Silicon precursor and method for manufacturing silicon-containing film using the same
阅读说明：本技术 硅前体和使用其制造含硅薄膜的方法 (Silicon precursor and method for manufacturing silicon-containing film using the same ) 是由 安宰奭 金瑩恩 昔壮衒 朴正佑 于 2021-05-08 设计创作，主要内容包括：本公开涉及可通过气相沉积被沉积作为薄膜的气相沉积化合物,并且具体地,涉及适用于原子层沉积(ALD)或化学气相沉积(CVD)且可以以高速沉积,特别地通过高温ALD的硅前体以及使用其制造含硅薄膜的方法。(The present disclosure relates to vapor deposition compounds that can be deposited as thin films by vapor deposition, and in particular, to silicon precursors suitable for Atomic Layer Deposition (ALD) or Chemical Vapor Deposition (CVD) and that can be deposited at high speed, particularly by high temperature ALD, and methods of manufacturing silicon-containing thin films using the same.)
1. A method of manufacturing a thin film, the method comprising the step of introducing a vapor deposition precursor comprising a compound represented by the following formula 1 into a chamber:
[ formula 1]
SiX1 n(NR1R2)(4-n)
Wherein
n is an integer in the range of 1 to 3,
X1is any one selected from the group consisting of Cl, Br and I, and
R1and R2Each independently hydrogen, a substituted or unsubstituted, linear or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, or isomers thereof.
2. The method of claim 1, wherein R1And R2Each independently comprises a hydrogen atom selected from the group consisting of,Ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl and isomers thereof.
3. The method according to claim 1, wherein, in formula 1, n is 3, and R is1And R2Each independently is isopropyl.
4. The method of any one of claims 1 to 3, comprising Atomic Layer Deposition (ALD) or Chemical Vapor Deposition (CVD).
5. The method of claim 1, further comprising injecting a compound selected from the group consisting of oxygen (O)2) Water (H)2O), ozone (O)3) Oxygen (O)2) And hydrogen (H)2) Nitrogen (N)2) Ammonia (NH)3) Dinitrogen monoxide (N)2O) and hydrogen peroxide (H)2O2) Any one or more of the group consisting of a reactive gas.
6. The method of claim 1, further comprising the step of depositing at a process temperature of 600 ℃ or greater.
7. A thin film produced by the method of claim 1 and having a surface roughness of 0.2nm or less and 2.5g/cm3Or a greater density.
8. An electronic device comprising the thin film of claim 7.
9. The electronic device according to claim 8, which is any one selected from the group consisting of a semiconductor device, a display device, and a solar cell.
FIELD
The present disclosure relates to vapor deposition compounds that can be deposited as thin films by vapor deposition, and more particularly, to novel silicon precursors suitable for Atomic Layer Deposition (ALD) or Chemical Vapor Deposition (CVD) and useful for manufacturing thin films having superior quality, particularly at high process temperatures, and methods of manufacturing silicon-containing thin films using the same.
Discussion of background
Silicon-containing films are used as semiconductor substrates, diffusion masks, oxidation barriers and dielectric films in semiconductor technology such as microelectronics including RAM (memory and logic chips), flat panel displays such as Thin Film Transistors (TFTs) and solar thermal applications.
In particular, as the integration density of semiconductor devices has increased, silicon-containing films having various properties have been required, and the aspect ratios thereof have been increased. Thus, problems arise in that the deposition of silicon-containing films using conventional precursors does not meet the desired properties.
When a thin film is deposited on a highly integrated semiconductor device using a conventional precursor, problems occur in that it is difficult to achieve excellent step coverage (step coverage) and control of the thickness of the thin film, and impurities are contained in the thin film.
Therefore, in order to deposit high-quality silicon-containing films, various silicon precursors, such as aminosilane, have been studied and developed in addition to conventional silicon precursors, such as silane, disilane, and halosilane.
