WO2023219428A1 - Precursor compound for forming metal film and metal film using same - Google Patents

Abstract

The present invention relates to a precursor compound, containing molybdenum, for forming a metal film and a metal film using same, wherein the precursor compound has excellent reactivity with a substrate or a reactive gas and high volatility and can form a metal thin film with a low content of impurities in a wide temperature range, especially, even at a low temperature.

Description

Precursor compound for forming metal film and metal film using the same

The present invention relates to a precursor compound for forming a metal film containing molybdenum and a metal film using the same.

In the manufacture of microelectronic devices such as RAM (random access memory), flash memory, and logic chips, thin film transistor (TFT) devices of flat panel displays, and semiconductor devices of solar cells, metal-containing It is necessary to form a thin film (hereinafter simply referred to as a 'metal film' if necessary). For example, when a deposition process is performed while reacting a metal precursor compound with a reaction gas _containing hydrogen, nitrogen, or oxygen, a metal thin film (M, _M is a metal) or a metal oxide thin film (M (indicates the number) or a metal nitride (M _x N _y ) thin film can be formed. The metal-containing thin film formed in this way can be used as a wiring, an electrode, an oxidation prevention film, a dielectric film, an etching stopper layer in an etching process, a film to prevent the increase in variation in gate electrode resistance or the diffusion of dopants, TMDCs or TMDs (Transition metal dichalcogenides), etc. . As the deposition process, methods such as sputtering, CVD (chemical vapor deposition), and ALD (atomic layer deposition) are commonly used.

As metal precursor compounds used to form metal films, metal chloride compounds, metal alkoxide compounds, metal-alkyl compounds, metal-amino compounds, etc. of various structures are used. However, when using a metal chloride compound precursor, it is difficult to completely remove chloride generated as a by-product, and the generated chloride may be re-adsorbed to the metal film, deteriorating the characteristics of the metal film.

Meanwhile, with the miniaturization and high integration of semiconductor devices, there is a limit to the miniaturization of semiconductor devices using only a planar structure, so research on semiconductor devices with a multi-layer structure has recently been actively conducted. When forming a metal thin film in the manufacture of such a multi-layer structure device, high film uniformity and excellent conformal step coverage are required. Accordingly, there is a need for the development of a highly volatile liquid metal precursor and related processes that enable precise process control in the manufacture of multilayer devices.

Accordingly, the present invention provides a precursor compound for forming a metal film containing molybdenum, which is easy to remove reaction by-products and can form a metal thin film with a low impurity content in a wide temperature range, and a metal film using the same.

One embodiment of the invention provides a precursor compound for forming a metal film containing at least one member selected from the group consisting of compounds represented by the following formulas 1 and 2:

[Formula 1]

[Formula 2]

In Formulas 1 and 2,

M is each independently a transition metal selected from the group consisting of Cr, Mo, W, V, Nb and Ta,

R ₁ is each independently hydrogen, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted linear or branched, saturated or unsaturated alkoxy group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group having 5 carbon atoms. an aryl group having 5 to 20 carbon atoms, a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms, a substituted or unsubstituted aralkoxy group having 5 to 30 carbon atoms, a substituted or unsubstituted amino group, or isomers thereof,

R ₂ and R ₃ are each independently hydrogen, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted linear or branched, saturated or unsaturated alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkyl group. A linear or branched, saturated or unsaturated alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 5 to 20 carbon atoms, a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms, or a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms. to 30 aralkoxy groups, substituted or unsubstituted amino groups, or isomers thereof.

In addition, one embodiment of the invention according to the present specification provides a metal film derived from one or more precursor compounds for forming a metal film selected from the group consisting of compounds represented by Formulas 1 and 2.

The metal precursor compound according to the present invention has excellent reactivity with a substrate or reaction gas, has high volatility, and can form a metal thin film with low impurity content even over a wide temperature range, especially at low temperatures. More specifically, the present invention uses atomic layer deposition, which is considered the most precise of the existing thin film formation methods, to create a metal film, so even in the case of a substrate with a large aspect ratio, the process temperature is controlled to produce a very uniform metal film. A film can be formed.

In addition, when using existing metal chloride compound precursors, it is difficult to remove chloride generated as a by-product, and it is difficult to maintain constant process conditions due to the solid precursor, especially the precursor vapor pressure, but this technology maintains stable process conditions and maintains high A uniform metal film can be formed based on volatility and reactivity, resulting in cost and quality advantages.

Figure 1 graphically shows the results of TGA remaining amount (@400°C) according to temperature in Examples 2, 3, 7, and 9.

Figure 2 shows a transmission electron microscope (TEM) image of the MoN metal film of Example 9.

Hereinafter, the present invention will be described in more detail. Terms or words used in this specification and claims should not be construed as limited to their common or dictionary meanings, and the inventor may appropriately define the concept of terms in order to explain his or her invention in the best way. It must be interpreted with meaning and concept consistent with the technical idea of the present invention based on the principle that it is.

In addition, the meaning of "comprising" as used in the specification of the present invention specifies a specific characteristic, area, integer, step, operation, element and/or component, and other characteristics, area, integer, step, operation, element and/or It does not exclude the presence or addition of ingredients.

Hereinafter, a molybdenum-containing compound and a molybdenum-containing metal film using the same according to an embodiment of the invention will be described in detail.

The present invention relates to a novel metal precursor compound and a metal film using the same. More specifically, examples of the present invention provide a metal precursor compound from which reaction by-products can be easily removed and a metal film using the same. More specifically, examples of the present invention provide a metal precursor compound capable of forming a metal thin film with a low impurity content even in a wide temperature range, especially at low temperatures, and a metal film using the same.

