Shielding compound, thin film formation method using the same, semiconductor substrate and semiconductor device manufactured therefrom

Abstract

The present invention relates to a shielding compound, a method for forming a thin film using the same, and a semiconductor substrate and a semiconductor device manufactured therefrom. A compound having a predetermined structure is provided as a shielding agent, and a deposition layer of uniform thickness is formed on a substrate as a shielding region according to the difference in the adsorption distribution pattern of the shielding agent, thereby reducing the deposition rate of the thin film, appropriately lowering the thin film growth rate, and significantly improving step coverage and thin film thickness uniformity even when a thin film is formed on a substrate having a complex structure, and reducing impurities.

Description

[Technical Field]

[0001] The present invention relates to a shielding compound, a thin film formation method using the same, and semiconductor substrates and semiconductor devices manufactured therefrom. More specifically, it relates to a shielding compound that provides a compound of a predetermined structure as a shielding agent, thereby forming a uniform thickness deposition layer on a substrate as a shielding region due to the difference in the adsorption distribution map of the shielding agent, thereby reducing the deposition rate of the thin film, appropriately lowering the thin film growth rate, and significantly improving step coverage and thickness uniformity of the thin film even when forming a thin film on a substrate with a complex structure, and significantly reducing impurities. The present invention relates to a shielding compound, a thin film formation method using the same, and semiconductor substrates and semiconductor devices manufactured therefrom. [Background technology]

[0002] The increasing integration density of memory and non-memory semiconductor elements is making the microstructure of substrates more complex every day.

[0003] For example, the width and depth of the microstructure (hereinafter also referred to as the "aspect ratio") have increased to 20:1 or more, and 100:1 or more. The larger the aspect ratio, the more difficult it becomes to form a uniform thickness of sedimentary layers along the complex microstructure planes.

[0004] As a result, the importance of step coverage, which defines the thickness ratio of the deposited layers formed in the upper and lower parts of the microstructure, is increasing. When step coverage reaches 90%, it becomes increasingly difficult for the electrical characteristics of the device to be expressed. Since 100% step coverage means that the thickness of the deposited layers formed in the upper and lower parts of the microstructure is the same, technological development is needed to bring the step coverage as close to 100% as possible.

[0005] The aforementioned semiconductor thin film consists of a nitride film, an oxide film, a metal film, and the like. Examples of the nitride film include silicon nitride (SiN), titanium nitride (TiN), and tantalum nitride (TaN); examples of the oxide film include silicon oxide (SiO2), hafnium oxide (HfO2), and zirconium oxide (ZrO2); and examples of the metal film include molybdenum film (Mo) and tungsten (W).

[0006] The aforementioned thin film is generally used as a diffusion barrier between a doped silicon semiconductor layer and interlayer wiring materials such as aluminum (Al) and copper (Cu). However, when a tungsten (W) thin film is deposited onto a substrate, it is used as an adhesion layer.

[0007] On the other hand, as discussed above, in order for a thin film deposited on a substrate to obtain excellent and uniform physical properties, high step-level coverage of the thin film is essential. Therefore, the ALD (atomic layer deposition) process, which utilizes surface reactions, is used more than the CVD (chemical vapor deposition) process, which mainly utilizes gas-phase reactions. However, problems still remain in achieving 100% step-level coverage.

[0008] When increasing the deposition temperature to achieve 100% step coverage, achieving step coverage becomes difficult. Firstly, in a deposition process consisting of a precursor and two types of reactants, increasing the deposition temperature not only leads to a steep increase in the growth rate per particle size (GPC), but even if the ALD process is performed using 300°C to mitigate the increase in GPC due to the increased deposition temperature, the deposition temperature rises during the process, so this is hardly a solution.

[0009] Therefore, methods have been proposed to lower the growth rate of thin films. However, when the deposition temperature is reduced to lower the growth rate of thin films, the amount of residual impurities such as carbon and chlorine in the thin film increases, leading to a significant deterioration of the film quality (see paper J. Vac. Sci. Technol. A, 35(2017) 01B130).

[0010] According to the above-mentioned literature, it was confirmed that process by-products such as chlorides remain in the manufactured thin film, inducing corrosion of metals such as aluminum, and that the formation of non-volatile by-products leads to deterioration of the film quality.

[0011] Therefore, there is a need for a method for forming thin films that enable the formation of thin films with complex structures, have low levels of residual impurities, and greatly improve step coverage and thickness uniformity of the thin film, as well as for the development of semiconductor substrates and semiconductor devices manufactured using this method. [Overview of the Initiative] [Problems that the invention aims to solve]

[0012] To solve the problems of the conventional technology described above, the present invention aims to provide a shielding compound that reduces the deposition rate of a thin film by forming a deposition layer of uniform thickness on a substrate based on the difference in the adsorption distribution diagram of a predetermined shielding agent as a shielding region for thin films, thereby appropriately lowering the thin film growth rate and greatly improving step coverage and thickness uniformity of the thin film even when forming a thin film on a substrate having a complex structure, a thin film formation method using the same, and a semiconductor substrate and semiconductor device manufactured therefrom.

[0013] The present invention aims to improve the density, electrical properties, and dielectric properties of a thin film by improving its crystallinity and oxidation fraction.

[0014] All of the above and other objectives of the present invention can be achieved by the present invention as described below. [Means for solving the problem]

[0015] To achieve the above objectives, the present invention provides a thin-film shielding compound comprising a linear or cyclic saturated or unsaturated hydrocarbon having two or more nitrogen (N), oxygen (O), phosphorus (P), or sulfur (S) atoms, and having 3 to 15 carbon atoms.

[0016] The thin film shielding compound may have a structure that each of the two ends of a central carbon atom double-bonded to oxygen contains nitrogen (N), oxygen (O), phosphorus (P) or sulfur (S), respectively.

[0017] The thin film shielding compound may have a structure that one end of a central carbon atom double-bonded to oxygen contains nitrogen (N), oxygen (O), phosphorus (P) or sulfur (S), and the other end contains carbon (C).

[0018] The thin film shielding compound may be one or more selected from the group consisting of a compound represented by the following Chemical Formula 1 and a compound represented by Chemical Formula 2.

[0019] [Chemical Formula 1]

[0020]

Chemical Structure

[0021] [Chemical Formula 2]

[0022]

Chemical Structure

[0023] (wherein A is oxygen (O), sulfur (S), phosphorus (P), nitrogen (N), -CH, or -CH2,

[0024] B is -OH, -OCH3, -OCH2CH3, -CH2CH3, -SH, -SCH3, or -SCH2CH3,

[0025] R' and R'' are each independently hydrogen, an alkyl group having 1 to 5 carbon atoms, an alkene group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms,

[0026] and n is an integer of 0 to 3.)

[0027] The shielding compound may have a deposition rate reduction ratio represented by the following Numerical Formula 1 of 30% or more.

[0028] [Formula 1]

[0029]

number

[0030] (In the above formula, DRn is the depth rate measured in a thin film manufactured without the shielding compound, and DRw is the depth rate measured in a thin film manufactured with the shielding compound. Here, the depth rate is a value measured using an ellipsometer on thin films with a thickness of 3 to 30 nm under normal temperature and pressure conditions, and is measured in Å / cycle units.)

[0031] The shielding compound may have a refractive index of 1.39 or less, 1.41 to 1.42, 1.43 to 1.44, or 1.45 to 1.46.

[0032] The shielding compound may be selected from one or more compounds represented by the following chemical formulas 1-1 to 1-4 and 2-1 to 2-4.

[0033] [Chemical formulas 1-1 to 1-4]

[0034] [ka]

[0035] [Chemical formulas 2-1 to 2-4]

[0036] [ka]

[0037] The shielding compound may provide a shielding region for an oxide film, a nitride film, a metal film, or a selective thin film thereof.

[0038] The shielding region may be formed on the entire substrate or a portion of the substrate on which the oxide film, nitride film, metal film, or selective thin films thereof are formed.

[0039] When the total area of ​​the entire substrate or a portion of the substrate is considered to be 100% of the total area of ​​the substrate, the shielded area may occupy 10 to 95% of the area, and the unshielded area may occupy the remaining area.

[0040] When the total area of ​​the entire substrate or a portion of the substrate is considered as 100% of the total area of ​​the substrate, the first shielding region may occupy 10 to 95% of the area, the second shielding region may occupy 10 to 95% of the remaining area, and the remaining area may be the unshielded region.

