Substrate processing method

Abstract

A substrate processing method according to an embodiment of the present invention includes a preparation step of placing a substrate on a support table inside a chamber, a first cleaning step including a step of spraying a first cleaning gas into the inside of the chamber to remove a native oxide film on the substrate, a growth step of spraying a process gas into the inside of the chamber to grow a thin film in a growth region on one side of the substrate, and a step of generating an inductively coupled plasma inside the chamber during the first cleaning step, wherein the temperature inside the chamber is 300°C to 750°C. Therefore, according to an embodiment of the present invention, a cleaning step is performed before the growth step to remove the oxide film formed on the growth area of ​​the substrate, which makes it easier to perform a selective growth step on the substrate and improves the quality of the thin film.

Description

[Technical Field]

[0001] The present invention relates to a substrate processing method and a substrate processing apparatus, and more particularly to a substrate processing method and a substrate processing apparatus that can improve the quality of a thin film. [Background technology]

[0002] A process for manufacturing a semiconductor device includes a growth process for selectively growing an epitaxial layer on a substrate. At this time, a patterned film made of an oxide, e.g., SiO2, is formed on a portion of the upper surface of the substrate. When a process gas is sprayed, selective growth occurs in which a thin film is formed on the exposed area of ​​the upper surface of the substrate where the patterned film is not formed.

[0003] However, a native oxide film may be formed on the upper surface of the substrate while the substrate is moving or waiting before the growth process is performed. That is, a native oxide film may be formed on an exposed area of ​​the upper surface of the substrate where no pattern film is formed. Furthermore, impurities may be deposited on the pattern film during the growth process in which process gas is sprayed onto the substrate.

[0004] The native oxide film and impurities described above act as factors that hinder selective growth, which may result in failure to form a thin film with a target thickness or in a decrease in the uniformity of the thin film thickness, which may result in a decrease in the performance of the semiconductor device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Korean Patent Registration No. 10-1728072 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides a substrate processing method and a substrate processing apparatus that can improve the quality of a thin film.

[0007] The present invention provides a substrate processing method and a substrate processing apparatus that can improve the cleaning speed of a substrate. [Means for solving the problem]

[0008] A substrate processing method according to an embodiment of the present invention includes a preparation step of placing a substrate on a support table inside a chamber, a first cleaning step including a step of spraying a first cleaning gas into the chamber to remove a native oxide film on the substrate, a growth step of spraying a process gas into the chamber to grow a thin film in a growth region on one side of the substrate, and a step of generating inductively coupled plasma inside the chamber during the first cleaning step, wherein the temperature inside the chamber is 300°C to 750°C.

[0009] The first cleaning step may further include a step of spraying a second cleaning gas different from the first cleaning gas into the interior of the chamber to remove by-products produced in the step of removing the native oxide film.

[0010] The method may include a second cleaning step of spraying a second cleaning gas different from the first cleaning gas into the interior of the chamber to remove impurities remaining on one surface of the substrate.

[0011] The second cleaning step may include generating an inductively coupled plasma inside the chamber.

[0012] The substrate processing method may include a chamber cleaning step performed at least one of before the substrate is loaded into the chamber and after the substrate is unloaded from the chamber, and the chamber cleaning step may include a step of spraying the second cleaning gas into the chamber.

[0013] The chamber cleaning step may include generating an inductively coupled plasma inside the chamber.

[0014] The strength of the RF power supplied to the plasma generating unit outside the chamber for generating the inductively coupled plasma in the chamber cleaning step may be different from the strength of the RF power supplied in the first and second cleaning steps.

[0015] The growth step and second washing step may be alternately performed multiple times.

[0016] A substrate processing apparatus according to an embodiment of the present invention comprises a chamber, a support stage disposed inside the chamber so as to be capable of supporting a substrate, a plasma generating unit disposed outside the chamber so as to generate inductively coupled plasma inside the chamber, and a control unit that controls the operation of the plasma generating unit so as to generate inductively coupled plasma inside the chamber in a first cleaning step in which a first cleaning gas is sprayed into the chamber before a growth step in which a thin film is grown on the substrate, wherein the temperature inside the chamber is 300°C to 750°C.

