Superlattice-structured IGZO material film and manufacturing method therefor

Abstract

A method for manufacturing an IGZO material film is provided. The method for manufacturing an IGZO material film may comprise the steps of: preparing a substrate; performing a first unit process of reacting an indium (In) precursor and a first reactant on the substrate so as to form a first material layer including indium oxide; performing a second unit process of reacting a gallium (Ga) precursor and a second reactant on the first material layer so as to form a second material layer including gallium oxide; performing a third unit process of reacting a zinc (Zn) precursor and a third reactant on the second material layer so as to form a third material layer including zinc oxide; and heat-treating an IGZO material film in which the first to third material layers are stacked, so as to form the IGZO material film into a superlattice structure.

Description

IGZO material film with superlattice structure and method for manufacturing the same

[0001] The present invention relates to an IGZO material film with a superlattice structure and a method for manufacturing the same.

[0002] IGZO is attracting attention as a next-generation semiconductor material capable of replacing silicon due to its ultra-low power characteristics and the possibility of uniform deposition in three-dimensional structures. Initially, single-crystal superlattice IGZO (mobility ~80 cm²) 2 Although / Vs) was developed, due to limitations such as high-temperature processes (above 1400℃) and the requirement for a seed layer, amorphous IGZO (a-IGZO, mobility ~10cm²) was used in large-area and 3D processes. 2 / Vs) has been primarily used. Amorphous IGZO has the advantage of enabling uniform deposition and low-temperature processing, and is widely utilized in the display industry. Subsequently, C-axis Aligned Crystalline (CAAC) IGZO was developed to improve electrical characteristics and stability; while this has improved some electrical performance and reliability, limitations in stability (high temperature and hydrogen), electrical characteristics, and reliability still exist for expanded application in the semiconductor field. Therefore, the present invention aims to provide a method for manufacturing a superlattice structured IGZO with high stability, electrical characteristics, and reliability at a low temperature (800°C) without a seed layer.

[0003] The technical problem that the present invention aims to solve is to provide an IGZO material film with a superlattice structure and a method for manufacturing the same.

[0004] Another technical problem that the present invention aims to solve is to provide an IGZO material film and a method for manufacturing such that a superlattice structure can be formed even at a low temperature heat treatment of 800°C.

[0005] Another technical problem that the present invention aims to solve is to provide an IGZO material film in which a superlattice structure can be formed without a separate seed layer, and a method for manufacturing the same.

[0006] The technical problems that the present invention aims to solve are not limited to those described above.

[0007] To solve the technical problems described above, the present invention provides a method for manufacturing an IGZO material film.

[0008] According to one embodiment, the method for manufacturing the IGZO material film may include the steps of: preparing a substrate; performing a first unit process of reacting an indium (In) precursor and a first reactant on the substrate to form a first material layer containing indium oxide; performing a second unit process of reacting a gallium (Ga) precursor and a second reactant on the first material layer to form a second material layer containing gallium oxide; performing a third unit process of reacting a zinc (Zn) precursor and a third reactant on the second material layer to form a third material layer containing zinc oxide; and heat-treating the IGZO material film having the first to third material layers stacked thereon to form the IGZO material film into a superlattice structure.

[0009] According to one embodiment, the IGZO material film may be formed into a superlattice structure at a heat treatment temperature of 800°C.

[0010] According to one embodiment, the number of repetitions of the first unit process: the second unit process: the third unit process may be controlled to 12:4:4.

[0011] According to one embodiment, the first unit process may be repeated 12 times, after which the second unit process and the third unit process are alternately repeated 4 times each.

[0012] According to one embodiment, the first material layer may be formed with a thickness of more than 0.5 nm and less than 3 nm.

[0013] According to one embodiment, the first material layer may have an amorphous structure.

[0014] According to one embodiment, when the IGZO material film is heat-treated, the IGZO material film may be formed into a superlattice structure after the first material layer is crystallized.

[0015] According to one embodiment, when the IGZO material film is heat-treated, the first material layer may be crystallized into a bixbyite structure.

[0016]

[0017] To solve the technical problems described above, the present invention provides an IGZO material film.

[0018] According to one embodiment, the IGZO material film may comprise indium (In), gallium (Ga), zinc (Zn), and oxygen (O), and may have a superlattice structure aligned in the C-axis direction.

[0019] According to one embodiment, the IGZO material film may include peaks (0003), (0006), and (0009) observed in the GIWAXS analysis results.

[0020] According to one embodiment, the IGZO material film may include a GIWAXS analysis result in which peaks (222), (121), (112), (222), and (040) are not observed.

[0021] According to one embodiment, the IGZO material film may include a crystal plane spacing (d-spacing) of 0.88 nm to 0.93 nm as confirmed by HRTEM analysis results (0003).

[0022] According to one embodiment, the IGZO material film may include a crystal plane (111) and a crystal plane (400) that are not identified as a result of HRTEM analysis.

[0023] According to the present invention, an IGZO material film with a superlattice structure can be easily formed even at a low temperature heat treatment of 800°C, and since a separate seed layer for forming the superlattice structure is not required, it can be formed on various substrates. Accordingly, it can be easily applied to various structures such as 3D NAND, GAA, and CAA structures.

[0024] FIG. 1 is a flowchart illustrating a method for manufacturing an IGZO material film according to an embodiment of the present invention.

[0025] FIG. 2 is a diagram for explaining the process sequence of an IGZO material film according to an embodiment of the present invention in more detail.

[0026] FIGS. 3 and 4 are drawings for explaining an IGZO material film according to an embodiment of the present invention.

