Thin film forming method, and transistor and capacitor manufactured using same

Abstract

The present invention relates to a thin film forming method, and a transistor and a capacitor which are manufactured using same and, more specifically, to a thin film forming method for forming a metal oxide thin film, and a transistor and a capacitor which are manufactured using same. The thin film forming method according to an embodiment of the present invention is a thin film forming method for forming a thin film on a substrate provided in a reaction space, by using an atomic layer deposition process in which a step of supplying a raw material gas and a step of supplying a reaction gas are sequentially performed, the method including a step of forming a dielectric layer containing a metal by performing a step of supplying a hydrogen-containing gas after at least one of the step of supplying the raw material gas and the step of supplying the reaction gas, wherein the step of supplying the hydrogen-containing gas includes a step of applying power to the reaction space.

Description

Thin film formation method and transistor and capacitor manufactured using the same

[0001] The present invention relates to a thin film forming method and a transistor and capacitor manufactured using the same, and more specifically, to a thin film forming method for forming a dielectric thin film containing a metal and a transistor and capacitor manufactured using the same.

[0002] Atomic Layer Deposition (ALD) is a well-known technology for forming thin films on substrates. It involves repeatedly depositing thin films layer by layer until they reach a desired thickness. Compared to conventional chemical vapor deposition (CVD) methods, the ALD process can produce thin films with superior step coverage and high film density.

[0003] Meanwhile, dielectric thin films containing metal are widely used in the manufacture of semiconductor devices, display devices, solar cells, etc., and are mainly used as gate insulating films of transistors and dielectric layers of capacitors.

[0004] Forming metal-containing dielectric thin films using atomic layer deposition (ALD) offers the advantages of precise thickness control, excellent step coverage, and low-temperature deposition. However, the type of precursor used as the source gas during thin film formation can vary the binding energy (potential energy) between the central element and the ligand, resulting in variations in impurity content. Furthermore, when using precursors with high binding energies as the source gas, a high-temperature process is essential for their decomposition, posing a challenge.

[0005] (Prior art literature)

[0006] Korean Patent Publication No. 10-2019-0125093

[0007] The present invention provides a thin film forming method capable of forming a dielectric thin film containing a metal having excellent properties, and a transistor and capacitor manufactured using the same.

[0008] A method for forming a thin film according to an embodiment of the present invention is an atomic layer deposition process for forming a thin film on a substrate provided in a reaction space by sequentially performing a step of supplying a raw material gas and a step of supplying a reaction gas, the method comprising: a step of supplying a hydrogen-containing gas after at least one of the steps of supplying the raw material gas and the step of supplying the reaction gas, thereby forming a dielectric layer including a metal; wherein the step of supplying the hydrogen-containing gas includes a step of applying power to the reaction space.

[0009] The step of forming a dielectric layer including a metal by performing the step of supplying the hydrogen-containing gas may include the step of supplying an oxygen-containing gas before or after supplying the hydrogen-containing gas, and the step of supplying the oxygen-containing gas may include the step of applying power to the reaction space.

[0010] The step of supplying the oxygen-containing gas is performed after the step of supplying the hydrogen-containing gas, and includes a step of further supplying the hydrogen-containing gas after the step of supplying the oxygen-containing gas; and the step of further supplying the hydrogen-containing gas may include a step of applying power to the reaction space.

[0011] The step of supplying the hydrogen-containing gas may supply the hydrogen-containing gas for a time different from the time of supplying the oxygen-containing gas.

[0012] The step of supplying the hydrogen-containing gas may supply the hydrogen-containing gas for a longer time than the time for supplying the oxygen-containing gas.

[0013] The step of supplying the raw material gas includes a step of supplying a purge gas after supplying the raw material gas, the step of supplying the reaction gas includes a step of supplying a purge gas after supplying the reaction gas, and the step of applying power to the reaction space can be performed after supplying the purge gas.

[0014] A step of forming a dielectric layer including a metal by performing a step of supplying the hydrogen-containing gas, and a step of supplying an oxygen-containing gas after at least one of the steps of supplying the raw material gas and the step of supplying the reaction gas, thereby forming a dielectric layer including a metal; wherein the step of supplying the oxygen-containing gas may include a step of applying power to the reaction space.

[0015] The step of forming a dielectric layer including a metal by performing the step of supplying the hydrogen-containing gas may be performed repeatedly multiple times.

[0016] At least one of the steps of supplying the raw material gas and the step of supplying the reaction gas may include a step of applying power to the reaction space.

[0017] The step of supplying the hydrogen-containing gas can be performed after the step of supplying the raw material gas and after the step of supplying the reaction gas.

[0018] In addition, a transistor according to an embodiment of the present invention includes a gate electrode; an active layer spaced apart from the gate electrode; a gate insulating film disposed between the gate electrode and the active layer; and source and drain electrodes disposed to be in contact with the active layer; wherein the gate insulating film includes a dielectric layer including a metal formed by any one of the above-described thin film forming methods.