[0041] The thin film may be a laminated film of one or more materials selected from the group consisting of Al, Si, Ti, V, Co, Ni, Cu, Zn, Ga, Ge, Se, Zr, Nb, Mo, Ru, Rh, In, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, La, Ce, and Nd.

[0042] The thin film may be used as a diffusion prevention film, etching stop film, electrode film, dielectric film, gate insulating film, block oxide film, or charge trap.

[0043]

[0044] Furthermore, the present invention provides a thin film formation method characterized by including the step of injecting a shielding compound having a structure represented by the following chemical formula 1 or chemical formula 2 into a chamber to shield the surface of a loaded substrate.

[0045] [Chemical formula 1]

[0046] [ka]

[0047] [Chemical formula 2]

[0048] [ka]

[0049] (A is oxygen (O), sulfur (S), phosphorus (P), nitrogen (N), -CH, or -CH2,

[0050] The aforementioned B is -OH, -OCH3, -OCH2CH3, -CH2CH3, -SH, -SCH3, or -SCH2CH3,

[0051] R' and R'' are independently hydrogen, a C1-C5 alkyl group, a C1-C5 alkene group, or a C1-C5 alkoxy group, and n is an integer from 0 to 3.

[0052]

[0053] Furthermore, the present invention is

[0054] i) A step of vaporizing the aforementioned shielding compound to form a shielding region on the substrate surface loaded into the chamber;

[0055] ii) A step of primary purging the inside of the chamber with purge gas;

[0056] iii) A step of vaporizing the precursor compound and adsorbing it onto the region that has deviated from the shielding region;

[0057] iv) A step of secondary purging the inside of the chamber with purge gas;

[0058] v) The step of supplying reaction gas into the chamber; and

[0059] vi) A method for forming a thin film is provided, which includes the step of tertiarily purging the inside of the chamber with a purge gas.

[0060]

[0061] Furthermore, the present invention is

[0062] i) A step in which the precursor compound is vaporized and adsorbed onto the surface of the substrate loaded into the chamber;

[0063] ii) A step of primary purging the inside of the chamber with purge gas;

[0064] iii) A step of vaporizing the shielding compound to shield the surface of the substrate loaded into the chamber;

[0065] iv) A step of secondary purging the inside of the chamber with purge gas;

[0066] v) The step of supplying reaction gas into the chamber; and

[0067] vi) A method for forming a thin film is provided, which includes the step of tertiarily purging the inside of the chamber with a purge gas.

[0068] The precursor compound is a molecule composed of one or more elements selected from the group consisting of Al, Si, Ti, V, Co, Ni, Cu, Zn, Ga, Ge, Se, Zr, Nb, Mo, Ru, Rh, In, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, La, Ce, and Nd, and may be a precursor with a vapor pressure of more than 0.01 mTorr and 100 Torr or less at 25°C.

[0069] The chamber may be an ALD chamber, a CVD chamber, a PEALD chamber, or a PECVD chamber.

[0070] The shielding compound or precursor compound may include a step of vaporizing and injecting it, followed by plasma post-treatment.

[0071] The amount of purge gas introduced into the chamber in steps ii) and iv) above may be 10 to 100,000 times the volume of the shielding compound introduced.

[0072] The reaction gas is a nitride, an oxidizing agent, or a reducing agent, and the reaction gas, shielding compound, and precursor compound may be transferred into the chamber by VFC, DLI, or LDS.

[0073] The thin film may be a silicon nitride film, a silicon oxide film, a titanium nitride film, a titanium oxide film, a tungsten nitride film, a molybdenum nitride film, a hafnium oxide film, a zirconium oxide film, a tungsten oxide film, or an aluminum oxide film.

[0074] The substrate loaded into the chamber is heated to 100 to 800°C, and the ratio of the amount (mg / cycle) of the shielding compound to the precursor compound introduced into the chamber may be 1:1 to 1:20.

[0075]

[0076] Furthermore, the present invention provides a semiconductor substrate characterized by being manufactured by the thin-film formation method described above.

[0077] The thin film may have a multilayer structure consisting of two or three layers.

[0078]

[0079] Furthermore, the present invention provides a semiconductor device including the aforementioned semiconductor substrate.

[0080] The semiconductor substrate may be a low-resistive metal gate interconnect, a high-aspect-ratio 3D metal-insulator-metal (MIM) capacitor, a DRAM trench capacitor, a 3D gate-all-around (GAA) capacitor, or a 3D NAND flash memory. [Effects of the Invention]

[0081] According to the present invention, there is an effect of providing a shielding compound that reduces the deposition rate of the thin film by forming a shielding region for thin films on the substrate, thereby appropriately lowering the thin film growth rate and improving step coverage even when forming a thin film on a substrate having a complex structure.

[0082] Furthermore, this method more effectively reduces process by-products during thin film formation, preventing corrosion and degradation, and improving the crystallinity of the thin film, thereby improving its electrical properties.

[0083] Furthermore, the reduction of process by-products during thin film formation improves step coverage and thin film density, ultimately leading to the provision of a thin film formation method using this method, as well as semiconductor substrates and semiconductor devices manufactured therefrom. [Brief explanation of the drawing]

[0084] [Figure 1] Figure 1 is a SIMS analysis graph of the HfO2 thin film produced in Example 4.

[0085] [Figure 2] Figure 2 shows the SIMS analysis graph of the HfO2 thin film produced in Comparative Example 4.

[0086] [Figure 3] Figure 3 is a graph showing the ratio analysis of hafnium (Hf) to oxygen (O) in the thin film produced in Comparative Example 3.

[0087] [Figure 4] Figure 4 is a graph showing the hafnium (Hf) to oxygen (O) ratio analysis of the thin film produced in Example 8.

[0088] [Figure 5] Figure 5 shows TEM measurement images of test specimens obtained by horizontally cutting a thin film deposited on a substrate with a complex structure and an aspect ratio of 22:1 under the conditions of Example 4, at a position 100 nm below the top (left diagram) and at a position 100 nm above the bottom (right diagram).

[0089] [Figure 6] Figure 6 shows TEM measurement images of test specimens obtained by horizontally cutting a thin film deposited on a substrate with a complex structure and an aspect ratio of 22:1 under the conditions of Example 5, at a position 100 nm below the top (left diagram) and at a position 100 nm above the bottom (right diagram).

[0090] [Figure 7] Figure 7 shows the XRD crystal patterns of Comparative Example 4 (black) and Example 1 (blue). [Modes for carrying out the invention]

[0091] The shielding compound described herein, the thin film formation method using it, and the semiconductor substrate and semiconductor device manufactured therefrom will be explained in detail below.

[0092] In this document, unless otherwise specified, the term "shielding" means not only reducing, preventing, or blocking the adsorption of precursor compounds for forming thin films onto the substrate, but also reducing, preventing, or blocking the adsorption of process by-products onto the substrate.

[0093] The present inventors have provided a shielding compound for shielding precursor compounds for forming a thin film on the surface of a substrate loaded into a chamber. By providing a compound with a predetermined structure as a shielding agent, a uniform thickness deposition layer is formed as a shielding region that does not remain in the thin film due to the difference in the adsorption distribution map of the shielding agent, thereby forming a relatively sparse thin film. At the same time, the growth rate of the formed thin film is significantly reduced, ensuring the uniformity of the thin film even when applied to substrates with complex structures, greatly improving step coverage, and enabling deposition at particularly thin thicknesses. They have also confirmed that the amount of residual O, Si, metals, metal oxides, and even carbon, which were previously difficult to reduce, has been improved as process by-products. Based on this, they have diligently pursued research on shielding compounds that provide shielding regions, leading to the completion of the present invention.

[0094]

[0095] The shielding compound of the present invention provides a shielding compound for thin films.

[0096] The thin film may, for example, be provided as one or more precursors selected from the group consisting of Al, Si, Ti, V, Co, Ni, Cu, Zn, Ga, Ge, Se, Zr, Nb, Mo, Ru, Rh, In, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, La, Ce, and Nd, or it may provide an oxide film, a nitride film, a metal film, or a shielding region for selective thin films thereof, in which case the effects to be achieved in the present invention can be fully obtained.

