Method for selective growth of TMD and substrate having selectively grown tmd

Abstract

A method for selective growth of a TMD and a substrate having selectively grown TMD are provided. A method for selective growth of a TMD according to one embodiment comprises: preparing a template having a plurality of selective growth regions; and selectively growing a TMD film in the selective growth regions, wherein the size (d) of at least one of the selective growth regions is 2 um or more.

Description

Method for selective growth of TMDs and substrate having selectively grown TMDs

[0001] The present invention relates to a method for growing transition metal dichalcogenide (TMD) and a substrate having grown TMD, and more particularly, to a method for selectively growing TMD and a substrate having selectively grown TMD.

[0002] In the semiconductor industry, semiconductor miniaturization is progressing to achieve high-performance, highly integrated devices. Existing semiconductor devices using silicon as the channel material suffer from the single-channel effect at fine linewidths. To address this issue, research is underway to structurally improve the devices and explore alternative materials for silicon.

[0003] Two-dimensional materials are being studied as alternatives to silicon. Due to their unique optical and electrical properties, two-dimensional materials are being explored for diverse applications, and various growth and deposition methods are being developed. TMDs, as two-dimensional materials, maintain stability even at nanoscale thicknesses. However, for the mass production and industrial application of two-dimensional materials such as TMDs, compatibility with existing semiconductor device production processes is required, and improving the crystallinity of TMDs remains a challenge.

[0004] However, conventional techniques for forming TMDs have problems such as difficulty in large-area growth, high process temperatures, and can cause misalignment due to physical surface treatment and physical transport. Furthermore, expensive substrates such as sapphire must be used, and it is difficult to stack on an amorphous layer. In particular, among various growth / deposition methods, techniques such as chemical vapor deposition (CVD), metalorganic chemical vapor deposition (MOCVD), and atomic layer deposition (ALD) have been proposed for industrial applications due to their high compatibility with the mass production processes of existing semiconductor devices. However, improvements in nucleation control and growth control techniques are required to form large-area, highly uniform thin films.

[0005] Recently, nucleation / growth control technologies utilizing selective thin film growth based on the substrate material and its shape have been reported. In addition to nucleation and growth control, selective growth offers the advantages of shortening the process, eliminating PR residue (since it does not use photoresist), and eliminating misalignment.

[0006] However, prior arts suggesting selective growth techniques place significant restrictions on the types of materials and / or pattern sizes that can be selectively grown. For example, prior art 1 (U.S. Patent Application Publication No. US2024 / 0071759 A1 (February 29, 2024)) uses a mask to form trenches surrounded on all sides, and the maximum horizontal dimension of each trench is limited to 2 μm. Prior art 2 (U.S. Patent Application Publication No. US2024 / 0018686 A1 (June 18, 2024)) discloses a template for growing crystals of a two-dimensional material, the template having a structure in which at least two walls arranged on a substrate meet at a corner, and the length of each wall is in the range of 5 to 1000 nm.

[0007] These shape and size limitations of the selective growth region limit semiconductor circuit design and integration. In particular, applications such as GPU cores require the growth of relatively large-area TMDs. Furthermore, prior art document 1 employs a powder-based CVD technique, making it difficult to apply to existing industrial lines. Prior art document 2 exhibits a selective growth yield of less than 90%, which can lead to undesirable growth.

[0008] The problem to be solved by the present invention is to provide a method for selectively growing TMDs that can increase the size of a selective growth region.

[0009] Another problem that the present invention seeks to solve is to provide a substrate having TMD selective growth regions of relatively large area by using the above TMD selective growth method.

[0010] A method for selective growth of a TMD according to one embodiment of the present invention comprises preparing a template having a plurality of selective growth regions and selectively growing a TMD film on the selective growth regions, wherein a size (d) of at least one of the selective growth regions is 2 μm or more.

[0011] In one embodiment, the template may include: a base substrate; a first material layer disposed on the substrate; and a second material layer disposed to expose at least a portion of the first material layer, wherein the selected growth regions may be regions of the first material layer or regions of the second material layer.

[0012] The first material layer and the second material layer may be formed as an oxide film, a nitride film, or an oxynitride film, respectively, and at least one of the elements, composition ratio, or deposition method of the first material layer may be different from the elements, composition ratio, or deposition method of the second material layer, and the first material layer and the second material layer have different selectivities for TMD growth, and the TMD can be selectively grown only on the material layer having high selectivity among the first material layer and the second material layer.

[0013] In one embodiment, one of the first material layer and the second material layer, which provides selective growth regions as a material layer having high selectivity for TMD, may be selected from the group consisting of AlOx, SiNx, SiOx, TiNx, TiOx, AlNx, MoOx, SiOxNy, TiOxNy, or AlOxNy, and the other of the first material layer and the second material layer may be selected from the group consisting of HfOx, ZrOx, TaOx, or LaOx.