[0017] The control unit may control the operation of the plasma generation unit so that an inductively coupled plasma is generated inside the chamber in a second cleaning step in which a second cleaning gas different from the first cleaning gas is sprayed into the chamber after the growth step.

[0018] The control unit may supply one of a first RF power source and a second RF power source having different intensities to the plasma generation unit. [Effects of the Invention]

[0019] According to an embodiment of the present invention, a cleaning step is performed before the growth step to remove an oxide film formed on the growth region of the substrate, which facilitates selective growth on the substrate and improves the quality of the thin film.

[0020] In addition, multiple growth processes are performed by spraying process gases multiple times at different times, and a cleaning process is performed between each growth process to remove impurities deposited on the pattern film, which allows for easy selective growth processes in subsequent growth processes and improves the quality of thin films.

[0021] In addition, plasma is generated inside the chamber when at least one of the cleaning processes is performed, thereby improving the speed of at least one of the cleaning processes and the cleaning efficiency, thereby improving the speed of the entire substrate processing process. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a diagram showing a substrate processing apparatus according to an embodiment of the present invention; [Figure 2] 1 is a conceptual diagram illustrating an example of a substrate to be processed by a substrate processing apparatus according to an embodiment of the present invention. [Figure 3] 1 is a flowchart showing a substrate processing method according to an embodiment of the present invention; [Figure 4] 1A to 1C are process diagrams illustrating a substrate processing method according to an embodiment of the present invention. [Figure 5] 1A to 1C are process diagrams illustrating a substrate processing method according to an embodiment of the present invention. [Figure 6] 1A to 1C are process diagrams illustrating a substrate processing method according to an embodiment of the present invention. [Figure 7] 1A to 1C are process diagrams illustrating a substrate processing method according to an embodiment of the present invention. [Figure 8] 1A to 1C are process diagrams illustrating a substrate processing method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, the embodiments of the present invention will be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. These embodiments are provided merely to complete the disclosure of the present invention and to fully convey the scope of the invention to those skilled in the art. In order to explain the embodiments of the present invention, the drawings may be exaggerated, and the same reference numerals in the drawings refer to the same components.

[0024] A substrate processing apparatus according to an embodiment of the present invention will be described below with reference to Fig. 1. In this case, the substrate processing apparatus will be described as an apparatus for selectively growing an epitaxial thin film on a substrate.

[0025] Fig. 1 is a diagram showing a substrate processing apparatus according to an embodiment of the present invention, and Fig. 2 is a conceptual diagram showing an example of a substrate to be processed by the substrate processing apparatus according to an embodiment of the present invention.

[0026] Referring to FIG. 1, a substrate processing apparatus according to an embodiment of the present invention may include a chamber 100 having an internal space, a support stage 200 arranged inside the chamber 100 so as to support a substrate S, a spraying unit 300 arranged in the chamber 100 so as to spray a gas into the chamber 100, a plasma generating unit 400 located outside the chamber 100 so as to generate plasma inside the chamber 100, and a control unit 700 for controlling the operation of the plasma generating unit 400.

[0027] The substrate processing apparatus may also include a heating section 500 arranged so that at least a portion of the heating section 500 faces the support stage 200, a driving section 600 that raises and lowers and rotates the support stage 200, and an exhaust section (not shown) that exhausts gases and impurities from inside the chamber 100.

[0028] The substrate S processed in such a substrate processing apparatus may be, for example, a wafer. More specifically, the substrate S may be a Si wafer, or, as shown in FIG. 2, may be a Si wafer on which a thin film (hereinafter, referred to as a pattern film P) made of an oxide, for example, SiO2, is formed. In other words, the substrate S may be a substrate on which a pattern film P made of SiO2 is discontinuously formed on its upper surface. This allows a portion of the upper surface of the substrate to be covered with the SiO2 pattern film P, and the remainder to be exposed.

[0029] With such a substrate S, selective growth of the thin film L is performed in the region of the upper surface where the pattern film P is not formed. The process of selectively growing the thin film L on the substrate S will be described in detail later.

[0030] The substrate S is not limited to a Si wafer, but can be variously changed to a Ge wafer, a SiGe wafer, etc. The substrate S is also not limited to a wafer, but can be variously changed to glass, plastic, film, metal, etc.

