Activator, semiconductor substrate and semiconductor device manufactured using the same

Abstract

The present invention relates to an activator, and a semiconductor substrate and a semiconductor device manufactured using the same. The method for manufacturing a titanium-containing vapor-deposited film of the present invention uses a titanium-based precursor compound and a specific reaction gas, which has the effect of facilitating the production of a high-purity vapor-deposited film through a simple process.

Description

[Technical Field]

[0001] The present invention relates to an activator, and a semiconductor substrate and a semiconductor device manufactured using the same. More specifically, the present invention relates to an activator that provides a compound containing a halogen different from a halogen ligand contained in a precursor compound as an activator, and that exchanges with the halogen ligand in the precursor compound to improve reactivity with a subsequently injected reactant, thereby improving the deposition reaction rate and significantly increasing the density and resistivity of the deposited film, while also significantly reducing impurities. The present invention also relates to a semiconductor substrate and a semiconductor device manufactured using the same. [Background technology]

[0002] An ideal atomic layer deposition (ALD) process is based on a self-limiting reaction, where ligands of a precursor adsorbed on the substrate prevent subsequent implantation of the precursor. However, in actual processes, the precursor may undergo thermal decomposition, in which ligands desorb from the metal center. This process is a type of chemical vapor deposition (CVD), and the greater this decomposition, the lower the step coverage, density, and thickness uniformity of the deposited film. Furthermore, if the desorbed ligand species successfully adsorb on the surface as F or Cl, or successfully form fluorides or chlorides, they can remain as impurities in the deposited thin film. (See J. Phys. Chem. B. 13491-8, "Surface chemistry in the atomic layer deposition of TiN films from TiCl4 and ammonia" (2006))

[0003] The density and thickness uniformity of the deposited film are factors that affect the electrical and chemical properties. For example, electrical conductivity may be reduced, and by-products (e.g., HCl) derived from the leaving groups of the halogen ligands may be absorbed to contaminate the deposited film or disrupt the crystalline arrangement of the deposited film, further reducing the density.

[0004] Therefore, it is important to minimize the thermal history of the precursor so that the process can occur within the atomic layer deposition (ALD) window. However, typically, the higher the deposition temperature, the better the film quality. For example, when depositing titanium nitride thin films, films deposited at higher temperatures exhibit lower resistivity. To achieve low resistivity thin films even at lower deposition temperatures, a self-limiting reaction can be achieved by exchanging the first ligand of the precursor adsorbed on the substrate with a more reactive second ligand, which then reacts with the reactant to form a deposited film with a complex structure. This not only improves the thickness uniformity and deposition reaction rate of the deposited film, but also reduces the amount of residual impurities, significantly improves density, and even improves electrical properties such as resistivity. Therefore, there is a need for a method for manufacturing deposited films using this second ligand, as well as semiconductor substrates and semiconductor devices manufactured using this second ligand. Summary of the Invention [Problem to be solved by the invention]

[0005] In order to solve the above-mentioned problems of the conventional technology, the present invention aims to provide an activator that provides a compound having a predetermined structure as a second ligand to replace the first ligand of a precursor compound, thereby significantly improving the deposition reaction rate, thickness uniformity and density of the deposited film, and even improving electrical properties, and a semiconductor substrate and a semiconductor device manufactured using the same.

[0006] The above and other objects of the present invention can all be achieved by the present invention described below. [Means for solving the problem]

[0007] To achieve the above object, the present invention provides an activator containing an alkyl-free halide for exchanging the ligands of a precursor compound bound to a Group 4 metal center.

[0008] The present invention also provides an activator comprising an alkyl-free halide for burying the ligand leaving site of the precursor compound bound to the Group 4 metal center.

[0009] When the precursor compound contains a halogen, if the halogen is defined as a first halogen, the halogen constituting the alkyl-free halide may be a second halogen different from the first halogen.

[0010] The first halogen may be one or more selected from fluorine, chlorine, iodine and bromine.

[0011] The second halogen may be one or more selected from iodine and bromine.

[0012] The alkyl-free halide may form an intermediate to provide a deposited film having reactant-derived material bound to the Group 4 metal.

[0013] The reactant-derived substances can be provided by H2O, H2O2, O2, O3, O radicals, D2, H2, H radicals, NH3, NO2, N2O, N2, N radicals, H2S or S.

[0014] The intermediate may refer to a state in which a compound of defined structure is provided as a second ligand to replace the first ligand of a precursor compound.

[0015]

[0016] The Group 4 metal center can be titanium.

[0017] The alkyl-free halide can be an alkyl-free iodine donor, hydrogen iodide gas, hydrogen bromide gas, iodine ions, or iodine radicals.

[0018] The deposition can be atomic layer deposition (ALD), plasma-enhanced atomic layer deposition (PEALD), vapor deposition (CVD), plasma-enhanced vapor deposition (PECVD), metal-organic chemical vapor deposition (MOCVD), or low-pressure vapor deposition (LPCVD).

[0019]

[0020] Furthermore, the present invention provides a semiconductor substrate in which, when the adsorption state of the precursor on the substrate before ligand exchange is -M-Xn (n=1 to 3, X=F, Cl), the adsorption state of the precursor after ligand exchange is -M-Ym (m=1 to 3, Y=Br, I).

[0021] The change in the state of precursor adsorption before and after the ligand exchange can be formed by the reaction of a precursor compound having a first halogen bonded to a Group 4 central metal on the substrate with an alkyl-free halide containing a second halogen to fill the ligand leaving site of the precursor compound.

[0022] The semiconductor substrate may include a deposition film formed through a process in which a first halogen atom (F or Cl) in the central metal (M) of Chemical Formula 1 above is replaced with a second halogen atom (Br or I).

[0023]

[0024] The deposited film may include a structure represented by the following Chemical Formula 2:

[0025] [Chemical formula 2]

[0026] [ka]

[0027] (In the above chemical formula 1, M is a Group 4 metal, H is one or more of O, N, and S, a is an integer of 1, and d is 0 to 2.2.)

[0028] The composition of the deposited film can be confirmed by analysis using X-ray photoelectron spectroscopy (XPS).

[0029] The deposited film may have a multilayer structure of two or more layers, a multilayer structure of three or more layers, or a multilayer structure of two or three layers.