[0097] The thin film may have, as specific examples, a film composition of silicon nitride film, silicon oxide film, titanium nitride film, titanium oxide film, tungsten nitride film, molybdenum nitride film, hafnium oxide film, zirconium oxide film, tungsten oxide film, or aluminum oxide film.

[0098] The aforementioned thin film may contain the aforementioned film composition individually or in a selective area, but is not limited to this; it also includes SiH and SiOH.

[0099] The thin film may be used not only as a diffusion prevention film for general use, but also in semiconductor devices as an etching stop film, electrode film, dielectric film, gate insulating film, block oxide film, or charge trap.

[0100]

[0101] The shielding compound is characterized by containing linear or cyclic saturated or unsaturated hydrocarbons having two or more nitrogen (N), oxygen (O), phosphorus (P), or sulfur (S) atoms and having 3 to 15 carbon atoms. In this case, when forming a thin film, it forms a shielding region that does not remain in the thin film, forming a relatively sparse thin film, while simultaneously suppressing side reactions to regulate the thin film growth rate, reducing process by-products within the thin film, thereby reducing corrosion and degradation, improving the crystallinity of the thin film, and enabling the formation of a stoichiometric oxidation state during the formation of a metal oxide film. It also has the effect of greatly improving step coverage and thickness uniformity of the thin film when forming a thin film on a substrate with a complex structure.

[0102] As a specific example, the shielding compound has a structure in which nitrogen (N), oxygen (O), phosphorus (P), or sulfur (S) are contained at both ends of a central carbon atom linked to oxygen by a double bond, resulting in a significant reduction in process by-products, excellent step coverage, improved thin film density, and superior electrical properties of the thin film.

[0103] Here, the structure in which a central carbon atom linked to oxygen by a double bond has nitrogen (N), oxygen (O), phosphorus (P), or sulfur (S) at both ends, respectively, refers to the following unless otherwise specified. [ka]

[0104] As a specific example, the shielding compound has a structure in which one end of a central carbon atom linked to oxygen by a double bond contains nitrogen (N), oxygen (O), phosphorus (P), or sulfur (S), and the other end contains carbon (C). This significantly reduces process by-products, provides excellent step coverage, improves thin film density, and enhances the electrical properties of the thin film.

[0105] Here, the structure in which a central carbon atom linked to oxygen by a double bond has nitrogen (N), oxygen (O), phosphorus (P), or sulfur (S) at one end and carbon (C) at the other end, unless otherwise specified, refers to the following: [ka]

[0106]

[0107] The shielding compound may be one or more compounds selected from those represented by chemical formula 1 and chemical formula 2, for example. In this case, a shielding region that does not remain in the thin film during thin film formation is formed, creating a relatively sparse thin film. At the same time, side reactions are suppressed to adjust the thin film growth rate, process by-products within the thin film are reduced, corrosion and degradation are reduced, the crystallinity of the thin film is improved, and step coverage and thickness uniformity of the thin film can be greatly improved even when forming a thin film on a substrate with a complex structure.

[0108] [Chemical formula 1]

[0109] [ka]

[0110] [Chemical formula 2]

[0111] [ka]

[0112] (A is oxygen (O), sulfur (S), phosphorus (P), nitrogen (N), -CH, or -CH2,

[0113] The aforementioned B is -OH, -OCH3, -OCH2CH3, -CH2CH3, -SH, -SCH3, or -SCH2CH3,

[0114] R' and R'' are independently hydrogen, a C1-C5 alkyl group, a C1-C5 alkene group, or a C1-C5 alkoxy group.

[0115] (The aforementioned n is an integer between 0 and 3.)

[0116] In the aforementioned chemical formula 1, A is oxygen (O) or sulfur (S), preferably oxygen (O). In this case, there are advantages such as a greater reduction in process by-products, excellent step coverage, improved thin film density, and superior electrical, insulating, and dielectric properties of the thin film.

[0117] The R' is an alkyl group having 1 to 3 carbon atoms, preferably an alkyl group having 1 to 2 carbon atoms. In this case, there is a significant reduction in process by-products, excellent step coverage, improved thin film density, and superior electrical, insulating, and dielectric properties of the thin film.

[0118] The aforementioned n is an integer from 1 to 2, preferably an integer of 1.

[0119] In the aforementioned chemical formula 2, B is -OH, -OCH3, -OCH2CH3, -CH2CH3, -SH, -SCH3, or -SCH2CH3. In this case, there are advantages such as a significant reduction in process by-products, excellent step coverage, improved thin film density, and superior electrical properties of the thin film.

[0120] The R'' is an alkyl group having 1 to 3 carbon atoms, preferably an alkyl group having 1 to 2 carbon atoms. In this case, there are advantages such as a greater reduction in process by-products, excellent step coverage, improved thin film density, and superior electrical properties of the thin film.

[0121] The compounds represented by chemical formulas 1 and 2 can improve the efficiency of the vapor deposition process when they have a saturated structure.

[0122] The compounds represented by chemical formulas 1 and 2 may exclude structures containing halogens.

[0123]

[0124] The shielding compound, preferably the compound represented by chemical formula 1 or chemical formula 2, may have a deposition rate reduction rate of 30% or more, specifically 35% or more, preferably 38% or more, as represented by the following formula 1. In this case, a uniform thickness deposition layer is formed as a shielding region that does not remain in the thin film due to the difference in the adsorption distribution diagram of the shielding agent having the aforementioned structure, thereby forming a relatively sparse thin film. At the same time, the growth rate of the formed thin film is significantly reduced, ensuring the uniformity of the thin film even when applied to substrates with complex structures, greatly improving step coverage, and enabling deposition at particularly thin thicknesses. Furthermore, it can provide the effect of improving residual O, Si, metals, metal oxides, and even carbon, which were previously difficult to reduce, as by-products of the process.

[0125] [Formula 1]

[0126]

number

[0127] (In the above formula, DRn is the depth rate measured in a thin film manufactured without the shielding compound, and DRw is the depth rate measured in a thin film manufactured with the shielding compound. Here, the depth rate is a value measured using an ellipsometer on thin films with a thickness of 3 to 30 nm under normal temperature and pressure conditions, and is measured in Å / cycle units.)

[0128] In the above formula 1, the thin film growth rate per cycle with and without the use of a shielding compound represents the thin film deposition thickness (Å / cycle) per cycle, i.e., the deposition rate. For example, the deposition rate can be determined by measuring the final thickness of a thin film with a thickness of 3 to 30 nm using an ellipsometer under room temperature and atmospheric pressure conditions, and then dividing the result by the total number of cycles to obtain the average deposition rate.

[0129] In the aforementioned formula 1, "when no shielding compound is used" means the case in which only a precursor compound is adsorbed onto the substrate during the thin film deposition process to produce a thin film. A specific example of this is the case in the thin film formation method in which the steps of adsorbing the shielding compound and purging the unadsorbed shielding compound are omitted to form a thin film.

[0130]

[0131] The shielding compound may, for example, be a compound represented by chemical formula 1, having a refractive index of 1.4 to 1.42, or 1.43 to 1.5, and more specifically, 1.41 to 1.417, or 1.43 to 1.47, preferably 1.413 to 1.417, or 1.450 to 1.452.

[0132] As an example, the shielding compound may be a compound represented by chemical formula 2, which has a refractive index of 1.39 or less, and more specifically, a compound in the range of 1.3 to 1.39, preferably 1.35 to 1.385.

[0133] In such cases, the difference in the adsorption distribution map of the shielding agent having the aforementioned structure on the substrate creates a uniform thickness deposition layer, forming a shielding region that does not remain in the thin film. This reduces the deposition rate of the thin film, appropriately lowers the thin film growth rate, and significantly improves step coverage and thin film thickness uniformity even when forming a thin film on a substrate with a complex structure. It also has the advantage of effectively protecting the substrate surface by preventing the adsorption of not only thin film precursors but also process by-products, and effectively removing process by-products.

[0134] In particular, because it forms a relatively sparse thin film while simultaneously significantly reducing the growth rate of the formed thin film, it ensures uniformity of the thin film even when applied to substrates with complex structures, greatly improving step coverage. It is especially possible to deposit thin films, and it can provide the effect of improving residual O, Si, metals, metal oxides, and even carbon residues that were previously difficult to reduce as process by-products.

