KR20210064623A - Precursor for film deposition, deposition method of film and semiconductor device of the same - Google Patents

Abstract

The present invention relates to a precursor for forming a metal film. The precursor comprises an organometallic compound represented by the following formula 1. [Formula 1] In Formula 1, M is Ti, Zr, or Hf, X is a hydrogen atom, a C_1-C_5 alkyl group, NR_4R_5, or OR_6, R1 to R6 can be the same as or different from each other, and each independently represents a hydrogen atom or a C_1-C_5 linear, branched, or cyclic alkyl group, and n is a natural number of 2 or 3. Therefore, the present invention can provide the precursor of which the stability is increased using the organometallic compound having a cross-linked structure.

Description

A precursor for forming a metal thin film, a method for forming a metal thin film using the same, and a semiconductor device including the metal thin film. {PRECURSOR FOR FILM DEPOSITION, DEPOSITION METHOD OF FILM AND SEMICONDUCTOR DEVICE OF THE SAME}

The present invention relates to a precursor for forming a metal thin film, a method for forming a metal thin film using the same, and a semiconductor device including the metal thin film, and more particularly, to a precursor used in an atomic layer deposition (ALD) or chemical vapor deposition (CVD) process. A precursor capable of forming a thin film such as a metal-containing thin film, a transition metal silicate, or a silicon-doped metal-containing thin film containing Group 4 metal and silicon (Si), a method for forming a metal thin film using the same, and a semiconductor device including the metal thin film it's about

Various types of organometallic compounds have been developed and used as precursors for atomic layer deposition (ALD) or chemical vapor deposition (CVD) processes. Such organometallic compounds are required to have characteristics such as vaporization characteristics, a difference between vaporization temperature and decomposition temperature, toxicity, chemical stability, thermal stability, compound synthesis, ease of thermal decomposition, and the like.

One of these organometallic compounds is an organometallic compound in the form of a complex compound containing a cyclopentadienyl group. In particular, an organometallic compound precursor in which a cross-linked structure is formed between a cyclopentadienyl group and a central metal atom is a thin film. It is known to be effective in forming

For example, in Korean Patent Publication No. 10-1263454, a cross-linked structure of alkylamine is formed between a cyclopentadienyl group such as _{Zr(CpCH 2} CH ₂ NMe)(NMe ₂ ) _{2 and a zirconium atom, thereby providing thermal stability and step coverage} It has excellent properties and exhibits excellent properties as a precursor that does not decompose even when stored for a long time at high temperatures.

In addition, Korean Patent No. 10-1959519 discloses a technology for forming a transition metal silicate thin film using an organometallic compound containing a metal atom and a silicon atom, and by adopting a cross-linked structure with high thermal stability, one precursor can form a transition metal silicate thin film.

In Korean Patent Laid-Open Publication No. 10-2019-0108281, the applicant uses an organometallic compound in which a cross-linked structure is formed between a central metal and a cyclopentadienyl group to provide a precursor that has excellent thermal stability and can solve problems occurring during the miniaturization process. have been developed

Based on this basic structure, it is expected to provide effective precursors for ALD or CVD by developing new precursors suitable for high-temperature deposition.

Republic of Korea Patent Publication No. 10-1263454 Republic of Korea Patent Publication No. 10-1959519 Korean Patent Publication No. 10-2019-0108281

The present invention has been devised in view of the prior art as described above, and an object of the present invention is to provide a precursor for forming _{a transition metal silicate (MSiO x ) thin film suitable for high-temperature deposition due to excellent thermal stability.}

Another object of the present invention is to provide a precursor for forming a thin film having increased stability through an organometallic compound having a cross-linked structure.

Another object of the present invention is to provide a precursor capable of forming a transition metal silicate thin film by applying one organometallic compound containing a transition metal and a silicon atom as a precursor.

Another object of the present invention is to provide a method of forming a metal thin film using the precursor and a method of manufacturing a semiconductor device including the metal thin film.