[0014] Furthermore, as the material layer having high selectivity of the TMD, one material layer may be AlOx, SiOx, or SiNx, and the other material layer may be HfOx or ZrOx.

[0015] Additionally, the selective growth regions may have a negative structure or a positive structure, or the surfaces of the selective growth regions may be coplanar with the surfaces of the non-growth regions surrounding them.

[0016] In one embodiment, the size (d) of at least one of the selected growth regions may be 4 μm or greater.

[0017] The upper limit of the size of the above-mentioned selective growth regions is not particularly limited, but may be limited to a specific size in consideration of crystal quality such as single crystal growth, polycrystalline growth, double layer or triple layer growth, etc., and may be, for example, about 10 um.

[0018] The above-described selective growth regions are not limited to a specific shape and may have, for example, a circular, elliptical, or polygonal shape.

[0019] The above TMD film can be grown using a metalorganic chemical vapor deposition (MOCVD) technique using a transition metal precursor and a chalcogen precursor.

[0020] The above organometallic chemical vapor deposition method can further utilize a promoter.

[0021] In one embodiment, the promoter may be an organic or inorganic compound comprising an alkali metal.

[0022] In one embodiment, the growth temperature may be greater than or equal to 300°C and less than or equal to 750°C.

[0023] The above TMD film is a single crystal and can be grown as a single layer, double layer, or triple layer.

[0024] A substrate having selectively grown TMDs according to one embodiment of the present invention comprises: a template having a plurality of selective growth regions; and TMD films disposed within the selective growth regions, wherein a size (d) of at least one of the selective growth regions is 2 μm or greater.

[0025] The template may include a base substrate; a first material layer disposed on the base substrate; and a second material layer patterned to expose at least a portion of the first material layer, wherein the selected growth regions may be regions of the first material layer or regions of the second material layer.

[0026] In one embodiment, the first material layer and the second material layer may be an oxide film, a nitride film, or an oxynitride film, respectively, and the elements or composition ratio of the first material layer may be different from the elements or composition ratio of the second material layer, or the first material layer may be formed by a deposition method different from the deposition method of the second material layer, and the TMD may be selectively disposed only on regions of the first material layer or regions of the second material layer.

[0027] Meanwhile, one of the first material layer and the second material layer providing selective growth regions may be selected from the group consisting of AlOx, SiNx, SiOx, TiNx, TiOx, AlNx, MoOx, SiOxNy, TiOxNy, or AlOxNy, and the other of the first material layer and the second material layer may be selected from the group consisting of HfOx, ZrOx, TaOx, or LaOx.

[0028] Furthermore, the one material layer may be AlOx, SiOx, or SiNx, and the other material layer may be HfOx or ZrOx.

[0029] Additionally, the selective growth regions may have a negative structure or a positive structure, or the surfaces of the selective growth regions may be coplanar with the surfaces of the non-growth regions surrounding them.

[0030] In one embodiment, the size (d) of at least one of the selected growth regions may be 4 μm or greater.

[0031] The above TMD films may be single crystals and may be single-layer, double-layer, or triple-layer.

[0032] According to embodiments of the present invention, the size of the selective growth region of TMD can be increased, and thus, TMD can be easily applied to various fields such as optical devices and semiconductor devices.

[0033] Figure 1 is a schematic diagram illustrating a growth device according to one embodiment of the present invention.

[0034] FIG. 2a is a schematic cross-sectional view illustrating a template for growing a TMD according to one embodiment of the present invention.

[0035] FIG. 2b is a schematic cross-sectional view illustrating a template for growing a TMD according to another embodiment of the present invention.

[0036] FIG. 3 is a schematic plan view illustrating various shapes of a selective growth region according to one embodiment of the present invention.

[0037] FIG. 4a is a schematic flowchart illustrating a TMD selective growth method according to one embodiment of the present invention.

[0038] FIG. 4b is a schematic flowchart for explaining a TMD selective growth method according to another embodiment of the present invention.

[0039] Figure 5a is an SEM image showing TMDs grown on a second material, which is a mask material.

[0040] Figure 5b is an SEM image showing TMDs grown within the selected growth region.

[0041] Figure 6 is a Raman spectrum showing the presence or absence of TMD growth on SiO2 and HfO2 of Figure 5b.

[0042] Figure 7a is an SEM image of a sample grown with TMD using SiNx and HfOx as the first and second materials (mask materials).

[0043] Figure 7b is an SEM image of a sample grown with TMD using SiOx and SiNx as the first material and the second material (mask material).

[0044] Figure 8a is an SEM image of a sample grown with TMD using AlOx and HfOx as the first and second materials (mask materials).

[0045] Figure 8b is an SEM image of a sample grown with TMD using SiOx and AlOx as the first material and the second material (mask material).

[0046] Figure 8c is an SEM image of a sample grown with TMD using AlOx and SiNx as the first and second materials (mask materials).

[0047] Figure 9 is an SEM image of a sample grown with TMD using SiOx and HfOx as the first and second materials (mask materials), respectively.

