Method for producing metal or metalloid containing films

Abstract

The present invention is in the field of methods for producing inorganic films on substrates, and in particular atomic layer deposition processes. It is a method for preparing a metal or metalloid containing film, comprising the steps of: (a) depositing a metal or metalloid containing compound from a gaseous state onto a solid substrate; (b) treating a solid substrate containing a deposited metal or metalloid-containing compound with a compound of general formula (II), (III), or (IV) [Formula 1] (wherein E is Ge or Sn; R is an alkyl group, an alkenyl group, an aryl group, or a silyl group; R' is an alkyl group, an alkenyl group, an aryl group, or a silyl group; X is nothing, hydrogen, halide, alkyl group, alkylene group, aryl group, alkoxy group, aryloxy group, amino group, amidinate group, or guanidinate group; L is an alkyl group, an alkenyl group, an aryl group, or a silyl group. The present invention relates to a method comprising:

Description

[Technical field]

[0001] The present invention is in the field of methods for producing thin inorganic films on substrates, and in particular, atomic layer deposition processes. [Background technology]

[0002] With the ever-increasing miniaturization, for example in the semiconductor industry, there is an increasing need for thin inorganic films on substrates, while the requirements for the quality of such films are stringent. Thin metal or semi-metal films serve various purposes, such as barrier layers, conductive functions, or capping layers. Several methods are known for producing metal or semi-metal films. One of them is the deposition of film-forming compounds from the gaseous state onto the substrate. To bring the metal or semi-metal atoms into the gaseous state at moderate temperatures, it is necessary to provide volatile precursors, for example by complexation of the metal or semi-metal with suitable ligands. To convert the deposited metal or semi-metal complex into a metal or semi-metal film, it is usually necessary to expose the deposited metal or semi-metal complex to a reducing agent.

[0003] Hydrogen gas is typically used to convert the deposited metal complexes into metal films. Hydrogen works reasonably well as a reducing agent for relatively noble metals such as copper and silver, but does not give satisfactory results for the more electropositive metals and metalloids such as titanium, aluminum, and germanium.

[0004] WO2017 / 093265A1 discloses a method for depositing metal films using silylene as a reducing agent that, while generally giving good results, requires higher vapor pressure, stability, and / or reduction potential for some demanding applications.

[0005] WO2008 / 057616A2 discloses germanium complexes as precursors for the CVD / ALD production of metal thin films, although these complexes are not used as reducing agents.

[0006] US2008 / 108175A1 discloses a method of using germylene compounds to deposit germanium-containing films. However, the disclosed compounds are not suitable as reducing agents because of their very low stability. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] WO2017 / 093265A1 [Patent Document 2] WO2008 / 057616A2 [Patent Document 3] US2008 / 108175A1 Summary of the Invention [Problem to be solved by the invention]

[0008] It was therefore an object of the present invention to provide a reducing agent capable of reducing surface-bound metal or metalloid atoms to the metallic or metalloid state and resulting in low impurities in the metal or metalloid film. The reducing agent must be easy to handle and in particular must be able to be vaporized with as little decomposition as possible. Furthermore, the reducing agent must not decompose at the deposition surface under the process conditions, but at the same time should be sufficiently reactive to participate in the reducing surface reaction. All reaction by-products should be volatile to avoid contamination of the film. Furthermore, the process should be adjustable so that the metal or metalloid atoms are either volatile in the reducing agent or incorporated in the film. Furthermore, the reducing agent should be versatile so that it can be applied to a wide range of different metals or metalloids, including electropositive metals or metalloids. [Means for solving the problem]

[0009] These objects are directed to a method for the preparation of a metal or metalloid containing film, comprising the steps of: (a) depositing a metal or metalloid containing compound from a gas state onto a solid substrate; and (b) treating a solid substrate having a deposited metal or metalloid containing compound with a compound of general formula (II), (III) or (IV) [ka] (wherein E is Ge or Sn; R is an alkyl group, an alkenyl group, an aryl group, or a silyl group; R' is an alkyl group, an alkenyl group, an aryl group, or a silyl group; X is nothing, a hydrogen, a halide, an alkyl group, an alkylene group, an aryl group, an alkoxy group, an aryloxy group, an amino group, an amidinate group, or a guanidinate group; L is an alkyl group, an alkenyl group, an aryl group, or a silyl group; This has been achieved by a method for preparing a metal or metalloid containing film comprising: [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 shows the thermogravimetric analysis (TG) curve and the differential thermogravimetric analysis (DTG) curve of compound IIc-1. [Diagram 2] FIG. 2 shows the thermogravimetric analysis (TG) curve and the differential thermogravimetric analysis (DTG) curve of compound IIc-3. [Diagram 3] FIG. 3 shows the thermogravimetric analysis (TG) curve and the differential thermogravimetric analysis (DTG) curve of compound IIg-3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Preferred embodiments of the invention can be found in the description and in the claims. Combinations of the different embodiments are within the scope of the invention.