The precursor for forming a metal thin film of the present invention for achieving the above object is characterized in that it comprises an organometallic compound represented by the following formula (1).

[Formula 1]

In Formula 1, M is Ti, Zr, or Hf, X is a hydrogen atom, an alkyl group, NR ₄ R ₅ or OR ₆ , R ₁ to R ₆ may be the same as or different from each other, and each independently a hydrogen atom Or C ₁ -C ₅ A straight-chain, branched or cyclic alkyl group, n is a natural number of 2 or 3.

In addition, the precursor may additionally include a solvent, and the solvent may be _{any one or more of C 1} -C ₁₆ saturated or unsaturated hydrocarbons, ketones, ethers, glymes, esters, tetrahydrofuran, and tertiary amines. have.

In addition, the solvent may be included in an amount of 1 to 99% by weight based on the total weight of the precursor for forming the metal thin film.

The method for forming a metal thin film according to the present invention includes depositing a metal thin film on a substrate using the precursor for forming a metal thin film.

In this case, the metal thin film may be deposited by atomic layer deposition or may be deposited by chemical vapor deposition.

In addition, the method may include vaporizing the precursor for forming the metal thin film and transferring the precursor into the chamber.

In addition, the depositing may include positioning a substrate in a chamber, supplying the precursor composition for forming the metal thin film into the chamber, supplying a reactive gas or plasma of the reactive gas into the chamber, and heat in the chamber. It may include the step of treating by any one or more means of treatment, plasma treatment, and light irradiation, and may be performed at 250 to 400°C.

The semiconductor device according to the present invention is characterized in that it includes a metal thin film manufactured by the method for forming the metal thin film.

Since the precursor according to the present invention has excellent thermal stability and is suitable for high-temperature deposition, it is suitable for forming a _{metal thin film, in particular, a transition metal silicate (MSiO x ) thin film.}

In addition, thermal stability is increased through an organometallic compound having a crosslinked structure, and a transition metal silicate thin film can be formed in a single process by simultaneously containing a metal atom and a silicon atom in one compound.

In addition, it is possible to provide a method of forming a metal thin film by using the precursor and a method of manufacturing various semiconductor devices including the metal thin film.

1 is a conceptual diagram illustrating a thin film formation process using a precursor of the present invention.

Hereinafter, the present invention will be described in more detail. The terms or words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and the inventor may properly define the concept of the term in order to best describe his invention. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that there is.

The precursor for forming a metal thin film according to the present invention is characterized in that it comprises an organometallic compound represented by the following formula (1).

[Formula 1]

In Formula 1, M is Ti, Zr, or Hf, X is a hydrogen atom, a C ₁ -C ₅ alkyl group, NR ₄ R ₅ or OR ₆ , R ₁ to R ₆ may be the same as or different from each other, , each independently a hydrogen atom or a C ₁ -C ₅ linear, branched or cyclic alkyl group, and n is a natural number of 2 or 3.

The organometallic compound as described above may be prepared through a conventional ligand synthesis method. That is, as shown in Schemes 1 to 3, a first step of reacting cyclopentane with an alkylamino compound, a second step of reacting the reaction product with an alkylsilicon compound, and a third step of reacting the reaction product with a zirconium compound can do.

[Scheme 1]

[Scheme 2]

[Scheme 3]

The organometallic compound represented by Formula 1 may specifically include an organometallic compound selected from the following structures, but is not limited thereto.

The precursor of the present invention may further include a solvent. As the solvent, any one of C ₁ -C ₁₆ saturated or unsaturated hydrocarbon, ketone, ether, glyme, ester, tetrahydrofuran, tertiary amine, or a mixture thereof may be used. Examples of the C ₁ -C ₁₆ saturated or unsaturated hydrocarbon include toluene and heptane, and the tertiary amine includes dimethylethylamine.

In addition, when the solvent is included, it is preferably included in an amount of 1 to 99% by weight based on the total weight of the precursor for forming a metal film.

