TW201843337A - Process for the generation of thin silicon-containing films - Google Patents

Abstract

The present invention is in the field of processes for the generation of thin inorganic films on substrates. In particular, the present invention relates to a process for producing a silicon- containing film comprising depositing the compound of general formula (I) or (II) R3Si-Si---X (I) onto a solid substrate, wherein R is an alkyl group, an alkenyl group, an aryl group, or a silyl group, X is an olefinic or aromatic group forming a [pi] bond to the silicon atom, Z is a neutral ligand, and n is 1 or 2.

Description

 Method for producing a thin film containing ruthenium  

The genus of the present invention is a method of producing a thin ruthenium-containing film on a substrate, particularly an atomic layer deposition method.

With the current miniaturization, for example, in the semiconductor industry, the demand for thin inorganic films on substrates has increased, and the requirements for the quality of such films have become more stringent. Thin inorganic films are used for different purposes, such as barrier layers of precision structures, dielectrics, conductive properties, covering or separation. Several methods for producing a thin inorganic film are known. One of them is to deposit a film-forming compound from a gaseous state on a substrate. Therefore, there is a need for volatile precursors that can be deposited on a substrate and subsequently converted to the desired composition in the film.

A ruthenium containing film of ruthenium halide, such as Si ₂ Cl ₆ , is typically used. However, such compounds are difficult to handle and typically leave a large amount of residual halogen in the film, which is undesirable for some applications.

No. 8,535,760 discloses a CVD process using a hydrogen or halogen substituted tetradecyldipine precursor. However, these precursors are so unstable that they are almost impossible to handle and do not produce a film of sufficient quality.

Protchenko et al., Angewandte Chemie International Edition, Vol. 52 (2013), pp. 568-571, discloses a mercapto-substituted silylene compound. However, the applicability of the gas phase process has not been explained.

It is an object of the present invention to provide a method for producing a high quality, such as a low impurity mass and a uniform film thickness and composition of a thin hafnium-containing film. In addition, it is directed to methods of using compounds that are easier to synthesize and process. The method should also be flexible with parameters such as temperature or pressure to accommodate a variety of different applications.

These objects are achieved by a process for preparing a ruthenium-containing film comprising depositing a compound of the formula (I) or (II) on a solid substrate, R ₃ Si-Si---X (I)

Wherein R is an alkyl group, an alkenyl group, an aryl group or a fluorenyl group, X is an olefin group or an aromatic group which forms a π bond with a ruthenium atom, Z is a neutral ligand, and n is 1 or 2.

The invention further relates to the use of a compound of the formula (I) or (II), wherein R is an alkyl group, an alkenyl group, an aryl group or a fluorenyl group, and X is an olefin group which forms a π bond with a ruthenium atom for a film deposition method Or an aromatic group, Z is a neutral ligand, and n is 1 or 2.

The invention further relates to compounds of the formula (I) or (II), wherein R is alkyl, alkenyl, aryl or indenyl, and X is an alkene group or an aromatic group which forms a π bond with a ruthenium atom, Z It is a neutral ligand and n is 1 or 2.

Preferred embodiments of the invention are found in the context of the embodiments and claims. Combinations of different specific examples are within the scope of the invention.

In the compound of the formula (I) or (II), the oxidation state of the ruthenium atom bonded to X is +2. Thus, the compound of formula (I) or (II) is commonly referred to as an anthracenylene group. R is an alkyl group, an alkenyl group, an aryl group or a fluorenyl group. All R may be the same or different from each other, for example, two Rs are the same and one R is different from the other or all three Rs are different from each other. Preferably, all R are the same. A preferred specific example of R shown below means that at least one of R is a preferred embodiment, more preferably at least two of R, especially all R are preferred embodiments.

The alkyl group can be a straight or branched chain. Examples of linear alkyl groups are methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-decyl, n-decyl. Examples of branched alkyl groups are isopropyl, isobutyl, second butyl, tert-butyl, 2-methyl-pentyl, 2-ethyl-hexyl, cyclopropyl, cyclohexyl, indanyl. , ice base. Preferably, the alkyl group is a C ₁ to C ₈ alkyl group, more preferably a C ₁ to C ₆ alkyl group, especially a C ₁ to C ₄ alkyl group such as a methyl group, an ethyl group, an isopropyl group or a tert-butyl group. The alkyl group can be substituted, for example, by a halogen such as F, Cl, Br, I, especially F; a hydroxyl group; an ether group; or an amine such as a dialkylamine.

