Method for manufacturing a metal or metalloid-containing film

Abstract

The present invention is in the field of methods for preparing metal or semi-metal containing films. The method for preparing a metal or semi-metal containing film comprises: (a) depositing a metal or metalloid-containing compound from a gaseous state onto a solid substrate; and (b) contacting the solid substrate having the deposited metal or metalloid-containing compound with a compound of general formula (I) or (II) [Formula 1] TIFF2023502748000010.tif3477 (wherein Z is NR2, PR2, OR, SR, CR2, SiR2, X is H, R′, or NR′2, and at least one X is H; n is 1 or 2, R and R' are alkyl, alkenyl, aryl, or silyl groups. Includes:

Description

Technical Field

[0001] The present invention relates to a method for producing an inorganic metal or metalloid-containing film on a substrate, particularly in the field of atomic layer deposition.

Background Art

[0002] With the ongoing miniaturization, for example, in the semiconductor industry, the need for inorganic films on substrates is increasing, but the requirements for the quality of such films are becoming more stringent. Thin metal or metalloid films serve various purposes such as barrier layers, conductive functions, or capping layers. Several methods for producing metal or metalloid films are known. One of them is to deposit a film-forming compound from the gaseous state onto a substrate. In order to bring metal or metalloid atoms into the gaseous state at an appropriate temperature, it is necessary to provide volatile precursors, for example, by forming complexes of metals or metalloids with suitable ligands. These precursors need to be sufficiently stable against evaporation, but on the other hand, they need to have sufficient reactivity to react with the surface of the deposition.

[0003] EP 1788116 A1 discloses a method for depositing an aluminum film from a dialkylamidodihydroaluminum precursor. However, with this method, it is not possible to obtain films other than aluminum films.

[0004] In order to convert the deposited metal or metalloid complex into a metal or metalloid film, it is usually necessary to expose the deposited metal or metalloid complex to a reducing agent. Generally, hydrogen gas is used to convert the deposited metal or metalloid complex into a metal or metalloid film. Hydrogen can be used as a reducing agent for some metals, but usually, activation by plasma is required. Plasma processes are limited to low aspect ratios and may cause plasma damage to the substrate. Therefore, it is desirable to use a reducing agent that does not require plasma activation.

[0005] WO 2019 / 201692 A1 discloses a process for depositing a metal film using a bicyclic aluminum hydride compound as a reducing agent. This reducing agent generally gives good results, but in some demanding applications, a higher vapor pressure, stability, and / or reduction potential are required.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] Therefore, an object of the present invention was to provide a method for preparing an inorganic metal or metalloid-containing film with few impurities in the film. The process materials are preferably easy to handle, and in particular, it is necessary to minimize their decomposition and be able to vaporize them. Furthermore, the process materials should not decompose on the deposition surface under the process conditions, but at the same time, it is desirable that they have sufficient reactivity to participate in the surface reaction. To prevent film contamination, all reaction by-products must be volatile. Furthermore, it is necessary to be able to adjust the method so that the metal atoms or metalloid atoms in the process materials are either volatile or incorporated into the film. Furthermore, since this method has a wide range of applications, it can be applied to the production of films of various metals including electropositive metals or metalloids.

Means for Solving the Problems

[0008] These objects are achieved by (a) depositing a metal or metalloid-containing compound from a gaseous state onto a solid substrate, and (b) A step of bringing a solid substrate having a deposited metal or metalloid-containing compound into contact with a compound of general formula (I) or (II).

[0009] [Chemical Formula] (In the formula, Z is NR2, PR2, OR, SR, CR2, SiR2; X is H, R' or NR'2, and at least one X is H; n is 1 or 2; R and R' are an alkyl group, an alkenyl group, an aryl group, or a silyl group). It is achieved by a method for preparing a metal or metalloid-containing film.

[0010] The present invention further relates to a method of using a compound of general formula (I) or (II) as a reducing agent in a vapor deposition process.