[0030] The deposited film may have a deposition thickness of 500 Å or less as measured by an ellipsometer.

[0031] The vapor-deposited film may have a resistivity of 300 μΩ·cm or less.

[0032] The density of the vapor-deposited film is 4.5 g / cm 3 It could be more than that.

[0033] The deposited film may have 50 or more iodine atom counts / second (counts / s) as measured by secondary ion mass spectrometry (SIMS).

[0034] The deposited film may be an oxide film, a nitride film, a metal film, or a sulfide film, and may be used as a diffusion barrier film, an etching stop film, an electrode film, a dielectric film, a gate insulating film, a block oxide film, or a charge trap.

[0035]

[0036] Furthermore, the present invention provides a semiconductor device including the semiconductor substrate described above. [Effects of the Invention]

[0037] According to the present invention, the leaving group of the precursor adsorbed on the substrate is exchanged with a second halogen, thereby improving the deposition reaction rate and providing an activation effect that appropriately increases the thickness uniformity and density of the deposited film, thereby improving the productivity of the deposited film.

[0038] Furthermore, when forming a deposited film, the density is improved and process by-products are more effectively reduced, preventing corrosion and deterioration. Furthermore, the crystallinity of the deposited film is improved, thereby improving the electrical properties of the deposited film.

[0039] Furthermore, the thickness uniformity of the deposited film can be improved, and further, there are effects of providing a method for producing a deposited film using this, and a semiconductor substrate and a semiconductor device produced thereby. [Brief explanation of the drawings]

[0040] [Figure 1] FIG. 1 is a graph comparing the deposition thickness and resistivity measured for eight types of deposited films from Example 1, in which an activator was used according to the present invention, and ten types of deposited films from Comparative Example 1, in which no activator was used.

[0041] [Figure 2] FIG. 1 is a diagram comparing the contents of process by-products and impurities (Cl, O, Si, H, NH, metals, and metal oxides) measured by SIMS in Comparative Example 1, in which no activator was used.

[0042] [Figure 3] FIG. 1 is a diagram comparing the contents of process by-products and impurities (Cl, O, Si, H, NH, metals, and metal oxides) measured by SIMS in Example 1, in which an activator was used according to the present invention.

[0043] DETAILED DESCRIPTION OF THE INVENTION

[0044] The activator described above, and the semiconductor substrate and semiconductor device produced using the same will be described in detail below.

[0045] The present inventors have discovered that by providing a specific compound as an activator capable of replacing ligands released from a precursor compound used to form a deposited film on the surface of a substrate loaded into a chamber, the deposition reaction rate can be improved, the density and resistivity of the deposited film can be significantly improved while ensuring the thickness uniformity of the deposited film, and residual process by-products such as Cl, O, Si, H, NH, metals, and metal oxides can be reduced. Based on this discovery, the inventors have incorporated their research into activators and have completed the present invention.

[0046]

[0047] The activator, the semiconductor substrate including the deposited film manufactured using the same, and the semiconductor device will be described in detail below.

[0048]

[0049] activator

[0050] The activator is a deposition additive compound used in the present invention to more effectively form a deposition film on the surface of a substrate loaded into the chamber, and may be a predetermined compound capable of exchanging the ligand to be released.

[0051] For example, the precursor compound may be a compound in which a halogen is bonded to a Group 4 central metal, and therefore, during injection into a substrate to form a deposited film, a considerable number of the halogens are released to form ligand leaving sites.

[0052] When the activating agent used in the present invention is an alkyl-free halide, it can adequately fill the ligand elimination site.

[0053] The term "alkyl free" refers not only to those that do not contain alkyl groups, but also to those that do not contain alkene or alkyne groups, unless otherwise specified.

[0054] When the halogen constituting the precursor compound is a first halogen, the halogen constituting the alkyl-free halide may be a second halogen different from the first halogen.

[0055] The first halogen may be one or more selected from fluorine, chlorine, iodine and bromine.

[0056] The second halogen may be one or more selected from iodine and bromine.

[0057] The activator may preferably be a compound with a purity of 99.9% or more, a compound with a purity of 99.95% or more, or a compound with a purity of 99.99% or more. For reference, if a compound with a purity of less than 99% is used, impurities may remain in the deposited film or may cause side reactions with the precursor or reactant, so it is best to use a substance with a purity of 99% or more whenever possible.

[0058]

[0059] The activator preferably has a density of 1.0 to 4.0 g / cm 3 or 2.0 to 3.4 g / cm 3 The vapor pressure can be 1 atmosphere at 180 to 240K, and within this range, there is an outstanding effect of improving step coverage, thickness uniformity of the deposited film, resistivity, and film quality.

[0060] The alkyl-free halide can form an intermediate for providing a deposited film having a structure in which a reactant-derived substance is bonded to the Group 4 metal.

[0061] Here, the reactant-derived substances can be provided by H2O, H2O2, O2, O3, O radical, D2, H2, H radical, NH3, NO2, N2O, N2, N radical, H2S or S.

[0062]

[0063] The alkyl-free halide is at least one selected from the group consisting of an alkyl-free iodine donor, hydrogen iodide gas, hydrogen bromide gas, iodine ions, and iodine radicals. In this case, the alkyl-free halide suppresses side reactions, adjusts the growth rate of the deposited film, reduces process by-products in the deposited film, thereby reducing corrosion and deterioration, improves the crystallinity of the deposited film, and allows a stoichiometric oxidation state to be reached during the formation of a metal oxide film. This significantly improves step coverage and thickness uniformity of the deposited film, even when the deposited film is formed on a substrate with a complex structure.

[0064] Specifically, the activator may be 3N to 15N hydrogen iodide alone, a gas mixture of 1 to 99% by weight of 3N to 15N hydrogen iodide with the balance of an inert gas to bring the total to 100% by weight, or an aqueous solution mixture of 0.5 to 70% by weight of 3N to 15N hydrogen iodide with the balance of water to bring the total to 100% by weight. When the inert gas is nitrogen, helium, or argon with a purity of 4N to 9N, the inert gas is highly effective in reducing process by-products and has excellent step coverage, as well as excellent effects in improving the density and electrical properties of the deposited film.

