A method for forming a thin film using two types of silicon precursor compounds.

Abstract

To provide a method for efficiently producing a thin film even at a low temperature using two types of silicon precursors, and to provide a thin film produced by this method that has excellent properties.SOLUTION: This application relates to a method for manufacturing a silicon thin film using two silicon precursor compounds, specifically, a method for manufacturing a silicon thin film that has excellent thin film properties even at low temperatures through atomic layer deposition (ALD) and allows for the morphology to be adjusted depending on the precursor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This application relates to a method for forming a silicon thin film with excellent properties even at low temperatures via atomic layer deposition (ALD) using two types of silicon precursors. [Background technology]

[0002] Recently, silicon-containing thin films can be manufactured in various forms through various processes in the semiconductor field. In particular, silicon oxide films and silicon nitride films can be used in equipment fabrication as insulating films, diffusion prevention films, hard masks, etching stop layers, seed layers, spacers, trench isolation, intermetallic dielectric materials, or protective film layers due to their extremely excellent barrier properties and oxidation resistance. Recently, polycrystalline silicon thin films have been used in thin-film transistors (TFTs) and solar cells, and their application fields are gradually diversifying.

[0003] For the production of silicon-containing thin films, well-known representative technologies include atomic layer deposition (ALD), in which a gaseous precursor is physically or chemically adsorbed onto the substrate surface, followed by the sequential introduction of reaction gases to form a film; and metal-organic chemical vapor deposition (MOCVD), in which a mixed gaseous organometallic precursor reacts with a reaction gas to form a film on the substrate surface, or reacts directly on the surface to form a film. Various thin-film manufacturing technologies, such as low-pressure chemical vapor deposition (LPCVD) and low-temperature plasma-based chemical vapor deposition (PECVD) and atomic layer deposition (PEALD), which apply these technologies, are applied to the manufacturing processes of next-generation semiconductors and other devices, and are used for ultra-fine pattern formation and thin-film deposition with uniform and excellent properties at nanoscale thicknesses.

[0004] In particular, thin films used in semiconductor devices must be controllable at the atomic level and possess excellent step coverage properties. Atomic layer deposition (ALD) is a technology applicable to this. The development of highly isotropic thin film deposition methods capable of nanoscale thickness adjustment is a crucial factor, making ALD the most promising deposition technology for many applications in nanoscale devices. Atomic layer deposition is expected to solve problems caused by device miniaturization, such as high leakage current, and, in addition to the deposition of a single high-dielectric material, it also has the additional advantage of being able to deposit thin films with atomic-level compositional variations. The principle of atomic layer deposition is that one atomic layer is deposited by supplying each reactant, separated by an inert gas (Ar, N2, etc.), onto a wafer, and this process is repeated to deposit the desired thickness. One reactant undergoes chemiadsorption on the substrate to which the thin film is deposited, after which a second or third gas is introduced, and chemiadsorption occurs again on the substrate, forming the thin film. The reactants must be single elements or compounds, and such reactants must be highly volatile, stable, and highly reactive.

[0005] However, using precursors that are used in existing atomic layer deposition methods requires a high-temperature process of 600°C or higher. At the same time, the reactants decompose in the high-temperature process, causing defects and resulting in a decrease in the physical and electrical properties of the thin film, such as step coverage and etching characteristics.

[0006] This has increased the need for processes that offer low-temperature behavior in the vapor deposition process, excellent adhesion of thin films, superior step coating capabilities, and the ability to adjust thickness at the atomic layer level.

[0007] Consequently, there is a need to develop a method for manufacturing thin films that allows for atomic layer deposition even at low temperatures, possesses excellent step-level coating properties, and exhibits superior thin-film characteristics. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Korean Registered Patent Publication No. 10-1436564 [Overview of the project] [Problems that the invention aims to solve]

[0009] This invention aims to provide a method for efficiently manufacturing thin films even at low temperatures using two types of silicon precursors, and to provide thin films with excellent properties manufactured through this method.

[0010] In particular, existing silicon thin film deposition methods are low-pressure chemical vapor deposition (LPCVD), which results in the formation of silicon thin films containing defects. Consequently, during high-temperature crystallization, polycrystalline silicon (poly-Si) thin films with small grain boundary sizes are formed.

[0011] This invention aims to provide a thin film manufacturing method that applies two types of silicon precursors to an atomic layer deposition method that utilizes thermal energy instead of existing plasma, thereby ensuring ALD behavior even at low temperatures below 500°C and enabling conformal deposition of patterns with a high aspect ratio.

[0012] However, the problems that this application seeks to solve are not limited to those mentioned above, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

[0013] However, the problems that this invention aims to solve are not limited to those mentioned above, and other problems that are not mentioned will be clearly understood by those with ordinary skill in the art to which this invention belongs from the content that will be described later. [Means for solving the problem]

[0014] A first injection step of injecting a first precursor compound into a chamber,

[0015] and a second injection step of injecting a second precursor compound into the chamber, wherein a first cycle including the first injection step and the second injection step is repeated to deposit a thin film,

[0016] the first precursor compound is represented by the following Chemical Formula 1,

[0017] and the second precursor compound is represented by the following Chemical Formula 2,

[0018] method for manufacturing a thin film.

[0019] [Chemical Formula 1] Si(R1) x H (4-x)

[0020] [Chemical Formula 2] Si y (R2) z H (2y+2-z)

[0021] In Chemical Formulas 1 and 2 described above,

[0022] R1 and R2 are each independently any one selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I),

[0023] x is an integer of 1 to 4,

[0024] when y is 1, z is an integer of 0 to 4,

[0025] and when y is 2 or 3, z is an integer of 0 to 6. [Advantageous Effects of Invention]

[0026] The method for manufacturing a thin film of the present application has the effect of being capable of efficiently manufacturing a silicon thin film with excellent properties.

[0027] Specifically, this invention enables atomic layer deposition even at low temperatures of 500°C or below by introducing two types of silicon precursor compounds, and by using the precursor compounds as a source and reactant, it is possible to deposit thin films that are either amorphous or nanocrystalline depending on the type of precursor compound.

