KR20230157854A - Method of depositing thin films and method of manufacturing memory device - Google Patents

Abstract

According to one embodiment of the present invention, a method of forming a thin film using a surface protection material includes a metal precursor supply step of supplying a metal precursor to the inside of a chamber where a substrate is placed and adsorbing the metal precursor to the substrate; purging the interior of the chamber; And a thin film forming step of supplying a reaction material to the inside of the chamber to react with the adsorbed metal precursor and form a thin film, wherein the method includes supplying the surface protection material to the substrate before the thin film forming step. Supplying a surface protective material to adsorb; And further comprising purging the interior of the chamber, wherein the metal precursor is 1 mole to 3 moles of a compound represented by <Formula 1> or <Formula 2> below, and a compound represented by <Formula 3> below It is formed by mixing 1 mole to 3 moles.
<Formula 1>

In the above <Formula 1>,
<Formula 2>

In <Formula 2>, is selected from aryl groups.
<Formula 3>

In <Formula 3>, R1, R2, and R3 are different from each other, and each independently represents a hydrogen atom, an alkyl group with 1 to 6 carbon atoms, a dialkylamine with 1 to 6 carbon atoms, a cycloamine group with 1 to 6 carbon atoms, and 1 carbon atom. It is selected from alkoxy groups or halogen elements of to 6.

Description

Thin film formation method and manufacturing method of memory device including the same {METHOD OF DEPOSITING THIN FILMS AND METHOD OF MANUFACTURING MEMORY DEVICE}

The present invention relates to a method of forming a thin film and a method of manufacturing a memory device including the same. More specifically, the present invention relates to a method of forming a thin film that is easy to control the thickness of the thin film and has excellent step coverage characteristics by forming a very thin film, and a method of forming a thin film including the same. It relates to a method of manufacturing memory devices.

The existing two-dimensional NAND flash process showed technical limitations in which cell-to-cell interference and leakage phenomena intensified as integration increased within a small area. To overcome these shortcomings, 3D NAND Flash technology that stacks cells vertically has emerged.

The advantage of 3D NAND Flash, which includes a multilayer stack, is that it can significantly reduce interference between cells to improve characteristics, and increase data capacity and reduce costs by increasing the stack. As a result, compared to existing NAND memory devices, it has more than 2 times the write speed, 10 times more durability, and half the power consumption.

However, as the height increases due to ultra-high stacking of 90 or more layers, it becomes more difficult to secure a uniform thin film on the sidewall, and there are limitations such as differences in characteristics between the top and bottom cells. Therefore, there is an increasing demand for a manufacturing method that can form a thin film of uniform thickness with excellent step coverage on a three-dimensional structure with a large aspect ratio.

Additionally, thin films containing aluminum play a very important role in the manufacture of semiconductor devices. Thin films containing aluminum include aluminum films, aluminum nitride films, aluminum carbonitride films, aluminum oxide films, and aluminum oxynitride films, and the aluminum nitride films and aluminum oxide films play an important role as passivation layers, interlayer insulating films, or capacitor dielectric layers. Perform.

Currently, trimethylaluminum (TMA) or triisobutylaluminum is used as a precursor for depositing aluminum-containing thin films, but these materials are explosively flammable and require great care when handling them.

Korean Patent Publication No. 2007-0015958 (2007.02.06.)

The purpose of the present invention is to provide a method for forming a thin film with excellent vaporization characteristics and thermal stability and a method for manufacturing a memory device including the same.

Another object of the present invention is to provide a method of forming a thin film with good step coverage and a method of manufacturing a memory device including the same.

Another object of the present invention is to provide a thin film formation method that can form a thin film of very uniform thickness and facilitate thickness control, and a method of manufacturing a memory device including the same.

Further objects of the present invention will become clearer from the following detailed description.