A precursor containing or not containing a solvent can be vaporized, and the deposition process can be performed by supplying it into the chamber, and it is preferable to appropriately select and use a soluble solvent according to the properties of the organometallic compound. That is, depending on the type of the organometallic compound, when it exists in the liquid phase at room temperature, the deposition process may be performed without a separate solvent.

The method for forming a metal thin film of the present invention is characterized in that it includes depositing a metal thin film on a substrate using the precursor for forming a metal thin film.

In this case, the precursor for forming the metal thin film may additionally include a solvent as described above, and the solvent may be included in an amount of 1 to 99 wt% based on the total weight of the precursor for forming the metal thin film.

The method for manufacturing a metal thin film using a precursor containing an organometallic compound represented by Formula 1 is according to the conventional method for manufacturing a metal thin film by vapor deposition, except that the organometallic compound represented by Formula 1 is used as a metal precursor. It may be carried out, and specifically, it may be carried out by a method such as chemical vapor deposition (CVD) or atomic layer deposition (ALD).

That is, the step of supplying the organometallic compound represented by Formula 1 onto the substrate for forming a metal thin film existing in the reactor, and supplying a reactive gas into the reactor, one selected from the group consisting of heat treatment, plasma treatment and light irradiation It may be prepared by a manufacturing method comprising the step of subjecting the species to a treatment process.

Referring to FIG. 1, the thin film formation process is described. First, the precursor of the present invention is introduced on a substrate on which a reaction site is formed (FIG. 1(a)). The reactive group (X) bonded to the central metal atom of the organometallic compound represented by Formula 1 constituting the precursor and the reactive group on the surface of the substrate are bonded, and in this case, the reactive group on the surface of the adjacent substrate is cross-linked to the central metal atom. Electron transfer occurs to the silicon atom of the silyl group, and at the same time, electron transfer occurs from the silicon atom to another surface reactive group (FIG. 1(b)). Then, when a reactive gas is supplied, metal atoms and silicon atoms are simultaneously deposited on the surface of the substrate, thereby forming a thin film of _{transition metal silicate (MSiO x ).}

The substrate for forming the metal thin film may be used without any particular limitation as long as it is used in semiconductor manufacturing, which needs to be coated with a metal thin film due to a technical action. Specifically, a silicon substrate (Si), a silica substrate (SiO ₂ ), a silicon nitride substrate (SiN), a silicon oxynitride substrate (SiON), a titanium nitride substrate (TiN), a tantalum nitride substrate (TaN), a tungsten substrate (W) or a noble metal substrate such as a platinum substrate (Pt), a palladium substrate (Pd), a rhodium substrate (Rh), or a gold substrate (Au) may be used.

The organometallic compound represented by Formula 1 may be transferred through a volatilized gas, or a liquid transfer method may be used in which a direct liquid injection method or a liquid transfer method in which the organometallic compound is dissolved in an organic solvent is transferred. In the method of transferring the precursor to the volatilized gas, the container containing the precursor is placed in a thermostat, and then the precursor is evaporated by bubbling with an inert gas such as helium, neon, argon, krypton, xenon, or nitrogen to form a metal thin film. It may be carried out by transferring it onto the substrate, or by using a liquid delivery system (LDS) to change a liquid precursor into a vapor phase through a vaporizer and then transfer it onto a substrate for forming a metal thin film.

In the case of a liquid transport method in which a precursor is dissolved in an organic solvent and transported, as described above, it can be used in the form of a composition consisting of an organometallic compound represented by Chemical Formula 1 and a solvent, and among the organometallic compounds represented by Chemical Formula 1, high When it is difficult to sufficiently vaporize in a liquid transfer type vaporizer due to viscosity, the deposition process can be effectively performed by using the composition in the form of a solvent.

Such a solvent must have a property of dissolving a solid substance or a solvent capable of dissolving and dispersing a liquid substance. In addition, in consideration of the boiling point, density, and vapor pressure conditions of the solvent, the effect of reducing the viscosity and improving the volatility of the composition for forming a thin film is improved, and through this, the uniformity and step coverage of the deposited thin film are improved. It is desirable to select the solvent to allow for improved thin film formation.

