Method for forming thin films using two 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 through atomic layer deposition (ALD) even at low temperatures using two silicon precursors. [Background technology]

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

[0003] Representative well-known techniques for manufacturing silicon-containing thin films include atomic layer deposition (ALD), in which a gaseous precursor is physically or chemically adsorbed on a substrate surface and then a reactant gas is sequentially introduced to form a film; and metalorganic chemical vapor deposition (MOCVD), in which a mixed gaseous organometallic precursor and a reactant gas react to form a film on the substrate surface, or react directly on the surface to form a film. Various thin film manufacturing technologies, such as low-pressure chemical vapor deposition (LPCVD), plasma-assisted chemical vapor deposition (PECVD), which allows deposition at low temperatures, and atomic layer deposition (PEALD), which are applied to device manufacturing processes such as next-generation semiconductors, are used to form ultrafine patterns and deposit thin films with uniformity and excellent properties at nanometer-level thicknesses.

[0004] In particular, thin films used in semiconductor devices must be controllable at the atomic level and possess excellent step coverage. Atomic layer deposition (ALD) is a technology that can achieve this. The development of a highly isotropic thin film deposition method that allows for nanoscale thickness control is crucial, and ALD is gaining attention as the most promising deposition technology for many nanoscale device applications. ALD is expected to solve problems caused by device miniaturization, such as high leakage current. In addition to depositing a single high-k material, ALD also has the added advantage of being able to deposit thin films with atomic-level compositional variations. The principle of ALD is to deposit one atomic layer by supplying reactants separated by an inert gas (e.g., Ar, N2) onto a wafer, and then repeat the process to deposit the desired thickness. One reactant undergoes chemisorption on the substrate where the thin film is to be deposited. A second or third gas is then introduced, and a thin film is formed by the subsequent chemisorption on the substrate. The reactants used may be simple elements or compounds, and such reactants must be highly volatile, stable substances, and highly reactive.

[0005] However, when using precursors used in existing atomic layer deposition methods, high-temperature processes of 600°C or higher are required. At the same time, the high-temperature processes cause the reactants to decompose, resulting in defects, which can lead to deterioration in the physical and electrical properties of the thin film, such as step coverage and etching characteristics.

[0006] This has led to an increasing need for a deposition process that has low temperature behavior, thin film adhesion, excellent step coverage, and thickness control at the atomic layer level.

[0007] As a result, there is a need to develop a method for manufacturing a thin film that is capable of atomic layer deposition even at low temperatures, has excellent step coverage, and is excellent in thin film properties. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Korean Patent Registration No. 10-1436564 Summary of the Invention [Problem to be solved by the invention]

[0009] The present application aims to provide a method for efficiently producing a thin film at a low temperature using two silicon precursors, and a thin film with excellent properties produced by this method.

[0010] In particular, the existing silicon thin film deposition method is a low pressure chemical vapor deposition (LPCVD) method, which forms a silicon thin film containing defects, and therefore, during high temperature crystallization, a polycrystalline silicon (poly-Si) thin film with small grain boundary size is formed.

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

[0012] However, the problems to be solved by the present application are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

[0013] However, the problems that the present invention aims to solve are not limited to those mentioned above, and other problems that are not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the contents that will be described hereinafter. [Means for solving the problem]

[0014] a first injection step of injecting a first precursor compound into the chamber;

[0015] repeating the first cycle, including a second injection step of injecting a second precursor compound into the chamber, to deposit a thin film;

[0016] The first precursor compound is represented by the following chemical formula 1:

[0017] The second precursor compound is represented by the following chemical formula 2:

[0018] Thin film manufacturing method.

[0019] [C1] Si(R1) x H (4-x)

[0020] [C2] Si y (R2) z H (2y+2-z)

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

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

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

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

[0025] When y is 2 or 3, z is an integer of 0 to 6. [Effects of the Invention]

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

[0027] Specifically, the present invention enables atomic layer deposition (ALD) at low temperatures of 500°C or less by introducing two types of silicon precursor compounds. The precursor compounds are used as a source and a reactant, and depending on the type of precursor compound, amorphous or nanocrystalline thin films can be deposited.

[0028] In particular, an amorphous silicon thin film can be deposited and then crystallized to produce a polycrystalline silicon thin film with a large grain boundary size.

