Ultra-thin film, method for forming ultra-thin film, semiconductor substrate and semiconductor device prepared therefrom

Abstract

This invention relates to an ultrathin film, an ultrathin film formation method, a semiconductor substrate including the same, and a semiconductor device. The invention provides an ultrathin film, an ultrathin film formation method, a forming agent, a semiconductor substrate including the same, and a semiconductor device. The ultrathin film is not only made of barrier materials and / or high-dielectric materials, but is also modified to improve initial deposition reactivity. Therefore, even when formed at extremely thin thicknesses, it can further reduce current leakage or improve current characteristics, and its quality can be improved through densification and impurity removal.

Description

Technical Field

[0001] The present invention relates to an ultra-thin film, a method for forming an ultra-thin film, a semiconductor substrate and a semiconductor device prepared by the ultra-thin film. More specifically, the present invention relates to an ultra-thin film, a method for forming an ultra-thin film, a forming agent, a semiconductor substrate and a semiconductor device including the same, etc. The ultra-thin film is not only made of a barrier material and / or a high dielectric constant material, but also modified to improve the initial deposition reactivity, so that even when formed with an extremely thin thickness, it can further reduce current leakage or further improve current characteristics. In addition, improved quality can also be achieved by densification and impurity removal, etc. Prior Art

[0002] With the requirements for improving the performance and high integration of semiconductor devices, there are various problems, such as an increase in specific resistance as the thickness of the deposited material decreases, and pin holes generated through post-treatment processes, etc.

[0003] In particular, it is difficult to form a uniform film for a barrier metal electrode with a thickness of less than 1.5 nm, resulting in the formation of a thick film.

[0004] Therefore, it is necessary to develop an ultra-thin film forming technology that can effectively form a thin film with an ultra-thin thickness regardless of the barrier material or the high dielectric constant material, and can provide a dense film without pin holes during etching evaluation. [Prior Art Documents] [Patent Documents] Korean Patent Publication No. 2016-0022792. Summary of the Invention

[0005] [Problems to be Solved by the Invention]

[0006] To solve the problems of the prior art as described above, an object of the present invention is to provide an ultra-thin film, a method for forming an ultra-thin film, a forming agent, a semiconductor substrate and a semiconductor device including the same, etc. The ultra-thin film is not only made of a barrier material and / or a high dielectric constant material, but also modified to improve the initial deposition reactivity, so that even when formed with an extremely thin thickness, it can further reduce current leakage or further improve current characteristics. In addition, improved quality can also be achieved by densification and impurity removal, etc.

[0007] The above object and other objects of the present invention can be achieved by the present invention described below. [Means for Solving the Problems]

[0008] To achieve the above object, the present invention is characterized in that, I) a thin film formed on a substrate using one or more materials selected from a barrier material and a high dielectric constant material, the thickness of the thin film being 10 nm or less, the thickness being measured by TEM; the root mean square surface roughness of the thin film being 0.3 nm or less.

[0009] In addition, the present invention provides an ultra-thin film, which is characterized in that, II) a thin film formed on a substrate using one or more materials selected from a barrier material and a high dielectric constant material, the thickness of the thin film being 5 nm or less, the thickness being measured by TEM; by using a modified gas, the GPC is increased by 30% or more.

[0010] III), according to I) to II), after the thin film is immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, the surface roughness measured by a scanning probe microscope (Atomic Force Microscope, AFM) can be 0.3 nm or less.

[0011] IV), according to I) to III), the thin film can be selected from one or more of a titanium nitride film, a tantalum nitride film, a ruthenium film, an aluminum oxide film, a calcium oxide film, a yttrium oxide film, a strontium oxide film, a zirconium oxide film, a hafnium oxide film, a tantalum oxide film, a lanthanum oxide film, a barium oxide film, and a titanium oxide film.

[0012] V), according to I) to IV), the thin film can be a multi-component oxide film having two or more of a perovskite structure or a pyrochlore structure.

[0013] VI), according to I) to V), after the thin film is immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, through etching evaluation, the maximum etching height from the uppermost part to the lowermost part (the side close to the substrate) of the thin film measured by a scanning probe microscope (Atomic Force Microscope, AFM) can be 50% or less.

[0014] VII), According to I) to VI), after the film is immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes and evaluated by etching, the maximum etching height from the uppermost part to the lowermost part (the side close to the substrate) of the film measured by a scanning probe microscope (Atomic Force Microscope, AFM) can be 1.5 nm or less.

[0015] In addition, the present invention provides a method for forming an ultra-thin film, characterized in that VIII) the method for forming an ultra-thin film includes: an adsorption step of forming an adsorption material on a substrate by spraying a source gas composed of one or more materials selected from a barrier material and a high dielectric constant material; a modification step of modifying the adsorption material formed on the substrate by spraying a modification gas that reacts with the source gas; and a deposition step of depositing a film composed of one or more materials selected from a barrier material and a high dielectric constant material on the substrate by spraying a reaction gas that reacts with the modification gas; when the adsorption step, the modification step, and the deposition step are taken as one cycle, the following conditions are simultaneously satisfied: the thickness of the film formed when repeating 10 cycles is 10 angstroms or less, and the thickness of the film formed when repeating 20 cycles is 20 angstroms or less.

[0016] In addition, the present invention provides a method for forming an ultra-thin film, characterized in that IX) the method for forming an ultra-thin film includes: a modification step of modifying the surface of the substrate by spraying a modification gas on the surface of the substrate when an adsorption reaction with a source gas occurs on the substrate; an adsorption step of forming an adsorption material on the substrate by spraying the source gas composed of one or more materials selected from a barrier material and a high dielectric constant material; and a deposition step of depositing a film composed of one or more materials selected from a barrier material and a high dielectric constant material on the substrate by spraying a reaction gas that reacts with the source gas; when the modification step, the adsorption step, and the deposition step are taken as one cycle, the following conditions are simultaneously satisfied: the thickness of the film formed when repeating 10 cycles is 10 angstroms or less, and the thickness of the film formed when repeating 20 cycles is 20 angstroms or less.

[0017] X), According to VIII) to IX), as the source gas in the adsorption step, one or more selected from titanium (Ti), tantalum (Ta), aluminum (Al), ruthenium (Ru), niobium (Nb), bismuth (Bi), calcium (Ca), yttrium (Y), strontium (Sr), zirconium (Zr), hafnium (Hf), lanthanum (La), and barium (Ba) can be used.

[0018] XI), According to VIII) to X), in order to reduce the central metal atom at a low process temperature below 400 degrees, the source gas can use a compound with a bond dissociation energy between the central metal atom and the ligand of 350 kJ / mol or less, where the bond dissociation energy is calculated using the Gaussian 16 program (basis set of DFT-D3 / B3LYP (central metal, iodine: LanL2DZ, C, N, O, H, X: 6-31+G(d.p))).

[0019] XII), According to VIII) to XI), the modification step can be carried out by spraying a halogen gas with a weight average molecular weight of 127 g / mol to 250 g / mol and containing iodine as the modification gas onto the substrate.

[0020] XIII), According to VIII) to XII), the modification gas can include a material having a direct bond between hydrogen (H) and iodine, a material having a direct bond between carbon (C) and iodine, or a material having a direct bond between a halogen element (F, Cl, Br) and iodine.

[0021] XIV), According to VIII) to XIII), the material having a direct bond between hydrogen (H) and iodine can be a material within the range of 305 kJ / mol to 325 kJ / mol for the overall binding energy of the compound calculated using the Gaussian 16 program (basis set of DFT-D3 / B3LYP (iodine: LanL2DZ, carbon, hydrogen elements: 6-31+G(d.p))).

[0022] XV), According to VIII) to XIV), the material having a direct bond between carbon (C) and iodine can be a material with an overall binding energy of 165 kJ / mol to 242 kJ / mol and exhibiting a tertiary structure calculated using the Gaussian 16 program (basis set of DFT-D3 / B3LYP (iodine: LanL2DZ, carbon, hydrogen elements: 6-31+G(d.p))).

[0023] XVI), According to VIII) to XV), the material having a direct bond between a halogen element (F, Cl, Br) and iodine can be a material within the range of 50 kJ / mol to 160 kJ / mol for the overall binding energy of the compound calculated using the Gaussian 16 program (basis set of DFT-D3 / B3LYP (iodine: LanL2DZ, carbon, hydrogen elements: 6-31+G(d.p))).

[0024] XVII), According to VIII) to XVI), the deposition step can be carried out by spraying ozone (O₃), oxygen (O₂), nitrogen (N₂), or ammonia (NH₃) as a reaction gas onto the substrate.

[0025] XVIII), According to VIII) to XVII), the ultra-thin film forming method may include: a first purging step of spraying a purging gas onto the substrate after the adsorption step; a second purging step of spraying a purging gas onto the substrate after the modification step; and a third purging step of spraying a purging gas onto the substrate after the deposition step.

[0026] In addition, the present invention provides an ultra-thin film forming method, characterized in that XIX) in order to modify the surface or adsorbed source material, a compound with a bond dissociation energy between the central metal atom and the ligand of 350 kJ / mol or less is used, wherein the bond dissociation energy is calculated using the Gaussian 16 program (basis set of DFT-D3 / B3LYP (central metal, iodine: LanL2DZ, C, N, O, H, X: 6-31+G(d.p))).