According to one embodiment of the present invention, a method of forming a thin film using a surface protection material includes a metal precursor supply step of supplying a metal precursor to the inside of a chamber where a substrate is placed and adsorbing the metal precursor to the substrate; purging the interior of the chamber; And a thin film forming step of supplying a reaction material to the inside of the chamber to react with the adsorbed metal precursor and form a thin film, wherein the method includes supplying the surface protection material to the substrate before the thin film forming step. Supplying a surface protective material to adsorb; And further comprising purging the interior of the chamber, wherein the metal precursor is 1 mole to 3 moles of a compound represented by <Formula 1> or <Formula 2> below, and a compound represented by <Formula 3> below It is formed by mixing 1 mole to 3 moles.

<Formula 1>

In the above <Formula 1>,

<Formula 2>

In <Formula 2>, is selected from aryl groups.

<Formula 3>

In <Formula 3>, R1, R2 and R3 are different from each other and each independently represents a hydrogen atom, an alkyl group with 1 to 6 carbon atoms, a dialkylamine with 1 to 6 carbon atoms, a cycloamine group with 1 to 6 carbon atoms, and 1 carbon atom. It is selected from alkoxy groups or halogen elements of to 6.

The metal precursor may be formed by mixing ethyl methyl sulfide, ethyl propyl ether, or tetrahydrofuran with trimethyl aluminum.

The surface protection material may be represented by the following <Formula 4>.

<Formula 4>

In <Formula 4>, n is each independently an integer of 0 to 6, It is selected from an alkyl group with 1 to 6 carbon atoms, an alkoxy group with 1 to 6 carbon atoms, and an alkylthio group with 1 to 6 carbon atoms.

The thin film may be any one of aluminum oxide, aluminum nitride, and aluminum sulfide.

The thin film forming method may be carried out at 50 to 700°C.

According to an embodiment of the present invention, a method of manufacturing a volatile memory device may include the thin film forming method described above.

According to an embodiment of the present invention, a method of manufacturing a non-volatile memory device may include the thin film forming method described above.

The reactant may be any one of O3, O2, and H2O.

According to one embodiment of the present invention, a thin film with good step coverage can be formed. The surface protective material has a similar behavior to the metal precursor during the process, and is adsorbed at a high density at the top (or inlet side) in a high aspect ratio structure and at a low density at the bottom (or inside), and in the subsequent process, the metal precursor is absorbed. Prevents adsorption. Therefore, the metal precursor can be uniformly adsorbed within the structure.

In particular, with excellent step coverage, it is possible to form a highly pure thin film without impurities while reducing the difference in characteristics of the top and bottom cells even in an ultra-high stacked structure, and improve the electrical characteristics and reliability of the device.

In addition, it can prevent the aluminum precursor from spontaneously igniting due to exposure to air, and has excellent thermal stability, so it can be delivered to the surface of the substrate in a stable gas phase.

In particular, by maximizing the effect by introducing it together with a surface protection material, the deposition thickness per cycle can be minimized to facilitate thickness control, and the deposited thin film can secure excellent uniformity and step coverage. You can.

1 is a flowchart schematically showing a thin film forming method according to an embodiment of the present invention.
Figure 2 is a graph schematically showing the supply cycle according to an embodiment of the present invention.
Figure 3 is a graph showing the weight change after exposure to outdoor air for Examples 1 and 2.
Figure 4 is a graph showing the results of mixing the precursor TMA corresponding to Comparative Example 1-1 and the surface protection material TMOF in liquid phase.
Figure 5 is a graph showing the results of mixing the precursor TMA-THF corresponding to Example 2-1 and the surface protection material TMOF in liquid phase.
Figures 6 and 7 show GPC (Growth Per Cycle) of an aluminum oxide film as precursor feeding time increases at the same deposition temperature.
Figure 8 is a graph showing the XPS Depth Profile for analyzing the surface of an aluminum oxide film according to an embodiment of the present invention.
Figure 9 shows the results of confirming step coverage by depositing an aluminum oxide film on a pattern wafer according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the attached FIGS. 1 to 9. Embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as limited to the embodiments described below. These embodiments are provided to explain the present invention in more detail to those skilled in the art. Therefore, the shape of each element shown in the drawing may be exaggerated to emphasize a clearer explanation.

The conventional precursor-only process has a problem of poor step coverage because the thin film is not uniform, such as the upper (or entrance side) thicker film and the lower (or inner side) thin film in the high aspect ratio structure.

