TW201542574A - Precursor compounds and deposition methods of thin film and amorphous silicon film using the same - Google Patents

Abstract

According to an embodiment of the present invention, a precursor compound is represented by (Formula 1), and R1 is one of a halide group, hydrogen, an alkyl group, a cyclic alkyl group, a phenyl group and a silyl group, the number of carbon of the alkyl group is one of 1 to 4, and the number of the cyclic alkyl group is one of 4 to 7.

Description

Precursor compound and method for depositing thin film and amorphous germanium layer therewith

The present invention relates to a precursor compound and a method of depositing the same and an amorphous tantalum film (layer) using the same. More specifically, it relates to an organic germanium precursor compound for efficiently depositing a thin film on a substrate, and a method for efficiently depositing the thin film and the amorphous germanium film (layer).

Due to the increased integration degree of semiconductor devices, tantalum films with diverse properties are required. Based on the increase in the degree of integration of semiconductor devices, the aspect ratio is increased, and the performance obtained by depositing a germanium film with a conventional disilane is lagging behind the required performance. Thin films deposited via dioxane may be difficult to achieve good step coverage and may form irregular voids in highly integrated semiconductor devices.

Due to the above drawbacks, efforts have been made to obtain a tantalum film in a novel manner, rather than a conventional dioxane tantalum film deposition method. Korean Patent Publication No. 2011-0119581 (published on Nov. 2, 2011) discloses a method of forming a thin layer on a lower substrate to deposit a thin film using diisopropylamino silane (DIPAS). And a decane-based gas is supplied. However, the amino decane precursor is limited to butylaminosilane (BAS), bistertiarybutylaminosilane (BTBAS), dimethylaminosilane (DMAS), didimethyl Bisdimethylaminosilane; BDMAS), tridimethylaminosilane (TDMAS), diethylaminosilane (DEAS), bisdiethylaminosilane (BDEAS), dipropylamino decane (dipropylamino silane) Dipropylaminosilane; DPAS), and diisopropylaminosilane (DIPAS), and the yield of highly integrated substrates may be degraded by the performance of the substrate heating process.

[Previous Technical Document]

(Patent Document 1) Korean Patent Publication No. 2011-0119581 (published on November 2, 2011)

One aspect of the invention provides a precursor for the effective formation of a ruthenium film on the surface of a substrate.

Another aspect of the invention will be apparent from the following detailed description.

According to an aspect of the invention, there is provided a precursor compound which is represented by <Formula 1>. R ¹ is ^one of halogen, hydrogen, alkyl, cycloalkyl, phenyl, and fluorenyl, the alkyl group has one carbon to one, and the cycloalkyl has 4 to 7 carbon atoms. One.

R ¹ may be a halogen of Cl, and the precursor compound may be represented by <Formula 2>.

<Formula 2>

R ¹ may be hydrogen, and the precursor compound may be represented by <Form 3>.

R ¹ may be a methyl group, and the precursor compound may be represented by <Formula 4>.

R ¹ may be a phenyl group, and the precursor compound may be represented by <Formula 5>.

R ¹ may be a fluorenyl group, and the precursor compound may be represented by <Form 6>.

<Formula 6>

R ² may be hydrogen, R ³ and R ⁴ may be a methyl group, and the precursor compound may be represented by <Formula 7>.

R ² to R ⁴ may be a methyl group, and the precursor compound may be represented by <Formula 8>.

According to another aspect of the present invention, there is provided a thin film deposition method comprising using a precursor film deposition film on a substrate using <Formula 1>. R ¹ is ^one of halogen, hydrogen, alkyl, cycloalkyl, phenyl, and fluorenyl, the alkyl group has one carbon to one, and the cycloalkyl has 4 to 7 carbon atoms. One.

<Formula 1>

In accordance with another aspect of the invention, a method of depositing an amorphous germanium layer is provided for depositing a layer comprising an amorphous germanium layer on a substrate. The method comprises heating a substrate, and flowing on the substrate, the precursor compound is represented by <Form 1> to form a seed layer on the surface of the substrate; and heating the substrate, supplying a decane-based gas to the seed layer, and heat The decane-based gas is decomposed to form an amorphous ruthenium layer on the seed layer. R ¹ is ^one of halogen, hydrogen, alkyl, cycloalkyl, phenyl, and fluorenyl, the alkyl group has one carbon to one, and the cycloalkyl has 4 to 7 carbon atoms. One.

According to an embodiment of the present invention, the utility obtained by the precursor compound and the thin film deposition method using the same is explained below.

The precursor compound of the present invention has good thermal stability, is liquid at room temperature, and has high volatility. Therefore, the ruthenium thin film can be effectively deposited by a metal-organic chemical vapor deposition (MOCVD) method and an atomic layer deposition (ALD) method.