[0135]

[0136] The compound represented by chemical formula 1 can be selected from one or more compounds represented by the following chemical formulas 1-1 to 1-4. In this case, the effect of providing a thin film shielding region and adjusting the growth rate of the thin film is significant, the effect of removing process by-products is also significant, and the effect of improving step coverage and film quality is excellent.

[0137] [Chemical formulas 1-1 to 1-4]

[0138] [ka]

[0139] The compound represented by chemical formula 2 can be selected from one or more compounds represented by the following chemical formulas 2-1 to 2-4. In this case, the effect of providing a thin film shielding region and adjusting the growth rate of the thin film is significant, the effect of removing process by-products is also significant, and the effect of improving step coverage and film quality is excellent.

[0140] [Chemical formulas 2-1 to 2-4]

[0141] [ka]

[0142] The shielding compound can provide a shielding region for thin films.

[0143] As an example, the thin film shielding region may be formed on the entire substrate or a portion of the substrate on which the thin film is formed.

[0144] Furthermore, the thin-film shielding region may, for example, occupy 10 to 95% of the total area of ​​the entire substrate or a portion of the substrate, specifically 15 to 90%, preferably 20 to 85%, more preferably 30 to 80%, even more preferably 40 to 75%, and even more preferably 40 to 70%, with the unshielded region accounting for the remaining area.

[0145] Furthermore, the thin-film shielding region may be such that, when the total area of ​​the entire substrate or a portion of the substrate is considered as 100% of the total area of ​​the substrate, the first shielding region occupies 10 to 95% of the area, specifically 15 to 90%, preferably 20 to 85%, more preferably 30 to 80%, even more preferably 40 to 75%, and even more preferably 40 to 70%, while the second shielding region occupies 10 to 95% of the remaining area, specifically 15 to 90%, preferably 20 to 85%, more preferably 30 to 80%, even more preferably 40 to 75%, and even more preferably 40 to 70%, with the remaining area being the unshielded region.

[0146]

[0147] The aforementioned shielding region for the thin film is characterized by not remaining in the thin film.

[0148] In this case, "no residue" means, unless otherwise specified, the presence of C, Si, N, and halogen elements at a concentration of less than 0.1 atoms (atom%) during component analysis by XPS. More preferably, in a Secondary-ion mass spectrometry (SIMS) measurement method or an X-ray photoelectron spectroscopy (XPS) measurement method in which the substrate is penetrated in the depth direction for measurement, it is preferable that the increase or decrease in signal intensity for each element species does not exceed 5%, considering the increase or decrease in C, N, Si, and halogen impurities before and after using a shielding agent under similar deposition conditions.

[0149] The thin film may, for example, contain a halogen compound at a concentration of 100 ppm or less.

[0150] The thin film may, but is not limited to, be used as an etching stop film, electrode film, dielectric film, gate insulating film, block oxide film, or charge trap.

[0151] The shielding compound may preferably be a compound with a purity of 99.9% or higher, a compound with a purity of 99.95% or higher, or a compound with a purity of 99.99% or higher. For reference, when using a compound with a purity of less than 99%, impurities may remain in the thin film or cause side reactions with precursors or reactants, so it is preferable to use a substance with a purity of 99% or higher whenever possible.

[0152]

[0153] The shielding compound is preferably used in an atomic layer deposition (ALD) process, in which case it has the advantage of effectively protecting the substrate surface as a shielding compound without interfering with the adsorption of the precursor compound, and effectively removing process by-products.

[0154] The shielding compound is preferably a liquid at room temperature (22°C) and has a density of 0.8 to 2.5 g / cm³. 3or 0.8 to 1.5 g / cm³ 3 Furthermore, the vapor pressure (at 20°C) may be 0.1 to 300 mmHg or 1 to 300 mmHg, and within this range, a shielding region is effectively formed, resulting in excellent step coverage, thin film thickness uniformity, and film quality improvement.

[0155] More preferably, the shielding compound has a density of 0.75 to 2.0 g / cm³. 3 Or 0.8 to 1.3 g / cm³ 3 Furthermore, the vapor pressure (at 20°C) may be between 1 and 260 mmHg, and within this range, a shielding region can be effectively formed, resulting in excellent step coverage, thin film thickness uniformity, and film quality improvement.

[0156]

[0157] The present invention provides a thin film formation method that includes a step of injecting a shielding compound having a structure represented by the following chemical formula 1 or chemical formula 2 into a chamber to shield the loaded substrate surface. In this case, a shielding region for the thin film is formed on the substrate, reducing the deposition rate of the thin film and appropriately lowering the thin film growth rate. This has the effect of greatly improving step coverage and thickness uniformity of the thin film, even when forming a thin film on a substrate having a complex structure.

[0158] [Chemical formula 1]

[0159] [ka]

[0160] [Chemical formula 2]

[0161] [ka]

[0162] (A is oxygen (O), sulfur (S), phosphorus (P), nitrogen (N), -CH, or -CH2,

[0163] The aforementioned B is -OH, -OCH3, -OCH2CH3, -CH2CH3, -SH, -SCH3, or -SCH2CH3,

[0164] R' and R'' are independently hydrogen, a C1-C5 alkyl group, a C1-C5 alkene group, or a C1-C5 alkoxy group, and n is an integer from 0 to 3.

[0165]

[0166] In the step of shielding the substrate surface with the shielding compound, the feeding time (sec) of the shielding compound to the substrate surface is preferably 0.01 to 5 seconds, more preferably 0.02 to 3 seconds, even more preferably 0.04 to 2 seconds, and even more preferably 0.05 to 1 second per cycle. Within this range, there is an advantage of a low thin film growth rate, excellent step coverage, and economic efficiency.

[0167] In this description, the feeding time of the shielding compound is based on a chamber volume of 15 to 20 L and a flow rate of 0.1 to 50 mg / cycle, and more specifically, on a chamber volume of 18 L and a flow rate of 0.8 to 20 mg / cycle.

[0168] The thin film formation method may, as a preferred embodiment, include the steps of: i) vaporizing the shielding compound and shielding it to the surface of the substrate loaded into the chamber; ii) primary purging the inside of the chamber with a purge gas; iii) vaporizing the precursor compound and adsorbing it to the surface of the substrate loaded into the chamber; iv) secondary purging the inside of the chamber with a purge gas; v) supplying a reaction gas to the inside of the chamber; and vi) tertiary purging the inside of the chamber with a purge gas. In this case, steps i) to vi) may be considered as a unit cycle and repeated until a thin film of the desired thickness is obtained. When the shielding compound of the present invention is introduced before the precursor compound and adsorbed onto the substrate within one cycle in this way, the thin film growth rate can be appropriately reduced even when deposited at high temperatures, the process by-products generated are effectively removed, the resistivity of the thin film decreases, and the step coverage is greatly improved.

[0169]

[0170] In other preferred embodiments, the thin film formation method may include the steps of: i) vaporizing a precursor compound and adsorbing it onto the surface of a substrate loaded into a chamber; ii) primary purging the inside of the chamber with a purge gas; iii) vaporizing the shielding compound and adsorbing it onto the surface of a substrate loaded into a chamber; iv) secondary purging the inside of the chamber with a purge gas; v) supplying a reaction gas into the inside of the chamber; and vi) tertiary purging the inside of the chamber with a purge gas. In this case, steps i) to vi) may be used as a unit cycle and the cycle may be repeated until a thin film of the desired thickness is obtained. When the shielding compound of the present invention is introduced later than the precursor compound and adsorbed onto the substrate within a single cycle in this way, the shielding compound can act as a growth activator for thin film formation. In this case, the thin film growth rate is increased, the density and crystallinity of the thin film are increased, the resistivity of the thin film decreases, and the electrical properties are greatly improved.

[0171]

[0172] In the thin film formation method of the present invention, as a preferred example, the shielding compound of the present invention can be introduced before the precursor compound within a single cycle and adsorbed onto the substrate. In this case, even when the thin film is deposited at high temperature, the thin film growth rate can be appropriately reduced, significantly reducing process by-products, greatly improving step coverage, increasing the formation of the thin film, reducing the resistivity of the thin film, and having the advantage of greatly improving the thickness uniformity of the thin film even when applied to semiconductor devices with a large aspect ratio, thereby ensuring the reliability of the semiconductor device.