[0012] The method according to the invention comprises depositing a compound containing a metal or metalloid from a gaseous state onto a solid substrate. The compound containing a metal or metalloid comprises at least one metal or metalloid atom. Metals include Li, Be, Na, Mg, Al, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Bi. Metalloids include B, Si, Ge, As, Sb, Se, Te. Preferably, the metal or metalloid containing compound comprises a metal or metalloid that is more electropositive than Cu, more preferably more electropositive than Ni. In particular, the metal or metalloid containing compound comprises Ti, Ta, Mn, Mo, W, Ge, Ga, As or Al. Multiple metal or metalloid containing compounds may be deposited on a surface simultaneously or sequentially. When multiple metal or metalloid containing compounds are deposited on a solid substrate, all metal or metalloid containing compounds may comprise the same metal, metalloid or different, preferably they comprise different metals or metalloids.

[0013] Any metal or metalloid containing compound that can be put into a gaseous state is suitable. These compounds include metal or metalloid alkyls such as dimethylzinc, trimethylaluminum, metal alkoxylates such as tetramethoxysilicon, tetraisopropoxyzirconium, or tetraisopropoxytitanium, metal or metalloid cyclopentadienyl complexes such as pentamethylcyclopentadienyl-trimethoxytitanium or di(ethylcyclopentadienyl)manganese, metal or metalloid carbenes such as tris(neopentyl)neopentylidenetantalum or bisimidazolidinylideneruthenium chloride, aluminum trichloride, tantalum pentachloride, titanium tetrachloride, pentachloride, tetra ... Metal or semimetal halides such as molybdenum chloride, germanium tetrachloride, gallium trichloride, arsenic trichloride or tungsten hexachloride; carbon monoxide complexes such as chromium hexacarbonyl or nickel tetracarbonyl; amine complexes such as bis(tert-butylimino)bis(dimethylamino)molybdenum, bis(tert-butylimino)bis(dimethylamino)tungsten or tetrakis(dimethylamino)titanium; diketonate complexes such as tris(acetylacetonato)aluminum or bis(2,2,6,6-tetramethyl-3,5-heptanediate)manganese. Metal or semimetal halides are preferred, in particular aluminium chloride, aluminium bromide and aluminium iodide. The molecular weight of the compound containing the metal or semimetal is preferably at most 1000 g / mol, more preferably at most 800 g / mol, in particular at most 600 g / mol, for example at most 500 g / mol.

[0014] The solid substrate may be any solid material. These include, for example, metals, semi-metals, oxides, nitrides and polymers. The substrate may also be a mixture of different materials. Examples of metals are aluminum, steel, zinc and copper. Examples of semi-metals are silicon, germanium, gallium arsenide. Examples of oxides are silicon dioxide, titanium dioxide and zinc oxide. Examples of nitrides are silicon nitride, aluminum nitride, titanium nitride and gallium nitride. Examples of polymers are polyethylene terephthalate (PET), polyethylene naphthalenedicarboxylic acid (PEN) and polyamides.

[0015] The solid substrates can be of any shape. These include sheets, plates, films, fibers, particles of various sizes, and substrates with trenches or other depressions. The solid substrates can be of any size. If the solid substrate has a particulate shape, the size of the particles can range from less than 100 nm to several centimeters, preferably from 1 μm to 1 mm. While depositing the metal or metalloid containing compound on the particles or fibers, it is preferable to keep them moving to avoid them sticking together. This can be achieved, for example, by stirring, rotating drums or fluidized bed techniques.

[0016] According to the invention, the solid substrate having the deposited metal or metalloid containing compound is contacted with a compound represented by general formula (II), (III) or (IV). These compounds contain germanium or tin atoms in the oxidation state +2. Usually, the compound represented by general formula (II), (III) or (IV) acts as a reducing agent for the deposited metal or metalloid containing compound. The metal or metalloid containing compound is usually reduced to a metal or metalloid, a metal or metalloid nitride, a metal or metalloid carbide, a metal or metalloid carbonitride, a metal or metalloid alloy, an intermetallic compound or a mixture thereof. Thus, the method for preparing a metal or metalloid containing film is preferably a method for preparing a film comprising a metal or metalloid film, a metal or metalloid nitride film, a metal or metalloid carbide film, a metal or metalloid carbonitride film, a metal or metalloid alloy film, an intermetallic compound film or a mixture thereof. In the context of the present invention, a metal or metalloid film is a film having a high electrical conductivity, usually at least 10 4 S / m, preferably at least 10 5 S / m, especially at least 10 6 A metal or semi-metal containing film having a S / m.