However, the surface protection material described below behaves the same as the metal precursor, and prevents the metal precursor from being adsorbed in the subsequent process while adsorbed at a higher density on the upper part of the structure than on the lower part, thereby creating a thin film of uniform thickness within the structure. allow it to be formed.

Figure 1 is a flow chart schematically showing a thin film forming method according to an embodiment of the present invention, and Figure 2 is a graph schematically showing a supply cycle according to an embodiment of the present invention. The substrate is loaded into the process chamber, and the ALD process conditions are adjusted. ALD process conditions may include temperature of the substrate or process chamber, chamber pressure, and gas flow rate, and the temperature is 50 to 700°C.

The substrate is exposed to the surface protection material supplied inside the chamber, and the surface protection material is adsorbed on the surface of the substrate. The surface protective material has a similar behavior to the metal precursor during the process, and is adsorbed at a high density on the top (or inlet side) and at a low density on the bottom (or inside) in a high aspect ratio structure, and in the subsequent process, the metal precursor is absorbed. Prevents adsorption.

Specifically, the metal precursor is formed by mixing 1 mole to 3 moles of a compound represented by <Formula 1> or <Formula 2> below and 1 mole to 3 moles of a compound represented by <Formula 3> below.

<Formula 1>

In the above <Formula 1>,

<Formula 2>

In <Formula 2>, is selected from aryl groups.

In <Formula 2>, when X=O, n=3, and R1 to R4 are hydrogen atoms, it corresponds to tetrahydrofuran.

<Formula 3>

In <Formula 3>, R1, R2 and R3 are different from each other and each independently represents a hydrogen atom, an alkyl group with 1 to 6 carbon atoms, a dialkylamine with 1 to 6 carbon atoms, a cycloamine group with 1 to 6 carbon atoms, and 1 carbon atom. It is selected from alkoxy groups or halogen elements of to 6.

Additionally, the metal precursor may be formed by mixing ethyl methyl sulfide, ethyl propyl ether, or tetrahydrofuran with trimethyl aluminum.

Additionally, the surface protective material may be represented by the following <Formula 4>.

<Formula 4>

In <Formula 4>, n is each independently an integer of 0 to 6, It is selected from an alkyl group with 1 to 6 carbon atoms, an alkoxy group with 1 to 6 carbon atoms, and an alkylthio group with 1 to 6 carbon atoms.

Afterwards, a purge gas (for example, an inert gas such as Ar) is supplied to the inside of the chamber to remove or purify non-adsorbed surface protection materials or by-products.

Thereafter, the substrate is exposed to the metal precursor supplied inside the chamber, and the metal precursor is adsorbed on the surface of the substrate. At this time, the precursor supply step is performed at 50 to 700°C.

For example, the surface protection material described above is adsorbed more densely at the top of the structure than at the bottom, and the metal precursor cannot be adsorbed at the location where the surface protection material is adsorbed. That is, the conventional metal precursor was adsorbed more densely at the top of the structure than at the bottom, showing a high density. However, as in the present example, the surface protection material was densely adsorbed at the top of the structure, preventing the adsorption of the metal precursor. can be uniformly adsorbed to the top/bottom of the structure without being overly adsorbed to the top of the structure, and can improve the step coverage of the thin film described later.

Thereafter, a purge gas (for example, an inert gas such as Ar) is supplied to the inside of the chamber to remove or purify the non-adsorbed metal precursor or by-product.

Thereafter, the substrate is exposed to the reaction material supplied inside the chamber, and a thin film is formed on the surface of the substrate. The reactant reacts with the metal precursor layer to form a thin film. The reactant may be O3, O2, or H2O gas, and a metal oxide film may be formed through the reactant. At this time, the reactive material oxidizes the adsorbed surface protection material and is separated and removed from the surface of the substrate. The thin film formation step is carried out at 50 to 700° C., and the thin film may be any one of aluminum oxide, aluminum nitride, and aluminum sulfide.