[0048] Figure 10 is an SEM image of a sample grown with TMD using a-SiO2 and a-ZrO2 as the first and second materials (mask materials).

[0049] Figure 11 is a set of SEM images showing the presence or absence of TMD growth depending on the size of the selected growth area under the first experimental condition.

[0050] Figure 12 is a set of SEM images showing the presence or absence of TMD growth depending on the size of the selected growth area under the second experimental condition.

[0051] Figure 13 is an SEM image showing TMDs growing in a triangular-shaped selective growth region with a side size of approximately 2 μm.

[0052] Figures 14a to 14d are SEM images showing TMDs grown within selective growth regions of various shapes.

[0053] Figure 15 is a schematic diagram and SEM images showing the growth process of TMD within a selected growth region according to growth time.

[0054] Figure 16a is an SEM image of a sample grown with TMDs without selective growth according to a conventional technique.

[0055] FIG. 16b is an SEM image of a sample in which TMDs are grown within a selective growth region through selective growth according to one embodiment.

[0056] Figure 17a is a cross-sectional TEM image showing a monolayer TMD.

[0057] Figure 17b is a cross-sectional TEM image showing a multi-layer TMD.

[0058] Figure 18 shows SEM images and Raman spectra showing selective growth depending on the growth temperature.

[0059] Figure 19 shows SEM images and Raman spectra showing TMD growth at growth temperatures above 750°C.

[0060] Figure 20 shows SEM images showing TMD growth at a growth temperature near 480°C.

[0061] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. The embodiments introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art to which the present invention pertains. Therefore, the present invention is not limited to the embodiments described below and may be embodied in other forms. In addition, in the drawings, the width, length, thickness, etc. of components may be expressed in an exaggerated manner for convenience. In addition, when one component is described as being "over" or "on" another component, it includes not only cases where each part is "directly over" or "directly on" the other part, but also cases where another component is interposed between each component and another component. Like reference numbers represent like components throughout the specification.

[0062] (Growth Device and Template)

[0063] FIG. 1 is a schematic diagram illustrating a growth device (100) according to one embodiment of the present invention. The growth device (100) may be a metalorganic chemical vapor deposition (MOCVD) device, but is not particularly limited thereto. Although the drawing illustrates the use of a horizontal flow space, the growth device 100 is not particularly limited thereto. For example, it may be a vertical flow space using a showerhead method. Furthermore, although the drawing illustrates a single-wafer method, the growth device 100 is not particularly limited thereto. For example, multiple substrates may be processed simultaneously in a batch type method. The MOCVD device can provide TMD in large quantities, making it suitable for industrial applications. Hereinafter, the growth device (100) will be described using an MOCVD device as an example.

[0064] Referring to FIG. 1, the growth device (100) may include a chamber (11), a gas inlet (13), and a gas outlet (15).

[0065] The chamber (11) provides a sealed space for TMD growth. The interior of the chamber (11) can be evacuated using a vacuum pump. During the reaction, the interior of the chamber (11) can maintain a constant temperature and pressure. The chamber (11) has a mounting platform for placing a template (20), and the mounting platform includes a heater to heat the template (20).

[0066] A template (20) having a growth region defined within a chamber (11) is placed. The template (20) may include a base substrate (21), a first material layer (23), and a second material layer (25), as illustrated in FIGS. 2A and 2B . The base substrate (21) may replace the first material layer (23), in which case the first material layer (23) may be omitted. The second material layer (25) may be patterned to expose the first material layer (23). The exposed region of the first material layer (23) may be surrounded by the second material layer (25), thereby forming a pocket. The pocket may have various shapes, such as a circle and a polygon, as illustrated in FIG. 3 . For reference, the double-headed arrows in Fig. 3 are used to define the pocket size (d) of the shape. In the case of a circle, the pocket size (d) is defined as the diameter, in the case of an ellipse, the short-axis diameter, in the case of a triangle or a square, the length of the shortest side, and in the case of a polygon larger than a pentagon, the pocket size (d) is defined as the length of the shortest diagonal among the diagonals between the vertices that are located farthest from each other.

[0067] In Fig. 2a, the pocket formed by patterning the second material layer (25) has a negative structure. In this case, TMDs can be selectively grown on the exposed first material layer (23).

[0068] In the embodiment of Fig. 2a, the second material layer (25) is disposed on the first material layer (23). Alternatively, as illustrated in Fig. 2b, the first material layer (23) may be patterned to expose the base substrate (21), and the second material layer (25) may be formed on the exposed base substrate (21). In this case, a selective growth region of the negative structure can be defined by making the thickness of the second material layer (25) greater than that of the first material layer (23).

