Step coverage improving agent, thin film forming method using the same, and semiconductor substrate and semiconductor device manufactured by the same

Abstract

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

Description

[Technical field]

[0001] The present invention relates to a step coverage improver, a method for forming a thin film using the same, and a semiconductor substrate and a semiconductor device manufactured thereby. More specifically, the present invention relates to a step coverage improver that provides a compound of a predetermined structure, and forms a deposition layer of a uniform thickness on a substrate as a shielding region due to differences in the adsorption distribution of the compound, thereby reducing the deposition rate of the thin film and appropriately lowering the thin film growth rate, thereby significantly improving step coverage and thin film thickness uniformity even when a thin film is formed on a substrate having a complex structure, and significantly reducing impurities, a method for forming a thin film using the same, and a semiconductor substrate manufactured thereby. [Background technology]

[0002] As memory and non-memory semiconductor devices continue to increase in density, substrate topologies are becoming increasingly complex.

[0003] As one example, the ratio of width to depth of a microstructure (hereinafter also referred to as the "aspect ratio") is becoming greater than 20:1 and greater than 100:1, and the larger the aspect ratio becomes, the more difficult it becomes to form a deposition layer of uniform thickness along the complex microstructure surface.

[0004] As a result, step coverage, which limits the thickness ratio of the deposition layer formed on the top and bottom of the microstructure in the depth direction, remains at a level of 90%, and the importance of this is increasing as it becomes increasingly difficult to express the electrical characteristics of the device. Since 100% step coverage means that the thickness of the deposition layer formed on the top and bottom of the microstructure is the same, it is necessary to develop technology that can achieve step coverage as close to 100% as possible.

[0005] In order for the thin film deposited on the substrate to have good and uniform physical properties, it is essential that the thin film has high step coverage. Therefore, the atomic layer deposition (ALD) process, which utilizes surface reactions, is more widely used than the chemical vapor deposition (CVD) process, which mainly utilizes gas phase reactions. However, there are still problems in achieving 100% step coverage.

[0006] When the deposition temperature is increased in order to achieve 100% step coverage, difficulties arise in terms of step coverage. First, in a deposition process that involves two types of material, a precursor and a reactant, an increase in deposition temperature not only leads to a steep increase in the growth rate of the thin film (GPC: Growth Per Cycle), but also, even if an ALD process is performed at 300°C in order to mitigate the increase in GPC caused by an increase in deposition temperature, the deposition temperature increases during the process, making it difficult to say that this is a solution.

[0007] In addition, high-temperature processes are required to realize metal oxide films with excellent film quality in semiconductor devices. Research results have been reported that increasing the deposition temperature of atomic layers to 400°C reduces the concentration of carbon and hydrogen remaining in the thin film (see the paper in J.Vac.Sci.Technol.A,35(2017)01B130).

[0008] However, the higher the deposition temperature, the more difficult it becomes to ensure the step coverage. First, in a deposition process that involves two types of materials, a precursor and a reactant, an increase in deposition temperature may lead to a steep increase in the thin film growth rate (GPC: Growth Per Cycle). In addition, even if a known shielding agent is used to mitigate the increase in GPC caused by an increase in deposition temperature, it has been confirmed that the GPC increases by about 10% at 300°C. In other words, when deposition is performed at 360°C or higher, it becomes difficult to expect the GPC reduction effect provided by conventionally known shielding agents.

[0009] Therefore, there is a demand for a thin film formation method that can effectively form thin films with complex structures even at high temperatures, with a small amount of residual impurities, and significantly improves step coverage and thin film thickness uniformity, as well as semiconductor substrates and the like manufactured thereby. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made to solve the problems of the prior art described above, and aims to provide a step coverage improver that forms a deposition layer of uniform thickness on a substrate as a shielding region for a thin film due to differences in the degree of adsorption distribution of a step coverage improver, thereby reducing the deposition rate of the thin film and appropriately lowering the thin film growth rate, thereby significantly improving step coverage and thin film thickness uniformity even when a thin film is formed on a substrate having a complex structure, a thin film formation method using the same, and a semiconductor substrate manufactured thereby.

[0011] The present invention aims to improve the crystallinity and oxidation fraction of a thin film, thereby improving the density, electrical properties, and dielectric properties of the thin film.

[0012] The above and other objects of the present invention can be achieved by the present invention described below. [Means for solving the problem]

[0013] In order to achieve the above object, the present invention provides a step coverage improving agent comprising a compound represented by the following Chemical Formula 1:

[0014] chemical formula 1

[0015] [ka]

[0016] (In the above Chemical Formula 1, R 1and R 2 are each independently H or an alkyl group having 1 to 5 carbon atoms, and n is an integer of 2 to 4.

[0017] The step coverage improving agent may include one or more compounds selected from the compounds represented by the following chemical formulas 1-1 to 1-6.

[0018] Chemical formula 1-1~1-6

[0019] [ka]

[0020] The step coverage improving agent may have a deposition rate reduction rate, represented by the following Equation 1, of 30% or more.

[0021] Formula 1

[0022]

number

[0023] (In the above formula, DR (Deposition rate, Å / cycle) is the rate at which a thin film is deposited. When a thin film is deposited by a precursor and a reactant, DR i (initial deposition rate) is the deposition rate of the thin film formed without adding a step coverage improving agent. DR f (final deposition rate) is the deposition rate of the thin film formed by adding a step coverage improving agent when carrying out the above-mentioned process. Here, the deposition rate (DR) is a value measured by an ellipsometer device under conditions of room temperature and normal pressure for a thin film having a thickness of 3 to 30 nm, and is expressed in Å / cycle units.)

[0024] The step coverage improving agent may have a refractive index of 1.38 or more, 1.38 to 1.5, 1.38 to 1.45, or 1.39 to 1.44.

[0025] The step coverage improver may provide a shielding region for an oxide film, a nitride film, a metal film, or selectively thin films thereof.

[0026] The shielding region may be formed on the entire substrate or a portion of the substrate on which the oxide film, nitride film, metal film, or selective thin film thereof is formed.

[0027] When the total area of ​​the entire or partial substrate (total area of ​​the substrate) is taken as 100%, the shielded area may occupy 10 to 95% of the area, and the unshielded area may occupy the remaining area.

[0028] When the total area of ​​the entire substrate or part of the substrate (total area of ​​the substrate) is 100%, the first shielded area may occupy 10 to 95% of the area, the second shielded area may occupy 10 to 95% of the remaining area, and the unshielded area may occupy the remaining area.

[0029] The thin film can improve step coverage in the process of forming a laminated film of one or more elements selected from the group consisting of Al, Si, Ti, V, Co, Ni, Cu, Zn, Ga, Ge, Se, Zr, Nb, Mo, Ru, Rh, In, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, La, Ce, and Nd.

[0030] The thin film can 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, and can improve step coverage during its formation.

[0031]

[0032] The present invention also provides a method for forming a thin film, comprising the step of injecting a step coverage improving agent represented by the following Chemical Formula 1 into a chamber to shield a surface of a loaded substrate:

[0033] chemical formula 1

[0034] [ka]

[0035] (In the above Chemical Formula 1, R 1 and R 2 are each independently H or an alkyl group having 1 to 5 carbon atoms, and n is an integer of 2 to 4.