[0031] The chamber 100 may include a chamber body 110, an upper body 120 disposed on the chamber body 110, and a lower body 130 disposed below the chamber body 110. The chamber body 110 may be cylindrical with open top and bottom, or the upper body 120 may be disposed to cover the upper opening of the chamber body 110, and the lower body 130 may be disposed to cover the lower opening of the chamber body 110. The upper body 120 may be dome-shaped with a slope whose height increases toward the center in the width direction. Each of the chamber 100, i.e., the chamber body 110, the upper body 120, and the lower body 130, may be made of a transparent material that can transmit light, such as quartz.

[0032] The support stage 200 is a means for supporting the substrate S on one surface, for example, the upper surface, and may be disposed inside the chamber 100. Such a support stage 200 may be disposed to have a larger area than the substrate S, or may be disposed to have a shape corresponding to the substrate S, for example, a rectangular or circular shape. Needless to say, the support stage 200 may be disposed to have the same area as the substrate S, or to have an area smaller than the substrate S.

[0033] The driving unit 600 may be a means for moving the support table 200 by at least one of lifting and rotating. The driving unit 600 may include a driving source 610 disposed outside the lower part of the chamber 100 and providing power for at least one of lifting and rotating, and a driving shaft 620 having one end connected to the support table 200 and the other end connected to the driving source 610. With such driving unit 600, the driving shaft 620 and the support table 200 connected thereto can move by at least one of lifting and rotating due to the operation of the driving source 610.

[0034] The heating unit 500 is a means for heating the interior of the chamber 100 and the support table 200, and may be disposed outside the chamber 100. More specifically, the heating unit 500 may be disposed below the exterior of the chamber 100 so that at least a portion of the heating unit 500 faces the support table 200. Such a heating unit 500 may be a means including a plurality of lamps, and the plurality of lamps may be arranged in parallel in the width direction of the support table 200. The plurality of lamps may include halogen lamps or the like that emit radiant heat.

[0035] The spraying unit 300 sprays gas toward the substrate S placed on the support table 200 inside the chamber 100. The spraying unit 300 may be disposed in the chamber 100 such that one end of the spraying unit 300 from which the gas is sprayed is located inside the chamber 100. In this case, the spraying unit 300 may be disposed on a side of the chamber 100, for example, on the chamber body 110, as shown in FIG. 1, or may be in the form of a pipe through which the gas can pass. In addition, the spraying unit 300 may be disposed so as to be inclined upward so that its height increases as it moves toward the end from which the gas is sprayed, as shown in FIG. 1.

[0036] Needless to say, the installation position, arrangement, and shape of the spraying unit 300 are not limited to the above-mentioned example, and can be changed or modified in various ways. That is, the spraying unit 300 can be installed in any position as long as the end where the gas is sprayed faces the support table 200, and for example, it can be installed in the upper body 120 of the chamber 100. The spraying unit 300 can also be installed horizontally without being inclined upward, and is not limited to the shape of a pipe, but can be modified into various shapes that can spray gas toward the substrate S.

[0037] The gas sprayed from the spraying section 300 may be a gas for forming, depositing or growing a thin film L on the substrate S (hereinafter referred to as a process gas), or a gas for cleaning the substrate S or the inside of the chamber 100 (hereinafter referred to as a cleaning gas).

[0038] The process gas is a gas sprayed onto the substrate S to grow a thin film L, and may vary depending on the type of substrate S or the thin film to be grown. For example, if the substrate S is a Si wafer and a thin film L made of Si is to be grown on the substrate S, the process gas may be a gas containing Si. Alternatively, if the substrate S is a Ge wafer and a thin film L made of Ge is to be grown on the substrate S, the process gas may be a gas containing Ge. As another example, if the substrate S is a SiGe wafer and a thin film L made of SiGe is to be grown on the substrate S, the process gas may be a gas containing Si and a gas containing Ge. Here, the Si-containing gas may contain at least one of SiH and SiH. The Ge-containing gas may contain GeH. Note that a doping gas, for example, a gas containing B (boron), may also be sprayed via the spraying unit 300. In this case, the B (boron)-containing gas may contain, for example, BH.