[0017] The compounds represented by general formula (II), (III) or (IV) generally have a low tendency to form permanent bonds with the surface of the solid substrate containing the deposited metal or metalloid. As a result, the metal or metalloid-containing film is substantially free of contamination with reaction by-products of the compounds represented by general formula (II), (III) or (IV). Preferably, the metal or metalloid-containing film contains less than 5% by weight of nitrogen in total, more preferably less than 1% by weight, in particular less than 0.5% by weight, for example less than 0.2% by weight.

[0018] The compounds represented by general formula (II), (III) or (IV) may contain an alkyl group, an alkenyl group, an aryl group, a silyl group, a halide, an alkoxy group, an amidinate group or a guanidinate group.

[0019] The alkyl group may be linear or branched. Examples of linear alkyl groups are methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl. Examples of branched alkyl groups are isopropyl, isobutyl, sec-butyl, tert-butyl, 2-methyl-pentyl, neopentyl, 2-ethyl-hexyl, cyclopropyl, cyclohexyl, indanyl, norbornyl. Preferably, the alkyl group is a C1 to C8 alkyl group, more preferably a C1 to C6 alkyl group, in particular a C1 to C4 alkyl group such as methyl, ethyl, isopropyl or tert-butyl.

[0020] Alkenyl groups contain at least one carbon-carbon double bond. The double bond can include the carbon atom where R is attached to the rest of the molecule or can be located further away from where R is attached to the rest of the molecule. Alkenyl groups can be linear or branched. Examples of straight-chain alkenyl groups where the double bond includes the carbon atom where R is attached to the rest of the molecule include 1-ethenyl, 1-propenyl, 1-n-butenyl, 1-n-pentenyl, 1-n-hexenyl, 1-n-heptenyl, 1-n-octenyl. Examples of straight-chain alkenyl groups where the double bond is located further away from where R is attached to the rest of the molecule include 1-n-propen-3-yl, 2-buten-1-yl, 1-buten-3-yl, 1-buten-4-yl, 1-hexen-6-yl. Examples of branched alkenyl groups in which the double bond includes the carbon atom where R is attached to the remainder of the molecule include 1-propen-2-yl, 1-n-buten-2-yl, 2-buten-2-yl, cyclopenten-1-yl, and cyclohexen-1-yl. Examples of branched alkenyl groups in which the double bond is located further away from where R is attached to the remainder of the molecule include 2-methyl-1-buten-4-yl, cyclopenten-3-yl, and cyclohexen-3-yl. Examples of alkenyl groups with multiple double bonds include 1,3-butadien-1-yl, 1,3-butadien-2-yl, and cyclopentadien-5-yl.

[0021] Aryl groups include aromatic hydrocarbons such as phenyl, naphthalyl, anthracenyl, phenanthrenyl, cyclopentadienyl, indenyl, fluorenyl groups, and heteroaromatic groups such as pyrryl, furanyl, thienyl, pyridinyl, quinoyl, benzofuryl, benzothiophenyl, thienothienyl. Several of these groups or combinations of groups are possible, such as biphenyl, thienophenyl or furanylthienyl. Aryl groups can be substituted, for example, with halogens such as fluoride, chloride, bromide, iodide; with pseudohalogens such as cyanide, cyanate, thiocyanate; with alcohols; with alkyl or alkoxy chains. Aromatic hydrocarbons are preferred, and alkyl-substituted phenyl or cyclopentadienyl are more preferred.

[0022] Silyl groups are silicon atoms that usually have three substituents. Preferably, silyl groups have the formula SiZ3, where Z is independently of each other hydrogen, alkyl group, aryl group or silyl group. All three Z may be the same, two Z may be the same and the remaining Z may be different, or all three Z may be different from each other, preferably all Z are the same. Alkyl groups and aryl groups are as described above. Examples of silyl groups include SiH3, methylsilyl, trimethylsilyl, triethylsilyl, tri-n-propylsilyl, tri-iso-propylsilyl, tricyclohexylsilyl, dimethyl-tert-butylsilyl, dimethylcyclohexylsilyl, methyl-di-iso-propylsilyl, triphenylsilyl, phenylsilyl, dimethylphenylsilyl, pentamethyldisilyl.