In addition, when the organometallic compound represented by Formula 1 is supplied into the chamber, silicon (Si), titanium (Ti), A metal precursor comprising at least one metal (M″) selected from germanium (Ge), strontium (Sr), niobium (Nb), barium (Ba), hafnium (Hf), tantalum (Ta) and lanthanide atoms is selected The second metal precursor may be an alkylamide compound or an alkoxy compound containing the metal. For example, when the metal is Si, the second metal precursor is SiH(N(CH ₃ ) ₂ ) ₃ , Si(N(C ₂ H ₅ ) ₂ ) ₄ , Si(N(C ₂ H ₅ )(CH ₃ )) ₄ , Si(N(CH ₃ ) ₂ ) ₄ , Si(OC ₄ H ₉ ) ₄ , Si(OC ₂ H ₅ ) ₄ , Si(OCH ₃ ) ₄ , Si(OC(CH ₃ ) ₃ ) _{4 ,} and the like may be used.

The supply of the second metal precursor may be performed in the same manner as the method of supplying the metal precursor of Chemical Formula 1, and the second metal precursor may be supplied on the substrate for forming a thin film together with the metal precursor of Chemical Formula 1, or a metal After the supply of the precursor is completed, it may be sequentially supplied.

The metal precursor of Chemical Formula 1 and optionally the second metal precursor as described above are preferably maintained at a temperature of 100 to 200° C. before being supplied into the reaction chamber in order to contact the substrate for forming a metal film, and more preferably 130 It is preferable to maintain the temperature of to 180 ℃.

In addition, after the supplying of the metal precursor and prior to the supply of the reactive gas, the metal precursor of Formula 1 and optionally the second metal precursor are helped to move onto the substrate, or to have an appropriate pressure for deposition in the reactor, and also to the chamber. A process of purging an inert gas such as _{argon (Ar), nitrogen (N 2} ), or helium (He) in the reactor may be performed in order to discharge impurities present in the reactor to the outside. At this time, it is preferable that the inert gas is purged so that the pressure in the reactor is 1 to 5 Torr.

After the supply of the metal precursors is completed, a reactive gas is supplied into the reactor, and one type of treatment process selected from the group consisting of heat treatment, plasma treatment, and light irradiation is performed in the presence of the reactive gas.

As the reactive gas, water vapor (H ₂ O), oxygen (O ₂ ), ozone (O ₃ ), hydrogen peroxide (H ₂ O ₂ ), hydrogen (H ₂ ), ammonia (NH ₃ ), nitrogen monoxide (NO), nitrous oxide Any one of nitrogen (N ₂ O), nitrogen dioxide (NO ₂ ), hydrazine (N ₂ H ₄ ), and silane (SiH ₄ ) or a mixture thereof may be used. When carried out in the presence of an oxidizing gas such as water vapor, oxygen, ozone, etc., a metal oxide thin film may be formed, and when carried out in the presence of a reducing gas such as hydrogen, ammonia, hydrazine, silane, a thin film of a single metal or a metal nitride is formed. can

In addition, the heat treatment, plasma treatment, or the treatment process of light irradiation is to provide thermal energy for deposition of a metal precursor, and may be performed according to a conventional method. Preferably, at a sufficient growth rate, in order to produce a metal thin film having a desired physical state and composition, it is preferable to carry out the treatment process so that the temperature of the substrate in the reactor is 100 to 1,000°C, preferably 250 to 400°C. desirable.

In addition, during the treatment process, as described above, in order to help the movement of the reactive gas onto the substrate, to have an appropriate pressure for deposition in the reactor, and to discharge impurities or by-products present in the reactor to the outside, A process of purging an inert gas such as argon (Ar), nitrogen (N ₂ ), or helium (He) may be performed.