In order to achieve the above object, according to one embodiment of the invention, a precursor compound for forming a metal film is provided including at least one member selected from the group consisting of compounds represented by the following formulas 1 and 2:

[Formula 1]

[Formula 2]

In Formulas 1 and 2, M is each independently a transition metal selected from the group consisting of Cr, Mo, W, V, Nb, and Ta,

R ₁ is each independently hydrogen, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted linear or branched, saturated or unsaturated alkoxy group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group having 5 carbon atoms. an aryl group having 5 to 20 carbon atoms, a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms, a substituted or unsubstituted aralkoxy group having 5 to 30 carbon atoms, a substituted or unsubstituted amino group, or isomers thereof,

R ₂ and R ₃ are each independently hydrogen, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted linear or branched, saturated or unsaturated alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkyl group. A linear or branched, saturated or unsaturated alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 5 to 20 carbon atoms, a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms, or a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms. to 30 aralkoxy groups, substituted or unsubstituted amino groups, or isomers thereof.

In the present invention, at least one of the compounds represented by Formulas 1 and 2 is used as a precursor for forming a metal film, for excellent reactivity and volatility when forming a metal film due to a phosphorus ligand or As ligand of a specific structure included in the structure. As the resistivity is improved, the electrical properties of the thin film can be improved compared to before.

Specifically, the compound selected from the group consisting of compounds represented by the formulas 1 and 2 includes an alkyl, alkoxy, or amine group in the phosphorus ligand or As ligand structure, and thus has excellent electrical properties, and especially exhibits a liquid state at 25 ° C. or lower. You can.

At this time, if the precursor compound contains only a halogen or alkyl group in the phosphorus ligand or As ligand, chloride and carbon by-products are generated during the metal thin film deposition process, which may cause problems with impurities in the metal film.

In particular, when using an existing metal chloride compound precursor, there are problems such as difficulty in removing chloride generated as a reaction by-product and difficulty in maintaining constant process conditions, especially precursor vapor pressure, due to the solid precursor.

In contrast, the precursor compound of the present invention having the specific phosphorus ligand or As ligand structure described above can maintain stable process conditions by preventing the generation of reaction by-products. Additionally, the precursor compound can form a uniform metal film based on its high volatility and reactivity, thereby providing cost and quality advantages.

In addition, while conventional compounds generally used as precursors when forming metal films (i.e., metal thin films) are mainly solid, the precursor compounds of the present invention may be liquid compounds at room temperature of 25°C or less, or 15 to 25°C. . Accordingly, in the present invention, since deposition can be carried out by vaporizing the liquid phase, it can provide advantageous effects in terms of the deposition process and electrical characteristics compared to the conventional solid precursor compound.

These compounds may be precursor compounds for forming a metal film. Additionally, the compound may be a compound used as a precursor for semiconductors.

According to a preferred embodiment of the invention, the precursor compound may be a compound including a phosphorus ligand represented by Formula 1 among compounds selected from the group consisting of compounds represented by Formulas 1 and 2. In this case, one or more substituents of the compound selected from the group consisting of compounds represented by Formula 1 may be most effective if each independently contains an alkoxy or amine group on the phosphorus ligand.

More specifically, in Formulas 1 and 2, R ₁ is each independently a substituted or unsubstituted linear or branched, saturated or unsaturated alkoxy group having 1 to 10 carbon atoms, or a substituted or unsubstituted amino group, R ₂ and R ₃ are each independently a substituted or unsubstituted linear or branched, saturated or unsaturated alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted linear or branched, saturated or unsaturated alkoxy group having 1 to 6 carbon atoms. It may be a group, or a substituted or unsubstituted amino group.

Therefore, according to one embodiment, when the R ₁ to R ₃ each independently include an amino group, the amino group may be substituted or unsubstituted, for example, when it has a substituent, it has 1 to 10 carbon atoms and 1 to 10 carbon atoms. It may contain 10 linear or branched, saturated or unsaturated hydrocarbons.

In addition, R ₁ is each independently a substituted or unsubstituted linear or branched, saturated or unsaturated alkoxy group having 2 to 10 carbon atoms, or a substituted or unsubstituted amino group, and R ₂ and R ₃ are each independently A substituted or unsubstituted linear or branched, saturated or unsaturated alkyl group having 2 to 10 carbon atoms, a substituted or unsubstituted linear or branched, saturated or unsaturated alkoxy group having 1 to 6 carbon atoms, or a substituted or unsubstituted amino group. It may be phosphorus or a compound.

At least one of R ₁ to R ₃ may be a substituted or unsubstituted saturated or unsaturated alkoxy group having 1 to 10 carbon atoms.

At least one of R ₁ to R ₃ may be a substituted or unsubstituted saturated or unsaturated alkoxy group having 2 to 10 carbon atoms.

At least one of R ₁ to R ₃ may be a substituted or unsubstituted saturated or unsaturated alkoxy group having 3 to 4 carbon atoms.

At least one of R ₁ to R ₃ may be a substituted or unsubstituted saturated or unsaturated alkoxy group having 3 carbon atoms.

At least one of R ₁ to R ₃ may be a substituted or unsubstituted alkoxy group having a saturated or unsaturated branched structure of 3 to 6 carbon atoms.

R ₁ to R ₃ may be substituted or unsubstituted saturated or unsaturated alkoxy groups having 1 to 6 carbon atoms having the same structure. When R ₁ to R ₃ are alkoxy having the same structure, a better effect can be achieved than when they are not.