[0027] In addition, the present invention provides a semiconductor substrate, characterized in that XX) the semiconductor substrate includes the aforementioned ultra-thin film.

[0028] XXI), According to XX), the ultra-thin film can be a multi-layer structure of two or three layers.

[0029] In addition, the present invention provides a semiconductor device, characterized in that XXII) the semiconductor device includes the aforementioned semiconductor substrate. [Advantages of the Invention]

[0030] According to the present invention, there is an effect of providing an ultra-thin film, an ultra-thin film forming method, a forming agent, a semiconductor substrate and a semiconductor device including the same, etc., wherein the ultra-thin film is not only made of a barrier material and / or a high dielectric constant material, but also modified to improve the initial deposition reactivity, so that even when formed with an extremely thin thickness, it can further reduce current leakage or further improve current characteristics. In addition, improved quality can also be achieved by densification and impurity removal, etc.

[0031] Furthermore, by improving impurities and film quality, there is an effect of providing a method for forming a high-quality ultra-thin film and a semiconductor substrate prepared by the method. Brief Description of Drawings

[0032] Figures 1 to 2 are graphs comparing the formation thickness of the thin films between the examples of the present invention and the comparative examples of the prior art. Figure 3 shows the etching evaluation results between the examples of the present invention and the comparative examples of the prior art, and is a scanning electron microscope (SEM) photograph showing the etching evaluation results after immersion in hydrofluoric acid (HF, 1% dilution) for 5 minutes. Figure 4 shows the etching evaluation results between the examples of the present invention and the comparative examples of the prior art, and is a scanning probe microscope (atomic force microscope (AFM)) photograph showing the etching evaluation results at each time period of immersion in hydrofluoric acid (HF, 1% dilution). Embodiments

[0033] Hereinafter, the ultra-thin film, the method for forming the ultra-thin film, etc. in the present invention will be described in detail.

[0034] In the present invention, the term "ultra-thin film" refers to a film whose thickness of the film made of a barrier material or a high dielectric constant material simultaneously satisfies the following conditions: 10 angstroms / 10 cycles or less, and 20 angstroms / 10 cycles or less.

[0035] The thickness of the film can be measured using TEM, but is not limited thereto.

[0036] In the present invention, unless otherwise specified, the term "modified gas" refers to a material for forming an ultra-thin film.

[0037] In the present invention, unless otherwise specified, the term "modification" means that materials other than the barrier material or the high dielectric constant material and the barrier material and / or the high dielectric constant material have a positive interaction on the reaction surface.

[0038] Among them, the positive interaction can be improvement of the film quality of the thin film, such as reduction of specific resistance, increase of density, reduction of impurities, and densification of the film, etc., but is not limited thereto.

[0039] In the present invention, unless otherwise mentioned, % refers to weight %.

[0040] The inventor of the present invention has confirmed that by using a modified material made not only of a barrier material and / or a high dielectric constant material but also capable of improving the initial deposition reactivity, even when formed with an extremely thin thickness, it is possible to further reduce current leakage or further improve current characteristics, and to form an ultra-thin film with improved quality by densification and impurity removal, etc., and has dedicated to related research, thereby completing the present invention.

[0041] The ultra-thin film of the present invention may include a film formed on a substrate using one or more materials selected from a barrier material and a high dielectric constant material.

[0042] As an example, the barrier material and / or the high dielectric constant material may be a titanium nitride film, a tantalum nitride film, a ruthenium film, an aluminum oxide film, a calcium oxide film, a yttrium oxide film, a strontium oxide film, a zirconium oxide film, a hafnium oxide film, a tantalum oxide film, a lanthanum oxide film, barium oxide, and a titanium oxide film, etc.

[0043] The ultra-thin film may be a multi-component oxide film of two or more kinds having a perovskite structure or a pyrochlore structure.

[0044] The ultra-thin film of the present invention is characterized in that it includes a film formed on a substrate using one or more materials selected from a barrier material and a high dielectric constant material, the thickness of the film measured by TEM is 10 nm or less, and the root mean square average surface roughness of the film is 0.3 nm or less. In this case, a flat ultra-thin film can be provided, and at the same time, it has significant initial deposition reactivity.

[0045] In addition, the present invention is characterized in that it includes a film formed on a substrate using one or more materials selected from a barrier material and a high dielectric constant material, the thickness measured by TEM is 5 nm or less, and by using a modified gas, the GPC is increased by 30% or more. In this case, the effect of providing a flat ultra-thin film is significant.

[0046] The film may be selected from one or more of a titanium nitride film, a tantalum nitride film, an aluminum oxide film, a calcium oxide film, a yttrium oxide film, a strontium oxide film, a zirconium oxide film, a hafnium oxide film, a tantalum oxide film, a lanthanum oxide film, a barium oxide film, or a titanium oxide film.

[0047] The characteristics of the thin film are that after being immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, the surface roughness measured by AFM is 0.3 nm or less. In this case, it belongs to an ultra-thin film and can also provide film tightness.

[0048] The characteristics of the thin film are that after being immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, through etching evaluation, the maximum etching height from the uppermost part to the lowermost part (the side close to the substrate) of the thin film measured by a scanning probe microscope (Atomic Force Microscope, AFM) is, as an example, 50% or less, and as a specific example, 20% or less, preferably 0% or close to 0%. In this case, it belongs to an ultra-thin film and can also provide film tightness, so it is preferred.

[0049] The characteristics of the thin film are that after being immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, through etching evaluation, the maximum etching height from the uppermost part to the lowermost part (the side close to the substrate) of the thin film measured by a scanning probe microscope (Atomic Force Microscope, AFM) is, as an example, 2 nm or less, and as a specific example, 1 nm or less, preferably 0 nm or close to 0 nm. In this case, it belongs to an ultra-thin film and can also provide film tightness, so it is preferred.

[0050] The aforementioned ultra-thin film can be prepared by including an adsorption step, a modification step, and a deposition step.

[0051] In the adsorption step, an adsorption material is formed on the substrate by spraying a source gas composed of one or more materials selected from a barrier material and a high dielectric constant material.

[0052] The adsorption step can be carried out in such a way that the source gas is sprayed onto the substrate through a first gas flow path provided in the spraying part.

[0053] The source gas may include at least one of titanium (Ti), tantalum (Ta), aluminum (Al), ruthenium (Ru), niobium (Nb), bismuth (Bi), calcium (Ca), yttrium (Y), strontium (Sr), zirconium (Zr), hafnium (Hf), lanthanum (La), and barium (Ba).

[0054] The titanium (Ti) and tantalum (Ta) correspond to barrier materials or high dielectric constant materials, and the aluminum (Al), calcium (Ca), yttrium (Y), strontium (Sr), zirconium (Zr), hafnium (Hf), lanthanum (La), and barium (Ba) all belong to high dielectric constant materials.

[0055] The source gas can be a gas made from a precursor material having a ligand with at least one of titanium (Ti), tantalum (Ta), aluminum (Al), ruthenium (Ru), niobium (Nb), bismuth (Bi), calcium (Ca), yttrium (Y), strontium (Sr), zirconium (Zr), hafnium (Hf), lanthanum (La), and barium (Ba) as the central metal atom.

[0056] As an example, for the aforementioned precursor material, in order to reduce the central metal atom at a low process temperature below 400 °C, the ligand can be selected with a bond dissociation energy between the central metal atom and the ligand within 350 kJ / mol, where the bond dissociation energy is calculated using the Gaussian 16 program (basis set of DFT-D3 / B3LYP (central metal, iodine: LanL2DZ, C, N, O, H, X: 6-31+G(d,p))).

[0057] That is, the ligand can be an element including halogen (F, Cl, or Br), C, H, N, O, S, P, and is not limited thereto.

[0058] As an example, the precursor material can be a titanium precursor and a tantalum precursor.

[0059] As a preferred embodiment, the titanium precursor can be titanium halide.

[0060] As an example, the titanium halide can be at least any one selected from the group consisting of TiF4, TiCl4, TiBr4, and TiI4. For example, in terms of economy, TiCl4 is preferred, but it is not limited thereto.

[0061] As a preferred embodiment, the tantalum precursor can be tantalum halide or alkylimino tris(diethylamino)tantalum (R1N=Ta(NEt2)3). Among them, the alkyl can be a straight chain or a branched chain having 1 to 5 carbon atoms.

[0062] As an example, the tantalum halide may be at least any one selected from the group consisting of TaF5, TaCl5, TaBr5, TaI5, and tert-butylimino tris(diethylamino)tantalum (t-BuN=Ta(NEt2)3, TBTDET). For example, in terms of economy, TaCl5 is preferably used, but it is not limited thereto.

[0063] The titanium halide or tantalum halide has excellent thermal stability, does not decompose at room temperature, and has very high vapor pressure characteristics. Therefore, it can be used as a precursor for atomic layer deposition (ALD) or chemical vapor deposition (CVD) to effectively deposit a thin film.

[0064] As an example, the precursor material can be mixed with a non-polar solvent and used. In this case, it has the advantage of being able to easily adjust the viscosity or vapor pressure of the precursor material.

[0065] As another example, the precursor material may have a structure in which at least one of titanium (Ti), tantalum (Ta), aluminum (Al), ruthenium (Ru), niobium (Nb), bismuth (Bi), calcium (Ca), yttrium (Y), strontium (Sr), zirconium (Zr), hafnium (Hf), lanthanum (La), and barium (Ba) is used as a central metal atom and is bonded with ligands (L1, L2, L3, L4, L5, L6, etc.).

