Ferroelectric capacitor and method for manufacturing the same

Abstract

The present invention relates to a ferroelectric capacitor including a first electrode including titanium nitride (TiN), a ferroelectric layer formed on the first electrode and including hafnium (Hf) oxide or hafnium zirconium oxide (HZO), and an interfacial layer disposed between the ferroelectric layer and the first electrode, and a method for manufacturing the ferroelectric capacitor.

Description

[Technical Field]

[0001] The present invention relates to a ferroelectric capacitor using a substance having ferroelectric properties and a method for manufacturing the ferroelectric capacitor. [Background technology]

[0002] Generally, a predetermined thin film layer, thin film circuit pattern, or optical pattern must be formed on a substrate to manufacture semiconductor devices, display devices, solar cells, etc. To achieve this, substrate processing processes are performed, such as a deposition process to deposit a thin film of a specific material on the substrate, a photo process to selectively expose the thin film using a photosensitive material, and an etching process to remove the thin film from the selectively exposed portions to form a pattern.

[0003] Through this process, a ferroelectric capacitor can be manufactured using ferroelectrics, which are materials with ferroelectric properties that maintain spontaneous polarization by aligning their internal electric dipole moments even without the application of an external electric field.

[0004] On the other hand, in ferroelectric capacitors using ferroelectrics, there is a demand for the development of a technology that can improve the film quality of the ferroelectric layer formed using the ferroelectric. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been devised to solve the above-mentioned problems, and aims to provide a ferroelectric capacitor and a method for manufacturing a ferroelectric capacitor that can improve the film quality of the ferroelectric layer. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention can include the following configurations.

[0007] A ferroelectric capacitor according to the present invention may include a first electrode including titanium nitride (TiN), a ferroelectric layer formed on the first electrode and including hafnium (Hf) oxide or hafnium zirconium oxide (HZO), and an interfacial layer disposed between the ferroelectric layer and the first electrode.

[0008] In the ferroelectric capacitor according to the present invention, the interfacial layer includes titanium oxide and can be formed by treating the first electrode with ozone (O3) or oxygen (O2).

[0009] In the ferroelectric capacitor according to the present invention, the interfacial layer may include titanium oxynitride (TiON).

[0010] A method for manufacturing a ferroelectric capacitor according to the present invention may include the steps of: preparing a substrate on which a first electrode containing titanium nitride (TiN) is formed; treating the first electrode with ozone (O3) or oxygen (O2) to form an interfacial layer containing titanium oxide on the first electrode; and forming a ferroelectric layer containing hafnium (Hf) oxide or hafnium zirconium oxide (HZO) on the interfacial layer.

[0011] A method for manufacturing a ferroelectric capacitor according to the present invention may include the steps of: preparing a substrate on which a first electrode containing titanium nitride (TiN) is formed; forming an interfacial layer containing titanium oxynitride (TiON) on the first electrode; and forming a ferroelectric layer containing hafnium (Hf) oxide or hafnium zirconium oxide (HZO) on the interfacial layer. [Effects of the Invention]

[0012] According to the present invention, the following effects can be obtained.

[0013] The present invention can suppress the formation of oxygen vacancies during the formation of the ferroelectric layer by using an interface layer disposed between the first electrode and the ferroelectric layer, thereby further enhancing the ferroelectricity of the ferroelectric layer and increasing the remanent polarization of the ferroelectric layer, thereby enabling the device to be driven at a lower voltage.