Afterwards, a purge gas (for example, an inert gas such as Ar) is supplied to the inside of the chamber to remove or purify non-adsorbed surface protection materials/unreacted materials or by-products.

Meanwhile, it has been previously described that the surface protection material is supplied before the metal precursor, but unlike this, the surface protection material may be supplied after the metal precursor or may be supplied both before and after the metal precursor.

- Comparative Example 1: TMA deposition results

An aluminum oxide film was formed on a silicon substrate. An aluminum oxide film was formed through the ALD process, the ALD process temperature was 250 to 400°C, and O3 gas was used as the reaction material.

The process of forming an aluminum oxide film through the ALD process is as follows, and the process below was performed as one cycle.

1) Using Ar as a carrier gas, supply the aluminum precursor TMA (Trimethylaluminium) to the reaction chamber at room temperature and adsorb the aluminum precursor to the substrate.

2) Supply Ar gas into the reaction chamber to remove unadsorbed aluminum precursors or by-products

3) Supply O3 gas to the reaction chamber to form a monolayer

4) Supply Ar gas into the reaction chamber to remove unreacted substances or by-products

- Comparative Example 1-1: Deposition results using TMA and surface protection material TMOF

An aluminum oxide film was formed on a silicon substrate using TMOF (Trimethyl orthoformate) according to the above <Chemical Formula 4> as a surface protection material.

The process of forming an aluminum oxide film through the ALD process is as follows, and the process below was performed as one cycle.

1) Supply surface protection material into the reaction chamber and adsorb to the substrate

2) Supply Ar gas into the reaction chamber to remove unadsorbed surface protective substances or by-products.

3) Using Ar as a carrier gas, supply the aluminum precursor to the reaction chamber at room temperature and adsorb the aluminum precursor to the substrate.

4) Supply Ar gas into the reaction chamber to remove unadsorbed aluminum precursors or by-products

5) Supply O3 gas to the reaction chamber to form a monolayer

6) Supply Ar gas into the reaction chamber to remove unreacted substances or by-products

- Example 1: Manufacturing and deposition results of TMA-EMS

An Al precursor was formed by mixing EMS (Ethyl methyl sulfide) and TMA according to <Formula 1> of the present invention. In a glove box at room temperature, 10.56 g (0.139 mol) of ethyl methyl sulfide was added to a 500 ml round flask, and 5 g (0.069 mol) of trimethyl aluminum was added very slowly to obtain the precursor TMA-EMS.

It was confirmed that the chemical shift peaks of δ = 2.19ppm, 1.76ppm, and 1.20ppm derived from EMS did not change in shape even after the formation of the precursor and moved to 2.05ppm, 1.58ppm, and 0.85ppm, respectively, forming a stable material.

An aluminum oxide film was formed on a silicon substrate using the manufactured TMA-EMS. An aluminum oxide film was formed through the ALD process, the ALD process temperature was 250 to 400°C, and O3 gas was used as the reaction material.

The process of forming an aluminum oxide film through the ALD process is as follows, and the process below was performed as one cycle.

1) Using Ar as a carrier gas, supply the aluminum precursor TMA-EMS to the reaction chamber at room temperature and adsorb the aluminum precursor to the substrate.

2) Supply Ar gas into the reaction chamber to remove unadsorbed aluminum precursors or by-products

3) Supply O3 gas to the reaction chamber to form a monolayer

4) Supply Ar gas into the reaction chamber to remove unreacted substances or by-products

- Example 1-1: Deposition results using TMA-EMS and surface protection material TMOF

An aluminum oxide film was formed on a silicon substrate using TMOF (Trimethyl orthoformate) according to the above <Chemical Formula 4> as a surface protection material.

The process of forming an aluminum oxide film through the ALD process is as follows, and the process below was performed as one cycle.

1) Supply surface protection material into the reaction chamber and adsorb to the substrate

2) Supply Ar gas into the reaction chamber to remove unadsorbed surface protective substances or by-products.

3) Using Ar as a carrier gas, supply the aluminum precursor to the reaction chamber at room temperature and adsorb the aluminum precursor to the substrate.