According to the thin film deposition method of the embodiment of the present invention, plasma and heat are introduced during the formation of the tantalum film, thereby minimizing the influence on the highly integrated substrate.

The above and other aspects, features and other advantages of the present invention will be more clearly understood from

The first figure is a schematic diagram showing the roughness of an amorphous germanium layer formed by a precursor compound by <Formula 4> in an embodiment of the present invention.

Exemplary embodiments of the present invention will now be described in detail with reference to the drawings.

The present invention relates to a precursor compound and a thin film deposition method using the same, and an embodiment of the present invention will be explained with reference to the accompanying chemical formula. However, the embodiments of the invention may be embodied in different forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and

A thin film for fabricating a semiconductor device refers to a thin metal layer, a semiconductor, or a non-conductor deposited by thermal growth, physical deposition, or chemical reaction. To impart properties that cannot be achieved by the substrate, a film is deposited on the substrate or a material is preformed. The thin film process may mainly include a chemical vapor deposition (CVD) method and a physical vapor deposition (PVD) method.

According to the CVD method, a thin film or an epitaxial layer is formed on a semiconductor device by decomposing a compound in a gaseous state and performing a chemical reaction. One of the reaction gases may be decomposed using heat, plasma energy by laser power, laser light, or ultraviolet light energy, and the energy may promote decomposition of atoms or molecules, or may control the physical properties of the formed film by heating the substrate. nature. According to the CVD method, a crystal layer having high purity without defects can be obtained at a relatively low temperature, and an amorphous material can be obtained. In addition, the CVD method can form various films and can easily control different stoichiometric compositions. The CVD method includes an atmospheric pressure CVD (APCVD) method and a low pressure CVD (low) Pressure CVD; LPCVD) method, plasma enhanced CVD (PECVD) method, energy enhanced CVD (EECVD) method, and the like. According to the MOCVD method, an organometallic complex is encompassed in a raw material gas.

The ALD system evolved from the CVD process, which grows thin films by increasing the atomic layer one by one. By the ALD method, an extremely thin film can be formed, and a circuit line width process having a nanometer size can be performed.

However, the use of conventional dioxane-deposited tantalum films lags behind the required performance. With a film deposited with dioxane, it is difficult to obtain a good step coverage state, and a highly integrated semiconductor device may form irregular voids.

According to an embodiment of the invention, the precursor compound is used to effectively deposit a film on a substrate using MOCVD or ALD. A precursor compound and oxygen (O ₂ ) may be provided on the substrate to form cerium oxide, and a layer may be formed on the substrate formed on the substrate as will be described later.

Hereinafter, the precursor compound of the embodiment of the present invention will be described in detail with reference to the following chemical formula.

<Formula 1> shows a precursor compound according to an embodiment of the present invention. In <Formula 1>, R ¹ is ^one of a halogen, a hydrogen, an alkyl group, a cycloalkyl group, a phenyl group, and a fluorenyl group. The number of carbon atoms of the alkyl group is one of 1 to 4 (-C ₁ H ₃ to -C ₄ H ₉ ), and the carbon number of the cycloalkyl group is one of 4 to 7 (-C ₄ H ₈ to -C ₇ H ₁₄ ).

The precursor compound is preferably an organic ruthenium precursor compound by the CVD method. The ALD method or the like forms a tantalum film.

<Formula 2> shows a precursor compound according to an embodiment of the present invention, characterized in that R ¹ of <Formula 1> is Cl of a halogen (-F, -Cl, -Br, and -I). Cl has a large negative electrical property and increases the adsorption coefficient of the film surface, thereby increasing the film growth rate.

<Formula 3> shows a precursor compound according to an embodiment of the present invention, characterized in that R ¹ of <Formula 1> is hydrogen (H). Since the precursor compound is reduced in molecular size and molecular weight by <Formula 3>, its volatility can be increased, and its boiling point can be lowered. Therefore, it is easy to provide a precursor in the thin film deposition process.

<Formula 4> shows a precursor compound according to an embodiment of the present invention, characterized in that R ¹ of <Formula 1> is a methyl group (-CH ₃ ). In <Form 4>, it is indicated that the precursor compound has a decreased intermolecular attraction and an increase in its volatility and intermolecular bonding. Due to the improved thermal stability of the precursor compound, the process temperature range of the thin film deposition process can be increased.

<Formula 5> shows a precursor compound according to an embodiment of the present invention, characterized in that R ¹ of <Formula 1> is a phenyl group (-C ₆ H ₅ ). In the formula 5, the precursor compound is obtained, the intermolecular bond becomes strong, and the thermal stability is improved. Due to the improved thermal stability of the precursor compound, the process temperature range of the thin film deposition process is increased.