[0014] The present invention can be embodied to form a ferroelectric layer containing hafnium zirconium oxide (HZO) by simultaneously supplying hafnium and zirconium. Accordingly, the present invention can improve the film quality of the ferroelectric layer by using hafnium zirconium oxide. Furthermore, since the present invention forms a ferroelectric layer by simultaneously supplying hafnium and zirconium, it can contribute to shortening the process time for forming the ferroelectric layer. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic diagram illustrating an example of a substrate processing apparatus for manufacturing a ferroelectric capacitor according to the present invention; [Figure 2] 1 is a schematic side cross-sectional view of an injection unit that injects gas in an example of a substrate processing apparatus for manufacturing a ferroelectric capacitor according to the present invention. [Figure 3] 1 is a schematic side cross-sectional view of an injection unit that injects gas in an example of a substrate processing apparatus for manufacturing a ferroelectric capacitor according to the present invention. [Figure 4] 1 is a schematic cross-sectional side view of a ferroelectric capacitor according to the present invention; [Figure 5] 2A to 2C are schematic cross-sectional side views illustrating a manufacturing process of a ferroelectric capacitor according to the present invention. [Figure 6] 2A to 2C are schematic cross-sectional side views illustrating a manufacturing process of a ferroelectric capacitor according to the present invention. [Figure 7] 2A to 2C are schematic cross-sectional side views illustrating a manufacturing process of a ferroelectric capacitor according to the present invention. [Figure 8]1 is a schematic flow chart of a method for manufacturing a ferroelectric capacitor according to the present invention. [Figure 9] 1 is a schematic flow chart of a method for manufacturing a ferroelectric capacitor according to the present invention. [Figure 10] 1 is a schematic flow chart of a method for manufacturing a ferroelectric capacitor according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the ferroelectric capacitor according to the present invention will be described in detail with reference to the accompanying drawings. In describing the embodiments of the present invention, when a structure is described as being formed "on" or "under" another structure, this description should be interpreted as including not only when these structures are in contact with each other, but also when a third structure is interposed between these structures.

[0017] 1 to 4, the ferroelectric capacitor 200 according to the present invention can be manufactured by a processing process on a substrate 210. The substrate 210 can be a silicon substrate, a glass substrate, a metal substrate, etc. The ferroelectric capacitor 200 according to the present invention can be manufactured using a ferroelectric material having ferroelectricity.

[0018] The ferroelectric capacitor 200 according to the present invention can be manufactured by a processing process using the substrate processing apparatus 1. Before describing an embodiment of the ferroelectric capacitor 200 according to the present invention, an example of the substrate processing apparatus 1 will be described in detail below.

[0019] The substrate processing apparatus 1 may include a chamber 2 , a substrate support 3 , and an ejector 4 .

[0020] 1 to 3, the chamber 2 provides a processing space 100. In the processing space 100, a processing process can be performed on the substrate 210. The processing space 100 can be disposed inside the chamber 2. The chamber 2 can be coupled with an exhaust port (not shown) for exhausting gas from the processing space 100. The substrate support unit 3 and the spray unit 4 can be disposed inside the chamber 2.

[0021] The substrate support 3 supports the substrate 210. The substrate support 3 can support one substrate 210 or multiple substrates 210. When multiple substrates 210 are supported on the substrate support 3, processing steps are performed on the multiple substrates 210 at once, and a process for manufacturing a ferroelectric capacitor 200 can be performed on each of the substrates 210. The substrate support 3 can be coupled to the chamber 2. The substrate support 3 can be disposed inside the chamber 2.

[0022] The injector 4 injects gas toward the substrate support 3. The injector 4 may be connected to a supply unit (not shown). In this case, the injector 4 may inject the gas supplied from the supply unit toward the substrate support 3. The injector 4 may be disposed inside the chamber 2. The injector 4 may be disposed to face the substrate support 3. The injector 4 may be disposed above the substrate support 3. The processing space 100 may be disposed between the injector 4 and the substrate support 3. The injector 4 may be connected to a lead (not shown). The lead may be connected to the chamber 2 to cover the top of the chamber 2.

[0023] The injection unit 4 may include a first gas passage 4a and a second gas passage 4b.

[0024] The first gas passage 4a is for injecting a first gas. One side of the first gas passage 4a may be connected to a supply unit via a pipe, a hose, etc. The other side of the first gas passage 4a may be connected to the processing space 100. Thus, the first gas supplied from the supply unit may flow along the first gas passage 4a and then be injected into the processing space 100 through the first gas passage 4a. The first gas passage 4a functions as a passage for the first gas to flow and also as an injection port for injecting the first gas into the processing space 100.