[0173]

[0174] As an example, in the thin film formation method, when the shielding compound is deposited before or after the deposition of the precursor compound, the unit cycle may be repeated 1 to 99,999 times as needed, preferably 10 to 10,000 times, more preferably 50 to 5,000 times, and even more preferably 100 to 2,000 times. Within this range, the desired thin film thickness can be obtained while fully achieving the effects intended to be achieved in the present invention.

[0175]

[0176] The aforementioned precursor compound is a molecule having Al, Si, Ti, V, Co, Ni, Cu, Zn, Ga, Ge, Se, Zr, Nb, Mo, Ru, Rh, In, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, La, Ce, and Nd as the central metal atom, and containing one or more ligands consisting of C, N, O, and H. When the precursor has a vapor pressure of 1 mTorr to 100 Torr at 25°C, the effect of forming a shielding region by the aforementioned shielding compound can be maximized.

[0177] The aforementioned precursor compound is not limited to any compound known in the art, and as an example, a compound containing a cyclopentadienyl group may be used. Specifically, taking hafnium precursor compounds as examples, tris(dimethylamide)cyclopentadienylhafnium (CpHf(NMe2)3) and (methyl-3-cyclopentadienylpropylamino)bis(dimethylamino)hafnium (Cp(CH2)3NM3Hf(NMe2)2) may be used.

[0178] In the present invention, the chamber may, for example, be an ALD chamber, a CVD chamber, a PEALD chamber, or a PECVD chamber.

[0179] In the present invention, the shielding compound or precursor compound may include a step of vaporizing and injecting it, followed by plasma post-treatment. In this case, the growth rate of the thin film can be improved while reducing process by-products.

[0180]

[0181] When the shielding compound is first adsorbed onto the substrate and then the precursor compound is adsorbed, or when the precursor compound is first adsorbed and then the shielding compound is adsorbed, the amount of purge gas introduced into the chamber during the step of purging the unadsorbed shielding compound is not particularly limited as long as it is sufficient to remove the unadsorbed shielding compound. For example, it may be 10 to 100,000 times, preferably 50 to 50,000 times, and more preferably 100 to 10,000 times, and within this range, the unadsorbed shielding compound can be sufficiently removed to form a uniform thin film and prevent deterioration of the film quality. Here, the amounts of purge gas and shielding compound introduced are based on one cycle, and the volume of the shielding compound refers to the volume of vaporized shielding compound vapor.

[0182] As a specific example, if the shielding compound is injected at a flow rate of 1.66 mL / s and an injection time of 0.5 sec (per cycle), and then a purge gas is injected at a flow rate of 166.6 mL / s and an injection time of 3 sec (per cycle) to purge the unadsorbed shielding compound, the amount of purge gas injected is 602 times the amount of shielding compound injected.

[0183]

[0184] Furthermore, the amount of purge gas introduced into the chamber during the purging stage of the unadsorbed precursor compound is not particularly limited as long as it is sufficient to remove the unadsorbed precursor compound. For example, the amount may be 10 to 10,000 times the volume of the precursor compound introduced into the chamber, preferably 50 to 50,000 times, and more preferably 100 to 10,000 times. Within this range, the unadsorbed precursor compound can be sufficiently removed to form a uniform thin film and prevent deterioration of the film quality. Here, the amounts of purge gas and precursor compound introduced are based on one cycle, and the volume of the precursor compound refers to the volume of vaporized precursor compound vapor.

[0185]

[0186] Furthermore, the amount of purge gas introduced into the ALD chamber during the purging stage, which is performed immediately after the reaction gas supply stage, may, for example, be 10 to 10,000 times the volume of reaction gas introduced into the ALD chamber, preferably 50 to 50,000 times, and more preferably 100 to 10,000 times, and the desired effect can be sufficiently obtained within this range. Here, the amounts of purge gas and reaction gas introduced are based on one cycle.

[0187]

[0188] The shielding compound and precursor compound may be transferred into the ALD chamber preferably by VFC, DLI, or LDS, and more preferably by LDS.

[0189] The substrate loaded into the chamber may be heated, for example, to 50 to 400°C, and more specifically, to 50 to 400°C. The shielding compound or precursor compound may be injected onto the substrate without heating or while heated. Depending on the deposition efficiency, the compound may be injected without heating first, and then the heating conditions may be adjusted during the deposition process. For example, it may be injected onto the substrate at 50 to 400°C for 1 to 20 seconds.

[0190]

[0191] The ratio of the amount (mg / cycle) of the shielding compound to the precursor compound introduced into the chamber is preferably 1:1.5 to 1:20, more preferably 1:2 to 1:15, even more preferably 1:2 to 1:12, and even more preferably 1:2.5 to 1:10. Within this range, the effect of improving step coverage and reducing process by-products is greatest.

[0192]

[0193] In the present invention, the precursor compound may, for example, be mixed with a nonpolar solvent and introduced into the chamber. In this case, there is the advantage that the viscosity and vapor pressure of the precursor compound can be easily adjusted.

[0194] The nonpolar solvent may preferably be one or more selected from the group consisting of alkanes and cycloalkanes. In this case, there is an advantage that even if the deposition temperature rises during thin film formation, step coverage is improved, while still containing an organic solvent with low reactivity and solubility that is easy to manage moisture content.

[0195] As a more preferred example, the nonpolar solvent is C1 to C 10Alkanes, or C3 or C 10 It may also contain cycloalkanes, preferably C3 to C3. 10 This is a cycloalkane, which has the advantage of low reactivity and solubility, making moisture management easy.

[0196] In this document, C1, C3, etc., refer to the number of carbon atoms.

[0197] The cycloalkane is preferably C3 to C 10 It may be any monocycloalkane, and among the monocycloalkanes, cyclopentane is preferred in the vapor deposition process because it is a liquid at room temperature and has the highest vapor pressure, but it is not limited to this.

[0198] The aforementioned nonpolar solvent, for example, has a solubility in water (at 25°C) of 200 mg / L or less, preferably 50 to 400 mg / L, and more preferably 135 to 175 mg / L. Within this range, it has the advantage of low reactivity with the precursor compound and easy moisture control.

[0199] The solubility described herein is not particularly limited as long as it is measured according to measurement methods and standards commonly used in the art to which the present invention pertains. For example, a saturated solution may be measured by HPLC.

[0200] The nonpolar solvent may preferably be present in an amount of 5 to 95% by weight, more preferably 10 to 90% by weight, even more preferably 40 to 90% by weight, and most preferably 70 to 90% by weight, relative to the total weight of the precursor compound and the nonpolar solvent combined.

[0201] If the amount of the nonpolar solvent added exceeds the upper limit, it induces impurities, increasing resistance and the value of impurities in the thin film. Conversely, if the amount of the organic solvent added is below the lower limit, there is a disadvantage in that the effect of improving step coverage due to solvent addition and the effect of reducing impurities such as chloride (Cl) ions are reduced.

[0202]

[0203] As an example, in the thin film formation method, when the shielding compound, preferably the compound represented by chemical formula 1 or chemical formula 2, is used, the deposition rate reduction rate represented by the following formula 1 may be 30% or more, specifically 35% or more, preferably 38% or more. In this case, a deposition layer of uniform thickness is formed as a shielding region that does not remain in the thin film due to the difference in the adsorption distribution diagram of the shielding agent having the aforementioned structure, thereby forming a relatively sparse thin film. At the same time, the growth rate of the formed thin film is significantly reduced, ensuring the uniformity of the thin film even when applied to substrates with complex structures, greatly improving step coverage, and enabling deposition at particularly thin thicknesses. Furthermore, it can provide the effect of improving the amount of residual O, Si, metals, metal oxides, and even carbon, which were previously difficult to reduce, as process by-products.

[0204] [Formula 1]

[0205]

number

[0206] (In the above formula, DRn is the depth rate measured in a thin film manufactured without the shielding compound, and DRw is the depth rate measured in a thin film manufactured with the shielding compound. Here, the depth rate is a value measured using an ellipsometer on thin films with a thickness of 3 to 30 nm under normal temperature and pressure conditions, and is measured in Å / cycle units.)