[0036] The precursor compound used in the thin film formation method may be a compound represented by the following Chemical Formula 2.

[0037] chemical formula 2

[0038] [ka]

[0039] (In the above formula 2, M is at least one selected from Al, Si, Ti, V, Co, Ni, Cu, Zn, Ga, Ge, Se, Zr, Nb, Mo, Ru, Rh, In, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, La, Ce, and Nd; L 1 , L 2 , L 3 , and L 4 -H, -X, -R, -OR, -NR 2 or Cp (cyclopentadiene), which may be the same or different, where -X is F, Cl, Br or I, and -R is C1-C 10 Alkyl, C1-C 10 Alkenes, or C1-C 10 which may be linear or cyclic, 1 , L 2 , L 3 and L 4 can be formed from 2 to 6 depending on the oxidation value of the central metal (M).

[0040] As an example, when the central metal is divalent, L 1 and L 2can be attached to the central metal as a ligand, and if the central metal is hexavalent, L 1 , L 2 , L 3 , L 4 , L 5 , L 6 can be attached to the central metal, and L 1 ~L 6 The ligands corresponding to may be the same or different from each other.

[0041] In the above formula 2, L 1 , L 2 , L 3 and L 4 is -H or -R, which may be the same or different, and where -R is C1 to C 10 Alkyl, C1-C 10 Alkenes, or C1-C 10 and may be linear or cyclic.

[0042] In the above formula 2, L 1 , L 2 , L 3 and L 4 -H, -OR, -NR 2 or Cp (cyclopentadiene), which may be the same or different, where -R is H, C1-C 10 Alkyl, C1-C 10 Alkenes, C1-C 10 alkane, iPr, or TBu.

[0043] In the above Chemical Formula 2, L 1 , L 2 , L 3 and L 4 may be the same or different as -H, or -X, where -X can be F, Cl, Br or I.

[0044]

[0045] The present invention also relates to

[0046] i) vaporizing the step coverage improving agent to form a shielding region on a surface of a substrate loaded into a chamber;

[0047] ii) initially purging the interior of the chamber with a purge gas;

[0048] iii) vaporizing a precursor compound and allowing it to adsorb in an area outside the shielded area;

[0049] iv) second purging the interior of the chamber with a purge gas;

[0050] v) supplying a reaction gas into the chamber;

[0051] vi) a third step of purging the inside of the chamber with a purge gas.

[0052] The precursor compound may be a precursor that is a molecule consisting of one or more species selected from the group consisting of Al, Si, Ti, V, Co, Ni, Cu, Zn, Ga, Ge, Se, Zr, Nb, Mo, Ru, Rh, In, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, La, Ce, and Nd, and has a vapor pressure at 25°C of more than 0.01 mTorr and not more than 100 Torr.

[0053] The chamber may be an atomic layer deposition (ALD) chamber, a chemical vapor deposition (CVD) chamber, a plasma enhanced atomic layer deposition (PEALD) chamber, or a plasma enhanced chemical vapor deposition (PECVD) chamber.

[0054] After the step coverage improving agent or precursor compound is vaporized and injected, a plasma post-treatment step may be included.

[0055] The amount of the purge gas introduced into the chamber in each of the steps i) and iv) may be 10 to 100,000 times the volume of the introduced step coverage improving agent.

[0056] The reaction gas may be an oxidizing agent, a nitriding agent, or a reducing agent, and the reaction gas, the step coverage improving agent, and the precursor compound may be delivered into the chamber by a vapor flow control (VFC) method, a direct liquid introduction (DLI) method, or a liquid delivery system (LDS) method.

[0057] The thin film may be a silicon nitride film, a silicon oxide film, a titanium nitride film, a titanium oxide film, a tungsten nitride film, a molybdenum nitride film, a hafnium oxide film, a zirconium oxide film, a tungsten oxide film, or an aluminum oxide film.

[0058] The substrate loaded into the chamber is heated to 100 to 800° C., and the ratio of the amount (mg / cycle) of the step coverage improving agent to the precursor compound input into the chamber may be 1:1 to 1:20.

[0059]

[0060] The present invention also provides a semiconductor substrate comprising a thin film produced by the above-mentioned thin film formation method.

[0061] The thin film may have a multi-layer structure of two or more layers.

[0062]

[0063] The present invention also provides a semiconductor device including the semiconductor substrate described above.

[0064] The semiconductor substrate can be low resistive metal gate interconnects, high aspect ratio 3D metal-insulator-metal (MIM) capacitors, DRAM trench capacitors, 3D Gate-All-Around (GAA), or 3D NAND flash memory. Effect of the Invention

[0065] According to the present invention, it is possible to provide a step coverage improving agent that effectively blocks adsorption to the substrate surface, improves the reaction rate, appropriately reduces the thin film growth rate, and improves step coverage even when a thin film is formed on a substrate having a complex structure.

[0066] In addition, the process by-products during the formation of the thin film are more effectively reduced, corrosion and deterioration are prevented, and the film quality is modified to improve the crystallinity of the thin film, thereby improving the electrical characteristics of the thin film.

[0067] In addition, the amount of process by-products during thin film formation can be reduced, and the step coverage and density of the thin film can be improved. Furthermore, a thin film formation method using the same and a semiconductor substrate manufactured thereby can be provided. [Brief description of the drawings]

[0068] [Figure 1] FIG. 2 is a diagram illustrating a deposition process sequence according to the present invention, focusing on one cycle.

[0069] [Diagram 2] FIG. 1 is a diagram showing the results of SIMC C analysis measured in Example 1 according to the present invention and Comparative Examples 1, 3, and 4.

[0070] [Diagram 3] TEM photographs showing the film thicknesses deposited at the upper (100 nm below the top) and lower (100 nm above the bottom) cross-sections of an oxide film deposited without using a step coverage improving agent according to Comparative Example 1, and the film thicknesses deposited at the upper (100 nm below the top) and lower (100 nm above the bottom) cross-sections of an oxide film deposited with a step coverage improving agent.

[0071] [Figure 4] FIG. 1 shows TEM photographs of the film thicknesses deposited at the top (100 nm below the top) and bottom (100 nm above the bottom) of a cross section of an oxide film deposited using a step coverage improving agent according to Example 1, and the film thicknesses deposited at the top (100 nm below the top) and bottom (100 nm above the bottom) of a cross section of an oxide film deposited using a step coverage improving agent. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0072] The above-described step coverage improving agent, a thin film forming method using the same, and a semiconductor substrate manufactured thereby will be described in detail below.

[0073] In this description, unless otherwise specified, the term "step coverage improving agent" means not only reducing, preventing or blocking the adsorption of a precursor compound for forming a thin film onto a substrate, but also reducing, preventing or blocking the adsorption of process by-products onto a substrate, thereby improving step coverage.