[0065] Preferably, the activator is 3N to 7N hydrogen iodide alone, a gas mixture of 5N to 6N hydrogen iodide at 1 to 99% by weight with the remainder of an inert gas to bring the total to 100% by weight, or an aqueous solution mixture of 5N to 6N hydrogen iodide at 0.5 to 70% by weight with the remainder of water to bring the total to 100% by weight, where the inert gas may be nitrogen, helium, or argon with a purity of 4N to 9N. In this case, during the formation of a deposited film, substitution regions that do not remain in the deposited film are formed, resulting in a relatively coarse deposited film, while suppressing side reactions and adjusting the growth rate of the deposited film, thereby reducing process by-products in the deposited film and reducing corrosion and degradation, improving the crystallinity of the deposited film, and significantly improving step coverage and thickness uniformity of the deposited film even when the deposited film is formed on a substrate with a complex structure.

[0066] In the present invention, the activator or precursor compound may be vaporized and injected, followed by a plasma post-treatment, which can improve the growth rate of the deposited film while reducing process by-products.

[0067] The deposition can be atomic layer deposition (ALD), plasma-enhanced atomic layer deposition (PEALD), vapor deposition (CVD), plasma-enhanced vapor deposition (PECVD), metal-organic chemical vapor deposition (MOCVD), or low-pressure vapor deposition (LPCVD).

[0068]

[0069] precursor compound

[0070] The precursor compound used to form the vapor-deposited film in the present invention is a molecule having a Group 4 metal as the central metal atom (M) and one or more ligands consisting of C, N, O, H, and X (halogen), and when the precursor has a vapor pressure of 1 mTorr to 100 Torr at 25°C, the effect of filling leaving sites with an activator described below can be maximized.

[0071] As an example of the precursor compound, a compound represented by the following Chemical Formula 1 can be used.

[0072] [Chemical formula 1]

[0073] [ka]

[0074] (In the above formula 1, M is a quaternary metal, and L 1 , L 2 , L 3 and L 4 is -H, -X, -R, -OR, or -NR 2and each of the -X groups is the same or different from the others, and contains at least one -X group, where -X is F, Cl, or Br, and -R is C1 to C 10 Alkyl, C1-C 10 Alkenes, or C1-C 10 and may be linear or cyclic.

[0075] In the above Chemical Formula 1, M is titanium (Ti), which has the advantages of significantly reducing process by-products, providing excellent step coverage, significantly improving the density of the deposited film, and providing excellent electrical and insulating properties of the deposited film.

[0076] In the above formula 1, L 1 , L 2 , L 3 and L 4 is -H, or -X, which may be the same or different from each other, and contains at least one or more -X, where -X can be F, Cl, or Br.

[0077] In addition, for example, the titanium precursor compound may have a structure represented by the following chemical formula 1-1 or a structure represented by the following chemical formula 1-2.

[0078] [Chemical formula 1-1]

[0079] [ka]

[0080] The L1 can be H, F, Cl, Br, Me, Et, iPr, OMe, OEt, NMe2, NEt2, or NMeEt.

[0081] The L2 can be H, F, Cl, Br, Me, Et, iPr, OMe, OEt, NMe2, NEt2, or NMeEt.

[0082] The L3 can be H, F, Cl, Br, Me, Et, iPr, OMe, OEt, NMe2, NEt2, or NMeEt.

[0083] L4 can be H, F, Cl, Br, Me, Et, iPr, OMe, OEt, NMe2, NEt2, or NMeEt.

[0084] The L1 to L4 may be the same or different.

[0085] In this description, unless otherwise specified, Me represents a methyl group and Et represents an ethyl group.

[0086] The structure represented by the above chemical formula 1-1 may be, for example, TiCl4, TiBr4, Ti(OMe)4, or Ti(NMe2)4.

[0087] [Chemical formula 1-2]

[0088] [ka]

[0089] The L', L'', and L''' may be, independently of one another, OMe, OEt, NMe2, NEt2, or NMeEt.

[0090] The R can be Me or Et.

[0091] n can be an integer from 0 to 5.

[0092] Examples of the compound represented by the above chemical formula 1-2 include CpMeTi(OMe)3, CpMe2Ti(OMe)3, CpMe3Ti(OMe)3, CpMe4Ti(OMe)3, CpMe5Ti(OMe)3, CpMeTi(OEt)3, CpMe2Ti(OEt)3, CpMe3Ti(OEt)3, CpMe4Ti(OEt)3, CpMe5Ti(OEt)3, CpMeTi(NMe2)3, CpMe2Ti(NMe2)3, CpMe3Ti (NMe2)3, CpMe4Ti(NMe2)3, CpMe5Ti(NMe2)3, CpMeTi(NEt2)3, CpMe2Ti(NEt2)3, CpMe3Ti(NEt2)3, CpMe4Ti(NEt2)3, CpMe5Ti(NEt2)3, CpMeTi(NMeEt)3, CpMe2Ti(NMeEt)3, CpMe3Ti(NMeEt)3, CpMe4Ti(NMeEt)3, or CpMe5Ti(NMeEt)3.

[0093]

[0094] In the present invention, the precursor compound may be mixed with a non-polar solvent and then introduced into the chamber, which has the advantage that the viscosity and vapor pressure of the precursor compound can be easily adjusted.

[0095] The non-polar solvent may preferably be at least one selected from the group consisting of alkanes and cycloalkanes. In this case, the non-polar solvent has the advantage of containing an organic solvent that has low reactivity and solubility and allows easy moisture control, while improving step coverage even when the deposition temperature is elevated during deposition film formation.

[0096] In a more preferred example, the non-polar solvent is a C1 to C 10 Alkanes of C3 to C 10 The cycloalkanes may include cycloalkanes of the formula C3 to C6. 10 In this case, the advantage is that the reactivity and solubility are low, and moisture can be easily controlled.

[0097] In this description, C1, C3, etc. refer to the number of carbon atoms.

[0098] The cycloalkane is preferably a C3 to C 10 Among the monocycloalkanes, cyclopentane is liquid at room temperature and has the highest vapor pressure, so it is suitable for the vapor deposition process, but is not limited thereto.

[0099] The non-polar solvent has, for example, a solubility in water (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, the non-polar solvent has the advantage of low reactivity with the precursor compound and easy water management.