As described above, the input of the metal precursor, the input of the reactive gas, and the input of the inert gas are treated as one cycle. A metal-containing thin film can be formed by repeating one cycle or more.

Specifically, when an oxidizing gas is used as the reactive gas, the metal-containing thin film prepared may include a metal oxide of Formula 2 below:

[Formula 2]

(M _1-a M" _a )O _b

In Formula 2, a is 0 ≤ a < 1, b is 0 < b ≤ 2, M is selected from the group consisting of Zr, Hf and Ti, and M" is derived from a second metal precursor, silicon (Si), titanium (Ti), germanium (Ge), strontium (Sr), niobium (Nb), barium (Ba), hafnium (Hf), tantalum (Ta) and lanthanide atoms.

In this method of manufacturing a metal thin film, by using a metal precursor having excellent thermal stability, the deposition process can be performed at a higher temperature than in the prior art during the deposition process, and high purity without particle contamination or contamination of impurities such as carbon due to thermal decomposition of the precursor. A thin film of metal, metal oxide or metal nitride can be formed. Accordingly, the metal-containing thin film formed according to the manufacturing method of the present invention is useful as a high-k material film in a semiconductor device, particularly DRAM, CMOS, and the like in a semiconductor memory device.

As another embodiment, a metal thin film formed by the method of forming the metal thin film, and a semiconductor device including the thin film are provided. For example, the semiconductor device may be a semiconductor device including a metal insulator metal (MIM) for random access memory (RAM).

In addition, since the semiconductor device is the same as that of a conventional semiconductor device, except that the metal-containing thin film according to the present invention is included in a material film requiring high dielectric properties such as DRAM in the device, the configuration of the semiconductor device in the present specification A detailed description of the will be omitted.

Although the present invention has been described with reference to preferred embodiments as described above, it is not limited to the above embodiments and various modifications are made by those of ordinary skill in the art to which the invention pertains without departing from the spirit of the present invention. and can be changed Such modifications and variations are intended to fall within the scope of the present invention and the appended claims.

Claims (10)

A precursor for forming a metal thin film comprising an organometallic compound represented by the following formula (1).

[Formula 1]

In Formula 1,
M is Ti, Zr, or Hf;
X is a hydrogen atom, a C ₁ -C ₅ alkyl group, NR ₄ R ₅ or OR ₆ ,
R ₁ to R ₆ may be the same as or different from each other, and each independently represents a hydrogen atom or a C ₁ -C ₅ linear, branched or cyclic alkyl group,
n is a natural number of 2 or 3.
The method according to claim 1,
A precursor for forming a metal thin film, characterized in that it further comprises a solvent.
3. The method according to claim 2,
The solvent is C ₁ -C ₁₆ A precursor for forming a metal thin film, characterized in that any one or more of saturated or unsaturated hydrocarbons, ketones, ethers, glyme, esters, tetrahydrofuran, and tertiary amines.
3. The method according to claim 2,
The solvent is a precursor for forming a metal thin film, characterized in that it is included in an amount of 1 to 99% by weight based on the total weight of the precursor for forming a metal thin film.
A method for forming a metal thin film, comprising depositing a metal thin film on a substrate using the precursor for forming a metal thin film according to claim 1 or 2.
6. The method of claim 5,
The metal thin film is a metal thin film forming method, characterized in that deposited by atomic layer deposition or chemical vapor deposition.
6. The method of claim 5,
and vaporizing the precursor for forming the metal thin film and transferring the precursor into the chamber.
6. The method of claim 5,
The depositing step is
positioning the substrate in the chamber;
supplying the precursor composition for forming the metal thin film into the chamber;
supplying a reactive gas or plasma of the reactive gas into the chamber;
processing in the chamber by any one or more means of heat treatment, plasma treatment, and light irradiation;
A method of forming a metal film comprising a.
9. The method of claim 8,
The depositing step is a metal film forming method, characterized in that performed at 250 to 400 ℃.
A semiconductor device comprising a metal thin film manufactured by the metal thin film forming method of claim 5 .

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