[0039] On the other hand, as described above, a thin-film pattern film P made of an oxide, for example, SiO2, is formed on a portion of the upper surface of the substrate S, as shown in Fig. 2. Therefore, a portion of the upper surface of the substrate S facing the spraying unit 300 is covered with the pattern film P, and the remainder is exposed.

[0040] Here, the pattern film P made of oxide may be a masking means for hindering or preventing deposition or growth. That is, the pattern film P may be a means for selectively growing or forming a film. Therefore, when a process gas, for example, a gas containing Si2H6, is sprayed from the spraying unit 300, the Si2H6 is decomposed or dissociated by the heat inside the chamber 100, and the decomposed Si is deposited on the substrate S. That is, Si is deposited on the exposed area (hereinafter referred to as the growth area DA) on the upper surface of the substrate S where the pattern film P is not formed, and a thin film L made of Si is grown or formed. In other words, selective growth can be performed in which Si is deposited on the growth area on the upper surface of the substrate S where the pattern film P is not formed.

[0041] However, before the growth process is performed, the growth region DA of the substrate S may be oxidized, forming a thin oxide film, i.e., a native oxide, in the growth region DA. That is, the growth region DA may be oxidized and form a native oxide film while the substrate S is being moved into the chamber or while waiting outside the chamber 100. This native oxide film acts as a factor that hinders the growth or formation of a thin film. For this reason, it is necessary to remove the native oxide film formed in the growth region DA of the substrate S before the growth process is performed.

[0042] Furthermore, during the process of forming or growing a thin film L on the substrate S, impurities may remain on the pattern film P. That is, small amounts of material originating from the process gas may adhere and remain not only in the growth region DA of the substrate S but also on the pattern film P, and the material remaining on the pattern film P may act as impurities. For example, if the process gas contains Si2H6, when a thin film made of Si is deposited on the growth region DA of the substrate S, small amounts of Si may adhere and remain on the top of the pattern film P. In this way, the residue on the top of the pattern film P, i.e., Si, acts as an impurity that hinders selective growth in the subsequent growth process. For this reason, it is preferable to remove impurities such as Si remaining on the pattern film P.

[0043] Therefore, in the embodiment, before performing the growth process for growing a thin film L on the substrate S, a cleaning process (hereinafter referred to as the first cleaning process) is performed to remove the native oxide film formed in the growth area DA of the substrate S, and after the growth process, a cleaning process (hereinafter referred to as the second cleaning process) is performed to remove impurities remaining on top of the pattern film P.

[0044] In this case, the cleaning gas sprayed in the first cleaning step may contain the first cleaning gas. Also, the cleaning gas sprayed in the first cleaning step may further contain a second cleaning gas which is a gas of a substance different from the first cleaning gas. And the gas sprayed in the second cleaning step may contain the second cleaning gas. In this case, the first cleaning gas may contain SF6, and the second cleaning gas may contain Cl2.

[0045] Furthermore, when substrate processing processes are performed multiple times inside the chamber 100, by-products caused by the process gas may be generated inside the chamber 100, and these by-products may be deposited on the inner walls of the chamber 100, the surface of the support 200, etc. For example, when Si2H6 is used as the process gas, by-products made of Si may be deposited on the inner walls of the chamber 100, the surface of the support 200, etc. Such by-products may act as impurities that degrade the quality of the thin film L or the product. For this reason, it is preferable to perform a cleaning process to remove impurities inside the chamber 100.

[0046] For example, after performing the substrate processing step multiple times, before the substrate S is loaded into the chamber 100, or after the substrate S is unloaded from the chamber 100, the inside of the chamber 100 is cleaned. At this time, the inside of the chamber 100 may be cleaned by spraying a second cleaning gas containing Cl2 through the spraying unit 300.

[0047] The first cleaning step, the growth step, the second cleaning step, and the cleaning step of the chamber 100 will be described in detail later.

[0048] The plasma generator 400 is installed in the upper part of the chamber 100, i.e., on the upper part of the upper body 120, and generates plasma by ionizing gas supplied into the chamber 100. The plasma generator 400 may be a means for generating inductively coupled plasma (ICP). That is, as shown in FIG. 1, the plasma generator 400 may include an antenna having a coil 410 for inducing an electric field within the chamber 100, and a power supply 420 connected to the coil 410 for supplying RF power.