[0027] FIG. 5 is a diagram illustrating the composition ratio of IGZO material films according to Experimental Examples 1 to 4 of the present invention.

[0028] FIG. 6 is a diagram illustrating the film growth rate, refractive index, and uniformity of IGZO material films according to Experimental Examples 1 to 4 of the present invention.

[0029] Figure 7 is a TEM image of an IGZO material film according to Experimental Example 1 of the present invention.

[0030] Figure 8 is a TEM image of an IGZO material film according to Experimental Example 4 of the present invention.

[0031] FIG. 9 is a diagram illustrating the XRD analysis results for the state of the IGZO material film before heat treatment according to Experimental Examples 1 to 4 of the present invention.

[0032] FIG. 10 is a diagram illustrating the XRD analysis results for an IGZO material film according to Experimental Examples 1 to 4 of the present invention that has been heat-treated at a temperature of 400°C.

[0033] FIG. 11 is a diagram illustrating the XRD analysis results for an IGZO material film according to Experimental Examples 1 to 4 of the present invention that has been heat-treated at a temperature of 600°C.

[0034] FIG. 12 is a diagram illustrating the XRD analysis results for an IGZO material film according to Experimental Examples 1 to 4 of the present invention that has been heat-treated at a temperature of 800°C.

[0035] FIG. 13 is a diagram illustrating the GIWAXS analysis results for an IGZO material film according to Experimental Example 1 of the present invention that has been heat-treated at a temperature of 800°C.

[0036] Figure 14 is a diagram illustrating the GIWAXS analysis results for an IGZO material film according to Experimental Example 2 of the present invention that has been heat-treated at a temperature of 800°C.

[0037] FIG. 15 is a diagram illustrating the GIWAXS analysis results for an IGZO material film according to Experimental Example 3 of the present invention that has been heat-treated at a temperature of 800°C.

[0038] FIG. 16 is a diagram illustrating the GIWAXS analysis results for an IGZO material film according to Experimental Example 4 of the present invention that has been heat-treated at a temperature of 800°C.

[0039] FIG. 17 is a diagram illustrating the TEM analysis results for an IGZO material film according to Experimental Example 1 of the present invention that has been heat-treated at a temperature of 800°C.

[0040] FIG. 18 is a diagram illustrating the TEM analysis results for an IGZO material film according to Experimental Example 2 of the present invention that has been heat-treated at a temperature of 800°C.

[0041] FIG. 19 is a diagram illustrating the TEM analysis results for an IGZO material film according to Experimental Example 3 of the present invention after heat treatment at a temperature of 800°C.

[0042] FIG. 20 is a diagram illustrating the TEM analysis results for an IGZO material film according to Experimental Example 4 of the present invention after heat treatment at a temperature of 800°C.

[0043] FIG. 21 is a diagram illustrating the phase transition process of an IGZO material film according to Experimental Examples 1 to 4 of the present invention.

[0044] FIG. 22 is a diagram illustrating the change in state of an IGZO material film according to the heat treatment time in Experimental Example 4 of the present invention.

[0045] FIG. 23 is a diagram illustrating the composition ratio of IGZO material films according to Experimental Examples 4 to 7 of the present invention.

[0046] FIG. 24 is a diagram illustrating the crystal state of an IGZO material film according to Experimental Examples 4 to 7 of the present invention.

[0047] FIG. 25 is InO according to Experimental Examples 1 to 3 of the present invention x This is a diagram illustrating the XRD analysis results of a material film.

[0048] FIG. 26 shows InO according to Experimental Examples 1 and 2 of the present invention. x This is a diagram illustrating the HRTEM analysis results of the material film.

[0049] FIG. 27 is a diagram illustrating a transistor according to Experimental Example 4 of the present invention.

[0050] Figure 28 is an image of a transistor according to Experimental Example 4 of the present invention.

[0051] FIG. 29 is a diagram illustrating the current-voltage characteristics of a transistor according to Experimental Example 4 of the present invention.

[0052] FIG. 30 is a diagram illustrating the change in threshold voltage according to the heat treatment of a transistor according to Experimental Example 4 of the present invention.

[0053] FIG. 31 is a diagram illustrating the stress test results of a transistor according to Experimental Example 4 of the present invention.

[0054] FIG. 32 is a diagram illustrating the long-term operational stability of a transistor according to Experimental Example 4 of the present invention.

[0055] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the technical concept of the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to ensure that the concept of the present invention is sufficiently conveyed to those skilled in the art.

[0056] In this specification, when a component is described as being on another component, it means that it may be formed directly on the other component or that a third component may be interposed between them. Additionally, in the drawings, the thicknesses of the films and regions are exaggerated for the effective description of the technical content.

[0057] Additionally, although terms such as first, second, third, etc., have been used to describe various components in the various embodiments of this specification, these components should not be limited by such terms. These terms are used merely to distinguish one component from another. Accordingly, what is referred to as the first component in one embodiment may be referred to as the second component in another embodiment. Each embodiment described and illustrated herein also includes its complementary embodiment. Furthermore, in this specification, "and / or" is used to mean including at least one of the components listed before and after it.

[0058] In the specification, singular expressions include plural expressions unless the context clearly indicates otherwise. Furthermore, terms such as "include" or "have" are intended to specify the existence of the features, numbers, steps, components, or combinations thereof described in the specification, and should not be understood as excluding the existence or addition of one or more other features, numbers, steps, components, or combinations thereof. Additionally, in this specification, "connection" is used to include both indirectly connecting multiple components and directly connecting them.