[0025] The second gas passage 4b ​​is for injecting a second gas. The second gas and the first gas may be different gases. For example, when the first gas is a source gas, the second gas may be a reactant gas. One side of the second gas passage 4b ​​may be connected to the supply unit through a pipe, a hose, or the like. The other side of the second gas passage 4b ​​may be connected to the processing space 100. Therefore, the second gas supplied from the supply unit may flow along the second gas passage 4b ​​and then be injected into the processing space 100 through the second gas passage 4b. The second gas passage 4b ​​may function as a passage for the second gas to flow and as an injection port for injecting the second gas into the processing space 100.

[0026] The second gas passage 4b ​​and the first gas passage 4a may be arranged to be spatially separated from each other. Thus, the second gas supplied from the supply unit to the second gas passage 4b ​​may be sprayed into the processing space 100 without passing through the first gas passage 4a. The first gas supplied from the supply unit to the first gas passage 4a may be sprayed into the processing space 100 without passing through the second gas passage 4b. The second gas passage 4b ​​and the first gas passage 4a may be arranged to spray gases toward different portions of the processing space 100.

[0027] For example, as shown in FIG. 2, the injection unit 4 may include a first plate 41 and a second plate 42 .

[0028] The first plate 41 is disposed above the second plate 42. The first plate 41 and the second plate 42 may be spaced apart from each other. The first plate 41 may have a plurality of first gas holes 411 formed therein. The first gas holes 411 may function as passages for the first gas to flow. The first gas holes 411 may belong to the first gas flow path 4a. The first plate 41 may have a plurality of second gas holes 412 formed therein. The second gas holes 412 may function as passages for the second gas to flow. The second gas holes 412 may belong to the second gas flow path 4b. The first plate 41 may have a plurality of protruding members 413 attached thereto. The protruding members 413 may protrude from the lower surface of the first plate 41 toward the second plate 42. Each of the first gas holes 411 may be formed to penetrate the first plate 41 and the protruding members 413.

[0029] A plurality of openings 421 may be formed in the second plate 42. The openings 421 may be formed through the second plate 42. The openings 421 may be disposed at positions corresponding to the protruding members 413, respectively. Therefore, as shown in FIG. 2, the protruding members 413 may be formed to a length that allows them to be inserted into the respective openings 421. Although not shown, the protruding members 413 may also be formed to a length that allows them to be disposed above the respective openings 421. The protruding members 413 may also be formed to a length that protrudes downward from the second plate 42. The second gas holes 412 may be disposed to inject gas toward the upper surface of the second plate 42. Although not shown, the lower surface of the first plate 41 may be formed flat without the protruding members 413.

[0030] For example, as shown in FIG. 3, the second plate 42 may have a plurality of first openings 422 and a plurality of second openings 423 formed therein.

[0031] The first openings 422 may be formed through the second plate 42. The first openings 422 may be connected to the first gas holes 411, respectively. In this case, the protruding members 413 may be disposed to contact the upper surface of the second plate 42. The first gas may be injected into the processing space 100 through the first gas holes 411 and the first openings 422. The first gas holes 411 and the first openings 422 may belong to the first gas passage 4a.

[0032] The second opening 423 may be formed through the second plate 42. The second opening 423 may be connected to a buffer space 43 disposed between the first plate 41 and the second plate 42. The second gas may be injected into the processing space 100 through the second gas holes 412, the buffer space 43, and the second opening 423. The second gas holes 412, the buffer space 43, and the second opening 423 may belong to the second gas passage 4b.

[0033] Although not shown, if the lower surface of the first plate 41 is formed flat without the protruding members 413, the first gas and the second gas may be supplied to the space between the first plate 41 and the second plate 42 through the first gas hole 411 and the second gas hole 412, respectively, and then injected into the processing space 100 through the first opening 422 and the second opening 423. In this case, if the first gas is supplied through the first gas hole 411 and the second gas is supplied through the second gas hole 412 simultaneously, the first gas and the second gas may be mixed in the space between the first plate 41 and the second plate 42 and then injected into the processing space 100 through the first opening 422 and the second opening 423.