R ₁ and R ₂ are substituted or unsubstituted saturated or unsaturated alkoxy groups having 1 to 6 carbon atoms having the same structure, and R ₃ is a substituted or unsubstituted alkoxy group having different structures from R ₁ and R ₂ It may be a compound containing 3 to 6 saturated or unsaturated alkoxy groups. In the present specification, better effects can be achieved when R ₁ to R ₃ are all different alkoxy groups.

R ₁ to R ₃ may be compounds having the same structure.

R ₁ and R ₂ may have the same chemical formula, and R ₃ may be a compound that has a different chemical formula independently from R ₁ and R ₂ . It may have a better effect than when R ₁ to R ₃ all have different chemical formulas.

In addition, when the precursor compound contains an alkoxy group at any one or more of R ₁ to R ₃ of the phosphorus ligand, the case where it contains a branched alkoxy group rather than a linear alkoxy group has excellent thermal stability at the decomposition temperature and excellent volatility, thereby improving electrical properties. can be further improved. In addition, the branched alkoxy structure has a larger packing size than the linear alkoxy structure, which reduces the viscosity, which can be advantageous in the deposition process.

In addition, the precursor compound of the present invention can significantly improve thermal stability and electrical properties compared to the conventional linear structure containing halogen in the phosphorus ligand.

According to a preferred embodiment of the invention, the precursor compound may be any one selected from compounds having the following structures.

The compound may have a TGA residual amount (@400°C) of 10% or less.

The remaining amount of TGA was determined by measuring the mass loss rate while raising the temperature to 400°C for the Mo precursor compound using thermogravimetric analysis under inert conditions, as in the method of the experimental example described below, and measuring the remaining amount of TGA (@400°C) according to the weight loss curve. ) can be measured by calculating.

Additionally, the compound may be a compound with a purity of 99% or more.

Additionally, in one embodiment of the invention according to the present specification, a metal film derived from the above compound may be provided.

Specifically, a metal film derived from one or more precursor compounds for forming a metal film selected from the group consisting of compounds represented by the following formulas 1 and 2 may be provided:

[Formula 1]

[Formula 2]

In Formulas 1 and 2,

M is each independently a transition metal selected from the group consisting of Cr, Mo, W, V, Nb and Ta,

R ₁ is each independently hydrogen, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted linear or branched, saturated or unsaturated alkoxy group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group having 5 carbon atoms. an aryl group having 5 to 20 carbon atoms, a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms, a substituted or unsubstituted aralkoxy group having 5 to 30 carbon atoms, a substituted or unsubstituted amino group, or isomers thereof,

R ₂ and R ₃ are each independently hydrogen, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted linear or branched, saturated or unsaturated alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkyl group. A linear or branched, saturated or unsaturated alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 5 to 20 carbon atoms, a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms, or a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms. to 30 aralkoxy groups, substituted or unsubstituted amino groups, or isomers thereof.

The metal film is a thin film containing molybdenum and may be a single film or an alloy. The type is not limited and may be a thin film containing molybdenum well known in the field. Additionally, the metal film may be a single film or an alloy that can be changed depending on the type of gas input. For example, the metal film may refer to a film formed of a single metal (Mo) as well as a film containing elements other than metal (MoN, MoO2).

According to one embodiment of the invention, in this specification, the metal film may be a film (thin film) containing a metal such as Mo, MoN, or MoO ₂ . Additionally, the metal may be molybdenum. However, the metal film is not limited to these and may change depending on the type of gas input. That is, the metal film may be formed containing a metal such as Mo, MoN, or MoO ₂ depending on the type of gas input.

According to another preferred embodiment, the metal film may be a Mo thin film, a MoN thin film, or a MoO ₂ thin film.

When the metal film is a Mo thin film, the metal film may contain more than 50% by weight of Mo, less than 25% by weight of carbon, less than 35% by weight of oxygen, and residual amounts of impurities when measuring the XPS surface component after forming the Mo thin film. Specifically, The Mo content may be 50% by weight or more, or 55% by weight or more.

The remaining amount of impurities may be 10 wt% or less, 5 wt% or less, 1 wt% or less, 0.1 wt% or less, 0.09 wt% or less, or 0 wt%. The impurities may include P and As. The P and As are parts that fall off during the metal film formation process on the substrate, and may refer to parts that may remain on the substrate as impurities if some parts do not fall off during the process. In one example, the impurities include 5% by weight or less of P and 5% by weight of As, or less than 2.5% by weight of P and 2.5% by weight or less, or less than 0.5% by weight of P and 0.5% by weight or less, or less than 0.5% by weight of P, and As may be less than 0.05% by weight.

When the metal film is a MoN thin film, the metal film contains more than 20% by weight of Mo, more than 25% by weight of nitrogen, less than 25% by weight of carbon, less than 30% by weight of oxygen, and residual amounts of impurities when measuring the XPS surface component after forming the MoN thin film. can do. The Mo content in the MoN thin film may be 25% by weight or more or 30% by weight or more.

The impurities may be 10% by weight or less, 5% by weight or less, 1% by weight or less, 0.1% by weight or less, and 0.09% by weight or less. The impurities may include P and As. The P and As are parts that fall off during the metal film formation process on the substrate, and may refer to parts that may remain on the substrate as impurities if some parts do not fall off during the process. In one example, the impurities include 5% by weight or less of P and 5% by weight of As, or less than 2.5% by weight of P and 2.5% by weight or less, or less than 0.5% by weight of P and 0.5% by weight or less, or less than 0.5% by weight of P, and As may be less than 0.05% by weight.