[0029] That is, the thin film manufacturing method of the present application uses two types of silicon precursor compounds, making it possible to deposit a uniform thin film with excellent properties even at low temperatures, thereby ensuring excellent thin film properties, thickness, and step coverage, and also enabling the morphology and crystallinity of the deposited thin film to be controlled.

[0030] Furthermore, the thin film having excellent properties manufactured by the method for manufacturing a thin film of the present invention can be used for dielectrics of various electronic devices, displays, next-generation memories, non-memory semiconductors, etc. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a schematic diagram illustrating a process for forming a silicon seed layer and oxidizing or nitriding the silicon seed layer. [Figure 2] 1 is a schematic diagram illustrating a process for manufacturing a silicon thin film and oxidizing or nitriding the silicon thin film. DETAILED DESCRIPTION OF THE INVENTION

[0032] The functions and effects of the present invention will be described in more detail below with reference to specific embodiments and drawings of the present invention, however, these embodiments are presented only as examples of the present invention and do not define the scope of the invention.

[0033] Prior to this, the terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts that are consistent with the technical idea of ​​the present invention, based on the principle that an inventor can appropriately define the concept of a term in order to explain his or her invention in the best possible way.

[0034] Therefore, it should be understood that the configuration of the embodiment described in this specification is merely one of the most preferred embodiments of the present invention and does not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can replace them at the time of this application.

[0035] In this specification, the singular includes the plural unless the context clearly dictates otherwise. In this application, the terms "comprises," "comprises," or "having" are intended to specify the presence of embodied features, numbers, steps, components, or combinations thereof, and should be understood as not precluding the presence or additional possibility of one or more other features, numbers, steps, components, or combinations thereof.

[0036] When various parameters are given herein as ranges, preferred ranges, or lists of upper and lower preferred values, it should be understood that all ranges formed by any pair of any upper range limit or preferred value and any lower range limit or preferred value are specifically disclosed, regardless of whether ranges are otherwise disclosed.

[0037] Where a range of numerical values ​​is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range.

[0038] It is not intended that the scope of the invention be limited to the specific values ​​recited when defining a range.

[0039] In this specification, when expressing a numerical range, "a to b" and "a~b", "to" and "to" are defined as ≧a and ≦b.

[0040] A method for producing a thin film according to one aspect of the present application may include depositing a thin film by repeating 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, wherein the first precursor compound is represented by Chemical Formula 1 below, and the second precursor compound is represented by Chemical Formula 2 below.

[0041] [C1] Si(R1) x H (4-x)

[0042] [C2] 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 fluoro (F), chlorine (Cl), bromine (Br), and iodine (I);

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

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

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

[0048] In this case, if the number after an atom is 0, it can mean that the atom is not included.

[0049] Additionally, the formula 2 may or may not be the same as the formula 1.

[0050] In the present application, the term "chamber" may refer to the internal space of a reaction chamber where a thin film deposition process is performed.

[0051] The first cycle may be 1 or more and 1,000 or less, for example, 50 or more, 100 or more, 200 or more, 300 or more, 400 or more, or 500 or more.

[0052] In one embodiment of the present application, 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 application, R2 in the above 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 a low process temperature of 500° C. or less, and the morphology of the deposited thin film may be deteriorated.

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

[0058] Atomic layer deposition (ALD) is a deposition method that involves repeatedly adsorbing a precursor onto a substrate, purging the remaining precursor with a purge gas, reacting with a reactant gas, and then purging the remaining reactant gas with a purge gas. ALD allows for the formation of thinner films with high uniformity. Furthermore, by repeating each step of ALD, a thin film can be formed on a substrate to a desired thickness.

[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. During one cycle of deposition, a monolayer or smaller thin film is grown through a surface reaction. Ligands of reactants adsorbed on the substrate can be removed through chemical reactions with other reactants that are subsequently supplied. When precursor compounds, which are reactants for atomic layer deposition, are heated, the liquid phase offers greater advantages in terms of reaction rate and process than the solid phase.

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

[0061] In one implementation example of the present application, the method may further include a first purge step of injecting a first purge gas into the chamber 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] At this time, the first and second purge gases may each independently be hydrogen (H2), argon (Ar), nitrogen (N2), helium (He), a rare gas, an inert gas, or a combination thereof.

[0063] In one embodiment of the present application, 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 adjust the impurity concentration of halogen atoms.