[0049] The coil 410 may be disposed on the upper part of the upper body 120. In this case, the coil 410 may be provided in a spiral shape wound with a plurality of turns, or may be configured to include a plurality of circular coils arranged in a concentric circle shape and connected to each other. Needless to say, the coil 410 is not limited to a spiral coil or a concentric circular coil, and various coils having other shapes may be applied.

[0050] Furthermore, the coil 410 may have a multi-layer structure including a lower coil disposed adjacent to the upper part of the upper body 120 and an upper coil disposed above the lower coil at a distance.

[0051] Such coil 410 may be made of a conductive material such as copper, or may be made into a hollow tubular shape. If coil 410 is made into a tubular shape, cooling water or a refrigerant can flow through it, thereby preventing the temperature of the coil from rising.

[0052] Furthermore, one end of the coil 410 may be connected to the power supply unit 420, and the other end may be connected to a ground terminal. Therefore, when RF power is supplied to the coil via the power supply unit 420, the gas blown into the chamber 100 is ionized or discharged, generating plasma inside the chamber 100.

[0053] The control unit 700 can control the operation of the plasma generating unit 400. More specifically, the control unit 700 can control the operation of the plasma generating unit 400 so that plasma is generated inside the chamber 100 in at least one of the first cleaning step and the second cleaning step.

[0054] In addition, the control unit 700 can control the plasma generating unit 400 to generate plasma inside the chamber 100 when performing a process of cleaning the inside of the chamber 100 before loading the substrate S into the chamber 100 or after unloading the processed substrate S from the chamber 100.

[0055] The control unit 700 may adjust the intensity of the RF power supplied to the power supply unit 420 of the plasma generation unit 400 during the chamber cleaning process so that it is different from the intensity of the RF power supplied during the first and second cleaning processes. For example, the control unit may adjust the intensity of the RF power supplied to the power supply unit 720 during the cleaning process so that it is greater than the intensity of the RF power supplied during the first and second cleaning processes. In other words, the control unit 700 may adjust the intensity of the first RF power supplied during the first and second cleaning processes so that it is different from the intensity of the second RF power supplied during the chamber cleaning process, and the intensity of the second RF power may be greater than the intensity of the first RF power.

[0056] Fig. 3 is a flowchart showing a substrate processing method according to an embodiment of the present invention, and Figs. 4 to 8 are process diagrams showing a substrate processing method according to an embodiment of the present invention.

[0057] 3 to 8, a substrate processing method according to an embodiment of the present invention will be described. In this case, the substrate is a Si wafer, and the description will be made by taking as an example a method of growing a thin film made of Si on a growth region of the substrate.

[0058] First, the heating unit 500 is operated to heat the support 200 to a temperature for the process (hereinafter referred to as the process temperature), for example, 550° C. When the support 200 reaches the process temperature, the substrate S is carried into the chamber 100 and placed on the support 200 (preparation step).

[0059] Before or after the substrate S is placed on the support table 200, the pressure inside the chamber 100 can be set or controlled to a pressure range of several mTorr or less, several tens of mTorr or less, or several hundred mTorr or less. In at least one of the first cleaning step (S100), the growth step (S200), and the second cleaning step (S300), the pressure inside the chamber 100 can be set or controlled to a pressure range of several mTorr or less, several tens of mTorr or less, or several hundred mTorr or less.

[0060] Furthermore, before the substrate S is placed on the support table 200 or after the substrate S is placed on the support table 200, the temperature inside the chamber 100 can be set or controlled to 300°C to 750°C (300°C or higher and 750°C or lower), preferably 400°C to 600°C (400°C or higher and 600°C or lower). In at least one of the first cleaning step (S100), the growth step (S200), and the second cleaning step (S300), the temperature inside the chamber 100 can be set or controlled to 300°C to 750°C, preferably 400°C to 600°C. In this case, the temperature inside the chamber 100 can be set or controlled using the heating unit 500.