At this time, in this specification, the surface component content can be measured according to a method well known in the field through XPS (X-ray photoelectron spectroscopy, ThermoFisher Scientific NEXSA) depth profile analysis. In addition, the surface component content refers to the case where the total content of components contained on the surface of the metal film is 100% by weight. Therefore, the upper limit of each component may be a content that does not exceed 100% by weight, and the sum of each component satisfies 100% by weight.

For example, when the metal film is a Mo thin film, when measuring the XPS surface component after forming the Mo thin film, the metal film contains 50% by weight to 60% by weight of Mo, 15% to 25% by weight of carbon, and 20% by weight of oxygen. It may contain up to 35% by weight and the remaining amount of impurities.

In addition, when the metal film is a MoN thin film, when measuring the XPS surface component after forming the MoN thin film, the metal film contains 20% by weight to 35% by weight of Mo, 25% by weight to 45% by weight of nitrogen, and 10% by weight to 25% of carbon. % or less, 15% to 30% by weight of oxygen, and the remaining amount of impurities.

The remaining amount of impurities means that when the total of the components is less than 100% by weight, the remaining amount is taken up to 100% by weight. Accordingly, the remaining impurity content may vary depending on the total content of the components. For example, if no impurities are present, the remaining amount of impurities may be 0% by weight. In addition, when impurities are present, the remaining impurities may be present in an amount of more than 0% by weight and less than 10% by weight, but the remaining impurity content may vary depending on the total content of the above components.

This metal film is formed by using at least one selected from the group consisting of Formulas 1 and 2 as a precursor, so that compared to using existing precursors or precursors containing halogen, the impurity content in the thin film is small, resulting in excellent electrical properties. can be provided.

Additionally, the method of forming a metal film according to the present specification may be provided including the step of depositing the compound on a substrate, and the method is not significantly limited.

In the method of forming a metal film according to an embodiment of the invention, the step of depositing a compound selected from the group consisting of the compounds represented by Formulas 1 and 2 on a substrate includes the compounds represented by Formulas 1 and 2. Compounds selected from the group consisting of; and forming a metal film on the substrate using at least one reactant selected from a reducing reactant, an oxygen source, a nitrogen source, a sulfur source, a selenium source, and a tellurium source.

Specifically, as a method of forming the metal film, various methods using gas-phase reaction, such as sputtering, CVD (Chemical Vapor Deposition), and ALD (Atomic Layer Deposition), may be used. It may include, but is not limited to, continuous or pulse injection processes, liquid injection processes, light-assisted processes, and plasma-assisted processes.

In the metal film deposition method of the present invention, 1) the reducing reactant for metal formation includes hydrogen, nitrogen, ammonia, borane, diborane, triborane, silane, disilane, trisilane, or plasma thereof. One or more selected substances may be used, and mixtures thereof may be selected from the group consisting of them.

2) The oxygen source may be one or more selected from the group consisting of oxygen, hydrogen peroxide, ozone, nitrogen monoxide, water, or plasma thereof, and may be selected from the group consisting of mixtures thereof.

3) As the nitrogen source, one or more selected from the group consisting of ammonia, hydrazine, alkylhydrazine, dialkylhydrazine, nitrogen, or plasma thereof may be used, and mixtures thereof may be used.

4) Oxygen and nitrogen sources can be used together to form an oxynitride film.

5) As the sulfur source, one or more selected from the group consisting of hydrogen sulfide, dimethyl sulfide, dimethyl disulfide, or plasma thereof may be used, and mixtures thereof may be used.

6) As a selenium source, ((CH ₃ ) ₃ Si) ₂ Se or their plasma can be used.

7) As the tellurium source, one or more selected from the group of Te and _FeTe may be used, and mixtures thereof may be used.

In the metal film formation method of this embodiment, deposition equipment such as ALD or CVD, which is a vapor phase process, was used, and the temperature of the substrate was maintained at a constant temperature between 0 and 900°C during the process. If necessary, the canister containing the metal precursor can be cooled or heated to a temperature between -20 and 150 °C. The metal film forming method of the present invention may include a post-treatment process to improve electrical characteristics, and the following examples may be used as the method.

According to one embodiment of the invention, reactant types include H ₂ , N ₂ , NH ₃ , hydrazine, O ₃ , O ₂ , H ₂ O, NOx, H ₂ S ₂ , (CH ₃ ) ₂ S ₂ , ((CH ₃ ) ₃ Si) ₂ Se, Te, FeTe ₂ , etc. may be used.

For example, the reduction method of one embodiment may be performed through thermal annealing or plasma treatment in a gas atmosphere of N ₂ , H ₂ , ammonia, hydrazine, borane, silane, or a mixture thereof.

According to one embodiment, the oxidation method may be performed through thermal annealing or plasma treatment in a gas atmosphere of O ₂ , O ₃ , H ₂ O or H ₂ O ₂ or a mixture thereof.

According to one embodiment, a post-treatment process may be performed after depositing the metal film. For example, the post-treatment process may be performed in a temperature range between 300 and 900 °C.

The metal film may have a thickness of 10 to 200 nm, or 50 to 150 nm. However, since the metal film thickness may vary depending on the purpose, it is not limited to the above metal film thickness numerical range.

After depositing the Mo thin film by vaporizing the Mo precursor, the film thickness may be in the range of 100 to 1,000 Å, and the specific resistance may be in the range of 180 to 2,000 μΩcm.