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

[0065] In one embodiment of the present application, the compound represented by Chemical Formula 1 may be any 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 Chemical Formula 1 may be, but is not limited to, diiodosilane (DIS).

[0067] In one embodiment of the present 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 disilane, tetraiododisilane, pentafluorodisilanedisilane, pentachlorodisilane (PCDS, Si2Cl5H), pentabromodisilane, pentaiododisilane, hexafluorodisilane, hexachlorodisilane, hexabromodisilane, hexaiododisilane, trisilane (trisilane, Si3H8), fluorotrisilane, chlorotrisilane, bromotrisilane, iodotrisilane, difluorotrisilane, dichlorotrisilane, dibromotrisilane trisilane, diiodotrisilane, trifluorotrisilane, trichlorotrisilane, tribromotrisilane, triiodotrisilane, tetrafluorotrisilane, tetrachlorotrisilane, tetrabromotrisilane, tetraiodotrisilane, pentafluorotrisilane, pentachlorotrisilane, pentabromotrisilane, pentaiodotrisilane, hexafluorotrisilane, hexachlorotrisilane trisilane, hexabromotrisilaneThe compound may be any one or more selected from the group consisting of hexaiodotrisilane, hexaiodotrisilane, and hexaiodotrisilane.

[0068] For example, the compound represented by 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 application, the process temperature in the thin film manufacturing method may be 350° C. or higher and 500° C. or lower.

[0070] For example, the process temperature may 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, 350°C or higher and 480°C or lower The temperature may be 350°C or higher and 470°C or lower, 350°C or higher and 460°C or lower, 350°C or higher and 450°C or lower, 350°C or higher and 440°C or lower, 350°C or higher and 430°C or lower, 350°C or higher and 420°C or lower, 350°C or higher and 410°C or lower, 350°C or higher and 400°C or lower, 360°C or higher and 450°C or lower, 370°C or higher and 450°C or lower, 380°C or higher and 450°C or lower, 390°C or higher and 450°C or lower, 400°C or higher and 450°C or lower, 410°C or higher and 450°C or lower, 420°C or higher and 450°C or lower, 430°C or higher and 450°C or lower, or 440°C or higher and 450°C or lower.

[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 producing thin films according to the present invention at temperatures below 350°C, deposition may not be performed properly because the reaction rate may be insufficient, resulting in a slower deposition rate. Furthermore, the second precursor compound may not be sufficiently diffused, which may result in defects and uniformity problems in the material and thin film, leading to instability of the substrate and thin film.

[0073] Furthermore, when a thin film according to the present invention is produced at a temperature exceeding 500°C, deposition may not be performed properly because the reaction rate may be too fast, which may result in the generation of impurities, or the precursor or reaction gas may be decomposed, making it difficult to form a thin film.

[0074] In one embodiment, when the first precursor compound is diiodosilane and the second precursor compound is tetrachlorodisilane, the thin film deposition rate (GPC growth rate per cycle) of the above manufacturing method may be 0.1 to 0.3 Å / cycle at a process temperature of 400 to 450°C. That is, the thin film deposition rate according to the manufacturing method at 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 embodiment, when the first precursor compound is diiodosilane and the second precursor compound is pentachlorodisilane, the thin film deposition rate of the manufacturing method may be 0.1 to 0.3 Å / cycle at a process temperature range of 420 to 450° C. That is, the thin film deposition rate of the manufacturing method at a process temperature range of 420 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.

[0076] In one implementation, the temperature of the canister of the first precursor compound may be between 0°C and 50°C.

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

[0078] The canister temperature of the second precursor compound may be 0°C or higher and 30°C or lower.

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

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

[0081] If the temperature of the canister is outside this range, the thickness uniformity of the thin film manufactured through the thin film manufacturing method may be significantly reduced.

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

[0083] In one embodiment, the injection time of the first precursor compound may be from 1 to 30 seconds, and the injection time of the second precursor compound may be from 1 to 30 seconds, and preferably, the injection time of the first precursor compound may be from 1 to 15 seconds, and the injection time of the second precursor compound may be from 1 to 15 seconds.

[0084] For example, the injection time of the 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, or 1 second to 5 seconds,

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

[0086] If the injection time of the first precursor compound and the second precursor compound is longer or shorter than the above-mentioned time, 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 above range, the reactants required for forming the thin film may be insufficient, resulting in an insufficient thin film thickness.On the other hand, if the injection time of the first precursor compound is more than the above range, the composition ratio of the thin film formed after the reaction may be inconsistent due to impurities from residual compounds.