[0066] The ligands (L1, L2, L3, L4, L5, L6, etc.) may be iodine-free ligands.

[0067] As an example, L1, L2, L3, L4, L5, L6 may be ligands composed of C, N, O, H, F, Cl, Br, etc.

[0068] As a specific example, when the precursor material is a molecule having Mo, W, Ru, Cu, Rh, Pb, Cd, Sn, Bi, In, Ti, Ta, Ni, Mo, Nb, Zr, V, and Ga as central metal atoms (M) and having one or more ligands composed of C, N, O, H, F, Cl, Br, and the vapor pressure at 25 °C is 0.01 mTorr to 100 Torr, the effect of using the modifying gas can be maximized.

[0069] As other specific examples, the precursor material is a molecule having at least one of titanium (Ti), tantalum (Ta), aluminum (Al), ruthenium (Ru), niobium (Nb), bismuth (Bi), calcium (Ca), yttrium (Y), strontium (Sr), zirconium (Zr), hafnium (Hf), lanthanum (La), and barium (Ba) as a central metal atom and having more than one ligand composed of C, N, O, H, F, Cl, and Br. In order to reduce the central metal atom at a low process temperature of 400 °C or lower, it may be a compound in which the bond dissociation energy between the central metal atom and the ligand calculated using the Gaussian 16 program (basis set of DFT-D3 / B3LYP (central metal, iodine: LanL2DZ, C, N, O, H, X: 6-31+G(d,p))) is within 350 kJ / mol.

[0070] As an example, when the central metal is divalent, L1 and L2 can be attached to the central metal as ligands. When the central metal is hexavalent, L1, L2, L3, L4, L5, and L6 can be attached to the central metal, and the ligands corresponding to L1 to L6 can be the same or different from each other.

[0071] As an example, L1, L2, L3, L4, L5, and L6 can be -H or -R, which are the same or different from each other, where -R can be an alkyl group having 1 to 10 carbon atoms, an alkene having 1 to 10 carbon atoms, or an alkane having 1 to 10 carbon atoms, and can be a linear or cyclic structure. According to the oxidation value of the central metal, the n number of L in L1, L2, L3, and L4 can be 2 to 6.

[0072] As an example, when the central metal is divalent, L1 and L2 can be attached to the central metal as ligands. When the central metal is hexavalent, L1, L2, L3, L4, L5, and L6 can be attached to the central metal, and the ligands corresponding to L1 to L6 can be the same or different from each other.

[0073] As a specific example, L1, L2, L3, L4, L5, and L6 can be -H, -OR, or -NR2, which are the same or different from each other, where -R can be H, an alkyl group having 1 to 10 carbon atoms, an alkene having 1 to 10 carbon atoms, an alkane having 1 to 10 carbon atoms, iPr, or TBu. In this case, it has a reaction energy suitable for substitution with a reaction gas described later.

[0074] As a specific example, L1, L2, L3, L4, L5, and L6 can be -H, or -X, which are the same as or different from each other, where -X can be F, Cl, or Br. In this case, it has a reaction ability suitable for being substituted by the reaction gas described later.

[0075] As a specific example, L1, L2, L3, L4, L5, and L6 can be -H, or -R, which are the same as or different from each other, where -R can be an alkyl group with 1 to 10 carbon atoms, an alkene with 1 to 10 carbon atoms, or an alkane with 1 to 10 carbon atoms, and can have a linear or cyclic structure. In this case, it has a reaction ability suitable for being substituted by the reaction gas described later.

[0076] As a specific example, L1, L2, L3, L4, L5, and L6 can be -H, -OR, or -NR2, which are the same as or different from each other, where -R can be H, an alkyl group with 1 to 10 carbon atoms, an alkene with 1 to 10 carbon atoms, an alkane with 1 to 10 carbon atoms, iPr, or tBu. In this case, it has a reaction ability suitable for being substituted by the reaction gas described later.

[0077] As a specific example, L1, L2, L3, L4, L5, and L6 can be -H, or -X, which are the same as or different from each other, where -X can be F, Cl, or Br. In this case, it has a reaction ability suitable for being substituted by the reaction gas described later.

[0078] The bond dissociation energy of the precursor material is an important factor in depositing the precursor material together with the modifying gas. The computer simulation program used to calculate the bond dissociation energy is Gaussian 16. At this time, the computer simulation method uses DFT-D3 / B3LYP. In terms of the basis set, iodine and the central metal (for example, molybdenum) are LanL2DZ, and other elements are 6-31+G(d,p).

[0079] The reaction activity energy between the precursor material and the reaction gas is also calculated by the same method. At this time, the transition state method is DFT / TS-Berny, and the intrinsic reaction coordinate is 40 pts.

[0080] The precursor material can be transferred into the chamber by the VFC method, the DLI method, or the LDS method.

[0081] The injection (feeding) time (seconds (sec)) of the precursor material onto the substrate per cycle is preferably from 0.01 second to 10 seconds, more preferably from 0.02 second to 8 seconds, still more preferably from 0.04 second to 6 seconds, and most preferably from 0.05 second to 4 seconds. Within this range, there are advantages of improved initial film formation rate, excellent step coverage, and economy.

[0082] Based on the volume of the chamber from 15 L to 20 L, the feeding time is based on a flow rate from 0.1 mg / cycle to 8000 mg / cycle. More specifically, based on the volume of the chamber of 18 L, the feeding time is based on a flow rate from 10 mg / cycle to 5000 mg / cycle.

[0083] The ultra-thin film may contain the aforementioned film composition alone or as a selective area, but is not limited thereto, and may also contain SiH, SiOH, etc.

[0084] As an example, the ultra-thin film can be applied to semiconductor devices as a wiring metal film, a wiring metal diffusion prevention film, or the like.

[0085] The specific resistance of the ultra-thin film can be in the range of 5 μΩ·cm to 1000 μΩ·cm.

[0086] In the adsorption step, when a mixed gas including two or more materials is injected onto the substrate, the first source gas including the first material and the second source gas including the second material can be mixed in a buffer tank provided separately from the injection part to generate a mixed gas, and then supplied to the injection part and injected onto the substrate; or, the first source gas and the second source gas can also be sequentially injected onto the substrate. Thus, a film with improved step coverage rate can be prepared and a film with improved uniformity can be prepared.

[0087] As an example, the modification step can occur on the entire substrate or a part of the substrate where the ultra-thin film to be provided is formed.

[0088] The modification step can be carried out using a modification gas that reacts with the source gas. As an example, the adsorbed material formed on the substrate can be modified by injecting a modification gas that reacts with the source gas.

[0089] As an example, the modifying gas may be a halogen gas having a weight-average molecular weight of 127 g / mol to 250 g / mol and containing iodine. In this case, it belongs to an ultra-thin film and can also provide film denseness.

[0090] As a specific example, the modifying gas may use one or more of a material having a direct bond between hydrogen (H) and iodine, a material having a direct bond between carbon (C) and iodine, or a material having a direct bond between a halogen element (F, Cl, Br) and iodine.

[0091] As an example, the material having a direct bond between hydrogen (H) and iodine may be a material within the range of 305 kJ / mol to 325 kJ / mol for the overall binding energy of the compound calculated using the Gaussian 16 program (basis set of DFT-D3 / B3LYP (iodine: LanL2DZ, carbon and hydrogen elements: 6-31+G(d,p))). In this case, it belongs to an ultra-thin film and can also provide film denseness.

[0092] The material having a direct bond between carbon (C) and iodine may be a material within the range of 165 kJ / mol to 242 kJ / mol for the overall binding energy of the compound calculated using the Gaussian 16 program (basis set of DFT-D3 / B3LYP (iodine: LanL2DZ, carbon and hydrogen elements: 6-31+G(d,p))) and showing a tertiary structure. In this case, it belongs to an ultra-thin film and can also provide film denseness.

[0093] The material having a direct bond between a halogen element (F, Cl, Br) and iodine may be a material within the range of 50 kJ / mol to 160 kJ / mol for the overall binding energy of the compound calculated using the Gaussian 16 program (basis set of DFT-D3 / B3LYP (iodine: LanL2DZ, carbon and hydrogen elements: 6-31+G(d,p))). In this case, it belongs to an ultra-thin film and can also provide film denseness.

[0094] In the modifying gas, the overall binding energy of the compound having a direct bond between hydrogen (H) and iodine calculated using the Gaussian 16 program (basis set of DFT-D3 / B3LYP (iodine: LanL2DZ, carbon and hydrogen elements: 6-31+G(d,p))) may be 305 kJ / mol to 325 kJ / mol. In this case, the film impurity content caused by ligands such as carbon can be reduced, and a low-resistance thin film can be effectively provided.

[0095] The modified gas may be selected from one or more of the compounds represented by Chemical Formulas 1-1 to 1-12 below. In this case, it belongs to an ultra-thin film, and film denseness can also be provided. [Chemical Formulas 1-1 to 1-12]

[0096] As an example, the modified gas is a single substance of hydrogen iodide of 3N to 15N, a gas mixture (1 wt% to 99 wt% of hydrogen iodide of 3N to 15N and the balance of an inert gas making the total amount reach 100 wt%), or an aqueous solution mixture (0.5 wt% to 70 wt% of hydrogen iodide of 3N to 15N and the balance of water making the total amount reach 100 wt%). Herein, the inert gas may be nitrogen, helium or argon with a purity of 4N to 9N. In this case, impurities can be reduced by carrying out a reduction reaction, and a low-resistance thin film or a metal nitride film, etc. can be effectively formed.