Additionally, the resistivity of the metal film after annealing at a temperature of 400° C. in a hydrogen or hydrogen plasma atmosphere may be in the range of 20 to 150 μΩcm. That is, after depositing a metal thin film, the resistivity can be further improved through annealing.

At this time, the resistivity of the metal film before and after annealing can be measured under the conditions of 300 K, 0.5 T, and 10 ^-3 mA using Hall effect measurement (Ecopia HMS-5000), respectively.

In the present invention, the physical properties of the metal film can be measured using devices well known in the field, and can be analyzed using, for example, an ellipsometer, XRR, SEM, TEM, XPS, etc.

As described above, in the present invention, by using a precursor compound for forming a metal film selected from the group consisting of compounds represented by the formulas 1 and 2, it is easy to remove reaction by-products and form a metal thin film with a low impurity content over a wide temperature range. can do.

Below, examples are presented to aid understanding of the invention. However, the following examples are only for illustrating the present invention and do not limit the invention to these only.

[Examples 1 to 9 and Comparative Example 1: Preparation of molybdenum (Mo) precursor]

Molybdenum-containing compounds of Chemical Formula 1 having the structures shown in Table 1 below were prepared and used as precursor compounds in Examples 1 to 9 and Comparative Example 1.

For example, weigh and add molybdenum hexacarbonyl (0.67 mol) and dimethoxyphenylphosphine (P(C ₆ H ₅ )(OCH ₃ ) ₂ ) (0.67 mol) to a 1L round flask with branches, 700 mL of toluene was added and the stirred suspension was refluxed for 10 hours using a reflux condenser. After completion of the reaction, the solvent and volatile side reactants were removed from the solution obtained by filtration under reduced pressure, and a viscous dark red-brown solution was obtained. This liquid was distilled under reduced pressure to obtain the compound (dimethoxy phenyl phosphine) molybdenum of Example 1 in Table 1, a viscous yellow liquid compound.

In addition, instead of the dimethoxyphenylphosphine, compounds having substituents R ₁ to R ₃ of Formula 1 in Table 1 were used, and the compounds of Examples 2 to 9 and Comparative Example 1 were prepared in the same manner as Example 1. was manufactured.

precursor compound Example 1 Example 2

Example 3 Example 4

Example 5 Example 6

Example 7 Example 8

Example 9 Comparative Example 1

[Experimental Example 1: Measurement of physical properties of precursor compound]

The physical properties of Examples 1 to 9 and Comparative Example 1 were measured using the following method, and the results are shown in Tables 2 and 3.

(1) T _decompose

The decomposition temperature of each Mo precursor compound was measured in an inert atmosphere using a differential scanning calorimetry device. The higher the decomposition temperature, the higher the thermal stability, and the higher the T1/2 temperature, the higher the thermal stability.

(2) T _1/2 wt%

Using a thermogravimetric analysis device (TGA), the temperature of each Mo precursor was volatilized in an inert atmosphere and the temperature of the compound was measured when the weight reached 50 wt%.

(3) TGA remaining amount (@400℃) (heat resistance evaluation)

Using a thermogravimetric analyzer (TGA), the mass loss rate was measured while raising the temperature to 400°C for each Mo precursor compound, and the remaining amount of TGA (@400°C) was calculated according to the weight loss curve. The TGA residual amount (@400°C) results of Examples 1 to 4 are shown graphically in Figure 1.

(4) Vapor pressure

The vapor pressure of the liquid was measured for each Mo compound using a vapor pressure measuring device.

Physical property table of precursor compounds Example 1 Example 2 Example 3 Example 4 Example 5 Molecular weight (g/mol) 406.14 386.15 401.16 528.38 486.31 T _decompose (℃) 251 265 266 270 280 T _1/2wt% (℃) 162 165 257 159 164 TGA remaining amount (@400℃) 4.8% 0.4% 3.6% 3.5 1.1% Phase (@25℃) Liquid Liquid Liquid Liquid Liquid boiling point 115℃@0.7torr 125℃@0.8torr 115℃@0.7torr 160℃@0.8torr 130℃@0.8torr Assay (purity) ≥99% ≥99% ≥99% ≥99% ≥99% transference number (%) 65 72 85 74 68 ^1H NMR
(C ₆ D ₆ , ppm) δ3.482 ([CH ₃ O]-PMo, d, 6H), 5.324 ([CH CH ₂ ]-PMo, m, 1H), 5.425 ([CHC H ₂ ]-PMo, m, 1H), 5.518 ( [CHC H ₂ ]-PMo, m, 1H) δ3.563 ([C H ₃ O]-PMo, d, 6H), 7.324 [C ₆ H ₅ ]-PMo, m, 5H) δ 1.02 ([CH ₃ C H ₂ N]-PMo, t, 4H), 2.96 ([ CH ₃ CH ₂ N]-PMo, m, 6H), 3.063 ([ CH ₃ O]-PMo, d, 6H) δ 3.804 ([(CH ₃ ) ₂ (CH2) ₂ C H O]-PMo, m, 3H), 1.532 ((CH ₃ ) ₂ (C H ₂ ) ₂ O]-PMo, m, 12H), 0.932 ( (C H ₃ ) ₂ (CH ₂ ) ₂ O]-PMo, t, 18H) δ 1.247 ([C(C H ₃ ) ₃ O]-PMo, s, 27H)