[0019] In addition, a capacitor according to an embodiment of the present invention includes a first capacitor electrode; a second capacitor electrode spaced apart from the first capacitor electrode; and a dielectric layer disposed between the first capacitor electrode and the second capacitor electrode; wherein the dielectric layer includes a dielectric layer including a metal formed by any one of the above-described thin film forming methods.

[0020] According to an embodiment of the present invention, by supplying a hydrogen-containing gas onto a substrate to form a plasma while forming a thin film using an atomic layer deposition process, a dielectric thin film including a metal having a minimized content of impurities and improved film quality can be formed.

[0021] In addition, by improving the properties of a dielectric thin film containing metal, the performance of a semiconductor device containing the same can be greatly improved.

[0022] FIG. 1 is a drawing exemplarily showing a semiconductor device according to an embodiment of the present invention.

[0023] Figure 2 is a schematic drawing showing a substrate processing device according to an embodiment of the present invention.

[0024] FIG. 3 is a drawing showing a plasma formation according to an embodiment of the present invention.

[0025] Figure 4 is a drawing schematically showing a thin film forming method according to one embodiment of the present invention.

[0026] FIG. 5 is a drawing schematically showing a thin film forming method according to another embodiment of the present invention.

[0027] FIG. 6 is a schematic diagram showing a transistor according to an embodiment of the present invention.

[0028] FIG. 7 is a schematic diagram showing a capacitor according to an embodiment of the present invention.

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments of the present invention are provided solely to ensure complete disclosure of the present invention and to fully inform those skilled in the art of the scope of the invention.

[0030] When a component, such as a layer, film, region or substrate, is referred to as being "on" another component throughout the specification, it can be interpreted that the component is either directly "on" the other component, or there may be other components intervening therebetween.

[0031] Additionally, relative terms such as "upper" or "lower" may be used herein to describe the relative relationship of certain elements to other elements as depicted in the drawings. It should be understood that relative terms are intended to encompass other orientations of the elements in addition to the orientation depicted in the drawings. To illustrate the invention in detail, the drawings may be exaggerated, and like reference numerals throughout the drawings designate like elements.

[0032]

[0033] FIG. 1 is a drawing exemplarily showing a semiconductor device according to an embodiment of the present invention.

[0034] As illustrated in FIG. 1, a semiconductor device according to an embodiment of the present invention may include a memory device such as a DRAM (Dynamic Random Access Memory). DRAM is a type of volatile semiconductor memory device commonly used in electronic devices such as computers and portable terminals.

[0035] A DRAM may include a plurality of memory cells arranged in a plurality of rows and columns, wherein each memory cell may include, for example, one transistor (100) and one capacitor (200).

[0036] In this way, a DRAM may include a word line and a bit line. Here, the word line may be connected to or included in the gate line of the transistor (100) and determines whether or not the memory cell is used. On the other hand, the bit line may be connected to or included in the source electrode or drain electrode of the transistor (100) and serves to confirm the value (0 or 1) of the stored memory. For example, when a high voltage is applied to the gate electrode of the transistor (100), the capacitor (200) is charged and the memory may have a value of 1, and when a low voltage is applied to the gate electrode of the transistor (100), the capacitor (200) is discharged and the memory may have a value of 0.

[0037] Hereinafter, a method for forming a thin film according to an embodiment of the present invention will be described as an example in which it is used for manufacturing DRAM, and more specifically, for manufacturing transistors and capacitors included in DRAM. However, it should be understood that the method for forming a thin film according to an embodiment of the present invention can be applied in various ways to manufacturing not only DRAM but also other semiconductor devices, display devices, solar cells, etc.

[0038]

[0039] FIG. 2 is a schematic drawing showing a substrate processing device according to an embodiment of the present invention.

[0040] Referring to FIG. 2, a substrate processing device according to an embodiment of the present invention is a device for forming a thin film, for example, a metal oxide thin film, and includes a chamber (10), a substrate support unit (20) provided within the chamber (10) to support a substrate (S) provided within the chamber (10), a gas injection unit (30) provided within the chamber (10) to face the substrate support unit (20) and to inject a process gas toward the substrate support unit (20), and a gas supply unit (40) for supplying the gas to the gas injection unit (30). In addition, the substrate processing device may further include an RF power source (50) for applying power to generate plasma within the chamber (10) and a control unit (not shown) for controlling the RF power source (50). Here, a first gas supply path for supplying a first gas and a second gas supply path for supplying a second gas are formed separately in the gas injection unit (30).

[0041] The chamber (10) provides a predetermined reaction space and maintains it airtight. The chamber (10) may include a body (12) having a predetermined reaction space, including a flat surface of approximately circular or rectangular shape and a side wall extending upward from the flat surface, and a cover (14) positioned on the body (12) in an approximately circular or rectangular shape to maintain the reaction space airtight. However, the chamber (10) is not limited thereto and may be manufactured in various shapes corresponding to the shape of the substrate (S).