[0034] Meanwhile, the first openings 422 may be disposed vertically below the first gas holes 411. In this case, the first openings 422 and the first gas holes 411 may be disposed on the same vertical line. Although not shown, the first openings 422 and the first gas holes 411 may be disposed at positions offset from each other. In this case, the first openings 422 and the first gas holes 411 may be disposed at positions where they do not overlap each other, or may be disposed at positions where they only partially overlap each other.

[0035] Meanwhile, the second openings 423 may be disposed vertically below the second gas holes 412. In this case, the second openings 423 and the second gas holes 412 may be disposed on the same vertical line. Although not shown, the second openings 423 and the second gas holes 412 may be disposed at positions offset from each other. In this case, the second openings 423 and the second gas holes 412 may be disposed at positions where they do not overlap each other, or may be disposed at positions where they only partially overlap each other.

[0036] Meanwhile, the injection unit 4 may form plasma using the second plate 42 and the first plate 41. In this case, a plasma power source such as RF power may be applied to the first plate 41 and the second plate 42 may be grounded, or the first plate 41 may be grounded and the plasma power source may be applied to the second plate 42.

[0037] The ferroelectric capacitor 200 according to the present invention can be manufactured by the processing steps using the substrate processing apparatus 1. The ferroelectric capacitor 200 according to the present invention can include a first electrode 220 and a ferroelectric layer 230.

[0038] 1 to 4, the first electrode 220 is formed on the substrate 210. The first electrode 220 may include titanium nitride (TiN). The first electrode 220 may be disposed between the substrate 210 and the ferroelectric layer 230. In the ferroelectric capacitor 200 according to the present invention, the first electrode 220 may function as a lower electrode. The first electrode 220 may be manufactured using the substrate processing apparatus 1. In this case, a source gas including titanium may be injected through the first gas passage 4a. A reactant gas including nitrogen may be injected through the second gas passage 4b.

[0039] 1 to 4, the ferroelectric layer 230 is formed on the first electrode 220. The ferroelectric layer 230 may be manufactured using a ferroelectric material having ferroelectric properties. The ferroelectric layer 230 may include hafnium (Hf) oxide. In this case, a source gas including hafnium may be injected through the first gas passage 4a. A reactant gas including oxygen may be injected through the second gas passage 4b. As a result, the ferroelectric layer 230 may be formed by atomic layer deposition (ALD).

[0040] The ferroelectric layer 230 may also contain hafnium and zirconium. When the ferroelectric layer 230 contains hafnium and zirconium, the ferroelectric layer 230 may be formed to contain hafnium zirconium oxide (HZO). Therefore, the ferroelectric capacitor 200 according to the present invention can improve the film quality of the ferroelectric layer 230 by using hafnium zirconium oxide. The ferroelectric layer 230 can be formed by simultaneously supplying hafnium and zirconium (Zr) to the first electrode 220. In this case, compared to a comparative example in which the ferroelectric layer 230 is formed by sequentially supplying hafnium and zirconium, the ferroelectric capacitor 200 according to the present invention forms the ferroelectric layer 230 by simultaneously supplying hafnium and zirconium, thereby contributing to shortening the process time for forming the ferroelectric layer 230. In this case, a source gas containing a mixture of hafnium and zirconium can be injected through the first gas passage 4a. That is, hafnium and zirconium can be supplied in a co-flow manner. A reactant gas containing oxygen can be injected through the second gas passage 4b. As a result, the ferroelectric layer 230 containing hafnium zirconium oxide can be formed by atomic layer deposition (ALD).