[0028] In particular, by depositing an amorphous silicon thin film and then crystallizing it, it is possible to produce a polycrystalline silicon thin film with a large grain boundary size.

[0029] In other words, the thin film manufacturing method of the present invention uses two types of silicon precursor compounds to enable uniform thin film deposition with excellent properties even at low temperatures, thereby ensuring excellent thin film properties, thickness, and step coverage, and allowing for adjustment of the morphology and crystallinity of the deposited thin film.

[0030] Furthermore, thin films with excellent properties produced by the thin film manufacturing method of the present invention can be used as dielectrics for various electronic devices, displays, next-generation memories, non-memory semiconductors, and the like. [Brief explanation of the drawing]

[0031] [Figure 1] This is a schematic diagram of the process for manufacturing a silicon seed layer and oxidizing or nitriding the silicon seed layer. [Figure 2] This is a schematic diagram of the process for manufacturing a silicon thin film and oxidizing or nitriding the silicon thin film. [Modes for carrying out the invention]

[0032] The operation and effects of the invention will be described in more detail below through specific embodiments and drawings of the invention. However, these embodiments are presented only as examples of the invention and do not determine the scope of the invention's rights.

[0033] Prior to this, terms and words used in this specification and claims should not be interpreted in a manner limited to their ordinary or dictionary meanings, but rather in a manner consistent with the technical idea of ​​the present invention, based on the principle that inventors may define the concepts of terms as appropriate to describe their invention in the best possible way.

[0034] Therefore, the configurations of the embodiments described herein represent only one of the most preferred embodiments of the present invention and do not represent the entire technical concept of the present invention. It should be understood that various equivalents and modifications may exist that can substitute for these at the time of filing.

[0035] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as “includes,” “equip,” or “have” are intended to specify the existence of implemented features, figures, steps, components, or combinations thereof, and should be understood not to preemptively exclude the existence or possibility of adding one or more other features, figures, steps, components, or combinations thereof.

[0036] Wherever various parameters are given herein as ranges, preferred ranges, or lists of preferred upper and lower limits, it should be understood that this specifically discloses all ranges formed by any pair of any upper range limits or preferred values ​​and any lower range limits or preferred values, regardless of whether the ranges are disclosed separately.

[0037] Where a range of numbers is referred to herein, unless otherwise specified, that range is intended to include its endpoint and all integers and fractions within that range.

[0038] The scope of the present invention is intended not to be limited to specific values ​​mentioned when defining a range.

[0039] In the present specification, for "a to b" and "a~b" representing a numerical range, "to" and "~" are defined as ≥a and ≤b.

[0040] A method of manufacturing a thin film according to one aspect of the present application may be a thin film manufacturing method in which a first cycle including a first injection step of injecting a first precursor compound into a chamber and a second injection step of injecting a second precursor compound into the chamber is repeated to deposit a thin film, wherein the first precursor compound is represented by the following Chemical Formula 1, and the second precursor compound is represented by the following Chemical Formula 2.

[0041] [Chem. 1] Si(R1) x H (4-x)

[0042] [Chem. 2] Si y (R2) z H (2y+2-z)

[0043] In the above Chemical Formulas 1 and 2,

[0044] R1 and R2 are each independently any one selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I),

[0045] x is an integer of 1 to 4,

[0046] when y is 1, z is an integer of 0 to 4,

[0047] when y is 2 or 3, z may be an integer of 0 to 6.

[0048] At this time, when the number following an atom is 0, it may mean that the atom is not included.

[0049] Further, the above Chemical Formula 2 may be the same as or different from the above Chemical Formula 1.

[0050] In this application, the term "chamber" can mean the internal space of a reaction group where a thin-film deposition process is carried out.

[0051] The first cycle may consist of one or more cycles, and no more than 1,000 cycles. For example, it may consist of 50 or more cycles, 100 or more cycles, 200 or more cycles, 300 or more cycles, 400 or more cycles, or 500 or more cycles.

[0052] In one embodiment of the present invention, R1 in chemical formula 1 may be iodine (I), and x may be 2.

[0053] For example, the first precursor compound may be SiI2H2.

[0054] In one embodiment of the present invention, R2 in chemical formula 2 is chlorine (Cl), y is 2, and z may be 4 or 5.

[0055] For example, the second precursor compound may be Si2Cl4H2 or Si2Cl5H.

[0056] On the other hand, if the second precursor compound is not included, the ALD behavior may not be smooth at low temperatures below 500°C, and the morphological properties of the deposited thin film may deteriorate.

[0057] The method for manufacturing the thin film may be atomic layer deposition (ALD), chemical vapor deposition (CVD), or a combination thereof, and preferably atomic layer deposition (ALD), but is not limited thereto.

[0058] Atomic layer deposition (ADD) is a deposition method that involves repeatedly adsorbing a precursor onto a substrate, purging the residual precursor with a purge gas, reacting it with a reaction gas, and then purging the residual reaction gas with a purge gas. By using ADD, films can be formed with thinner thicknesses and achieve high uniformity. Furthermore, by repeating each step of ADD, thin films of a desired thickness can be formed on the substrate.

[0059] In atomic layer deposition, reactants must be highly volatile, stable, and highly reactive. Atomic layer deposition is a method in which reactants are supplied separately, and during one deposition cycle, a thin film below the monolayer is grown by surface reactions. Ligands of the reactants adsorbed on the substrate can be removed through chemical reactions with other reactants supplied later. When heating the precursor compounds, which are reactants, for atomic layer deposition, the liquid phase offers significant advantages in terms of reaction rate and process compared to the solid phase.

[0060] The first precursor compound of the present application is a compound containing silicon (Si) atoms and may be a colorless liquid phase at room temperature.

[0061] In one embodiment of the present invention, a first purge step of injecting a first purge gas into the chamber may be further included between the first injection step and the second injection step, and a second purge step of injecting a second purge gas into the chamber after the second injection step.

[0062] In this case, the first and second purge gases can independently utilize hydrogen (H2), argon (Ar), nitrogen (N2), helium (He), noble gases, inert gases, or combinations thereof.

[0063] In one embodiment of the present invention, hydrogen gas (H2) can be injected simultaneously in the first injection step and / or the second injection step to adjust the hydrogen (H) content of the thin film and to adjust the impurity concentration of halogen atoms.