[0088] In addition, the injection time of the second precursor compound may vary depending on the type of the first precursor compound.

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

[0090] If the injection time of the second precursor compound is less than 1 second, the remaining amount of the first precursor compound as a reactant may increase, causing an inappropriate reaction, and impurities may be generated, resulting in non-uniform deposition of the thin film layer.On the other hand, if the injection time of the second precursor compound is more than 30 seconds, impurities due to the second precursor compound may be generated.

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

[0092] In one embodiment, 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 from 1 second to 60 seconds, from 1 second to 50 seconds, from 1 second to 40 seconds, from 1 second to 30 seconds, from 1 second to 20 seconds, from 1 second to 15 seconds, or from 1 second to 10 seconds.

[0094] If the injection time of the first or second purge gas is less than the above range, the amount of the first or second precursor compound remaining may increase, causing an inappropriate reaction, and impurities may not be purged, resulting in non-uniform deposition of the thin film layer.

[0095] In one embodiment, the thin film produced by repeating the first cycle at least once and no more than 70 times may be a silicon seed layer. In this case, the silicon seed layer may form nucleation islands, and the nucleation islands may be formed randomly.

[0096] Furthermore, if a film is further formed after the nucleation island is 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] FIG. 1 shows the order of the first injection step, the first purge step, the second injection step, and the second purge step in the first cycle.

[0099] In one implementation, after forming the silicon seed layer, the method may further include a third implantation step of implanting a compound containing hydrogen (H), nitrogen (N), oxygen (O), or a combination thereof into the chamber.

[0100] The respective orders of the third implantation step and the third purge step are shown in Figure 1. The third implantation step and the third purge step may be performed optionally if nitridation or oxidation of the silicon seed layer is required. If the third implantation step and the third purge step are not performed, the third implantation step (160) and the third purge step (170) in Figure 1 may be omitted and the process may be terminated (180).

[0101] The compound of the third implantation step may specifically mean hydrogen (H), nitrogen (N), ammonia (NH), oxygen (O), ozone (O), or a combination thereof, and if the third implantation step is further included, 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, after the third injection step, a third purge gas may be injected into the chamber, and the third purge gas may be hydrogen (H), argon (Ar), nitrogen (N), helium (He), a noble gas, an inert gas, or a combination thereof.

[0104] In one embodiment, 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 above range, the remaining amount of the compound injected in the third injection step may increase, causing an inappropriate reaction, and impurities may not be purged, resulting in non-uniform deposition of the thin film layer.

[0106] In one implementation, after forming the silicon seed layer, a second cycle including 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 may be further repeated to form a silicon thin film.

[0107] That is, it can mean that the silicon thin film can be formed by further repeating the second cycle after the first cycle is repeated 1 to 70 times.

[0108] The second cycle may be repeated 1 or more times and 500 or less times, for example, 400 or less times, 300 or less times, 200 or less times, or 100 or less times.

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

[0110] FIG. 2 shows the order of the first injection step, the first purge step, the second injection step, and the second purge step in the second cycle.

[0111] In one embodiment, the silicon thin film formed on the silicon seed layer may be in any one of an amorphous state, a mixed state of an amorphous state and a nanocrystalline state, and a nanocrystalline state.

[0112] Generally, atomic layer deposition processes result in atoms or molecules arranged randomly without any regular pattern, which typically occurs during fast cooling or certain chemical processes when there is insufficient time for crystalline structures to form.

[0113] Amorphous thin films can be produced by atomic layer deposition, and materials in this state generally have consistent thermal, mechanical, and electrical properties depending on the direction.

[0114] Nanocrystalline refers to materials with a crystalline structure on a nanometer scale. Nanocrystals have unique physical properties due to their minute size and high surface-to-volume ratio. Materials in this state can exhibit different electrical, optical, and mechanical properties from amorphous materials. Nanocrystalline thin films can be manufactured through atomic layer deposition.

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

[0116] In the present invention, the surface morphology of the thin film can be adjusted by the types of the first precursor compound and the second precursor compound.

[0117] Furthermore, according to the manufacturing method of the present invention, a thin film in a nanocrystalline state and a mixed state of an amorphous state and a nanocrystalline state can be obtained without additional heat treatment after deposition.