[0074] The present inventors have found that a compound having a specific structure is provided as a step coverage improver for a deposition film formed on a substrate loaded inside a chamber, and a deposition layer of a uniform thickness due to the difference in the adsorption distribution degree of the compound is formed as a shielding region that does not remain in the thin film, forming a relatively sparse thin film, and the growth rate of the formed thin film is significantly reduced, so that even if applied to a substrate with a complex structure at high temperature, the uniformity of the thin film is ensured and the step coverage is significantly improved, and in particular, it is possible to deposit a thin film, and it is possible to improve O, Si, metal, metal oxide, and even the carbon residue that was difficult to reduce in the past that remain as process by-products. Based on this finding, the present invention has been completed by incorporating the findings into research on step coverage improvers.

[0075]

[0076] The thin film may be provided as one or more precursors selected from the group consisting of, for example, Al, Si, Ti, V, Co, Ni, Cu, Zn, Ga, Ge, Se, Zr, Nb, Mo, Ru, Rh, In, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, La, Ce, and Nd, and may improve the step coverage of an oxide film, a nitride film, or a metal film. In this case, the effect to be achieved in the present invention may be sufficiently obtained.

[0077] Specific examples of the thin film include a silicon nitride film, a silicon oxide film, a titanium nitride film, a titanium oxide film, a tungsten nitride film, a molybdenum nitride film, a hafnium oxide film, a zirconium oxide film, a tungsten oxide film, and an aluminum oxide film.

[0078] The thin film may contain the above-mentioned film compositions alone or as selective areas, but is not limited thereto, and is meant to include SiH and SiOH.

[0079] The thin film can be used in semiconductor devices by improving step coverage during the formation process, 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 block oxide film, or a charge trap.

[0080]

[0081] In the present invention, the precursor compound used to form a thin film is a molecule having Al, Si, Ti, V, Co, Ni, Cu, Zn, Ga, Ge, Se, Zr, Nb, Mo, Ru, Rh, In, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, La, Ce, or Nd as a central metal atom (M) and one or more ligands consisting of C, N, O, H, or X (halogens), and in the case of a precursor having a vapor pressure of 1 mTorr to 100 Torr at 25° C., the effect of being shielded by a step coverage improving agent described below can be maximized.

[0082] As an example of the precursor compound, a compound represented by the following Chemical Formula 2 can be used.

[0083] chemical formula 2

[0084] [ka]

[0085] (In the above formula 2, M is at least one selected from Al, Si, Ti, V, Co, Ni, Cu, Zn, Ga, Ge, Se, Zr, Nb, Mo, Ru, Rh, In, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, La, Ce, and Nd; L 1 , L 2 , L 3 , and L 4 -H, -X, -R, -OR, -NR 2 or Cp (cyclopentadiene), which may be the same or different, where -X is F, Cl, Br or I, and -R is C1-C 10 Alkyl, C1-C10 Alkenes, or C1-C 10 which may be linear or cyclic, and the ligand L 1 , L 2 , L 3 and L 4 can be formed into 2 to 6 depending on the degree of oxidation of the central metal.)

[0086] As an example, when the central metal is divalent, L 1 and L 2 can be attached to the central metal as a ligand, and if the central metal is hexavalent, L 1 , L 2 , L 3 , L 4 , L 5 , L 6 can be attached to the central metal, and L 1 ~L 6 The ligands corresponding to may be the same or different from each other.

[0087] In the formula 2, M is hafnium (Hf), silicon (Si), zirconium (Zr) or aluminum (Al), preferably hafnium (Hf) or silicon (Si). In this case, there are advantages in that the effect of reducing process by-products is large, the step coverage is excellent, the effect of improving the thin film density, and the electrical properties, insulation and dielectric properties of the thin film are further excellent.

[0088] Said L 1 , L 2 , L 3 and L 4 is -H or -R, which may be the same or different, and where -R is C1 to C 10 Alkyl, C1-C 10 Alkenes, or C1-C 10 and may have a linear or cyclic structure.

[0089] In addition, the above-mentioned L 1 , L 2 , L 3 and L 4are -H, -OR, -NR2, or Cp (cyclopentadiene), which may be the same or different, where -R is H, C1 to C 10 Alkyl, C1-C 10 Alkenes, C1-C 10 alkane, iPr, or tBu.

[0090] In addition, in the above-mentioned chemical formula 2, L 1 , L 2 , L 3 and L 4 may be the same or different from each other as -H, or -X, where -X can be F, Cl, Br, or I.

[0091] Specifically, examples of hafnium precursor compounds that can be used include tris(dimethylamido)cyclopentadienylhafnium, CpHf(NMe2)3, and (methyl-3-cyclopentadienylpropylamino)bis(dimethylamino)hafnium, Cp(CH2)3NM3Hf(NMe2)2.

[0092] Examples of silicon precursor compounds include SiH4, SiHCl3, SiH2Cl2, SiCl4, Si2Cl6, Si3Cl8, and Si4Cl. 10 , SiH2[NH(C4H9)]2, Si2(NHC2H5)4, Si3NH4(CH3)3, and one or more selected from SiH3[N(CH3)2], SiH2[N(CH3)2]2, SiH[N(CH3)2]3, and Si[N(CH3)2]4 can be used.

[0093] Moreover, examples of titanium precursor compounds that can be used include TiCl4 (Titanium tetrachloride), TDMAT (tetrakisDimethylamino Titanium), and Ti(CpMe5)(OMe)3.

[0094]

[0095] The step coverage improving agent of the present invention has a long chain structure and is adsorbed on the surface of the substrate prior to the adsorption of the precursor compound to be adsorbed on the substrate, thereby realizing uniform adsorption of the precursor compound on the substrate. That is, it is preferable to use a compound that can provide a region that blocks the adsorption of the precursor compound adsorbed on the substrate (hereinafter, also referred to as a "shielding region").

[0096] For example, the shielding region may be formed on the entire substrate or a portion of the substrate on which the thin film is formed.

[0097] Furthermore, when the total area of ​​the entire substrate or a portion of the substrate (total area of ​​the substrate) is taken as 100%, the shielded region may occupy, for example, 10 to 95% of the area, specifically 15 to 90% of the area, preferably 20 to 85% of the area, more preferably 30 to 80% of the area, even more preferably 40 to 75% of the area, and even more preferably 40 to 70% of the area, and the unshielded region may occupy the remaining area.

[0098] Furthermore, when the total area of ​​the entire substrate or a portion of the substrate (the entire area of ​​the substrate) is taken as 100%, the first shielded region may occupy an area of ​​10 to 95%, specifically 15 to 90%, preferably 20 to 85%, more preferably 30 to 80%, even more preferably 40 to 75%, and even more preferably 40 to 70% of the remaining area, the second shielded region may occupy an area of ​​10 to 95%, specifically 15 to 90%, preferably 20 to 85%, more preferably 30 to 80%, even more preferably 40 to 75%, and even more preferably 40 to 70% of the remaining area, and the remaining area may be occupied by an unshielded region.

[0099]

[0100] The step coverage improving agent can provide the above-mentioned shielding region on the surface of the substrate on which the above-mentioned thin film is provided.