[0023] The halide is fluoride, chloride, bromide, iodide, preferably chloride.

[0024] An alkoxy group is an oxygen atom substituted with an alkyl chain as described above. An aryloxy group is an oxygen atom substituted with an aryl group as described above.

[0025] The amino group is preferably an amine substituted with two alkyl, alkenyl, aryl, or silyl groups as described above. The substituents may be the same or different.

[0026] The amidinate group is preferably an amidinate substituted on the nitrogen atom as described above and having a carbon atom bonded to the two nitrogen atoms with an alkyl, alkenyl, aryl, or silyl group. The substituents may be the same or different from each other.

[0027] The guanidinate group is preferably a guanidinate substituted on the nitrogen atom with an alkyl, alkenyl, aryl, or silyl group as described above. The substituents may be the same or different from one another.

[0028] Preferably, R in the compounds represented by general formula (II), (III) or (IV) does not have a hydrogen atom in position 1, i.e. R does not have a hydrogen atom bonded to an atom bonded to a nitrogen atom. Examples are alkyl groups with two alkyl side groups in position 1, i.e. 1,1-dialkylalkyl, such as tert-butyl, 1,1-dimethylpropyl; alkyl groups with two halogens in position 1, such as trifluoromethyl, trichloromethyl, 1,1-difluoroethyl; trialkylsilyl groups, such as trimethylsilyl, triethylsilyl, dimethyl-tert-butylsilyl; aryl groups, especially phenyl or alkyl-substituted phenyl, such as 2,6-diisopropylphenyl, 2,4,6-triisopropylphenyl. Alkyl groups with no hydrogen atom in position 1 are particularly preferred.

[0029] Preferably, the compound represented by the general formula (II) is represented by the general formula (IIa), (IIb), (IIc), (IId), (IIe), (IIf) or (IIg) [ka] (wherein R' is an alkyl group, an alkenyl group, an aryl group or a silyl group as defined above. R' may be the same as or different from R. In the compounds represented by general formulae (IIb), (IIc), (IId), (IIe) and (IIf), R' may be the same as or different from each other.)

[0030] Some preferred examples of the compound represented by general formula (II) are shown in the following table.

[0031] [Table 1] TIFF0007657708000004.tif177132

[0032] TMS is trimethylsilyl, Me is methyl, iPr is isopropyl, tBu is tertbutyl, Cy is cyclohexyl, Ph is phenyl, Mes is mesityl, Dip is diisopropylphenyl, cp * is an abbreviation for pentamethylcyclopentadienyl.

[0033] A summary of the synthesis and properties of some compounds of general formula (II) can be found in the article by C. Jones et al., Chemical Reviews, Vol. 111 (2011), p. 354.

[0034] Preferably, the compound represented by the general formula (III) is represented by the general formula (IIIa) or (IIIb) [ka] It is a compound represented by the formula:

[0035] Some preferred examples of the compound represented by general formula (III) are shown in the table below.

[0036] [Table 2]

[0037] Preferably, the compound represented by the general formula (IV) is represented by the general formula (IVa) or (IVb) [ka] It is a compound represented by the formula:

[0038] Instead of the compound represented by the general formula (II), (III) or (IV), a compound represented by the general formula (Va) or (Vb) [ka] (wherein E is Ge or Sn; R' is an alkyl group, an alkenyl group, an aryl group, or a silyl group; X is nothing, a hydrogen, a halide, an alkyl group, an alkylene group, an aryl group, an alkoxy group, an aryloxy group, an amino group, an amidinate group, or a guanidinate group; L is nothing, an alkyl group, an alkenyl group, an aryl group, or a silyl group. The same definitions and preferred embodiments as above apply.) can be used.

[0039] Some preferred examples of the compounds represented by general formulae (Va) and (Vb) are shown in the following table.

[0040] [Table 3]

[0041] NHC stands for N,N-diisopropylimidazol-2-yl, and TIP stands for 2,4,6-triisopropylphenyl.

[0042] The synthesis of the compounds represented by the general formulae (Va) and (Vb) is described, for example, by M. Walewska et al. in Organometallics, Vol. 35 (2016) pp. 2728-2737, or by D. Nieder et al. in the Journal of the American Chemical Society, Vol. 138 (2016) pp. 13996-14005.

[0043] Some preferred examples of the compound represented by general formula (IV) are shown in the following table.