The alkenyl group contains at least one carbon-carbon double bond. The double bond may comprise a carbon atom, the alkenyl group being bonded to the rest of the molecule by the carbon atom, or the double bond may be located away from the alkenyl bond to the rest of the molecule, preferably the double bond is located away from the alkenyl bond The position of the knot to the rest of the molecule. The alkenyl group may be a straight chain or a branched chain. Examples of linear alkenyl groups in which a double bond includes a carbon atom and an alkenyl group is bonded to the remainder of the molecule by the carbon atom include 1-vinyl, 1-propenyl, 1-n-butenyl, 1-positive Pentenyl, 1-n-hexenyl, 1-n-heptenyl, 1-n-octenyl. Examples of linear alkenyl groups in which the double bond is located away from the alkenyl bond to the rest of the molecule include 1-n-propen-3-yl, 2-buten-1-yl, 1-butene-3- Base, 1-buten-4-yl, 1-hexene-6-yl. Examples of branched alkenyl groups in which a double bond includes a carbon atom and an alkenyl group is bonded to the remainder of the molecule by the carbon atom include 1-propen-2-yl, 1-n-buten-2-yl, 2- Buten-2-yl, cyclopenten-1-yl, cyclohexen-1-yl. Examples of branched alkenyl groups in which the double bond is located away from the alkenyl bond to the rest of the molecule include 2-methyl-1-buten-4-yl, cyclopenten-3-yl, cyclohexene -3- base. Examples of alkenyl groups having more than one double bond include 1,3-butadien-1-yl, 1,3-butadien-2-yl, cyclopentadien-5-yl. Preferably, the alkenyl group is a C ₁ to C ₈ alkenyl group, more preferably a C ₁ to C ₆ alkenyl group, especially a C ₁ to C ₄ alkenyl group.

The aryl group includes an aromatic hydrocarbon such as phenyl, cyclopentadienyl, naphthyl, anthracenyl, phenanthryl; and a heteroaromatic group such as pyrrolyl, furyl, thienyl, pyridyl, quinolyl, Benzofuranyl, benzothienyl, thienothiophenyl. A number of such groups or combinations of such groups are also possible, such as biphenyl, thienophenyl or furylthiophenyl. The aryl group may, for example, be a halogen such as a fluoride, a chloride, a bromide or an iodide; a pseudohalogen such as a cyanide, a cyanate ester, a thiocyanate; an alcohol; an alkyl group; an alkoxy group; an amine group such as Dimethylamine or bis(trimethylmethyl)amine; or aryl substitution. The aryl group is preferably a C ₅ to C ₂₀ aryl group, more preferably a C ₆ to C ₁₆ aryl group. Preferred are aromatic hydrocarbons substituted with an alkyl group and an alkoxy group, especially 2,4,6-trimethylphenyl, 2-isopropylphenyl, 2,6-diisopropylphenyl, and 2,4,6-Triisopropylphenyl, pentamethylcyclopentadienyl, 2,6-dimethoxyphenyl and 2,4,6-trimethoxyphenyl.

The fluorenyl group is a ruthenium atom typically having three substituents. The fluorenyl group preferably has the formula SiE ₃ wherein E is hydrogen, alkyl, alkoxy, alkenyl, aryl, aryloxy, amine or fluorenyl. It is possible that all three Es are the same or two Es are the same and the other E is different, or all three Es are different from each other. It is also possible that two Es together form a ring including Si atoms. The alkyl and aryl groups are as described above. Examples of the fluorenyl group include SiH ₃ , methyl fluorenyl, trimethyl decyl, triethyl decyl, tri-n-propyl fluorenyl, triisopropyl decyl, tricyclohexyl decyl, dimethyl- Tributyl fluorenyl, dimethylcyclohexyl fluorenyl, methyl-diisopropyl fluorenyl, triphenyl fluorenyl, phenyl fluorenyl, dimethylphenyl fluorenyl, pentamethyldiindenyl.

According to the invention, X is an olefinic group or an aromatic group which forms a π bond with a ruthenium atom. Preferably, X is a cyclopentadienyl derivative. The cyclopentadienyl derivative includes a benzocycloalkyl derivative such as an anthracenyl group or a fluorenyl group, of which a cyclopentadienyl group is preferred. The cyclopentadienyl derivative may be substituted with one or more alkyl, alkenyl, aryl or decyl groups. If the cyclopentadienyl derivative is substituted more than once, it may be substituted with the same substituent or a different substituent. Preferably, the cyclopentadienyl derivative is alkyl-substituted, such as tetramethylcyclopentadienyl, more preferably, all positions are substituted with an alkyl group, such as pentamethylcyclopentadienyl, pentaethyl Cyclopentadienyl or pentaisopropylcyclopentadienyl.