[0064] Furthermore, by simultaneously injecting hydrogen gas (H2) into the first and / or second purge step, the hydrogen (H) content of the thin film can be adjusted, thereby adjusting the impurity concentration of halogen atoms.

[0065] In one embodiment of the present application, the compound represented by chemical formula 1 may be one or more selected from the group consisting of fluorosilane, chlorosilane, bromosilane, iodosilane, difluorosilane, dichlorosilane, dibromosilane, diiodosilane (DIS, SiI2H2), trifluorosilane, trichlorosilane, tribromosilane, triiodosilane, tetrafluorosilane, tetrachlorosilane, tetrabromosilane, and tetraiodosilane.

[0066] For example, the precursor compound that can be represented by the chemical formula 1 may be, but is not limited to, a diiodosilane (DIS).

[0067] In one example of the realization of this application, the compound represented by chemical formula 2 is silane (SiH4), fluorosilane, chlorosilane, bromosilane, iodosilane, difluorosilane, dichlorosilane, dibromosilane, diiodosilane (DIS, SiI2H2), trifluorosilane, trichlorosilane, tribromosilane, triiodosilane, tetrafluorosilane, tetrachlorosilane, tetrabromosilane, tetraiodosilane. silane), disilane (Si2H6), fluorodisilane, chlorodisilane, bromodisilane, iododisilane, difluorodisilane, dichlorodisilane, dibromodisilane, diiododisilane, trifluorodisilane, trichlorodisilane, tribromodisilane, triiododisilane, tetrafluorodisilane, tetrachlorodisilane (TCDS, Si2Cl4H2), tetrabromodisilane (Tetrabromo disilane, tetraiododisilane, pentafluorodisilanedisilane), pentachlorodisilane (PCDS, Si2Cl5H), pentabromo disilane, pentaiododisilane, hexafluorodisilane, hexachlorodisilane, hexabromo disilane, hexaiododisilane, trisilane (Si3H8), fluorotrisilane, chlorotrisilane, bromotrisilane, iodotrisilane, difluorotrisilane, dichlorotrisilane, dibromo Trisilane, Diiodotrisilane, Trifluorotrisilane, Trichlorotrisilane, Tribromotrisilane, Triiodotrisilane, Tetrafluorotrisilane, Tetrachlorotrisilane, Tetrabromotrisilane, Tetraiodotrisilane, Pentafluorotrisilane, Pentachlorotrisilane, Pentabromotrisilane, Pentaiodotrisilane, Hexafluorotrisilane, Hexachlorotrisilane Hexabromo trisilaneIt may be one or more selected from the group consisting of trisilane and hexaiodotrisilane.

[0068] For example, the compound that can be represented by the chemical formula 2 may be any one selected from the group consisting of tetrachlorodisilane (TCDS) and pentachlorodisilane (PCDS), but is not limited thereto.

[0069] In one embodiment of the present invention, the process temperature in which the thin film manufacturing method is carried out may be 350°C or higher and 500°C or lower.

[0070] For example, the process temperature can be 350°C or higher and 500°C or lower, 360°C or higher and 500°C or lower, 370°C or higher and 500°C or lower, 380°C or higher and 500°C or lower, 390°C or higher and 500°C or lower, 400°C or higher and 500°C or lower, 370°C or higher and 490°C or lower, 390°C or higher and 485°C or lower, 395°C or higher and 480°C or lower, 400°C or higher and 475°C or lower, 360°C or higher and 480°C or lower, 370°C or higher and 460°C or lower, 380°C or higher and 440°C or lower, 390°C or higher and 430°C or lower, 400°C or higher and 420°C or lower, 350°C or higher and 490°C or lower, or 350°C or higher and 480°C The following ranges may also be used: 350°C to 470°C, 350°C to 460°C, 350°C to 450°C, 350°C to 440°C, 350°C to 430°C, 350°C to 420°C, 350°C to 410°C, 350°C to 400°C, 360°C to 450°C, 370°C to 450°C, 380°C to 450°C, 390°C to 450°C, 400°C to 450°C, 410°C to 450°C, 420°C to 450°C, 430°C to 450°C, and 440°C to 450°C.

[0071] Specifically, when the first precursor compound is diiodosilane (DIS), the process temperature may be 350°C or higher and 500°C or lower, preferably 400°C or higher and 500°C or lower, and more preferably 400°C or higher and 450°C or lower.

[0072] On the other hand, when manufacturing thin films according to this invention at low temperatures below 350°C, deposition may not occur correctly. This is because the reaction rate is insufficient, and the deposition rate may become even slower. In addition, the second precursor compound may not diffuse sufficiently, which can lead to defects and uniformity issues in the material and thin film, potentially causing instability in the substrate and thin film.

[0073] Furthermore, when manufacturing thin films according to this invention at temperatures exceeding 500°C, deposition may not occur correctly. This is because the reaction rate becomes too fast, potentially leading to the generation of impurities, and the precursor or reaction gas may decompose, making thin film formation difficult.

[0074] In one example, when the first precursor compound is diiodosilane and the second precursor compound is tetrachlorodisilane, the thin film deposition rate (GPC) by the above manufacturing method may be 0.1 to 0.3 Å / cycle at a process temperature in the range of 400 to 450°C. In other words, the thin film deposition rate by the manufacturing method in the process temperature range of 400 to 450°C may be 0.1 to 0.3 Å / cycle, 0.12 to 0.28 Å / cycle, 0.14 to 0.26 Å / cycle, 0.16 to 0.24 Å / cycle, 0.18 to 0.24 Å / cycle, 0.19 to 0.24 Å / cycle, 0.20 to 0.24 Å / cycle, 0.215 to 0.24 Å / cycle, 0.18 to 0.22 Å / cycle, 0.19 to 0.22 Å / cycle, 0.20 to 0.22 Å / cycle, or 0.215 to 0.22 Å / cycle.