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

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

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

[0121] In one embodiment, a crystallized silicon thin film can be formed by further performing a heat treatment on the 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 (H) in the first injection step, the second injection step, the third injection step, the first purge step, the second purge step, the third purge step, the fourth injection step, the fourth purge 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 embodiment, the roughness of the thin film manufactured by the manufacturing method may be measured by AFM, with an Rq value of 0.1 nm to 0.5 nm at a scan size of 5 μm.

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

[0125] In one embodiment, the roughness of the thin film manufactured by the manufacturing method may be measured by AFM with 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 0.1 nm or more and 0.4 nm or less, 0.12 nm or more and 0.35 nm or less, 0.14 nm or more and 0.3 nm or less, 0.15 nm or more and 0.29 nm or less, 0.17 nm or more and 0.28 nm or less, 0.17 nm or more and 0.3 nm or less, 0.17 nm or more and 0.35 nm or less, 0.17 nm or more and 0.4 nm or less, 0.2 nm or more and 0.4 nm or less, 0.21 nm or more and 0.39 nm or less, 0.22 nm or more and 0.38 nm or less, 0.23 nm or more and 0.36 nm or less, or 0.24 nm or more and 0.35 nm or less.

[0127] In one implementation, after forming the silicon, a fourth implantation step can be further included in which a compound containing hydrogen (H), nitrogen (N), oxygen (O), or a combination thereof is implanted into the chamber. The compound of the fourth implantation step can specifically mean hydrogen (H), nitrogen (N), ammonia (NH), oxygen (O), ozone (O), or a combination thereof. When the third implantation step is further included, the silicon seed layer can 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, after the fourth injecting step, a fourth purge gas can be injected into the chamber, where the fourth purge gas can be hydrogen (H), argon (Ar), nitrogen (N), helium (He), a noble gas, an inert gas, or a combination thereof.

[0130] The respective orders of the fourth injection step and the fourth purge step are shown in FIG. 2. The fourth injection step and the fourth purge step can be selectively performed if nitridation 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 FIG. 2 can be omitted and the process can be terminated (280).

[0131] In one embodiment, 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 above range, the remaining amount of the compound injected in the fourth injection step may increase, causing an inappropriate reaction, and impurities may not be purged, resulting in non-uniform deposition of the thin film layer.

[0133] The present invention will be described in more detail below using production examples, but the present invention is not limited thereto.

[0134] [Manufacturing example]

[0135] A thin film was produced using the first precursor compound and the second precursor compound using atomic layer deposition (ALD) equipment.

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

[0137] 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 of the first precursor compound was maintained at 25°C in Preparation 1 and 5°C in Preparation 2.

[0140] The first precursor compound, argon (Ar), the second precursor compound, and argon (Ar) were supplied in this order, completing one cycle.

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

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

[0143] The injection time of the second precursor compound used in Preparation Examples 1 and 2 was adjusted to 5 to 15 seconds, and the injection rate of the second precursor compound was 100 sccm, and the process pressure was 3.0 to 4.0 torr.

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

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

[0146] The injection time of the second precursor compound used in Preparation Examples 3 and 4 was adjusted to 5 to 15 seconds, the injection amount of the second precursor compound was 100 sccm, and the process pressure was 3.0 to 4.0 torr.

[0147] That is, in Production Examples 1 and 3, the third injection step and the third purge step in FIG. 1 were not performed, and the first injection step, the first purge step, the second injection step, and the second purge step were repeated in sequence 70 times to produce a silicon seed layer.

[0148] In addition, in Preparation Examples 2 and 4, unlike Preparation Examples 1 and 3, the third injection step and third purge step in FIG. 1 were not performed, and instead the first injection step, first purge step, second injection step, and second purge step were repeated in sequence 70 times to produce a silicon seed layer, and then the first injection step, first purge step, second injection step, and second purge step in FIG. 2 were repeated in sequence 110 times and 130 times, respectively, to produce a silicon thin film on the silicon seed layer.

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

[0150] [Table 1]

[0151] In Table 1, DIS stands for diiodosilane, TCDS stands for tetrachlorodisilane, and PCDS stands for pentachlorodisilane.

[0152] In Preparation Example 5, ammonia (NH3)-argon (Ar) were further supplied in this order to the silicon thin film prepared in Preparation Example 2.

[0153] In Preparation Example 6, ozone (O3) and argon (Ar) were further supplied in sequence to the silicon thin film prepared in Preparation Example 2.