[0042] An exhaust port (not shown) may be formed in a predetermined area on the lower surface of the chamber (10), and an exhaust pipe (not shown) connected to the exhaust port may be provided on the outside of the chamber (10). In addition, the exhaust pipe may be connected to an exhaust device (not shown). A vacuum pump such as a turbo molecular pump may be used as the exhaust device. Therefore, the inside of the chamber (10) may be vacuum-sucked to a predetermined reduced pressure atmosphere, for example, a predetermined pressure of 0.1 mTorr or less, by the exhaust device. The exhaust pipe may be installed not only on the lower surface of the chamber (10), but also on the side surface of the chamber (10) below the substrate support member (20) described later. In addition, it goes without saying that a plurality of exhaust pipes and corresponding exhaust devices may be further installed in order to reduce the exhaust time.

[0043] Meanwhile, a substrate (S) provided into the chamber (10) for a thin film formation process may be mounted on the substrate support (20). Here, the substrate (S) may be a substrate that has already undergone a predetermined treatment before forming a metal oxide thin film. For example, the substrate (S) may be a substrate on which a gate electrode (110) has already been formed to form a gate insulating film (120) included in a transistor (100), and may be a substrate on which a first capacitor electrode (210) has already been formed to form a dielectric layer (220) included in a capacitor (200). The substrate support (20) may be equipped with, for example, an electrostatic chuck or the like to hold the substrate (S) by electrostatic force so that the substrate (S) may be mounted and supported, or the substrate (S) may be supported by vacuum adsorption or mechanical force.

[0044] The substrate support (20) may be provided in a shape corresponding to the shape of the substrate (S), for example, a circle or a square. The substrate support (20) may include a substrate support (22) on which the substrate (S) is mounted, and an elevator (24) disposed below the substrate support (22) to move the substrate support (22) up and down. Here, the substrate support (22) may be manufactured to be larger than the substrate (S), and the elevator (24) is provided to support at least one area of ​​the substrate support (22), for example, the center, and when the substrate (S) is mounted on the substrate support (22), the substrate support (22) may be moved closer to the gas injection unit (30). In addition, a heater (not shown) may be installed inside the substrate support (22). The heater generates heat to a predetermined temperature to heat the substrate support (22) and the substrate (S) mounted on the substrate support (22), thereby allowing a thin film to be uniformly deposited on the substrate (S).

[0045] The gas supply unit (40) may be installed to penetrate the cover (14) of the chamber (10), and may include a first gas supplier (42) and a second gas supplier (44) to provide a first gas and a second gas to the gas injection unit (30), respectively. Here, the first gas may be a raw material gas including a metal, and the second gas may be a reaction gas including oxygen. Conversely, the first gas may include a reaction gas, and the second gas may include a raw material gas, of course. Meanwhile, the first gas supplier (42) and the second gas supplier (44) do not necessarily provide one gas, and the first gas supplier (42) and the second gas supplier (44) may be configured to supply a plurality of gases simultaneously, or to supply a gas selected from among the plurality of gases, respectively. For example, the first gas supplier (42) can supply raw material gas and purge gas simultaneously, or the second gas supplier (44) can supply reaction gas and purge gas simultaneously.

[0046] The gas injection unit (30) is installed inside the chamber (10), for example, on the lower surface of the cover (14), and a first gas supply path for supplying a first gas by injecting it onto a substrate and a second gas supply path for supplying a second gas by injecting it onto the substrate are formed inside the gas injection unit (30). The first gas supply path and the second gas supply path are formed to be independent and separate from each other, so that the first gas and the second gas can be supplied onto the substrate separately without being mixed within the gas injection unit (30).

[0047] The gas injection unit (30) may include an upper frame (32) and a lower frame (34). Here, the upper frame (32) is detachably attached to the lower surface of the cover (14) and, at the same time, a portion of the upper surface, for example, a central portion of the upper surface, is spaced apart from the lower surface of the cover (14) by a predetermined distance. Accordingly, a first gas can be diffused from a first gas supply unit (42) in the space between the upper surface of the upper frame (32) and the lower surface of the cover (14). In addition, the lower frame (34) is installed at a predetermined distance from the lower surface of the upper frame (32). Accordingly, a second gas provided from a second gas supply unit (44) can be diffused in the space between the upper surface of the lower frame (34) and the lower surface of the upper frame (32). The upper frame (32) and the lower frame (34) may be formed as one piece by being connected along the outer surface to form a spaced space inside, and of course, may be formed as a structure in which the outer surface is sealed by a separate sealing member.

[0048] The first gas supply path may be formed so that the first gas provided from the first gas supply unit (42) is diffused in the space between the lower surface of the cover (14) and the upper frame (32) and is supplied into the chamber (10) through the upper frame (32) and the lower frame (34). In addition, the second gas supply path may be formed so that the second gas provided from the second gas supply unit (44) is diffused in the space between the lower surface of the upper frame (32) and the upper surface of the lower frame (34) and is supplied into the chamber (10) through the lower frame (34). The first gas supply path and the second gas supply path may not be connected to each other, whereby the first gas and the second gas may be separately supplied into the chamber (10) through the gas injection unit (30) from the gas supply unit (40).