[0100] In this description, the solubility is not particularly limited to the measurement methods and standards commonly used in the technical field to which the present invention pertains, and as an example, a saturated solution can be measured by high performance liquid chromatography (HPLC).

[0101] The non-polar solvent preferably comprises 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, based on the total weight of the precursor compound and the non-polar solvent.

[0102] If the content of the non-polar solvent exceeds the upper limit, impurities are generated, increasing the resistance and the number of impurities in the deposited film. On the other hand, if the content of the organic solvent is less than the lower limit, the effect of improving step coverage and reducing impurities such as chlorine (Cl) ions by adding the solvent is not very good.

[0103]

[0104] Vapor-deposited film

[0105] This includes vapor-deposited films obtained using the aforementioned activators.

[0106] The deposited film may have a multi-layer structure of two or more layers.

[0107] For example, the deposited film may include a structure in which a reactant-derived substance and a second halogen are bonded to a Group 4 metal.

[0108] The deposited film may have a deposition thickness of 170 Å or less, or 100 to 170 Å, as measured by SIMS.

[0109] The resistivity of the deposited film may be 300 μΩ·cm or less, or 150 to 300 μΩ·cm, and within this range, the electrical conductivity can be improved.

[0110] The deposition rate of the deposited film may be 0.34 Å / cycle or more, or 0.34 to 0.535 Å / cycle.

[0111] The density of the vapor-deposited film was 4.8 g / cm 3 or more, or 4.8 to 5.3 g / cm 3 It could be.

[0112]

[0113] The deposition film may have an increase in deposition rate, expressed by the following Equation 1, of 10% or more, specifically 12.5% ​​or more, preferably 15% or more. In this case, the deposition film is formed using an activator having the above structure, and the growth rate of the deposited film is significantly reduced. Therefore, even when applied to a substrate with a complex structure, the uniformity of the deposited film is ensured and the step coverage is significantly improved. In particular, the deposition film can be thinly deposited, and the amounts of O, Si, metals, metal oxides, and even carbon, which are residual process by-products and have been difficult to reduce, can be reduced.

[0114] [Formula 1]

[0115] Deposition rate increase rate = [(DR f ) / (DR i )] × 100

[0116] (In the above formula, DR (Deposition rate, Å / cycle) is the rate at which the deposited film is deposited. When a deposited film is formed from a precursor and a reactant, DR i (initial deposition rate) is the deposition rate of the deposited film formed without adding an activator. f (Final Deposition Rate) is the deposition rate of the deposited film formed while adding an activator during the above process. Here, the deposition rate (DR) is the value measured at room temperature and pressure using an ellipsometer to deposit a film with a thickness of 1 to 30 nm, and is expressed in Å / cycle units.)

[0117] In Equation 1, the growth rate of the deposited film per cycle when an activator is used and when an activator is not used means the deposition thickness (Å / cycle) of the deposited film per cycle, i.e., the deposition rate. For example, the deposition rate can be calculated by measuring the final thickness of a deposited film having a thickness of 1 to 30 nm under room temperature and pressure conditions by ellipsometry, and then dividing the measured thickness by the total number of cycles to obtain an average deposition rate.

[0118] In the above formula 1, "when no activator was used" means that a deposited film is produced by adsorbing only a precursor compound onto a substrate in the deposition process of the deposited film. Specifically, this means that a deposited film is formed by omitting the step of adsorbing an activator and the step of purging unadsorbed activator in the method for forming the deposited film.

[0119] The deposited film may be a metal film, an oxide film, a nitride film, a sulfide film, or a chalcogenide film, and in this case, the effects to be achieved in the present invention can be sufficiently obtained.

[0120] The deposited film may contain the above-mentioned film composition alone or in a selective area, but the present invention is not limited thereto and is meant to encompass SiH and SiOH.

[0121] The deposited film can be used in semiconductor devices not only as a commonly used diffusion barrier film, but also as an etching stop film, an electrode film, a dielectric film, a gate insulating film, a blocking oxide film, or a charge trap.

[0122] For example, the vapor-deposited film may contain halogen compounds at a concentration of 10,500 counts / s or less as measured by SIMS.

[0123]

[0124] Method for producing vapor-deposited film

[0125] The deposited film can be produced by a variety of methods, and for example, it can be produced by the following method:

[0126] In a first step, a precursor compound containing a Group 4 metal and a first halogen may be injected onto a substrate placed in a chamber.

[0127] The first halogen may be, for example, one or more selected from the group consisting of fluorine, chlorine, iodine, and bromine, and preferably includes chlorine, which has excellent reactivity.

[0128] In this description, examples of methods that can be used to distribute the precursor compound throughout the deposition chamber include a method of transporting a vaporized gas using a gas phase mass flow controller (MFC) (Vapor Flow Control; VFC, vapor flow control), a mass flow controller method (MFC) including a liquid phase mass flow controller (LMFC), and a method of transporting a liquid (Liquid Delivery System; LDS, liquid supply system).

[0129] In this case, the carrier gas or dilution gas for transporting the precursor compound onto the substrate may be one or a mixture of two or more gases selected from the group consisting of argon (Ar), nitrogen (N), and helium (He), but the present invention is not limited thereto.

[0130] In this description, the purge gas may be, for example, an inert gas, and preferably the carrier gas or dilution gas.

[0131] The chamber can be an atomic layer deposition (ALD) chamber, a plasma-enhanced atomic layer deposition (PEALD) chamber, a vapor deposition (CVD) chamber, a plasma-enhanced vapor deposition (PECVD) chamber, a metalorganic chemical vapor deposition (MOCVD) chamber, or a low-pressure vapor deposition (LPCVD) chamber.

[0132] The substrate loaded into the chamber may include a semiconductor substrate such as a silicon substrate or silicon oxide substrate.

[0133] The substrate may further have a conductive layer or an insulating layer formed thereon.

[0134] The substrate may be maintained at a temperature of 50 to 500°C, or 80 to 500°C.

[0135] The substrate may be heated to, for example, 50 to 500°C, specifically, 80 to 500°C, 100 to 800°C, or 200 to 500°C, and the activator or precursor compound may be injected onto the substrate in an unheated or heated state. Depending on the deposition efficiency, the activator or precursor compound may be injected unheated and then the heating conditions may be adjusted during the deposition process. For example, the activator or precursor compound may be injected onto a substrate heated to 300 to 600°C for 1 to 20 seconds.