[0069] Meanwhile, in the embodiments of the present invention, the template (20) is not limited to having a growth region of a negative structure, and may, for example, have a growth region of a positive structure. For example, in the embodiment of FIG. 2B, the growth region of a positive structure can be defined by making the thickness of the first material layer (23) thicker than the second material layer (25). Alternatively, after forming the second material layer (25) on the first material layer (23), the second material layer (25) is patterned to expose the first material layer (23), but the second material layer (25) is surrounded by the exposed first material layer (23), thereby defining the growth region with the second material layer (25) of the positive structure, and growing the TMD on the second material layer (25). The growth region in the positive structure can also have various shapes, such as a circle or a polygon, as illustrated in FIG. 3. In this case, TMD can be selectively grown on the second material layer (25).

[0070] Although some embodiments of forming negative and positive structures are described, the present invention is not limited to these embodiments, and selective growth regions of negative or positive structures can be formed in various ways.

[0071] In other embodiments, unlike the negative or positive structures, the selective growth region can be coplanar with the surrounding non-growth region. For example, in the embodiment of FIG. 2b, the non-growth region and the growth region can be formed to be coplanar by making the first material layer (23) and the second material layer (25) the same thickness.

[0072] Various gas sources (13a, 13b, 13c, 13d) including transition metal precursors are connected to the gas inlet (13). For example, the first gas source (13a) may be a transition metal precursor, the second gas source (13b) may be a chalcogen precursor, the third gas source (13c) may be a carrier gas, and the fourth gas source (13d) may be a promoter and / or an oxidizer. The gas sources are not limited to these, and may further include other gas sources, such as a reducing agent, or the fourth source gas may not be supplied.

[0073] Examples of transition metal precursors include Mo(CO)6, W(CO)6, etc., and examples of chalcogen precursors include (C2H5)2S, (CH3)2Se, etc. Meanwhile, an organic metal promoter or an inorganic metal promoter can be used, and for example, sodium propanoate (SP) is preferred as a promoter because it has a high vapor pressure, a low decomposition temperature, and is harmless with no residual byproducts. Meanwhile, Ar, N2, H2, etc. can be used as a carrier gas, and O2 can be used as an oxidizer, but the present invention is not limited thereto.

[0074] Gases are introduced into the chamber (11) through the gas inlet (13), and after the gases react within the chamber (11), gases containing reaction by-products are discharged through the gas outlet (15).

[0075] The lower the TMD growth temperature, the more advantageous it is for industrial applications, and in embodiments of the present invention, the growth temperature may be, for example, lower than 750°C. The lower limit of the TMD growth temperature may be limited by the supply method of precursors, decomposition temperature, type of promoter, etc., and further may vary depending on the types of the first material layer (23) and the second material layer (25) for selective growth. In embodiments of the present invention, the TMD growth temperature may be, for example, 300°C or higher, and further, 400°C or higher.

[0076] The pressure within the chamber for TMD growth may vary depending on the type of TMD, for example, within the range of 0.1 to 700 torr, further within the range of 1 to 100 torr, and further within the range of 3 to 10 torr.

[0077] (Selection Growth Method)

[0078] FIG. 4a is a schematic flowchart illustrating a TMD selective growth method according to one embodiment of the present invention.

[0079] Referring to FIG. 4A, in step S1, a base substrate is prepared. The base substrate may be composed of a first material or may have a first material layer on its surface. For example, the first material layer may be formed by thermal oxidation of a Si substrate. If necessary, the first material layer may be patterned using a photolithography and etching process.

[0080] In step S2, a second material is deposited on the base substrate to form a second material layer. The first material and the second material are selected so as to enable selective growth of TMDs. For example, under growth conditions of TMDs, TMDs are grown on the first material, but TMDs are not grown on the second material. The first material may be selected from, for example, AlOx, SiNx, SiOx, TiNx, TiOx, AlNx, MoOx, SiOxNy, TiOxNy, AlOxNy, etc., and the second material may be selected from, but is not necessarily limited to, HfOx, ZrOx, TaOx, LaOx, etc. Here, x is for including a case where the stoichiometric ratio is not correct, and has a value in the range of about 1 to about 2. When the stoichiometric ratio is correct, the above materials may be expressed as SiO2, Si3N4, Al2O3, ZrO2, HfO2, etc., respectively.

[0081] In step S3, the second material layer is patterned. For example, the second material layer can be patterned using a photolithography or etching technique. Accordingly, the surface of the base substrate or the first material layer is exposed. By patterning the second material layer, a pocket surrounded by the second material layer can be formed. Accordingly, a template, such as described with reference to FIG. 2A or FIG. 2B, is manufactured. The template is a substrate having a defined growth region for growing TMDs, and is placed in a growth device, such as described with reference to FIG. 1, for growing TMDs.

[0082] In step S4, transition metal and chalcogen precursors are supplied into the chamber of the growth device. The transition metal and chalcogen precursors may be, for example, organometallic. The precursors may be introduced into the chamber of the growth device using a carrier gas. Along with the precursors, a promoter and an oxidizer may also be introduced into the chamber.