Physical property table of precursor compounds Example 6 Example 7 Example 8 Example 9 Comparative Example 1 Molecular weight (g/mol) 444.23 360.07 402.15 444.23 364.49 T _decompose (℃) 279 275 273 280 246 T _1/2wt% (℃) 170 146 168 175 165 TGA remaining amount (@400℃) 3.8% 7.4% 0.5% 0.7% 5.9 Phase (@25℃) Liquid Liquid Liquid Liquid Liquid boiling point 130℃@0.8torr 102℃@0.8torr 15℃@0.8torr 120℃@0.8torr 135℃@0.7torr Assay (purity) ≥99% ≥99% ≥99% ≥99% transference number (%) 62 88 71 60 59 ^1H NMR
(C ₆ D ₆ , ppm) δ 3.812 ([CH ₃ CH ₂ C H ₂ O]-PMo, m, 6H), 1.518 ([CH ₃ C H ₂ CH ₂ O]-PMo, m, 6H), 0.902 ([ CH ₃ CH ₂ CH ₂ O]-PMo, m, 9H) δ 3.123 ([C H ₃ O]-PMo, d, 9H) δ 3.856 ([CH ₃ C H ₂ O]-PMo, t, 6H), 1.268 ([ CH ₃ CH ₂ O]-PMo, m, 9H) δ 4.468 ([OC H (CH ₃ )2]-PMo, m, 3H), 1.095 ([OCH(C H ₃ ) ₂ ]-PMo, d, 18H) δ 3.583 ([C H ₃ O]-PMo, d, 3H)

[Experimental Example 2-3: Formation of metal film]

<Experimental Example 2: Method of forming molybdenum film>

In this experimental example, showerhead-type atomic layer deposition was introduced to form metal films using the precursor compounds of Examples 1 to 9 and Comparative Example 1 (Mo precursor in a liquid state at room temperature) and H ₂ as a reaction gas. did. The metal precursor was used in a canister, and the canister was used without additional heating.

The ALD process was performed in one cycle [Mo precursor injection - purge - reactants injection - purge], and high purity Ar was used as the purge gas (20 seconds). The cycle was repeated 1 to 500 times until a certain thickness was reached. The substrate used was Si or SiO ₂ wafer. The temperature of the substrate was carried out at 250°C.

Afterwards, the physical properties of each metal film were measured using the following method, and the results are shown in Table 2.

(1) Thickness (nm)

After metal (Mo) deposition, the thickness and density of the thin film were measured using an ellipsometer or X-ray reflectometry (XRR).

(2) Growth per cycle (GPC) (Å/cycle)

After metal deposition for each precursor, the film thickness was measured using an ellipsometer, and the deposition rate per cycle (GPC) (Å/cycle) was calculated.

(3) Sheet resistance (Ω/□)

Sheet resistance was measured using a four point probe using a sheet resistance meter.

(4) Resistivity (μΩcm)

The resistivity of the metal film was measured under the conditions of 300 K, 0.5 T, and 10 ^-3 mA using Hall effect measurement (Ecopia HMS-5000).

(5) XPS surface composition measurement

The XPS surface components were measured for each metal film (Mo) using XPS (X-ray photoelectron spectroscopy), and the results are shown in Tables 4 and 5.

Specifically, the contents of Mo, N, O, P, C, As, Si, Cl, etc. in the metal film were confirmed through XPS (X-ray photoelectron spectroscopy, ThermoFisher Scientific NEXSA) depth profile analysis, and the binding energy of each element was determined. The spectrum was also checked and the content was analyzed (based on 100% by weight of total content).

Physical properties table of metal film (Mo) Example 1 Example 2 Example 3 Example 4 Example 5 Thickness (nm) 70.3 58.4 59.7 65.2 59.9 GPC(Å/cycle) 3.52 2.92 2.99 3.26 3.00 Sheet resistance (Ω/□) 72.5 74.5 60.8 58.1 45.2 Specific resistance (μΩcm) 509.68 435.08 392.98 378.81 270.75 XPS surface composition and composition (% by weight) Mo: 50.25
C: 29.14
O:20.61
P:0
Cl:0 Mo: 51.44
C: 17.87
O: 30.69
P: 0
Cl: 0 Mo:53.29
C: 20.53
O: 26.18
P: 0
Cl:0 Mo:50.42
C: 23.24
O: 26.34
P:0
Cl:0 Mo:51.25
C:16.52
O:32.23
P: 0
Cl:0

Physical properties table of metal film (Mo) Example 6 Example 7 Example 8 Example 9 Comparative Example 1 Thickness (nm) 64.2 61.4 59.8 60.6 60.8 GPC(Å/cycle) 3.21 3.07 2.99 3.03 3.04 sheet resistance
(Ω/□) 40.8 30.5 30.8 28.4 85.5 Specific resistance (μΩcm) 261.93 187.24 184.18 172.10 519.84 XPS surface composition and composition (% by weight) Mo:53.51C:20.48
O:26.01
P: 0
Cl:0 Mo: 53.57
C: 21.97
O: 24.44
P: 0
Cl:0 Mo: 50.24
C: 26.24
O:27.24
P: 0
Cl:0 Mo: 56.42
C: 17.25
O: 26.33
P: 0
Cl:0 Mo: 45.57
C: 23.58
O: 22.82
P: 0
Cl:8.02

Looking at the results in Tables 4 and 5, the Mo metal film containing the metal derived from the precursor compounds of Examples 1 to 9 is prevented from generating reaction by-products by the precursor compounds of the Examples, thereby performing a stable deposition process. , a metal film was formed with lower sheet resistance and specific resistance than Comparative Example 1 containing halogen.

