate is a compound having structure C n F 2n+1 Fluorine-substituted C1 to C2 in CH2N=C=O 18 A straight chain alkyl group wherein n is 1 to 17.

6. The method according to claim 5, wherein the at least one organic isocyanate is selected from the group consisting of CF3CH2N=C=O, C2F5CH2N=C=O, C3F7CH2N=C=O, C4F9CH2N=C=O, C5F 11 CH2N=C=O、C6F 13 CH2N=C=O、C7F 15 CH2N=C=O、C8F 17 CH2N=C=O and C9F 19 CH2N=C=O.

7. The method according to claim 1, wherein R is a compound having the structure C n Cl 2n+1 C1 to C2 of CH2N=C=O substituted by chlorine 18 A straight chain alkyl group wherein n is 1 to 17.

8. The method according to claim 7, wherein the at least one organic isocyanate is selected from the group consisting of CCl3CH2N=C=O, C2Cl5CH2N=C=O, C3Cl7CH2N=C=O, C4Cl9CH2N=C=O, C5Cl 11 CH2N=C=O、C6Cl 13 CH2N=C=O、C7Cl 15 CH2N=C=O、C8Cl 17 CH2N=C=O and C9Cl 19 CH2N=C=O.

9. The method according to claim 1, wherein R is a substituted or unsubstituted C3 to C8 cycloalkyl group.

10. The method according to claim 9, wherein the at least one organic isocyanate is selected from cyclopropyl isocyanate, cyclobutyl isocyanate, cyclohexyl isocyanate and methylcyclohexyl isocyanate.

11. The method according to claim 1, wherein R is a substituted or unsubstituted C4 to C 18 Aryl.

12. The method according to claim 11, wherein the at least one organic isocyanate is selected from phenyl isocyanate, tolyl isocyanate, dimethylphenyl isocyanate, naphthyl isocyanate, 2-ethylphenyl isocyanate and xylyl isocyanate.

13. The method according to claim 1, wherein R is an unsubstituted C1 to C 18 Straight chain alkyl, or R is a substituted or unsubstituted branched C3 to C 18 alkyl.

14. The method according to claim 13, wherein the at least one organic isocyanate is selected from the group consisting of methyl isocyanate, ethyl isocyanate, propyl isocyanate, isopropyl isocyanate, n-butyl isocyanate, sec-butyl isocyanate, tert-butyl isocyanate, amyl isocyanate, hexyl isocyanate, octyl isocyanate, decyl isocyanate, dodecyl isocyanate, stearyl isocyanate, 1,1,3,3-tetramethylbutyl isocyanate and 1-methylheptyl isocyanate.

15. The method according to claim 1, wherein R is a substituted or unsubstituted C5 to C 20 Arylalkyl.

16. The method of claim 15, wherein the at least one organic isocyanate is benzyl isocyanate.

17. The method of claim 1, wherein the exposing step is performed with vapor of the at least one organic isocyanate.

18. A method of selectively depositing a film on a substrate surface, wherein the substrate surface includes at least a first surface comprising silicon nitride and at least a second surface comprising a material other than silicon nitride, the method comprising the steps of: a. Optionally, treating the substrate surface with hydrogen plasma or ammonia plasma; b. exposing the substrate surface to a vapor comprising at least one organic isocyanate having a structure according to Formula I: RN=C=O (I), wherein R is selected from H, substituted or unsubstituted C1-C 18 Straight chain alkyl, substituted or unsubstituted branched C3-C 18 Alkyl, substituted or unsubstituted C3-C8 cycloalkyl, substituted or unsubstituted C3-C 10 Heterocyclic group, substituted or unsubstituted C3-C 18 Alkenyl, substituted or unsubstituted C4-C 18 Aryl, substituted or unsubstituted C5-C 20 Arylalkyl and substituted or unsubstituted C3-C 10 an alkynyl group, wherein the at least one organic isocyanate selectively reacts with the silicon nitride to passivate the first surface, thereby leaving the second surface unreacted; and c. exposing the substrate surface to one or more deposition precursors to selectively deposit a film on the second surface relative to the first surface.