[0083] In step S5, a TMD film is grown on the template. The grown TMD film may be a single crystal monolayer, a double layer, or a triple layer. By controlling the growth time, a multilayer TMD film can be grown. When the TMD film is used as the channel layer of a transistor, it is preferable that the TMD film be three or fewer layers thick, as a semiconductor.

[0084] A substrate having a TMD capable of manufacturing an optical element or semiconductor element is provided by forming a TMD film on a template.

[0085] FIG. 4b is a schematic flowchart for explaining a TMD selective growth method according to another embodiment of the present invention.

[0086] Referring to FIG. 4b, the TMD selective growth method according to the present embodiment is generally similar to the method described with reference to FIG. 4a, except that there is a difference in depositing the first material on the base substrate.

[0087] That is, as illustrated in FIG. 4b, step S1 in the present embodiment may include a step of preparing a base substrate (S11), a step of depositing a first material (S12), and a step of patterning the first material (S13). In step S12, a first material layer is formed on the base substrate by a deposition process. The first material layer may be patterned in step S13 as needed.

[0088] (Growth selectivity of the first and second materials)

[0089] TMD films are known to have higher selectivity for certain films. For example, Figure 1D of Prior Art 1 (US2024 / 0071759A) shows the binding energies of WSe2 films and precursors for various oxide films. Based on this, it is predicted that selective growth would occur on HfO2 compared to SiO2. However, according to our experiments, we confirmed that selective growth occurred on SiO2 compared to HfO2. Therefore, we confirmed that the binding energy of TMD and oxide is not the only parameter that causes selective growth, and we compared the growth selectivity of various oxides.

[0090] Figure 5a is a SEM image showing TMD growth on the second material, which is a mask material. In this experimental example, HfO2 was used as the first material layer (23), and SiO2 was used as the second material layer (25), i.e., the mask, to form a template as shown in Figure 2a, and a TMD film was grown using MOCVD technology. Molybdenum hexacarbonyl (MHC) was used as the transition metal precursor, diethyl sulfide (DES) was used as the chalcogen precursor, and sodium propionate (SP) was used as the promoter, and the growth temperature was approximately 650°C.

[0091] Referring to Fig. 5a, it can be confirmed that the TMD film was not grown on the first material layer (23) of HfO2, but rather, the TMD film was grown on the second material layer (25) of SiO2, which is the mask material.

[0092] In contrast to FIG. 5a, FIG. 5b uses SiO2 as the first material layer (23) and HfO2 as the second material layer (25). Here, it can be confirmed that a TMD film is grown on the first material layer (23) and no TMD film is grown on the second material layer (25).

[0093] Figure 6 is a Raman spectrum showing the presence or absence of TMD growth on SiO2 and HfO2. Figure 6 also confirms that a TMD film of MoS2 is grown on SiO2, but no TMD film is grown on HfO2.

[0094] It can be seen from FIGS. 5a, 5b and 6 that the TMD film has growth selectivity depending on the types of the first material layer and the second material layer.

[0095] Figure 7a is an SEM image of a sample grown with TMD using SiNx and HfOx as the first and second materials (mask materials). Referring to Figure 7a, it can be confirmed that a TMD film is grown on SiNx, but not on HfOx.

[0096] Figure 7b is an SEM image of a sample grown with TMD using SiOx and SiNx as the first and second materials (mask materials). Referring to Figure 7b, it can be confirmed that TMD films were grown on both SiOx and SiNx.

[0097] Figure 8a is an SEM image of a sample grown on TMD using AlOx and HfOx as the first and second materials (mask materials). Referring to Figure 8a, it can be confirmed that a TMD film is grown on AlOx, but not on HfOx.

[0098] Figure 8b is an SEM image of a sample grown with TMD using SiOx and AlOx as the first and second materials (mask materials). Referring to Figure 8b, it can be confirmed that a TMD film is grown on AlOx, but not on SiOx.

[0099] Figure 8c is an SEM image of a sample grown with TMD using AlOx and SiNx as the first and second materials (mask materials). Referring to Figure 8c, it can be seen that a TMD film is grown on AlOx, but almost no TMD film is grown on SiNx.

[0100] Figure 9 is an SEM image of a sample grown with a single crystal TMD using SiOx and HfOx as the first and second materials (mask materials), respectively, and a growth pattern in which the size of the selective growth region (d) is approximately 5 μm. Here, too, it can be confirmed that a TMD film is grown on SiOx, but not on HfOx, and that single crystal MoS2 flakes are grown on the selective growth region.

[0101] Figure 10 is an SEM image of a sample grown on a single crystal TMD using a growth pattern in which a-SiO2 and a-ZrO2 were used as the first and second materials (mask materials), and the size (d) of the selective growth region was approximately 6 μm. Referring to Figure 10, it can be confirmed that a TMD film was grown on SiO2, but not on ZrO2, and that single crystal MoS2 flakes were grown on the selective growth region.

[0102] Through the above experiments, the degree of selectivity of the selective growth of TMDs for each oxide or nitride can be expressed by the following formula.