[0097] Preferably, the modified gas is a single substance of hydrogen iodide of 5N to 6N, a gas mixture (1 wt% to 99 wt% of hydrogen iodide of 5N to 6N and the balance of non-reactive gas to make the total amount reach 100 wt%), or an aqueous solution mixture (0.5 wt% to 70 wt% of hydrogen iodide of 5N to 6N and the balance of water to make the total amount reach 100 wt%). Among them, the non-reactive gas can be nitrogen, helium or argon with a purity of 4N to 9N. In this case, when forming an ultra-thin film, by suppressing side reactions and adjusting the initial film formation rate, the process by-products in the ultra-thin film can be reduced to reduce corrosion or deterioration, not only improving the film quality (such as enhancing the film crystallinity), but also significantly improving the film thickness uniformity even when forming a film on a highly integrated or complex-structured substrate.

[0098] In this case, at a relatively low process temperature where the precursor is not thermally decomposed, by sufficiently providing the effect of reduction reaction to the precursor material adsorbed on the substrate, when forming a film on a highly integrated or complex-structured substrate, it has the following advantages: significantly improving the film thickness uniformity, preventing the adsorption of process by-products in addition to the precursor, thereby effectively protecting the surface of the substrate, not only reducing the reaction rate but also effectively removing the process by-products.

[0099] Preferably, the modified gas can be a compound with a purity of more than 99.9%, a compound with a purity of more than 99.95%, or a compound with a purity of more than 99.99%. For reference, if a compound with a purity lower than 99% is used, impurities may remain in the film or cause side reactions with the precursor or reactant. Therefore, materials with a purity of more than 99% should be used as much as possible.

[0100] The modified gas can be transferred to the chamber by the VFC method, the DLI method or the LDS method.

[0101] The ratio of the input amount (mg / cycle) of the precursor material to the modified gas in the chamber can be 1:1 to 1:20. In this case, it belongs to an ultra-thin film and can also provide film denseness.

[0102] The spraying (feeding) time (seconds (sec)) of the modified gas onto the substrate per cycle is preferably 0.01 seconds to 10 seconds, more preferably 0.02 seconds to 8 seconds, still more preferably 0.04 seconds to 6 seconds, and most preferably 0.05 seconds to 4 seconds. Within this range, it has the advantages of excellent initial film formation rate, step coverage and economy.

[0103] The feeding time is based on a flow rate of 0.1 mg / cycle to 8000 mg / cycle with respect to the volume of a chamber of 15 L to 20 L. More specifically, with respect to the volume of a chamber of 18 L, it is based on a flow rate of 10 mg / cycle to 5000 mg / cycle.

[0104] The halogen compound provided as the modifying gas may be contained in the film formed by the deposition step described below at 100 ppm or less. If halogen remains excessively, for example, under temperature conditions of 200°C to 300°C, when using the nitriding agent described below, chlorides (such as NH4Cl) are generated and remain in the film, which is not preferred.

[0105] The film can be used for applications such as wiring metal films or low-resistance metal films, and is not limited thereto.

[0106] In particular, while forming a relatively sparse film, the initial film formation rate of the formed film is significantly reduced. Therefore, even when applied to a substrate with a complex structure, uniformity can be ensured, it can be deposited to a particularly thin thickness, and O, Si, metals, metal oxides remaining as process by-products can be reduced. Moreover, even the carbon residue that is currently difficult to reduce can be improved.

[0107] In the deposition step, a film composed of a barrier material and / or a high dielectric constant material can be deposited on the substrate by spraying a reaction gas that reacts with the source gas.

[0108] The deposition step can be performed by spraying a reaction gas onto the substrate. Through the adsorption step, the modification step, and the deposition step, a film can be formed on the substrate by atomic layer deposition (ALD).

[0109] In the deposition step, ozone (O3), oxygen (O2), nitrogen (N2), or ammonia (NH3) can be sprayed as the reaction gas onto the substrate.

[0110] As an example, based on the volume of the precursor material introduced into the interior of the chamber, the amount of the reaction gas can be 10 times to 10000 times, preferably 50 times to 50000 times, more preferably 100 times to 10000 times. Within this range, an oxidation-reduction reaction can be effectively carried out to form the film uniformly and prevent deterioration of the film quality.

[0111] The reaction gas can be transferred to the ALD chamber by the VFC method, the DLI method, or the LDS method. More preferably, it is transferred to the chamber by the VFC method.

[0112] A thin film is prepared by depositing a barrier material and / or a high-k material through the modification step. Thus, the ultra-thin film forming method according to the present invention can provide the following effects.

[0113] First, in the comparative example where there is no such modification step and a thin film made of a barrier material and / or a high-k material is prepared, by the ultra-thin film forming method of the present invention, not only is it made of a barrier material and / or a high-k material, but it is also modified to improve the reactivity in the initial stage of deposition. Thus, compared with the thin film of the comparative example, even when formed with a thinner thickness, a thin film with further reduced current leakage or further improved current characteristics can be prepared. Therefore, the ultra-thin film forming method of the present invention can contribute to the preparation of more refined and thinner semiconductor devices.

[0114] Second, according to the ultra-thin film forming method of the present invention, by including the modification step, a thin film is formed with a barrier material and / or a high-k material, and at the same time, a densification effect and a homogenization effect for improving the film density are provided. When a modified gas is used, a material with low bonding force is induced into a material with high bonding force. Therefore, a thin film with further improved quality can be prepared by film densification and impurity removal, etc.

[0115] Third, according to the ultra-thin film forming method of the present invention, by including the modification step, the redox reaction required for effective deposition of the precursor adsorbed on the substrate can be effectively carried out at a lower process temperature at which the precursor is not thermally decomposed, appropriately increasing the initial film formation rate. Thus, even when depositing on a highly integrated or substrate with a complex structure, there is an effect of significantly improving the film uniformity and providing a low-resistance deposited film.

[0116] The ultra-thin film forming method may include: a first purge step, a second purge step, and a third purge step.

[0117] The first purge step can be carried out by spraying a purge gas on the substrate after the adsorption step.

[0118] After the first purge step, the modification step can be carried out.

[0119] The second purging step can be carried out by spraying a purging gas onto the substrate after the modification step.

[0120] After the second purging step is carried out, the deposition step can be carried out.

[0121] The third purging step can be carried out by spraying a purging gas onto the substrate after the deposition step.

[0122] As an example, the purging gas used in the first purging step, the second purging step, and the third purging step can be an inert gas including argon and nitrogen.

[0123] The purging gas is not particularly limited as long as it is sufficient to remove the amount of the unadsorbed material (gas). However, as an example, based on the volume of the precursor material introduced into the chamber, it can be 10 times to 10,000 times, preferably 50 times to 50,000 times, more preferably 100 times to 10,000 times. Within this range, the unadsorbed material (gas) can be sufficiently removed to form a uniform thin film and prevent deterioration of the film quality. Here, the input amounts of the purging gas and the precursor material are each based on one cycle, and the volume of the precursor material refers to the volume of the vaporized precursor material vapor.

[0124] As an example, each purging step is preferably carried out at 1000 sccm to 50000 sccm (Standard Cubic Centimeter per Minute), more preferably 2000 sccm to 30000 sccm, and even more preferably 2500 sccm to 15000 sccm. Within this range, the initial film formation rate for each cycle can be appropriately controlled, and deposition is achieved in the form of an atomic monolayer or in a manner close to the atomic monolayer, which has the advantage of being beneficial in terms of film quality.

[0125] The entire foregoing steps (adsorption step, first purge step, modification step, second purge step, deposition step, and third purge step) can be repeatedly performed in a unit cycle until an ultra-thin film with a desired thickness is obtained. Thus, when the modification gas and the precursor material are sequentially introduced within one cycle to improve the film quality, the following advantages are achieved: process by-products generated can be effectively removed, thereby reducing the specific resistance; the step coverage is significantly improved and the uniformity is enhanced; at the same time, the film quality (electrical characteristics, density, etc.) is improved, and a low-resistance film is provided.

[0126] The chamber can be an ALD chamber, a CVD chamber, a PEALD chamber, or a PECVD chamber.

[0127] The substrate loaded in the chamber can be heated to 100°C to 600°C.

[0128] As an example, the reaction temperature of the entire foregoing steps (adsorption step, first purge step, modification step, second purge step, deposition step, and third purge step) can be 100°C to 600°C.

[0129] It may include a step of vaporizing and injecting the precursor material or the modification gas and then performing plasma post-treatment. In this case, the initial film formation rate can be improved and process by-products can be reduced.

[0130] As an example, the substrate loaded in the chamber can be heated to 100°C to 700°C. As a specific example, it can be heated to 300°C to 600°C. And the modification gas or the precursor material can be injected onto the substrate in a non-heated or heated state. According to the deposition efficiency, of course, it can also be injected in a non-heated state and then the heating conditions can be adjusted during the deposition process. As an example, at a temperature condition of 50°C to 400°C, it can be injected onto the substrate for 1 second to 20 seconds.