Widely used aminosilane precursors typically include Butylaminosilane (BAS), bis (tertiary butylamino) silane (BTBAS), dimethyl aminosilane (DMAS), bis (tertiary methylamino) silane (BDMAS), tris (dimethylamino) silane (3-DMAS), diethyl aminosilane (DEAS), bis (diethylamino) silane (BDEAS), dipropyl aminosilane (DPAS), and di-isopropyl aminosilane (DIPAS).
For manufacturing a silicon-containing thin film, Atomic Layer Deposition (ALD) or Chemical Vapor Deposition (CVD) is widely used.
In particular, the use of ALD to form a silicon-containing thin film is advantageous because the thickness uniformity and physical properties of the thin film can be improved, resulting in improved characteristics of semiconductor devices. Due to this advantage, the use of ALD has recently increased dramatically. However, since CVD and ALD have different reaction mechanisms, precursors suitable for application to CVD may not be fabricated into thin films of desired quality when applied to ALD. For this reason, precursors suitable for both CVD and ALD have been increasingly researched and developed.
Meanwhile, patents related to the use of precursors such as tris (dimethylamino) silane (3-DMAS), which is one of aminosilane precursors, include U.S. patent No. 5593741. However, even when 3-DMAS is used as a precursor, high quality thin films cannot be obtained at high process temperatures. In addition, even when a silicon precursor substituted with a halogen element is used, it is effective in low-temperature deposition, but a high-quality thin film cannot be obtained at a high process temperature.
Documents of the prior art
Patent document
(patent document 1) Korean patent application laid-open No. 2011-
(patent document 2) U.S. Pat. No. 5593741
Background
Disclosure of Invention
The present disclosure is directed to novel silicon compounds suitable for Atomic Layer Deposition (ALD) or Chemical Vapor Deposition (CVD).
In particular, it is an object of the present disclosure to provide a silicon precursor including a novel silicon compound, which can ensure ALD behavior at high temperature due to its possible application to high process temperature of 600 ℃ or more, can form a silicon oxide film having low impurity concentration (in particular, impurities such as Cl, C, and N are not detected), can ensure excellent step coverage characteristics and surface characteristics (roughness, etc.), and thus has excellent interface characteristics while having excellent corrosion resistance; and a method for manufacturing a silicon-containing film using the same.
However, the object of the present disclosure is not limited to the above-mentioned object, and other objects not mentioned herein will be clearly understood from the following description by those skilled in the art.
One aspect of the present disclosure provides a method of manufacturing a thin film, the method including the step of introducing a vapor deposition precursor including a compound represented by the following formula 1 into a chamber:
[ formula 1]
SiX1 n(NR1R2)(4-n)
Wherein n is an integer ranging from 1 to 3, X1Is any one selected from the group consisting of Cl, Br and I, and R1And R2Each independently hydrogen, a substituted or unsubstituted, linear or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, or isomers thereof.
Another aspect of the present disclosure provides a method of making a thin film, wherein R1And R2Each independently includes any one selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, and isomers thereof.
Still another aspect of the present disclosure provides a method of manufacturing a thin film, wherein, in formula 1, n is 3, and R is1And R2Each independently is isopropyl.
Yet another aspect of the present disclosure provides a method of manufacturing a thin film, wherein the method is performed by a method selected from among Atomic Layer Deposition (ALD) and Chemical Vapor Deposition (CVD).
Yet another aspect of the present disclosure provides a method of manufacturing a thin film, wherein the method further comprises implanting a dopant selected from the group consisting of oxygen (O)2) Water (H)2O), ozone (O)3) Oxygen (O)2) And hydrogen (H)2) Nitrogen (N)2) Ammonia (NH)3) Dinitrogen monoxide (N)2O) and hydrogen peroxide (H)2O2) Any one or more of the group consisting of a reactive gas.
A further aspect of the present disclosure provides a method of fabricating a thin film, wherein the method further comprises the step of performing the deposition at a process temperature of 600 ℃ or higher.
Another further aspect of the present disclosure provides a film produced by the production method according to the present disclosure and having a surface roughness of 0.2nm or less and 2.5g/cm3Or a greater density of film.
Still another further invention of the present disclosure provides an electronic device including the thin film manufactured according to the present disclosure, the electronic device being any one selected from the group consisting of a semiconductor device, a display device, and a solar cell.