[0049] A first plate, i.e., a first electrode (38), may be installed on the lower surface of the lower frame (34), and a second plate, i.e., a second electrode (36), may be installed at a predetermined interval on the lower side of the lower frame (24) and the outer side of the first electrode (28). At this time, the lower frame (34) and the second electrode (36) may be formed by being connected along the outer circumference, and of course, may be formed with a structure in which the outer circumference is sealed by a separate sealing member.

[0050] In this way, when the first electrode (38) and the second electrode (36) are installed, the first gas can be sprayed onto the substrate through the first electrode (38), and the second gas can be sprayed onto the substrate through the space between the first electrode (38) and the second electrode (36).

[0051] Either the lower frame (34) or the second electrode (36) may be supplied with RF power from the RF power source (50). That is, either the lower frame (34) or the second electrode (36) may be supplied with RF power from the RF power source (50). In FIG. 4, a structure in which the lower frame (34) is grounded and RF power is applied to the second electrode (36) is illustrated as an example. When the lower frame (34) is grounded, the first electrode (38) installed on the lower surface of the lower frame (34) is also grounded. Therefore, when the RF power (50) is applied to the second electrode (36), a first activation region, that is, a first plasma region (P1), may be formed between the gas injection unit (30) and the substrate support unit (20), and a second activation region, that is, a second plasma region (P2), may be formed between the first electrode (38) and the second electrode (36).

[0052]

[0053] FIG. 3 is a drawing showing how plasma is formed according to an embodiment of the present invention. In FIG. 3, the first electrode (38) and the substrate support (20) are grounded, and RF power (50) is applied to the second electrode (36), but the power application structure is not limited thereto.

[0054] As illustrated in FIG. 3, a first gas, for example, a raw material gas including a metal, may be supplied into the chamber (10) along an arrow indicated by a solid line, and a second gas, for example, a reaction gas including oxygen, may be supplied into the chamber (10) along an arrow indicated by a dotted line. The first gas may be supplied into the chamber (10) by penetrating the interior of the first electrode (38), and the second gas may be supplied into the chamber (10) through a space between the first electrode (38) and the second electrode (36). The first gas may be supplied into the chamber (10) by penetrating the first electrode (38).

[0055] When the first electrode (38) and the substrate support (20) are grounded and power is applied to the second electrode (36), a first activation region, i.e., a first plasma region (P1), is formed between the gas injection part (30) and the substrate support (20), and a second activation region, i.e., a second plasma region (P2), is formed between the first electrode (38) and the second electrode (36).

[0056] Accordingly, when the first gas is supplied by penetrating the first electrode (38), the first gas is activated in the first plasma region (P1) formed outside the gas injection unit (30). In addition, when the second gas is supplied through the space between the first electrode (38) and the second electrode (36), the second gas is activated in the region between the first electrode (38) and the second electrode (36) corresponding to the inside of the gas injection unit (30), that is, from the second plasma region (P2) to the first plasma region (P1). Therefore, the substrate processing apparatus according to an embodiment of the present invention can activate the first gas and the second gas in plasma regions of different sizes. In addition, since the first gas and the second gas are activated in plasma regions of different sizes, each gas can be distributed to an optimal supply path for depositing a thin film, and damage to the thin film caused by plasma can be prevented.

[0057]

[0058] Hereinafter, the thin film forming method of the present invention will be described in detail with reference to FIGS. 4 and 5. The thin film forming method according to an embodiment of the present invention may be a method of forming a thin film using the substrate processing apparatus described above, and therefore, any description overlapping with the above-described content with respect to the substrate processing apparatus will be omitted.

[0059] A method for forming a thin film according to an embodiment of the present invention is an atomic layer deposition process that sequentially performs a step of supplying a raw material gas (S100) and a step of supplying a reaction gas (S200), and forms a thin film on a substrate (S) provided in a reaction space, the method comprising a step of forming a dielectric layer including a metal by performing a step of supplying a hydrogen-containing gas (S300) after at least one of the steps of supplying the raw material gas (S100) and the step of supplying the reaction gas (S200). At this time, the step of supplying the hydrogen-containing gas (S300) includes a step of applying power to the reaction space.

[0060] In order to form a thin film on a substrate (S) using an atomic layer deposition process, a step of first preparing the substrate (S) may be performed. The step of preparing the substrate (S) includes bringing the substrate (S) into the reaction space of the chamber (10). The substrate (S) brought into the reaction space may be seated on a support (200). Here, the substrate (S) may include various semiconductor substrates. For example, the substrate (S) may be a semiconductor substrate including silicon (Si), and such a substrate (S) may be a substrate on which a predetermined treatment has already been performed before forming a dielectric thin film including a metal. For example, the substrate (S) may be a substrate on which a gate electrode (110) has already been formed to form a gate insulating film (120) included in a transistor (100), and may be a substrate on which a first capacitor electrode (210) has already been formed to form a dielectric layer (220) included in a capacitor (200). A substrate (S) like this is supported on a support (200), and the support (200) may be equipped with, for example, an electrostatic chuck to hold the substrate (S) by electrostatic force, or the substrate (S) may be supported by vacuum suction or mechanical force.