Preferred olefinic groups which form a π bond with a ruthenium atom are an anionic dienes or an anionic allyl group. Preferred examples of the anionic dienes are 1,3-pentadienyl, 2,4-di-t-butyl-1,3-pentadienyl, 2-methyl-4-t-butyl-1, 3-pentadienyl, 1,3-hexadienyl, 1,3-cyclohexadienyl, 5,5-dimethyl-1,3-cyclohexadienyl and 1,3-cyclooctyl Dienyl. Examples of anionic allyl groups are propenyl, 2-butenyl, 3-methyl-2-butenyl.

According to the invention, Z is a neutral ligand. The compound of the formula (II) contains one or two Z, i.e., n is 1 or 2, preferably 1. Suitable neutral ligands include carbene; amines, including trialkylamines such as trimethylamine; phosphines, including trialkylphosphines such as trimethylphosphine, and trihalophosphines such as trifluorophosphine; sulfides, including Dialkyl sulfides, such as dimethyl sulfide; pyridine, including amine substituted pyridines such as 4-dimethylaminopyridine.

Preferred carbene is an N-heterocyclic carbene such as N,N-dialkylimidazol-2-ylidene, or N,N-dialkylimidazolidine-2-ylidene; and acyclic carbene, Such as bis(dialkylamino)methylene.

Preferred examples of the N,N-dialkylimidazol-2-ylidene group are 1,3-dialkylimidazol-2-ylidene, 1,3-diisopropylimidazol-2-ylidene, 1,3 -di-tert-butylimidazol-2-ylidene, 1,3-diphenylimidazol-2-ylidene, 1,3-di Imidazol-2-ylidene, 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, 1,3-bis(trimethyldecyl)imidazol-2-ylidene 1,3,4,5-tetramethylimidazole-2-ylidene, 1,3-diisopropyl-4,5-dimethylimidazolium-2-ylidene, 1,3-diphenyl- 4,5-Dimethylimidazole-2-ylidene, 1,3-di-tert-butyl-4,5-dimethylimidazolium-2-ylidene, 1,3-di -4,5-dimethylimidazolium-2-ylidene, 1,3-bis(2,6-diisopropylphenyl)-4,5-dimethylimidazolium-2-ylidene, 1,3 - bis(trimethyldecyl)-4,5-dimethylimidazolium-2-ylidene, 1,3-dimethyl-4,5-bis(trifluoromethyl)imidazol-2-ylidene, 1,3-Diisopropyl-4,5-bis(trifluoromethyl)imidazol-2-ylidene, 1,3-di-tert-butyl-4,5-bis(trifluoromethyl)imidazole- 2-subunit, 1.3-diphenyl-4,5-bis(trifluoromethyl)imidazol-2-ylidene, 1,3-di -4,5-bis(trifluoromethyl)imidazol-2-ylidene, 1,3-bis(2,6-diisopropylphenyl)-4,5-bis(trifluoromethyl)imidazole- 2-subunit, 1,3-bis(trimethyldecyl)-4,5-bis(trifluoromethyl)imidazol-2-ylidene.

Preferred examples of the N,N-dialkylimidazolidine-2-ylidene are 1,3-dimethylimidazolidin-2-ylidene, 1,3-diisopropylimidazolidin-2-ylidene, 1,3-di-tert-butylimidazolidine-2-ylidene, 1,3-diphenylimidazolidine-2-ylidene, 1,3-di Imidazolidinium-2-ylidene, 1,3-bis(2,6-diisopropylphenyl)imidazolidine-2-ylidene, 1,3-bis(trimethyldecyl)imidazolidin-2 -subunit, 1,3,4,5-tetramethylimidazolidin-2-ylidene, 1,3-diisopropyl-4,5-dimethylimidazolidin-2-ylidene, 1,3 -diphenyl-4,5-dimethylimidazolidin-2-ylidene, 1,3-di-tert-butyl-4,5-dimethylimidazolidin-2-ylidene, 1,3-di -4,5-dimethylimidazolidin-2-ylidene, 1,3-bis(2,6-diisopropylphenyl)-4,5-dimethylimidazolidin-2-ylidene, 1 ,3-bis(trimethyldecyl)-4,5-dimethylimidazolidin-2-ylidene, 1,3-dimethyl-4,5-bis(trifluoromethyl)imidazolidin-2 -subunit, 1,3-diisopropyl-4,5-bis(trifluoromethyl)imidazolidin-2-ylidene, 1,3-di-tert-butyl-4,5-bis(trifluoro Methyl)imidazolidine-2-ylidene, 1,3-diphenyl-4,5-bis(trifluoromethyl)imidazolidin-2-ylidene, 1,3-di -4,5-bis(trifluoromethyl)imidazolidine-2-ylidene, 1,3-bis(2,6-diisopropylphenyl)-4,5-bis(trifluoromethyl)imidazole Pyridin-2-ylidene, 1,3-bis(trimethyldecyl)-4,5-bis(trifluoromethyl)imidazolidin-2-ylidene, 1,3,4,4,5,5 - hexamethylimidazolidin-2-ylidene.