[0061] Once the substrate S is placed on the support stage 200, a first cleaning process (S100) is performed, which includes a process (S110) of removing a native oxide film NO formed on the substrate S. To this end, as shown in FIG. 4, a first cleaning gas, for example, a gas containing SF6, is sprayed via the spray unit 300. Furthermore, RF power is supplied to the power supply unit 720 of the plasma generation unit 400 via the control unit 700 to generate plasma inside the chamber 100. At this time, the control unit 700 can adjust the strength of the RF power, i.e., the power, supplied to the coil 410 via the power supply unit 420 to be, for example, 60 W to 1000 W.

[0062] When the first cleaning gas containing SF6 is sprayed into the chamber 100, the heat inside the chamber 100 generated by the support 200 and the plasma generated by the plasma generator 400 cause the SF6 and the natural oxide film NO to react with each other. That is, the SF6 reacts with the oxygen (O) in the natural oxide film NO to generate SO2. The reaction product, SO2, can then be exhausted to the outside via the exhaust unit. As a result, the natural oxide film NO formed on the substrate S is removed.

[0063] In this way, when the first cleaning gas containing SF is sprayed into the interior of the chamber 100, not only the native oxide film NO formed on the growth region DA of the substrate S but also the pattern film P made of oxide may react with the first cleaning gas. As a result, a portion of the pattern film P may also be etched by the first cleaning gas. However, because the native oxide film NO is very thin and the pattern film P is thick, only a small portion of the pattern film P may be etched by the first cleaning gas. Therefore, when the native oxide film NO formed on the growth region DA is removed by the first cleaning gas, the pattern film P remains (see FIG. 5).

[0064] Thus, in this embodiment, the plasma generator 400 is operated to generate plasma while spraying the first cleaning gas into the chamber 100. That is, in addition to heating the support 200 inside the chamber 100, plasma is also generated inside the chamber 100. When plasma is generated inside the chamber 100, the reaction rate between the first cleaning gas and the native oxide film NO is increased. That is, when plasma is generated, the decomposition rate of SF is faster than when plasma is not generated, and therefore the reaction rate with the native oxide film NO is faster. Therefore, when plasma is generated, the reaction rate can be improved compared to when plasma is not generated. This shortens the time required for the first cleaning process to remove the native oxide film NO formed in the growth region DA of the substrate S, and improves cleaning efficiency.

[0065] Meanwhile, in the process of removing the native oxide film (S110), when the first cleaning gas reacts with the native oxide film, a reaction by-product containing a component decomposed from the first cleaning gas may be generated. That is, when SF of the first cleaning gas reacts with NO of the native oxide film to generate SO, fluorine (F) is decomposed from the first cleaning gas, and as a result, a reaction by-product containing fluorine (F) may remain inside the chamber 100. The fluorine (F) inside the chamber 100 may degrade the quality of the thin film L or the product. For this reason, after the process of removing NO of the native oxide film (S110), it is preferable to remove the reaction by-product remaining inside the chamber 100, i.e., fluorine (F) (S120).

[0066] For this purpose, after performing the step (S110) of spraying the first cleaning gas to remove the native oxide film NO, a second cleaning gas containing Cl2 is sprayed into the interior of chamber 100 via spraying unit 300 to generate plasma, as shown in Fig. 5. At this time, control unit 7000 can adjust the power applied to coil 410 via power supply unit 420 so that it is the same as when the first cleaning gas is sprayed, and may be, for example, 60 W to 1000 W.

[0067] In this manner, when the second cleaning gas containing Cl2 is sprayed into the chamber 100, Cl2 reacts with the reaction by-product, i.e., fluorine (F), due to the heat inside the chamber 100 generated by the support 200 and the plasma generated by the plasma generator 400. Then, ClF (chlorine monofluoride) generated by the reaction between the second cleaning gas and fluorine (F) is exhausted to the outside via the exhaust unit. Therefore, the reaction by-product generated by the first cleaning gas in the process of removing the native oxide film (S110) is removed to the outside of the chamber 100 (S120).

[0068] Thus, generating plasma when the second cleaning gas is sprayed increases the reaction rate between the second cleaning gas and fluorine (F). That is, when plasma is generated, the decomposition rate of Cl2 is faster than when plasma is not generated, and therefore the reaction rate with fluorine (F) in the chamber 100 is faster. Therefore, when plasma is generated, the reaction rate can be improved compared to when plasma is not generated. This reduces the process time required to remove the reaction by-products, i.e., fluorine (F), remaining inside the chamber 100 after the first cleaning step, and improves cleaning efficiency.