[0044] [Table 4]

[0045] The compounds represented by general formula (II), (III) or (IV) preferably have a molecular weight of 1000 g / mol or less, more preferably 800 g / mol or less, even more preferably 600 g / mol or less, especially 500 g / mol or less. The compounds represented by general formula (II), (III) or (IV) preferably have a decomposition temperature of at least 80°C, more preferably at least 100°C, especially at least 120°C, for example at least 150°C. In many cases, the decomposition temperature is 250°C or less. The compounds represented by general formula (II), (III) or (IV) have a high vapor pressure. Preferably, the vapor pressure is at least 0.1 kPa (1 mbar) at a temperature of 200°C, more preferably 150°C, especially 120°C. Usually, the temperature at which the vapor pressure is 0.1 kPa (1 mbar) is at least 50°C.

[0046] Both the metal- or metalloid-containing compound and the compound represented by general formula (II), (III) or (IV) used in the method according to the invention are used with high purity to achieve the best results.High purity means that the substance used contains at least 90% by weight, preferably at least 95% by weight, more preferably at least 98% by weight, in particular at least 99% by weight of the metal- or metalloid-containing compound or the compound represented by general formula (II), (III) or (IV).The purity can be determined by elemental analysis according to DIN 51721 (Pruefung fester Brennstoffe-Bestimmung des Gehaltes an Kohlenstoff und Wasserstoff-Verfahren nach Radmacher-Hoverath, August 2001).

[0047] The metal or metalloid containing compounds or compounds represented by general formula (II), (III) or (IV) can be deposited or contacted with the solid substrate from the gaseous state. They can be brought into the gaseous state, for example, by heating them to high temperatures. In each case, it is necessary to select a temperature that is lower than the decomposition temperature of the metal or metalloid containing compounds or compounds represented by general formula (II), (III) or (IV). In this context, the oxidation of the compounds represented by general formula (II), (III) or (IV) is not considered as decomposition. Decomposition is a reaction in which the metal or metalloid containing compounds or compounds represented by general formula (II), (III) or (IV) are converted into various different compounds that are yet to be defined. Preferably, the heating temperature is in the range of 0°C to 300°C, more preferably 10°C to 250°C, even more preferably 20°C to 200°C, in particular 30°C to 150°C.

[0048] Another method for making the metal or metalloid containing compound or the compound represented by the general formula (II), (III) or (IV) into a gaseous state is direct liquid injection (DLI), for example as described in US2009 / 0226612A1. In this method, the metal or metalloid containing compound or the compound represented by the general formula (II), (III) or (IV) is usually dissolved in a solvent and sprayed into a carrier gas or vacuum. If the vapor pressure and temperature of the metal or metalloid containing compound or the compound represented by the general formula (II), (III) or (IV) are high enough and the pressure is low enough, the metal or metalloid containing compound or the compound represented by the general formula (II), (III) or (IV) will be in a gaseous state. Various solvents can be used, provided that the metal or metalloid containing compound or the compound represented by the general formula (II), (III) or (IV) has 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 these solvents are coordinating solvents such as tetrahydrofuran, dioxane, diethoxyethane, pyridine, or non-coordinating solvents such as hexane, heptane, benzene, toluene or xylene. Solvent mixtures are also suitable.

[0049] Alternatively, the metal or metalloid containing compound or the compound represented by the general formula (II), (III) or (IV) can be brought into a gaseous state by direct liquid evaporation (DLE), for example as described by J. Yang et al. (Journal of Materials Chemistry, 2015). In this method, the metal or metalloid containing compound or the compound represented by the general formula (II), (III) or (IV) is mixed with a solvent, for example a hydrocarbon such as tetradecane, and heated below the boiling point of the solvent. Evaporation of the solvent brings the metal or metalloid containing compound or the compound represented by the general formula (II), (III) or (IV) into a gaseous state. This method has the advantage that no particulate contaminants are formed on the surface.

[0050] It is preferred to bring the metal or metalloid containing compound or the compound represented by general formula (II), (III) or (IV) into the gaseous state under reduced pressure. In this way, the method can usually be carried out at a lower heating temperature which reduces the decomposition of the metal or metalloid containing compound or the compound represented by general formula (II), (III) or (IV). It is also possible to use high pressure to push the metal or metalloid containing compound or the compound represented by general formula (II), (III) or (IV) in the gaseous state towards the solid substrate. Inert gases such as nitrogen or argon are often used as carrier gases for this purpose. Preferably, the pressure is between 1 MPa (10 bar) and 0.01 Pa (10 -7 mbar), more preferably 0.1 MPa (1 bar) to 0.1 kPa (10 -3 mbar), in particular from 0.1 to 0.001 MPa (1 to 0.01 bar), for example 10 Pa (0.1 mbar).