[0075] In one example, when the first precursor compound is diiodosilane and the second precursor compound is pentachlorodisilane, the thin film deposition rate by the manufacturing method in the process temperature range of 420-450°C may be 0.1-0.3 Å / cycle. That is, the thin film deposition rate by the manufacturing method in the process temperature range of 420-450°C may be 0.1-0.3 Å / cycle, 0.12-0.28 Å / cycle, 0.14-0.26 Å / cycle, 0.16-0.24 Å / cycle, 0.18-0.24 Å / cycle, 0.19-0.24 Å / cycle, 0.20-0.24 Å / cycle, 0.215-0.24 Å / cycle, 0.18-0.22 Å / cycle, 0.19-0.22 Å / cycle, 0.20-0.22 Å / cycle, or 0.215-0.22 Å / cycle.

[0076] In one implementation example, the temperature of the canister containing the first precursor compound may be 0°C or higher and 50°C or lower.

[0077] For example, the temperature of the canister of the first precursor compound may be 0°C to 50°C, 5°C to 45°C, 10°C to 40°C, 15°C to 35°C, 20°C to 25°C, 20°C to 30°C, 25°C to 30°C, 5°C to 30°C, 10°C to 30°C, or 15°C to 30°C.

[0078] Furthermore, the canister temperature of the second precursor compound may be between 0°C and 30°C.

[0079] For example, the temperature of the canister of the second precursor compound may be 0°C to 30°C, 0°C to 25°C, 0°C to 20°C, 5°C to 25°C, 5°C to 20°C, 5°C to 15°C, 10°C to 30°C, 10°C to 25°C, 10°C to 20°C, 10°C to 15°C, 15°C to 30°C, 15°C to 25°C, or 15°C to 20°C.

[0080] A canister is used in a thin film manufacturing method to supply a source gas and a reaction gas into a reaction chamber. Typically, the canister vaporizes a precursor compound to generate the source gas and reaction gas, and then supplies these gases into the chamber.

[0081] If the temperature of the canister falls outside the range, the uniformity of the thickness of the thin film produced by the thin film manufacturing method may decrease significantly.

[0082] This is because, below the minimum temperature range, the supply of the precursor compound to the chamber is insufficient, and above the maximum temperature range, it can be difficult to obtain a uniform film quality due to alteration caused by thermal energy or an excessive supply of the precursor compound to the chamber.

[0083] In one implementation example, the injection time of the first precursor compound may be 1 second or more and 30 seconds or less, and the injection time of the second precursor compound may be 1 second or more and 30 seconds or less, preferably the injection time of the first precursor compound may be 1 second or more and 15 seconds or less, and the injection time of the second precursor compound may be 1 second or more and 15 seconds or less.

[0084] For example, the injection time of the aforementioned first precursor compound is 1 second to 20 seconds, 1 second to 15 seconds, 2 seconds to 15 seconds, 3 seconds to 15 seconds, 4 seconds to 15 seconds, 5 seconds to 15 seconds, 2 seconds to 10 seconds, 3 seconds to 10 seconds, 4 seconds to 10 seconds, 5 seconds to 10 seconds, 1 second to 10 seconds, 1 second to 8 seconds, 1 second to 6 seconds, and 1 second to 5 seconds.

[0085] The injection time of the second precursor compound may be 1 second to 20 seconds, 1 second to 15 seconds, 2 seconds to 15 seconds, 3 seconds to 15 seconds, 4 seconds to 15 seconds, 5 seconds to 15 seconds, 2 seconds to 10 seconds, 3 seconds to 10 seconds, 4 seconds to 10 seconds, 5 seconds to 10 seconds, 1 second to 10 seconds, 1 second to 8 seconds, 1 second to 6 seconds, or 1 second to 5 seconds.

[0086] If the injection time for the first and second precursor compounds described above is exceeded or not met, and the process proceeds, it may be difficult to form a suitable thin film.

[0087] Specifically, if the injection time of the first precursor compound is less than the range, there may not be enough reactants necessary for thin film formation, and a thin film of appropriate thickness may not be formed. On the other hand, if the injection time of the first precursor compound exceeds the range, the composition ratio of the thin film produced after the reaction may become inconsistent due to impurities from residual compounds.

[0088] Furthermore, the injection time of the second precursor compound can be varied depending on the type of the first precursor compound.

[0089] For example, if the first precursor compound is diiodosilane (DIS), the injection time of the second precursor compound may be 1 second to 20 seconds, 2 seconds to 19 seconds, 3 seconds to 18 seconds, 4 seconds to 17 seconds, preferably 5 seconds to 15 seconds.

[0090] If the injection time of the second precursor compound is less than 1 second, the residual amount of the first precursor compound, which is a reactant, may increase, leading to an improper reaction and the formation of impurities, resulting in the uneven deposition of the thin film layer. On the other hand, if the injection time of the second precursor compound exceeds 30 seconds, impurities due to the second precursor compound may be generated.

[0091] In one implementation example, the purge gas injection time in the first purge step may be 1 second or more and 1 minute or less, and the purge gas injection time in the second purge step may be 1 second or more and 1 minute or less.

[0092] In one implementation example, the first purge gas injection time of the first purge step is 1 second to 60 seconds, 1 second to 50 seconds, 1 second to 40 seconds, 1 second to 30 seconds, 1 second to 20 seconds, 1 second to 15 seconds, or 1 second to 10 seconds.

[0093] The purge gas injection time in the second purge step may be 1 second to 60 seconds, 1 second to 50 seconds, 1 second to 40 seconds, 1 second to 30 seconds, 1 second to 20 seconds, 1 second to 15 seconds, or 1 second to 10 seconds.

[0094] If the injection time of the first or second purge gas is less than the range mentioned above, the residual amount of the first or second precursor compound may increase, leading to an improper reaction, impurities may not be purged, and the thin film layer may be deposited unevenly.

[0095] In one implementation example, the thin film produced when the first cycle is repeated one to 70 times may be a silicon seed layer. In this case, the silicon seed layer can form nucleation islands, and these nucleation islands can be formed randomly.

[0096] Furthermore, if a film is deposited after the nucleation island has been formed, the film may grow around the nucleation island.

[0097] The first cycle may be repeated, for example, 65 times or less, 60 times or less, 55 times or less, 50 times or less, 45 times or less, 40 times or less, 35 times or less, 30 times or less, 25 times or less, 20 times or less, 15 times or less, or 10 times or less.