Embodiments for Carrying Out the Invention

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

[0012] The method according to the present invention is suitable for the preparation of inorganic metal or metalloid-containing films. Inorganic in the context of the present invention means a material containing at least one metal or metalloid of at least 5% by mass, preferably at least 10% by mass, more preferably at least 20% by mass, particularly at least 30% by mass. Inorganic films typically contain carbon only in the form of a carbide phase, such as a mixed carbide phase like a carbonitride phase. The carbon content of carbon that is not part of the carbide phase in the inorganic film is preferably less than 5% by mass, more preferably less than 1% by mass, particularly less than 0.2% by mass. Preferred examples of inorganic metal or metalloid-containing films include metal or metalloid nitride films, metal or metalloid carbide films, metal or metalloid carbonitride films, metal or metalloid alloy films, intermetallic compound films, or films containing mixtures thereof.

[0013] The film prepared by the method according to the present invention contains a metal or a metalloid. The film can contain one metal or metalloid, or two or more metals and / or metalloids. 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 has an oxide formation energy per oxygen atom, which is more exothermic than in the case of Ni. In particular, the metal or metalloid is Ti, Ta, Mn, Mo, W, Ge, Ga, As, In, Sb, Te, Al or Si.

[0014] The solid substrate can be any solid material. These include, for example, metals, metalloids, oxides, nitrides and polymers. It is also possible for the substrate to be a mixture of different materials. Examples of metals are aluminum, steel, zinc and copper. Examples of metalloids are silicon, germanium, and 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 naphthalate-dicarboxylic acid (PEN), and polyamide.

[0015] The solid substrate can have any shape. These include sheet plates, films, fibers, particles of various sizes, and substrates having trenches or other depressions. The solid substrate can have any size. When 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. During deposition of the metal or metalloid-containing compound onto the particles or fibers, it is preferred to keep them moving to avoid the particles or fibers sticking to each other. This can be achieved, for example, by stirring, a rotating drum, or fluidized bed technology.

[0016] The method according to the invention comprises the step of (a) depositing a metal or metalloid-containing compound from the gaseous state onto a solid substrate. The metal or metalloid-containing compound contains 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 has an oxide formation energy per oxygen atom, which is more exothermic than in the case of Ni. In particular, the metal or metalloid-containing compound contains Ti, Ta, Mn, Mo, W, Ge, Ga, As, In, Sb, Te, Al or Si. One or more metal or metalloid-containing compounds can be deposited onto the surface simultaneously or successively. When one or more metal or metalloid-containing compounds are deposited on the solid substrate, it is possible for all the metal or metalloid-containing compounds to contain the same metal or metalloid, or different metals or metalloids, and preferably they contain different metals or metalloids.

[0017] Any metal or metalloid-containing compound that can be in a gaseous state is suitable. These compounds include metal or metalloid alkyls such as dimethylzinc, trimethylaluminum; metal alkoxylates such as tetramethoxysilicon, tetra-isopropoxyzirconium or tetra-isopropoxytitanium; metal or metalloid cyclopentadienyl complexes such as pentamethylcyclopentadienyl-trimethoxytitanium or di(ethylcyclopentadienyl)manganese; metal or metalloid carbenes such as tris(neopentyl)neopentylidene tantalum or bisimidazolidinylidene ruthenium chloride; metal or metalloid halides such as aluminum trichloride, tantalum pentachloride, titanium tetrachloride, molybdenum pentachloride, germanium tetrachloride, gallium trichloride, arsenic trichloride or tungsten hexachloride; carbon monoxide complexes such as hexacarbonylchromium or tetracarbonylnickel; amine complexes such as bis(tert-butylimino)bis(dimethylamide)molybdenum, bis(tert-butylimino)bis(dimethylamide)tungsten or tetrakis(dimethylamide)titanium; diketonate complexes such as tris(acetylacetonato)aluminum or bis(2,2,6,6-tetramethyl-3,5-heptanedionato)manganese. Metal or metalloid halides, particularly aluminum chloride, aluminum bromide and aluminum iodide, are preferred. The molecular weight of the metal or metalloid-containing compound is preferably 1000 g / mol or less, more preferably 800 g / mol or less, particularly 600 g / mol or less, for example 500 g / mol or less.