[0061] The step of forming a dielectric layer includes forming a dielectric thin film containing a metal, for example, a thin film containing a metal oxide, on a substrate (S) through an atomic layer deposition (ALD) process. At this time, the metal oxide may include at least one of aluminum oxide (Al2O3), zirconium oxide (ZrO2, Zr2O3), hafnium oxide (HfO2, Hf2O3), tantalum oxide (TaO2, Ta2O3), and titanium oxide (TiO2, Ti2O3) having a high dielectric constant (High-K). In addition, the dielectric layer may include a composite film formed by combining thin films containing such metal oxides.

[0062] Here, the step of forming a dielectric layer may include a step (S100) of supplying a raw material gas containing a metal through a first gas supply path onto a substrate (S) and a step (S200) of supplying a reaction gas containing oxygen through a second gas supply path different from the first gas supply path onto the substrate (S). At this time, at least one of the step (S100) of supplying the raw material gas and the step (S200) of supplying the reaction gas may include a step of applying RF power to a reaction space to form plasma of the raw material gas or the reaction gas.

[0063] The step of supplying a raw material gas (S100) supplies a raw material gas containing a metal onto a substrate (S) through a first gas supply path. For example, the step of supplying a raw material gas (S100) may supply a raw material gas containing at least one of aluminum (Al), zirconium (Zr), hafnium (Hf), tantalum (Ta), and titanium (Ti) onto the substrate (S) through the first gas supply path.

[0064] The step of supplying a reaction gas (S200) supplies a reaction gas containing oxygen through a second gas supply path onto a substrate (S) to which a raw material gas has been supplied. For example, the step of supplying a reaction gas (S200) may supply oxygen (O2) gas or ozone (O3) through the second gas supply path onto the substrate (S).

[0065] Here, the step of supplying the raw material gas (S100) may include a step of supplying a first purge gas after supplying the raw material gas, and the step of supplying the reaction gas (S200) may include a step of supplying a second purge gas after supplying the reaction gas. That is, the step of forming the dielectric layer may be performed by sequentially supplying the raw material gas, the first purge gas, the reaction gas, and the second purge gas onto the substrate (S). At this time, if the step of supplying a hydrogen-containing gas (S300) described below is performed after the step of supplying the raw material gas (S100), a step of applying RF power to the reaction space to activate the hydrogen-containing gas may be performed after supplying the first purge gas. In addition, if the step of supplying a hydrogen-containing gas (S300) is performed after the step of supplying the reaction gas (S200), a step of applying RF power to the reaction space to activate the hydrogen-containing gas may be performed after supplying the second purge gas.

[0066] Alternatively, the step of forming the dielectric layer may be performed by continuously supplying the first purge gas and the second purge gas. That is, the step of supplying the raw material gas (S100) includes the step of supplying the first purge gas through the first gas supply path onto the substrate (S), and the step of supplying the first purge gas may be continuously performed while forming the metal oxide thin film. In addition, the step of supplying the reaction gas (S200) includes the step of supplying the second purge gas through the second gas supply path onto the substrate (S), and the step of supplying the second purge gas may be continuously performed while forming the metal oxide thin film. In this case, the first purge gas and the second purge gas may be continuously supplied even during the step of supplying the hydrogen-containing gas (S300) described below. Here, the first purge gas and the second purge gas may include an inert gas such as nitrogen (N2) or argon (Ar).

[0067] The step of supplying a hydrogen-containing gas (S300) may be performed after at least one of the step of supplying a raw material gas (S100) and the step of supplying a reaction gas (S200). That is, the step of supplying a hydrogen-containing gas (S300) may be performed after the step of supplying a raw material gas (S100), after the step of supplying a reaction gas (S200), or after each of the step of supplying a raw material gas (S100) and the step of supplying a reaction gas (S200). At this time, the step of supplying a hydrogen-containing gas (S300) may include a step of applying RF power to a reaction space so that plasma of a hydrogen-containing gas is formed by supplying RF power to either one of the lower frame (34) and the second electrode (36).

[0068] To explain this in more detail, the step (S300) of supplying a hydrogen-containing gas may be performed before the step (S200) of supplying a reaction gas, for example, after the step (S100) of supplying a raw material gas, as illustrated in FIG. 4. That is, in the method for forming a thin film according to an embodiment of the present invention, the step (S100) of supplying a raw material gas, the step (S300) of supplying a hydrogen-containing gas, and the step (S200) of supplying a reaction gas may be performed sequentially. At this time, the hydrogen-containing gas may be hydrogen (H2) gas, and when the hydrogen-containing gas is supplied, RF power may be applied to the reaction space to activate the hydrogen-containing gas and form plasma.