<Formula 6> shows a precursor compound according to an embodiment of the present invention, characterized in that R ¹ of <Formula 1> is a fluorenyl group (-SiR ² R ³ R ⁴ ). <Formula 6> indicates that the amount of the precursor compound is increased by the thiol group. In addition, the film growth rate increases due to an increase in its volatility.

<Formula 7> shows a precursor compound according to an embodiment of the present invention, wherein R ² of <Formula 6> is hydrogen (H) and R ³ and R ⁴ are a methyl group (-CH ₃ ). <Formula 7> indicates that the precursor compound reduces the molecular weight and increases the vapor pressure.

<Formula 8> shows a precursor compound according to an embodiment of the present invention, wherein R ² to R ⁴ of <Formula 6> are a methyl group (-CH ₃ ). <Formula 8> indicates that the precursor compound has an increased intermolecular bonding force and improved thermal stability, thereby increasing the process temperature range of the thin film deposition process.

The precursor compound of the present invention has good thermal stability, is liquid at room temperature, and has high volatility. Therefore, the precursor compound of the embodiment of the present invention can be used as a precursor of MOCVD method or ALD method to effectively deposit a germanium film, and can be provided together with oxygen (O ₂ ) on a substrate to form germanium dioxide. In addition, the introduction of plasma and heat into the tantalum film process does not affect the highly integrated substrate.

<Reaction 1> and <Reaction 2> are examples of the preparation of the precursor compound of the present invention. However, the precursor compound of the present invention is not limited to <Reaction 1> and <Reaction 2>.

In <Reaction 1>, R ¹ is ^one of a halogen, a hydrogen, an alkyl group, a cycloalkyl group, a phenyl group, and a fluorenyl group. The number of carbon atoms of the alkyl group is one of 1 to 4 (-C ₁ H ₃ to -C ₄ H ₉ ), and the carbon number of the cycloalkyl group is one of 4 to 7 (-C ₄ H ₈ to -C ₇ H ₁₄ ).

In <Reaction 2>, R ¹ is ^one of halogen, hydrogen, alkyl, cycloalkyl, phenyl, and anthracenyl. The number of carbon atoms of the alkyl group is one of 1 to 4 (-C ₁ H ₃ to -C ₄ H ₉ ), and the carbon number of the cycloalkyl group is one of 4 to 7 (-C ₄ H ₈ to -C ₇ H ₁₄ ).

M is selected from the group consisting of lithium (Li), sodium (Na), and potassium (K), and R ⁵ is an alkyl group.

As the solvent of <Reaction 1> and <Reaction 2>, a polar solvent such as diethyl ether, tetrahydrofuran, methylalform or the like may be used, or a nonpolar solvent such as hexane, pentane or the like may be used.

Hereinafter, <Experimental Example 1> and <Experimental Example 2> are experimental examples showing the preparation of the precursor compound by the above <Formula 4>.

<Experimental Example 1>

3 L of methylal, 107.15 g (1 mol) of N-methylaniline and 131.55 g (1.3 mol) of triethylamine were added to a 5 L high pressure reactor, after which Stir at -30 °C. While maintaining the low temperature, 86.5 g (1.3 mol) of monochlorosilane was slowly added, and the temperature was slowly raised to -5 ° C, followed by stirring for 12 hours. The reaction was then terminated.

The reaction was filtered to remove the amine salt to give a pale yellow clear solution. Reduce the solution pressure and remove all solvent to leave a non-sticky yellow liquid. The non-viscous and solvent-free yellow liquid system was distilled under reduced pressure to obtain 68 g of colorless (CH ₃ ) (C ₆ H ₅ ) NSiH ₃ (yield: 49.6%).

<Experimental Example 2>

2 L of diethyl ether and 107.15 g (1 mol) of N-methylaniline were placed in a 5 L high pressure reactor, followed by stirring at -15 °C. Next, 400 ml (1 mol) of hexane containing a 2.5 M N-butyllithium solution (N-butyllithium) was slowly added, followed by stirring at room temperature for 3 hours. The temperature was lowered to -20 ° C, and when this temperature was maintained, 73.2 g (1.1 mol) of monochloromethane was slowly added. Next, the temperature was raised to -5 ° C, followed by stirring for 12 hours. The reaction was then terminated.

The reaction was filtered to remove the lithium salt to give a pale yellow, transparent solution. Reduce the solution pressure and remove all solvent to leave a non-sticky yellow liquid. The non-viscous and solvent-free yellow liquid system was distilled under reduced pressure to obtain 61 g of colorless (CH ₃ ) (C ₆ H ₅ ) NSiH ₃ (yield: 44.5%).