[0136] The amount (mg / cycle) of the precursor compound introduced into the chamber is, for example, 1:1 to 1:20, preferably 1:1 to 1:15, and more preferably 1:1 to 1:10, in terms of the ratio of the amount (mg / cycle) of the activator used in the second step described below to the amount (mg / cycle) of the precursor compound introduced into the chamber. Within this range, the effect of improving step coverage and the effect of reducing process by-products are outstanding.

[0137]

[0138] The first step may include one or more purging steps with an inert gas, which may be the carrier gas or diluent gas described above.

[0139] The amount of purge gas introduced into the chamber in the step of purging the unadsorbed precursor compound is not particularly limited as long as it is an amount sufficient to remove the unadsorbed precursor compound, but for example, it may be 10 to 100,000 times, preferably 50 to 50,000 times, and more preferably 100 to 10,000 times the volume of the precursor compound introduced into the chamber. Within this range, the unadsorbed precursor compound can be sufficiently removed to form a uniform deposited film and prevent deterioration of film quality. Here, the amounts of purge gas and precursor compound introduced are each based on one cycle, and the volume of the precursor compound refers to the volume of vaporized precursor compound vapor.

[0140] In this description, the purge flow rate is preferably 1,000 to 50,000 sccm (standard cubic centimeters per minute), more preferably 2,000 to 30,000 sccm, and even more preferably 2,500 to 15,000 sccm. Within this range, the growth rate of the deposited film per cycle is appropriately controlled, and deposition is performed as or close to an atomic monolayer, which is advantageous in terms of film quality.

[0141]

[0142] In the second step, an alkyl-free halide containing a second halogen different from the first halogen is injected into the substrate to exchange the leaving site of the first halogen with the second halogen. In this case, the leaving group of the precursor adsorbed on the substrate is effectively exchanged to improve the reaction rate, and the growth rate of the deposited film is appropriately reduced, resulting in significant improvements in step coverage, resistivity, and thickness uniformity of the deposited film, even when the deposited film is formed on a substrate with a complex structure.

[0143] The second halogen may be, for example, one or more selected from iodine and bromine, and it is preferable to use iodine.

[0144] The feeding time (seconds) for supplying the activator to the surface of the substrate is preferably 0.001 to 10 seconds per cycle, more preferably 0.02 to 3 seconds, even more preferably 0.04 to 2 seconds, and most preferably 0.05 to 1 second. Within this range, the deposition film has the advantages of a high growth rate, excellent step coverage, and high economy.

[0145] In this description, the activator feeding time is based on a flow rate of 1 to 500 sccm in a chamber volume of 15 to 20 L, more specifically, a flow rate of 10 to 200 sccm in a chamber volume of 18 L.

[0146] In this description, as a method for distributing the activator throughout the deposition chamber, for example, a method for transporting vaporized gas using a gas phase mass flow controller (MFC) (Vapor Flow Control; VFC) can be used.

[0147] The second step may include one or more purging steps using an inert gas, which may be, for example, the carrier gas or diluent gas.

[0148] In this description, the purge flow rate is preferably 1,000 to 50,000 sccm (Standard Cubic Centimeters per Minute), more preferably 2,000 to 30,000 sccm, and even more preferably 2,500 to 15,000 sccm. Within this range, the growth rate of the deposited film per cycle is appropriately controlled, and deposition is performed as or close to an atomic monolayer, which is advantageous in terms of film quality.

[0149] The amount of purge gas introduced into the chamber in the step of purging the unadsorbed activator is not particularly limited as long as it is an amount sufficient to remove the unadsorbed activator, but may be, for example, 10 to 100,000 times, preferably 50 to 50,000 times, and more preferably 100 to 10,000 times. Within this range, the unadsorbed activator can be sufficiently removed to form a uniform deposited film and prevent deterioration of film quality. Here, the amounts of purge gas and activator introduced are each based on one cycle, and the volume of activator refers to the volume of evaporated activator vapor.

[0150] As a specific example, in the step of injecting (per cycle) the activator at a flow rate of 100 sccm and for an injection time of 0.5 seconds, and purging the unadsorbed activator, when a purge gas is injected (per cycle) at a flow rate of 3000 sccm and for an injection time of 5 seconds, the amount of purge gas injected is 300 times the amount of activator injected.

[0151]

[0152] Then, in a third step, a reactant may be injected into the substrate to form a deposited film derived from a Group 4 metal.

[0153] The reactant may be, for example, H2O, H2O2, O2, O3, O radicals, D2, H2, H radicals, NH3, NO2, N2O, N2, N radicals, H2S, or an S-containing gas.

[0154] The deposited film may include a structure in which a reactant-derived substance and a second halogen are bonded to a Group 4 metal.

[0155] The method for forming the vapor-deposited film may be carried out at a deposition temperature in the range of, for example, 50 to 800°C, preferably 100 to 700°C, more preferably 200 to 650°C, and even more preferably 220 to 500°C. Within this range, it is possible to achieve process characteristics while growing a vapor-deposited film with excellent film quality.

[0156] The method for forming the vapor-deposited film can be carried out, for example, at a vapor deposition pressure in the range of 0.01 to 20 Torr, preferably at a vapor deposition pressure in the range of 0.1 to 20 Torr, more preferably at a vapor deposition pressure in the range of 0.1 to 10 Torr, and most preferably at a vapor deposition pressure in the range of 0.3 to 7 Torr. Within this range, there is an effect that a vapor-deposited film with a uniform thickness can be obtained.

[0157] In this description, the deposition temperature and deposition pressure may be measured as the temperature and pressure formed in the deposition chamber, or may be measured as the temperature and pressure applied to the substrate in the deposition chamber.

[0158] The second step may preferably further include a step of raising the temperature in the chamber to a deposition temperature before introducing the activator into the chamber, and / or a step of injecting an inert gas into the chamber to purge the chamber before introducing the activator into the chamber.

[0159] The third step may include a purging step with an inert gas.