[0101] The step coverage improving agent may include a linear or cyclic saturated or unsaturated hydrocarbon having 3 to 15 carbon atoms and having two or more nitrogen (N), oxygen (O), phosphorus (P) or sulfur (S). In this case, when forming a thin film, a shielding region that does not remain in the thin film is formed to form a relatively sparse thin film, and side reactions are suppressed and the thin film growth rate is controlled to reduce process by-products in the thin film, thereby reducing corrosion and deterioration, improving the crystallinity of the thin film, and allowing a stoichiometric oxidation state to be reached when a metal oxide film is formed. Thus, even when a thin film is formed on a substrate having a complex structure, there are effects of significantly improving step coverage and thin film thickness uniformity.

[0102] As a specific example, the step coverage improver has a structure containing nitrogen (N), oxygen (O), phosphorus (P) or sulfur (S) at both ends of a central carbon atom connected to oxygen by a double bond, and thus has a large effect of reducing process by-products and excellent step coverage, as well as an effect of improving thin film density and excellent electrical properties of the thin film.

[0103] The step coverage improver may be one or more selected from compounds represented by the following formula 1, for example. In this case, when forming a thin film, a shielding region that does not remain in the thin film is formed to form a relatively sparse thin film, and side reactions are suppressed and the thin film growth rate is controlled to reduce process by-products in the thin film, thereby reducing corrosion and deterioration, and the crystallinity of the thin film is improved. Even when a thin film is formed on a substrate having a complex structure, the step coverage and the thickness uniformity of the thin film can be significantly improved.

[0104] chemical formula 1

[0105] [ka]

[0106] (In the above Chemical Formula 1, R 1 and R 2are each independently H or an alkyl group having 1 to 5 carbon atoms, and n is an integer of 2 to 4.

[0107] In the above Chemical Formula 1, R 1 and R 2 is an alkyl group having 1 to 5 carbon atoms, and preferably an alkyl group having 2 to 4 carbon atoms. In this case, there are advantages such as a large effect of reducing process by-products and excellent step coverage, as well as an effect of improving the thin film density and further excellent electrical properties, insulating properties, and dielectric properties of the thin film.

[0108] In the above Chemical Formula 1, n is an integer of 2 to 4, preferably an integer of 2 to 3. In this case, there are advantages in that the effect of reducing process by-products is large, the step coverage is excellent, the thin film density is improved, and the electrical properties, insulating properties, and dielectric properties of the thin film are further excellent.

[0109]

[0110] The step coverage improver, preferably the compound represented by Chemical Formula 1, may have a deposition rate reduction rate represented by the following Formula 1 of 30% or more, specifically 33% or more, preferably 35% or more. In this case, the step coverage improver having the above structure forms a shielding region that does not remain in the thin film to form a relatively sparse thin film, and the growth rate of the thin film formed is significantly reduced. Therefore, even if the thin film is applied to a substrate having a complex structure under high temperature, the uniformity of the thin film is ensured and the step coverage is significantly improved. In particular, the thin film can be deposited at a thin thickness, and the amount of O, Si, metal, metal oxide, and even the amount of carbon remaining as process by-products, which was previously difficult to reduce, can be improved.

[0111] Formula 1

[0112]

number

[0113] (In the above formula, DRn is a depth rate measured for a thin film manufactured without adding the step coverage improving agent, and DRw is a depth rate measured for a thin film manufactured with adding the step coverage improving agent, where the depth rate is a value measured for a thin film having a thickness of 3 to 30 nm under conditions of room temperature and pressure using an ellipsometer device, and is expressed in Å / cycle units.)

[0114] In Equation 1, the thin film growth rate per cycle when the step coverage improving agent is used and when the step coverage improving agent is not used means the deposition thickness (Å / cycle) of the thin film per cycle, i.e., the deposition rate. For example, the deposition rate can be calculated by measuring the final thickness of a thin film having a thickness of 3 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.

[0115] In the above formula 1, "when no step coverage improving agent was used" refers to a case where a thin film is manufactured by adsorbing only a precursor compound onto a substrate in a thin film deposition process. A specific example of the thin film formation method is a case where a thin film is formed by omitting the step of adsorbing a step coverage improving agent and the step of purging unadsorbed step coverage improving agent.

[0116]

[0117] The step coverage improving agent can be, for example, a compound having a refractive index of 1.38 or more, specifically, within the range of 1.38 to 1.5, or 1.38 to 1.45, and preferably 1.39 to 1.44.

[0118] In this case, the step coverage improving agent having the above-mentioned structure on the substrate forms a shielding region where it does not remain in the thin film, thereby reducing the deposition rate of the thin film and appropriately reducing the thin film growth rate, thereby significantly improving step coverage and thin film thickness uniformity even when a thin film is formed on a substrate having a complex structure, and effectively protecting the surface of the substrate by preventing the adsorption of not only the thin film precursor but also the process by-products, and effectively removing the process by-products.

[0119] In particular, since a relatively sparse thin film is formed and the growth rate of the formed thin film is significantly reduced, even if the thin film is applied to a substrate having a complex structure at high temperature, the uniformity of the thin film is ensured and the step coverage is significantly improved. In particular, the method can provide an effect of improving O, Si, metal, metal oxide, and even carbon residues that are remaining as process by-products and that have been difficult to reduce in the past, since the method can deposit a thin thin film.

[0120]

[0121] The compound represented by Chemical Formula 1 may include compounds represented by Chemical Formulas 1-1 to 1-6. In this case, a deposition layer of uniform thickness due to the difference in adsorption distribution on a substrate is provided as a shielding region on the substrate, which has a large effect of controlling the growth rate of a thin film, and has a large effect of removing process by-products, as well as an excellent effect of improving step coverage and film quality.

[0122] Chemical formula 1-1~1-6

[0123] [ka]

[0124] The step coverage improver can provide a shielding region for the thin film.

[0125] The thin film shielding region is characterized in that it does not remain on the thin film.

[0126] Here, unless otherwise specified, "not remaining" refers to the presence of C element at 0.1 atomic % (atom %), Si element at less than 0.1 atomic % (atom %), N element at less than 0.1 atomic % (atom %), and halogen element at less than 0.1 atomic % (atom %) in a component analysis by X-ray photoelectron spectroscopy (XPS). More preferably, in a measurement method by secondary ion mass spectrometry (SIMS) in which measurements are made while digging into the substrate in the depth direction, or a measurement method by X-ray photoelectron spectroscopy (XPS), when considering the increase / decrease rates of C, N, Si, and halogen impurities before and after using a step coverage improving agent under the same deposition conditions, it is preferable that the increase / decrease rate of the signal sensitivity (intensity) of each element type does not exceed 5%.

[0127]

[0128] As an example, the thin film may contain halogen compounds at 100 ppm or less.

[0129] The thin film can be used as an etching stop film, an electrode film, a dielectric film, a gate insulating film, a block oxide film, or a charge trap, but is not limited to these.

[0130] The step coverage improver may be a compound having a purity of 99.9% or more, a compound having a purity of 99.95% or more, or a compound having a purity of 99.99% or more. For reference, when a compound having a purity of less than 99% is used, impurities may remain in the thin film or cause a side reaction with the precursor or reactant, so it is preferable to use a substance having a purity of 99% or more.