[0059] In addition, in describing the present invention below, if it is determined that a detailed description of related known functions or configurations could unnecessarily obscure the essence of the invention, such detailed description will be omitted.

[0060]

[0061] FIG. 1 is a flowchart for explaining a method for manufacturing an IGZO material film according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the process sequence of an IGZO material film according to an embodiment of the present invention more specifically, and FIG. 3 and FIG. 4 are diagrams for explaining an IGZO material film according to an embodiment of the present invention.

[0062] Referring to FIGS. 1 to 4, a substrate (100) is prepared (S100). According to one embodiment, the substrate (100) may be a silicon semiconductor substrate. Alternatively, according to another embodiment, the substrate (100) may be any one of a compound semiconductor substrate, a glass substrate, or a plastic substrate. The type of the substrate (100) is not limited.

[0063] A first unit process (1) for reacting an indium (In) precursor and a first reactant on the substrate (100). stA first material layer (210) containing indium oxide (e.g., In2O3) can be formed by performing a unit process (S200).

[0064] According to one embodiment, the first material layer (210) may be formed by an Atomic Layer Deposition (ALD) process. More specifically, the step of forming the first material layer (210) comprises, as illustrated in FIG. 2, a step of providing an indium precursor (In precursor) on the substrate (100) (S210), a purging step (S220), and a first reactant (1 st It may include a step of providing a reactant (S230) and a purging step (S240). The indium precursor providing step (S210), the purging step (S220), the first reactant providing step (S230), and the purging step (S240) may be defined as the first unit process.

[0065] For example, the above indium precursor may include DADI ((3-Dimethylaminopropyl)dimethylindium). For example, the above indium precursors are TMI(Trimethyl indium), TEI(Triethyl indium), InCA-1(Bis(trimethysilyl)amidodiethyl indium), CpIn(Cyclopentadienylindium), In(tmhd)3((Tris(2,2,6,6-tetramethyl-3,5-heptandionato) indium(III)), In(acac)3((Indium(III) acetylacetonate), DATI((dimethylbutylamino)trimethylindium), Me2In(EDPA)(dimethyl(Nethoxy-2,2-dimethylpropanamido)indium), InEtCp(ethylcyclopentadienyl indium), TMION(Trimethyl[N-(2-methoxyethyl)-2-methylpropan-2-amine]indium), DMION(Dimethyl[N-(tert-butyl)-2-methoxy-2-methylpropan-1-amine]indium), It may include any one of DMITN (Dimethyl[N1-(tert-butyl)-N2,N2-dimethylethane-1,2-diamine]indium), [In[(i Pr)2CNEt2]3] (tris-(N,N′-diisopropyl-2-diethylamido-guanidinato)- indium(III)), [In[(i Pr)2CNMe2]3] (tris-(N,N′-diisopropyl-2-dimethylamidoguanidinato)-indium(III)), In(dmamp)3 (tris(1-dimethylamino-2-methyl-2-propoxy)indium), and tris((N,N'-diisopropylacetamidinato) indium(III)).For example, the first reactant may include oxygen plasma (O2 plasma). As another example, the first reactant may include ozone (O3).

[0066] According to one embodiment, the first material layer (210) may be formed with a thickness greater than 0.5 nm and less than 3 nm. Accordingly, since the first material layer (210) may have an amorphous structure, the formation of the superlattice structure of the IGZO material film described later can be achieved more easily. In contrast, if the first material layer (210) is formed with a thickness of 0.5 nm or less, a problem may arise in which the formation of the IGZO material film described later is not achieved due to the excessively thin thickness, and if the first material layer is formed with a thickness of 3 nm or more, a problem may arise in which the first material layer (210) crystallizes and the formation of the superlattice structure of the IGZO material film described later is not achieved.

[0067] A second unit process (2) for reacting a gallium (Ga) precursor and a second reactant on the first material layer (210) above. nd Performing a unit process) to produce gallium oxide (e.g., GaO x A second material layer (220) including , x>0) can be formed (S300).

[0068] According to one embodiment, the second material layer (220) may be formed by an Atomic Layer Deposition (ALD) process. More specifically, the step of forming the second material layer (220) comprises, as illustrated in FIG. 2, a step of providing a gallium precursor (Ga precursor) on the first material layer (210) (S310), a purging step (S320), and a second reactant (2 ndIt may include a step of providing a reactant (S330) and a purging step (S340). The gallium precursor providing step (S310), the purging step (S320), the second reactant providing step (S330), and the purging step (S340) may be defined as the second unit process.

[0069] For example, the gallium precursor may include TMGa (trimethylgallium). For another example, the gallium precursor is TEGa(Triethyl gallium), Ga(acac)3(Gallium acetylacetonate), [(CH3)2GaNH2]3(dimethylgallium amide), Ga2(NMe2)6(hexakis(dimethylamido)digallium), Me2GaOiPr(dimethylgallium isopropoxide), Ga(OiPr)3(gallium) tri-isopropoxide), [Ga(TMHD)3]([tris (2,2,6,6-tetramethyl-3,5-heptanedionato) gallium(III)]), GaCp (pentamethylcyclopentadienyl gallium), [Ga(thd)3](gallium 2,2,6,6-tetramethyl-3,5-heptanedionate), TMGON (Trimethyl[N-(2-methoxyethyl)-2-methylpropan-2-amine]gallium), It may include either DMGON (Dimethyl[N-(tert-butyl)-2-methoxy-2-methylpropan-1-amine]gallium) and DMGTN (Dimethyl[N1-(tert-butyl)-N2,N2-dimethylethane-1,2-diamine]gallium). For example, the second reactant may include oxygen plasma (O2plasma). As another example, the second reactant may include ozone (O3).