[0160] Furthermore, in the purge step performed immediately after the reaction gas supply step, the amount of purge gas introduced into the chamber may be, for example, 10 to 10,000 times, preferably 50 to 50,000 times, and more preferably 100 to 10,000 times the volume of the reaction gas introduced into the chamber, and within this range, the desired effect can be sufficiently obtained. Here, the amounts of the purge gas and reaction gas introduced are each based on one cycle.

[0161] In this description, the purge flow rate is preferably 1,000 to 50,000 sccm (Standard Cubic Centimeters per Minute), more preferably 2,000 to 30,000 sccm, and even more preferably 2,500 to 15,000 sccm. Within this range, the growth rate of the deposited film per cycle is appropriately controlled, and deposition is performed as or close to an atomic monolayer, which is advantageous in terms of film quality.

[0162]

[0163] The method for forming the vapor-deposited film can be carried out by repeating a unit cycle 1 to 99,999 times as necessary, preferably 10 to 10,000 times, more preferably 50 to 5,000 times, and even more preferably 100 to 2,000 times. Within these ranges, the desired vapor-deposited film thickness can be obtained, while the effects to be achieved in the present invention can be sufficiently obtained.

[0164]

[0165] In a specific example of the method for producing the deposition film, the above-mentioned activator and a precursor compound or a mixture thereof with a non-polar solvent are prepared to deposit a deposition film on a substrate placed in the deposition chamber.

[0166] Then, the precursor compound or a mixture of the precursor compound and a non-polar solvent is injected into an evaporator, converted into a vapor phase, and spread throughout the deposition chamber to be adsorbed onto the substrate. The ligands of the precursor compound are replaced by the activator that was previously injected, while the unadsorbed precursor compound is purged.

[0167] Next, the prepared activator is injected into an evaporator, transformed into a vapor phase, and spread throughout the deposition chamber to be adsorbed onto the substrate, followed by purging to remove any unadsorbed activator.

[0168] In this description, examples of a method for distributing the activator, precursor compound, and the like throughout the deposition chamber include a method for delivering a vaporized gas using a gas phase mass flow controller (MFC) (Vapor Flow Control; VFC) and a method for delivering a liquid using a liquid phase mass flow controller (Liquid Mass Flow Controller; LMFC) (Liquid Delivery System; LDS).

[0169] In this case, the carrier gas or dilution gas for transporting the activator and precursor compound onto the substrate may be one or a mixture of two or more gases selected from the group consisting of argon (Ar), nitrogen (N), and helium (He), but is not limited thereto.

[0170] In this description, the purge gas may be, for example, an inert gas, and preferably the carrier gas or dilution gas.

[0171] Next, a reactant is supplied. The reactant may be any reaction gas commonly used in the art, but is not limited thereto. Preferably, the reactant may include a nitriding agent. The nitriding agent reacts with the precursor compound adsorbed on the substrate to form a nitride film.

[0172] Preferably, the nitriding agent may be nitrogen gas (N2), hydrazine gas (N2H4), or a mixture of nitrogen gas and hydrogen gas.

[0173] Next, an inert gas is used to purge the unreacted residual reactants. Thereby, not only the excess reactants but also the generated by-products can be removed together.

[0174] As described above, as an example, the method for forming the vapor deposition film includes steps of adsorbing a precursor compound onto a substrate, purging the unadsorbed precursor compound, supplying an activator onto the substrate, purging the unadsorbed activator, supplying a reaction gas, and purging the residual reaction gas, which are used as a unit cycle, and the unit cycle can be repeatedly performed to form a vapor deposition film with a desired film thickness.

[0175] The unit cycle can 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. Within this range, there is an effect that the characteristics of the target vapor deposition film are well exhibited.

[0176]

[0177] When the injection time and purge time of the precursor compound in the first and second steps are a and b respectively, the injection time and purge time of the alkyl-free halide in the second step are c and d respectively, and the injection time and purge time of the reactant in the third step are e and f respectively, 0.1≦a≦10, 2a≦b≦4a, 0.1<c≦10, 2c≦d≦8c, 2<e≦10, 2e≦b≦8e can be simultaneously satisfied.

[0178] When the injection and purging of the precursor compound and alkyl-free halide, and the injection and purging of the reactant constitute one cycle, the following four conditions are met: 1) the deposition thickness of the deposited film measured by an ellipsometer is 500 Å or less, 2) the resistivity of the deposited film is 300 μΩ cm or less, 3) the deposition rate is 0.34 Å / cycle or more, and 4) the density of the deposited film is 4.5 g / cm. 3 Any of the above may be satisfied.

[0179] The thickness of the deposited film measured by an ellipsometer may be 500 Å or less, or may be 2 to 300 Å, and more preferably 5 to 250 Å.

[0180] The vapor-deposited film may have a resistivity of 300 μΩ·cm or less, or 10 to 300 μΩ·cm, and more preferably 30 to 200 μΩ·cm.

[0181] The density of the vapor-deposited film is 4.5 g / cm 3 or more, or 4.5 to 5.5 g / cm 3 It could be.

[0182] The vapor-deposited film may have an iodine atom concentration of 50 counts / s or more as measured by SIMS.

[0183]

[0184] When injection and purging of the precursor compound and alkyl-free halide, and injection and purging of the reactant constitute one cycle, the deposition conditions are as follows: 1) the deposition thickness of the deposited film measured by an ellipsometer is 100 to 500 Å, 2) the resistivity of the deposited film is 150 to 300 μΩ cm, 3) the deposition rate is 0.34 to 0.535 Å / cycle, and 4) the density of the deposited film is 4.8 to 5.5 g / cm. 3 The above can be satisfied.

[0185] The method for producing a vapor-deposited film may be performed, for example, using a vapor-deposited film production apparatus including an ALD chamber, a first evaporator for vaporizing an activator, a first transport means for transporting the vaporized activator into the ALD chamber, a second evaporator for vaporizing a vapor-deposited film precursor, and a second transport means for transporting the vaporized vapor-deposited film precursor into the ALD chamber. Here, the evaporator and transport means are not particularly limited as long as they are evaporators and transport means commonly used in the technical field to which the present invention pertains.

[0186]

[0187] semiconductor substrate

[0188] The present invention also provides a semiconductor substrate, which is manufactured by the method for forming a deposited film described above or includes the deposited film described above. In such cases, the deposited film has significantly excellent step coverage and thickness uniformity, and also has excellent density and electrical properties.