[0131]

[0132] The step coverage improver is preferably used in an atomic layer deposition (ALD) process, and in this case, has the advantages of effectively protecting the surface of a substrate as a step coverage improver without interfering with the adsorption of a precursor compound, and effectively removing process by-products.

[0133] The step coverage improving agent is preferably a liquid at room temperature (22° C.) and has a density of 0.8 to 2.5 g / cm 3 or 0.8~1.5g / cm 3 The vapor pressure (20° C.) may be 0.1 to 300 mmHg or 1 to 300 mmHg. Within this range, the shielding region is effectively formed, and there is an effect of excellent step coverage, thin film thickness uniformity, and improved film quality.

[0134] More preferably, the step coverage improving agent has a density of 0.75 to 2.0 g / cm 3 or 0.8~1.3g / cm 3 The vapor pressure (20° C.) can be 1 to 260 mmHg. Within this range, the shielding region is effectively formed, and there is an effect that the step coverage, the thin film thickness uniformity, and the improvement of the film quality are excellent.

[0135]

[0136] The method for forming a thin film of the present invention is characterized by including a shielding step of injecting a step coverage improving agent represented by the following chemical formula 1 into a chamber to shield the surface of a loaded substrate. In this case, a deposition layer of uniform thickness due to differences in adsorption distribution on the substrate is formed as a shielding region on the substrate, thereby reducing the deposition rate of the thin film and appropriately reducing the thin film growth rate, thereby significantly improving step coverage and thickness uniformity of the thin film even when a thin film is formed on a substrate having a complex structure.

[0137] chemical formula 1

[0138] [ka]

[0139] (In the above Chemical Formula 1, R 1 and R 2 are each independently H or an alkyl group having 1 to 5 carbon atoms, and n is an integer of 2 to 4.

[0140]

[0141] In the step of shielding the surface of the substrate with the step coverage improving agent, the feeding time (seconds [sec]) of the step coverage improving agent to the surface of the substrate is preferably 0.01 to 10 seconds per cycle, more preferably 0.02 to 8 seconds, even more preferably 0.04 to 6 seconds, and even more preferably 0.05 to 5 seconds. Within this range, there are advantages such as a low thin film growth rate and excellent step coverage and economy.

[0142] In this description, the feeding time of the precursor compound is based on a flow rate of 0.1 to 500 mg / cycle in a chamber volume of 15 to 20 L, and more specifically, based on a flow rate of 0.8 to 200 mg / cycle in a chamber volume of 18 L.

[0143] As a preferred embodiment, the thin film formation method may include the steps of i) vaporizing the step coverage improving agent to shield a surface of a substrate loaded into a chamber, ii) performing a primary purge of the interior of the chamber with a purge gas, iii) vaporizing a precursor compound to be adsorbed onto the surface of the substrate loaded into the chamber, iv) performing a secondary purge of the interior of the chamber with a purge gas, v) supplying a reaction gas into the interior of the chamber, and vi) performing a tertiary purge of the interior of the chamber with a purge gas.

[0144] In this case, steps i) to vi) are regarded as a unit cycle, and the cycle can be repeated until a thin film having a desired thickness is obtained. When the step coverage improving agent of the present invention is introduced prior to the precursor compound in one cycle and adsorbed onto the substrate, there are advantages that the thin film growth rate can be appropriately reduced even when deposition is performed at a high temperature, the generated process by-products are effectively removed, the resistivity of the thin film is reduced, and the step coverage is significantly improved.

[0145]

[0146] As a preferred example, the method for forming a thin film of the present invention may be performed by adding the step coverage improving agent of the present invention prior to the step coverage improving agent in one cycle to activate the surface of the substrate, and then adding a precursor compound to be adsorbed onto the substrate. In this case, even if the thin film is deposited at a high temperature, a deposition layer of uniform thickness due to the difference in the degree of adsorption distribution on the substrate is provided as a shielding region on the substrate, thereby appropriately reducing the thin film growth rate, thereby significantly reducing process by-products, significantly improving step coverage, increasing the formability of the thin film and reducing the resistivity of the thin film. Even if the method is applied to a semiconductor device having a large aspect ratio, the uniformity of the thin film thickness is significantly improved, thereby ensuring the reliability of the semiconductor device.

[0147]

[0148] In the thin film forming method, as an example, when the step coverage improving agent is deposited before or after the deposition of the precursor compound, a unit cycle can be repeated 1 to 99,999 times as necessary, and preferably a unit cycle can be repeated 10 to 10,000 times, more preferably 50 to 5,000 times, and further preferably 100 to 2,000 times. Within this range, the effect to be achieved in the present invention can be sufficiently obtained while obtaining a target thin film thickness.

[0149]

[0150] The precursor compound is a molecule having Al, Si, Ti, V, Co, Ni, Cu, Zn, Ga, Ge, Se, Zr, Nb, Mo, Ru, Rh, In, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, La, Ce, or Nd as a central metal atom and one or more ligands consisting of C, N, O, and H, and in the case of a precursor having a vapor pressure of 1 mTorr to 100 Torr at 25° C., the effect of forming a shielding region by the step coverage improving agent can be maximized.

[0151] The precursor compound is not particularly limited as long as it is a compound known in the art. For example, a compound containing a cyclopentadiene (Cp) group or a halogen group can be used.

[0152] Specifically, examples of hafnium precursor compounds that can be used include tris(dimethylamido)cyclopentadienylhafnium, CpHf(NMe2)3, and (methyl-3-cyclopentadienylpropylamino)bis(dimethylamino)hafnium, Cp(CH2)3NM3Hf(NMe2)2.

[0153] Examples of silicon precursor compounds include SiH4, SiHCl3, SiH2Cl2, SiCl4, Si2Cl6, Si3Cl8, and Si4Cl. 10 , SiH2[NH(C4H9)]2, Si2(NHC2H5)4, Si3NH4(CH3)3, and one or more selected from SiH3[N(CH3)2], SiH2[N(CH3)2]2, SiH[N(CH3)2]3, and Si[N(CH3)2]4 can be used.

[0154] As the titanium precursor compound, for example, TiCl4 (Titanium tetrachloride), TDMAT (tetrakisDimethylamino Titanium), Ti(CpMe5)(OMe)3, etc. can be used.

[0155]

[0156] In the present invention, the chamber may be, for example, an ALD chamber, a CVD chamber, a PEALD chamber or a PECVD chamber.

[0157] In the present invention, the step coverage improving agent or precursor compound may include a step of performing a plasma post-treatment after being vaporized and injected, in which case the growth rate of the thin film can be improved while reducing process by-products.

[0158]

[0159] When the step coverage improver is first adsorbed on the substrate and then the precursor compound is adsorbed, the amount of purge gas introduced into the chamber in the step of purging the unadsorbed step coverage improver is not particularly limited as long as it is an amount sufficient to remove the unadsorbed step coverage improver, but as an example, it may be 10 to 100,000 times, preferably 50 to 50,000 times, more preferably 100 to 10,000 times, and within this range, the unadsorbed step coverage improver is sufficiently removed to form a thin film uniformly and prevent deterioration of film quality. Here, the amounts of the purge gas and the step coverage improver introduced are each based on one cycle, and the volume of the step coverage improver means the volume of the vaporized step coverage improver vapor.