19. The method according to claim 18, further comprising the following steps performed before steps a, b and c: contacting the substrate surface with a wet chemical composition; Rinse the substrate surface with deionized water; and drying the substrate surface, The wet chemical composition comprises at least one selected from the group consisting of 0.01%-5% HF aqueous solution; peroxide; RCA cleaning chemicals SC-1 and SC-2; and H2SO4 / H2O2 mixture.

20. The method of claim 18, wherein the second surface comprises at least one selected from the group consisting of SiO2, metal oxides, copper, cobalt, tungsten, amorphous silicon, polycrystalline silicon, single crystal silicon, germanium, and amorphous hydrogenated germanium.

21. The method of claim 20, wherein the second surface comprises SiO2.

22. The method of claim 18, wherein the at least one organic isocyanate is a ester having structure C n F 2n+ 1CH2N=C=O fluorine-substituted C1 to C 18 A straight chain alkyl group wherein n is 1 to 17.

23. The method according to claim 22, wherein the at least one organic isocyanate is selected from the group consisting of CF3CH2N=C=O, C2F5CH2N=C=O, C3F7CH2N=C=O, C4F9CH2N=C=O, C5F 11 CH2N=C=O、C6F 13 CH2N=C=O、C7F 15 CH2N=C=O、C8F 17 CH2N=C=O and C9F 19 CH2N=C=O.

24. The method of claim 18, wherein R is a compound having the structure C n Cl 2n+1 C1 to C2 of CH2N=C=O substituted by chlorine 18 A straight chain alkyl group wherein n is 1 to 17.

25. The method according to claim 24, wherein the at least one organic isocyanate is selected from the group consisting of CCl3CH2N=C=O, C2Cl5CH2N=C=O, C3Cl7CH2N=C=O, C4Cl9CH2N=C=O, C5Cl 11 CH2N=C=O、C6Cl 13 CH2N=C=O、C7Cl 15 CH2N=C=O、C8Cl 17 CH2N=C=O and C9Cl 19 CH2N=C=O.

26. The method of claim 18, wherein R is a substituted or unsubstituted C3 to C8 cycloalkyl group.

27. The method of claim 26, wherein the at least one organic isocyanate is selected from cyclopropyl isocyanate, cyclobutyl isocyanate, cyclohexyl isocyanate, and methylcyclohexyl isocyanate.

28. The method of claim 18, wherein R is a substituted or unsubstituted C4 to C 18 Aryl.

29. The method of claim 28, wherein the at least one organic isocyanate is selected from the group consisting of phenyl isocyanate, tolyl isocyanate, dimethylphenyl isocyanate, naphthyl isocyanate, 2-ethylphenyl isocyanate, and xylyl isocyanate.

30. The method of claim 18, wherein R is unsubstituted C1 to C 18 Straight chain alkyl, or R is a substituted or unsubstituted branched C3 to C 18 alkyl.

31. The method of claim 30, wherein the at least one organic isocyanate is selected from the group consisting of methyl isocyanate, ethyl isocyanate, propyl isocyanate, isopropyl isocyanate, n-butyl isocyanate, sec-butyl isocyanate, tert-butyl isocyanate, amyl isocyanate, hexyl isocyanate, octyl isocyanate, decyl isocyanate, dodecyl isocyanate, stearyl isocyanate, 1,1,3,3-tetramethylbutyl isocyanate, and 1-methylheptyl isocyanate.

32. The method of claim 18, wherein R is a substituted or unsubstituted C5 to C 20 Arylalkyl.

33. The method of claim 32, wherein the at least one organic isocyanate is benzyl isocyanate.

34. The method of claim 18, wherein the exposing step is performed with vapor of the at least one organic isocyanate.