[0207] The thin film formation method is characterized in that the intensity of residual halogen in the thin film (c / s) based on the thin film thickness at 100°C, as measured based on SIMS, is preferably 100,000 or less, more preferably 70,000 or less, even more preferably 50,000 or less, and even more preferably 10,000 or less. In a preferred embodiment, it may be 5,000 or less, more preferably 1,000 to 4,000, and even more preferably 1,000 to 3,800. Within this range, the effect of preventing corrosion and deterioration is excellent.

[0208] The purging period described herein is preferably 1,000 to 50,000 sccm (Standard Cubic Centimeter Per Minute), more preferably 2,000 to 30,000 sccm, and even more preferably 2,500 to 15,000 sccm. Within this range, the thin film growth rate per cycle is appropriately controlled, resulting in the advantage of single-atomic mono-layer deposition, or deposition close to it, which is advantageous in terms of film quality.

[0209]

[0210] The aforementioned ALD (atomic layer deposition process) is extremely advantageous in the fabrication of integrated circuits (ICs) that require a high aspect ratio, and in particular, its self-limiting thin film growth mechanism offers advantages such as excellent conformality, uniformity, and precise thickness control.

[0211] The thin film formation method may, for example, be carried out at a deposition temperature in the range of 50 to 800°C, preferably in the range of 300 to 700°C, more preferably in the range of 400 to 650°C, even more preferably in the range of 400 to 600°C, and even more preferably in the range of 450 to 600°C. Within this range, there is an effect of growing a thin film with excellent film quality while embodying the ALD process characteristics.

[0212] The thin film formation method may, for example, be carried out with a deposition pressure in the range of 0.01 to 20 Torr, preferably in the range of 0.1 to 20 Torr, more preferably in the range of 0.1 to 10 Torr, and most preferably in the range of 1 to 7 Torr. This method has the effect of obtaining a thin film of uniform thickness within this range.

[0213] In this description, the deposition temperature and deposition pressure may be measured by the temperature and pressure formed inside the deposition chamber, or by the temperature and pressure applied to the substrate inside the deposition chamber.

[0214] The thin film formation method preferably includes the step of raising the temperature inside the chamber to the deposition temperature before introducing the shielding compound into the chamber; and / or the step of injecting an inert gas into the chamber and purging it before introducing the shielding compound into the chamber.

[0215] Furthermore, the present invention may also include a thin film manufacturing apparatus capable of embodying the thin film manufacturing method, comprising an ALD chamber, a first vaporizer for vaporizing a shielding compound, a first transfer means for transferring the vaporized shielding compound into the ALD chamber, a second vaporizer for vaporizing a thin film precursor, and a second transfer means for transferring the vaporized thin film precursor into the ALD chamber. Here, the vaporizer and transfer means are not particularly limited as long as they are vaporizers and transfer means commonly used in the art to which the present invention belongs.

[0216]

[0217] As a specific example, the thin film formation method described above is first placed in a deposition chamber capable of atomic layer deposition on which a thin film can be formed on top.

[0218] The substrate may include semiconductor substrates such as silicon substrates and silicon oxide.

[0219] The substrate may have a conductive layer or an insulating layer further formed on its upper surface.

[0220] To deposit a thin film onto a substrate positioned within the deposition chamber, the aforementioned shielding compound and a precursor compound, or a mixture thereof with a nonpolar solvent, are prepared.

[0221] Subsequently, the prepared shielding compound is injected into the vaporizer, converted into a vapor phase, and transferred to the deposition chamber where it is adsorbed onto the substrate. Finally, purging is performed to remove any unadsorbed shielding compound.

[0222] Next, the prepared precursor compound, or a mixture thereof with a nonpolar solvent (thin film forming composition), is injected into the vaporizer, converted into a vapor phase, and transferred to the deposition chamber where it is adsorbed onto the substrate, and any unadsorbed precursor compound / thin film forming composition is purged.

[0223] In this description, the steps of adsorbing the shielding compound onto the substrate and then purging to remove any unadsorbed shielding compound, and adsorbing the precursor compound onto the substrate and then purging to remove any unadsorbed precursor compound, may be performed in a different order as needed.

[0224] In this description, the method for transferring the shielding compound and precursor compound (thin film formation composition) to the deposition chamber may, for example, be a method of transferring volatile gas using a mass flow controller (MFC) method (Vapor Flow Control; VFC), or a method of transferring liquid using a liquid mass flow controller (LMFC) method (Liquid Delivery System; LDS), with the LDS method being preferred.

[0225] Here, one or more mixed gases selected from the group consisting of argon (Ar), nitrogen (N2), and helium (He) may be used as the carrier gas or diluent gas for moving the shielding compound and precursor compound onto the substrate, but are not limited to these.

[0226] As an example of the purging gas described herein, an inert gas may be used, and preferably the carrier gas or diluent gas may be used.

[0227]

[0228] Next, a reaction gas is supplied. The reaction gas is not particularly limited as long as it is a reaction gas commonly used in the art to which the present invention belongs, and preferably may contain a nitride agent. The nitride agent reacts with the precursor compound adsorbed on the substrate to form a nitride film.

[0229] Preferably, the nitriding agent may be nitrogen gas (N2), hydrazine gas (N2H4), or a mixture of nitrogen gas and hydrogen gas.

[0230] Next, an inert gas is used to purge any unreacted residual reaction gas. This removes not only the excess reaction gas but also any by-products that have been generated.

[0231] As described above, the thin film formation method may, as an example, be repeated in a unit cycle to form a thin film of a desired thickness, with the unit cycle consisting of the steps of shielding a shielding compound onto a substrate, purging unadsorbed shielding compounds, adsorbing a precursor compound / thin film forming composition onto a substrate, purging unadsorbed precursor compound / thin film forming composition, supplying a reaction gas, and purging residual reaction gas.

[0232] As another example, the thin film formation method may involve a unit cycle consisting of the steps of adsorbing a precursor compound / thin film forming composition onto a substrate, purging unadsorbed precursor compound / thin film forming composition, adsorbing a shielding compound onto the substrate, purging unadsorbed shielding compound, supplying a reaction gas, and purging residual reaction gas, and repeating this unit cycle to form a thin film of a desired thickness.

[0233] The aforementioned unit cycle may be repeated, for example, 1 to 99,999 times, preferably 10 to 1,000 times, more preferably 50 to 5,000 times, and even more preferably 100 to 2,000 times, and within this range, the desired thin film characteristics are well expressed.

[0234]

[0235] The present invention also provides a semiconductor substrate, characterized in that the semiconductor substrate is manufactured by the thin film formation method described herein, and in such a case, the step coverage and thickness uniformity of the thin film are greatly improved, and the density and electrical properties of the thin film are excellent.

[0236] The manufactured thin film preferably has a thickness of 20 nm or less, a resistance value of 50 to 400 μΩ·cm relative to a thin film thickness of 10 nm, a halogen content of 10,000 ppm or less, and a step coverage rate of 90% or more. Within this range, it exhibits excellent performance as a diffusion-blocking film and has the effect of reducing corrosion of metal wiring materials, but is not limited to this.

[0237] The thin film may have a thickness of, for example, 0.1 to 20 nm, preferably 1 to 20 nm, more preferably 3 to 25 nm, and even more preferably 5 to 20 nm, and within this range, it has the effect of exhibiting excellent thin-film properties.

[0238] For example, the thin film may have a resistance value of 0.1 to 400 μΩ·cm relative to a thin film thickness of 10 nm, preferably 15 to 300 μΩ·cm, more preferably 20 to 290 μΩ·cm, and even more preferably 25 to 280 μΩ·cm, and within this range, it has the effect of exhibiting excellent thin film characteristics.

[0239] Said thin film preferably has a halogen content of 10,000 ppm or less, alternatively 1 to 9,000 ppm, more preferably 5 to 8,500 ppm, even more preferably 100 to 1,000 ppm, and within this range, there is an effect that the thin film growth rate is reduced while excellent thin film properties are maintained. Here, examples of the halogen remaining in said thin film include Cl₂, Cl, or Cl - , and the lower the residual halogen content in the thin film, the better the film quality, which is preferable.

[0240] As an example, said thin film has a step coverage of 90% or more, preferably 92% or more, more preferably 95% or more, and within this range, even a thin film with a complex structure can be easily deposited on a substrate, which has the advantage of being applicable to next-generation semiconductor devices.