[0160] As a specific example, when the injection amount of the step coverage improvement agent is 200 sccm and the purge gas has a flow rate of 5000 sccm in the step of purging the unadsorbed step coverage improvement agent, the injection amount of the purge gas is 25 times the injection amount of the step coverage improvement agent.

[0161]

[0162] In addition, 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 as an example, it may be 10 to 10,000 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, and within this range, the unadsorbed precursor compound can be sufficiently removed to form a thin film uniformly and prevent deterioration of the film quality. Here, the amounts of the purge gas and the precursor compound introduced are each based on one cycle, and the volume of the precursor compound means the volume of the vaporized precursor compound vapor.

[0163]

[0164] 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.

[0165]

[0166] The step coverage improving agent and the precursor compound can be preferably delivered into the chamber by the VFC method, the DLI method or the LDS method, and more preferably are delivered into the chamber by the LDS method.

[0167] The substrate loaded in the chamber may be heated to, for example, 100 to 650° C., specifically, 150 to 550° C., and the step coverage improver or precursor compound may be injected onto the substrate in an unheated or heated state, and the heating conditions may be adjusted during the deposition process after being injected unheated depending on deposition efficiency. For example, the step coverage improver or precursor compound may be injected onto the substrate at 100 to 650° C. for 1 to 20 seconds.

[0168]

[0169] The ratio of the amounts (mg / cycle) of the precursor compound and the step coverage improving agent fed into the chamber may be preferably 1:1.5 to 1:20, more preferably 1:2 to 1:15, even more preferably 1:2 to 1:12, and still more preferably 1:2.5 to 1:10. Within this range, the effect of improving step coverage and the effect of reducing process by-products are large.

[0170]

[0171] In the thin film formation method, when the step coverage improving agent is used, for example, the reduction rate of the deposition rate represented by the following mathematical formula 1 may be 30% or more, specifically 33% or more, and preferably 35% or more. In this case, a deposition layer having a uniform thickness due to the difference in adsorption distribution degree of the step coverage improving agent having the above-mentioned structure is formed as a shielding region that does not remain in the thin film, thereby forming a relatively sparse thin film, and the growth rate of the formed thin film is significantly reduced. Therefore, even if the method is applied to a substrate having a complex structure under high temperature, the uniformity of the thin film is ensured and the step coverage is significantly improved. In particular, it is possible to provide an effect that the deposition can be performed on a thin thin film, and O, Si, metal, metal oxide, and even carbon residues that have remained as process by-products and have been difficult to reduce in the past can be improved.

[0172] Formula 1

[0173]

number

[0174] (In the above formula, DR (Deposition rate, Å / cycle) is the rate at which a thin film is deposited. When a thin film is deposited by a precursor and a reactant, DR i (initial deposition rate) is the deposition rate of the thin film formed without adding a step coverage improving agent. DR f (final deposition rate) is the deposition rate of the thin film formed by adding a step coverage improving agent when carrying out the above-mentioned process. Here, the deposition rate (DR) is a value measured by an ellipsometer device under conditions of room temperature and normal pressure for a thin film having a thickness of 3 to 30 nm, and is expressed in Å / cycle units.)

[0175]

[0176] In the thin film formation method, the strength (c / s) of residual carbon impurities in the thin film, based on a thin film thickness of 100 Å, measured based on SIMS, can be preferably 10,000 or less, more preferably 7,000 or less, even more preferably 5,000 or less, and even more preferably 1,000 or less. In a preferred embodiment, it can be 5,000 or less, more preferably 500 to 3,000, and even more preferably 100 to 1,000. Within this range, the effect of preventing corrosion and deterioration is outstanding.

[0177] In this description, the purge 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, and within this range, the thin film growth rate per cycle is appropriately controlled, and deposition is performed as or close to an atomic mono-layer, which is advantageous in terms of film quality.

[0178]

[0179] The ALD (atomic layer deposition) process is very advantageous in the fabrication of integrated circuits (ICs) that require high aspect ratios, and has advantages such as excellent conformality, uniformity, and precise thickness control due to its self-limiting thin film growth mechanism.

[0180] The thin film formation method can be carried out at a deposition temperature in the range of, for example, 50 to 800°C, preferably at a deposition temperature in the range of 300 to 700°C, more preferably at a deposition temperature in the range of 400 to 650°C, and further preferably at a deposition temperature in the range of 400 to 600°C. Within this range, there is an effect of growing a thin film with excellent film quality while realizing the ALD process characteristics.

[0181] The thin film formation method can be carried out, for example, at a deposition pressure in the range of 0.01 to 20 Torr, preferably at a deposition pressure in the range of 0.1 to 20 Torr, more preferably at a deposition pressure in the range of 0.1 to 10 Torr, and most preferably at a deposition pressure in the range of 0.3 to 7 Torr. Within this range, there is an effect that a thin film with a uniform thickness can be obtained.

[0182] In this description, deposition temperature and deposition pressure may be measured as the temperature and pressure established within a deposition chamber, or may be measured as the temperature and pressure applied to a substrate within the deposition chamber.

[0183] The thin film formation method may preferably include a step of raising the temperature in the chamber to a deposition temperature before introducing the step coverage improving agent into the chamber, and / or a step of injecting an inert gas into the chamber to purge the chamber before introducing the step coverage improving agent into the chamber.

[0184] The present invention may also include a thin-film manufacturing apparatus capable of implementing the thin-film manufacturing method, the thin-film manufacturing apparatus including an ALD chamber, a first vaporizer for vaporizing a step coverage improving agent, a first transport means for transporting the vaporized step coverage improving agent into the ALD chamber, a second vaporizer for vaporizing a thin-film precursor, and a second transport means for transporting the vaporized thin-film precursor into the ALD chamber. Here, the vaporizer and the transport means are not particularly limited as long as they are vaporizers and transport means commonly used in the technical field to which the present invention pertains.

[0185]

[0186] As a specific example, the method of forming the thin film will be described. First, a substrate on which a thin film is to be formed is placed in a deposition chamber capable of depositing atomic layers.

[0187] The substrate may be a semiconductor substrate such as a silicon substrate or a silicon oxide substrate.

[0188] The substrate may further have a conductive or insulating layer formed thereon.

[0189] In order to deposit a thin film on a substrate placed in the deposition chamber, the above-mentioned step coverage improving agent and a precursor compound or a mixture thereof with a non-polar solvent are prepared.

[0190] Then, the prepared step coverage improving agent is injected into a vaporizer, converted into a vapor phase, and delivered to a deposition chamber to be adsorbed onto a substrate, and then purged to remove any unadsorbed step coverage improving agent.

[0191] Next, the prepared precursor compound or a mixture of the precursor compound and a non-polar solvent (thin film forming composition) is injected into a vaporizer, converted into a vapor phase, and transferred to a deposition chamber to be adsorbed onto a substrate, and unadsorbed precursor compound / thin film forming composition is purged.