[0098] Figure 1 shows the sequence of the first injection step, the first purge step, the second injection step, and the second purge step of the first cycle.

[0099] In one embodiment, after forming the silicon seed layer, a third injection step may be further included in which a compound containing hydrogen (H), nitrogen (N), oxygen (O), or a combination thereof is injected into the chamber.

[0100] Figure 1 shows the sequence of the third injection step and the third purging step. The third injection step and the third purging step may be performed selectively if nitriding or oxidation of the silicon seed layer is required. If the third injection step and the third purging step are not performed, the third injection step (160) and the third purging step (170) in Figure 1 may be omitted and the process may be terminated (180).

[0101] The compound of the third injection step can specifically mean hydrogen (H2), nitrogen (N2), ammonia (NH3), oxygen (O2), ozone (O3), or a combination thereof, and if the third injection step further includes, the silicon seed layer may be nitrided or oxidized.

[0102] For example, the silicon seed layer may be a silicon nitride film or a doped silicon nitride film, and the oxide film may be a silicon oxide film or a doped silicon oxide film.

[0103] In one implementation example, a third purge gas may be injected into the chamber after the third injection step. In this case, the third purge gas may be hydrogen (H2), argon (Ar), nitrogen (N2), helium (He), a noble gas, an inert gas, or a combination thereof.

[0104] In one implementation example, the third purge gas injection time of the third purge step may be 1 second or more and 60 seconds or less, 1 second or more and 50 seconds or less, 1 second or more and 40 seconds or less, 1 second or more and 30 seconds or less, 1 second or more and 20 seconds or less, 1 second or more and 15 seconds or less, or 1 second or more and 10 seconds or less.

[0105] If the injection time of the third purge gas is less than the range mentioned above, the amount of compound injected in the third injection step may increase, leading to an improper reaction, impurities may not be purged, and the thin film layer may be deposited unevenly.

[0106] In one embodiment, after forming the silicon seed layer, a second cycle may be further repeated, which includes a first injection step of injecting the first precursor compound onto the silicon seed layer and a second injection step of injecting the second precursor compound, to form a silicon thin film.

[0107] In other words, the silicon thin film can be produced by further repeating the second cycle after the first cycle, which is repeated one to seventy times.

[0108] The number of repetitions of the second cycle described above may be one or more and 500 or less. For example, it may be 400 or less, 300 or less, 200 or less, or 100 or less.

[0109] In this case, the silicon seed layer may be a silicon seed layer that has not undergone the third injection step, or a silicon seed layer that has been nitrided or oxidized further including the third injection step. Alternatively, the silicon seed layer may refer to a seed layer formed by injecting the third purge gas after the third injection step.

[0110] Figure 2 shows the sequence of the first injection step, the first purge step, the second injection step, and the second purge step of the second cycle.

[0111] In one implementation example, the silicon thin film formed on the silicon seed layer may be in any one of the following states: amorphous, a mixture of amorphous and nanocrystalline states, or nanocrystalline.

[0112] Generally, in atomic layer deposition methods, atoms and molecules are arranged in a disordered manner without a regular pattern. This typically occurs during rapid cooling processes or specific chemical steps, when there is not enough time to form a crystalline structure.

[0113] Amorphous thin films can be produced by atomic layer deposition processes, and materials in this state generally have consistent thermal, mechanical, and electrical properties in all directions.

[0114] The nanocrystalline state refers to a material that possesses a crystalline structure on the nanometer scale. Nanocrystals have unique physical properties due to their fine size and high surface-to-volume ratio. Materials in this state can exhibit different properties from amorphous materials in terms of electrical, optical, and mechanical properties. Thin films in the nanocrystalline state can be manufactured through atomic layer deposition processes.

[0115] In the thin film deposition process, the morphology of the thin film can be crystallized during the deposition process under specific conditions such as temperature, pressure, and deposition time, or crystallized after the deposition of the thin film by a crystallization treatment.

[0116] This invention allows for the adjustment of the surface morphology of the thin film depending on the type of first and second precursor compounds.

[0117] Furthermore, with the manufacturing method of the present invention, a thin film can be obtained in a state in which both a nanocrystalline state and an amorphous state and a nanocrystalline state are mixed, without undergoing any additional heat treatment after deposition.

[0118] In one implementation example, the silicon thin film may be a pure amorphous silicon (Si) thin film that does not contain carbon (C) and / or nitrogen (N). However, due to oxidation or contamination of the thin film surface, carbon (C), nitrogen (N), and / or oxygen (O) may be detected in the thin film.

[0119] In one implementation example, the grain size of the thin film produced by the above manufacturing method, as measured by SEM, may be 30 nm or more and 50 nm or less.

[0120] For example, the grain size may be between 30 nm and 50 nm, between 30.5 nm and 49 nm, between 31 nm and 48 nm, between 31 nm and 46 nm, between 31.7 nm and 45.2 nm, or between 37.3 nm and 47.6 nm.

[0121] In one implementation example, a crystallized silicon thin film can be formed by further heat treatment of an amorphous silicon thin film formed by the manufacturing method of the present invention.

[0122] At this time, the hydrogen (H) content of the thin film can be adjusted by simultaneously injecting hydrogen (H2) in the first injection step, the second injection step, the third injection step, the first purging step, the second purging step, the third purging step, the fourth injection step, the fourth purging step, or a combination thereof, and the grain size of the crystallized silicon thin film can be adjusted by adjusting the hydrogen (H) content in the thin film.

[0123] In one implementation example, the roughness of the thin film produced by the above manufacturing method, measured by AFM, may have an Rq value of 0.1 nm or more and 0.5 nm or less at a scan size of 5 μm.

[0124] For example, the Rq value may be between 0.1 nm and 0.5 nm, between 0.15 nm and 0.4 nm, between 0.15 nm and 0.3 nm, between 0.2 nm and 0.25 nm, between 0.2 nm and 0.3 nm, between 0.2 nm and 0.35 nm, between 0.2 nm and 0.4 nm, between 0.21 nm and 0.39 nm, between 0.22 nm and 0.36 nm, between 0.3 nm and 0.5 nm, between 0.31 nm and 0.49 nm, between 0.32 nm and 0.48 nm, between 0.33 nm and 0.46 nm, or between 0.34 nm and 0.45 nm.