4) Supply Ar gas into the reaction chamber to remove unadsorbed aluminum precursors or by-products

5) Supply O3 gas to the reaction chamber to form a monolayer

6) Supply Ar gas into the reaction chamber to remove unreacted substances or by-products

- Example 2: Manufacturing and deposition results of TMA-THF

An Al precursor was formed by mixing THF (Tetrahydrofuran) and TMA according to <Formula 2> of the present invention. 10 g (0.139 mol) of tetrahydrofuran was added to a 500 ml round flask in a glove box at room temperature, and 10 g (0.139 mol) of trimethyl aluminum was added very slowly to obtain the precursor TMA-THF.

It was confirmed that the chemical shift peaks of δ=3.57ppm and 1.42ppm derived from EMS did not change in shape even after the formation of the precursor and shifted to 3.35ppm and 0.96ppm, respectively, forming a stable material.

An aluminum oxide film was formed on a silicon substrate using the prepared TMA-THF. An aluminum oxide film was formed through the ALD process, the ALD process temperature was 250 to 400°C, and O3 gas was used as the reaction material.

The aluminum oxide film formation process through the ALD process was carried out using the following process as one cycle.

1) Using Ar as a carrier gas, supply the aluminum precursor TMA-THF to the reaction chamber at room temperature and adsorb the aluminum precursor to the substrate.

2) Supply Ar gas into the reaction chamber to remove unadsorbed aluminum precursors or by-products

3) Supply O3 gas to the reaction chamber to form a monolayer

4) Supply Ar gas into the reaction chamber to remove unreacted substances or by-products

- Example 2-1: Deposition results using TMA-THF and surface protection material TMOF

An aluminum oxide film was formed on the silicon substrate using TMOF (Trimethyl orthoformate) according to the above <Chemical Formula 4> as a surface protection material.

The process of forming an aluminum oxide film through the ALD process is as follows, and the process below was performed as one cycle.

1) Supply surface protection material into the reaction chamber and adsorb to the substrate

2) Supply Ar gas into the reaction chamber to remove unadsorbed surface protective substances or by-products.

3) Using Ar as a carrier gas, supply the aluminum precursor to the reaction chamber at room temperature and adsorb the aluminum precursor to the substrate.

4) Supply Ar gas into the reaction chamber to remove unadsorbed aluminum precursors or by-products

5) Supply O3 gas to the reaction chamber to form a monolayer

6) Supply Ar gas into the reaction chamber to remove unreacted substances or by-products

- Thermal analysis

Referring to [Table 1] below, it can be seen that both TMA-EMS and TMA-THF have excellent vaporization characteristics and the residual amount is less than 0.1%, leaving no impurities in the thin film. In addition, the decomposition temperature was shown to be over 340°C, showing improved thermal stability by effectively blocking the Al-Al interaction between TMA as organic molecules compared to TMA alone, and confirming that it can be delivered to the substrate surface in a stable gas phase. You can.

T1/2(℃) TGA Residue(%) DSC decomposition temperature (℃) TMA 66 < 0.1 319 TMA-EMS 99 < 0.1 343 TMA-THF 138 < 0.1 353

- Outdoor exposure test

Figure 3 is a graph showing the weight change after exposure to outdoor air for Examples 1 and 2. It was confirmed that both precursors had extremely reduced flammability in the air and did not ignite in the air and existed in a liquid state. The suppression of spontaneous ignition can be seen as the effect of forming a very stable material by completely blocking the empty P orbital of Al by organic molecules.

It can be seen that both precursors have a very slow weight loss and a slow oxidation reaction rate. The outdoor exposure test can be viewed as similar to a chemical reaction in which a precursor adsorbs on a surface. When exposed to outdoor air, the precursor reacts with H2O in the atmosphere and undergoes a chemical reaction in which the Al-C bond is broken and replaced by an Al-O bond. This is a reaction in which the precursor meets the -OH* terminated surface of the oxide film and the ligand falls off and adsorbs. Because they are very similar. Therefore, it can be inferred that the decrease in reactivity of the Al precursor in the air will also occur in the surface reaction.