[0070] A third unit process (3) for reacting a zinc (Zn) precursor and a third reactant on the second material layer (220) above. rd Performing a unit process) to produce zinc oxide (e.g., ZnO y A third material layer (230) including , y>0) can be formed (S400).

[0071] According to one embodiment, the third material layer (230) may be formed by an Atomic Layer Deposition (ALD) process. More specifically, the step of forming the third material layer (230) comprises, as illustrated in FIG. 2, a step of providing a zinc precursor (Zn precursor) on the second material layer (220) (S410), a purging step (S420), and a third reactant (3) on the second material layer (220) on which the zinc precursor is provided. rd It may include a step of providing a reactant (S430) and a purging step (S440). The zinc precursor providing step (S410), the purging step (S420), the third reactant providing step (S430), and the purging step (S440) may be defined as the third unit process.

[0072] For example, the zinc precursor may include DEZ (diethylzinc). As another example, the zinc precursor may include any one of DMZ (dimethylzinc), ZnCl2 (zinc chloride), Zn(CH3COO)2 (zinc acetate), Zn(eeki)2 (bis[4-((2-ethoxyethyl)imino)-pent-2-en-2-olate]zinc), and BDMPZ (bis-3-(N,N-dimethylamino)propyl zinc). For example, the third reactant may include oxygen plasma (O2 plasma). As another example, the third reactant may include ozone (O3).

[0073] As the first to third material layers (210, 220, 230) are formed, an IGZO material film (200) in which the first to third material layers (210, 220, 230) are stacked can be formed. According to one embodiment, the first unit process - second unit process - third unit process can be defined as a total process. The total process can be repeated multiple times, and the thickness of the IGZO material film (200) can be controlled according to the number of times the total process is repeated.

[0074] According to one embodiment, the number of repetitions of the first unit process: the second unit process: the third unit process is controlled to be 12:4:4, and after the first unit process is repeated 12 times, the second unit process and the third unit process may be repeated alternately once each, four times. That is, as shown in FIG. 4, after the first material layer (210) is formed, the second material layer (220) and the third material layer (230) may be formed alternately four times on the first material layer (210).

[0075] As described above, as the process sequence for forming the IGZO material film (200) is specifically controlled (the number of repetitions of the first unit process: second unit process: third unit process is 12:4:4 + after the first unit process is repeated 12 times, the second unit process and the third unit process are alternately repeated 4 times each), the superlattice structure of the IGZO material film (200) can be easily formed by the heat treatment described later. In contrast, if the number of repetitions of the first unit process: second unit process: third unit process is controlled as 12:1:1, 12:2:2, 12:3:3, or 12:5:5, a problem may arise in which the superlattice structure is not formed.

[0076] The IGZO material film (200) having the first to third material layers (210, 220, 230) stacked thereon can be heat-treated to form the IGZO material film (200) into a superlattice structure aligned in the C-axis direction (S500). More specifically, when the IGZO material film (200) is heat-treated, the first material layer (210) crystallizes into a bixbyite structure, and the crystallized first material layer (210) is utilized as an embedded seed to form the superlattice structure of the IGZO material film (200).

[0077] According to one embodiment, the IGZO material film (200) can be heat-treated at a temperature of 800°C. That is, the IGZO material film (200), formed by controlling the process sequence as described above, can easily form a superlattice structure even at a low temperature heat treatment of 800°C. In addition, since the IGZO material film (200), formed by controlling the process sequence as described above, does not require a separate seed layer for forming a superlattice structure, it can be formed on various substrates. Accordingly, the method for manufacturing the IGZO material film (200) according to the above embodiment can be easily applied to 3D NAND, GAA, CAA structures, etc.

[0078]

[0079] The IGZO material film and the method for manufacturing the same according to the embodiments of the present invention have been described above. Specific experimental examples are described below.

[0080] Preparation of IGZO material films according to experimental examples

[0081] As described with reference to FIGS. 1 to 4, an IGZO material film was prepared using the ALD method, wherein the first unit process: second unit process: third unit process were performed in a ratio of 12:1:1 to prepare the IGZO material film (BL1) according to Experimental Example 1. More specifically, DADI was used as the In precursor, TMGa was used as the Ga precursor, DEZ was used as the Zn precursor, and O2 plasma was used as the first to third reactants.

[0082] In addition, as described with reference to FIGS. 1 to 4, an IGZO material film was prepared using the ALD method, wherein the first unit process: second unit process: third unit process were performed in a sequence of 12:2:2 to prepare an IGZO material film (BL2) according to Experimental Example 2.

[0083] In addition, as described with reference to FIGS. 1 to 4, an IGZO material film was prepared using the ALD method, and the first unit process: second unit process: third unit process was performed in a sequence of 12:3:3 times to prepare an IGZO material film (BL3) according to Experimental Example 3.

[0084] In addition, as described with reference to FIGS. 1 to 4, an IGZO material film was prepared using the ALD method, wherein the first unit process: second unit process: third unit process were performed in a sequence of 12:4:4 to prepare an IGZO material film (BL4) according to Experimental Example 1.

[0085] Classification 1st Unit Process: 2nd Unit Process: 3rd Unit Process Execution Count BL112:1:1 BL212:2:2 BL312:3:3 BL412:4:4

[0086] Experimental Example 1: Confirmation of Basic Characteristics of BL1 to BL4

[0087] FIG. 5 is a diagram illustrating the composition ratio of IGZO material films according to Experimental Examples 1 to 4 of the present invention, and FIG. 6 is a diagram illustrating the film growth rate, refractive index, and uniformity of IGZO material films according to Experimental Examples 1 to 4 of the present invention.