Drawings
Fig. 1 shows the results of Nuclear Magnetic Resonance (NMR) analysis of the precursor of example 1.
FIG. 2 is a graph showing deposition rates when deposited using the precursor of example 1 at each of the process temperatures of 600 deg.C, 700 deg.C, and 750 deg.C (A)/cycle) as a function of injection time for the precursor of example 1 (manufacturing examples 1 to 3).
Fig. 3 depicts a graph showing the results of X-ray photoelectron spectroscopy (XPS) performed to measure the composition of a silicon oxide film (experimental example 1) fabricated by depositing the precursor of example 1 at process temperatures of 600 ℃ (fig. 3a) and 750 ℃ (fig. 3b), respectively.
Fig. 4 depicts Atomic Force Microscope (AFM) and Scanning Electron Microscope (SEM) images of silicon oxide films fabricated by depositing the precursors of example 1 at process temperatures of 600 ℃ (fig. 4a) and 750 ℃ (fig. 4b), respectively, and shows the results of analyzing the surface state of the silicon oxide films, including surface roughness (Ra), by SEM (experimental example 2).
Fig. 5 shows the results of X-ray reflectance (XRR) of a silicon oxide film made by depositing the precursor of example 1 at process temperatures of 600 ℃ (fig. 5a) and 750 ℃ (fig. 5b), respectively, and shows the density value of the silicon oxide film as measured by XRR (experimental example 3).
Fig. 6 shows the results of a Scanning Electron Microscope (SEM) conducted to measure the thickness of a silicon oxide film produced by depositing the precursor of example 1 before etching (fig. 6a) and after etching (fig. 6b) (experimental example 4).
Detailed Description
Hereinafter, embodiments and examples of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present disclosure. However, the present disclosure may be presented in a variety of different forms and is not limited to the embodiments and examples described herein and in the drawings. In the drawings, portions irrelevant to the description are omitted for clarity of description of the present disclosure.
One aspect of the present disclosure provides a method of manufacturing a thin film, the method including the step of introducing a vapor deposition precursor including a compound represented by the following formula 1 into a chamber:
[ formula 1]
SiX1 n(NR1R2)(4-n)
Wherein n is an integer ranging from 1 to 3, X1Is any one selected from the group consisting of Cl, Br and I, and R1And R2Each independently hydrogen, a substituted or unsubstituted, linear or branched, saturated or unsaturated hydrocarbon group having 1 to 4 carbon atoms, or isomers thereof.
Preferably, R1And R2May be each independently any one selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl and isomers thereof.
More preferably, in formula 1, n may be 3 but is not limited thereto, and R1And R2May each independently be an isopropyl group but is not limited thereto.
The step of introducing the vapor deposition precursor into the chamber may include, but is not limited to, a physisorption step, a chemisorption step, and both physisorption and chemisorption steps.
In one embodiment of the present disclosure, the vapor deposition may include, but is not limited to, Atomic Layer Deposition (ALD) or Chemical Vapor Deposition (CVD), and the chemical vapor deposition may include, but is not limited to, Metal Organic Chemical Vapor Deposition (MOCVD) or low-pressure chemical vapor deposition (LPCVD).
In one embodiment of the present disclosure, the method of manufacturing a thin film may further include implanting a dopant selected from the group consisting of oxygen (O)2) Water (H)2O), ozone (O)3) Oxygen (O)2) And hydrogen (H)2) Nitrogen (N)2) Ammonia (NH)3) Dinitrogen monoxide (N)2O) and hydrogen peroxide (H)2O2) Any one or more of the group consisting of a reactive gas.
In addition, various oxygen-containing reactants, nitrogen-containing reactants, or carbon-containing reactants may also be used depending on the desired properties of the film, although the scope of the disclosure is not limited in this respect.
In one embodiment of the present disclosure, the method of manufacturing a thin film may be performed at a high temperature. The precursor may be deposited at a process temperature of 300 ℃ to 800 ℃, preferably 600 ℃ to 800 ℃.