[0041] The ferroelectric layer 230 may be formed on the first electrode 220 and then annealed using a nitrogen-containing gas. By crystallizing the ferroelectric layer 230 through such a heat treatment, the ferroelectric capacitor 200 according to the present invention may be implemented to include a ferroelectric layer 230 with improved film quality. When the ferroelectric layer 230 includes hafnium zirconium oxide, the hafnium zirconium oxide may be crystallized through the heat treatment. Meanwhile, the ferroelectric layer 230 may be implemented by performing a PMA (Post Metallization Annealing) process for 10 to 20 seconds in a nitrogen-containing gas atmosphere at 500 to 550°C.

[0042] Referring to FIGS. 1 to 7, the ferroelectric capacitor 200 according to the present invention may further include an interface layer 240.

[0043] The interface layer 240 is disposed between the ferroelectric layer 230 and the first electrode 220. The interface layer 240 may be formed on the first electrode 220. In this case, the ferroelectric layer 230 may be formed on the interface layer 240.

[0044] The interface layer 240 may include titanium oxide. Accordingly, the interface layer 240 can suppress the formation of oxygen vacancies during the formation of the ferroelectric layer 230 by utilizing the oxygen scavenging effect of titanium oxide. Therefore, the interface layer 240 can further enhance the ferroelectric properties of the ferroelectric layer 230. Furthermore, the ferroelectric capacitor 200 according to the present invention can be implemented to be driven at a lower voltage by increasing the remanent polarization of the ferroelectric layer 230. The interface layer 240 can suppress the formation of oxygen vacancies during a heat treatment process of the ferroelectric layer 230 or during the initial stage of growth of the ferroelectric layer 230 through atomic layer deposition (ALD).

[0045] The interface layer 240 may be implemented by treating the first electrode 220 with ozone (O3). In this case, the interface layer 240 may include titanium dioxide (TiO2). By treating the first electrode 220 containing titanium nitride with ozone, a TiNxOy and titanium dioxide thin film is formed on the first electrode 220. However, the high ozone concentration resulting from the ozone treatment can result in the formation of a low concentration of oxygen vacancies. This prevents the high concentration of oxygen vacancies from impeding the stabilization of the ferroelectric during the formation of the ferroelectric layer 230, thereby weakening the ferroelectricity of the ferroelectric layer 230. Therefore, the low concentration of oxygen vacancies resulting from the ozone treatment can strengthen the ferroelectricity of the ferroelectric layer 230 by inducing stable initial growth of the ferroelectric. In this case, compared to the comparative example in which the interface layer 240 including titanium dioxide (TiO2) is formed on the first electrode 220 by deposition, the embodiment treats the first electrode 220 with ozone, thereby achieving a low concentration of oxygen vacancies due to a high ozone concentration at the initial stage of growth, thereby further enhancing the ferroelectricity through more stable growth of the ferroelectric. The process of treating the first electrode 220 with ozone can be performed by the injection unit 4 of the substrate processing apparatus 1 injecting ozone and forming plasma.

[0046] The interface layer 240 can also be implemented by treating the first electrode 220 with oxygen (O2). In this case, the interface layer 240 can include titanium dioxide (TiO2). By treating the first electrode 220 containing titanium nitride with oxygen, a TiNxOy and titanium dioxide thin film is formed on the first electrode 220. However, the high oxygen concentration resulting from the oxygen treatment can result in the formation of a low concentration of oxygen vacancies. This prevents the high concentration of oxygen vacancies from interfering with the stabilization of the ferroelectric during the formation of the ferroelectric layer 230, thereby weakening the ferroelectricity of the ferroelectric layer 230. Therefore, the low concentration of oxygen vacancies resulting from the oxygen treatment can strengthen the ferroelectricity of the ferroelectric layer 230 by inducing stable initial growth of the ferroelectric. In this case, compared to the comparative example in which the interface layer 240 including titanium dioxide (TiO2) is formed on the first electrode 220 by deposition, the embodiment treats the first electrode 220 with oxygen to achieve a high oxygen concentration at the initial stage of growth and a low concentration of oxygen vacancies, thereby further enhancing the ferroelectricity through more stable growth of the ferroelectric. The process of treating the first electrode 220 with oxygen can be performed by the injection unit 4 of the substrate processing apparatus 1 injecting oxygen and forming plasma.