[0088] Referring to Figure 5, it can be seen that the IGZO material film (BL1) according to Experimental Example 1 has a high In ratio (68 at%) and low Ga (10.4 at%) and Zn ratios (21.6 at%). In contrast, the IGZO material film (BL4) according to Experimental Example 4 shows a decrease in the In ratio (38.0 at%) and an increase in Ga (25.2 at%) and Zn (36.8 at%). That is, it can be seen that as the number of Ga-Zn alternating processes increases, the In ratio decreases and the Ga / Zn ratio increases.

[0089] Referring to Figure 6, it can be seen that the growth rate per cycle increases from Experimental Example 1 to Experimental Example 4 (BL1->BL4), while the refractive index and uniformity decrease from Experimental Example 1 to Experimental Example 4 (BL1->BL4). In other words, it can be seen that as the number of Ga-Zn alternating processes increases, the growth rate increases, while the refractive index and uniformity decrease.

[0090] Figure 7 is a TEM image of an IGZO material film according to Experimental Example 1 of the present invention, and Figure 8 is a TEM image of an IGZO material film according to Experimental Example 4 of the present invention.

[0091] As can be seen in Figures 7 and 8, the IGZO material film (BL1) according to Experimental Example 1 has an interlayer spacing (d) of 1.13 nm, and the IGZO material film (BL4) according to Experimental Example 4 has an interlayer spacing (d) of 1.6 nm. In other words, it can be seen that as the number of Ga-Zn alternating process steps increases, a more uniform film is formed.

[0092]

[0093] Experimental Example 2: Confirmation of structural changes in BL1 to BL4 due to heat treatment

[0094] FIG. 9 is a diagram illustrating the XRD analysis results for the state of the IGZO material film according to Experimental Examples 1 to 4 of the present invention before heat treatment, FIG. 10 is a diagram illustrating the XRD analysis results for the state of the IGZO material film according to Experimental Examples 1 to 4 of the present invention after heat treatment at a temperature of 400°C, FIG. 11 is a diagram illustrating the XRD analysis results for the state of the IGZO material film according to Experimental Examples 1 to 4 of the present invention after heat treatment at a temperature of 600°C, and FIG. 12 is a diagram illustrating the XRD analysis results for the state of the IGZO material film according to Experimental Examples 1 to 4 of the present invention after heat treatment at a temperature of 800°C.

[0095] Referring to Fig. 9, it can be seen that in the state before heat treatment, only small peaks of 10° or less are observed in all IGZO material films (BL1~BL4) according to Experimental Examples 1 to 4. That is, it can be seen that the IGZO material film exists in a nanolaminate structure and has almost no crystallinity.

[0096] Referring to Fig. 10, it can be seen that even when heat-treated at a temperature of 400°, only small peaks of 10° or less are observed in all IGZO material films (BL1~BL4) according to Experimental Examples 1 to 4. That is, it can be seen that the IGZO material film exists in a nanolaminate structure and has almost no crystallinity.

[0097] Referring to Fig. 11, it can be seen that when heat-treated at a temperature of 600°C, almost no peaks appear in all IGZO material films (BL1~BL4) according to Experimental Examples 1 to 4. In other words, it can be seen that the IGZO material film has changed into an amorphous structure.

[0098] Referring to Fig. 12, it can be seen that when heat-treated at a temperature of 800°C, distinct peaks appear in various ranges for all IGZO material films (BL1~BL4) according to Experimental Examples 1 to 4. In other words, it can be seen that the IGZO material film has crystallized.

[0099] FIG. 13 is a diagram illustrating the GIWAXS analysis results for an IGZO material film heat-treated at a temperature of 800°C according to Experimental Example 1 of the present invention, FIG. 14 is a diagram illustrating the GIWAXS analysis results for an IGZO material film heat-treated at a temperature of 800°C according to Experimental Example 2 of the present invention, FIG. 15 is a diagram illustrating the GIWAXS analysis results for an IGZO material film heat-treated at a temperature of 800°C according to Experimental Example 3 of the present invention, and FIG. 16 is a diagram illustrating the GIWAXS analysis results for an IGZO material film heat-treated at a temperature of 800°C according to Experimental Example 4 of the present invention.

[0100] As can be seen in FIGS. 13 to 16, the (0003), (0006), and (0009) peaks do not appear in the case of the IGZO material film (BL1) according to Experimental Example 1, whereas the (0003), (0006), and (0009) peaks appear in the case of the IGZO material films (BL2 to BL4) according to Experimental Examples 2 to 4. In addition, it can be seen that in the case of the IGZO material films (BL1~BL3) according to Experimental Examples 1 to 3, the (222) peak, (121) peak, (112) peak, (222) peak, and (040) peak appear, but in the case of the IGZO material films (BL1~BL4) according to Experimental Example 4, the (222) peak, (121) peak, (112) peak, (222) peak, and (040) peak do not appear.

[0101] Consequently, in the case of the IGZO material film (BL4) according to Experimental Example 4, which was manufactured with the first unit process: second unit process: third unit process in a cycle of 12:4:4, the GIWAXS results show that peaks (0003), (0006), and (0009) are observed, while peaks (222), (121), (112), (222), and (040) are not observed. In particular, in the case of the IGZO material film (BL4) according to Experimental Example 4, only peaks (0003), (0006), and (0009) are observed, indicating that a superlattice structure aligned in the C-axis direction has been formed.