Preferred examples of the bis(dialkylamino)methylene group are bis(dimethylamino)methylene, bis(diisopropylamino)methylene, bis(di-t-butylamino)methylene. , bis(diphenylamino)methylene, double (two Amino group, methylene, bis(bis(2,6-diisopropylphenyl)amino)methylene, bis(trimethyldecyl)methylene.

Preferably, the compound of formula (I) or (II) has a molecular weight of at most 1200 g/mol, more preferably at most 1000 g/mol, especially at most 800 g/mol.

Some preferred examples of the compound of the formula (I) or (II) are provided in the following table.

Cp* represents pentamethylcyclopentadienyl, CpMe ₄ H represents tetramethylcyclopentadienyl, CpEt ₅ represents pentaethylcyclopentadienyl, and Cp(iPr) 5 represents pentaisopropylcyclopenta Alkenyl, TBP stands for 2,4-di-t-butyl-1,3-pentadienyl, TMS stands for trimethylsulfonyl, TBDMS stands for tert-butyl-dimethylfluorenyl, Me stands for methyl, Et represents an ethyl group, iPr represents an isopropyl group, NHC-Me represents a 1,3,4,5-tetramethylimidazole-2-ylidene group, and DMAP represents a 4-dimethylaminopyridine.

The synthesis of the compound of the formula (I) or (II) can be carried out by making X-Si-(Hal) ₃ (wherein Hal represents halogen, preferably chlorine or bromine) and R ₃ SiM (wherein M represents a non-polar solvent) Preferably, a hydrocarbon such as an alkali metal in hexane, preferably sodium or potassium, is reacted to achieve. The reaction is preferably carried out at or below room temperature and usually takes between 10 minutes and 5 hours.

The compounds of formula (I) or (II) used in the process according to the invention are preferably used in high purity to obtain the best results. High purity means that the material used contains at least 90% by weight of a compound of the formula (I) or (II), preferably at least 95% by weight of a compound of the formula (I) or (II), more preferably at least 98% by weight of the formula ( A compound of I) or (II), especially at least 99% by weight of a compound of the formula (I) or (II). Purity can be determined by basic analysis according to DIN 51721 (Prufung fester Brennstoffe-Bestimmung des Gehaltes an Kohlenstoff und Wasserstoff-Verfahren nach Radmacher-Hoverath, August 2001).

The compound of formula (I) or (II) can be deposited from a gaseous or hazy state. It can be made into a gaseous or fog state by heating it to a high temperature. In any case, it is necessary to select a temperature lower than the decomposition temperature of the compound of the formula (I) or (II). Preferably, the heating temperature is in the range of slightly above room temperature to 400 ° C, more preferably from 30 ° C to 300 ° C, even more preferably from 40 ° C to 250 ° C, especially from 50 ° C to 200 ° C.

Another method of bringing a compound of formula (I) or (II) into a gaseous or mist state is direct liquid injection (DLI), as described, for example, in US 2009/0 226 612 A1. In this process, the compound of formula (I) or (II) is typically dissolved in a solvent and sprayed in a carrier gas or vacuum. The compound of the formula (I) or (II) is brought to a gaseous state or to a haze state depending on the vapor pressure, temperature and pressure of the compound of the formula (I) or (II). Various solvents may be used, provided that the compound of the formula (I) or (II) exhibits sufficient solubility in the solvent, such as at least 1 g/l, preferably at least 10 g/l, more preferably at least 100 g/l. Examples of such solvents are coordination solvents such as tetrahydrofuran, Alkane, diethoxyethane, pyridine; or a non-coordinating solvent such as hexane, heptane, benzene, toluene or xylene. Solvent mixtures are also suitable. Aerosols comprising a compound of formula (I) or (II) contain very fine droplets or solid particles. Preferably, the droplets or solid particles have a weight average diameter of no more than 500 nm, more preferably no more than 100 nm. The weight average diameter of the droplets or solid particles can be determined by dynamic light scattering as described in ISO 22412:2008. It is also possible that one of the compounds of the formula (I) or (II) is in a gaseous state and the remainder is in a haze state, for example, because the vapor pressure of the compound of the formula (I) or (II) is limited, resulting in a misty state. The compound of formula (I) or (II) is partially evaporated.