Figure 4 is a graph showing the results of mixing the precursor TMA corresponding to Comparative Example 1-1 and the surface protection material TMOF in liquid phase. In order to simulate the reaction with the surface protection material on the surface, the precursor corresponding to Comparative Example 1-1 and the surface protection material were mixed in liquid form.

Slowly add 1 equivalent of Trimethyl Aluminum to 6 equivalents of Trimethyl orthoformate and stir thoroughly. The mixed solution was analyzed by 1H NMR (C6D6) and peak assigned.

TMOF, HC(OCH ₃ ) ₂ : δ 4.82 (s), 3.12 (s)

(CH ₃ ) ₂ Al(OCH ₃ ): δ 3.05 (s), -0.57 (s)

CH ₃ CH(OCH ₃ ) ₂ : δ 4.42 (m), 3.10 (s), 1.17 (d)

Due to the addition of an excessive amount of trimethyl orthoformate, δ 4.82 and 3.12 resulting from unreacted surface protection material were confirmed, and the product peak formed by the ligand substitution reaction of the precursor and surface protection material was confirmed. All δ -0.36 resulting from Trimethyl Aluminum before reaction disappeared, confirming complete reaction.

Figure 5 is a graph showing the results of mixing the precursor TMA-THF corresponding to Example 2-1 and the surface protection material TMOF in liquid phase. The precursor corresponding to Example 2-1 and the surface protection material were mixed in liquid form.

Slowly add 1 equivalent of TMA-THF to 1 equivalent of Trimethyl orthoformate and stir thoroughly. The mixed solution was analyzed by 1H NMR (C6D6) and peak assigned.

TMOF, HC(OCH ₃ ) ₂ : δ 4.82 (s), 3.12 (s)

TMA-THF: δ 3.43 (m), δ 1.16 (m), -0.39 (s)

(CH ₃ ) ₂ Al(OCH ₃ ): δ 3.05 (s), -0.57 (s)

CH ₃ CH(OCH ₃ ) ₂ : δ 4.42 (m), 3.10 (s), 1.17 (d)

The peak of the product formed from the ligand substitution reaction of the precursor and the surface protective material was confirmed to be the same as the previous result. However, unlike all the Trimethyl Aluminum precursors that reacted and disappeared, TMA-THF and Trimethyl orthoformate peaks that did not react were confirmed. This can also be interpreted as the reactivity of TMA-THF and the surface protection material being greatly reduced, and the surface reaction during deposition also reduces the sticking coefficient and increases diffusion on the surface, resulting in improved step coverage compared to the existing precursor. It can be expected that improvements can be made.

[Table 2] below shows the GPC (Growth Per Cycle) of the aluminum oxide film according to the comparative example and Examples 1 and 2 of the present invention.

precursor surface protection material deposition speed
(Å/cycle) Precursor contrast
Deposition rate reduction rate (%) Comparative Example 1 TMA - 0.81 - Comparative Example 1-1 TMOF 0.56 30.9% Example 1 TMA-EMS - 0.73 - Example 1-1 TMOF 0.22 69.9% Example 2 TMA-THF - 0.65 - Example 2-1 TMOF 0.20 69.2%

Comparing the GPC of Al precursors without using a surface protection material, it can be seen that the GPC of Examples 1 and 2 decreased by 26% and 23%, respectively, compared to the use of TMA alone. This can be interpreted as a decrease in the reactivity of the precursor due to the Al blocking effect and a decrease in accessibility of the Al center and surface -OH* due to the increase in size compared to TMA.

This decrease in reactivity with the surface -OH* termination group leads to a decrease in the sticking coefficient and an increase in diffusion on the surface, which can form a uniform film and ultimately improve uniformity and step coverage. You can.

It can be seen that the GPC reduction of Al precursors using surface protection materials is further maximized. In Comparative Example 1-1, the reduction rate when only the surface protection material was applied was 30%, whereas in Example 2-1, when both the TMA-THF precursor and the surface protection material of this patent were applied, the reduction rate increased significantly to a high of 70%. there is.