[0103] HfOx ≒ ZrOx << SiOx ≒ SiNx < AlOx

[0104] TMDs can grow more selectively on materials located on the right side of the formula than on materials located on the left side. Materials on the left side of the formula, such as HfOx or ZrOx, are more suitable as mask materials, while materials on the relatively right side, such as SiOx, SiNx, and AlOx, are more suitable for the selective growth region. However, the selectivity of the selective growth for the first and second materials of TMDs is relative between each material, and as can be seen in the examples of FIGS. 8b and 8c, the combination of materials suitable for the mask material and materials suitable for the selective growth region is not limited to the examples above.

[0105] Meanwhile, selectivity may also differ depending on the formation method of the first and second materials. Table 1 shows the selective growth trends according to the composition and formation method of the first and second materials.

[0106] Second material EBD SiO2 EBD HfO2 First material Thermal SiO2 Thermal SiO2 EBD HfO2 (20 nm) EBD SiO2 No Growth ALD HfO2 (3 nm) ALD HfO2 ALD Al2O3 (100 nm) ALD Al2O3

[0107] As the first material, SiO2 by thermal oxidation, HfO2 (20 nm) by electron beam deposition (EBD), HfO2 (3 nm) by atomic layer deposition (ALD), and Al2O3 (100 nm) by ALD were used, and as the second material, SiO2 by EBD and HfO2 by EBD were used. In Table 1, the materials for which selective growth occurred according to the combination of the first and second materials are listed, and combinations for which no results were obtained due to non-experimentation are indicated as blank.

[0108] For example, when thermally oxidized SiO2 was used as the first material and HfO2 by EBD was used as the second material, selective growth occurred in the thermally oxidized SiO2. Also, when HfO2 by EBD was used as the first material and SiO2 by EBD was used as the second material, selective growth occurred in the SiO2 by EBD. HfO by EBD was used as both the first and second materials. 2 When used, no growth of TMD occurred in either the first or second material.

[0109] Meanwhile, when TMDs were grown using HfO2 deposited by ALD and HfO2 deposited by electron beam as the first and second materials, it was confirmed that TMDs were selectively grown on HfO2 deposited by ALD even though it was the same HfO2. In other words, it can be seen that TMDs can be selectively grown by forming the first and second materials by different deposition methods, etc. even when using oxides or nitrides of the same element.

[0110] Meanwhile, when Al2O3 deposited by ALD was used as the first material and HfO2 by EBD was used as the second material, selective growth occurred in Al2O3 by ALD.

[0111] (Size and shape of the selected growth area)

[0112] Figure 11 is a set of SEM images showing the presence or absence of TMD growth depending on the size of the selected growth region under the first experimental condition. The chamber temperature was 600°C, and using a flow controller, MHC as a metal precursor was introduced into the chamber at 2 sccm, DES as a chalcogen precursor at 0.35 sccm, and SP as a promoter at 0.5 sccm. Ar as a carrier gas, H2 as a reducing agent at 5 sccm, and O2 as an oxidizing agent were introduced into the chamber at flow rates of 1000 sccm, 0.07 sccm, respectively.

[0113] Templates having circular pockets of various sizes were prepared, the templates were placed in a chamber, and MoS2 thin films were grown using MOCVD technology.

[0114] Referring to Fig. 11, it can be confirmed that under the first experimental condition, the TMD film does not grow when the radius is less than 1.99 um, and the TMD film grows in a pocket with a radius of 3.98 um.

[0115] Figure 12 shows SEM images showing the presence or absence of TMD growth depending on the size of the selected growth region under the second experimental condition. In the second experimental condition, the growth temperature was raised to 650°C compared to the first experimental condition, and the flow rates of the metal precursor (MHC 1 sccm), chalcogen precursor (DES 20 sccm), and promoter (SP: 3 sccm) were adjusted accordingly. Ar was introduced into the chamber as a carrier gas at a flow rate of 1000 sccm, H2 as a reducing agent at a flow rate of 20 sccm, and O2 as an oxidizer was not supplied.

[0116] Referring to Fig. 12, it can be confirmed that under the second experimental condition, the TMD film does not grow in pockets with a radius of 0.75 μm or less, but grows in pockets with a radius of 1.5 μm or more.

[0117] That is, according to embodiments of the present invention, it can be seen that TMD films do not grow in small pockets, for example, pockets with a diameter of 1.5 μm or less, and grow in pockets larger than a certain size, for example, larger than 2 μm. Furthermore, the pocket size in which TMD films grow can be controlled by controlling the growth temperature, precursor flow rate, type and flow rate of promoter, and oxidizing and reducing agents.

[0118] Figure 13 is a SEM image showing TMDs growing in a triangular-shaped selective growth region with a side size of approximately 2 μm. Figure 13 shows TMD films grown by increasing the DES flow rate, showing that selective growth occurs even in pockets with a side size of approximately 2 μm.

