Method for depositing thin film

Abstract

What is provided is a thin film deposition method for depositing a thin film on a substrate. The thin film deposition method includes supplying a source gas and a first diffusion gas together to a substrate provided in a process space, and supplying a reactant gas and a second diffusion gas together to the substrate in response to the supply of the source gas. The first diffusion gas and the source gas, as well as the second diffusion gas and the reactant gas, are supplied to the substrate through different paths from each other.

Description

Technical Field

[0001] This disclosure relates to a thin film deposition method, and more particularly to a thin film deposition method performed to deposit a thin film on a substrate. Prior Technology

[0002] For example, metal oxide thin films, such as organometallic oxide thin films, have excellent characteristics of low power and high mobility, and are used as semiconductor elements, protective layers, transparent conductive layers or semiconductor layers disposed on display devices or solar cells.

[0003] Metal oxide thin films may contain zinc (Zn) oxides doped with at least one of indium (In) or gallium (Ga), such as indium zinc oxide (IZO), gallium zinc oxide (GZO), indium gallium zinc oxide (IGZO), etc., and such metal oxide deposited thin films have various properties depending on the composition ratio of indium (In), gallium (Ga), and zinc (Zn).

[0004] According to related technologies, metal oxide thin films are deposited through an atomic layer deposition (ALD) process. In the ALD process, multiple process cycles are performed, including supplying a source gas containing indium (In), gallium (Ga), and zinc (Zn), purging this source gas, supplying a reaction gas containing oxygen (O), and purging this reaction gas, to form a metal oxide thin film on a substrate.

[0005] However, when depositing metal oxide thin films using atomic layer deposition (ALD) as described above, there is a drawback in that a significant amount of time is spent in the processes of purging the source gases and purging the reactant gases during film deposition. Specifically, the increased time spent purging the source and reactant gases, and the increased time spent readjusting the substrate temperature after purging, leads to a deterioration in productivity due to the increased time required for the film deposition process.

[0006] [Previous Technical Documents]

[0007] [Patent Documents]

[0008] (Patent Document 1) KR10-2009-0099140 A Summary of the Invention

[0009] This disclosure provides a thin film deposition method that can improve process speed.

[0010] According to an exemplary embodiment, the thin film deposition method includes: supplying a source gas and a first diffusion gas together to a substrate provided in a process space; and supplying a reaction gas and a second diffusion gas together to the substrate to continue the supply of the source gas, wherein the first diffusion gas and the source gas, and the second diffusion gas and the reaction gas are supplied to the substrate through paths different from each other.

[0011] The first diffuser gas can mix with the source gas in the path through which the source gas is supplied, and the second diffuser gas can mix with the reactant gas in a path through which the source gas is supplied.

[0012] In the supply of source gas, the supply amount of the first diffusion gas can be controlled to be different from the supply amount of the second diffusion gas.

[0013] In the supply of source gas, the supply of the first diffusion gas can be controlled to be relatively less than the supply of the second diffusion gas.

[0014] In the supply of source gas, the second diffusion gas can be supplied to the substrate together with the first diffusion gas and the source gas, and in the supply of reaction gas, the first diffusion gas can be supplied to the substrate together with the second diffusion gas and the reaction gas.

[0015] The supply of the first diffusion gas can be controlled in different ways in the supply of the source gas and the supply of the reaction gas.

[0016] The supply of the first diffusion gas in the supply of source gas can be controlled to be relatively less than the supply of the first diffusion gas in the supply of reaction gas.

[0017] In the supply of reactive gases, a power source can be applied in the process space to generate plasma.

[0018] The process can be repeated multiple times, including the supply of source gas and the supply of reaction gas.

[0019] Each of the first and second diffuse gases may contain non-reacting gases.

[0020] The source gas may contain at least one of indium (In), gallium (Ga), or zinc (Zn), and the reaction gas may contain a gas containing oxygen (O).

[0021] According to another exemplary embodiment, a method for depositing a thin film includes: a first process of supplying a first diffusion gas and a source gas through a first gas supply path formed in a gas jet section and supplying a second diffusion gas through a second gas supply path formed in the gas jet section; and a second process of supplying the first diffusion gas through the first gas supply path and supplying the second diffusion gas and a reactant gas through the second gas supply path, wherein a process cycle of continuously performing the first process and the second process is repeatedly performed. Simple Explanation of the Diagram

[0022] Exemplary embodiments may be understood in more detail through the following description in conjunction with the accompanying drawings, in which: Figure 1 is a schematic diagram illustrating a deposition apparatus according to an exemplary embodiment. Figure 2 is a schematic diagram illustrating a thin film deposition method according to an exemplary embodiment. Figure 3 is a diagram used to explain the process cycle in a thin film deposition method according to an exemplary embodiment. Figure 4 is a diagram illustrating the supply amounts of the first diffusion gas and the second diffusion gas according to an exemplary embodiment. Figure 5 is a schematic diagram illustrating the shape of a thin-film transistor manufactured according to an exemplary embodiment. Implementation

[0023] Exemplary embodiments of the invention will now be described in detail with reference to the accompanying drawings. However, the invention may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided instead to make this disclosure thorough and complete, and to fully convey the scope of the invention to those skilled in the art. In the drawings, the dimensions and areas of the layers are exaggerated for clarity. Similar reference numerals throughout refer to similar elements. This is the format that can be used when changing paragraphs within the same paragraph number. In principle, if the original text belongs to different paragraphs, it should be changed to a new paragraph and given a new paragraph number. Except in special circumstances, paragraph changes within the same paragraph should not be used.