[0051] It is also possible to deposit or contact the metal or metalloid containing compound or the compound represented by general formula (II), (III) or (IV) from a solution onto the solid substrate. Deposition from a solution is advantageous for compounds that are not sufficiently stable to evaporation. However, the solution must be of high purity to avoid undesired contamination of the surface. Deposition from a solution usually requires a solvent that does not react with the metal or metalloid containing compound or the compound represented by general formula (II), (III) or (IV). Examples of solvents are ethers such as diethyl ether, methyl-tert-butyl ether, tetrahydrofuran, dioxane; aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, ethylbenzene, styrene; aliphatic hydrocarbons such as n-pentane, n-hexane, cyclohexane, isoundecane, decalin, hexadecane. Ethers, especially tetrahydrofuran, are preferred. The concentration of the metal or metalloid containing compound or the compound represented by general formula (II), (III) or (IV) depends, among other things, on the reactivity and the desired reaction time. Typically the concentration is between 0.1 mmol / L and 10 mol / L, preferably between 1 mmol / L and 1 mol / L, in particular between 10 and 100 mmol / L.

[0052] In the deposition process, the solid substrate can be contacted sequentially with a solution containing a metal or metalloid-containing compound and a compound represented by general formula (II), (III) or (IV). Contacting the solid substrate with the solution can be carried out in various ways, for example by dip coating or spin coating. It is often convenient to remove excess metal or metalloid-containing compound or compound represented by general formula (II), (III) or (IV), for example by rinsing with the original solvent. The reaction temperature for solution deposition is usually lower than for deposition from the gas or aerosol phase, and is usually between 20 and 150°C, preferably between 50 and 120°C, in particular between 60 and 100°C. In some cases, it is convenient to anneal the film after several deposition steps, for example by heating to a temperature between 150 and 500°C, preferably between 200 and 450°C, for 10 to 30 minutes.

[0053] Deposition of a metal or metalloid containing compound occurs when a substrate is contacted with a metal or metalloid containing compound. In general, the deposition process can be carried out in two different ways: heating the substrate above or below the decomposition temperature of the metal or metalloid containing compound. When the substrate is heated above the decomposition temperature of the metal or metalloid containing compound, the metal or metalloid containing compound continuously decomposes on the surface of the solid substrate as more metal or metalloid containing compounds in gaseous state reach the surface of the solid substrate. This process is usually called chemical vapor deposition (CVD). Usually, an inorganic layer of homogeneous composition, e.g., a metal or metalloid oxide or nitride, is formed on the solid substrate when the organic material desorbs from the metal or metalloid M. This inorganic layer is then converted into a metal or metalloid layer by contacting it with a compound represented by general formula (II), (III) or (IV). Typically, the solid substrate is heated to a temperature in the range of 300 to 1000°C, preferably in the range of 350 to 600°C.

[0054] Alternatively, the substrate is below the decomposition temperature of the metal or metalloid containing compound. Typically, the solid substrate is at a temperature equal to or slightly above the temperature at which the metal or metalloid containing compound becomes gaseous, often at room temperature or slightly above. Preferably, the substrate temperature is 5° C. to 40° C. higher than the temperature at which the metal or metalloid containing compound becomes gaseous, for example 20° C. Preferably, the substrate temperature is from room temperature to 400° C., more preferably from 100 to 300° C., for example from 150 to 220° C.

[0055] The deposition of a metal- or metalloid-containing compound on a solid substrate is either a physisorption or chemisorption process. Preferably, the metal- or metalloid-containing compound is chemisorbed on the solid substrate. Whether a metal- or metalloid-containing compound chemisorbs on a solid substrate can be determined by exposing a quartz crystal microbalance containing a quartz crystal with the surface of the substrate in question to the gaseous state metal- or metalloid-containing compound. The increase in mass is recorded by the characteristic frequency of the quartz crystal. Evacuation of the chamber in which the quartz crystal is located should not reduce the mass to the initial mass, but if chemisorption has occurred, up to one, two, or three monolayers of residual metal- or metalloid-containing compound will remain. In most cases where chemisorption of a metal- or metalloid-containing compound on a solid substrate occurs, the X-ray photoelectron spectroscopy (XPS) signal of M (ISO 13424 EN - Surface chemical analysis - X-ray photoelectron spectroscopy - Reporting of results of thin-film analysis; October 2013) changes due to bond formation to the substrate.