[0119] Figures 14a to 14d are SEM images showing TMDs grown within selective growth regions of various shapes.

[0120] Referring to FIGS. 14a to 14d, it can be seen that TMDs are selectively grown in all shapes, regardless of the shape of the selected growth region, such as circles, triangles, hexagons, and squares.

[0121] (Effect of growth time)

[0122] Figure 15 is a schematic diagram and SEM images showing the growth process of TMD within a selected growth region according to growth time.

[0123] Referring to Figure 15, it can be seen that as the growth time increases under the same growth conditions, nucleation and growth of a single layer occur, and then nucleation and growth occur again on the single layer, resulting in the growth of a double layer.

[0124] FIG. 16a is an SEM image of a sample in which TMDs are grown without selective growth according to a conventional technique, and FIG. 16b is an SEM image of a sample in which TMDs are grown within a selective growth region through selective growth according to one embodiment.

[0125] Referring to Fig. 16a, when a TMD film is grown on SiO2 without using a template, multiple nuclei tend to be generated and grow, forming grain boundaries, and further nuclei tend to be generated and grown at the grain boundaries. In particular, vertical growth occurs at the grain boundaries, making it difficult to form a bilayer with crystal directions aligned along the same z-axis.

[0126] Referring to Fig. 16b, when selective growth is performed by forming a pocket, a single layer is formed within the pocket, and new nuclei are generated and grown on top of it, forming a bilayer. In Fig. 16b, it can be confirmed that multiple nuclei are formed and grown on the single layer, and the TMD fragments formed on the single layer grow with generally the same crystal orientation, thereby forming a single crystal bilayer structure.

[0127] Figure 17a is a cross-sectional TEM image showing a monolayer TMD, and Figure 17b is a cross-sectional TEM image showing a multilayer TMD. Cross-sectional TEM images were obtained using samples in which monolayers and multilayers were formed over time.

[0128] Referring to Fig. 17a, as in the left image of Fig. 15, when the growth time is short, a MoS2 monolayer is formed, and the monolayer is about 0.7 nm thick.

[0129] Meanwhile, referring to Fig. 17b, as in the right image of Fig. 15, when the growth time is long, a MoS2 multilayer is formed, and the formed multilayer is three layers and has a thickness of about 2.0 nm.

[0130] (Effect of growth temperature)

[0131] Figure 18 is SEM images and Raman spectra showing whether selective growth occurs depending on the growth temperature, Figure 19 is SEM images and Raman spectra showing whether TMD growth occurs at a growth temperature of 750°C or higher, and Figure 20 is SEM images showing whether TMD growth occurs at a growth temperature near 480°C.

[0132] Referring to Fig. 18, it can be seen that a TMD film is formed on SiO2 at a temperature of 700°C or lower. However, when the temperature is 450°C, growth occurs not only on SiO2 but also on HfO2, and selective growth does not occur.

[0133] Meanwhile, referring to Fig. 19, at a growth temperature of 750°C or higher, MoS2 is not grown on SiO2 as well as HfO2.

[0134] Referring to Fig. 20, selective growth can be confirmed at 480°C or higher, and at 470°C, growth occurred not only on SiO2 but also on HfO2, so selective growth did not occur.

[0135] When the growth temperature is 750°C or higher, the transition metal precursor and chalcogen precursor may decompose prematurely in the gas phase before contacting the substrate due to the high substrate temperature. Therefore, surface growth may not occur, and thus, a TMD film may not be formed regardless of the presence of the first material layer and the second material layer. On the other hand, when the growth temperature is lower than a specific temperature, the precursor and its dispersion are easily adsorbed onto the substrate, and thus, a TMD film may be formed regardless of the presence of the first material layer and the second material layer. The TMD growth temperature can be further increased or decreased by controlling the types of the first material layer and the second material layer, the types and flow rates of source gases including the transition metal precursor and the chalcogen precursor, and the pressure in the chamber.

[0136] According to embodiments of the present invention, a single-layer, double-layer, or triple-layer TMD film having a relatively large area can be formed using a template in which pockets having a size of 2 μm or more are formed. In addition, a TMD film having good crystallinity can be provided by using selective growth, and a TMD film can be selectively grown at a desired location on a substrate. Furthermore, the TMD film can be formed using MOCVD technology, making it suitable for industrial applications. Furthermore, embodiments of the present invention can be performed at a low temperature, thereby alleviating temperature constraints in the back-end process. In addition, the TMD film can be grown on a large-area substrate, thereby reducing production costs. Furthermore, there is no restriction on the substrate, thereby reducing substrate costs. Furthermore, by growing a TMD film using a template, the number of repetitive processes of the photolithography process and the etching process can be shortened, thereby reducing process costs. Furthermore, contamination problems caused by PR residue or etching byproducts can be reduced.