[0024] Figure 1 is a schematic diagram illustrating a deposition apparatus according to an exemplary embodiment.

[0025] Referring to FIG1, the deposition apparatus in the exemplary embodiment is an apparatus for depositing a thin film such as a metal oxide thin film on a substrate, and includes a cavity 10, a substrate support provided in the cavity 10 to support the substrate S provided in the cavity 10, a gas jetting section 30 provided in the cavity 10 to face the substrate support 20 and jet process gas onto the substrate support 20, and a radio frequency power source 70 that applies power to the cavity 10 to generate plasma.

[0026] Furthermore, the deposition apparatus may further include a first gas supply unit 50 that supplies source gas and a first diffusion gas to the gas injection unit 30, and a second gas supply unit 60 that supplies reactant gas and a second diffusion gas to the gas injection unit 30. It may also further include supply pipes 40 for connecting the respective first gas supply units 50 and second gas supply units 60 to the gas injection unit 30. Additionally, the deposition apparatus may further include a controller (not shown) that controls the supply amounts of the first diffusion gas and source gas from the first gas supply unit 50, the supply amounts of the second diffusion gas and reactant gas from the second gas supply unit 60, and a radio frequency power source 70.

[0027] Herein, a first gas supply path through which the first gas (such as source gas and first diffusion gas) received from the first gas supply unit 50 and supplied to the substrate S passes, and a second gas supply path through which the second gas (such as reaction gas and second diffusion gas) received from the second gas supply unit 60 and supplied to the substrate S passes, are independently provided in the gas injection unit 30.

[0028] The cavity 10 provides a pre-defined process space and maintains a seal. The cavity 10 may include a body 12 having a plane with an approximately circular or square shape and sidewalls extending upward from the plane, and a cover 14 having an approximately circular or square shape and disposed on the body 12 to seal the cavity 10. However, the cavity 10 is not limited to this and can be manufactured in various shapes corresponding to the shape of the substrate.

[0029] An exhaust port (not shown) can be provided on a predetermined area of ​​the bottom surface of the cavity 10, and an exhaust pipe (not shown) connected to the exhaust port can be provided outside the cavity 10. Furthermore, the exhaust pipe can be connected to an exhaust device (not shown). A vacuum pump, such as a turbomolecular pump, can be used as the exhaust device. Therefore, the interior of the cavity can be evacuated to a predetermined reduced pressure atmosphere, such as a predetermined pressure less than or about 0.1 millitorr, by means of the exhaust device. Exhaust pipes can be installed not only on the bottom surface of the cavity 10, but also on the side surface of the cavity 10 below the substrate support 20 described later. Furthermore, multiple exhaust pipes and corresponding exhaust devices can be installed to reduce exhaust time.

[0030] A substrate provided to the cavity 10 for the thin film forming process is disposed on the substrate support 20. Here, a transparent substrate can be used as the substrate S. For example, when implementing a flexible display, a silicon substrate, glass substrate, or plastic substrate can be used as the substrate S. Furthermore, a reflective substrate can be used as the substrate S, and in this case, a metal substrate can be used. The metal substrate can be made of stainless steel (SUS), titanium (Ti), molybdenum (Mo), or alloys thereof. When a metal substrate is used as the substrate S, an insulating film can be disposed on this metal substrate. The substrate support 20 may include an electrostatic chuck to attract and hold the substrate S using electrostatic force, thereby setting and supporting the substrate S. Alternatively, the substrate support 20 may support the substrate S by vacuum adsorption or mechanical force.

[0031] The substrate support portion 20 may be provided in a shape corresponding to the substrate S, such as a circular or rectangular shape. The substrate support portion 20 may include a substrate support member 22 for mounting the substrate S and a lifter 24 disposed below the substrate support member 22 to raise and lower the substrate support member 22. Here, the substrate support member 22 may be manufactured larger than the substrate S, and the lifter 24 may be provided to support at least one region of the substrate support member 22, such as the central portion. When the substrate S is mounted on the substrate support member 22, the substrate support member 22 can move to approach the gas injection portion 30. Furthermore, a heater (not shown) may be installed in the substrate support member 22. The heater generates heat reaching a preset temperature to heat the substrate support member 22 and the substrate S mounted on the substrate support member 22, thereby uniformly depositing a thin film on the substrate S.

[0032] The supply pipe 40 can be installed through the cover 14 of the cavity 10 and can extend to connect the gas injection section 30, the first gas supply section 50, and the second gas supply section 60 to each other. Here, the supply pipe 40 may include a first supply pipe 42 communicating the space between the top surface of the upper frame 32 (described later) and the first gas supply section 50, and a second supply pipe 44 communicating the space between the top surface of the lower frame 34 (described later) and the bottom surface of the upper frame 32 to the second gas supply section 60.