[0131] The ratio of the input amounts (milligrams / cycle) of the precursor material and the modification gas in the chamber can be 1:1 to 1:400, more preferably 1:2 to 1:350, still more preferably 1:2 to 1:300, and most preferably 1:2.5 to 1:200. Within this range, the effect of improving the step coverage and the effect of reducing process by-products are significant.

[0132] As an example, in the ultra-thin film forming method, when using the precursor material and the modifying gas, the deposition rate increase rate represented by the following Mathematical Formula 1 can be 25% or more, and as a specific example, it can be 30% or more. In this case, there are advantages of improving film quality (electrical characteristics, density, etc.) and providing a low-resistance thin film. [Mathematical Formula 1] Deposition rate increase rate = [{(DR i) - (DR f)} / (DR i)] × 100

[0133] In the above mathematical formula, the deposition rate (Deposition rate, DR, Å / cycle) is the speed of ultra-thin film deposition. During the deposition process of the ultra-thin film formed by the precursor and the modifying gas, the initial deposition rate (initial deposition rate, DR i) is the deposition speed of the ultra-thin film formed without introducing the modifying gas. The final deposition rate (final deposition rate, DR f) is the deposition speed of the ultra-thin film formed when the modifying gas is introduced during the above-mentioned process. Among them, the deposition rate (DR) is a value measured by an ellipsometer under normal temperature and pressure conditions for an ultra-thin film with a thickness of 10 nm or less, or 5 nm or less, and the unit used is Å / cycle.

[0134] In Mathematical Formula 1, when the modifying gas is used or not used, the growth rate of the ultra-thin film per cycle refers to the deposition thickness (Å / cycle) of the ultra-thin film in each cycle, that is, the deposition rate. As an example, the deposition rate can be obtained by dividing the final thickness of the ultra-thin film measured by an ellipsometer (Ellipsometery) under normal temperature and pressure conditions for an ultra-thin film with a thickness of 10 nm or less, or 5 nm or less by the total number of cycles to obtain the average deposition rate.

[0135] In Mathematical Formula 1, "when the modifying gas is not used" means the case where a film is prepared only by adsorbing a precursor compound on a substrate in the ultra-thin film deposition process. As a specific example, it means the case where a film is formed by omitting the step of adsorbing the modifying gas and the step of not adsorbing the modifying gas in the ultra-thin film forming method.

[0136] As an example, the ultra-thin film forming method can be carried out at a deposition temperature in the range of 100°C to 600°C, preferably at a deposition temperature in the range of 300°C to 500°C, more preferably at a deposition temperature in the range of 300°C to 400°C. Within this range, while providing the ALD process characteristics, there is an effect of growing into an excellent film quality.

[0137] As an example, the ultra-thin film forming method can be carried out at a deposition pressure in the range of 0.01 Torr to 20 Torr, preferably at a deposition pressure in the range of 0.1 Torr to 20 Torr, more preferably at a deposition pressure in the range of 0.1 Torr to 10 Torr, and most preferably at a deposition pressure in the range of 0.3 Torr to 7 Torr. Within this range, there is an effect of obtaining an ultra-thin film with a uniform thickness.

[0138] In the present invention, the deposition temperature and deposition pressure can be measured as the temperature and pressure formed in the deposition chamber, or can be measured as the temperature and pressure applied to the substrate in the deposition chamber.

[0139] Preferably, the ultra-thin film forming method may include the following steps: before introducing the precursor material into the chamber, raising the temperature inside the chamber to the deposition temperature; and / or before introducing the precursor material into the chamber, purging by injecting an inert gas into the chamber.

[0140] In the ultra-thin film forming method, the intensity (c / s) of residual impurities (carbon or halogen elements) in the ultra-thin film based on an ultra-thin film thickness of 100 Å measured by SIMS is preferably 100,000 or less, more preferably 70,000 or less, still more preferably 50,000 or less, most preferably 10,000 or less. As a preferred embodiment, it can be 5,000 or less, more preferably 10 to 4,000, still more preferably 10 to 3,000. Within this range, the effect of preventing deterioration of crystallinity and electrical characteristics is excellent.

[0141] In addition, if necessary, the modification step can be carried out before the adsorption step.

[0142] That is, a method for forming an ultra-thin film can be provided, characterized in that the method for forming an ultra-thin film includes: a modification step of forming a modified material on a substrate by spraying a modified gas, an adsorption step of forming an adsorbed material on the substrate by spraying a source gas composed of one or more materials selected from a barrier material and a high dielectric constant material onto the substrate, and a deposition step of depositing a film composed of one or more materials selected from a barrier material and a high dielectric constant material on the substrate by spraying a reaction gas that reacts with the adsorbed material; when taking the adsorption step, the modification step, and the deposition step as one cycle, the following conditions are simultaneously satisfied: the thickness of the film formed when repeating 10 cycles is 10 Å or less, and the thickness of the film formed when repeating 20 cycles is 20 Å or less.

[0143] In addition, the present invention can provide a method for forming an ultra-thin film, characterized in that, in order to modify the surface or the adsorbed source material, a compound with a bond dissociation energy between the central metal atom and the ligand of 350 kJ / mol or less is used, wherein the bond dissociation energy is calculated using the Gaussian 16 program (basis set of DFT-D3 / B3LYP (central metal, iodine: LanL2DZ, C, N, O, H, X: 6-31+G(d,p))).

[0144] In addition, in the present invention, a preparation apparatus capable of performing the method for forming an ultra-thin film may include: an ALD chamber; a first vaporizer for vaporizing a precursor material; a first moving unit for transferring the vaporized precursor material into the ALD chamber; a second vaporizer for vaporizing a modified gas; a second moving unit for transferring the vaporized modified gas into the ALD chamber; and a third moving unit for transferring a reaction gas into the ALD chamber.

[0145] Among them, the vaporizer and the moving unit are not particularly limited as long as they are vaporizers and moving units commonly used in the technical field to which the present invention pertains.

[0146] As a specific example, to illustrate the method for forming an ultra-thin film, first, a substrate having a film formed thereon is placed in a deposition chamber capable of performing atomic layer deposition.

[0147] The substrate may include a semiconductor substrate such as a silicon substrate and silicon oxide.

[0148] A conductive layer or an insulating layer may also be formed on the upper part of the substrate.

[0149] To deposit a thin film on a substrate located in the deposition chamber, the above-mentioned modified gas, precursor material, or a mixture thereof with a non-polar solvent is prepared respectively.

[0150] Then, after injecting the prepared modified gas, precursor material, or a mixture thereof with a non-polar solvent into the vaporizer, it is transferred to the deposition chamber by changing it into a vapor phase and adsorbed on the substrate, and the unadsorbed material (gas) is removed through each purging step.

[0151] Preferably, the non-polar solvent can be selected from one or more of the group consisting of alkanes and cycloalkanes. In this case, it has the following advantages: it contains an organic solvent with low reactivity and solubility and is easy to manage moisture. At the same time, when forming an ultra-thin film, even if the deposition temperature increases, the step coverage can be improved.

[0152] As a more preferred example, the non-polar solvent may include alkanes having 1 to 10 carbon atoms or cycloalkanes having 3 to 10 carbon atoms, preferably cycloalkanes having 3 to 10 carbon atoms. In this case, it has the advantages of low reactivity and solubility and easy moisture management.

[0153] In the present invention, C1, C3, etc. refer to the number of carbon atoms.

[0154] Preferably, the cycloalkane can be a monocycloalkane having 3 to 10 carbon atoms. Among the monocycloalkanes, cyclopentane is a liquid at room temperature and has the highest vapor pressure. Therefore, it is preferably used in the vapor deposition process, but is not limited thereto.

[0155] As an example, the solubility of the non-polar solvent in water (25 °C) is 200 mg / L or less, preferably 50 mg / L to 400 mg / L, and more preferably 135 mg / L to 175 mg / L. Within this range, it has the advantages of low reactivity with respect to the precursor material and easy moisture management.

[0156] In the present invention, the solubility is not particularly limited in the case of the measurement method or standard commonly used in the technical field to which the present invention pertains. As an example, the saturated solution can be measured by the HPLC method.

[0157] Preferably, relative to the total weight of the precursor compound and the nonpolar solvent, the content of the nonpolar solvent may be 5 wt% to 95 wt%, more preferably 10 wt% to 90 wt%, still more preferably 40 wt% to 90 wt%, and most preferably 70 wt% to 90 wt%.

[0158] If the content of the nonpolar solvent input exceeds the upper limit value, impurities will be induced, thereby increasing the resistance and the film impurity value. If the content of the organic solvent input is lower than the lower limit value, there is a disadvantage in that the effect of improving the step coverage caused by the addition of the solvent and the effect of reducing impurities (such as chlorine (Cl) ions) are low.

[0159] As described above, as an example, the ultra-thin film forming method may perform the following steps in a unit cycle: sequentially injecting the precursor material and the modifying gas into the chamber and adsorbing them on the surface of the substrate, and purging the unadsorbed materials; in order to form an ultra-thin film with a desired thickness, the unit cycle may be repeated.

[0160] As an example, the unit cycle may be repeated 1 to 99999 times, preferably 10 to 1000 times, more preferably 50 to 5000 times, still more preferably 100 to 2000 times. Within this range, there is an effect of well exhibiting the desired film characteristics.

[0161] The present invention also provides a semiconductor substrate, characterized in that it is prepared by the ultra-thin film forming method of the present invention. In this case, there are effects that the uniformity of the film thickness is very excellent and the density and electrical characteristics are excellent.