Additionally, when comparing the examples, the effect improved further in the order of Examples 1 to 9. When comparing Example 1 with Examples 2 to 9, the effect was relatively better when R ₁ to R ₃ did not have an aryl group than when any one of R ₁ to R ₃ had an aryl group. That is, due to the bulky structural characteristics of the aryl group, if any one or more of R ₁ to R ₃ includes an aryl group, the effect may be relatively inferior to other substituents of the examples excluding the aryl group. Therefore, Examples 2 to 9 did not contain an aryl group in the structure, and were relatively more effective than Example 1, which included an aryl group with a bulky molecular structure.

In addition, when at least one of R ₁ to R ₃ is a substituted or unsubstituted saturated or unsaturated alkoxy group having 1 to 10 carbon atoms, when comparing Examples 7 and 8 with different carbon atoms, R ₁ to R ₃ Example 8, which has an unsubstituted saturated alkoxy group having 2 carbon atoms, had relatively lower sheet resistance and specific resistance than Example 7, wherein all of R ₁ to R ₃ had methoxy groups with 1 carbon atom, showing superior effectiveness.

When comparing Examples 8 and 9 with different carbon atoms, Example ₉ , wherein R ₁ to R ₃ has an unsubstituted saturated branched alkoxy group of 3 carbon atoms, has a saturated branched alkoxy group of ₃ carbon atoms. The sheet resistance and specific resistance were relatively lower than those of Example 8 having an alkoxy group, so the effect was excellent. That is, it can be confirmed that when R ₁ to R ₃ have an unsubstituted saturated alkoxy group having 3 carbon atoms and a branched structure, it has a better effect than a saturated alkoxy group having 2 carbon atoms.

In addition, when comparing Examples 4 and 5, which are branched _and have different carbon atoms, Example 5, in which R ₁ to R ₃ is unsubstituted and has a saturated branched alkoxy group of ₄ carbon atoms, is Compared to Example 4, which has an unsubstituted branched alkoxy group with 5 carbon atoms, the sheet resistance and specific resistance were relatively lower due to the smaller number of carbon atoms even though it included a branched structure in the structure, showing a good effect. In addition, when comparing Examples 5 and 9, which have branching _and different carbon atoms, Example 9, in which R ₁ to R ₃ has an unsubstituted saturated branched alkoxy group of ₃ carbon atoms, has Compared to Example 5, which has an unsubstituted branched branched alkoxy group with 4 carbon atoms, the sheet resistance and specific resistance were relatively lower due to the smaller number of carbon atoms even though the branched structure was included in the structure, showing a good effect.

In addition, when comparing Examples 8 and 9 with different carbon atoms, Example 9, which has a branched alkoxy group of 3 carbon atoms in which R ₁ to R ₃ is unsubstituted, has a branched alkoxy group of 2 carbon atoms in which R ₁ to R ₃ are unsubstituted. Compared to Example 8, which has an alkoxy group, the number of carbon atoms was lower and the sheet resistance and specific resistance were relatively lower, showing good effects.

When at least one of R ₁ to R ₃ is a substituted or unsubstituted saturated or unsaturated alkoxy group having 3 to 6 carbon atoms, when comparing Examples 6 and 9 where R ₁ to R ₃ have the same carbon number, Example 9, in which R _{1 to} R ₃ have unsubstituted saturated branched alkoxy groups having ₃ carbon atoms, has relatively higher sheet resistance and The specific resistance was lower and the effect was excellent.

In addition, when comparing Examples 1, 2, and 7, Example 7 in which R ₁ to R ₃ has the same structure is different from Example 1 and 2 in which any one of R ₁ to R ₃ has a different structure. The effect was excellent because the sheet resistance and specific resistance were relatively lower.

On the other hand, Comparative Example 1 used a precursor compound containing a linear alkyl structure containing halogen, and even though the impurity content was low, chloride was excessively contained at more than 8% when depositing the metal film. Accordingly, Comparative Example 1 showed relatively high sheet resistance and specific resistance of the metal film compared to the Examples. Therefore, Comparative Example 1 may cause problems such as deterioration in the performance of the metal film and deterioration of the electrical properties due to high sheet resistance.

<Experimental Example 3: Method of forming molybdenum nitride (MoN) film>

In this experimental example, showerhead-type atomic layer deposition was introduced, using the precursor compounds of Examples 1 to 9 and Comparative Example 1 (Mo precursor in a liquid state at room temperature) and NH ₃ plasma as a reaction gas, respectively, to form metal A membrane was formed. The metal precursor compound was used in a canister, and the canister was used without additional heating.

The ALD process was carried out in one cycle [Mo precursor injection - purge - reactants injection - purge], and high purity Ar was used as purge gas. The cycle was repeated 1 to 500 times until a certain thickness was reached. The substrate used was Si or SiO ₂ wafer. The temperature of the substrate was carried out at 225 °C. Additionally, some selected samples are analyzed by SEM, TEM, and XPS.

In the same manner as in Experimental Example 1, the physical properties of each metal film were measured and the results are shown in Tables 6 and 7.