[0056] When the temperature of the substrate in the method according to the invention is kept below the decomposition temperature of the metal- or metalloid-containing compound, typically a monolayer is deposited on the solid substrate. Once molecules of the metal- or metalloid-containing compound are deposited on the solid substrate, they are usually unlikely to be further deposited thereon. Thus, the deposition of the metal- or metalloid-containing compound on the solid substrate preferably represents a self-limiting process step. Typical layer thicknesses of self-limiting deposition process steps are 0.01 to 1 nm, preferably 0.02 to 0.5 nm, more preferably 0.03 to 0.4 nm, in particular 0.05 to 0.2 nm. The layer thickness is typically measured by ellipsometry as described in PAS 1022 DE (References zur Bestimmung von optischen und dielektrischen Materialeigenschaften sowie der Schichtdicke duenner Schichten mittels Ellipsometrie; February 2004).

[0057] A deposition process that includes a self-limiting process step followed by a self-limiting reaction is often called atomic layer deposition (ALD). Equivalent expressions are molecular layer deposition (MLD) or atomic layer epitaxy (ALE). The method according to the invention is therefore preferably an ALD process. The ALD process is described in detail by George (Chemical Reviews 110 (2010), 111-131).

[0058] A particular advantage of the method according to the invention is that the compounds of general formula (II), (III) or (IV) are very versatile and therefore the process parameters can be varied widely. Thus, the method according to the invention includes both CVD and ALD processes.

[0059] Preferably, after deposition of the metal or metalloid-containing compound on the solid substrate, the solid substrate containing the deposited metal or metalloid-containing compound is contacted with an acid in the gas phase before contacting the solid substrate containing the deposited metal or metalloid-containing compound with a reducing agent. Without being bound by theory, it is believed that protonation of the ligands of the metal or metalloid-containing compound promotes its decomposition and reduction. Suitable acids include hydrochloric acid and carboxylic acids, preferably carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, or trifluoroacetic acid, especially formic acid.

[0060] In many cases, it is desirable to build thicker layers than those just described. To achieve this, the process comprising (a) and (b), which can be considered as one ALD cycle, is preferably carried out at least twice, more preferably at least 10 times, and especially at least 50 times. Typically, the process comprising (a) and (b) is carried out no more than 1000 times.

[0061] Deposition of the metal or metalloid containing compound or contacting it with the reducing agent can take from milliseconds to minutes, preferably from 0.1 seconds to 1 minute, in particular from 1 to 10 seconds. The longer the solid substrate is exposed to the metal or metalloid containing compound at a temperature below the decomposition temperature of the metal or metalloid containing compound, the less defects and the more ordered the film will be. The same is true when the deposited metal or metalloid containing compound is contacted with a reducing agent.

[0062] The method according to the invention produces a metallic or semi-metallic film. The film may be only a single monolayer of the metal or semi-metal or may be thicker, such as 0.1 nm to 1 μm, preferably 0.5 to 50 nm. The film may contain defects such as holes. However, these defects generally constitute less than half of the surface area covered by the film. The film preferably has a very uniform film thickness, meaning that the film thickness at different locations on the substrate varies very little, usually less than 10%, preferably less than 5%. Furthermore, the film is preferably a conformal film on the surface of the substrate. Suitable methods for determining the film thickness and uniformity are XPS or ellipsometry.

[0063] The film obtained by the method of the present invention can be used in electronic devices. Electronic devices can have structural features of various sizes, for example, from 100 nm to 100 μm. The method of forming the film for electronic devices is particularly suitable for very fine structures. Electronic devices having a size of less than 1 μm are therefore preferred. Examples of electronic devices include field effect transistors (FETs), solar cells, light-emitting diodes, sensors or capacitors. In optical devices such as light-emitting diodes or light sensors, the film obtained by the method of the present invention is useful for increasing the refractive index of the layer that reflects light.

[0064] A preferred electronic device is a transistor. Preferably, the film functions as a chemical barrier metal or metalloid in a transistor. A chemical barrier metal or metalloid is a material that reduces diffusion of adjacent layers while maintaining electrical connectivity. EXAMPLES

[0065] All manipulations were performed under a protective atmosphere of argon (purity >99.999%) using Schlenk techniques or in a glove box. Dioxane was refluxed with Na / benzophenone and distilled before use. Deuterated solvents (C6D6) were dried over potassium and distilled under argon. NMR spectra were recorded on a Bruker Avance III 300 MHz spectrometer. High-resolution mass spectra (MS-CI) were recorded on a Finnigan 950S mass spectrometer (methane, 4.7 kV). Germanium dichloride adducts with dioxane were purchased from ABCR and used without further purification. The starting diamine MeN(CH2CH2CH2N(H)SiMe3)2 and its dilithium salt were prepared according to the procedure in: Thomas A. Lowes, Benjamin D. Ward, Robert A. Whannel, Stuart R. Dubberley, Philip Mountford, Chemical Communications, 2005, pp. 113-115.