[0192] In this description, the step of adsorbing the step coverage improving agent onto a substrate and then purging to remove any unadsorbed step coverage improving agent, and the step of adsorbing a precursor compound onto a substrate and purging to remove any unadsorbed precursor compound, may be performed in a different order as necessary.

[0193] In this description, examples of a method for supplying the step coverage improving agent and the precursor compound (thin film forming composition) to the deposition chamber include a method for transporting a volatilized gas (VFC: Vapor Flow Control) using a gas flow controller (MFC: Mass Flow Controller) method, or a method for transporting a liquid (LDS: Liquid Delivery System) using a liquid flow controller (LMFC: Liquid Mass Flow Controller) method, and preferably the LDS method is used.

[0194] In this case, the carrier gas or dilution gas for transferring the step coverage improving agent and 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 (N2), helium (He), neon (Ne), xenon (Xe), and krypton (Kr), but is not limited thereto.

[0195] In this description, the purge gas may be, for example, an inert gas, and preferably the above-mentioned carrier gas or diluent gas.

[0196]

[0197] Then, a reaction gas is supplied. The reaction gas is not particularly limited as long as it is a reaction gas commonly used in the technical field to which the present invention belongs, and may preferably include a nitriding agent, an oxidizing agent, or a reducing agent. The nitriding agent reacts with the precursor compound adsorbed on the substrate to form a nitride film, the oxidizing agent reacts with the precursor compound to form an oxide film, and the reducing agent reacts with the precursor compound to form a metal film.

[0198] Preferably, the nitriding agent can be nitrogen gas (N2), hydrazine gas (N2H4), or a mixture of nitrogen gas and hydrogen gas.

[0199] Preferably, the oxidizing agent may be ozone gas (O3), oxygen gas (O2), water vapor (H2O), hydrogen peroxide (H2O2), nitric oxide (NO2, N2O) and mixtures thereof.

[0200] Preferably, the reducing agent can be hydrogen gas (H2), acetic acid gas (HCOOH), ammonia gas (NH3), and mixtures thereof.

[0201] The remaining unreacted reactant gas is then purged with an inert gas, which removes not only the excess reactant gas but also any by-products that are produced.

[0202]

[0203] As described above, the thin film formation method, for example, includes a unit cycle including a step of activating a step coverage improving agent on a substrate, a step of shielding the substrate with the step coverage improving agent, a step of purging unadsorbed step coverage improving agent, a step of adsorbing a precursor compound / thin film forming composition onto the substrate, a step of purging unadsorbed precursor compound / thin film forming composition, a step of supplying a reactive gas, and a step of purging residual reactive gas, and the unit cycle can be repeated to form a thin film of a desired thickness.

[0204] As another example, the thin film formation method has a unit cycle including a step of adsorbing a precursor compound / thin film forming composition onto a substrate, a step of purging the unadsorbed precursor compound / thin film forming composition, a step of adsorbing a step coverage improving agent onto the substrate, a step of purging the unadsorbed step coverage improving agent, a step of supplying a reactive gas, and a step of purging the remaining reactive gas, and the unit cycle can be repeated to form a thin film of a desired thickness.

[0205] 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, the desired thin film characteristics can be effectively exhibited.

[0206]

[0207] The present invention also provides a semiconductor substrate, characterized in that the semiconductor substrate is manufactured by the thin film formation method described above. In such a case, the thin film has excellent step coverage and thickness uniformity, and has excellent density and electrical properties.

[0208]

[0209] The thin film may have a thickness of, for example, 0.1 to 20 nm, preferably 0.5 to 20 nm, more preferably 1.5 to 15 nm, and even more preferably 2 to 10 nm. Within this range, the thin film has the effect of having excellent thin film properties.

[0210] The thin film may have a carbon impurity content of preferably 5,000 counts / sec or less or 1 to 3,000 counts / sec, more preferably 10 to 1,000 counts / sec, and even more preferably 50 to 500 counts / sec. Within this range, there is an effect that the thin film growth rate is reduced while the thin film properties are excellent.

[0211] As an example, the thin film has a step coverage of 90% or more, preferably 92% or more, and more preferably 95% or more. Within this range, even if the thin film has a complex structure, it can be easily deposited on a substrate, and has the advantage that it can be applied to next-generation semiconductor devices.

[0212] The thin film thus produced preferably has a thickness of 20 nm or less, a dielectric constant of 5 to 29 based on a thickness of 10 nm, a carbon, nitrogen, and halogen content of 5,000 counts / sec or less, and a step coverage rate of 90% or more. Within these ranges, the thin film has excellent performance as a dielectric film or blocking film, but is not limited thereto.

[0213]

[0214] The thin film may have a multilayer structure of two or more layers, preferably two or three layers, as required. The multilayer film having a two-layer structure may have a lower layer film-middle layer film structure as a specific example, and the multilayer film having a three-layer structure may have a lower layer film-middle layer film-upper layer film structure as a specific example.

[0215] The underlayer film may, for example, comprise 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.

[0216] The intermediate layer is, for example, Ti x N y , preferably TN.

[0217] The upper layer film may contain, for example, one or more selected from the group consisting of W and Mo.

[0218]

[0219] Below, preferred embodiments and drawings are presented to aid in understanding the present invention. However, the following embodiments 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 spirit thereof. It goes without saying that such changes and modifications are also included within the scope of the appended claims.

[0220]

[0221] EXAMPLES

[0222] Example 1, Comparative Examples 1 to 5

[0223] The ALD deposition process was carried out using the components shown in Table 1 below and following the steps shown in FIG. 1 below.

[0224] FIG. 1 is a schematic diagram illustrating a deposition process sequence according to the present invention, focusing on one cycle.

[0225] Specifically, as the step coverage improving agent, a compound represented by the following chemical formula 1-6, a compound represented by the following chemical formula 1-7, a compound represented by the following chemical formula 1-8, a compound represented by the following chemical formula 1-9, and a compound represented by the following chemical formula 1-10 were prepared.

[0226] Chemical formula 1-6

[0227] [ka]

[0228] Chemical formula 1-7

[0229] [ka]

[0230] Chemical formula 1-8

[0231] [ka]

[0232] Chemical formula 1-9

[0233] [ka]

[0234] Chemical formula 1-10

[0235] [ka]

[0236] In addition, tris(dimethylamido)cyclopentadienylhafnium, CpHf(NMe2)3), was prepared as a precursor (shown as "CpHf" in Table 1 below).

[0237] Argon was flowed into the chamber at 5000 ml / min, and the pressure inside the chamber was adjusted to 1.5 Torr by a vacuum pump to form a thin inert atmosphere.

[0238] The step coverage improving agent shown in Table 1 below was placed in a canister, and the partial pressure and temperature were adjusted to the injection amount (mg / cycle). The canister was then loaded into a deposition chamber with a substrate loaded therein for 1 second to coat the substrate, and the chamber was purged for 10 seconds.

[0239] The precursor compounds were then loaded into the deposition chamber in canisters using a vapor flow controller (VFC) as shown in Table 1, and the chamber was purged for 10 seconds.