Alternatively, the metal-containing compound can be made by direct liquid evaporation (DLE) as described, for example, by J. Yang et al. (Journal of Materials Chemistry C, Vol. 3 (2015) pp. 12098-12106). Becomes a gaseous state. In this method, a metal-containing compound or a reducing agent is mixed with a solvent such as a hydrocarbon such as tetradecane, and heated at a temperature lower than the boiling point of the solvent. By evaporating the solvent, the metal-containing compound or reducing agent becomes gaseous. This method has the advantage of no particulate contaminant formation on the surface.

Preferably, the compound of formula (I) or (II) is brought to a gaseous or hazy state under reduced pressure. In this way, the process can generally be carried out at lower heating temperatures, resulting in a reduced decomposition of the compound of formula (I) or (II). It is also possible to push a compound of the formula (I) or (II) in a gaseous or mist state onto a solid substrate using an increased pressure. Usually, an inert gas such as nitrogen or argon is used as a carrier gas for this purpose. Preferably, the pressure is from 10 bar to 10 ^-7 mbar, more preferably from 1 bar to 10 ^-3 mbar, especially from 10 to 0.1 mbar, such as 1 mbar. It is also possible to deposit a compound of the formula (I) or (II) from a solution or to contact a solid substrate. For compounds that are not sufficiently stable to evaporate, it is advantageous from solution deposition. However, the solution needs to be of high purity to avoid undesirable contamination on the surface. From solution deposition, a solvent which does not react with a compound of the formula (I) or (II) is usually required. Examples of the solvent are ethers such as diethyl ether, methyl-tert-butyl ether, tetrahydrofuran, 1,4-two Ketones such as acetone, methyl ethyl ketone, cyclopentanone; esters such as ethyl acetate; lactones such as 4-butyrolactone; organic carbonates such as diethyl carbonate, ethyl carbonate, carbonic acid Ethylene hydrocarbons; aromatic hydrocarbons such as benzene, toluene, xylene, symmetrical trimethylbenzene, ethylbenzene, styrene; aliphatic hydrocarbons such as n-pentane, n-hexane, n-octane, cyclohexane, isoundecane, Decalin, hexadecane. Preferred are ethers, especially diethyl ether, methyl-tert-butyl-ether, tetrahydrofuran and 1,4-di alkyl. The concentration of the compound of formula (I) or (II) depends, inter alia, on the reactivity and the desired reaction time. Typically, the concentration is from 0.1 mmol/l to 10 mol/l, preferably from 1 mmol/l to 1 mol/l, especially from 10 to 100 mmol/l. The reaction temperature for solution deposition is typically lower than for gas phase or mist phase deposition, typically from 20 to 150 ° C, preferably from 50 to 120 ° C, especially from 60 to 100 ° C.

If the substrate is contacted with a compound of the formula (I) or (II), deposition occurs. Generally, the deposition process can be carried out in two different ways: by heating the substrate to a decomposition temperature above or below the compound of formula (I) or (II). If the substrate is heated to a temperature higher than the decomposition temperature of the compound of the formula (I) or (II), the compound of the formula (I) or (II) is continuously decomposed on the surface of the solid substrate as long as it is more gaseous or hazy. The compound of the formula (I) or (II) may be obtained on the surface of the solid substrate. This method is typically referred to as chemical vapor deposition (CVD). Generally, when the organic material is desorbed with the metal M, an inorganic layer of a homogeneous composition such as a metal oxide or nitride is formed on the solid substrate. Typically, the solid substrate is heated to a temperature in the range of from 300 °C to 1000 °C, preferably from 350 °C to 600 °C.

Alternatively, the substrate is lower than the decomposition temperature of the metal-containing compound. Typically, the temperature of the solid substrate is equal to or slightly higher than the temperature at which the metal-containing compound is brought to a gaseous state, usually at room temperature or only slightly above room temperature. Preferably, the temperature of the substrate is 5 ° C to 40 ° C, for example 20 ° C, higher than the temperature at which the metal-containing compound becomes gaseous. Preferably, the temperature of the substrate is from room temperature to 600 ° C, more preferably from 100 to 450 ° C, such as from 150 to 350 ° C, such as 220 ° C or 280 ° C.