[0102] FIG. 17 is a diagram illustrating the TEM analysis results for an IGZO material film according to Experimental Example 1 of the present invention that has been heat-treated at a temperature of 800°C, FIG. 18 is a diagram illustrating the TEM analysis results for an IGZO material film according to Experimental Example 2 of the present invention that has been heat-treated at a temperature of 800°C, FIG. 19 is a diagram illustrating the TEM analysis results for an IGZO material film according to Experimental Example 3 of the present invention that has been heat-treated at a temperature of 800°C, FIG. 20 is a diagram illustrating the TEM analysis results for an IGZO material film according to Experimental Example 4 of the present invention that has been heat-treated at a temperature of 800°C, and FIG. 21 is a diagram illustrating the phase transition process of an IGZO material film according to Experimental Examples 1 to 4 of the present invention.

[0103] Referring to FIG. 17, it can be seen that the IGZO material film (BL1) according to Experimental Example 1 has a Bixbyite crystal structure of In2O3, and that crystal planes (111) and (400) are observed. Additionally, it can be seen that the d-spacing between (111) crystal planes is 2.95 Å and the d-spacing between (400) crystal planes is 2.46 Å. That is, it shows a uniform single-phase crystal structure overall, and it can be seen that there are almost no other phases.

[0104] Referring to Fig. 18, it can be confirmed that the IGZO material film (BL2) according to Experimental Example 2 exhibits a new crystal structure while partially maintaining the existing In2O3Bixbyite structure ((0003) crystal planes appear). Additionally, it can be confirmed that the (111) inter-plane spacing (d-spacing) is 2.98 Å and the (0003) inter-plane spacing is 8.98 Å. In other words, grain boundaries are formed, indicating a mixed-phase state where In2O3 and a new phase coexist.

[0105] Referring to Fig. 19, it can be seen that the IGZO material film (BL3) according to Experimental Example 3 shows that the existing In2O3Bixbyite structure has almost disappeared and has transitioned into a new crystalline phase. (0003) It can be seen that an octahedral structure has been formed, as the crystal planes appear more distinctly. In addition, it can be seen that the (400) inter-plane spacing (d-spacing) is 2.46 Å and the (0003) inter-plane spacing is 9.22 Å. That is, although it is still a mixed-phase, it can be seen that the In2O3 is gradually decreasing and converting into an IGZO structure.

[0106] Referring to FIG. 20, it can be seen that in the IGZO material film (BL4) according to Experimental Example 4, the existing mixed phase disappears and a completely new superlattice structure is formed. In addition, it can be seen that the (0003) inter-plane spacing (d-spacing) is 8.89 Å and 9.23 Å.

[0107] Referring to FIG. 21 (a) to (d), the phase transition process of IGZO material films (BL1 to BL4) according to Experimental Examples 1 to 4, which were heat-treated at a temperature of 800°C, is shown. As can be seen in FIG. 21, the crystal structure changes from BL1 (Bixbyite-In2O3) -> BL2 (mixed phase) -> BL3 (octahedra) -> BL4 (superlattice-IGZO). More specifically, starting from BL2, the (0003) plane appears and the transition to the IGZO structure begins, and in BL4, a complete superlattice structure is formed and the arrangement of Ga / Zn becomes stable.

[0108] As a result, it can be seen that in order to manufacture IGZO with a superlattice structure, the number of repetitions of the first unit process: second unit process: third unit process is controlled to 12:4:4, and after the first unit process is repeated 12 times, the second unit process and the third unit process must each be repeated alternately once, four times each. In addition, the superlattice structured IGZO material film manufactured through the process sequence control described above shows that the (0003), (0006), and (0009) peaks are observed as a result of GIWAXS analysis, while the (222), (121), (112), (222) peaks and (040) peaks are not observed, and as a result of HRTEM analysis, the (0003) interplane distance (d-spacing) is confirmed to be 0.88 nm to 0.93 nm, and the (111) and (400) planes are not confirmed.

[0109] FIG. 22 is a diagram illustrating the change in state of an IGZO material film according to the heat treatment time in Experimental Example 4 of the present invention.

[0110] Referring to FIG. 22 (a) to (f), the IGZO material film (BL4) according to Experimental Example 4 was heat-treated at a temperature of 800°C for 60 minutes, and the change in state according to the heat treatment time was confirmed through XRD (X-ray Diffraction) analysis.

[0111] As can be seen in FIG. 22 (a) to (f), the state before heat treatment is amorphous, but as heat treatment is performed, the state changes from Bixbyite In2O3 to superlattice IGZO. That is, when the IGZO material film is heat-treated, the first material layer (In2O3) crystallizes into a Bixbyite structure, and the crystallized first material layer (In2O3) is utilized as an embedded seed, so that the superlattice structure of the IGZO material film (200) is formed.

[0112]

[0113] Experimental Example 3: Confirmation of Process Sequence Dependence and Verification of In2O3 Thickness for Superlattice Structure Expression

[0114] As described with reference to FIGS. 1 to 4, an IGZO material film was prepared using the ALD method, wherein the first unit process: second unit process: third unit process were performed in a ratio of 3:1:1 to prepare an IGZO material film (BL5) according to Experimental Example 5.

[0115] In addition, as described with reference to FIGS. 1 to 4, an IGZO material film was prepared using the ALD method, and the first unit process: second unit process: third unit process was performed in a ratio of 6:2:2 to prepare an IGZO material film (BL6) according to Experimental Example 6.