[0033] The first gas supply unit 50 supplies the source gas and the first diffusion gas together to the gas injection unit 30 through the first supply pipe 42. Here, the first gas supply unit 50 may include a source gas supply unit 52 for supplying the source gas and a first diffusion gas supply unit 54 for supplying the first diffusion gas. In this case, the source gas supply unit 52 may be connected to one end of the first supply pipe 42, and the first diffusion gas supply unit 54 may be connected to an extension path of the first supply pipe 42 that connects the gas injection unit 30 to the source gas supply unit 52. The source gas may include a source gas for forming a metal oxide thin film, such as a gas containing at least one of indium (In), gallium (Ga), or zinc. Furthermore, the first diffusion gas may include a non-reactive gas for diffusing the source gas, such as argon (Ar) or nitrogen (N2). Although FIG1 illustrates a source gas supply unit 52 for ease of explanation, the source gas supply unit 52 may not need to provide a single gas, and therefore may provide various indium (In), gallium (Ga), and zinc (Zn) gases, or a gas selected from a variety of gases.

[0034] The second gas supply unit 60 supplies the reactant gas and the second diffusion gas together to the gas injection unit 30 through the second supply pipe 44. Here, the second gas supply unit 60 may include a reactant gas supply unit 62 for supplying the reactant gas and a second diffusion gas supply unit 64 for supplying the second diffusion gas. In this case, the reactant gas supply unit 62 may be connected to one end of the second supply pipe 44, and the second diffusion gas supply unit 64 may be connected to an extension path of the second supply pipe 44 that connects the gas injection unit 30 to the reactant gas supply unit 62. The reactant gas may include a reactant gas used to form a metal oxide thin film, for example, a gas containing oxygen (O). Furthermore, the second diffusion gas may include a non-reactant gas that diffuses the reactant gas, such as argon (Ar) or nitrogen (N2).

[0035] The gas injection section 30 is installed inside the cavity 10, for example, on the bottom surface of the cover 14. A first gas supply path that injects and supplies the source gas and the first diffusion gas to the substrate S, and a second gas supply path that injects and supplies the reactant gas and the second diffusion gas to the substrate S are provided in the gas injection section 30. The first gas supply path 110 and the second gas supply path 210 can be provided to be independently separated from each other so that the first gas and the second gas are separated from each other in the gas injection section 30 and do not mix with each other, and are then supplied to the substrate S.

[0036] The gas injection unit 30 may include an upper frame 32 and a lower frame 34. The upper frame 32 is detachably coupled to the bottom surface of the cover 14, and a portion of the top surface 310 of the upper frame (such as the central portion of the top surface 310) is separated from the bottom surface of the cover 14 by a predetermined distance. Therefore, the source gas supplied by the first gas supply unit 50 and the first diffuser can be diffused into the space between the top surface of the upper frame 32 and the bottom surface of the cover 14. Furthermore, the lower frame 34 is installed to be separated from the bottom surface of the upper frame 32 by a predetermined distance. Therefore, the reaction gas and the second diffused gas supplied by the second gas supply unit 60 can be diffused into the space between the top surface of the lower frame 34 and the bottom surface of the upper frame 32. The upper frame 32 and the lower frame 34 may be connected to each other along their outer peripheral surfaces to define a partition space therein and are integrated with each other, and may have a structure that seals the outer peripheral surfaces by independent seals.

[0037] In the first gas supply path 110, the source gas and the first diffusion gas supplied by the first gas supply unit 50 can diffuse into the space between the bottom surface of the cover 14 and the upper frame 32, passing through the upper frame 32 and the lower frame 34 and then being supplied into the cavity 10. Furthermore, in the second gas supply path 210, the reaction gas and the second diffusion gas supplied by the second gas supply unit 60 can diffuse into the space between the bottom surface of the upper frame 32 and the top surface of the lower frame 34, passing through the lower frame 34 and then being supplied into the cavity 10. The first gas supply path and the second gas supply path may not be connected to each other. Therefore, the source gas and the first diffusion gas, as well as the reaction gas and the second diffusion gas, can be supplied through different paths within the cavity 10.

[0038] The first electrode 38 can be mounted on the bottom surface of the lower frame 34, and the second electrode 36 can be mounted below the lower frame 34 and separated from the lower frame 34 by a predetermined distance, and mounted outside the first electrode 38 and separated from the first electrode 38 by a predetermined distance. In this case, the lower frame 34 and the second electrode 36 can be configured to be connected along the outer peripheral surface and have a structure in which the outer peripheral surface is sealed by an independent seal.

[0039] As described above, when the first electrode 38 and the second electrode 36 are installed, the source gas and the first diffusion gas can pass through the first electrode 38 and be sprayed onto the substrate, and the reaction gas and the second diffusion gas can be sprayed onto the substrate through the separation space between the first electrode 38 and the second electrode 36.

[0040] Therefore, radio frequency power can be applied to either the lower frame 34 or the second electrode 36 by the radio frequency power source 70. In FIG1, an exemplary structure is illustrated in which the lower frame 34 is grounded and radio frequency power is applied to the second electrode 36. When the lower frame 34 is grounded, the first electrode 38 mounted on the bottom surface of the lower frame 34 is also grounded. Therefore, when the radio frequency power source 70 is applied to the second electrode 36, a first excitation region (i.e., a first plasma region) is formed between the gas jet portion 30 and the substrate support portion 20, and a second excitation region (i.e., a second plasma region) can be formed between the first electrode 38 and the second electrode 36.