[0047] The interface layer 240 may be treated with oxygen plasma (O2 plasma). As a result, impurities may be removed from the interface layer 240 of the ferroelectric capacitor 200 according to the present invention, thereby improving the film quality of the interface layer 240. Furthermore, since the ferroelectric layer 230 is formed on the interface layer 240 after the interface layer 240 is treated with oxygen plasma, the film quality of the ferroelectric layer 230 of the ferroelectric capacitor 200 according to the present invention may be further improved. In this case, the oxygen plasma may be formed by the spray unit 4.

[0048] The interface layer 240 may be formed to include titanium oxynitride (TiON). Accordingly, the interface layer 240 can suppress the formation of oxygen vacancies during the formation of the ferroelectric layer 230 by utilizing the oxygen-scavenging effect of titanium oxynitride. Therefore, the interface layer 240 can further enhance the ferroelectric properties of the ferroelectric layer 230. Furthermore, the ferroelectric capacitor 200 according to the present invention can be driven at a lower voltage by increasing the remanent polarization of the ferroelectric layer 230. The interface layer 240 can suppress the formation of oxygen vacancies during a heat treatment process of the ferroelectric layer 230 or during the initial stage of growth of the ferroelectric layer 230 through atomic layer deposition (ALD).

[0049] When the interface layer 240 is formed to include titanium oxynitride, the interface layer 240 can be formed by sequentially injecting a source gas containing titanium, a first reactant gas containing oxygen, and a second reactant gas containing nitrogen. In this case, the source gas containing titanium can be injected through the first gas passage 4a, and the first reactant gas containing oxygen and the second reactant gas containing nitrogen can be injected sequentially through the second gas passage 4b. Alternatively, the source gas containing titanium can be injected through the first gas passage 4a, the first reactant gas containing oxygen can be injected through the second gas passage 4b, and the second reactant gas containing nitrogen can be injected through a third gas passage (not shown).

[0050] Referring to FIGS. 1 to 7, the ferroelectric capacitor 200 may include a second electrode 250.

[0051] The second electrode 250 may be formed on the ferroelectric layer 230. The second electrode 250 may include titanium nitride. In the ferroelectric capacitor 200 according to the present invention, the second electrode 250 may function as an upper electrode. The second electrode 250 and the first electrode 220 may be formed to include different materials.

[0052] Hereinafter, an embodiment of a method for manufacturing a ferroelectric capacitor according to the present invention will be described in detail with reference to the accompanying drawings.

[0053] 1 to 8, a method for manufacturing a ferroelectric capacitor according to the present invention may be used to manufacture the above-described ferroelectric capacitor 200 according to the present invention. The method for manufacturing a ferroelectric capacitor according to the present invention may include the following steps.

[0054] First, a substrate having a first electrode 220 formed thereon is prepared (S10). This step (S10) can be performed by preparing a substrate having a first electrode 220 containing titanium nitride formed thereon. The step (S10) of preparing a substrate can also be performed by placing the substrate 210 having a first electrode 220 containing titanium nitride formed thereon on the substrate support 3 of the substrate processing apparatus 1.

[0055] Next, a ferroelectric layer 230 is formed on the first electrode 220 (S20). This step (S20) can be performed by forming the ferroelectric layer 230 on the first electrode 220 using a ferroelectric material having ferroelectric properties. The step (S20) of forming the ferroelectric layer can be performed by forming the ferroelectric layer 230 containing hafnium oxide. When the step (S20) of forming the ferroelectric layer is performed using the substrate processing apparatus 1, the ferroelectric layer 230 can be formed by injecting a source gas containing hafnium through the first gas passage 4a and then injecting a reactant gas containing oxygen through the second gas passage 4b. In this case, the ferroelectric layer 230 can be formed by atomic layer deposition (ALD).