[0189] As a specific example, the semiconductor substrate according to this description can provide a semiconductor substrate in which, when the adsorption state of the precursor on the substrate before the ligand exchange is -M-Xn (n=1 to 3, X=F, Cl), the adsorption state of the precursor after the ligand exchange is -M-Ym (m=1 to 3, Y=Br, I).

[0190] The change in the adsorption state of the precursor before and after the ligand exchange can be formed by the reaction of a precursor compound having a first halogen bonded to a Group 4 central metal on the substrate with an alkyl-free halide containing a second halogen to fill the ligand leaving site of the precursor compound.

[0191] For example, the semiconductor substrate may include a deposition film formed through a process in which a first halogen atom (F or Cl) in the central metal (M) of Chemical Formula 1 above is replaced with a second halogen atom (Br or I).

[0192]

[0193] For example, the deposited film may have a multilayer structure of two or more layers, a multilayer structure of three or more layers, or a multilayer structure of two or three layers, as required. A two-layer multilayer film may have a bottom layer-middle layer structure, and a three-layer multilayer film may have a bottom layer-middle layer-top layer structure.

[0194] The vapor-deposited film may be, for example, an intermediate layer (a TiN electrode for DRAM or a barrier film for NAND).

[0195] The underlayer film may, for example, 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.

[0196] The upper layer film may contain, for example, one or more selected from the group consisting of W and Mo.

[0197]

[0198] semiconductor elements

[0199] According to the present invention, a semiconductor device including the semiconductor substrate described above can be provided.

[0200] The semiconductor device may be, for example, a low resistive metal gate interconnect structure, a high aspect ratio 3D metal-insulator-metal (MIM) capacitor, a DRAM trench capacitor, a 3D gate-all-around (GAA), or a 3D NAND flash memory.

[0201]

[0202] Below, preferred examples and drawings are presented to help understand the present invention better. However, the following examples and drawings are merely illustrative of the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the present invention and the technical idea thereof. It goes without saying that such changes and modifications are also included within the scope of the appended claims.

[0203]

[0204] [Example]

[0205] TiCl4 was prepared as the precursor compound.

[0206] As an activator, 5N HI was prepared.

[0207] Using the precursor compound and the activator, an ALD process was carried out with the deposition process sequence according to the present invention as one cycle.

[0208] The specific experimental methods for Example 1 and the comparative example are as follows.

[0209]

[0210] Example 1 (Example 1-1 to Example 1-8)

[0211] The precursor compound TiCl4 was placed in a canister and supplied to a separate evaporator heated to 150°C at a flow rate of 0.05 g / min using a liquid mass flow controller (LMFC) at room temperature. The TiCl4 vaporized in the evaporator was then introduced into the deposition chamber using a vapor mass flow controller (VFC) for 1 second, and argon gas was then supplied at 3000 sccm for 5 seconds to perform an argon purge. The pressure inside the reaction chamber was controlled at 2.5 Torr.

[0212] Next, 5N HI as an activator was placed in a canister and fed to an evaporator heated to 150°C at a flow rate of 0.05 g / min using an MFC (Mass Flow Controller) at room temperature. The activator vaporized in the evaporator was then introduced into the deposition chamber containing the substrate for 2 seconds, after which argon gas was supplied at 3000 sccm for 8 seconds to perform an argon purge. The pressure inside the reaction chamber was controlled at 2.5 Torr.

[0213] Next, 1000 sccm of ammonia as a reactive gas was introduced into the reaction chamber for 3 seconds, and then argon purging was carried out for 9 seconds, while the substrate on which the deposition film was to be formed was heated to 460°C.

[0214] This process was repeated 200 to 400 times to form eight types of self-limiting atomic layer deposition films having the deposition thicknesses shown in FIG. 1 below.

[0215] As is clear from FIG. 1 below, the deposition thicknesses of the deposited films were 100 Å, 110 Å, 125 Å, 140 Å, 142 Å, 144 Å, 170 Å, and 175 Å, respectively.

[0216] The deposition thickness is the thickness of the deposited film measured by an ellipsometer, which is a device capable of measuring optical properties such as the thickness and refractive index of the deposited film using the polarization characteristics of light.

[0217]

[0218] The increase rate of the deposition rate (D / R (dep. rate) increase rate) was calculated for the eight types of deposited films. Specifically, the thickness of the deposited film was divided by the number of cycles to calculate the thickness of the deposited film deposited per cycle, and the decrease rate of the growth rate of the deposited film was calculated. Specifically, this was calculated using Equation 1 above.

[0219] The calculated increase rate of the deposition rate of the eight species was calculated to be 0.535 Å / cycle on average.

[0220]

[0221] Furthermore, the resistivity of the eight types of deposited films was measured, and the results are shown in FIG. 1 below.

[0222] The resistivity was measured by taking into consideration the sheet resistance measured by a sheet resistance measuring device and the thickness measured by an ellipsometer.

[0223] Furthermore, the resistivity values ​​for deposition thicknesses within 100 to 130 Å were 176 Ωcm, 239 Ωcm, and 302 Ωcm, and the average value of these was calculated to be 239 Ωcm.

[0224]

[0225] Furthermore, the density of the eight types of deposited films was measured using an X-ray reflectometry (XRR) device.

[0226] The average density of the eight measured species was 4.68 g / cm 3 was calculated as:

[0227]

[0228] Furthermore, the impurity contents of the eight types of vapor-deposited films were measured.

[0229] Here, impurities are H, C, NH, 18 O, Cl, Ti, etc. were measured using secondary ion mass spectrometry (SIMS) equipment.

[0230] Specifically, when the sputtering time was 50 seconds, during which the ion sputtering penetrated into the deposited film in the axial direction and there was little contamination in the surface layer of the substrate, the value of the impurity was confirmed from the SIMS graph, taking into account the content (counts) of the impurity.

[0231] The confirmed SIMS results are shown in the graph in Figure 2 below. Specifically, the Cl content in the eight types of evaporated films was - The average impurity content was calculated as 10,406 counts / s.

[0232] Cl - In addition, residual process by-products such as O, Si, H, NH, metals, and metal oxides are also reduced, as can be seen in Figure 1 below.