[0018] In the method according to the invention, when the temperature of the substrate is maintained below the decomposition temperature of the metal- or metalloid-containing compound, typically a single layer is deposited on the solid substrate. When the molecules of the metal- or metalloid-containing compound are deposited on the solid substrate, further deposition thereon is usually not preferred. Thus, the deposition of the metal- or metalloid-containing compound on the solid substrate preferably means a self-limiting process step. A typical layer thickness of the self-limiting deposition process step is from 0.01 to 1 nm, preferably from 0.02 to 0.5 nm, more preferably from 0.03 to 0.4 nm, in particular from 0.05 to 0.2 nm. Typically, the layer thickness is measured by the polarization analysis method described in PAS 1022 DE (Referenzverfahren zur Bestimmung von optischen und dielektrischen Materialeigenschaften sowie der Schichtdicke duenner Schichten mittels Ellipsometrie; February 2004).

[0019] The method according to the invention comprises the step of (b) contacting the solid substrate having the deposited metal- or metalloid-containing compound with a compound of general formula (I) or (II). Z is NR2, PR2, OR, SR, CR2, SiR2, preferably NR2, PR2, OR, SR, in particular NR2 or PR2. The Zs may all be the same or different from one another, preferably the same. X is H, R’ or NR’2, at least one X is H, preferably at least one X is H at each Al atom, in particular all Xs are H or at least one X is H at each Al atom and the other Xs are NR’2 or R’. In the context of the present invention, H includes all isotopes of hydrogen, in particular 1 H and 2 H. The latter is also called deuterium D. The exponent n can be 1 or 2 depending on Z. Typically, when Z is NR2, PR2, OR, SR, n is 2, and when Z is CR2, SiR2, n is 1.

[0020] In the compounds of general formula (I) or (II), R and R’ are an alkyl group, an alkenyl group, an aryl group, or a silyl group, preferably an alkyl group or a silyl group, particularly methyl, ethyl, iso-propyl, sec-butyl, tert-butyl, trimethylsilyl. R and R’ may be the same or different from each other. Preferably, all Rs are the same, preferably all R’s are the same, particularly all Rs and R’s are the same. Two Rs may also combine to form a ring, preferably a 3- to 8-membered ring, particularly a 5- or 6-membered ring.

[0021] The alkyl group may be straight-chain or branched. Examples of straight-chain alkyl groups include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl. Examples of branched alkyl groups include iso-propyl, iso-butyl, sec-butyl, tert-butyl, 2-methyl-pentyl, neo-pentyl, 2-ethyl-hexyl, cyclopropyl, cyclohexyl, indanyl, norbornyl. Preferably, the alkyl group is a C1-C8 alkyl group, more preferably a C1-C6 alkyl group, particularly a C1-C4 alkyl group, such as methyl, ethyl, iso-propyl or tert-butyl.

[0022] An alkenyl group contains at least one carbon-carbon double bond. The double bond can include the carbon atom to which R or R’ is attached to the remainder of the molecule, or can be located further away from the point where R or R’ is attached to the remainder of the molecule. The alkenyl group can be linear or branched. Examples of linear alkenyl groups where the double bond includes the carbon atom to which R or R’ is attached to the remainder 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 linear alkenyl groups where the double bond is located further away from the point where R or R’ is attached to the remainder 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 where the double bond includes the carbon atom to which R or R’ is attached to the remainder of the molecule include 1-propen-2-yl, 1-n-buten-2-yl, 2-buten-2-yl, cyclopentene-1-yl, cyclohexene-1-yl. Examples of branched alkenyl groups where the double bond is located further away from the point where R’ is attached to the remainder of the molecule include 2-methyl-1-buten-4-yl, cyclopentene-3-yl, cyclohexene-3-yl. Examples of alkenyl groups having two or more double bonds include 1,3-butadien-1-yl, 1,3-butadien-2-yl, cyclopentadiene-5-yl.