[0041] Therefore, when the reactive gas and the second diffusion gas are injected through the separation space between the first electrode 38 and the second electrode 36, the reactive gas is excited in the separation space between the first electrode 38 and the second electrode 36 inside the corresponding gas injection section 30, that is, excited in the region from the second plasma region to the first plasma region. Therefore, in the deposition apparatus according to the exemplary embodiment, the reactive gas can be excited inside the gas injection section 30 so as to be injected onto the substrate. Furthermore, since the first gas supply path for supplying the source gas and the first diffusion gas and the second gas supply path for supplying the reactive gas and the second diffusion gas are provided to be separate from each other, the reaction between the source gas and the reactive gas in the gas injection section 30 can be prevented, and the source gas and the reactive gas are distributed and injected to the optimal supply paths for depositing the source gas and the reactive gas.

[0042] Hereinafter, a thin film deposition method according to an exemplary embodiment will be described in detail with reference to FIG2 and FIG3. In the description of the thin film deposition method according to the exemplary embodiment, descriptions that are repeated in the description of the deposition apparatus described above will be omitted.

[0043] Figure 2 is a schematic diagram illustrating a thin film deposition method according to an exemplary embodiment. Figure 3 is a diagram for explaining the process cycle in the thin film deposition method according to an exemplary embodiment, and Figure 4 is a diagram illustrating the supply amounts of the first diffusion gas and the second diffusion gas according to an exemplary embodiment.

[0044] Referring to Figures 2 to 4, the thin film deposition method according to an exemplary embodiment includes a process (process S100) of supplying a source gas and a first diffusion gas together to a substrate S provided in a process space, and a process (process S200) of supplying a reactant gas and a second diffusion gas together to the substrate S to continue supplying the source gas. Here, in the thin film deposition method according to the exemplary embodiment, the first diffusion gas and the source gas, and the second diffusion gas and the reactant gas are supplied to the substrate S through different paths. Furthermore, the process cycle including the supply of the source gas (process S100) and the supply of the reactant gas (process S200) can be performed multiple times.

[0045] That is, in the thin film deposition method according to the exemplary embodiment, the existing process of blowing out the source gas and the reaction gas in the atomic layer deposition process is omitted. Therefore, a process cycle including the process of supplying the source gas (process S100) and the process of supplying the reaction gas (process S200) can be repeated to form a thin film with the desired thickness on the substrate S.

[0046] Therefore, when only the process of blowing off the source gas and the process of blowing off the reaction gas in the existing atomic layer deposition process are omitted, the source gas may not be uniformly adsorbed on the substrate S, thus degrading the deposition uniformity. Furthermore, the reaction gas may react with the source gas remaining in the gas jet section 30 while the reaction gas is being supplied, thus generating a large number of particles in the gas jet section 30.

[0047] Therefore, in an exemplary embodiment, the source gas and a first diffusion gas for moving the source gas can be supplied to the substrate S together, and the reactant gas and a second diffusion gas for moving the reactant gas can be supplied to the substrate S together. Furthermore, the first diffusion gas and the source gas, and the second diffusion gas and the reactant gas, can be supplied to the substrate via different paths to prevent the source gas and the reactant gas from reacting with each other beforehand. This allows for the adsorption of the source gas and the reaction generated by the reactant gas on the substrate S to form a thin film with the same quality as a thin film formed by a conventional atomic deposition process.

[0048] That is, as described above, a first gas supply path for supplying the source gas and the first diffusion gas to the substrate S and a second gas supply path for supplying the reactant gas and the second diffusion gas to the substrate S can be formed separately in the gas injection section 30. Therefore, the source gas and the reactant gas are separated from each other and will not react with each other before being injected by the gas injection section 30. Furthermore, the source gas and the first diffusion gas for controlling the movement of the source gas are supplied through the first gas supply path, and the reactant gas and the second diffusion gas for controlling the movement of the reactant gas are supplied through the second gas supply path. Therefore, in the process of supplying the source gas (process S100), the source gas can be quickly discharged to the outside of the cavity 10 through the process space by the first diffusion gas, and in the process of supplying the reactant gas (process S200), the reactant gas can be quickly discharged to the outside of the cavity 10 through the process space to minimize the reaction between the source gas and the reactant gas that remain in the process space even after being injected from the gas injection section 30. Hereinafter, a thin film deposition method according to an exemplary embodiment that can achieve the above technical effects will be described in detail.

[0049] The substrate S preparation process can be performed before the process of supplying the source gas (process S100). In the substrate S preparation process, the substrate S is loaded into the cavity 10 of the deposition apparatus and placed on the substrate support 20. Here, the substrate S can be a substrate for manufacturing thin-film transistors and can include, for example, a silicon substrate, a glass substrate, or a plastic substrate. The thin-film transistor manufactured using the prepared substrate S will be described in detail below with reference to FIG5.

[0050] In the process of supplying the source gas (process S100), the source gas and the first diffusion gas are supplied together to the substrate S provided in the process space within the cavity 10. Here, the source gas is supplied by the source gas supply unit 52 of the aforementioned deposition apparatus and is supplied to the substrate S through the first gas supply path provided in the gas jet unit 30. Furthermore, the first diffusion gas is supplied by the first diffusion gas supply unit 54 and is supplied to the substrate S through the first gas supply path provided in the gas jet unit 30.

[0051] Here, the source gas supply unit 52 can be connected to one end of the first supply pipe 42, and the first diffusion gas supply unit 54 can be connected to an extension path of the first supply pipe 42 that connects the gas injection unit 30 to the source gas supply unit 52 while being separated from the source gas supply unit 52. Therefore, the first diffusion gas can be mixed with the source gas in the first gas supply path and supplied to the substrate S. As described above, the first diffusion gas can be mixed with the source gas in the first gas supply path and supplied to the substrate S, and therefore, unlike a carrier gas that is pre-mixed with the source gas and only used to transport the source gas, the first diffusion gas can not only control the movement of the source gas, but can also be used to diffuse the source gas on the substrate S.