[0069] After the first cleaning step is completed, a growth step (S200) is performed to form a thin film on the growth region DA of the substrate S. To this end, as shown in Fig. 6, a process gas, for example, a gas containing Si2H6, is sprayed through the spraying unit 300. At this time, Si is decomposed or dissociated from the process gas Si2H6 by the heat inside the chamber 100, and the decomposed Si is deposited on the growth region DA of the substrate S. Therefore, as shown in Fig. 6, a thin film (primary thin film L1) made of Si is formed on the growth region DA of the substrate S.

[0070] However, during the growth process of forming a thin film on the substrate S, small amounts of material from the process gas may adhere and remain not only on the growth region DA of the substrate S but also on the pattern film P. For example, when a process gas containing Si2H6 is sprayed to deposit a thin film made of Si on the growth region DA of the substrate S, small amounts of Si may adhere and remain on the top of the pattern film P. The Si remaining on the top of the pattern film P acts as an impurity in the subsequent growth process. For this reason, after the growth process is completed, a second cleaning process (S300) is performed to remove impurities I remaining on the pattern film P.

[0071] 7, a second cleaning gas, for example, a gas containing Cl2, is sprayed via spraying unit 300. Furthermore, RF power is supplied to power supply unit 420 of plasma generation unit 400 via control unit 700 to generate plasma inside chamber 100. At this time, control unit 700 controls the RF power, i.e., the power supplied to coil 410 via power supply unit 420, to be, for example, 60 W to 1000 W.

[0072] When the second cleaning gas containing Cl2 is sprayed into the chamber 100, Cl2 reacts with Si due to the heat inside the chamber 100 generated by the support 200 and the plasma generated inside the chamber 100. The reaction product SiCl4 is then exhausted to the outside via the exhaust section. As a result, the impurities I on the pattern film P are removed.

[0073] When the second cleaning gas is sprayed into the chamber 100, it may react with not only the impurities remaining on the pattern film P but also the primary thin film L1 formed in the growth region DA of the substrate S. As a result, a portion of the primary thin film L1 may also be etched by the second cleaning gas. However, because the impurities I are very thin and the primary thin film L1 is relatively thick, only a small portion of the primary thin film L1 may be etched by the second cleaning gas. Therefore, when the impurities I on the pattern film P are etched or removed by the second cleaning gas, the primary thin film L1 remains.

[0074] In this way, by generating plasma during the second cleaning process in which the second cleaning gas is sprayed to remove impurities from the upper portion of the pattern film P, the reaction rate between the second cleaning gas and the impurities I is improved. That is, when plasma is generated, the decomposition rate of Cl2 is faster than when plasma is not generated, and therefore the reaction rate with the impurities I from the upper portion of the pattern film P is faster. Therefore, when plasma is generated, the reaction rate can be improved compared to when plasma is not generated. This allows the second cleaning process time to be shortened, and the second cleaning process time can be made shorter than the process time. That is, the second cleaning process can be performed in a time shorter than the growth process time. Therefore, the cleaning efficiency can be improved, the overall process time can be shortened, and damage to the substrate or thin film that occurs during the second cleaning process can be prevented.

[0075] After the second cleaning step is completed, the growth step (S200) is performed in the same manner as described above. Therefore, as shown in FIG. 8, a second thin film L2 is formed on the first thin film L1. During the growth step (S200) of forming the second thin film L2 on the first thin film L1, impurities I may adhere to or remain on the pattern film P. Therefore, after the growth step (S200) for forming the second thin film is completed, a second cleaning step (S300) is performed in the same manner as described above.

[0076] Then, the above-described growth step (S200) and second cleaning step (S300) are alternately repeated multiple times until a thin film having a target thickness is formed on the growth region DA of the substrate S. As a result, a thin film having a target thickness is grown on the growth region DA of the substrate S, as shown in FIG.