The compound of the formula (I) or (II) is deposited on a solid substrate by a physical adsorption or chemisorption process. Preferably, the compound of formula (I) or (II) is chemisorbed onto a solid substrate. The compound of the formula (I) or (II) can be determined by exposing a quartz microbalance having a quartz crystal of the surface of the substrate in question to a compound of the formula (I) or (II) in a gaseous or mist state. Whether to chemically adsorb to a solid substrate. The mass increase is recorded by the eigenfrequency of the quartz crystal. When the chamber in which the quartz crystal is placed is evacuated, the mass should not be lowered to the initial mass, but if chemical adsorption occurs, a single layer remains of the compound of the formula (I) or (II). X-ray photoelectron spectroscopy (XPS) signal (ISO 13424 EN-Surface chemical analysis-X) in the case where most of the compound of formula (I) or (II) is chemisorbed to a solid substrate. -ray photoelectron spectroscopy-Reporting of results of thin-film analysis; October 2013) varies due to bonding with the substrate.

If the temperature of the substrate in the process according to the invention remains below the decomposition temperature of the compound of formula (I) or (II), then typically a single layer is deposited on the solid substrate. Once the molecules of formula (I) or (II) are deposited on a solid substrate, it is generally less likely to deposit further thereon. Thus, the deposition of a compound of formula (I) or (II) on a solid substrate preferably represents a self-limiting process step. The typical layer thickness of the self-limiting deposition method step is from 0.005 to 1 nm, preferably from 0.01 to 0.5 nm, more preferably from 0.02 to 0.4 nm, especially from 0.05 to 0.2 nm. The layer thickness is typically measured by ellipsometry as described in PAS 1022 DE (Referenzverfahren zur Bestimmung von optischen und dielektrischen Materialeigenschaften sowie der Schichtdicke dunner Schichten mittels Ellipsometrie; February 2004).

It is often necessary to accumulate layers that are thicker than the layers just described. In order to achieve this in the process according to the invention, it is preferred to decompose the deposited compound of the formula (I) or (II) by removing the organic moiety, and then further depositing the formula (I) or (II) Compound. This step is preferably carried out at least twice, more preferably at least 10 times, especially at least 50 times. Usually, this process is carried out no more than 1000 times. In the context of the present invention, the removal of all organic moie means that the carbon present in the compound of formula (I) or (II) deposited does not exceed 10% by weight, more preferably does not exceed 5% by weight, especially not more than 1% by weight. Residual in the layer deposited on the solid substrate. Decomposition can be achieved in a variety of ways. The temperature of the solid substrate can be raised above the decomposition temperature.

Alternatively, the deposited compound of formula (I) or (II) may be exposed to a plasma such as an oxygen plasma, a hydrogen plasma, an ammonia plasma, or a nitrogen plasma; an oxidizing agent such as oxygen, oxygen free radicals, Ozone, nitrous oxide (N ₂ O), nitrogen oxide (NO), nitrogen dioxide (NO ₂ ) or hydrogen peroxide; ammonia or ammonia derivatives such as tert-butylamine, isopropylamine, dimethylamine, methyl Ethylamine or diethylamine; a hydrazine or a hydrazine derivative such as N,N-dimethylhydrazine; a solvent such as water, an alkane or carbon tetrachloride; or a boron compound such as borane. The choice depends on the chemical structure of the desired layer. For cerium oxide, it is preferred to use an oxidizing agent, a plasma or water, especially oxygen, water, oxygen plasma or ozone. For tantalum nitride, it is preferably ammonia, hydrazine, hydrazine derivative, nitrogen plasma or ammonia plasma. As the lanthanum boride, a boron compound is preferred. For tantalum carbide, an alkane or carbon tetrachloride is preferred. For the silicon carbide nitride, it is preferred to include a mixture of an alkane, carbon tetrachloride, ammonia and/or hydrazine.

Deposition methods that include self-limiting method steps and subsequent self-limiting reactions are commonly referred to as atomic layer deposition (ALD). The equivalent expression is molecular layer deposition (MLD) or atomic layer epitaxy (ALE). Therefore, the method according to the invention is preferably an ALD process. The ALD method is described in detail by George (Chemical Reviews 110 (2010), 111-131).

In the process according to the invention, the compound of the formula (I) or (II) is deposited on a solid substrate. The solid substrate can be any solid material. Such materials include, for example, metals, semi-metals, oxides, nitrides, and polymers. The substrate may also be a mixture of different materials. Examples of metals are tantalum, tungsten, cobalt, nickel, platinum, rhodium, palladium, manganese, aluminum, steel, zinc and copper. Examples of semi-metals are bismuth, antimony and gallium arsenide. Examples of oxides are ceria, titania, zirconia and zinc oxide. Examples of nitrides are tantalum nitride, aluminum nitride, titanium nitride, tantalum nitride, and gallium nitride. Examples of polymers are polyethylene terephthalate (PET), polyethylene naphthalene-dicarboxylic acid (PEN) and polyamine.