[0052] Here, the source gas may include a source gas used to form a metal oxide thin film. For example, the source gas may be a gas containing at least one of indium (In), gallium (Ga), or zinc (Zn). Furthermore, the first diffusion gas may include a non-reactive gas for diffusing the source gas, such as argon (Ar) or nitrogen (N2). A source gas supply unit 52 may not need to provide a source gas and may provide individual indium (In), gallium (Ga), and zinc (Zn) gases, or may provide a gas selected from a variety of gases as described above.

[0053] In the process of supplying the source gas (process S100), the source gas and the first diffusion gas are supplied to the substrate S together so that the source material contained in the source gas is adsorbed onto the substrate S while the movement of the source gas is controlled. In this case, the process of supplying the source gas (process S100) can be carried out without applying a power source.

[0054] In the process of supplying the reactant gas (process S200), the reactant gas and the second diffusion gas are supplied together to the substrate S to continue the process of supplying the source gas (process S100). That is, after the process of supplying the source gas (process S100), the process of purging the source gas is not performed, and the process of supplying the reactant gas (process S200) is performed to continue the process of supplying the source gas (process S100).

[0055] In the process of supplying the reactive gas (process S200), the reactive gas and the second diffusion gas are supplied together to the substrate S on which the source gas and the first diffusion gas are sprayed. Here, the reactive gas is supplied by the reactive gas supply unit 62 of the aforementioned deposition apparatus and is supplied to the substrate S through the second gas supply path provided in the gas spray unit 30. In addition, the second diffusion gas is supplied by the second diffusion gas supply unit 64 and is supplied to the substrate S through the second gas supply path provided in the gas spray unit 30.

[0056] Here, one end of the reactive gas supply unit 62 can be connected to the second supply pipe 44, and the second diffusion gas supply unit 64 can be connected to an extension path of the second supply pipe 44 that connects the gas injection unit 30 to the reactive gas supply unit 62 while being separated from the reactive gas supply unit 62. Therefore, the second diffusion gas can be mixed with the reactive gas in the second gas supply path and supplied to the substrate S. As described above, like the first diffusion gas, the second diffusion gas can be mixed with the reactive gas in the second gas supply path and supplied to the substrate S, and therefore, unlike the carrier gas that is pre-mixed with the reactive gas and used only for transporting the reactive gas, the second diffusion gas can not only control the movement of the reactive gas, but can also be used to diffuse the reactive gas on the substrate S.

[0057] Here, the reactant gas may include a reactant gas used to form a metal oxide film by reacting with the source gas. For example, the reactant gas may be an oxygen (O) gas. In addition, the second diffusion gas may include a non-reactant gas, such as argon (Ar) or nitrogen (N2), used to diffuse the reactant gas.

[0058] Therefore, in the process of supplying the reactive gas (process S200), radio frequency power can be applied to the process space to excite the reactive gas to generate plasma, thereby allowing the oxygen (O) component contained in the reactive gas to react effectively with the zinc (Zn) component. As described above, in the process of supplying the reactive gas (process S200), the oxygen-containing gas supplied by the excitation and supply of the reactive gas can be excited by oxygen free radicals to react with the zinc component, and a zinc oxide thin film can be formed on the substrate at a relatively low process temperature.

[0059] According to an exemplary embodiment, in the process of supplying the source gas (process S100), the supply amount of the second diffusion gas and the supply amount of the first diffusion gas can be controlled in different ways. That is, in the deposition of the thin film on the substrate S, since the thickness of the thin film is determined according to the degree to which the source material is adsorbed onto the substrate S, the supply rate of the source gas supplied to the substrate S must be controlled in different ways according to the process conditions to control the thickness of the thin film. Therefore, according to an exemplary embodiment, in the process of supplying the source gas (process S100), and in the process of supplying the reaction gas (process S200), the supply amount of the second diffusion gas and the supply amount of the first diffusion gas can be controlled in different ways.

[0060] Furthermore, in the process of supplying the source gas (process S100), the supply amount of the first diffusion gas can be controlled to be relatively less than the supply amount of the second diffusion gas. That is, in the exemplary embodiment, the supply amount of the first diffusion gas in the process of supplying the source gas (process S100) can be controlled to be less than the supply amount of the second diffusion gas in the process of supplying the reaction gas (process S200).

[0061] That is, as illustrated in FIG4, in the process of supplying the source gas according to the exemplary embodiment (process S100), the supply amount of the first diffusion gas can be controlled to M1. Furthermore, in the process of supplying the reaction gas according to the exemplary embodiment (process S200), the supply amount of the second diffusion gas can be controlled to M2, which is greater than M1.

[0062] Generally, in atomic layer deposition (ALD) processes, after the source gas is supplied, it diffuses and is uniformly adsorbed onto the substrate S during a process that removes the source gas. However, if a process of removing the source gas is not performed after the source gas is supplied, the source gas cannot diffuse uniformly onto the substrate S, and therefore a large amount of source material will be adsorbed in the central part of the substrate S, while a relatively small amount of source material will be adsorbed at the edges of the substrate S, thus degrading the deposition uniformity.