[0077] Furthermore, as described above, after the process of forming a thin film L on a substrate S is repeated multiple times, the interior of the chamber 100 is cleaned. That is, the interior of the chamber 100 is cleaned before the substrate S is loaded into the chamber 100 or after the substrate S is unloaded from the chamber 100. To this end, a second cleaning gas containing Cl2 is sprayed into the interior of the chamber 100 via the spraying unit 300, and RF power is supplied to the power supply unit 420 of the plasma generation unit 400 to generate plasma. At this time, the control unit 700 adjusts the strength of the RF power supplied to the coil 410 via the power supply unit 420, i.e., the power, so that it is greater than the power applied during the first and second cleaning processes.

[0078] In this way, when the second cleaning gas is sprayed into the interior of the chamber 100 and plasma is generated, Cl of the second cleaning gas reacts with impurities, such as Si, remaining inside the chamber 100. The reaction product, SiCl, is then exhausted to the outside via the exhaust section, thereby removing the impurities inside the chamber 100. In other words, the interior of the chamber 100 is cleaned.

[0079] As described above, according to the substrate processing method of the embodiment, a first cleaning step is performed before the growth step to remove the native oxide film NO formed on the growth region DA of the substrate S. This makes it possible to easily perform a selective growth step on the substrate S, thereby improving the quality of the thin film.

[0080] In addition, when performing multiple growth processes by spraying the process gas multiple times at different times, a second cleaning process is performed between each growth process to remove impurities I remaining on the pattern film P. This makes it possible to easily perform a selective growth process in the subsequent growth process, thereby improving the quality of the thin film.

[0081] When at least one of the first cleaning step and the second cleaning step is performed, plasma is generated inside the chamber 100. This makes it possible to improve the speed of at least one of the first cleaning step for removing the native oxide film on the substrate S and the second cleaning step for removing the impurities on the pattern film P, thereby improving the cleaning efficiency. This makes it possible to improve the speed of the entire substrate processing process.

[0082] Furthermore, when performing at least one of the first cleaning step, the growth step, and the second cleaning step, the pressure inside the chamber 100 can be set or controlled to a pressure range of several mTorr or less, or several tens of mTorr or less, or several hundred mTorr or less. Therefore, at least one of the first cleaning step, the second cleaning step, and the growth step can be easily performed at a lower temperature than conventionally. Furthermore, by setting or controlling the pressure inside the chamber 100 to a pressure range of several mTorr or less, or several tens of mTorr or less, or several hundred mTorr or less, the concentration of impurities such as oxygen inside the chamber 100 can be reduced, thereby improving the quality of the thin film. [Industrial Applicability]

[0083] According to an embodiment of the present invention, a cleaning step is performed before the growth step to remove an oxide film formed on the growth region of the substrate, which facilitates selective growth on the substrate and improves the quality of the thin film.

Claims

1. a preparation step of placing a substrate on a support inside the chamber; a first cleaning step including a step of spraying a first cleaning gas into the inside of the chamber to remove a native oxide film on the substrate, and a step of spraying a second cleaning gas different from the first cleaning gas into the inside of the chamber to remove by-products generated in the step of removing the native oxide film; a growth step of spraying a process gas into the chamber after the first cleaning step to grow a thin film on a growth region in one side of the substrate; a second cleaning step of spraying a second cleaning gas different from the first cleaning gas into the chamber after the growth step to remove impurities remaining on one side of the substrate, the first cleaning step includes generating an inductively coupled plasma inside the chamber; The method for processing a substrate, wherein the temperature inside the chamber is 300°C to 750°C.

2. 2. The method of claim 1, wherein the second cleaning step includes the step of generating an inductively coupled plasma inside the chamber.

3. a chamber cleaning step performed at least one of before the substrate is carried into the chamber and after the substrate is carried out of the chamber; The substrate processing method according to claim 2 , wherein the chamber cleaning step includes a step of spraying the second cleaning gas into the inside of the chamber.

4. 4. The method of claim 3, wherein the chamber cleaning step includes the step of generating an inductively coupled plasma inside the chamber.

5. 5. The substrate processing method of claim 4, wherein the intensity of the RF power supplied to a plasma generating unit outside the chamber for generating inductively coupled plasma in the chamber cleaning step is different from the intensity of the RF power supplied in the first and second cleaning steps.

6. The substrate of claim 1 , wherein the growth step and the second cleaning step are alternately performed multiple times. How to process.

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