[0125] In one implementation example, the roughness of the thin film produced by the above manufacturing method, measured by AFM, may have an Ra value of 0.1 nm or more and 0.4 nm or less at a scan size of 5 μm.

[0126] For example, the Ra value may be between 0.1 nm and 0.4 nm, 0.12 nm and 0.35 nm, 0.14 nm and 0.3 nm, 0.15 nm and 0.29 nm, 0.17 nm and 0.28 nm, 0.17 nm and 0.3 nm, 0.17 nm and 0.35 nm, 0.17 nm and 0.4 nm, 0.2 nm and 0.4 nm, 0.21 nm and 0.39 nm, 0.22 nm and 0.38 nm, 0.23 nm and 0.36 nm, or 0.24 nm and 0.35 nm.

[0127] In one embodiment, after the silicon has been formed, a fourth injection step may be included in which a compound comprising hydrogen (H), nitrogen (N), oxygen (O), or a combination thereof is injected into the chamber. The compound in the fourth injection step may specifically mean hydrogen (H2), nitrogen (N2), ammonia (NH3), oxygen (O2), ozone (O3), or a combination thereof, and if the third injection step is further included, the silicon seed layer may be nitrided or oxidized.

[0128] For example, the silicon seed layer may be a silicon nitride film or a doped silicon nitride film, and the oxide film may be a silicon oxide film or a doped silicon oxide film.

[0129] In one implementation example, a fourth purge gas can be injected into the chamber after the fourth injection step. In this case, the fourth purge gas can be hydrogen (H2), argon (Ar), nitrogen (N2), helium (He), a noble gas, an inert gas, or a combination thereof.

[0130] Figure 2 shows the sequence of the fourth injection step and the fourth purge step. The fourth injection step and the fourth purge step can be performed selectively if nitriding or oxidation of the silicon thin film is required. If the fourth injection step and the fourth purge step are not performed, the fourth injection step (260) and the fourth purge step (270) in Figure 2 may be omitted and the process may be terminated (280).

[0131] In one implementation example, the fourth purge gas injection time of the fourth purge step may be 1 second or more and 60 seconds or less, 1 second or more and 50 seconds or less, 1 second or more and 40 seconds or less, 1 second or more and 30 seconds or less, 1 second or more and 20 seconds or less, 1 second or more and 15 seconds or less, or 1 second or more and 10 seconds or less.

[0132] If the injection time of the fourth purge gas is less than the range described above, the amount of compound injected in the fourth injection step may increase, leading to an improper reaction, impurities may not be purged, and the thin film layer may be deposited unevenly.

[0133] The present application will be explained in more detail below using manufacturing examples, but the present application is not limited thereto.

[0134] [Manufacturing example]

[0135] Thin films were fabricated using atomic layer deposition (ALD) equipment, employing the first and second precursor compounds.

[0136] The substrate used in this experiment was a p-type SiO2 (110 nm) wafer with a resistance of 0.02 Ωcm. Prior to deposition, the p-type Si wafer was cleaned by sonication in acetone, ethanol, and deionized water (DI water) for 10 minutes each. The native oxide thin film on the Si wafer was removed by immersing it in a 1% HF (HF:H2O=1:100) solution for 10 seconds. The HF-cleaned Si wafer was immediately transferred to an atomic layer deposition (ALD) chamber.

[0137] Furthermore, as shown in Table 1 below, the first precursor compound used in the production of the thin film was diiodosilane (DIS).

[0138] The second precursor compounds used were tetrachlorodisilane (TCDS) and pentachlorodisilane (PCDS), respectively.

[0139] The temperature of the canister containing the first precursor compound was maintained at 25°C in Production Example 1 and at 5°C in Production Example 2.

[0140] The first precursor compound was supplied with argon (Ar) and the second precursor compound with argon (Ar) in that order, and this constituted one cycle.

[0141] In manufacturing example 1, the cycle was repeated 70 times, and in manufacturing example 2, the cycle was repeated 180 times.

[0142] The injection time for the first precursor compound (DIS) was adjusted to 3-10 seconds. At this time, the injection volume of the first precursor compound (DIS) was 100 sccm, and the process pressure was 3.2-4.0 Torr.

[0143] In production examples 1 and 2, the injection time of the second precursor compound was adjusted to 5 to 15 seconds. At this time, the injection volume of the second precursor compound was 100 sccm, and the process pressure was 3.0 to 4.0 torr.

[0144] In manufacturing example 3, the cycle was repeated 70 times, and in manufacturing example 4, the cycle was repeated 200 times.

[0145] The injection time for the first precursor compound (DIS) was adjusted to 3-10 seconds. At this time, the injection volume of the first precursor compound (DIS) was 100 sccm, and the process pressure was 3.2-4.0 Torr.

[0146] In production examples 3 and 4, the injection time of the second precursor compound was adjusted to 5 to 15 seconds. At this time, the injection volume of the second precursor compound was 100 sccm, and the process pressure was 3.0 to 4.0 torr.

[0147] In other words, in manufacturing examples 1 and 3, the silicon seed layer was manufactured by repeating the first injection step, the first purge step, the second injection step, and the second purge step in order 70 times, without proceeding with the third injection step and the third purge step as shown in Figure 1.

[0148] Furthermore, in manufacturing examples 2 and 4, unlike manufacturing examples 1 and 3 respectively, the third injection step and third purging step in Figure 1 were not performed, but the first injection step, first purging step, second injection step, and second purging step were repeated in order 70 times to produce a silicon seed layer, and then the first injection step, first purging step, second injection step, and second purging step in Figure 2 were repeated in order 110 and 130 times, respectively, to produce a silicon thin film on the silicon seed layer.

[0149] Table 1 below shows the process conditions for thin film manufacturing for each manufacturing example.

[0150] [Table 1]

[0151] In Table 1 above, DIS is diiodosilane, TCDS is tetrachlorodisilane, and PCDS is pentachlorodisilane.