The solid substrate can have any shape. Such shapes include sheets, films, fibers, particles of various sizes, and substrates having grooves or other indentations. The solid substrate can have any size. If the solid substrate has a particle shape, the size of the particles may range from less than 100 nm to several centimeters, preferably from 1 μm to 1 mm. In order to prevent the particles or fibers from sticking to each other, it is preferred to keep the dynamics of the compound of the formula (I) or (II) when it is deposited thereon. This can be accomplished, for example, by agitation, by rotating a drum, or by fluidized bed techniques.

A particular advantage of the process according to the invention is that the compounds of the formula (I) or (II) are extremely versatile, so that the process parameters can vary widely. Therefore, the method according to the invention comprises both a CVD method and an ALD method.

Depending on the number of processes of the process according to the invention carried out as an ALD process, films having various thicknesses are produced. Preferably, the step of depositing a compound of the formula (I) or (II) on a solid substrate and decomposing the deposited compound of the formula (I) or (II) is carried out at least twice. This procedure can be repeated multiple times, for example 10 to 500 times, such as 50 or 100 times. Usually, this process is not repeated more than 1000 times. Ideally, the thickness of the film is proportional to the number of processes performed. However, in practice, some proportional deviations were observed for the first 30 to 50 processes. It is assumed that the surface structure irregularity of the solid substrate causes this non-proportionality.

A process according to the method of the invention can take from several milliseconds to several minutes, preferably from 0.1 second to 1 minute, especially from 1 to 10 seconds. The longer the solid substrate at a temperature lower than the decomposition temperature of the compound of the formula (I) or (II) is exposed to the compound of the formula (I) or (II), the more regular the film is formed with fewer defects. many.

A ruthenium containing film is produced in accordance with the method of the present invention. The membrane may be a single layer of a compound of formula (I), a plurality of successively deposited and decomposed layers of a compound of formula (I) or (II) or a plurality of different layers, wherein at least one of the layers is Produced by using a compound of the formula (I) or (II). The film may contain defects such as pores. However, such defects generally constitute less than half of the surface area covered by the film. The film is preferably an inorganic film. To produce an inorganic film, all organic moieties must be removed from the film as described above. The film may contain cerium oxide, cerium nitride, cerium boride, cerium carbide or a mixture such as cerium carbide nitride. The preferred film contains cerium oxide and cerium nitride. The film may have a thickness of 0.1 nm to 1 μm or more depending on the film formation method as described above. Preferably, the film has a thickness of from 0.5 to 50 nm. The film preferably has a very uniform film thickness, which means that the film thickness varies very little at different locations on the substrate, typically less than 10%, preferably less than 5%. Further, the film is preferably a conformal film on the surface of the substrate. A suitable method for determining film thickness and uniformity is XPS or ellipsometry.

The film obtained by the method according to the invention can be used in the manufacture of electronic components or in electronic components. The electronic component may have structural characteristics of various sizes, such as 10 nm to 100 μm, such as 100 nm or 1 μm. The method of forming a film for an electronic component is particularly suitable for extremely precise structures. Therefore, an electronic component having a size of less than 1 μm is preferred. Examples of electronic components are field-effect transistors (FETs), solar cells, light-emitting diodes, sensors or capacitors. In an optical device such as a light-emitting diode or a photoreceptor, the film according to the invention is used to increase the reflectance index of the layer of reflected light. An example of a sensor is an oxygen sensor, wherein, for example, if a metal oxide film is prepared, the film can act as an oxygen conductor. In a field-effect transistors out of metal oxide semiconductor (MOS-FET), the film may serve as a dielectric layer or as a diffusion barrier.

It has been surprisingly found that the method according to the invention produces a ruthenium containing film having a reduced etch rate, i.e. a film which is more stable than a ruthenium containing film in an etching process. This effect is particularly remarkable if etching is performed using hydrogen fluoride (HF) or ammonium fluoride (NH ₄ F). Such increased etch stability is an advantage in wafer production where the composite layer structure is made by depositing a film and selectively removing portions thereof, for example, by using a photoresist and a mask.

Example

Example 1

The hypersilyl potassium salt TMS3SiK*2thf (220 mg, 0.510 mmol) obtained in accordance with the procedure described by Kayser et al. in Organometallics, Vol. 21 (2002), pp. 1023-1030, in hexane (about The solution in 5 ml) was added via syringe to (pentamethylcyclopentadienyl)phosphonium tribromide obtained according to the procedure described by Jutzi et al., Chemische Berichte, Vol. 121 (1988), pp. 1299-1305 ( 99 mg, 0.246 mmol) in a stirred solution of hexane (ca. 10 ml). The color was observed to change from light yellow to pink/purple and a white solid precipitated. The reaction mixture was stirred for 30 minutes. It was filtered, concentrated to about 1 ml and allowed to crystallize at -30 °C. After storage overnight, red/purple crystals C-1 (35 mg, 0.085 mmol) were obtained. The yield was 35%. The crystal structure of C-1 is shown in Fig. 1.