[0137] In addition, by providing a substrate in which a TMD film is formed on a template in which a plurality of pockets are aligned, various optical devices and various semiconductor devices can be manufactured. Using the TMD film formed according to embodiments of the present invention, for example, a top gate FET (Top gate Field Effect Transistor), a Fin FET, an NS FET (n-channel Schottky Field-Effect Transistor), a dual gate FET, etc. can be manufactured, and a GPU core can also be manufactured. Furthermore, the TMD film can be used as a patterning mask or an etching mask, and can also be applied as a metal bonding layer, a lattice mismatch tuning layer, a GPU core, and a sacrificial layer.

Claims

1. Prepare a template with multiple optional growth areas, Including selectively growing a TMD film in the above-mentioned selected growth regions, At least one of the above selected growth regions has a size (d) of 2 μm or more, Method for selective growth of TMD.

2. In claim 1, The above template is, base board; A first material layer disposed on the substrate; and a second material layer arranged to expose at least a portion of the first material layer; A method for selective growth of TMD, wherein the selective growth regions are regions of the first material layer or regions of the second material layer.

3. In claim 2, The first material layer and the second material layer are each formed as an oxide film, a nitride film, or an oxynitride film, At least one of the elements, composition ratio, or deposition method of the first material layer is different from the elements, composition ratio, or deposition method of the second material layer, The first material layer and the second material layer have different selectivities for TMD growth, A method for selective growth of TMD, wherein TMD is selectively grown only on a material layer having high selectivity among the first material layer and the second material layer.

4. In claim 2, Among the first and second material layers, one material layer providing selective growth regions as a material layer with high selectivity for TMD is selected from the group consisting of AlOx, SiNx, SiOx, TiNx, TiOx, AlNx, MoOx, SiOxNy, TiOxNy, or AlOxNy, A method for selective growth of TMD, wherein another material layer among the first material layer and the second material layer is selected from the group consisting of HfOx, ZrOx, TaOx, or LaOx.

5. In claim 4, As a material layer with high selectivity of the above TMD, one material layer is AlOx, SiOx, or SiNx, A method for selective growth of TMD, wherein the other material layer is HfOx or ZrOx.

6. In claim 2, A method for selective growth of TMDs, wherein the selective growth regions have a negative structure or a positive structure, or the surfaces of the selective growth regions are coplanar with the surfaces of the non-growth regions surrounding them.

7. In claim 1, A method for selective growth of TMD, wherein the size (d) of at least one of the above-mentioned selective growth regions is 4 μm or more.

8. In claim 1, A method for selective growth of TMDs, wherein the above-described selective growth regions have a circular, elliptical, or polygonal shape.

9. In claim 1, A method for selective growth of TMD, wherein the above TMD film is grown using a metal-organic chemical vapor deposition method using a transition metal precursor and a chalcogen precursor.

10. In claim 9, The above-mentioned organometallic chemical vapor deposition method is a method for selective growth of TMDs using a promoter.

11. In claim 10, A method for selective growth of TMD, wherein the promoter is an organic or inorganic compound containing an alkali metal.

12. In claim 9, A method for selective growth of TMD, wherein the growth temperature is 300°C or higher and less than 750°C.

13. In claim 9, A method for selective growth of TMD, wherein the above TMD film is a single crystal and is grown in a single layer, double layer or triple layer.

14. A template having multiple selection growth areas; and Including TMD films arranged within the above-mentioned selected growth regions, A substrate having selectively grown TMDs, wherein at least one of the above selective growth regions has a size (d) of 2 μm or more.

15. In claim 14, The above template is, base board; A first material layer disposed on the base substrate; and a second material layer arranged to expose at least a portion of the first material layer; A substrate having selectively grown TMDs, wherein the selective growth regions are regions of the first material layer or regions of the second material layer.

16. In claim 15, The first material layer and the second material layer are each an oxide film, a nitride film, or an oxynitride film, The elements or composition ratio of the first material layer are different from the elements or composition ratio of the second material layer, or the first material layer is formed by a deposition method different from the deposition method of the second material layer. A substrate having selectively grown TMDs selectively arranged only on regions of the first material layer or regions of the second material layer.

17. In claim 15, One material layer providing selective growth regions among the first material layer and the second material layer is selected from the group consisting of AlOx, SiNx, SiOx, TiNx, TiOx, AlNx, MoOx, SiOxNy, TiOxNy, or AlOxNy, A substrate having selectively grown TMD, wherein another material layer among the first material layer and the second material layer is selected from the group consisting of HfOx, ZrOx, TaOx, or LaOx.

18. In claim 15, A substrate having selectively grown TMDs, wherein the selective growth regions have a negative structure or a positive structure, or the surfaces of the selective growth regions are coplanar with the surfaces of the non-growth regions surrounding them.

19. In claim 14, A substrate having selectively grown TMDs, wherein at least one of the above selective growth regions has a size (d) of 4 μm or more.

20. In claim 11, The above TMD films are single crystals, and the substrate has selectively grown TMDs in a single layer, double layer, or triple layer.

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