[0023] Aryl groups include aromatic hydrocarbons such as phenyl, naphthyl, anthracenyl, phenanthrenyl groups, and heteroaromatic groups such as pyryl, furanyl, thienyl, pyridinyl, quinolyl, benzofuryl, benzothiophenyl, thienothienyl. Some of these groups or combinations of these groups, such as biphenyl, thienophenyl or furanylthienyl are also possible. The aryl group can be substituted, for example, with a halogen such as fluoride, chloride, bromide, iodide; a pseudohalogen such as cyanide, cyanate, thiocyanate; an alcohol; an alkyl chain or an alkoxy chain. Aromatic hydrocarbons are preferred, and phenyl is more preferred.

[0024] A silyl group is a silicon atom typically having three substituents. Preferably, the silyl group has the formula SiE3, where E is, independently of one another, hydrogen, an alkyl group, an aryl group or a silyl group. All three Es may be the same, two Es may be the same and the remaining E may be different, or all three Es may be different from one another, preferably all Es are the same. The alkyl group and aryl group 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.

[0025] Preferably, the compound of general formula (I) is one of the following general formulas.

[0026]

Chemical formula

[0027] Preferred examples of the compound of general formula (I) with reference to these general formulas are shown in the following table.

[0028]

Table 1

[0029] Me represents methyl, Et represents ethyl, -(CH2)2- represents an ethylene group formed by two Rs, and -(CH2)4- represents a butylene group formed by two Rs.

[0030] The synthesis of some of the compounds of general formula (I) is described, for example, in Inorganic Chemistry, Vol. 10 (1971), pages 893 - 899 by E. Ashby et al., or in Zeitschrift fuer Naturforschung B, Vol. 63 (2008), pages 1045 - 1051 by I. Krossing et al.

[0031] Preferably, the compound of general formula (II) is one of the following general formulas.

[0032]

Chemical formula

[0033] Preferred examples of the compound of general formula (II) with reference to these general formulas are shown in the following table.

[0034]

Table 2

[0035] Me represents methyl, Et represents ethyl, -(CH2)2- represents an ethylene group formed by two Rs, and -(CH2)4- represents a butylene group formed by two Rs.

[0036] The synthesis of some of the compounds of general formula (II) is described, for example, in Zeitschrift fuer Anorganische und Allgemeine Chemie, Vol. 504 (1983), pages 67 - 76 by K. Ouzounis et al., or in Journal of the Chemical Society, Dalton Transactions: Inorganic Chemistry (1972 - 1999), 1972, pages 326 - 330 by A. Storr et al.

[0037] Preferably, R does not have a hydrogen atom at the 1 - position, i.e., R is bonded to a nitrogen or oxygen atom and thus does not have a hydrogen atom bonded to an atom in the beta - position relative to the aluminum atom. Also preferably, R' does not have a hydrogen atom at the 1 - position. More preferably, both R and R' do not have hydrogen at the 1 - position. Examples include an alkyl group having two alkyl side - groups at the 1 - position, i.e., 1,1 - dialkylalkyl, such as tert - butyl, 1,1 - dimethylpropyl; an alkyl group having two halogens at the 1 - position, such as trifluoromethyl, trichloromethyl, 1,1 - difluoroethyl; a trialkylsilyl group, such as trimethylsilyl, triethylsilyl, dimethyl - tert - butylsilyl; an aryl group, especially phenyl, or an alkyl - substituted phenyl, such as 2,6 - diisopropylphenyl, 2,4,6 - triisopropylphenyl. An alkyl group without a hydrogen atom at the 1 - position is particularly preferred.

[0038] The compound of general formula (I) or (II) preferably has a molecular weight of 1000 g / mol or less, more preferably 800 g / mol or less, even more preferably 600 g / mol or less, and particularly 500 g / mol or less.

[0039] Preferably, the compound of general formula (I) or (II) has a melting point in the range of - 80 to 125 °C, preferably - 60 to 80 °C, even more preferably - 40 to 50 °C, and particularly - 20 to 20 °C. It is advantageous if melting the compound of general formula (I) or (II) gives a transparent liquid that does not change up to the decomposition temperature.