[0063] Therefore, in the exemplary embodiment, the supply amount M1 of the first diffusion gas in the process of supplying the source gas (process S100) can be controlled to be relatively greater than the supply amount M2 of the second diffusion gas in the process of supplying the reaction gas (process S200). As described above, in the process of supplying the reaction gas (process S200), the supply amount M1 of the first diffusion gas is controlled to be relatively less than the supply amount M2 of the second diffusion gas. Therefore, the source gas is diffused onto the substrate S at a relatively slow rate, and thus, the source gas is uniformly diffused to the edge of the substrate S, causing the source material to be adsorbed onto the substrate S with a uniform thickness. That is, since the thickness of the film deposited on the substrate S is determined by the degree of adsorption of the source material, the deposition uniformity can be improved by controlling the supply amount M1 of the first diffusion gas to be relatively small. The reactant gas is used to provide reactants that react with the source material adsorbed on the substrate S, and in the process of supplying the source gas (process S100), the supply amount M2 of the second diffusion gas is controlled to be greater than the supply amount M1 of the first diffusion gas, so as to quickly provide reactants that react with the source material on the substrate S.

[0064] In the process of supplying the source gas (process S100), the second diffusion gas, together with the first diffusion gas and the source gas, can be supplied to the substrate S. Similarly, in the process of supplying the reaction gas (process S200), the first diffusion gas, the second diffusion gas, and the reaction gas can be supplied to the substrate S. That is, the thin film deposition method according to the exemplary embodiment may include a first process in which the first diffusion gas and the source gas are supplied to the process space of the cavity 10 through a first gas supply path formed in the gas jet section 30, and the second diffusion gas is supplied to the process space through a second gas supply path formed in the gas jet section 30. A second process in which the first diffusion gas is supplied to the process space through the first gas supply path, and the second diffusion gas and the reaction gas are supplied to the process space through the second gas supply path, are also included. Here, the first and second processes can be performed continuously to form a process cycle, and this continuous process cycle of performing the first and second processes can be repeated.

[0065] More specifically, in the process of supplying the source gas (process S100), the first diffusion gas and the source gas are supplied to the substrate S through the first gas supply path, and the second diffusion gas is simultaneously supplied to the substrate S through the second gas supply path. Furthermore, in the process of supplying the reaction gas (process S200), the second diffusion gas and the reaction gas are supplied to the substrate S through the second gas supply path, and the first diffusion gas is simultaneously supplied to the substrate S through the first gas supply path.

[0066] As described above, while the reactant gas and the second diffusion gas are supplied through the second gas supply path, the first diffusion gas can be supplied through the first gas supply path to prevent the reactant gas from being introduced into the first gas supply path, thereby preventing the generation of particulates due to the reaction between the source gas and the reactant gas in the first gas supply path. That is, while the source gas and the first diffusion gas are supplied through the first gas supply path, the second diffusion gas can be supplied through the second gas supply path to prevent the source gas from being introduced into the second gas supply path, thereby preventing the generation of particulates due to the reaction between the source gas and the reactant gas in the second gas supply path.

[0067] Furthermore, while the reactant gas and the second diffusion gas are supplied through the second gas supply path, the first diffusion gas can be supplied through the first gas supply path to quickly discharge the source gas remaining in the first gas supply path. That is, in the process of supplying the source gas (process S200), the supply of the source gas in the process of supplying the source gas (process S100) can be stopped, but the source gas that has been discharged in the process of supplying the source gas (process S100) may remain in the first gas supply path. Therefore, in the exemplary embodiment, while the reactant gas and the second diffusion gas are supplied through the second gas supply path, the first diffusion gas can be supplied through the first gas supply path to minimize the generation of impurities due to the reaction of the source gas and the reactant gas in the first gas supply path or process space. This situation can be equally applied to the situation where the second diffusion gas is supplied through the second gas supply path while the source gas and the first diffusion gas are supplied through the first gas supply path.

[0068] In this case, the first diffusion gas is continuously supplied to the substrate S in both the process of supplying the source gas (process S100) and the process of supplying the reaction gas (process S200). In this case, the supply amount of the first diffusion gas can be controlled differently in the process of supplying the source gas (process S100) and the process of supplying the reaction gas (process S200). That is, as described above, in the process of supplying the source gas (process S100), the first diffusion gas can be supplied with a supply amount M1 that is relatively less than the supply amount M2 of the second diffusion gas. This is done to uniformly distribute the source gas on the substrate. On the other hand, in the process of supplying the reaction gas (process S200), the first diffusion gas is not used to uniformly diffuse the source gas, but rather to prevent the reaction gas from being introduced into the first gas supply path. Therefore, in the process of supplying the reaction gas (process S200), the first diffusion gas can be supplied in an amount greater than M1. For example, in the process of supplying the reaction gas (process S200), the first diffusion gas can be controlled to be supplied in an amount M2 equal to the amount of the second diffusion gas, so as to effectively block the reaction gas from flowing into the first gas supply path.

[0069] Figure 4 illustrates an example where, in both the process of supplying the source gas (process S100) and the process of supplying the reaction gas (process S200), the first diffusion gas is supplied in amounts M1 and M2, respectively. Furthermore, in both processes, the second diffusion gas is supplied in an amount of M2. However, the supply amounts of the first and second diffusion gases can be controlled in various ways. For example, in the process of supplying the reaction gas (process S200), the supply amount of the first diffusion gas can be controlled to be less than or greater than M2 within a range greater than M1. Moreover, in either the process of supplying the source gas (process S100) or the process of supplying the reaction gas (process S200), the supply amounts of the first and second diffusion gases do not need to be maintained at M1 or M2. For example, the supply amounts can be changed in various ways to increase or decrease depending on the process conditions.