[0152] In manufacturing example 5, ammonia (NH3) and argon (Ar) were sequentially supplied to the silicon thin film manufactured in manufacturing example 2.

[0153] In manufacturing example 6, ozone (O3) and argon (Ar) were sequentially supplied to the silicon thin film manufactured in manufacturing example 2.

[0154] In manufacturing example 7, ammonia (NH3) and argon (Ar) were sequentially supplied to the silicon thin film manufactured in manufacturing example 4.

[0155] In manufacturing example 8, ozone (O3) and argon (Ar) were sequentially supplied to the silicon thin film manufactured in manufacturing example 4.

[0156] In other words, in manufacturing examples 5 to 8, the silicon thin films produced in manufacturing examples 2 and 4 were further oxidized or nitrided by repeating the fourth injection step and fourth purging step in Figure 2.

[0157] Table 2 below shows the process conditions for manufacturing silicon thin films according to manufacturing examples 5 to 8.

[0158] [Table 2]

[0159] [Evaluation Example 1 - Change in thin film deposition rate due to the injection time of the first precursor compound]

[0160] Each thin film was manufactured according to the manufacturing example, with the injection time of the first precursor compound varied in the range of 3 to 10 seconds under the process conditions described in Table 1, and the deposition rate (GPC) of the thin film was measured.

[0161] The deposition rates for evaluation examples 1-3 below were calculated using formula 1 below.

[0162] [Mathematics 1] Evaporation rate (Å / cycle) = Evaporation thickness / Number of ALD cycles

[0163] The deposition thickness in Equation 1 above was measured using an ellipsometer and confirmed using a field emission scanning electron microscope (FE-SEM).

[0164] At a process temperature of 430°C, the atomic layer deposition (ALD) process was carried out according to the manufacturing methods of Production Examples 2 and 4. During the process, a first precursor injection time (source feeding time) representing a constant thin film deposition rate was measured to confirm the self-limiting reaction.

[0165] [Evaluation Example 2 - Change in thin film deposition rate due to injection time of the second precursor compound]

[0166] A silicon thin film was produced by varying the injection time of the second precursor compound in Production Example 2 within a range of 5 to 15 seconds under the process conditions described in Table 1, and the deposition rate of the thin film was measured.

[0167] At a process temperature of 430°C, an atomic layer deposition (ALD) process was carried out using the manufacturing method of Production Example 2, with the first precursor compound from Production Example 2 as the source and the second precursor compound as the reactant. During the process, the injection time of the second precursor, which represents a constant thin film deposition rate, was measured to confirm a self-limiting reaction.

[0168] On the other hand, a thin film was produced by varying the second precursor injection time in Production Example 4 within a range of 5 to 15 seconds under the process conditions described in Table 1, and the deposition rate of the thin film was measured.

[0169] At a process temperature of 430°C, the atomic layer deposition (ALD) process according to the manufacturing method of Production Example 4 was carried out, using the first precursor compound of Production Example 4 as the source and the second precursor compound as the reactant. During the process, the injection time of the second precursor, which represents a constant thin film deposition rate, was measured to confirm the self-limiting reaction.

[0170] [Evaluation Example 3 - Change in Thin Film Deposition Rate Due to Process Temperature]

[0171] Thin films were manufactured according to the manufacturing examples, with the process temperature varied within the ranges of 400°C to 450°C for manufacturing example 2 and 420°C to 450°C for manufacturing example 4, under the process conditions described in Table 1 above, and the deposition rate of the silicon thin films was measured.

[0172] [Evaluation Example 4 - Grain size analysis of manufacturing example 2 and manufacturing example 4]

[0173] The grain size was analyzed via scanning electron microscopy (SEM) when DIS was used as the first precursor compound and TCDS was used as the second precursor compound in Production Example 2.

[0174] The grain size was analyzed via scanning electron microscopy (SEM) when DIS was used as the first precursor compound and PCDS was used as the second precursor compound in Production Example 4.

[0175] [Evaluation Example 5 - AFM analysis of manufacturing examples 2, 4, 5, or 8]

[0176] The morphology of the thin films was analyzed via atomic force microscopy (AFM) when DIS was used as the first precursor compound and TCDS was used as the second precursor compound in Production Example 2.

[0177] The morphology of thin films produced using DIS as the first precursor compound and PCDS as the second precursor compound in Production Example 4 was analyzed via atomic force microscopy (AFM).

[0178] The morphology of the thin film produced in Production Example 5, in which ammonia (NH3) was used as the third injection step compound in the thin film produced in Production Example 2, was analyzed via atomic force microscopy (AFM).

[0179] The morphology of the thin film produced in Production Example 6, in which ozone (O3) was used as the third injection step compound in the thin film produced in Production Example 2, was analyzed via atomic force microscopy (AFM).

[0180] The morphology of the thin film produced in Production Example 7, in which ammonia (NH3) was used as the third injection step compound in the thin film produced in Production Example 4, was analyzed via atomic force microscopy (AFM).

[0181] The morphology of the thin film produced in Production Example 8, in which ozone (O3) was used as the third injection step compound in the thin film produced in Production Example 4, was analyzed via atomic force microscopy (AFM).

[0182] [Evaluation Example 6 - X-ray diffraction analysis (XRD) of Manufacturing Examples 2, 4, 5, or 8]

[0183] The morphology of the thin films was analyzed via X-ray diffraction when DIS was used as the first precursor compound and TCDS was used as the second precursor compound in Production Example 2.

[0184] The morphology of thin films produced using DIS as the first precursor compound and PCDS as the second precursor compound in Production Example 4 was analyzed by X-ray diffraction.

[0185] The morphology of the thin film produced in Production Example 5, in which ammonia (NH3) was used as the third injection step compound in the thin film produced in Production Example 2, was analyzed by X-ray diffraction analysis.

[0186] The morphology of the thin film of Production Example 6, in which ozone (O3) was used as the third injection step compound in the thin film produced by Production Example 2, was analyzed by X-ray diffraction analysis.

[0187] The morphology of the thin film produced in Production Example 7, in which ammonia (NH3) was used as the third injection step compound in the thin film produced in Production Example 4, was analyzed by X-ray diffraction analysis.