[0154] In Production Example 7, ammonia (NH3)-argon (Ar) were further supplied in this order to the silicon thin film produced in Production Example 4.

[0155] In Preparation Example 8, ozone (O3) and argon (Ar) were further supplied in sequence to the silicon thin film prepared in Preparation Example 4.

[0156] That is, in Production Examples 5 to 8, the silicon thin films produced in Production Examples 2 and 4 were further subjected to the fourth injection step and fourth purge step of FIG. 2 to oxidize or nitride the silicon thin films.

[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 depending on injection time of first precursor compound]

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

[0161] The deposition rates of Evaluation Examples 1 to 3 were calculated using the following formula 1.

[0162] [Number 1] Deposition rate (Å / cycle) = deposition thickness / number of ALD cycles

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

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

[0165] [Evaluation Example 2 - Change in thin film deposition rate depending on injection time of second precursor compound]

[0166] Under the process conditions listed in Table 1, the injection time of the second precursor compound of Preparation Example 2 was varied within a range of 5 to 15 seconds to prepare a silicon thin film according to Preparation Example 2, and the deposition rate of the thin film was measured.

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

[0168] Meanwhile, under the process conditions shown in Table 1, thin films were prepared according to Preparation Example 4 by varying the injection time of the second precursor in the range of 5 to 15 seconds, and the deposition rate of the thin films was measured.

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

[0170] [Evaluation Example 3 - Change in thin film deposition rate depending on process temperature]

[0171] Under the process conditions listed in Table 1, thin films were manufactured according to the above Preparation Examples while varying the process temperature within the range of 400°C to 450°C in Preparation Example 2 and 420°C to 450°C in Preparation Example 4, and the deposition rate of the silicon thin film was measured.

[0172] [Evaluation Example 4 - Analysis of Grain Size in Preparation Examples 2 and 4]

[0173] In Preparation Example 2, when DIS was used as the first precursor compound and TCDS was used as the second precursor compound, the grain size was analyzed using a scanning electron microscope (SEM).

[0174] In Preparation Example 4, when DIS was used as the first precursor compound and PCDS was used as the second precursor compound, the grain size was analyzed using a scanning electron microscope (SEM).

[0175] [Evaluation Example 5 - AFM analysis of Production Examples 2, 4, 5, and 8]

[0176] The morphology of the thin film obtained when DIS was used as the first precursor compound and TCDS was used as the second precursor compound in Preparation Example 2 was analyzed using an atomic force microscope (AFM).

[0177] The morphology of a thin film prepared using DIS as the first precursor compound and PCDS as the second precursor compound in Preparation Example 4 was analyzed using an atomic force microscope (AFM).

[0178] The morphology of the thin film of Preparation Example 5, in which ammonia (NH3) was used as the third injection step compound in the thin film prepared in Preparation Example 2, was analyzed using an atomic force microscope (AFM).

[0179] The morphology of the thin film of Preparation Example 6, in which ozone (O3) was used as the compound in the third injection step on the thin film prepared in Preparation Example 2, was analyzed using an atomic force microscope (AFM).

[0180] The morphology of the thin film of Preparation Example 7, in which ammonia (NH3) was used as the third injection step compound in the thin film prepared in Preparation Example 4, was analyzed using an atomic force microscope (AFM).

[0181] The morphology of the thin film of Preparation Example 8, in which ozone (O3) was used as the compound in the third injection step on the thin film prepared in Preparation Example 4, was analyzed using an atomic force microscope (AFM).

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

[0183] The morphology of the thin film obtained when DIS was used as the first precursor compound and TCDS was used as the second precursor compound in Preparation Example 2 was analyzed by X-ray diffraction analysis.

[0184] The morphology of a thin film prepared using DIS as the first precursor compound and PCDS as the second precursor compound in Preparation Example 4 was analyzed by X-ray diffraction analysis.

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

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

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

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

[0189] Through the above thin film manufacturing process, it was confirmed that the manufacturing methods using the first precursor compound and the second precursor compound of Manufacturing Examples 2 and 4 can form silicon thin films with excellent properties by atomic layer deposition even at low temperatures of 500°C or less.