[0070] As described above, a process cycle including the supply of source gas (process S100) and the supply of reaction gas (process S200) can be performed multiple times until a thin film with the desired thickness is deposited. That is, in the thin film deposition method according to the exemplary embodiment, the process of purging the reaction gas may not be performed after the process of supplying the reaction gas (process S200), and the process of supplying source gas (process S100) and the process of supplying reaction gas (process S200) as a process cycle can be performed multiple times to deposit a thin film.

[0071] Figure 5 is a schematic diagram illustrating the shape of a thin-film transistor manufactured according to an exemplary embodiment.

[0072] Referring to FIG5, a thin-film transistor manufactured according to an exemplary embodiment includes a gate electrode 100, a source electrode 400 and a drain electrode 500 disposed above or below the gate electrode 100 and separated from each other in a horizontal direction, an active layer 300 disposed between the gate electrode 100, the source electrode 400 and the drain electrode 500, and a gate insulating layer 200 disposed between the gate electrode 100 and the active layer 300.

[0073] As shown in FIG5, the thin-film transistor according to the exemplary embodiment can be a bottom-gate thin-film transistor and a top-gate thin-film transistor. In the bottom-gate thin-film transistor, a gate electrode 100 is formed on the substrate S, a gate insulating layer 200 is formed on the gate electrode 100, an active layer 300 is formed on the gate insulating layer 200, and a source electrode 400 and a drain electrode 500 spaced apart from each other are formed on the active layer 300. In the top-gate thin-film transistor, unlike the bottom-gate thin-film transistor, the gate electrode 100 is disposed on the upper side.

[0074] Therefore, a transparent substrate can be used as substrate S. For example, when implementing a flexible display, a silicon substrate, a glass substrate, or a plastic substrate can be used as substrate S. Furthermore, a reflective substrate can be used as substrate S, and in this case, a metal substrate can be used. The metal substrate can be made of stainless steel (SUS), titanium (Ti), molybdenum (Mo), or alloys thereof. When using a metal substrate as substrate S, an insulating film can be disposed on the metal substrate.

[0075] The gate electrode 100 may be made of a conductive material, such as at least one metal or an alloy of aluminum (Al), rubidium (Nd), silver (Ag), chromium (Cr), titanium (Ti), tantalum (Ta), and molybdenum (Mo). Furthermore, the gate electrode 100 may be formed not only as a single layer but also as a multilayer structure comprising multiple metal layers. That is, the gate electrode 100 may be formed as a double-layer structure comprising a metal layer made of chromium (Cr), titanium (Ti), tantalum (Ta), and molybdenum (Mo) with excellent physical and chemical properties, and a metal layer made of aluminum (Al), silver (Ag), or copper (Cu) series metals with low resistivity.

[0076] The gate insulating layer 200 is formed at least on the gate electrode 100. That is, the gate insulating layer 200 can be formed on the substrate S including the top and sides of the gate electrode 100. The gate insulating layer 200 can be made of one or more insulating materials including an inorganic insulating layer of silicon dioxide (SiO2), silicon nitride (SiN), aluminum oxide (Al2O3), and zirconium oxide (ZrO2) which have excellent adhesion to metallic materials and excellent dielectric strength.

[0077] The active layer 300 is disposed between the gate insulating layer 200 and the source electrode 400 and drain electrode 500, and is configured to at least partially overlap the gate electrode 100. The active layer 300 may be formed to comprise a metal oxide thin film. As described above, the active layer 300 may be formed by a thin film deposition method comprising a process (process S200) in which a reactant gas and a second diffusion gas are supplied together to a substrate S to subsequently supply a source gas and a first diffusion gas together, and a process (process S100) in which a source gas is supplied to a substrate S provided in a process space. In this case, the thin film deposition method may be the same as the thin film deposition method described above, and therefore repeated descriptions will be omitted. In this thin film deposition method, multiple process cycles are performed, including a process for supplying source gas (process S100) and a process for supplying reaction gas (process S200), and the first diffusion gas and source gas, as well as the second diffusion gas and reaction gas, are supplied to the substrate S through different paths.

[0078] The active layer 300 can be provided as a single metal oxide thin film or multiple metal oxide thin films. Here, the conductivity of the metal oxide thin film can be adjusted by controlling the type and content of the metal element contained in each metal oxide thin film. That is, indium (In) can be a metal with a relatively low bandgap and a relatively high standard electrode potential, and therefore has the characteristic of improving mobility by reducing resistance and increasing conductivity. On the other hand, gallium (Ga) can be a metal with a relatively high bandgap and a relatively high standard electrode potential, and therefore has the characteristic of improving stability by increasing resistance and reducing conductivity. Therefore, the active layer can be formed by controlling the content of indium (In) and gallium (Ga) contained in each single metal oxide thin film or multiple metal oxide thin films. This metal oxide thin film includes at least one of indium zinc oxide (IZO; In-Zn-O) thin film, gallium zinc oxide (GZO; Ga-Zn-O) thin film, and indium gallium zinc oxide (IGZO; In-Ga-Zn-O) thin film.