[0040] Preferably, the compound of general formula (I) or (II) has a decomposition temperature of at least 80 °C, more preferably at least 100 °C, particularly at least 120 °C, for example at least 150 °C. In many cases, the decomposition temperature is 250 °C or lower. The compound of general formula (I) or (II) has a high vapor pressure. The vapor pressure is preferably at least 1 mbar at 200 °C, more preferably at 150 °C, particularly at 120 °C. Usually, the temperature at which the vapor pressure is 1 mbar is at least 50 °C.

[0041] To obtain the best results, the compound of general formula (I) or (II) used in the method according to the invention is used in high purity. High purity means that the substance used contains at least 90% by mass, preferably at least 95% by mass, more preferably at least 98% by mass, particularly at least 99% by mass of the compound of general formula (I) or (II) or a metal or semi-metal-containing compound. 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).

[0042] The compound of general formula (I) or (II) is brought into contact with the solid substrate in the gaseous state. It can be made gaseous, for example, by heating them to a high temperature. In any case, a temperature below the decomposition temperature of the compound of general formula (I) or (II) must be selected. The decomposition temperature is the temperature at which the original compound of general formula (I) or (II) begins to change its chemical structure and composition. The heating temperature is preferably in the range of 0 °C to 300 °C, more preferably 10 °C to 250 °C, even more preferably 20 °C to 200 °C, particularly 30 °C to 150 °C.

[0043] As another method of bringing the compound of general formula (I) or (II) into the gaseous state, there is, for example, direct liquid injection (DLI) as described in US 2009 / 0226612 A1. In this method, the compound of general formula (I) or (II) is usually dissolved in a solvent and sprayed in a carrier gas or in a vacuum. When the vapor pressure and temperature of the compound of general formula (I) or (II) are high enough and the pressure is low enough, the compound of general formula (I) or (II) will be in the gaseous state. If the compound of general formula (I) or (II) shows sufficient solubility in such solvents of at least 1 g / l, preferably at least 10 g / l, more preferably at least 100 g / l, various solvents can be used. Examples of these solvents include coordinating solvents such as tetrahydrofuran, dioxane, diethoxyethane, pyridine, or non-coordinating solvents such as hexane, heptane, benzene, toluene or xylene. Mixtures of solvents are also suitable.

[0044] Alternatively, the compound of general formula (I) or (II) can be brought into the gaseous state by direct liquid evaporation (DLE) as described, for example, by J. Yang et al. (Journal of Materials Chemistry, 2015). In this method, the compound of general formula (I) or (II) is mixed with a solvent such as a hydrocarbon like tetradecane and heated to below the boiling point of the solvent. By evaporating the solvent, the compound of general formula (I) or (II) is brought into the gaseous state. This method has the advantage that no particulate contaminants are formed on the surface.

[0045] It is preferred to bring the compound of general formula (I) or (II) into the gaseous state under reduced pressure. In this method, the process can usually be carried out at a low heating temperature which results in reducing the decomposition of the compound of general formula (I) or (II). It is also possible to use high pressure to extrude the gaseous compound of general formula (I) or (II) towards a solid substrate. For this purpose, often an inert gas such as nitrogen or argon is used as the carrier gas. The pressure is preferably from 10 bar to 10 -7 mbar, more preferably from 1 bar to 10 -3It is in the range of millibar, particularly from 1 to 0.01 millibar, for example 0.1 millibar.

[0046] Exposure of the substrate to a compound of general formula (I) or (II), or a metal or metalloid-containing compound can be carried out from milliseconds to several minutes, preferably from 0.1 second to 1 minute, particularly from 1 second to 10 seconds. The longer the time for exposing the solid substrate to a compound of general formula (I) or (II), or a metal or metalloid-containing compound at a temperature below the decomposition temperature of the compound of general formula (I) or (II), or the metal or metalloid-containing compound, the more regular the film with fewer defects is formed.