[0190] The scope of the present application is represented by the claims set forth below rather than the above detailed description, and all modifications or variations derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present application. [Explanation of symbols]

[0191] 110 First injection step of first cycle 120 First purge step of first cycle 130 Second injection step of first cycle 140 First purge step of first cycle 150 First cycle repeat decision step 160 Third injection step 170 Third Purge Step 180 Silicon seed layer production completed 210 First injection step of second cycle 220 First purge step of second cycle 230 Second injection step of second cycle 240 Second purge step of second cycle 250 Decision step for whether to repeat the second cycle 260 Fourth injection step 270 Fourth Purge Step 280 End of silicon thin film production

Claims

1. a first injection step of injecting a first precursor compound into the chamber; a second injection step of injecting a second precursor compound into the chamber; repeating a first cycle comprising: The first precursor compound is represented by the following chemical formula 1: The second precursor compound is represented by the following chemical formula 2: [Chemical formula 1] Si(R 1 ) x H (4-x) [Chemical 2] Yes y (R) 2 ) z H (2y+2-z) In the above Chemical Formulas 1 and 2, R 1 and R 2 are each independently any one selected from the group consisting of fluoro (F), chlorine (Cl), bromine (Br), and iodine (I); x is an integer from 1 to 4, when y is 1, z is an integer from 0 to 4; When y is 2 or 3, z is an integer from 0 to 6.

2. a first purge step of injecting a first purge gas into the chamber between the first injection step and the second injection step; a second purge step of injecting a second purge gas into the chamber after the second injection step; The method for producing a thin film according to claim 1 , further comprising:

3. The first injection step, the second injection step, the first purge step, the second purge step, or a combination thereof may include hydrogen (H 2 3. The method for producing a thin film according to claim 2, further comprising the step of:

4. The compound represented by Chemical Formula 1 includes fluorosilane, chlorosilane, bromosilane, iodosilane, difluorosilane, dichlorosilane, dibromosilane, diiodosilane, trifluorosilane, trichlorosilane, tribromosilane, triiodosilane, and tetrafluorosilane.

2. The method of claim 1, wherein the silane is at least one selected from the group consisting of tetrachlorosilane, tetrabromosilane, and tetraiodosilane.

5. The compound represented by Formula 2 is a silane (SiH 4 , fluorosilane, chlorosilane, bromosilane, iodosilane, difluorosilane, dichlorosilane, dibromosilane, diiodosilane, trifluorosilane, trichlorosilane, tribromosilane, triiodosilane, tetrafluorosilane, tetrachlorosilane silane), tetrabromo silane, tetraiodo silane, disilane (Si 2 H 6 ), fluorodisilane, chlorodisilane, bromodisilane, iododisilane, difluorodisilane, dichlorodisilane, dibromodisilane, diiododisilane, trifluorodisilane, trichlorodisilane, tribromodisilane, triiododisilane disilane), tetrafluorodisilane, tetrachlorodisilane, tetrabromodisilane, tetraiododisilane, pentafluorodisilane, pentachlorodisilane, pentabromodisilane, pentaiododisilane, hexafluorodisilane, hexachlorodisilane disilane), hexabromo disilane, hexaiodo disilane, trisilane (Si 3 H 8 ), fluorotrisilane, chlorotrisilane, bromotrisilane, iodotrisilane, difluorotrisilane, dichlorotrisilane, dibromotrisilane, diiodotrisilane, trifluorotrisilane, trichlorotrisilane, tribromotrisilane, triiodotrisilane trisilane), tetrafluorotrisilane, tetrachlorotrisilane, tetrabromotrisilane, tetraiodotrisilane, pentafluorotrisilane, pentachlorotrisilane, pentabromotrisilane, pentaiodotrisilane, hexafluorotrisilane, hexachlorotrisilane 2. The method for producing a thin film according to claim 1, wherein the compound is at least one selected from the group consisting of hexabromotrisilane, hexabromotrisilane, and hexaiodotrisilane.

6. 2. The method for producing 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 1 to 70 times, 2. The method of claim 1, wherein the thin film produced by repeating the first cycle is a silicon seed layer.

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

10. further repeating a second cycle including 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 onto the silicon seed layer to form a silicon thin film; 10. The method of claim 7, wherein the silicon thin film formed on the silicon seed layer is in one of an amorphous state, a mixed state of an amorphous state and a nanocrystalline state, and a nanocrystalline state.

11. The method for producing 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. The method for producing a thin film according to claim 12, further comprising a fourth purge step of injecting a fourth purge gas into the chamber after the fourth injection step.

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