[0069] In the step of supplying the raw material gas (S100), the supplied raw material gas contains carbon (C) as an impurity in addition to the metal component included as a main component. If such carbon (C) component remains in the dielectric thin film including the metal, it deteriorates the quality of the thin film and significantly reduces the performance of the semiconductor device in which the thin film is used. Therefore, in the method of forming a thin film according to an embodiment of the present invention, in order to reduce such impurities, after the step of supplying the raw material gas (S100) and before the step of supplying the reaction gas (S200), a hydrogen-containing gas is supplied onto the substrate (S) to form plasma. If the plasma including hydrogen is formed before the step of supplying the reaction gas (S200), the carbon (C) component included in the dielectric thin film including the metal can be removed by breaking the bonds of the remaining carbon (C).

[0070] Meanwhile, the step of forming a dielectric layer may include a step of supplying an oxygen-containing gas before or after supplying a hydrogen-containing gas, and the step of supplying the oxygen-containing gas may include a step of applying RF power to a reaction space so that plasma of the oxygen-containing gas is formed by supplying RF power to either one of the lower frame (34) and the second electrode (36). That is, the step of forming a dielectric layer (S300) may be performed by supplying the oxygen-containing gas before supplying the hydrogen-containing gas after the step of supplying the raw material gas (S100), by supplying the oxygen-containing gas before the step of supplying the reaction gas (S200), or by supplying the oxygen-containing gas before and after supplying the hydrogen-containing gas, respectively. At this time, the oxygen-containing gas may be oxygen (O2) gas, and when the oxygen-containing gas is supplied, RF power may be applied to the reaction space to activate the oxygen-containing gas and form plasma.

[0071] A dielectric layer containing a metal may be a metal oxide thin film having a high dielectric constant, and such a metal oxide thin film includes a large amount of oxygen vacancies within the thin film. Such oxygen vacancies act as defects that change electrical conductivity, and as described below, when the metal oxide thin film is used as a gate insulating film (120) of a transistor (100) or a dielectric layer (220) of a capacitor (200), its performance as an insulator is reduced, thereby significantly reducing the performance of a semiconductor device in which the metal oxide thin film is used. Accordingly, a method for forming a thin film according to an embodiment of the present invention performs a step of supplying an oxygen-containing gas before or after supplying a hydrogen-containing gas to remove such oxygen vacancies. When the oxygen-containing gas is supplied before or after supplying the hydrogen-containing gas to form an oxygen-containing plasma, the formation of oxygen vacancies in the metal oxide thin film can be suppressed. In addition, the stress of the thin film can be controlled, and the film quality can be improved.

[0072] Here, the step of supplying the oxygen-containing gas is performed after the step of supplying the hydrogen-containing gas (S300), and the step of forming the dielectric layer may include a step of further supplying the hydrogen-containing gas after the step of supplying the oxygen-containing gas. At this time, the step of further supplying the hydrogen-containing gas may include a step of applying RF power to the reaction space so that plasma of the hydrogen-containing gas is formed, and in this case, the bonds of carbon (C) remaining in the thin film are broken, so that the carbon (C) component included in the dielectric thin film including the metal can be more effectively removed.

[0073] In addition, when the step of forming a dielectric layer includes both the step of supplying a hydrogen-containing gas (S300) and the step of supplying an oxygen-containing gas, the step of supplying the hydrogen-containing gas (S300) may supply the hydrogen-containing gas for a different time than the time for supplying the oxygen-containing gas. For example, the step of supplying the hydrogen-containing gas (S300) may supply the hydrogen-containing gas for a longer time than the time for supplying the oxygen-containing gas. In this way, when the hydrogen-containing gas is supplied for a longer time than the oxygen-containing gas, the dielectric constant (k-value) of the thin film can be significantly increased while minimizing breakdown voltage loss compared to a case where the hydrogen-containing gas and the oxygen-containing gas are supplied for the same time.

[0074] Meanwhile, the step (S300) of supplying a hydrogen-containing gas may be performed after the step (S200) of supplying a reaction gas, for example, as illustrated in FIG. 5. That is, in the method for forming a thin film according to an embodiment of the present invention, the step (S100) of supplying a raw material gas, the step (S200) of supplying a reaction gas, and the step (S300) of supplying a hydrogen-containing gas may be sequentially performed. At this time, the hydrogen-containing gas may be hydrogen (H2) gas, and as described above, when the hydrogen-containing gas is supplied, the hydrogen-containing gas may be activated by applying RF power to the reaction space to form plasma. In addition, even when the step (S300) of supplying a hydrogen-containing gas is performed after the step (S200) of supplying a reaction gas, the plasma may be formed by supplying an oxygen-containing gas, for example, oxygen (O2) gas, before or after supplying the hydrogen-containing gas, as described above, and therefore, a duplicate description thereof will be omitted.