[0116] In addition, as described with reference to FIGS. 1 to 4, an IGZO material film was prepared using the ALD method, and the first unit process: second unit process: third unit process was performed in a ratio of 9:3:3 to prepare an IGZO material film (BL7) according to Experimental Example 7.

[0117] In addition, a 2 nm thick InO layer on a substrate using the ALD method with DBADMIn (In precursor) and ozone (reactant) xA material film (x>0) was formed, and this was applied to the InO according to Experimental Example 1. x It was defined as a material film (Ex 1).

[0118] In addition, a 3 nm thick InO layer on a substrate using the ALD method with DBADMIn (In precursor) and ozone (reactant) x A material film (x>0) was formed, and this was applied to the InO according to Experimental Example 2. x It was defined as a material film (Ex 2).

[0119] In addition, a 5 nm thick InO layer on a substrate using the ALD method with DBADMIn (In precursor) and ozone (reactant) x A material film (x>0) was formed, and this was applied to the InO according to Experimental Example 3. x It was defined as a material film (Ex 3).

[0120] Classification 1st Unit Process: 2nd Unit Process: 3rd Unit Process Execution Count BL412:4:4 BL53:1:1 BL66:2:2 BL79:3:3

[0121] Classification Material Film Type Material Film Thickness Ex 1 In O x (x>0)2 nmEx 2InO x (x>0)3 nmEx 3InO x (x>0)5 nm

[0122] FIG. 23 is a diagram illustrating the composition ratio of IGZO material films according to Experimental Examples 4 to 7 of the present invention, and FIG. 24 is a diagram illustrating the crystal state of IGZO material films according to Experimental Examples 4 to 7 of the present invention.

[0123] Referring to FIGS. 23 (a) and (b), the composition ratios of IGZO material films (BL4~BL7) according to Experimental Examples 4 to 7 are shown. More specifically, FIGS. 23 (a) shows the composition ratio before heat treatment, and FIGS. 23 (b) shows the composition ratio after heat treatment at a temperature of 800°C. As can be seen in FIGS. 23 (a) and (b), it can be confirmed that the IGZO material films according to Experimental Examples 4 to 7 have substantially the same composition ratio.

[0124] Referring to FIGS. 24 (a) and (b), XRD analysis results for IGZO material films (BL4~BL7) according to Experimental Examples 4 to 7 are shown. More specifically, FIGS. 24 (a) shows the composition ratio before heat treatment, and FIGS. 24 (b) shows the composition ratio after heat treatment at a temperature of 800°C.

[0125] As can be seen in Fig. 24 (a), all materials are in an amorphous state before heat treatment, but as can be seen in Fig. 24 (b), the IGZO material films (BL4, BL7) according to Experimental Example 4 and Experimental Example 7 are transformed into a superlattice structure by heat treatment. However, in the case of the IGZO material films (BL5, BL6) according to Experimental Example 5 and Experimental Example 6, it can be seen that a superlattice structure is not formed despite heat treatment. In other words, it can be seen that the formation of a superlattice structure of the IGZO material film is more influenced by the control of the process sequence than by the control of the composition. In addition, in order for the formation of a superlattice structure to occur, the first unit process: second unit process: third unit process must be performed in a ratio exceeding at least 6:2:2, and in this case, since the thickness of the first material layer (In2O3) is 0.5 nm, it can be seen that the thickness of the first material layer (In2O3) must be formed to exceed at least 0.5 nm.

[0126] FIG. 25 is InO according to Experimental Examples 1 to 3 of the present invention x This is a diagram illustrating the XRD analysis results of a material film.

[0127] Referring to FIG. 25, the XRD analysis results of the InOx material films (Ex 1 to Ex 3) according to Experimental Examples 1 to 3 are shown. More specifically, FIG. 25 (a) to (c) shows the analysis results of the InOx material films according to Experimental Examples 1 to 3 before heat treatment, and FIG. 25 (d) to (f) shows the state of the InOx material films according to Experimental Examples 1 to 3 after heat treatment at a temperature of 400°C.

[0128] As can be seen in FIGS. 25 (a) to (f), the InO according to Experimental Example 1 above x While the material film has an amorphous structure regardless of heat treatment, the InO according to Experimental Examples 2 and 3 above x It can be confirmed that crystallization of the material film occurred regardless of heat treatment.

[0129] FIG. 26 shows InO according to Experimental Examples 1 and 2 of the present invention. x This is a diagram illustrating the HRTEM analysis results of the material film.

[0130] Referring to FIG. 26, the InO according to Experimental Example 1 and Experimental Example 2 above x HRTEM analysis results of the material film are shown. More specifically, FIG. 26(a) shows the InO according to Experimental Example 1 formed at 250°C. x The analysis results of the material film are shown, and FIG. 26(b) is the InO according to Experimental Example 2 formed at 200°C. x The analysis results of the material film are shown, and FIG. 26 (c) is the InO according to Experimental Example 2 formed at 250°C. xThe analysis results of the material film are shown, and FIG. 26 (d) is the InO according to Experimental Example 2 formed at 300°C. x The analysis results of the material film are shown. As can be seen in FIGS. 26 (a) to (d), the InO according to Experimental Example 1 above x While the material film has an amorphous structure, the InO according to Experimental Example 2 above x It can be confirmed that crystallization has occurred in the material film.

[0131] Consequently, it can be seen that in order to form an IGZO material film with a superlattice structure based on an In2O3 material film with an amorphous structure, the thickness of the In2O3 material film must be controlled to be greater than 0.5 nm and less than 3 nm.

[0132]

[0133] Experimental Example 4: Transistor with Superlattice IGZO Material Film

[0134] FIG. 27 is a diagram illustrating a transistor according to Experimental Example 4 of the present invention.