[0079] Source electrode 400 and drain electrode 500 are disposed on active layer 300, partially overlapping gate electrode 100, and are separated from each other, with gate electrode 100 located between source electrode 400 and drain electrode 500. Source electrode 400 and drain electrode 500 can be formed using the same process and the same materials, and can be made of conductive materials, such as at least one metal selected from aluminum (Al), rubidium (Nd), silver (Ag), chromium (Cr), titanium (Ti), tantalum (Ta), and molybdenum (Mo), or alloys thereof. That is, gate electrode 100 can be made of the same material, but can also be made of different materials. Furthermore, each source electrode 400 and drain electrode 500 can be provided as a single-layer structure or a multilayer structure with multiple metal layers.

[0080] According to an exemplary embodiment, the process speed of depositing thin films on a substrate can be increased.

[0081] In other words, by omitting the processes of blowing out the source gas and the reaction gas in the atomic layer deposition process according to the relevant technology, the process time can be minimized.

[0082] Furthermore, even if the processes of purging the source gas and purging the reaction gas are omitted, a film with quality comparable to that formed in an atomic layer deposition process according to the relevant technology can still be formed.

[0083] While specific terms are used to describe and illustrate specific embodiments, this is merely for the purpose of clearly explaining exemplary embodiments, and therefore, it will be apparent to those skilled in the art that the exemplary embodiments and technical terms can be implemented in other specific forms without altering the technical concepts or essential features. Therefore, it should be understood that simple modifications to exemplary embodiments of the present invention are within the technical spirit of the invention.

[0084] M1, M2: Supply S:Substrate S100, S200: Manufacturing Process 10: Cavity 12: Main Body 14: Cover 20: Substrate support portion 22: Substrate support 24: Lifter 30: Gas injection section 32: Top frame 34: Bottom frame 36: Second electrode 38: First electrode 40: Supply pipe 42: First Supply Pipe 44: Second supply pipe 50: First Gas Supply Department 52: Source Gas Supply Department 54: First Diffusion Gas Supply Department 60: Second Gas Supply Department 62: Reaction Gas Supply Section 64: Second Diffusion Gas Supply Section 70: Source of Radio Frequency Power 100: Gate electrode 110: First gas supply path 200: Gate insulation layer 210: Second gas supply path 300: Active Layer 310: Top surface of the upper frame 400: Source electrode 500: Drain electrode

Claims

1. A thin film deposition method, comprising: supplying a source gas and a first diffusion gas together to a substrate provided in a process space; and supplying a reactant gas and a second diffusion gas together to the substrate to continue the supply of the source gas, wherein the first diffusion gas and the source gas, and the second diffusion gas and the reactant gas are supplied to the substrate through paths different from each other; wherein, In the supply of the source gas, the supply amount of the first diffusion gas is controlled to be different from the supply amount of the second diffusion gas.

2. The thin film deposition method as claimed in claim 1, wherein the first diffusion gas is mixed with the source gas in a path through which the source gas is supplied, and the second diffusion gas is mixed with the reactant gas in a path through which the source gas is supplied.

3. The thin film deposition method as described in claim 1, wherein, In the supply of the source gas, the supply amount of the first diffusion gas is controlled to be relatively less than the supply amount of the second diffusion gas.

4. A thin film deposition method, comprising: supplying a source gas and a first diffusion gas together to a substrate provided in a process space; and supplying a reactant gas and a second diffusion gas together to the substrate to continue the supply of the source gas, wherein the first diffusion gas and the source gas, and the second diffusion gas and the reactant gas are supplied to the substrate through different paths from each other; wherein, In the supply of the source gas, the second diffusion gas is supplied to the substrate together with the first diffusion gas and the source gas, and in the supply of the reaction gas, the first diffusion gas is supplied to the substrate together with the second diffusion gas and the reaction gas.

5. The thin film deposition method as described in claim 4, wherein, The supply of the first diffusion gas is controlled in different ways in the supply of the source gas and the supply of the reaction gas.

6. The thin film deposition method as claimed in claim 5, wherein the supply amount of the first diffusion gas in the supply of the source gas is controlled to be relatively less than the supply amount of the first diffusion gas in the supply of the reaction gas.

7. The thin film deposition method as described in claim 1 or 4, wherein, In the supply of the reactive gas, a power source is applied in the process space to generate plasma.

8. The thin film deposition method as described in claim 1 or 4, wherein one process cycle comprising the supply of the source gas and the supply of the reactant gas is performed multiple times.

9. The thin film deposition method as described in claim 1 or 4, wherein each of the first diffusion gas and the second diffusion gas comprises a non-reactive gas.

10. A thin film deposition method comprising: supplying a source gas and a first diffusion gas together to a substrate provided in a process space; and supplying a reaction gas and a second diffusion gas together to the substrate to continue the supply of the source gas, wherein the first diffusion gas and the source gas, and the second diffusion gas and the reaction gas are supplied to the substrate through paths different from each other; wherein the source gas comprises a gas containing at least one of indium (In), gallium (Ga), or zinc (Zn), and the reaction gas comprises a gas containing oxygen (O).

11. A thin film deposition method, comprising: a first process of supplying a first diffusion gas and a source gas through a first gas supply path formed in a gas jet and supplying a second diffusion gas through a second gas supply path formed in the gas jet; and a second process of supplying the first diffusion gas through the first gas supply path and supplying the second diffusion gas and the reactant gas through the second gas supply path, wherein a process cycle of repeatedly performing the first process and the second process continuously is performed.

Images