[0047] Preferably, the compound of general formula (I) or (II) acts as a reducing agent in the process of the present invention. In this case, the metal or metalloid-containing compound is deposited from the gaseous state onto the solid substrate before being brought into contact with the compound of general formula (I) or (II). The metal or metalloid-containing compound is usually reduced to a metal, a metal nitride, a metal carbide, a metal carbonitride, a metal alloy, an intermetallic compound or a mixture thereof, where the oxidation state of the metal or metalloid after reduction is lower than that before reduction. The metal film in the context of the present invention generally has a high electrical conductivity of at least 10 4 S / m, preferably at least 10 5 S / m, particularly at least 10 6 S / m and is a metal or metalloid-containing film.

[0048] The compound of general formula (I) or (II) has a low tendency to form a permanent bond with the surface of the solid substrate on which the metal or metalloid-containing compound is deposited. As a result, the metal or metalloid-containing film has a level of impurities resulting from the incorporation of reaction by-products of the compound of general formula (I) or (II). Preferably, the metal or metalloid-containing film contains, in total, less than 5% by mass, more preferably less than 1% by mass, particularly less than 0.5% by mass, for example less than 0.2% by mass of nitrogen.

[0049] A specific advantage of the method according to the invention is that the compounds of general formula (I) or (II) are very versatile, so that the process parameters can be varied over a wide range. Therefore, the method according to the invention includes both the CVD method and the ALD method.

[0050] Preferably, the series of steps including (a) and (b) is carried out at least 2 times, more preferably at least 5 times, even more preferably at least 10 times, and particularly at least 50 times. In many cases, the series of steps including (a) and (b) is carried out up to 1000 times.

[0051] Generally, each time a solid substrate is contacted with a gaseous metal or metalloid-containing compound, or a compound of general formula (I) or (II), it is preferred to purge the substrate and the surrounding apparatus with an inert gas. Preferred examples of the inert gas are nitrogen and argon. The purge can be carried out for 1 second to 1 minute, preferably 5 to 30 seconds, more preferably 10 to 25 seconds, and particularly 15 to 20 seconds.

[0052] Preferably, the temperature of the substrate is 5°C to 40°C, for example 20°C higher than the location where the metal or metalloid-containing compound is in the gaseous state. The temperature of the substrate is preferably from room temperature to 400°C, more preferably 100 to 300°C, for example 150 to 220°C.

[0053] Preferably, after depositing a metal or metalloid-containing compound on a solid substrate and before contacting the solid substrate having the deposited metal or metalloid-containing compound with a compound of general formula (I) or (II), the solid substrate having the deposited metal or metalloid-containing compound is contacted with an acid in the gas phase. Without being bound by theory, it is considered that the protonation of the ligand 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, particularly formic acid.

[0054] The method according to the present invention results in an inorganic metal or metalloid-containing film. The film can be only a single layer of metal or can be thickened, such as from 0.1 nm to 1 μm, preferably from 0.5 to 50 nm. The film may contain defects such as holes. However, these defects generally occupy less than half of the surface area covered by the film. Preferably, the film has a very uniform thickness, which means that there is little variation in the film thickness at different locations on the substrate, usually less than 10%, preferably less than 5%. Further, preferably, the film is a conformal film on the surface of the substrate. Suitable methods for determining the film thickness and uniformity are XPS or polarization analysis methods.

[0055] The film obtained by the method according to the present invention can be used in electronic devices. The electronic device can have structural features of various sizes, such as, for example, from 1 nm to 100 μm, such as 10 nm, 14 nm or 22 nm. The method of forming a film for an electronic device is particularly suitable for very fine structures. Therefore, an electronic device with a size of less than 1 μm is preferred. Examples of electronic devices include field effect transistors (FETs), charge trapping memory cells, solar cells, light emitting diodes, sensors, or capacitors. In an optical device such as a light emitting diode or a photosensor, the film obtained by the method according to the present invention helps to increase the refractive index of the light reflecting layer.

[0056] A preferred electronic device is a transistor. Preferably, the film functions as a chemical barrier metal for the transistor. A chemical barrier metal is a material that reduces the diffusion of adjacent layers while maintaining electrical connectivity.