[0135] Referring to FIG. 27, an IGZO material film (BL4) according to Experimental Example 4 was applied as the active layer, and a transistor having a vertical channel structure was fabricated as shown in FIG. 27. In addition, a material having an amorphous structure (SiO2) was used as a spacer.

[0136] Figure 28 is an image of a transistor according to Experimental Example 4 of the present invention.

[0137] Referring to FIG. 28, the TEM image and element mapping results of the transistor according to Experimental Example 4 are shown. As can be seen in FIG. 28, the IGZO material film (BL4) according to Experimental Example 4 can be formed on various substrates without a seed layer.

[0138] FIG. 29 is a diagram illustrating the current-voltage characteristics of a transistor according to Experimental Example 4 of the present invention, FIG. 30 is a diagram illustrating the change in threshold voltage according to heat treatment of a transistor according to Experimental Example 4 of the present invention, FIG. 31 is a diagram illustrating the stress test results of a transistor according to Experimental Example 4 of the present invention, and FIG. 32 is a diagram illustrating the long-term operational stability of a transistor according to Experimental Example 4 of the present invention.

[0139] Referring to FIG. 29, the transfer curve (left) and output curve (right) of the transistor according to Experimental Example 4 above are shown. As can be seen in FIG. 29, V GS As I increase D It can be seen that normal transistor operation was achieved as it increased rapidly. In addition, V DS As I increase D It can be seen that normal transistor operation was achieved as it increased linearly.

[0140] Referring to Fig. 30, the voltage change of the transistor according to Experimental Example 4, which was heat-treated at 600°C for 1 hour, is shown. As can be seen in Fig. 31, the change in threshold voltage (ΔV) even after heat treatment th It can be confirmed that there is no ). In other words, it can be seen that the transistor according to Experiment Example 4 above has high stability even in a high-temperature environment.

[0141] Referring to Fig. 31, the PBTS test results (left) and NBTS test results (right) of the transistor according to Experimental Example 4 are shown. As can be seen in Fig. 31, when a positive bias voltage is applied, the threshold voltage decreases slightly but does not show a significant change, and when a negative bias voltage is applied, the threshold voltage increases slightly but does not show a significant change. In other words, it can be seen that the transistor according to Experimental Example 4 maintains its characteristics stably during the stress test.

[0142] Referring to FIG. 32, for the transistor according to Experimental Example 4 above, V GS =5V, V DS The change in drain current (ID) was measured for 10,000 seconds under the condition of =5.1V. As can be seen in Fig. 32, it was confirmed that the current maintained 88.66% of the initial current even after 10,000 seconds of measurement. In other words, it can be seen that the transistor according to Experimental Example 4 above can maintain stable current characteristics even during long-term operation.

[0143]

[0144] Although the present invention has been described in detail using preferred embodiments, the scope of the invention is not limited to specific embodiments and should be interpreted by the appended claims. Furthermore, those skilled in the art will understand that many modifications and variations are possible without departing from the scope of the invention.

[0145] The present invention can be used in the semiconductor industry.

Claims

1. Step of preparing the substrate; A step of forming a first material layer containing indium oxide by performing a first unit process of reacting an indium (In) precursor and a first reactant on the substrate; A step of forming a second material layer containing gallium oxide by performing a second unit process of reacting a gallium (Ga) precursor and a second reactant on the first material layer; A step of forming a third material layer containing zinc oxide by performing a third unit process of reacting a zinc (Zn) precursor and a third reactant on the second material layer; and A method for manufacturing an IGZO material film comprising the step of heat-treating the IGZO material film, wherein the first to third material layers are stacked, to form the IGZO material film into a superlattice structure.

2. In Paragraph 1, A method for manufacturing an IGZO material film, comprising forming the above IGZO material film into a superlattice structure at a heat treatment temperature of 800°C.

3. In Paragraph 1, A method for manufacturing an IGZO material film comprising controlling the number of repetitions of the first unit process, the second unit process, and the third unit process to 12:4:

4.

4. In Paragraph 3, A method for manufacturing an IGZO material film comprising, after the first unit process is repeated 12 times, the second unit process and the third unit process are alternately repeated 4 times each.

5. In Paragraph 1, A method for manufacturing an IGZO material film, comprising forming the first material layer with a thickness of more than 0.5 nm and less than 3 nm.

6. In Paragraph 1, A method for manufacturing an IGZO material film comprising the first material layer having an amorphous structure.

7. In Paragraph 1, A method for manufacturing an IGZO material film, comprising forming the IGZO material film into a superlattice structure after the first material layer is crystallized when the IGZO material film is heat-treated.

8. In Paragraph 7, A method for manufacturing an IGZO material film, wherein when the above IGZO material film is heat-treated, the first material layer crystallizes into a bixbyite structure.

9. Including indium (In), gallium (Ga), zinc (Zn), and oxygen (O), IGZO material film having a superlattice structure aligned in the C-axis direction.

10. In Paragraph 9, IGZO material film including peaks (0003), (0006), and (0009) observed in GIWAXS analysis results.

11. In Paragraph 10, IGZO material film including (222) peak, (121) peak, (112) peak, (222) peak, and (040) peak not observed as a result of GIWAXS analysis.

12. In Paragraph 9, An IGZO material film comprising (0003) an interplane spacing (d-spacing) of 0.88 nm to 0.93 nm as confirmed by HRTEM analysis results.

13. In Paragraph 9, IGZO material film containing (111) crystal planes and (400) crystal planes that were not identified as a result of HRTEM analysis.

Images