[0233]

[0234] Comparative Example 1

[0235] The same process as in Example 1 was repeated, except that the activating agent used in Example 1 was changed from 5N HI to 5N HCl.

[0236] This resulted in either an increase in Cl impurities or, in very rare cases, etching.

[0237] For reference, if a plasma atmosphere of HCl or Cl2 is formed on a TiN substrate, or if a high temperature condition equivalent to this is presented, there is a problem that TiN may be etched (dry etched).

[0238]

[0239] Comparative Example 2

[0240] The same process as in Example 1 was repeated, except that 5N HI, which was used as an activator in Example 1, was not used, and a total of 10 types of deposited films were produced. The measurement results are shown in Figures 1 and 2 below.

[0241] As is clear from FIG. 1 below, the deposition thicknesses of the deposited films were 88 Å, 90 Å, 100 Å, 101 Å, 102 Å, 104 Å, 109 Å, 111 Å, 121 Å, and 127 Å, respectively.

[0242]

[0243] In addition, the deposition rate increase rate (D / R (dep. rate) increase rate) was calculated for the 10 types of deposition films.

[0244] The average increase in deposition rate of the 10 species was calculated to be 0.34 Å / cycle.

[0245] As a result, it is found that the result is about 30% worse than that of Example 1.

[0246]

[0247] Furthermore, the resistivity of the 10 types of vapor-deposited films was measured.

[0248] As can be seen from Figure 1 below, the resistivities of the deposited films were 515 μΩcm, 517 μΩcm, 592 μΩcm, 650 μΩcm, 800 μΩcm, 802 μΩcm, 890 μΩcm, 900 μΩcm, 970 μΩcm, and 11,100 μΩcm, respectively, which was calculated to be an average of 715 μΩcm, which is approximately 50% inferior to Example 1.

[0249] In addition to these, the resistivity values ​​for deposition thicknesses within 100 to 130 Å were 515 μΩcm, 517 μΩcm, and 592 μΩcm, and the average value of these was calculated to be 541 μΩcm.

[0250]

[0251] In addition, the density of the 10 types of deposited films was measured using an X-ray reflectometry (XRR) device. The average density of the 10 types was 5.03 g / cm 3 It is found that the result is about 9% worse than that of Example 1.

[0252]

[0253] Furthermore, the impurity contents of the 10 types of deposition films were measured, and the confirmed SIMS results are shown in the graph in Figure 2 below. Specifically, the Cl content in the 10 types of deposition films was - The average impurity content was calculated to be 31,638 counts / s, which is about 50% or less inferior to Example 1.

[0254]

[0255] From the above results, it was confirmed that Examples 1 and 2 according to the present invention, which used an activator of a type different from the precursor ligand, not only showed significant improvements in deposition thickness, deposition rate increase rate, and resistivity, but also had excellent impurity reduction properties, compared to Comparative Example 1, which used an activator of the same type as the precursor ligand, and Comparative Example 2, which used no activator at all.

[0256] In particular, Example 1, which used the activator of the present invention, showed excellent properties, including an increase in deposition rate and density of the deposited film per cycle of 10% or more, a decrease in resistivity of 50% or more, and a decrease in impurities of 60% or more, compared to Comparative Example 2, which did not use the activator.

[0257]

[0258] Therefore, when a compound having a different type of ligand from that of the precursor compound is used as the activator of the present invention, the ligand exchange mechanism is utilized to improve the film thickness and deposition rate increase rate, density, and resistivity of the deposited film, and the impurity reduction property is also excellent, so it has been confirmed that the deposited film can be effectively formed even on substrates with complex patterns.

Claims

1. An activator comprising an alkyl-free halide for exchanging the ligands of the precursor compound bound to the Group 4 metal center.

2. 2. The activator according to claim 1, wherein when the precursor compound contains a halogen, the halogen is defined as a first halogen, and the halogen constituting the alkyl-free halide is a second halogen different from the first halogen.

3. The activator according to claim 2, wherein the first halogen is a precursor having one or more ligands selected from the group consisting of fluorine, chlorine, and bromine.

4. The activator according to claim 2, wherein the second halogen is at least one selected from the group consisting of iodine and bromine.

5. 2. The activator according to claim 1, wherein the Group 4 central metal is titanium.

6. 2. The activator according to claim 1, wherein the alkyl-free halide is an alkyl-free iodine donor, hydrogen iodide gas, hydrogen bromide gas, iodine ion, or iodine radical.

7. 2. The activator according to claim 1, wherein the deposition is performed by atomic layer deposition (ALD), plasma-enhanced atomic layer deposition (PEALD), chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), metal-organic chemical vapor deposition (MOCVD), or low-pressure chemical vapor deposition (LPCVD).

8. A semiconductor substrate comprising a structure on the substrate in which the ligand of the precursor compound is exchanged using an activator containing the alkyl-free halide according to any one of claims 1 to 7.

9. 9. The semiconductor substrate of claim 8, wherein the structure represented by Chemical Formula 1 is formed by reacting a precursor compound on the substrate, in which a first halogen is bound to a Group 4 central metal, with an alkyl-free halide containing a second halogen for filling a ligand leaving site of the precursor compound.

10. The semiconductor substrate of claim 8, wherein the semiconductor substrate comprises a deposited film having a structure in which a reactant-derived substance and a second halogen are bonded to a quaternary central metal (M) of Chemical Formula 1.

11. The reactant-derived material is H ２ O, H ２ O ２ , O ２ , O ３ , O radical, D ２ , H ２ , H radical, NH ３ , NO ２ , N ２ O, N ２ , N radical, H ２ 11. The semiconductor substrate according to claim 10, characterized in that it is provided from S or S.

12. The semiconductor substrate according to claim 10, wherein the deposited film has a multi-layer structure of two or more layers.

13. The deposited film has a deposition thickness of 500 Å or less, a resistivity of 300 μΩ cm or less, a deposition rate of 0.34 Å / cycle or more, and a density of 4.0 g / cm. ３ 11. The semiconductor substrate according to claim 10, wherein the number of iodine atoms measured by secondary ion mass spectrometry (SIMS) is 50 counts / s or more.

14. A semiconductor device comprising the semiconductor substrate of claim 8 .

Images