When a conventional silicon precursor is used at a high process temperature of 600 ℃ or more, it is difficult to control the film thickness, and a high-quality film having desired characteristics is not provided. However, the novel silicon precursor of the present disclosure is thermally stable even at 600 ℃ or more, and thus can provide a thin film having excellent quality even in a high-temperature process.
Another aspect of the present disclosure provides a thin film manufactured by the method of manufacturing a thin film and having a surface roughness of 0.2nm or less and 2.5g/cm3Or greater, preferably 2.55g/cm3Or a higher density of high purity amorphous silicon oxide films. Depending on the choice of reactants, the thin film may be provided as various thin films such as an oxide film, a nitride film, a carbide film, a carbonitride film, and an oxynitride film. In addition, due to its surface characteristics and density, the thin film is expected to have excellent interface characteristics and corrosion resistance.
Still another aspect of the present disclosure provides a multilayer film comprising a film made according to the present disclosure.
Yet another aspect of the present disclosure provides an electronic device including a thin film made according to the present disclosure. The electronic device may be any one selected from the group consisting of a semiconductor device, a display device, and a solar cell. In particular, the thin film may exhibit excellent characteristics as a tunnel oxide film of a 3D-NAND memory device.
Hereinafter, the present disclosure will be described in more detail with reference to examples, but the scope of the present disclosure is not limited to these examples.
[ example 1]Diisopropylamino trichlorosilane (C)6H14Cl3NSi) is generated
Mixing SiCl4(1.0eq.) was placed in a flask and pentane (12 e)q.) dilution and then cooling in a water bath maintained at 0 ℃. While stirring the resulting solution, diisopropylamine (2.87eq.) diluted in pentane (6eq.) was slowly added to the solution. After the addition was complete, the mixture was stirred at room temperature for 15 hours. After completion of the reaction, the reaction mixture was filtered, and the filtrate solution was boiled at atmospheric pressure to remove the solvent. The obtained liquid was purified under reduced pressure to obtain a colorless transparent liquid.
The reaction scheme for the synthesis of diisopropylaminotrichlorosilane and the chemical structure of diisopropylaminotrichlorosilane are shown in the following reaction scheme and chemical structural formula, and as shown in FIG. 1 by1H-NMR confirmed the chemical structure of diisopropylaminotrichlorosilane.
[ reaction scheme and chemical Structure ]
In addition, the obtained compound had a molecular weight of 234.63g/mol, was in a colorless liquid state at room temperature, and had a boiling point of 205 ℃. The compounds can be easily introduced into the process chamber by high vapor pressure and can provide sufficient amounts of precursor in a short time.
Production examples 1 to 3
The compound produced in example 1 above was deposited using an Atomic Layer Deposition (ALD) system, thus producing a silicon oxide film. The substrate used in this experiment was a bare Si wafer. Prior to deposition, the bare Si wafer was sequentially sonicated in acetone, ethanol and DI water for 10 minutes each, and then the native oxide on the bare Si wafer was treated by soaking in a 10% HF solution (HF: H)2O is 1: 9) the middle 10 seconds are removed.
Specifically, atomic layer deposition is performed for a plurality of cycles, each consisting of the following sequential steps: the silicon precursor of example 1 was implanted for X seconds; purging the precursor with Ar for 10 seconds; injecting reaction gas for 5 seconds; and purging the reaction gas with Ar for 10 seconds.
In the step of injecting the silicon precursor of example 1 for X seconds, X was set to 1 to 12 seconds, a carrier gas argon (Ar) for the precursor was injected at a flow rate of 200sccm, and deposition of the precursor was performed at a process temperature ranging from 600 ℃ to 850 ℃.
All vessels were heated to a temperature of 40 ℃ and Ar for purging was injected at a flow rate of 2,000 sccm.
In addition, hydrogen (H)2) Gas and oxygen (O)2) Gas (H)2+O2) The mixture of (a) is used as a reaction gas. The silicon oxide thin film was manufactured at the process temperatures of 600 ℃ (manufacturing examples 1-1 to 1-5), 700 ℃ (manufacturing examples 2-1 to 2-5) and 750 ℃ (manufacturing examples 3-1 to 3-5).