[0075] The step (S300) of supplying a hydrogen-containing gas may be performed before, after, or both before and after the step (S200) of supplying a reaction gas as described above. Here, the step (S100) of supplying a raw material gas, the step (S200) of supplying a reaction gas, and the step (S300) of supplying a hydrogen-containing gas, which may be performed before, after, or both before and after the step (S200) of supplying a reaction gas, may form a process cycle of an atomic layer deposition process, and such a process cycle may be repeated multiple times until a thin film having a desired thickness is formed.

[0076] In addition, the thin film forming method according to an embodiment of the present invention may form a thin film by sequentially performing different first process cycles and second process cycles. That is, the thin film forming method according to an embodiment of the present invention may include a step of forming a dielectric layer including a metal by performing a step of supplying a hydrogen-containing gas (S300) after at least one of a step of supplying a raw material gas (S100) and a step of supplying a reaction gas (S200), and a step of forming a dielectric layer including a metal by performing a step of supplying an oxygen-containing gas after at least one of a step of supplying a raw material gas (S100) and a step of supplying a reaction gas (S200). At this time, the step of supplying the oxygen-containing gas may include a step of applying RF power to a reaction space to form plasma, similar to the step of supplying the hydrogen-containing gas. In addition, the first process cycle for forming a dielectric layer including a metal by performing the step (S300) of supplying a hydrogen-containing gas may be performed multiple times, and the second process cycle for forming a dielectric layer including a metal by performing the step of supplying an oxygen-containing gas may be performed at least once. In addition, the first process cycle and the second process cycle may be performed sequentially, or a third process cycle different from the first process cycle and the second process cycle may be performed between the first process cycle and the second process cycle. For example, in the method for forming a thin film according to an embodiment of the present invention, after performing a plurality of first process cycles, a third process cycle for performing the step (S100) of supplying a raw material gas without supplying a hydrogen-containing gas or an oxygen-containing gas and the step (S200) of supplying a reaction gas may be performed, and then the second process cycle may be performed once or multiple times to form a thin film.

[0077] Here, the first process cycle for forming a dielectric layer including a metal by performing the step (S300) of supplying a hydrogen-containing gas can be performed 5 times or less. If the first process cycle is repeated more than this, current leakage and breakdown voltage loss may occur, so the first process cycle can be performed 5 times or less, and in this case, the dielectric constant of the thin film can be significantly increased while minimizing the breakdown voltage loss.

[0078] Meanwhile, the hydrogen-containing gas or oxygen-containing gas described above may be supplied through either the first gas supply path or the second gas supply path of the gas injection unit (30), in which case the hydrogen-containing gas or oxygen-containing gas may be activated inside the gas injection unit (30). For example, when the hydrogen-containing gas is supplied by penetrating the first electrode (38), the hydrogen-containing gas is activated in the first plasma region (P1) formed outside the gas injection unit (30). In addition, when the hydrogen-containing gas is supplied through the space between the first electrode (38) and the second electrode (36), the hydrogen-containing gas may be activated in the region between the first electrode (38) and the second electrode (36) corresponding to the inside of the gas injection unit (30), that is, from the second plasma region (P2) to the first plasma region (P1). In this way, in an embodiment of the present invention, a hydrogen-containing gas or an oxygen-containing gas can be distributed through an optimal supply path, and in this case, damage to a thin film due to the formation of plasma can be prevented.

[0079]

[0080] FIG. 6 is a schematic diagram showing a transistor according to an embodiment of the present invention.

[0081] The above-described thin film forming method can be used to form a gate insulating film (120) of a transistor (100) according to an embodiment of the present invention. At this time, the transistor (100) according to an embodiment of the present invention can include a gate electrode (110), an active layer (130) spaced apart from the gate electrode (110), a gate insulating film (120) disposed between the gate electrode (110) and the active layer (130), and source and drain electrodes (140a, 140b) disposed to be in contact with the active layer (130). Here, the transistor (100) can include a bottom gate type transistor in which the gate electrode (110) is disposed on the lower side of the gate insulating film (120), as illustrated in FIG. 6. Although not shown, it is to be understood that the transistor (100) may include a top gate type transistor in which the gate electrode (110) is positioned on the upper side of the gate insulating film (120).

[0082] Here, the gate electrode (110) may include a metal material. For example, the gate electrode (110) may include titanium nitride (TiN). That is, the transistor (100) according to an embodiment of the present invention may include a MOS (Metal-Oxide-Semiconductor) transistor in which a gate insulating layer (120) formed of a dielectric layer including a metal is disposed between a gate electrode (110) including a metal material and an active layer (130) including a semiconductor material. As such, in the embodiment of the present invention, when forming the gate insulating film (120) of the MOS transistor, a plasma treatment is performed by supplying a hydrogen-containing gas or supplying a hydrogen-containing gas and an oxygen-containing gas during the formation of the thin film, thereby minimizing the content of impurities and improving the film quality, and at the same time, implementing a MOS transistor having low power consumption required for control and a fast switching speed.

[0083]

[0084] FIG. 7 is a schematic diagram showing a capacitor according to an embodiment of the present invention.