[0056] The step of forming a ferroelectric layer (S20) may also form a ferroelectric layer 230 further containing zirconium. The step of forming a ferroelectric layer (S20) may also be performed by forming the ferroelectric layer 230 containing hafnium zirconium oxide on the first electrode 220. As a result, the method for manufacturing a ferroelectric capacitor according to the present invention can improve the film quality of the ferroelectric layer 230 by using hafnium zirconium oxide. The step of forming a ferroelectric layer (S20) may also form the ferroelectric layer 230 containing hafnium zirconium oxide on the first electrode 220 by simultaneously supplying hafnium and zirconium to the first electrode 220. In this case, compared to a comparative example in which the ferroelectric layer 230 is formed by sequentially supplying hafnium and zirconium, the method for manufacturing a ferroelectric capacitor according to the present invention can shorten the process time for forming the ferroelectric layer 230 by simultaneously supplying hafnium and zirconium. Therefore, the method for manufacturing a ferroelectric capacitor according to the present invention can contribute to increasing the production yield of the ferroelectric capacitor 200. When the step (S20) of forming the ferroelectric layer is performed using the substrate processing apparatus 1, a source gas containing a mixture of hafnium and zirconium can be injected through the first gas passage 4a. That is, hafnium and zirconium can be supplied in a co-flow manner. Meanwhile, after injecting the source gas containing a mixture of hafnium and zirconium through the first gas passage 4a, a reactant gas containing oxygen can be injected through the second gas passage 4b. As a result, the ferroelectric layer 230 containing hafnium zirconium oxide can be formed by an atomic layer deposition (ALD) method.

[0057] Referring to FIGS. 1 to 8, the method for manufacturing a ferroelectric capacitor according to the present invention may further include the step of forming an interface layer (S30).

[0058] The step of forming the interface layer (S30) can be performed by forming the interface layer 240 containing titanium oxide on the first electrode 220. The step of forming the ferroelectric layer (S20) can be performed after the step of forming the interface layer (S30). As a result, the method of manufacturing a ferroelectric capacitor according to the present invention can suppress the formation of oxygen vacancies in the ferroelectric layer 230 in the step of forming the ferroelectric layer (S20) by utilizing the oxygen scavenging effect of the titanium oxide formed through the step of forming the interface layer (S30). Therefore, the method of manufacturing a ferroelectric capacitor according to the present invention can further enhance the ferroelectric properties of the ferroelectric layer 230. In addition, the method of manufacturing a ferroelectric capacitor according to the present invention can manufacture a ferroelectric capacitor 200 that can be operated at a lower voltage by increasing the remanent polarization of the ferroelectric layer 230.

[0059] The step of forming the interface layer (S30) can be performed by treating the first electrode 220 with ozone to form an interface layer containing titanium oxide on the first electrode 220. As a result, the low concentration of oxygen vacancies resulting from the ozone treatment in the step of forming the interface layer (S30) can induce stable initial growth of the ferroelectric, thereby enhancing the ferroelectricity of the ferroelectric layer 230. The step of forming the interface layer (S30) can also be performed by forming the interface layer 240 containing titanium dioxide. In this case, compared to a comparative example in which the interface layer 240 containing titanium dioxide (TiO2) is formed on the first electrode 220 by deposition, the step of forming the interface layer (S30) can achieve a low concentration of oxygen vacancies due to the high ozone concentration in the initial growth stage by treating the first electrode 220 with ozone, thereby further enhancing the ferroelectricity due to more stable growth of the ferroelectric.