[0241]

[0242] As an example, said thin film may have a two-layer or three-layer multilayer structure if necessary. As a specific example, said two-layer multilayer film may have a lower layer film-intermediate layer film structure, and as a specific example, said three-layer multilayer film may have a lower layer film-intermediate layer film-upper layer film structure.

[0243] As an example, said lower layer film may contain one or more selected from the group consisting of Si, SiO₂, MgO, Al₂O₃, CaO, ZrSiO₄, ZrO₂, HfSiO₄, Y₂O₃, HfO₂, LaLuO₂, Si₃N₄, SrO, La₂O₃, Ta₂O₅, BaO, and TiO₂.

[0244] As an example, said intermediate layer film comprises Ti x N y , preferably TiN.

[0245] As an example, said upper layer film may contain one or more selected from the group consisting of W and Mo.

[0246]

[0247] The following examples and drawings illustrate the present invention, but these examples and drawings are merely illustrative. It will be obvious to those skilled in the art that various changes and modifications are possible within the scope of the invention and the technical concept, and such variations and modifications will naturally fall within the scope of the attached claims.

[0248]

[0249] [Examples]

[0250] Examples 1 to 8, Comparative Examples 1 to 4

[0251] The ALD deposition process was carried out using the components shown in Table 1 below.

[0252] Specifically, the shielding compounds prepared were the compounds represented by chemical formulas 1-1 to 1-4, 2-1 to 2-4, 3-1, and 3-2.

[0253] [Chemical formulas 1-1 to 1-4]

[0254] [ka]

[0255] [Chemical formulas 2-1 to 2-4]

[0256] [ka]

[0257] [Chemical formulas 3-1 to 3-2]

[0258] [ka]

[0259] Further, as precursors, tris(dimethylamido)cyclopentadienyl hafnium of CpHf(NMe2)3 (denoted as CpHf in the table below), (methyl-3-cyclopentadienylpropylamino)bis(dimethylamino) hafnium of Cp(CH2)3NM3Hf(NMe2)2 (denoted as H03 in the table below), and TiCl4 were prepared respectively.

[0260] The prepared blocking compound was placed in a canister and supplied at room temperature to a vaporizer heated to 150°C at a flow rate of 0.05 g / min using an LMFC (Liquid Mass Flow Controller). After the blocking compound vaporized into the vapor phase in the vaporizer was introduced into a deposition chamber loaded with a substrate for 1 second, argon gas was supplied at 5000 sccm for 2 seconds to perform argon purging. At this time, the pressure in the reaction chamber was controlled to 2.5 Torr. Next, the prepared precursor compound was placed in a separate canister and supplied at room temperature to a separate vaporizer heated to 150°C at a flow rate of 0.05 g / min using an LMFC (Liquid Mass Flow Controller). After Si2Cl6 vaporized into the vapor phase in the vaporizer was introduced into the deposition chamber for 1 second, argon gas was supplied at 5000 sccm for 2 seconds to perform argon purging. At this time, the pressure in the reaction chamber was controlled to 2.5 Torr.

[0261] Next, 1000 sccm of ammonia or ozone as a reactive gas was introduced into the reaction chamber for 3 seconds, followed by argon purging for 3 seconds. At this time, the substrate on which the metal thin film can be formed was heated under the temperature conditions shown in Table 1 below.

[0262] Such a process was repeated 200 to 400 times to form a self-limiting atomic layer thin film with a thickness of 10 nm.

[0263] For each of the obtained thin films of Examples 1 to 8 and Comparative Examples 1 to 4, the deposition rate reduction rate (D / R reduction rate) and SIMS C impurities were measured by the method described below, and the results are shown in Table 1 below and FIGS. 1 to 2 below.

[0264] *Deposition rate reduction rate (D / R (dep.rate) reduction rate): This represents the ratio of the reduction in the deposition rate after the application of the shielding agent compared to the D / R before the application of the shielding agent, and was calculated as a percentage using the measured A / cycle values.

[0265] Specifically, the thickness of the manufactured thin film, measured using an ellipsometer (a device capable of measuring optical properties such as thickness and refractive index of a thin film using the polarization characteristics of light), was divided by the number of cycles to calculate the thickness of the thin film deposited per cycle, and the rate of decrease in the thin film growth rate was then calculated. Specifically, the calculation was performed using the following formula 1.

[0266] [Formula 1]

[0267]

number

[0268] (In the above formula, DRn is the depth rate measured in a thin film manufactured without the shielding compound, and DRw is the depth rate measured in a thin film manufactured with the shielding compound. Here, the depth rate is a value measured using an ellipsometer on thin films with a thickness of 3 to 30 nm under normal temperature and pressure conditions, and is measured in Å / cycle units.)

[0269] *SIMS (Secondary-ion mass spectrometry) C impurities: The C impurity value was confirmed using a SIMS graph, taking into account the C impurity content (counts) at a sputter time of 50 seconds, when the thin film penetrates the substrate surface layer axially by ion sputtering and contamination is minimal.

[0270] [Table 1]

[0271] As shown in Table 1 and Figures 1 to 2 below, Example 4, which used the shielding compound according to the present invention, not only showed a significant improvement in the reduction rate of deposition rate compared to Comparative Example 4, which did not use the shielding compound, but also demonstrated superior impurity reduction characteristics. Furthermore, Examples 1 to 3 and 5 to 8, which used the shielding compound according to the present invention, not only showed a significant improvement in the reduction rate of deposition rate compared to Comparative Examples 1 to 3, which used other types that deviated from the appropriate type, such as THF and CPME, but also demonstrated superior impurity reduction characteristics.

[0272] In particular, it was confirmed that Examples 1 to 8, which used the shielding compound according to the present invention, showed a reduction in the thin film growth rate per cycle of 20% or more compared to Comparative Example 4, which did not use the shielding compound, or Comparative Examples 1 to 3, which used THF and CPME.

[0273]

[0274] Additional experimental examples

[0275] Confirmation of the degree of oxidation inside a thin film

[0276] To confirm the internal state of the thin films produced in Example 8 and Comparative Example 3, the ratio of oxygen (O) to hafnium (Hf) was analyzed.

[0277] Specifically, the thin films with a thickness of approximately 10 nm produced in Example 8 and Comparative Example 3 were analyzed for Hf and O elements through XPS (X-ray Photoelectron Spectroscopy) while penetrating in the depth direction, and the elemental ratios (at%) of Hf and O elements were converted to a ratio (O / Hf ratio) and are shown in Figures 3 and 4 below.

[0278] Figure 3 below is an analysis graph of the ratio of oxygen (O) to hafnium (Hf) in the thin film produced in Comparative Example 3, and Figure 4 below is an analysis graph of the ratio of oxygen (O) to hafnium (Hf) in the thin film produced in Example 8. The longer the etch time, the deeper the oxidation state inside the HfO2 thin film.

[0279] As shown in Figure 4 below, when the deposition rate (D / R) of the blocking compound of Chemical Formula 2-1 is greatly reduced to reach 88.5%, the number of exposures to the reactant O₃ is 2 to 4 times higher than that in the conventional case, so it can be seen that sufficient oxidation is achieved.

[0280] For reference, the presence of metallic Hf may sometimes cause a problem that the dielectric constant, which is extremely important for a dielectric, decreases. The stoichiometric ratio of HfO₂ is hafnium (1): oxygen (2). Simulation results show that the O / Hf ratio before application of the blocking agent is 1.9. Reflecting this fact, when observing the intermediate point (etch time@150sec) of 5nm thickness without external influence in the depth direction of a 10nm thin film to which the compound of Chemical Formula 2-1 of Example 8 is applied as a blocking agent, it is analyzed that the thin film is further oxidized by 10% compared with that before application of the blocking agent, and the O / Hf ratio is 2.0.

[0281] On the other hand, as shown in Figure 3 below, when the blocking compound of Chemical Formula 3-2 is used to reduce the deposition rate (D / R), it can be confirmed that Hf is insufficiently oxidized compared with the conventional process without applying a blocking agent. Reflecting the aforementioned stoichiometric ratio of HfO₂ and the simulated O / Hf ratio of 1.9 before application of the blocking agent, when observing the intermediate point (etch time@200sec) of 5nm thickness without external influence in the depth direction of a 10nm thin film to which the compound of Chemical Formula 3-2 of Comparative Example 3 is applied as a blocking agent, it is analyzed that oxidation is insufficient by 3.75% compared with that before application of the CPME blocking agent, and the O / Hf ratio is 1.83.