Physical properties table of metal film (MoN) Example 1 Example 2 Example 3 Example 4 Example 5 Thickness (nm) 85 69 68 70 66 GPC(Å/cycle) 8.5 6.9 6.8 7.0 6.6 Sheet resistance (Ω/□) 840 993 1003 970 1024 Specific resistance (μΩcm) 7.14k 6.85k 6.82k 6.79k 6.76k XPS surface composition and composition (% by weight) Mo:24.25N:25.36
C: 17.14
O: 33.25
P: 0
Cl:0 Mo: 31.36
N: 34.28
C: 12.32
O: 22.04
P: 0
Cl: 0 Mo:29.48
N:30.14
C:15.24
O:25.14
P: 0
Cl: 0 Mo:26.79
N: 36.52
C: 16.21
O: 20.48
P: 0
Cl:0 Mo:33.24
N:36.14
C: 14.52
O:16.10
P:0
Cl:0

Physical properties table of metal film (MoN) Example 6 Example 7 Example 8 Example 9 Comparative Example 1 Thickness (nm) 68 69 67 72 74 GPC(Å/cycle) 6.8 6.9 6.7 7.2 7.4 Sheet resistance (Ω/□) 988 971 984 908 988 Specific resistance (μΩcm) 6.72k 6.70k 6.59k 6.54k 7.31k XPS surface composition and composition (% by weight) Mo:29.84N:33.25
C:17.52
O:19.39
P:0
Cl:0 Mo: 30.15
N: 32.47
C: 13.27
O: 24.11
P: 0
Cl:0 Mo: 30.47
N:36.11
C: 16.48
O:16.94
P:0
Cl:0 Mo: 32.42
N: 35.07
C: 11.27
O: 21.24
P: 0
Cl:0 Mo: 28.32
N: 31.21
C: 14.16
O: 22.79
P: 0
Cl:3.52

As shown in Tables 6 and 7, even in alloys containing Mo (MoN), metal films derived from the precursor compounds of Examples 1 to 9 are prevented from generating reaction by-products by the precursor compounds of the above Examples, resulting in a stable deposition process. As this was performed, a metal film with lower sheet resistance and specific resistance than Comparative Example 1 was formed.

In addition, when comparing the examples, the effect improved further in the order of Examples 1 to 9, similar to the Mo thin film results.

Claims (14)

A precursor compound for forming a metal film comprising at least one member selected from the group consisting of compounds represented by the following formulas 1 and 2: [Formula 1]

[Formula 2]

In Formulas 1 and 2, M is each independently a transition metal selected from the group consisting of Cr, Mo, W, V, Nb and Ta, R ₁ is each independently hydrogen, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted linear or branched, saturated or unsaturated alkoxy group having 1 to 10 carbon atoms, or an aryl group having 5 to 20 carbon atoms. , a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms, a substituted or unsubstituted aralkoxy group having 5 to 30 carbon atoms, a substituted or unsubstituted amino group, or isomers thereof, R ₂ and R ₃ are each independently hydrogen, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted linear or branched, saturated or unsaturated alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkyl group. A linear or branched, saturated or unsaturated alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 5 to 20 carbon atoms, a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms, or a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms. to 30 aralkoxy groups, substituted or unsubstituted amino groups, or isomers thereof. The compound according to claim 1, which is used as a precursor for a semiconductor. According to paragraph 1, Wherein R ₁ is each independently a substituted or unsubstituted linear or branched, saturated or unsaturated alkoxy group having 1 to 10 carbon atoms, or a substituted or unsubstituted amino group, R ₂ and R ₃ are each independently a substituted or unsubstituted linear or branched, saturated or unsaturated alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted linear or branched, saturated or unsaturated alkyl group having 1 to 10 carbon atoms. A compound that is an alkoxy group, or a substituted or unsubstituted amino group. According to paragraph 1, A compound wherein at least one of R ₁ to R ₃ is a substituted or unsubstituted saturated or unsaturated alkoxy group having 1 to 10 carbon atoms. According to paragraph 1, A compound wherein at least one of R ₁ to R ₃ is a substituted or unsubstituted saturated or unsaturated alkoxy group having 2 to 10 carbon atoms. According to paragraph 1, A compound wherein at least one of R ₁ to R ₃ is a substituted or unsubstituted saturated or unsaturated alkoxy group having 3 to 4 carbon atoms. According to paragraph 1, A compound wherein at least one of R ₁ to R ₃ is a substituted or unsubstituted saturated or unsaturated alkoxy group having 3 carbon atoms. According to paragraph 1, A compound in which at least one of R ₁ to R ₃ is a substituted or unsubstituted alkoxy group having a saturated or unsaturated branched structure having 3 to 6 carbon atoms. According to paragraph 1, A compound wherein R ₁ to R ₃ have the same structure. The compound according to claim 1, wherein the precursor compound is any one selected from compounds having the following structures.

According to paragraph 1, The compound has a TGA residual amount (@400°C) of 10% or less. According to paragraph 1, The above compound is a compound with a purity of 99% or more. A metal film derived from one or more precursor compounds for forming a metal film selected from the group consisting of compounds represented by the following formulas 1 and 2: [Formula 1]

[Formula 2]

In Formulas 1 and 2, M is each independently a transition metal selected from the group consisting of Cr, Mo, W, V, Nb and Ta, R ₁ is each independently hydrogen, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted linear or branched, saturated or unsaturated alkoxy group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group having 5 carbon atoms. an aryl group having 5 to 20 carbon atoms, a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms, a substituted or unsubstituted aralkoxy group having 5 to 30 carbon atoms, a substituted or unsubstituted amino group, or isomers thereof, R ₂ and R ₃ are each independently hydrogen, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted linear or branched, saturated or unsaturated alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkyl group. A linear or branched, saturated or unsaturated alkoxy group having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group having 5 to 20 carbon atoms, a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms, or a substituted or unsubstituted aralkyl group having 5 to 30 carbon atoms. to 30 aralkoxy groups, substituted or unsubstituted amino groups, or isomers thereof. According to clause 13, The metal film is a Mo thin film, a MoN thin film, or a MoO ₂ thin film.

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