Examples

[0057] Example 1 An atomic layer deposition process was carried out using GeBr4 and Compound IIa-1 as half-metal-containing compounds. These compounds were each placed in stainless steel cylinders and connected to a cross-flow ALD reactor having a deposition area of 1 inch in diameter and a flow rate of 5 sccm of Ar(5N) carrier gas. The base pressure was about 50 Pa. GeBr4 was heated to 55 °C and Compound IIa-1 was heated to 75 °C. 100 ALD cycles (each cycle includes a series of steps of 100 ms of GeBr4 exposure, 7.9 seconds of the first purge, 100 ms of Compound IIa-1 exposure, and 7.9 seconds of the second purge) were performed and monitored with an in-situ quartz crystal microbalance (QCM). At a reactor temperature of 160 °C to 200 °C, an average QCM frequency change of -1 Hz / cycle was observed, indicating the presence of a stable mass gain and an ALD window with a growth rate independent of temperature. GeBr4 exposure resulted in a mass increase, but the mass decreased upon subsequent exposure to Compound IIa-1. This indicates a specific reactivity of the surface formed by GeBr4 exposure with Compound IIa-1, but no deposition of Compound IIa-1 occurred.

[0058] Example 2 The same apparatus, compounds, and ALD cycles as in Example 1 were used. A blanket Si wafer substrate having either a native oxide or a 100 nm thermal oxide surface was placed in the reactor and maintained at a temperature of 160 °C. The ALD cycles described in Example 1 were performed 1000 times, and the substrate was analyzed after removal from the reactor. A layer with a thickness of about 14 nm determined by polarization analysis was deposited on the native oxide wafer substrate. The rms roughness of a similar ALD layer deposited on the thermal oxide substrate was found to be 2 nm according to AFM analysis.

[0059] Example 3 The same apparatus as in Example 1 was used. GeCl4 as a semimetal-containing compound and Compound IIa-1 were used. GeCl4 was placed in a stainless steel cylinder and kept at 0 °C during the ALD process. 100 ALD cycles (each cycle included a series of steps of 20 ms GeCl4 exposure, 7.98 s purge, 100 ms Compound IIa-1 exposure, and 7.9 s purge) were performed and monitored with an in-situ quartz crystal microbalance (QCM). At a reactor temperature of 140 °C, the average QCM frequency change was -0.4 Hz / cycle, indicating a stable mass increase. GeCl4 exposure resulted in a mass increase, but the mass decreased upon subsequent Compound IIa-1 exposure. This indicates the specific reactivity of the surface formed by GeCl4 exposure with Compound IIa-1, but no deposition of Compound IIa-1 occurred.

Claims

Claim 1 (a) depositing a metal or metalloid-containing compound from a gaseous state onto a solid substrate; and (b) contacting the solid substrate having the deposited metal or metalloid-containing compound with a compound of general formula (II) 【Chemical 1】 (In the formula, Z is NR ２ , PR ２ , OR, SR, CR ２ , SiR ２ and is X is H, R', or NR' ２ wherein at least one X is H, n is 1 or 2; R and R' are an alkyl group, an alkenyl group, an aryl group, or a silyl group) A method for preparing an inorganic metal or metalloid-containing film, comprising: The compound of general formula (II) acts as a reducing agent; The metal or metalloid-containing compound contains Ti, Ta, Mn, Mo, W, Ge, Ga, As, In, Sb, Te, Al or Si; The method, wherein the metal or metalloid-containing compound is a metal or metalloid halide. Claim 2 The method according to claim 1, wherein R is methyl, ethyl, iso-propyl, sec-butyl, tert-butyl, trimethylsilyl. Claim 3 The method according to claim 1 or 2, wherein at least one X is H for each Al atom. Claim 4 Z is NR ２ , PR ２ , OR, or SR, the method according to any one of claims 1 to 3. Claim 5 The method according to any one of claims 1 to 4, wherein the series of steps including (a) and (b) is performed at least twice. Claim 6 The method according to any one of claims 1 to 5, wherein the compound of general formula (II) has a molecular weight of 600 g / mol or less. Claim 7 The method according to any one of claims 1 to 6, wherein the compound of general formula (II) has a vapor pressure of at least 1 mbar at a temperature of 200 °C.

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