[0282] That is, when the dotted line is relatively higher than the solid line, it can be considered closer to HfO₂.₀, and a higher value can be interpreted as more preferable. It can be seen that when the blocking compound of the present invention is applied, the degree of oxidation inside the thin film is effectively improved.

[0283]

[0284] Evaluation of step coverage and thickness uniformity

[0285] The step coating characteristics were confirmed for the thin film produced in Example 4 and the thin film produced in Example 5, respectively.

[0286] Figure 5 below shows TEM measurement images of test specimens obtained by horizontally cutting a thin film deposited on a substrate with a complex structure and an aspect ratio of 22:1 under the conditions of Example 4, at a position 100 nm below the top (left diagram) and at a position 100 nm above the bottom (right diagram).

[0287] Specifically, the deposition process was carried out using the conditions for applying the shielding agent of Example 4 to a substrate with a complex structure having an aspect ratio of 22:1, with an upper diameter of 90 nm, a lower diameter of 65 nm, and a via hole depth of approximately 2000 nm.

[0288] To confirm the uniformity of thickness and step-level coverage of the deposited material inside vertically formed via holes, test specimens were prepared by horizontally cutting them at positions 100 nm from the top downwards and 100 nm from the bottom upwards, and measurements were taken using an electron transmission microscope (TEM).

[0289] Here, the left side of Figure 5 shows a diagram where the measurement was taken at a position 100 nm from the top, and the right side of Figure 5 shows a diagram where the measurement was taken at a position 100 nm from the bottom.

[0290] In Figure 5 below, the thin base represents SiO2, and the dark black area represents HfO2. Considering the approximately 8 nm thickness deposited on the upper inner wall of the via hole and the approximately 1.5 nm thickness deposited on the lower inner wall, the step coverage was analyzed to be 18.75%.

[0291] In particular, as shown in the diagram on the right, the lack of continuity in the black lines is evident, which confirms the absence of uniformity in a narrow, deep, and complex structure.

[0292]

[0293] Figure 6 below shows TEM measurement images of test specimens horizontally cut at a position 100 nm below the top (left diagram) and a position 100 nm above the bottom (right diagram) of a thin film deposited on a substrate with a complex structure and an aspect ratio of 22:1 under the conditions for applying the shielding compound of chemical formula 1-3 in Example 5.

[0294] Specifically, the deposition process was carried out using the conditions for applying the shielding agent of Example 4 to a substrate with a complex structure having an aspect ratio of 22:1, with an upper diameter of 90 nm, a lower diameter of 65 nm, and a via hole depth of approximately 2000 nm.

[0295] To confirm the uniformity of thickness and step-level coverage of the deposited material inside vertically formed via holes, test specimens were prepared by horizontally cutting them at positions 100 nm from the top downwards and 100 nm from the bottom upwards, and measurements were taken using an electron transmission microscope (TEM).

[0296] Here, the left side of Figure 6 shows the measurement taken at a position 100 nm from the top, and the right side of Figure 6 shows the measurement taken at a position 100 nm from the bottom.

[0297] In Figure 6 below, the thin base represents SiO2, and the dark black area represents HfO2. Considering the approximately 7.7 nm thickness deposited on the upper inner wall of the via hole and the approximately 7.6 nm thickness deposited on the lower inner wall, the step coverage was analyzed to be 98.7%.

[0298] In particular, the clear continuity of the black lines in both the left and right diagrams indicates excellent uniformity in narrow, deep, and complex structures.

[0299]

[0300] As discussed above, the results of examining the step coverage rate and thickness uniformity showed that, among Example 4 using the shielding compound of chemical formula 2-1 and Example 5 using the shielding compound of chemical formula 1-3, Example 5 provided even better step coverage rate and thickness uniformity compared to Example 4.

[0301]

[0302] Thin film crystalline

[0303] XRD analysis was performed on a sample in which no shielding compound was added, as in Comparative Example 4, and on a sample in which the shielding compound was added at a rate of 0.1 g / min before the thin-film precursor compound was added, as in Example 1. The results are shown in Figure 7 below.

[0304] Figure 7 below shows the XRD crystal patterns of Comparative Example 4 (black) and Example 1 (blue).

[0305] As shown in Figure 7 below, in Example 1, when the shielding compound was added at a rate of 0.1 g / min before the thin film precursor compound was added to provide shielding, it was confirmed that the crystal grain size of the thin film increased further, i.e., the crystallinity increased.

[0306] Here, the size of the crystal grains can be determined by the width of the peak at the 31.5° position of the HfO2 thin film. A narrower peak indicates higher crystallinity, and an increase in crystallinity has the advantage of significantly improving the dielectric constant. In addition, among monoclinic and orthorhombic (tetragonal) crystal systems, the characteristic peak of tetragonal, which has the highest dielectric constant, was observed at 30.5°.

[0307]

[0308] Thin film density

[0309] X-ray reflectance (XRR) analysis was performed on samples where no shielding compound was added, as in Comparative Example 4, and on samples where the shielding compound was added at a rate of 0.1 g / min before the thin-film precursor compound was added, as in Example 4. The measurement results are shown in Table 1 below.

[0310] Furthermore, after repeating the same process as in Example 4, except that the deposition temperature was changed to 340 degrees and 420 degrees, reflectance (XRR) analysis was performed, and the measurement results are shown in items 4-1 and 4-2, respectively.

[0311] Subsequently, after repeating the same process as in Comparative Example 4, except that the deposition temperature was changed to 380 degrees and 420 degrees, reflectance (XRR) analysis was performed, and the measurement results are shown in items 4-1 and 4-2, respectively.

[0312] [Table 2]

[0313] As shown in Table 2 above, in each of Examples 4, 4-1, and 4-2, when the shielding compound was added at a rate of 0.1 g / min before the addition of the thin film precursor compound, it was confirmed that the thin film density was significantly improved compared to all of Comparative Examples 4, 4-1, and 4-2.

[0314] Therefore, according to the present invention, by providing a compound with a predetermined structure as a shielding agent, a deposition layer of uniform thickness is formed on the substrate as a shielding region due to the difference in the adsorption distribution map of the shielding agent, thereby reducing the deposition rate of the thin film and appropriately lowering the thin film growth rate. This greatly improves step coverage and the uniformity of the thin film thickness even when forming a thin film on a substrate with a complex structure, and greatly reduces impurities. The present invention also provides a shielding compound, a thin film formation method using the same, and a semiconductor substrate and semiconductor device manufactured therefrom.

Claims

1. A shielding compound characterized by being selected from one or more compounds represented by the following chemical formulas 1-1 to 1-4 and 2-1 to 2-4, wherein the shielding compound provides a shielding region for an oxide film, nitride film, or metal film, and the shielding region is formed on the entire substrate or a part of the substrate on which the oxide film, nitride film, or metal film is formed. When the total area of ​​the substrate is considered to be 100%, the shielded area occupies 10 to 95% of the total area of ​​the entire substrate or a portion of the substrate, and the unshielded area occupies the remaining area. The shielding compound has the effect of reducing, preventing, or blocking the adsorption of at least the precursor compound for forming the thin film onto the substrate, and A shielding compound characterized in that the shielding region corresponds to a region formed using the shielding compound. [Chemical formulas 1-1 to 1-4] 【Transformation 3】 [Chemical formulas 2-1 to 2-4] 【Chemistry 4】

2. The shielding compound according to claim 1, characterized in that the oxide film, nitride film, or metal film is used as a diffusion prevention film, etching stop film, electrode film, dielectric film, gate insulating film, block oxide film, or charge trap.

3. A method for forming a thin film, characterized by comprising the step of injecting the shielding compound described in claim 1 into a chamber to shield the surface of a loaded substrate.

4. The thin film forming method according to claim 3, characterized in that the chamber is an ALD chamber, a CVD chamber, a PEALD chamber, or a PECVD chamber.

5. The thin film formation method according to claim 3, characterized in that the shielding compound is transferred into the chamber by VFC, DLI, or LDS, and the thin film is a silicon nitride film, a silicon oxide film, a titanium nitride film, a titanium oxide film, a tungsten nitride film, a molybdenum nitride film, a hafnium oxide film, a zirconium oxide film, a tungsten oxide film, or an aluminum oxide film.

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