¹ H NMR (400.13 MHz, 300K, benzene-d ₆ )): δ = 1.93 (s, 15H, Cp*-CH ₃ ), 0.41 (s, 27H, Si-CH ₃ ).

¹³ C{ ¹ H} NMR (100.61 MHz, 300K, benzene-d ₆ ): δ=122.45 (s, Cp*-C), 12.23 (s, Cp*-CH ₃ ), 4.94 (s, Si-CH _{3 )} ).

²⁹ Si{ ¹ H} NMR (79.49 MHz, 300 K, benzene-d ₆ ): δ=207.2 (Si:), -8.9 (Si-CH ₃ ), -110.0 (Si-TMS ₃ ).

Example 2

The solid 1,3,4,5-tetramethylimidazole-2-ylidene (8 mg, 0.064 mmol) was prepared at room temperature (according to Kuhn et al., Synthesis, Vol. 6 (1993) pp. 561-562. Add to a solution of compound C-1 (28 mg, 0.068 mmol) in C ₆ D ₆ (0.6 mL). Immediately thereafter, the color was observed to change from purple to orange/red. The NMR spectrum shows the quantitative formation of the adduct. The sample was stored at room temperature for one week to give an orange crystal of the adduct (20 mg, 0.037 mmol).

Crystals suitable for X-ray analysis were grown from C ₆ D ₆ at room temperature. The crystal structure is shown in Figure 2.

¹ H NMR (400.13 MHz, 300 K, benzene- d ₆ ): δ = 0.46 (s, 27H, Si(Si Me ₃ ) ₃ , 1.26 (s, 3H, NHC- Me ), 1.39 (s, 3H, NHC- Me ), 1.78 (br, 15H, Cp* -Me ), 3.45 (s, 3H, NHC- Me ), 3.47 (s, 3H, NHC- Me ); ²⁹ Si{ ¹ H} NMR (79.49 MHz, 300 K, Benzene- d ₆ ): δ = -9.9Si( Si Me ₃ ) ₃ , -15.7 (Cp* Si ), -134.2 ( Si (SiMe ₃ ) ₃ ).

Figure 1 shows the crystal structure of Compound C-1.

Figure 2 shows the crystal structure of Compound C-31.

Claims (14)

A method for preparing a ruthenium containing film comprising depositing a compound of the formula (I) or (II) on a solid substrate, R ₃ Si-Si---X (I) Wherein R is an alkyl group, an alkenyl group, an aryl group or a silyl group, X is an olefin group or an aromatic group which forms a π bond with a ruthenium atom, Z is a neutral ligand, and n is 1 or 2 .  The method of claim 1, wherein at least one R is a thiol group.    The method of claim 1 or 2, wherein X is a cyclopentadienyl group.    The method of claim 1 or 2, wherein the compound of the formula (I) or (II) is deposited on the solid substrate from a gas phase or a mist phase.    The method of claim 1 or 2, wherein the compound of the formula (I) or (II) is deposited from the solution onto the solid substrate.    The method of claim 1 or 2, wherein the deposited compound of the formula (I) or (II) is decomposed by removing all organic moieties.    The method of claim 6 wherein the decomposition is effected by exposure to ammonia, hydrazine, hydrazine derivatives, ammonia plasma or nitrogen plasma.    The method of claim 6 wherein the decomposing is effected by exposure to oxygen, water, ozone or oxygen plasma.    The method of claim 6, wherein the step of depositing the compound of the formula (I) or (II) on a solid substrate and decomposing the deposited compound of the formula (I) or (II) is carried out at least twice.   Use of a compound of the formula (I) or (II), wherein R is an alkyl group, an alkenyl group, an aryl group or a fluorenyl group, and X is an olefin group or an aromatic group which forms a π bond with a ruthenium atom for a film deposition method Group, R ₃ Si-Si---X (I) Z is a neutral ligand and n is 1 or 2. A compound of the formula (I) or (II) wherein R is alkyl, alkenyl, aryl or decyl, R ₃ Si-Si---X (I) X is an olefin group or an aromatic group which forms a π bond with a ruthenium atom, Z is a neutral ligand, and n is 1 or 2.  The compound of claim 11, wherein at least one R is a thiol group.    The compound of claim 11 or 12, wherein X is a cyclopentadienyl group.    The compound of claim 11 or 12, wherein Z is a cyclic carbene ligand.