[0240] Next, the concentration of O3 in the reactive gas O2 is 200 g / m 3The mixture was placed in a deposition chamber as shown in Table 1, and the chamber was purged for 10 seconds. At this time, the substrate on which the thin film was to be formed was heated under the temperature conditions shown in Table 1 below.

[0241] This process was repeated 100 to 400 times to form a self-limiting atomic layer thin film with a thickness of 10 nm.

[0242] For each of the obtained thin films of Example 1 and Comparative Examples 1 to 5, the deposition rate reduction rate (D / R reduction rate), secondary ion mass spectrometry (SIMS) C impurities, and step coverage were measured by the following method, and the results are shown in Table 1 and FIG. 2.

[0243] * Deposition rate reduction rate (D / R (dep.rate) reduction rate): This refers to the ratio of the deposition rate reduction after the introduction of the shielding material compared to the D / R before the introduction of the step coverage improving agent, and was calculated as a percentage using the measured A / cycle values.

[0244] Specifically, the film thickness of the thin film was measured using an ellipsometer, which is a device capable of measuring optical properties such as the film thickness and refractive index of the thin film using the polarization properties of light, and divided by the number of cycles to calculate the film thickness deposited per cycle, and the reduction rate of the thin film growth rate was calculated. Specifically, it was calculated using the following Equation 1.

[0245] Formula 1

[0246]

number

[0247] (In the above formula, DR (Deposition rate, Å / cycle) is the rate at which a thin film is deposited. When a thin film is deposited by a precursor and a reactant, DR i (initial deposition rate) is the deposition rate of the thin film formed without adding a step coverage improving agent. DRf (final deposition rate) is the deposition rate of the thin film formed by adding a step coverage improving agent when carrying out the above-mentioned process. Here, the deposition rate (DR) is a value measured by an ellipsometer device under conditions of room temperature and normal pressure for a thin film having a thickness of 3 to 30 nm, and is expressed in Å / cycle units.)

[0248] *The non-uniformity was calculated by selecting the maximum and minimum film thicknesses from those measured by the ellipsometer and using the following formula 2, and the results are shown in Table 1. Specifically, the film thickness was measured at four points on the north, south, east and west edges of a 300 mm wafer and at one point in the center.

[0249] Equation 2

[0250]

number

[0251] * SIMS (Secondary-ion mass spectrometry) C impurity: The C impurity value in the SIMS graph was confirmed by considering the C impurity counts at the moment corresponding to the middle part of the thin film deposited by etching 5 nm or more, which is the least contaminated depth in the surface layer of the substrate, while digging the thin film in the axial direction by ion sputtering, and is shown in Table 1 and Figure 2 below.

[0252] *Step coverage (%): The thin films deposited on a substrate with a complex structure having an aspect ratio of 22:1 according to Examples 1-2 and Comparative Examples 1-3 were horizontally cut at a position 100 nm from the top to the bottom (left figure) and at a position 100 nm from the bottom to the top (right figure). The step coverage was measured using a transmission electron microscope (TEM) and calculated according to the following formula 3.

[0253] Equation 3

[0254]

number

[0255] Specifically, a deposition process was performed under conditions for applying a diffusion-improving material to a substrate with a complex structure with an aspect ratio of 22:1, with an upper diameter of 90 nm, a lower diameter of 65 nm, and a via hole depth of approximately 2000 nm. In order to confirm the uniformity of the thickness deposited inside the vertically formed via hole and the step coverage, samples were prepared by cutting horizontally at a position 100 nm from the top to the bottom and at a position 100 nm from the bottom to the top. The results were measured using a transmission electron microscope (TEM) and are shown in Table 1 below and Figures 3 and 4 below.

[0256] [Table 1-1] [Table 1-2]

[0257] In the table, CpHf is an abbreviation for tris(dimethylamido)cyclopentadienyl hafnium.

[0258] As shown in Table 1 and FIG. 2 below, it was confirmed that Example 1, in which the step coverage improving agent according to the present invention was used, had excellent step coverage compared to Comparative Example 1, in which the agent was not used.

[0259] In addition, it was confirmed that Example 1, which used the step coverage improving agent according to the present invention, not only improved the deposition rate reduction rate, but also had excellent impurity reduction properties and step coverage properties, compared to Comparative Examples 2 to 5, which used other types of agent that were not appropriate.

[0260] It is expected that this will enable effective step coverage to be achieved even on pattern substrates with high aspect ratios. In fact, it was confirmed that the step coverage measured in Example 1 of the present invention was excellent at 103.5%, while the step coverage measured in Comparative Examples 1 to 4 was 23.6% or more, with a maximum of 84.9% (see Figures 3 to 4 below).

Claims

1. A step coverage improving agent comprising a compound represented by the following chemical formula 1: Chemical formula 1 【Chemistry 1】 (In the above Chemical Formula 1, R １ and R ２ are each independently H or an alkyl group having 1 to 5 carbon atoms, and n is an integer of 2 to 4.

2. The step coverage improver according to claim 1, comprising at least one compound selected from the group consisting of compounds represented by the following formulas 1-1 to 1-6: Chemical formulas 1-1 to 1-6 【Chemistry 2】

3. 2. The step coverage improver according to claim 1, wherein the step coverage improver provides a shielding region for an oxide film, a nitride film, a metal film, or a selective thin film thereof, and the shielding region is formed on the entire substrate or a portion of the substrate on which the oxide film, the nitride film, the metal film, or a selective thin film thereof is formed.

4. 2. The step coverage improving agent according to claim 1, wherein the thin film improves step coverage during the formation of a laminate film of one or more elements selected from the group consisting of Al, Si, Ti, V, Co, Ni, Cu, Zn, Ga, Ge, Se, Zr, Nb, Mo, Ru, Rh, In, Sn, Sb, Te, Hf, Ta, W, Re, Os, Ir, La, Ce, and Nd.

5. 1. A method for forming a thin film, comprising the steps of: injecting a step coverage improving agent represented by the following formula 1 into a chamber to shield a surface of a loaded substrate: Chemical formula 1 【Chemistry 3】 (In the above Chemical Formula 1, R １ and R ２ are each independently H or an alkyl group having 1 to 5 carbon atoms, and n is an integer of 2 to 4.

6. 6. The method of claim 5, wherein the chamber is an atomic layer deposition (ALD) chamber, a chemical vapor deposition (CVD) chamber, a plasma enhanced atomic layer deposition (PEALD) chamber, or a plasma enhanced chemical vapor deposition (PECVD) chamber.

7. 6. The method of claim 5, wherein the step coverage improving agent is delivered into the chamber by a vapor flow control (VFC), direct liquid introduction (DLI), or liquid delivery system (LDS), and the thin film is a silicon nitride film, a silicon oxide film, a titanium nitride film, a titanium oxide film, a tungsten nitride film, a molybdenum nitride film, a hafnium oxide film, a zirconium oxide film, a tungsten oxide film, or an aluminum oxide film.

8. A semiconductor substrate comprising a thin film produced by the thin film formation method according to claim 5.

9. 9. The semiconductor substrate according to claim 8, wherein the thin film has a multi-layer structure of two or more layers.

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

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