[0066] Synthesis of IIg-3

[0067] [ka]

[0068] Germanium dichloride adduct GeCl2 with dioxane in dioxane (~30 mL) * A solution of dioxane (1.27 g, 5.48 mmol) was added dropwise to a pre-cooled (15 °C) solution of lithium 2,2,7,12,12-pentamethyl-3,7,11-triaza-2,12-disilatridecane-3,11-diide (1.66 g, 5.50 mmol) in ~40 mL of dioxane. The reaction mixture was stirred at room temperature overnight to give a yellowish solution. All volatiles were removed in vacuo. The remaining residue was extracted with hexane (~70 mL) and filtered. The solvent was removed in vacuo. The remaining oil was kept under vacuum (4 Pa (4 * 10 -2C. for 20 min at 60-95.degree. C. bath temperature) to give the residual compound IIg-3 (1.77 g, 4.91 mmol) as a yellowish oil.

[0069] 1 H NMR (300.13MHz, 300K, C6D6): δ=3.38(m, 2H, CH2) 3.08(m, 2H, CH2), 2.72(br, 2H, CH 2), 1.87(s, 3H, NCH3), 1.86(br, 2H, CH2), 1.25(m, 4H, CH2), 0.31(s, 18H, Si(CH3)3) 13 C{ 1 H}NMR (75.47MHz, 300K, C6D6): δ=57.50, 43.59, 43.54(NCH2, NCH3), 27.80(NCH2CH2), 1.46(Si(CH3)3) HR MS (CI, m / z): [M+H] + is C 13 H 34 Calculated against N3GeSi2362.1503, we found 362.1500.

Claims

1. A method for preparing a metal or metalloid containing film by a CVD or ALD process, comprising: (a) depositing a metal or metalloid containing compound from a gas state onto a solid substrate; and (b) treating a solid substrate having a deposited metal or metalloid containing compound with a compound represented by general formula (IIa), (IIc), (IIf) or (IIg) 【Chemistry 1】 (In the formula, E is Ge or Sn; R is an alkyl group, an alkenyl group, an aryl group, or a silyl group; R' is an alkyl group, an alkenyl group, an aryl group, or a silyl group; and X is nothing, a hydrogen, an alkyl group, an alkylene group, an aryl group, an alkoxy group, an aryloxy group, an amino group, an amidinate group, or a guanidinate group. The preparation method according to the present invention comprises the steps of:

2. 2. The method of claim 1, wherein R does not have a hydrogen atom at the 1 position.

3. 3. The method according to claim 1 or 2, wherein the compound of general formula (IIa), (IIc), (IIf) or (IIg) has a molecular weight of less than or equal to 600 g / mol.

4. 4. The method according to claim 1, wherein the compound of general formula (IIa), (IIc), (IIf) or (IIg) has a vapour pressure of at least 1 mbar at a temperature of 200°C.

5. 5. The method of claim 1, wherein (a) and (b) are performed at least twice in succession.

6. 6. The method of any one of claims 1 to 5, wherein the compound containing a metal or metalloid comprises Ti, Ta, Mn, Mo, W, Ge, Ga, As or Al.

7. 7. The method of claim 1, wherein the compound containing a metal or metalloid is a metal or metalloid halide.

8. 8. The method of any one of claims 1 to 7, wherein the temperature does not exceed 350°C.

9. The method according to any one of claims 1 to 8, wherein the compound containing a metal or metalloid and the compound represented by general formula (IIa), (IIc), (IIf) or (IIg) are converted into a gaseous state by heating to a temperature of 20°C to 200°C.

10. 10. The method of any one of claims 1 to 9, wherein the metal or metalloid containing film is a metal or metalloid film, a metal or metalloid nitride film, a metal or metalloid carbide film, a metal or metalloid carbonitride film, a metal or metalloid alloy film, or an intermetallic compound film.

11. The metal or metalloid containing film is at least 10 ４ 11. The method according to claim 1, having a conductivity of S / m.

12. 12. The method of any one of claims 1 to 11, wherein the metal or metalloid containing film comprises less than 5% total nitrogen by weight.

13. The following formula (IIg): 【Chemistry 2】 (In the formula, E is Ge or Sn; R is an alkyl group, an alkenyl group, an aryl group, or a silyl group. A reducing agent which is a compound represented by the formula:

14. The method for producing the reducing agent according to claim 13, which uses an adduct of germanium dichloride and dioxane.

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