[0085] The above-described thin film forming method can be used to form a dielectric layer (220) of a capacitor (200) according to an embodiment of the present invention. At this time, the capacitor (200) according to an embodiment of the present invention can include a first capacitor electrode (210), a second capacitor electrode (230) spaced apart from the first capacitor electrode (210), and a dielectric layer (220) disposed between the first capacitor electrode (210) and the second capacitor electrode (230).

[0086] Here, the capacitor electrodes (210, 230) may include a metal material. For example, the capacitor electrodes (210, 230) may include titanium nitride (TiN). That is, the capacitor (200) according to an embodiment of the present invention may include a MIM (Metal-Insulator-Metal) capacitor in which a dielectric layer (220) including a metal is disposed between a first capacitor electrode (210) including a metal material and a second capacitor electrode (230) including a metal material, as illustrated in FIG. 7. As such, in the embodiment of the present invention, when forming the dielectric layer (220) of the MIM capacitor, a plasma treatment is performed by supplying a hydrogen-containing gas or a hydrogen-containing gas and an oxygen-containing gas during the formation of a thin film, thereby minimizing the content of impurities and improving the film quality, and at the same time, implementing an MIM capacitor with a simplified manufacturing process.

[0087]

[0088] While the preferred embodiments of the present invention have been described and illustrated using specific terms above, such terms are solely for the purpose of clearly describing the present invention, and it is to be understood that various modifications and variations may be made to the embodiments and terms described herein without departing from the spirit and scope of the appended claims. Such modified embodiments should not be construed individually from the spirit and scope of the present invention, but should be considered to fall within the scope of the claims.

Claims

1. A method for forming a thin film on a substrate provided in a reaction space by sequentially performing the step of supplying a raw material gas and the step of supplying a reaction gas through an atomic layer deposition process, A step of forming a dielectric layer including a metal by performing a step of supplying a hydrogen-containing gas after at least one of the steps of supplying the raw material gas and the step of supplying the reaction gas; A method for forming a thin film, wherein the step of supplying the hydrogen-containing gas includes a step of applying power to the reaction space.

2. In claim 1, The forming step of forming a dielectric layer including a metal by performing the step of supplying the hydrogen-containing gas includes the step of supplying an oxygen-containing gas before or after supplying the hydrogen-containing gas, A method for forming a thin film, wherein the step of supplying the oxygen-containing gas includes a step of applying power to the reaction space.

3. In claim 2, The step of supplying the oxygen-containing gas is performed after the step of supplying the hydrogen-containing gas, A step of further supplying hydrogen-containing gas after the step of supplying the oxygen-containing gas; A method for forming a thin film, wherein the step of further supplying the hydrogen-containing gas comprises a step of applying power to the reaction space.

4. In claim 2, The step of supplying the above hydrogen-containing gas is: A thin film forming method wherein the hydrogen-containing gas is supplied for a time different from the time at which the oxygen-containing gas is supplied.

5. In claim 4, The step of supplying the above hydrogen-containing gas is: A thin film forming method wherein the hydrogen-containing gas is supplied for a longer period of time than the time for supplying the oxygen-containing gas.

6. In claim 1, The step of supplying the above raw material gas includes the step of supplying a purge gas after supplying the above raw material gas, The step of supplying the above reaction gas includes the step of supplying a purge gas after supplying the above reaction gas, A method for forming a thin film, wherein the step of applying power to the above reaction space is performed after supplying the purge gas.

7. In claim 1, After the forming step of forming a dielectric layer including a metal by performing the step of supplying the hydrogen-containing gas, A step of forming a dielectric layer including a metal by performing a step of supplying an oxygen-containing gas after at least one of the steps of supplying the raw material gas and the step of supplying the reaction gas; A method for forming a thin film, wherein the step of supplying the oxygen-containing gas includes a step of applying power to the reaction space.

8. In claim 7, A method for forming a thin film, wherein the forming step of forming a dielectric layer including a metal by performing the step of supplying the hydrogen-containing gas is performed repeatedly multiple times.

9. In claim 1, A method for forming a thin film, wherein at least one of the steps of supplying the raw material gas and the step of supplying the reaction gas includes a step of applying power to the reaction space.

10. In claim 1, The step of supplying the above hydrogen-containing gas is: A thin film formation method performed after the step of supplying the above raw material gas and after the step of supplying the above reaction gas.

11. Gate electrode; An active layer spaced apart from the gate electrode; A gate insulating film disposed between the gate electrode and the active layer; and source and drain electrodes arranged to be in contact with the active layer; A transistor wherein the gate insulating film comprises a dielectric layer including a metal formed by any one of the methods of claims 1 to 10.

12. First capacitor electrode; a second capacitor electrode spaced apart from the first capacitor electrode; and A dielectric layer disposed between the first capacitor electrode and the second capacitor electrode; A capacitor comprising a dielectric layer including a metal formed by any one of the methods of claims 1 to 10.

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