Assuming that the total thickness of the dielectric film in the ZrO ₂ /Al ₂ O ₃ /ZrO ₂ composite dielectric film of DRAM is 50 Å and that Al 2 O 3 of Example 2-1 is used for about 3 cycles, the EOT of the dielectric film is 5.21 Å, and the TMA of Comparative Example 1 A scaling down of approximately 12% compared to standalone use can be realized.

Figures 6 and 7 show GPC (Growth Per Cycle) of an aluminum oxide film as precursor feeding time increases at the same deposition temperature.

In the comparative example of Figure 6, the GPC to which the surface protection material was applied continued to increase as the precursor feeding time increased, resulting in poor saturation characteristics and difficult control. On the other hand, in the example of Figure 7, the GPC applied with a surface protection material has a very low GPC compared to the existing precursor-only process, and the GPC change is very small even when the precursor feeding time increases, showing saturation characteristics and being suitable for the ALD process.

Figure 8 is a graph showing the XPS Depth Profile for analyzing the surface of an aluminum oxide film according to an embodiment of the present invention. The carbon concentration in the thin film was 0%, forming a thin film without impurities.

Figure 9 shows the results of confirming step coverage by depositing an aluminum oxide film on a patterned wafer according to an embodiment of the present invention (Aspect ratio 20:1). It was confirmed that all examples showed excellent characteristics with 100% step coverage.

In conclusion, by applying the Al precursor and surface protection material of the present invention, a high GPC reduction effect can be obtained, which not only achieves precise thickness control and excellent step coverage, but also improves the electrical characteristics and reliability of the device. there is. In addition, it is possible to form a thin film of high purity without impurities and thinner than the thickness of a single monolayer that can be obtained by the existing ALD process.

Although the present invention has been described in detail above through examples, other forms of embodiments are also possible. Therefore, the technical spirit and scope of the claims set forth below are not limited to the embodiments.

Claims (7)

In a method of forming a thin film using a surface protective material,
A metal precursor supply step of supplying a metal precursor to the inside of a chamber where a substrate is placed and adsorbing the metal precursor to the substrate;
purging the interior of the chamber; and
A thin film forming step of supplying a reaction material to the inside of the chamber to react with the adsorbed metal precursor and form a thin film,
The method is performed before the thin film forming step,
A surface protection material supply step of supplying the surface protection material and adsorbing it to the substrate; and
Further comprising purging the interior of the chamber,
The metal precursor is a surface protective material formed by mixing 1 mole to 3 moles of a compound represented by <Formula 1> or <Formula 2> below and 1 mole to 3 moles of a compound represented by <Formula 3> below. Thin film formation method using .
<Formula 1>

In the above <Formula 1>,
<Formula 2>

In <Formula 2>, is selected from aryl groups.
<Formula 3>

In <Formula 3>, R1, R2, and R3 are different from each other, and each independently represents a hydrogen atom, an alkyl group with 1 to 6 carbon atoms, a dialkylamine with 1 to 6 carbon atoms, a cycloamine group with 1 to 6 carbon atoms, and 1 carbon atom. It is selected from alkoxy groups or halogen elements of to 6. According to paragraph 1,
The metal precursor is,
A method of forming a thin film using a surface protection material, which is formed by mixing ethyl methyl sulfide, ethyl propyl ether, or tetrahydrofuran with trimethyl aluminum. According to paragraph 1,
A method of forming a thin film using a surface protection material, wherein the surface protection material is represented by the following <Chemical Formula 4>.
<Formula 4>

In <Formula 4>, n is each independently an integer of 0 to 6, It is selected from an alkyl group with 1 to 6 carbon atoms, an alkoxy group with 1 to 6 carbon atoms, and an alkylthio group with 1 to 6 carbon atoms. According to paragraph 1,
A method of forming a thin film, wherein the thin film is any one of aluminum oxide, aluminum nitride, and aluminum sulfide. According to paragraph 1,
The thin film forming method is carried out at 50 to 700°C. A method of manufacturing a volatile memory device comprising any one of the thin film forming methods according to claims 1 to 5. A method of manufacturing a non-volatile memory device comprising any one of the thin film forming methods according to claims 1 to 5.