[0162] As an example, the thickness of the ultra-thin film may be 10 nm or less. As another example, it may be 5 nm or less. As a specific example, it may be 0.001 nm to 5 nm, preferably 0.01 nm to 1.5 nm. Within this range, there is an excellent effect of providing an ultra-thin film with excellent barrier characteristics or high dielectric characteristics while having an extremely thin film thickness.

[0163] As an example, based on a 1.5 nm ultra-thin film, the specific resistance value of the ultra-thin film may be 0.1 μΩ·cm to 1000 μΩ·cm, preferably 0.1 μΩ·cm to 900 μΩ·cm, more preferably 0.1 μΩ·cm to 800 μΩ·cm. Within this range, there is an effect of excellent film characteristics.

[0164] Preferably, the impurity content of the ultrathin film can be 10,000 ppm or less, or 1 ppm to 9,000 ppm, more preferably 1 ppm to 8,500 ppm, and even more preferably 1 ppm to 1,000 ppm. Within this range, it has excellent film crystallinity and the effect of improving specific resistance. Among them, the impurities remaining in the ultrathin film are impurities remaining due to insufficient reduction of the metal precursor ligand. As an example, they can be carbon, nitrogen, oxygen, or halogen elements. The lower the residual amount of impurities in the ultrathin film, the better the film quality.

[0165] The ultrathin film is characterized in that when the ligand-derived film impurity content is measured by XPS, impurities such as carbon are reduced to 1% or less.

[0166] The ultrathin film is characterized in that it satisfies the following conditions: after being immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes and evaluated by etching, the maximum etching height from the top to the bottom (the side close to the substrate) of the film measured by a scanning probe microscope (Atomic Force Microscope, AFM) is 50% or less, and no pinholes are generated in the film even after the etching treatment.

[0167] The ultrathin film is characterized in that it satisfies the following conditions: after being immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes and evaluated by etching, the maximum etching height from the top to the bottom (the side close to the substrate) of the film measured by a scanning probe microscope (Atomic Force Microscope, AFM) is 1.5 nm or less, and no pinholes are generated in the film even after the etching treatment.

[0168] In the present invention, unless otherwise mentioned, the % unit refers to the weight basis.

[0169] As an example, the step coverage of the ultrathin film is 90% or more, preferably 92% or more, and more preferably 95% or more. Within this range, even a complex structure can be easily deposited on the substrate. Therefore, it has the advantage of being applicable to a new generation of semiconductor devices.

[0170] The thickness of the prepared ultra-thin film is preferably 1.5 nm or less. Based on the ultra-thin film of 1.5 nm, the impurity content (such as carbon, nitrogen, oxygen, and halogen) is 10,000 ppm or less, and the step coverage is 90% or more. Within this range, it has excellent performance as a barrier film, dielectric film, or blocking film, but is not limited thereto.

[0171] The ultra-thin film is characterized in that the crystallinity measured by XRD is improved.

[0172] The ultra-thin film is characterized in that the specific resistance is improved.

[0173] Hereinafter, embodiments of the thin film of the present invention will be described in detail.

[0174] The thin film of the present invention can be prepared by the above-described ultra-thin film forming method of the present invention.

[0175] The thin film of the present invention may include a thin film layer formed on a substrate.

[0176] The thin film layer can be formed on the substrate by using a mixture including a barrier material or a high dielectric constant material.

[0177] The thickness of the thin film layer measured by TEM can satisfy 10 Å / 10 cycles or less and 20 Å / 10 cycles or less. After being immersed in hydrofluoric acid (HF, 1% diluted solution) for 5 minutes, a thin film with a surface roughness of 0.3 nm or less measured by tilted SEM can be provided. Thus, the thin film of the present invention can be realized to form a thinner thickness and have a dielectric constant that can reduce current leakage or improve electrical characteristics, and thus helps to prepare a more fine and thinner semiconductor device.

[0178] The thin film layer can be deposited on the substrate through the adsorption step, the modification step, and the deposition step.

[0179] The thin film layer includes a thin film formed on a substrate using one or more materials selected from a barrier material and a high dielectric constant material. The thin film satisfies the following conditions: the thickness measured by TEM is 10 Å / 10 cycles or less and 20 Å / 10 cycles or less, and after being immersed in hydrofluoric acid (HF, 1% diluted solution) for 5 minutes, a thin film with a surface roughness of 0.3 nm or less measured by tilted SEM is provided.

[0180] The thin film is selected from one or more of titanium nitride film, tantalum nitride film, ruthenium, alumina film, calcium oxide film, yttrium oxide film, strontium oxide film, zirconium oxide film, hafnium oxide film, tantalum oxide film, lanthanum oxide film, barium oxide and titanium oxide film.

[0181] After the ultra-thin film is immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, through etching evaluation, the maximum etching height from the uppermost part to the lowermost part (the side close to the substrate) of the thin film measured by a scanning probe microscope (Atomic Force Microscope, AFM) is 50% or less, and it is confirmed that no pinholes are generated.

[0182] After the ultra-thin film is immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, through etching evaluation, the maximum etching height from the uppermost part to the lowermost part (the side close to the substrate) of the thin film measured by a scanning probe microscope (Atomic Force Microscope, AFM) is 1.5 nm or less, and it is confirmed that no pinholes are generated.

[0183] In this case, compared with the case where the modification step is not included, the thin film of the present invention can be realized to have a resistance or dielectric constant suitable for use as an electrode or a dielectric film, while forming a thinner, denser and more uniform thin film, thereby improving the quality of the ultra-thin film and ensuring various applicable scenarios.

[0184] The thin film layer can be formed of a barrier material and / or a high dielectric constant material, and is modified using a modifying gas. When modified using a modifying gas, impurities are removed from the thin film, the binding force of the low-binding force material is broken, and only the material with a high binding force remains. Thus, the thin film of the present invention can have a thinner thickness and improved quality through film densification, crystallization and impurity removal, etc.

[0185] Hereinafter, two specific experimental examples are disclosed, but these are only examples and are not limited thereto.

[0186] Example 1

[0187] As a specific example, 5N HI was used as the modifying gas, and TiCl4 was used as the precursor material, and the following ultra-thin film forming process was carried out.

[0188] That is, the prepared precursor materials are loaded into separate tanks and supplied at a flow rate of 0.1 g / minute to a separate vaporizer heated to 150°C at room temperature using a Liquid Mass Flow Controller (LMFC). The TiCl4 precursor vaporized into the vapor phase in the vaporizer is introduced into the deposition chamber for 3 seconds, and then argon is supplied at 5000 sccm for 10 seconds and argon purging is performed. At this time, the pressure inside the reaction chamber is controlled at 2.5 Torr.

[0189] Next, the prepared modifying gas is loaded into a tank and supplied to the chamber at a flow rate of 1000 sccm at room temperature using a Mass Flow Controller (MFC). The modifying gas vaporized into the vapor phase in the vaporizer is introduced into the deposition chamber loaded with the substrate for 2 seconds, and after a reduction reaction, argon is supplied at 5000 sccm for 10 seconds and argon purging is performed. At this time, the pressure inside the reaction chamber is controlled at 2.5 Torr.

[0190] Next, NH3 as the prepared reaction gas is supplied to the chamber at a flow rate of 1000 sccm. The reaction gas vaporized into the vapor phase in the vaporizer is introduced into the deposition chamber loaded with the substrate for 2 seconds, and after a reduction reaction, argon is supplied at 5000 sccm for 10 seconds and argon purging is performed. At this time, the pressure inside the reaction chamber is controlled at 2.5 Torr.

[0191] The deposition temperature is maintained at 500°C, and this process is repeated 10 to 400 times to form an atomic layer thin film.

[0192] For the prepared ultra-thin film (TiN film), the film thickness, resistivity, and surface roughness of each deposition cycle were measured and shown in Table 1.

[0193] Specifically, for the ultra-thin film (TiN film), the thickness of the film was measured using a Transmission Electron Microscope (TEM) and, as shown in Table 1 below, satisfied less than about 10 Å / 10 cycles and less than about 20 Å / 10 cycles.

[0194] For reference, Figure 1 below is a graph comparing the film formation thickness between an example of the present invention and a comparative example of the prior art, and by changing parameters, the film formation thickness of each deposition cycle is also shown in Figure 2 below.

[0195] For reference, FIG. 3 below shows the etching evaluation results between an embodiment of the present invention and a comparative example of the prior art. After immersion in hydrofluoric acid (HF, 1% dilution) for 5 minutes, a scanning electron microscope (SEM) photograph showing the etching evaluation results is presented.

[0196] Furthermore, for the prepared ultra-thin film (TiN film), the surface roughness measured by AFM was calculated to be 0.3 nm or less according to the immersion times before immersion in hydrofluoric acid (HF, 1% dilution), 1 minute, 5 minutes, and 10 minutes, as shown in FIG. 4 below.

[0197] In addition, it was observed that after the ultra-thin film was immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, through etching evaluation, the maximum etching height from the uppermost part to the lowermost part (the side close to the substrate) of the film measured by a scanning probe microscope (Atomic Force Microscope, AFM) was 50% or less.