The boiling point of (CH ₃ )(C ₆ H ₅ )NSiH ₃ obtained from <Experimental Example 1> and <Experimental Example 2> at 0.51 torr was about 21 °C.

Meanwhile, the precursor compound is represented by the above <Formula 4>, and a seed layer can be formed, and An amorphous germanium layer can be formed on the seed layer. Specifically, a substrate sample having a thickness of about 100 nm formed on the tantalum substrate is inserted into a chamber of the deposition apparatus. For example, the substrate can be a hafnium oxide layer or a tantalum nitride layer.

Next, the seed layer is formed on the surface of the substrate. The substrate is heated, and the precursor compound is formed on the surface of the substrate by discharging the above-mentioned <Formula 4>. Next, an amorphous germanium layer is formed on the seed layer. The substrate is heated and a decane-based gas such as SiH ₂ , SiH ₄ , SiH ₆ , Si ₂ H ₄ , and Si ₂ H ₆ is supplied to the seed layer on the surface of the heated substrate. The decane-based gas system is thermally decomposed to form an amorphous ruthenium layer on the substrate.

The first figure is a schematic diagram showing the roughness of the amorphous germanium layer formed by the precursor compound in the embodiment of the present invention, wherein the horizontal axis corresponds to the processing time required for forming the seed layer, and the vertical The axis corresponds to the roughness of the amorphous germanium layer. In the first figure, PS214 corresponds to the roughness of the amorphous germanium layer formed by the foregoing method; DIPAS corresponds to the roughness of the germanium layer formed by the same process conditions but with DIPAS instead of the <form 4> precursor compound; And BDEAS replaces the roughness of the layer of the precursor compound of <Form 4> with BDEAS under the same process conditions.

As shown in the first figure, the roughness of the amorphous germanium layer formed by the precursor compound is improved by <Formula 4> as compared with the germanium layer formed by DIPAS and BDEAS. Specifically, when the process time for forming the seed layer is increased to be greater than or equal to 10 seconds, the surface roughness is remarkably improved. An amorphous germanium layer can be used to embed contact holes or lines. When the roughness of the amorphous germanium layer is improved, the step coverage state of the amorphous germanium layer can be improved, and the contact hole or line can be miniaturized.

While the invention has been shown and described with respect to the embodiments of the embodiments

Claims (10)

A precursor compound, which is represented by <Form 1>: Wherein R ¹ is ^one of a halogen, a hydrogen, an alkyl group, a cycloalkyl group, a phenyl group, and a fluorenyl group, the carbon number of the alkyl group being one of 1 to 4, and the carbon number of the cycloalkyl group is 4 To one of seven. The compound of claim 1, wherein R ¹ is a halogen of Cl, and the precursor compound is represented by <Form 2>: The compound of claim 1, wherein R ¹ is hydrogen, and the precursor compound is represented by <Form 3>: <Formula 3> For example, in the scope of claim 1, the compound is a precursor, wherein R ¹ is a methyl group, and the precursor compound is represented by <Form 4>: The compound of claim 1, wherein R ¹ is a phenyl group, and the precursor compound is represented by <Form 5>: The compound of claim 1, wherein R ¹ is a fluorenyl group, and the precursor compound is represented by <Form 6>: <Form 6> A compound according to the sixth aspect of the patent application, wherein R ² is hydrogen, R ³ and R ⁴ are methyl groups, and the precursor compound is represented by <Formula 7>: A compound according to the sixth aspect of the patent application, wherein R ² to R ⁴ are a methyl group, and the precursor compound is represented by <Form 8>: A thin film deposition method using a precursor compound to deposit a film on a substrate using <Formula 1>: <Formula 1> Wherein R ¹ is ^one of a halogen, a hydrogen, an alkyl group, a cycloalkyl group, a phenyl group, and a fluorenyl group, the carbon number of the alkyl group being one of 1 to 4, and the carbon number of the cycloalkyl group is 4 To one of seven. A method for depositing an amorphous germanium layer for depositing a layer comprising an amorphous germanium layer on a substrate, the method comprising: heating the substrate, and flowing on the substrate to represent one of <Formula 1> a precursor compound for forming a layer on the surface of the substrate; and heating the substrate, supplying a decane-based gas to the layer, and thermally decomposing the decane-based gas to form the amorphous layer on the layer, Wherein R ¹ is ^one of a halogen, a hydrogen, an alkyl group, a cycloalkyl group, a phenyl group, and a fluorenyl group, the carbon number of the alkyl group being one of 1 to 4, and the carbon number of the cycloalkyl group is 4 To one of seven.