For the injection of the reaction gas, oxygen (O)2) And hydrogen (H)2) Are supplied into the reaction chamber at flow rates of 1,000sccm and 325sccm, respectively.
The deposition process conditions and the deposition results of manufacturing examples 1 to 3 are shown in the following tables 1 to 3 and fig. 2, respectively.
As shown in fig. 2, it was observed that a thin film was formed by depositing the silicon precursor compound of example 1 even at a higher temperature of 600 c or more. Therefore, it was confirmed that the silicon precursor compound of example 1 and the silicon oxide film formed by depositing the same have excellent thermal stability even at high temperatures.
In addition, from the results of deposition experiments conducted at a process temperature of 850 ℃, it can be confirmed that the ALD process cannot be applied at a process temperature of 850 ℃ or higher due to thermal decomposition of the precursor compound of example 1.
[ Table 1]The precursor compound of example 1 and the reaction gas (H) were used at a process temperature of 600 deg.C2+O2) As a result of the deposition
Table 1 above shows the results of the deposition performed at a process temperature of 600 ℃. It was confirmed that the deposition rate gradually increased as the injection time of the precursor was increased from 1 second to 12 seconds, and a self-limiting reaction was observed around 9 seconds.
[ Table 2 ]]The precursor compound of example 1 and the reaction gas (H) were used at a process temperature of 700 deg.C2+O2) As a result of the deposition
Table 2 above shows the results of the deposition performed at a process temperature of 700 ℃. It was confirmed that as the injection time of the precursor was increased from 1 second to 12 seconds, the deposition rate was increased from 0.84 to 12 secondsPeriod, and a self-limiting reaction was observed around 9 seconds.
[ Table 3]]The precursor compound of example 1 and the reaction gas (H) were used at a process temperature of 750 deg.C2+O2) As a result of the deposition
Table 3 above shows the results of the deposition performed at a process temperature of 750 ℃. It was confirmed that as the injection time of the precursor was increased from 1 second to 12 seconds, the deposition rate was increased from 1.37 to 12 secondsPeriod, and a self-limiting reaction was observed around 9 seconds.
From the deposition results in tables 1 to 3 above and fig. 2, it was confirmed that the deposition rate increased as the injection time of the precursor increased, and the deposition rate increased as the process temperature increased in the deposition experiment performed under the same process conditions except the process temperature.
Experimental example 1]Silicon oxide film (SiO) made from the precursor of example 12) Composition analysis of
Analysis by XPS analysis the mixture of oxygen and hydrogen (H) and the precursor of example 1 deposited by deposition at process temperatures of 600 ℃ and 750 ℃ respectively2+O2) The composition of the silicon oxide film produced, and the results of the analysis are shown in fig. 3.
As shown in fig. 3, the results from XPS analysis of all films manufactured at process temperatures of 600 ℃ (fig. 3a) and 750 ℃ (fig. 3b) can confirm that impurities such as carbon (C), chlorine (Cl) and nitrogen (N) are not detected, suggesting that the formed silicon film has excellent quality and contains no impurities.
Experimental example 2]Silicon oxide film (SiO) made from the precursor of example 12) Surface property of
Deposition of the precursor of example 1 and a mixture of oxygen and hydrogen (H) at process temperatures of 600 ℃ and 750 ℃ respectively, by observing and measuring using an Atomic Force Microscope (AFM) and a Scanning Electron Microscope (SEM)2+O2) The surface roughness (Ra) of the produced silicon oxide film, and the result of the measurement is shown in fig. 4.
As shown in FIG. 4, the measured surface roughness (Ra) ranged from 0.097nm to 0.134nm, indicating that the silicon oxide films all had low roughness ((Ra))Or smaller). In addition, it can be confirmed that the roughness increases as the process temperature increases (FIG. 4a (process temperature: 600 ℃ C., and Ra: 0.097nm) and FIG. 4b (process temperature: 750 ℃ C., and Ra: 0.134 nm)).