[0198] In addition, it was observed that after the ultra-thin film was immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, through etching evaluation, the maximum etching height from the uppermost part to the lowermost part (the side close to the substrate) of the film measured by a scanning probe microscope (Atomic Force Microscope, AFM) was 1.5 nm or less.

[0199] Furthermore, using the following Mathematical Formula 1, the result of measuring the growth rate of deposition rate (GPC) confirmed an improvement degree of 30% or more.

[0200] [Mathematical Formula 1] Growth rate of deposition rate = [((DR i) - (DR f)) / (DR i)] × 100

[0201] In the mathematical formula, the deposition rate (DR, Å / cycle) is the speed of ultra-thin film deposition. During the deposition process of the ultra-thin film formed by the precursor and the modifying gas, the initial deposition rate (DRi) is the deposition speed of the ultra-thin film formed without introducing the modifying gas. The final deposition rate (DRf) is the deposition speed of the ultra-thin film formed when the modifying gas is introduced during the process as described above. Among them, the deposition rate (DR) is a value measured using an ellipsometer under normal temperature and pressure conditions for an ultra-thin film with a thickness of 10 nm or less, or 5 nm or less, and the unit used is Å / cycle. Table 1 Ultra-thin film former - TiN@500°C (Example 1) ALD cycle 6 11 17 22 43 65 117 160 Thickness (Å) 8 10 15 20 36 57 95 130 Specific resistance (μΩ·cm) Unable to measure Unable to measure Unable to measure Unable to measure 778 196 92 71 Surface roughness (nm) 2.4 3.5 4.0 3.0 3.5 7.7 6.0 (In the said table, unable to measure refers to the interval that cannot be measured by the equipment due to an excessive specific resistance value.)

[0202] Comparative Example 1

[0203] The modification step of introducing the modified gas was omitted. Except for this, the same process as in Example 1 was repeated, and the same measurement results as in Example 1 described above are shown in Table 2 below.

[0204] For the prepared thin film (TiN film), the thickness of the metal film deposited per cycle was calculated by dividing the thickness of the film measured using an ellipsometer (as a device that can utilize the polarization characteristics of light to measure the optical properties (such as thickness or refractive index) of the metal film) by the number of cycles. The results showed 6 Å / 10 cycles or less and 10 Å / 10 cycles or less, thus confirming a poor initial film formation rate compared to the ultra-thin films in Example 1 to Example 2.

[0205] In addition, for the prepared ultra-thin film (TiN film), after measuring the surface resistance using the four-probe measurement method, the specific resistance value was calculated using the measured thickness.

[0206] Furthermore, for the prepared ultra-thin film (TiN film), after immersion in hydrofluoric acid (HF, 1% dilution) according to time, the surface roughness measured by AFM increased with the immersion time. As shown in Figure 4 below, when immersed for 10 minutes, it was calculated to exceed 0.4 nm, which was confirmed to be poor compared to Example 1.

[0207] In addition, it was observed that after the ultra-thin film was immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, through etching evaluation, the maximum etching height from the top to the bottom (the side close to the substrate) of the film measured by a scanning probe microscope (Atomic Force Microscope, AFM) exceeded 90%.

[0208] In addition, it was observed that after the ultrathin film was immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes and evaluated by etching, the maximum etching height from the top to the bottom (the side close to the substrate) of the film measured by a scanning electron microscope (SEM) and a scanning probe microscope (Atomic Force Microscope, AFM) exceeded 1.5 nm.

[0209] Furthermore, using the aforementioned mathematical formula 1, the result of measuring the growth rate of deposition rate (GPC) confirmed that this value was significantly lower than 30%.

[0210] Table 2 Refer to TiN@500°C (Comparative Example 1) ALD cycle 10 20 30 45 90 150 250 Thickness (Å) 5 10 20 28 48 67 118 Specific resistance (μΩ·cm) Unable to Measure Unable to Measure Unable to Measure Unable to Measure 5065 295 161 Surface roughness (nm) 4.1 4.8 6.2 5.5 6.3 8.2 (In the said table, unable to measure refers to the interval where the specific resistance value is too large to be measured by the equipment.)

[0211] As shown in Tables 1 to 2 described above, according to the present invention, it is confirmed that the thickness of each deposition cycle is very high, the critical thickness for measuring the specific resistance is relatively low, and the surface roughness is improved because a flat thin film is formed with a thinner thickness.

[0212] Example 2

[0213] Before the adsorption step, a modified gas was introduced, and except for this, the same process as in Example 1 was repeated.

[0214] For the prepared ultra-thin film (TiN film), the thickness of the metal film deposited in one cycle was calculated by dividing the film thickness measured by TEM by the number of cycles, and the results satisfied 10 Å / 10 cycles or less and 20 Å / 10 cycles or less.

[0215] In addition, for the prepared ultra-thin film (TiN film), after measuring the surface resistance by the four-probe measurement method, the specific resistance value was calculated using the measured thickness.

[0216] Furthermore, for the prepared ultra-thin film (TiN film), after immersion in hydrofluoric acid (HF, 1% dilution) for 5 minutes, the result measured by tilted SEM confirmed that there were no pin-holes.

[0217] In addition, it was observed that after the ultra-thin film was immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, through etching evaluation, the maximum etching height from the top to the bottom (the side close to the substrate) of the film measured by a scanning probe microscope (atomic force microscope (AFM)) was 50% or less.

[0218] In addition, it was observed that after the ultra-thin film was immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, through etching evaluation, the maximum etching height from the top to the bottom (the side close to the substrate) of the film measured by a scanning probe microscope (atomic force microscope (AFM)) was 1.5 nm or less.

[0219] Furthermore, using the aforementioned mathematical formula 1, the result of measuring the deposition rate increase rate (GPC) confirmed that this value significantly exceeded 30%.

[0220] From the results of Example 1 to Example 2, it can be confirmed that a ultra-thin film can be provided. Different from Comparative Example 1 of the prior art, when a specific modified gas is used in a precursor material having a specified bond dissociation energy, the following conditions are satisfied: the thickness measured by TEM is 10 Å / 10 cycles or less and 20 Å / 10 cycles or less, thereby improving the initial film formation rate. At the same time, after immersion in hydrofluoric acid (HF, 1% dilution) for 5 minutes, the surface roughness measured by tilted SEM is 0.3 nm or less, etc., and film densification (no pinholes are generated) and uniformity can be achieved.

[0221] Furthermore, it can be confirmed that not only the specific resistance is improved, but also the impurities remaining in the thin film are reduced.

[0222] In addition to the above-mentioned TiN (titanium nitride film), it is confirmed that tantalum nitride film, aluminum oxide film, calcium oxide film, yttrium oxide film, strontium oxide film, zirconium oxide film, hafnium oxide film, tantalum oxide film, lanthanum oxide film, barium oxide film, and titanium oxide film can also be provided. Additionally, it can be confirmed that a ultra-thin film with film densification and uniformity is provided. Furthermore, it can be confirmed that not only the specific resistance is improved, but also the impurities remaining in the thin film are reduced.

[0223] In addition, it is respectively confirmed that after the aforementioned TiN (titanium nitride film), tantalum nitride film, aluminum oxide film, calcium oxide film, yttrium oxide film, strontium oxide film, zirconium oxide film, hafnium oxide film, tantalum oxide film, lanthanum oxide film, barium oxide film, and titanium oxide film are immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, through etching evaluation, the maximum etching height from the uppermost part to the lowermost part (the side close to the substrate) of the thin film measured by a scanning probe microscope (atomic force microscope (AFM)) is 50% or less. At the same time, after immersion in hydrofluoric acid (HF, 1% dilution) for 5 minutes, through etching evaluation, the maximum etching height from the uppermost part to the lowermost part (the side close to the substrate) of the thin film measured by a scanning probe microscope atomic force microscope (AFM)) is 1.5 nm or less.

[0224] In other words, in the modified gases represented by Chemical Formulas 1-1 to 1-12, the results of calculating the bond dissociation energy of the carbon or hydrocarbon compound bonded to iodine are shown in Table 3 below.

[0225] Table 3 Structure BDE(C-I) (kJ / mol) Structure BDE(C-I) (kJ / mol) I-1 250.15 I-7 236.38 I-2 247.37 I-8 239.29 I-3 250.08 I-9 241.02 I-4 243.02 I-10 194.21 I-5 244.65 I-11 186.78 I-6 247.09

[0226] Furthermore, as a computer simulation confirmation experiment, the Gaussian 16 program (basis set of DFT-D3 / B3LYP (central metal, iodine, chlorine: LanL2DZ, C, N, O, H, Si: 6-31+G(d,p))) was used, and the energy value of the transition structure was calculated through TS (Berny) optimization.

[0227] Specifically, a model of a silica cluster (SiO₂ cluster (Si₉H₁₂-(OH)₂)) was used as a substrate to optimize the structure in the form of adsorption of the MoCl₅ precursor, and the activation energies required in the reactions with H₂ and HI were calculated. The schematic diagrams based on the measurement results are shown in Table 4 below.

[0228] The activation energy value calculated by the computer simulation is defined as the minimum energy (Ea) required for the reaction path from the state where the precursor material is chemisorbed on the substrate (Ads) to the product (final), that is, the energy difference to the activated state (TS), and the energies of their respective states were calculated and confirmed.

[0229] In the inventive material used to reduce the reaction activation energy of the reaction gas of TiCl₄ and NH₃ when forming a TiN film, the deposition rate, average specific resistance, and evaluation results of the specific resistance change compared with the non-use case in Comparative Example 1 are shown in Table 4 below.