[0188] The morphology of the thin film produced in Production Example 8, in which ozone (O3) was used as the third injection step compound in the thin film produced in Production Example 4, was analyzed by X-ray diffraction analysis.

[0189] Through the thin-film manufacturing process described above, it was confirmed that, using the manufacturing methods employing the first and second precursor compounds of Manufacturing Examples 2 and 4, silicon thin films with excellent properties can be formed by atomic layer deposition even in low-temperature processes below 500°C.

[0190] The scope of this application is expressed more by the claims described below than by the detailed description above, and it should be interpreted that the meaning and scope of the claims, and any modified or altered forms derived from the concept of equivalents thereof, are included in the scope of this application. [Explanation of Symbols]

[0191] 110 First injection step of the first cycle 120 First purge step of the first cycle 130 Second injection step of the first cycle 140 First purge step of the first cycle 150 First cycle repeatability determination step 160 Third injection step 170 The Third Purge Step 180 Silicon seed layer production discontinued. 210 First injection step of the second cycle 220 First purge step of the second cycle 230 Second injection step of the second cycle 240 Second purge step of the second cycle 250 Second cycle repeatability determination step 260 Fourth injection step 270 The Fourth Purge Step 280 Silicon thin film production discontinued.

Claims

1. A first injection step involves injecting a first precursor compound into a chamber, A second injection step involves injecting a second precursor compound into the chamber, The first cycle, which includes the above, is repeated to deposit a thin film. The first precursor compound is represented by the following chemical formula 1, The second precursor compound is represented by the following chemical formula 2, A method for producing a thin film in which the first precursor compound and the second precursor compound are different from each other. [Chemical formula 1] Si(R 1 ) x H (4-x) [Case 2] Yes y (R) 2 ) z H (2y+2-z) In the aforementioned chemical formulas 1 and 2, R 1 and R 2 are each independently any one selected from the group consisting of fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), x is an integer between 1 and 4. If y is 1, then z is an integer from 1 to 4. If y is 2 or 3, then z is an integer from 1 to 6.

2. Between the first injection step and the second injection step, a first purge step is performed in which a first purge gas is injected into the chamber, A second purge step is performed after the second injection step, in which a second purge gas is injected into the chamber, A method for producing a thin film according to claim 1, further comprising:

3. Hydrogen (H) is added to the first injection step, the second injection step, the first purge step, the second purge step, or a combination thereof. 2 A method for manufacturing a thin film according to claim 2, further comprising injecting )

4. The compounds represented by the above chemical formula 1 include fluorosilane, chlorosilane, bromosilane, iodosilane, difluorosilane, dichlorosilane, dibromosilane, diiodosilane, trifluorosilane, trichlorosilane, tribromosilane, triiodosilane, and tetrafluorosilane. A method for producing a thin film according to claim 1, wherein one or more of the following are selected from the group consisting of silane, tetrachlorosilane, tetrabromosilane, and tetraiodosilane.

5. The compounds represented by the above chemical formula 2 include fluorosilane, chlorosilane, bromosilane, iodosilane, difluorosilane, dichlorosilane, dibromosilane, diiodosilane, trifluorosilane, trichlorosilane, tribromosilane, triiodosilane, and tetrafluorosilane. silane, tetrachlorosilane, tetrabromosilane, tetraiodosilane, fluorodisilane, chlorodisilane, bromodisilane, iododisilane, difluorodisilane, dichlorodisilane, dibromodisilane, dibromodisilane, diiododisilane, trifluorodisilane disilane), trichlorodisilane, tribromodisilane, triiododisilane, tetrafluorodisilane, tetrachlorodisilane, tetrabromodisilane, tetraiododisilane, pentafluorodisilane, pentachlorodisilane, pentabromodisilanedisilane), pentaiododisilane, hexafluorodisilane, hexachlorodisilane, hexabromodisilane, hexaiododisilane, fluorotrisilane, chlorotrisilane, bromotrisilane, iodotrisilane, difluorotrisilane, dichlorotrisilane trisilane, dibromotrisilane, diiodotrisilane, trifluorotrisilane, trichlorotrisilane, tribromotrisilane, triiodotrisilane, tetrafluorotrisilane, tetrachlorotrisilane, tetrabromotrisilane, tetrabromotrisilane, tetraiodotrisilane, pentafluorotrisilane A method for producing a thin film according to claim 1, wherein one or more are selected from the group consisting of trisilane, pentachlorotrisilane, pentabromotrisilane, pentaiodotrisilane, hexafluorotrisilane, hexachlorotrisilane, hexabromotrisilane, and hexaiodotrisilane.

6. A method for manufacturing a thin film according to claim 1, wherein the process temperature is 350°C or higher and 500°C or lower.

7. The first cycle is one or more and 70 or less. The method for manufacturing a thin film according to claim 1, wherein the thin film produced by repeating the first cycle is a silicon seed layer.

8. The process further includes a third injection step of injecting a compound containing hydrogen (H), nitrogen (N), oxygen (O), or a combination thereof into the chamber, The method for producing a thin film according to claim 7, wherein the silicon seed layer is nitrided or oxidized.

9. A method for manufacturing a thin film according to claim 8, further comprising a third purging step of injecting a third purge gas into the chamber after the third injection step.

10. A silicon thin film is formed by further repeating a second cycle which includes a first injection step of injecting the first precursor compound onto the silicon seed layer and a second injection step of injecting the second precursor compound. The method for manufacturing a thin film according to any one of claims 7 to 9, wherein the silicon thin film formed on the silicon seed layer is in an amorphous state, a state in which an amorphous state and a nanocrystalline state are mixed, and a nanocrystalline state.

11. The method for manufacturing a thin film according to claim 10, wherein the silicon thin film is nitrided or oxidized.

12. The method for producing a thin film according to claim 10, further comprising a fourth injection step of injecting a compound containing hydrogen (H), nitrogen (N), oxygen (O), or a combination thereof into the chamber.

13. A method for manufacturing a thin film according to claim 12, further comprising a fourth purging step of injecting a fourth purging gas into the chamber after the fourth injection step.

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