This low surface roughness can also be confirmed by SEM.
[ Experimental example 3]Silicon oxide film (SiO) made from the precursor of example 12) Density characteristic of
Mixtures of precursors and oxygen and hydrogen (H) from deposition example 1 at process temperatures of 600 ℃ and 750 ℃ respectively were analyzed by XRR analysis2+O2) The density of the silicon oxide film produced, and the results of the analysis are shown in fig. 5.
From the analysis result in FIG. 5, it was confirmed that the density was 2.574g/cm at the process temperature of 600 ℃3(FIG. 5a), and a process temperature of 750 ℃ with a density of 2.581g/cm3(FIG. 5 b).
As a result of the above analysis, it was confirmed that the density of the produced thin film was close to that of SiO2Bulk (bulk) film density (2.68 g/cm)3) Indicating that the formed film has good quality and good corrosion resistanceAnd (4) sex.
Experimental example 4]Silicon oxide film (SiO) made from the precursor of example 12) Dry etching characteristics of
Deposition of the precursor of example 1 by deposition of a mixture of oxygen and hydrogen (H) at process temperatures of 600 ℃ and 750 ℃ respectively, was analyzed by ellipsometry and Scanning Electron Microscopy (SEM)2+O2) The dry etching characteristics of the produced silicon oxide film, and the results of SEM analysis are shown in fig. 6.
The thickness of the film after completion of deposition and before etching (As-dep) was 30.6nm and 31nm, respectively, As measured by ellipsometry and SEM.
After the deposited film was etched at room temperature for 15 minutes by immersion in a solution of hydrofluoric acid (HF, diluted 1: 200 in distilled water), the thickness of the film was measured by ellipsometry and SEM. As a result, the measured thicknesses were 10.3nm and 8nm, respectively. That is, the thickness values measured by ellipsometry and SEM correspond to etching rates of 1.35 and 1.53, respectively.
As described above, it was confirmed that the novel silicon precursor of the present disclosure is thermally stable even at a high process temperature of 600 ℃ or more and thus applicable to high temperature ALD, and enables precise thickness control using a low thin film growth rate and a uniform deposition rate and has excellent density and etching characteristics. In addition, it was confirmed that a silicon thin film having excellent quality was formed by depositing the novel silicon precursor of the present disclosure.
Due to these excellent characteristics, high-quality silicon thin films are expected to be used as tunnel oxide films for 3D-NAND memory devices in the future. In addition, the high quality silicon thin films can be used in a variety of applications including nano-device and nano-structure fabrication, semiconductor devices, display devices, and solar cells. In addition, the high-quality silicon thin film can be used as a dielectric film or the like in the manufacture of non-memory semiconductor devices.
As described above, the novel silicon precursor according to the present disclosure has a property of not being thermally decomposed even at a high temperature of 600 ℃ or more, particularly, is applied to high temperature ALD, has a uniform deposition rate so as to enable precise thickness control, and has excellent step coverage characteristics.
In addition, silicon-containing films of good quality can be produced by depositing novel silicon precursors according to the present disclosure.
Due to these excellent characteristics, high quality silicon-containing thin films are expected to be used as tunnel oxide films and gap fills for 3D-NAND memory devices in the future. In addition, the high quality silicon-containing thin films can be used in a variety of applications including nanodevice and nanostructure fabrication, semiconductor devices, display devices, and solar cells. In addition, high quality silicon-containing films can also be used as dielectric films for non-memory semiconductor devices.
These physical characteristics provide precursors suitable for Atomic Layer Deposition (ALD) and Chemical Vapor Deposition (CVD), and the precursors are expected to be applied as dielectric materials of semiconductor devices through processes of manufacturing thin films by depositing the same.
It should be understood that the scope of the present disclosure is defined by the appended claims, not the detailed description, and all changes or modifications derived from the meaning and scope of the claims and equivalents thereof fall within the scope of the present disclosure.
- 上一篇：一种医用注射器针头装配设备
- 下一篇：一种铝掺杂氧化镓膜及其制备方法