[0230] Table 4 # TiN Process @ 550 °C Chemical Structural Formula Bond Dissociation Energy GPC (Å / cycle) Average Ratio Specific Resistance (μΩ·cm) Specific Resistance Change Relative to Non-Use of Catalyst 1 Non-Use Catalyst 0.38 200 2 I-7 236.38 0.57 113 Specific Resistance Improvement 3 I-8 239.29 0.58 117 Specific resistance improvement 4 I-12 HI 314.18 0.72 112 Specific resistance improvement 5 I-10 194.21 0.65 110 Specific resistance improvement 6 I-3 250.8 0.6 574 Specific resistance deterioration 7 I-5 244.65 0.53 392 Specific resistance deterioration 8 I-1 250.15 0.33 752 Specific resistance deterioration

[0231] As shown in Table 4 above, it can be confirmed that as the bond dissociation energy of carbon and iodine increases, the degree of specific resistance deterioration increases.

[0232] Final confirmation. When providing an ultra-thin film with a barrier material and / or a high dielectric constant material, it includes a modification step of depositing a precursor material with a specific bond dissociation energy by using a specified modified gas. Together with the initial film formation rate, it simultaneously improves film densification and film uniformity, etc., so that during etching evaluation, no pinholes are generated and the inflow of thin film impurities caused by ligands such as carbon is prevented and avoided, while being suitable for improving film quality such as electrical characteristics and crystallinity.

[0233] None

[0234] None

Claims

1. An ultrathin film, comprising a thin film formed on a substrate using one or more materials selected from barrier materials and high dielectric materials; said thin film being selected from one or more of titanium nitride film, tantalum nitride film, ruthenium film, aluminum oxide film, calcium oxide film, yttrium oxide film, strontium oxide film, zirconium oxide film, hafnium oxide film, tantalum nitride film, lanthanum oxide film, barium oxide film, and titanium oxide film; said thin film having a thickness of 10 nm or less, said thickness being measured using TEM; and said thin film having a root mean square surface roughness of 0.3 nm or less; wherein, After the film is immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, the maximum etch height of the film from top to bottom (the side closest to the substrate), as measured by scanning probe microscopy (Atomic Force Microscope, AFM), is less than 50% by etching evaluation; or after the film is immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, the maximum etch height of the film from top to bottom (the side closest to the substrate), as measured by scanning probe microscopy (Atomic Force Microscope, AFM), is less than 1.5 nm by etching evaluation.

2. An ultrathin film, comprising a thin film formed on a substrate using one or more materials selected from barrier materials and high dielectric materials; said thin film being selected from one or more of titanium nitride film, tantalum nitride film, ruthenium film, aluminum oxide film, calcium oxide film, yttrium oxide film, strontium oxide film, zirconium oxide film, hafnium oxide film, tantalum nitride film, lanthanum oxide film, barium oxide film, and titanium oxide film; said thin film having a thickness of 5 nm or less, said thickness being measured using TEM; and said deposition rate is increased by more than 30% by using a modified gas; wherein, After the film is immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, the maximum etch height of the film from top to bottom (the side closest to the substrate), as measured by scanning probe microscopy (Atomic Force Microscope, AFM), is less than 50% by etching evaluation; or after the film is immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, the maximum etch height of the film from top to bottom (the side closest to the substrate), as measured by scanning probe microscopy (Atomic Force Microscope, AFM), is less than 1.5 nm by etching evaluation.

3. The ultrathin film as described in claim 1 or 2, wherein, After the film was immersed in hydrofluoric acid (HF, 1% dilution) for 5 minutes, the surface roughness measured by scanning probe microscopy (atomic force microscopy (AFM)) was less than 0.3 nm.

4. A method for forming an ultrathin film, wherein, The ultrathin film formation method includes: an adsorption step, in which an adsorbent material is formed on a substrate by spraying a source gas composed of one or more materials selected from barrier materials and high dielectric materials; a modification step, in which the adsorbent material formed on the substrate is modified by spraying a modification gas that reacts with the source gas; and a deposition step, in which a thin film composed of one or more materials selected from barrier materials and high dielectric materials is deposited on the substrate by spraying a reaction gas that reacts with the modification gas; when the adsorption step, the modification step, and the deposition step are considered as a cycle, the ultrathin film simultaneously satisfies the following conditions: the thickness of the film formed after 10 cycles is less than 10 angstroms, and the thickness of the film formed after 20 cycles is less than 20 angstroms; the thin film is selected from one or more of titanium nitride film, tantalum nitride film, ruthenium film, aluminum oxide film, calcium oxide film, yttrium oxide film, strontium oxide film, zirconium oxide film, hafnium oxide film, tantalum nitride film, lanthanum oxide film, barium oxide film, and titanium oxide film. The modified gas includes materials with direct bonds between hydrogen (H) and iodine, materials with direct bonds between carbon (C) and iodine, or materials with direct bonds between halogens (F, Cl, Br) and iodine; the materials with direct bonds between hydrogen (H) and iodine have an overall binding energy of 305 kJ / mol to 325 kJ / mol calculated using the Gaussian 16 formula (DFT-D3 / B3LYP basis set (iodine: LanL2DZ, carbon, hydrogen: 6-31+G(dp))); the materials with direct bonds between carbon (C) and iodine have an overall binding energy of 165 kJ / mol to 242 kJ / mol calculated using the Gaussian 16 formula (DFT-D3 / B3LYP basis set (iodine: LanL2DZ, carbon, hydrogen: 6-31+G(dp))). The material exhibits a tertiary structure and has direct bonds between halogens (F, Cl, Br) and iodine, with an overall binding energy of 50 kJ / mol to 160 kJ / mol calculated using the Gaussian 16 formula (DFT-D3 / B3LYP basis set (iodine: LanL2DZ, carbon and hydrogen: 6-31+G(dp))).

5. A method for forming an ultrathin film, wherein, The ultrathin film formation method includes: a modification step, wherein the surface is modified by spraying a modifying gas onto the surface of a substrate and performing an adsorption reaction with a source gas on the substrate; an adsorption step, wherein an adsorbent material is formed on the substrate by spraying the source gas, which is composed of one or more materials selected from barrier materials and high dielectric materials; and a deposition step, wherein a thin film composed of one or more materials selected from barrier materials and high dielectric materials is deposited on the substrate by spraying a reactive gas that reacts with the source gas; when the modification step, the adsorption step, and the deposition step are considered as a cycle, the ultrathin film simultaneously satisfies the following conditions: the thickness of the film formed after repeating 10 cycles is less than 10 angstroms, and the thickness of the film formed after repeating 20 cycles is less than 20 angstroms; the thin film is selected from one or more of titanium nitride film, tantalum nitride film, ruthenium film, aluminum oxide film, calcium oxide film, yttrium oxide film, strontium oxide film, zirconium oxide film, hafnium oxide film, tantalum nitride film, lanthanum oxide film, barium oxide film, and titanium oxide film. The modified gas includes materials with direct bonds between hydrogen (H) and iodine, materials with direct bonds between carbon (C) and iodine, or materials with direct bonds between halogens (F, Cl, Br) and iodine; the materials with direct bonds between hydrogen (H) and iodine have an overall binding energy of 305 kJ / mol to 325 kJ / mol calculated using the Gaussian 16 formula (DFT-D3 / B3LYP basis set (iodine: LanL2DZ, carbon, hydrogen: 6-31+G(dp))); the materials with direct bonds between carbon (C) and iodine have an overall binding energy of 165 kJ / mol to 242 kJ / mol calculated using the Gaussian 16 formula (DFT-D3 / B3LYP basis set (iodine: LanL2DZ, carbon, hydrogen: 6-31+G(dp))). The material exhibits a tertiary structure and has direct bonds between halogens (F, Cl, Br) and iodine, with an overall binding energy of 50 kJ / mol to 160 kJ / mol calculated using the Gaussian 16 formula (DFT-D3 / B3LYP basis set (iodine: LanL2DZ, carbon and hydrogen: 6-31+G(dp))).

6. The method for forming an ultrathin film as described in claim 4 or 5, wherein, In the adsorption step, the source gas is selected from one or more of titanium, tantalum, aluminum, ruthenium, niobium, bismuth, calcium, yttrium, strontium, zirconium, hafnium, lanthanum, and barium.

7. The method for forming an ultrathin film as described in claim 4 or 5, wherein, In the modification step, a halogen gas containing iodine and having a weight-average molecular weight of 127 g / mol to 250 g / mol is sprayed onto the substrate as the modification gas.

8. The method for forming an ultrathin film as described in claim 4 or 5, wherein, In the deposition step, ozone, oxygen, nitrogen, or ammonia is sprayed onto the substrate as the reactive gas.

9. The method for forming an ultrathin film as described in claim 4 or 5, wherein, The ultrathin film formation method includes: a first purging step, in which a purging gas is sprayed onto the substrate after the adsorption step; a second purging step, in which a purging gas is sprayed onto the substrate after the modification step; and a third purging step, in which a purging gas is sprayed onto the substrate after the deposition step.

10. A semiconductor substrate, wherein, The semiconductor substrate includes an ultrathin film as described in claim 1 or 2.

11. A semiconductor device, wherein, The semiconductor device includes a semiconductor substrate as described in claim 10.

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