[0060] The step of forming the interface layer (S30) may be performed by treating the first electrode 220 with oxygen to form an interface layer containing titanium oxide on the first electrode 220. The low concentration of oxygen vacancies resulting from the oxygen treatment in the step of forming the interface layer (S30) may facilitate stable initial growth of the ferroelectric, thereby enhancing the ferroelectric properties of the ferroelectric layer 230. The step of forming the interface layer (S30) may be performed by forming the interface layer 240 containing titanium dioxide. In this case, compared to a comparative example in which the interface layer 240 containing titanium dioxide (TiO2) is formed on the first electrode 220 by deposition, the step of forming the interface layer (S30) may be performed by treating the first electrode 220 with ozone to achieve a high oxygen concentration in the initial growth phase, thereby achieving a low concentration of oxygen vacancies, thereby further enhancing the ferroelectric properties due to more stable growth of the ferroelectric.

[0061] Referring to FIGS. 1 to 8, the method for manufacturing a ferroelectric capacitor according to the present invention may further include a heat treatment step (S40).

[0062] The heat treatment step (S40) can be performed after the ferroelectric layer forming step (S20) is performed. The heat treatment step (S40) can be performed by heat treating the ferroelectric layer 230 with a nitrogen-containing gas. This can further improve the film quality of the ferroelectric layer 230 by crystallizing the ferroelectric layer 230. When the ferroelectric layer 230 contains hafnium zirconium oxide, the hafnium zirconium oxide can be crystallized by the heat treatment. The heat treatment step (S40) can also be performed by performing a PMA (Post Metallization Annealing) process on the ferroelectric layer 230 in a nitrogen-containing gas atmosphere at 500°C to 550°C for 10 to 20 seconds.

[0063] Although not shown in the drawings, the method for manufacturing a ferroelectric capacitor according to the present invention may further include forming a second electrode.

[0064] The step of forming the second electrode may be performed by forming the second electrode 250 on the ferroelectric layer 230. The second electrode 250 may include titanium nitride. The step of forming the second electrode may also be performed by forming the second electrode using a different material from the first electrode 220.

[0065] Referring to FIGS. 1 to 9, the method for manufacturing a ferroelectric capacitor according to the present invention may include a step (S50) of treating the interfacial layer with oxygen plasma.

[0066] The step (S50) of treating the interface layer with oxygen plasma can be performed after the step (S30) of forming the interface layer, and the step (S20) of forming the ferroelectric layer can be performed after the step (S50) of treating the interface layer with oxygen plasma.

[0067] The step of treating the interface layer with oxygen plasma (S50) can be performed by treating the interface layer 240 with oxygen plasma. As a result, the method for manufacturing a ferroelectric capacitor according to the present invention can remove impurities from the interface layer 240, thereby improving the film quality of the interface layer 240. Furthermore, the method for manufacturing a ferroelectric capacitor according to the present invention forms the ferroelectric layer 230 on the interface layer 240 that has been treated with oxygen plasma, thereby forming a ferroelectric layer 230 with improved film quality. The step of treating the interface layer with oxygen plasma (S50) can be performed by the spray unit 4 generating oxygen plasma. In this case, the spray unit 4 can generate plasma using the first plate 41 and the second plate 42 and spray oxygen through at least one of the first gas passage 4a and the second gas passage 4b.

[0068] 1 to 10, in the method for manufacturing a ferroelectric capacitor according to the present invention, the step of forming an interface layer (S30) can be performed by forming an interface layer 240 containing titanium oxynitride (TiON). Therefore, in the method for manufacturing a ferroelectric capacitor according to the present invention, the oxygen scavenging effect of titanium oxynitride formed through the step of forming the interface layer (S30) can be used to suppress the formation of oxygen vacancies in the ferroelectric layer 230 in the step of forming the ferroelectric layer (S20). Therefore, the method for manufacturing a ferroelectric capacitor according to the present invention can further enhance the ferroelectricity of the ferroelectric layer 230. Furthermore, the method for manufacturing a ferroelectric according to the present invention can manufacture a ferroelectric capacitor 200 that can be driven at a lower voltage by increasing the remanent polarization of the ferroelectric layer 230.

[0069] The step of forming the interface layer (S30) may include a step of injecting a source gas (S31), a step of injecting a first reacton gas (S32), and a step of injecting a second reacton gas (S33).

[0070] The source gas injection step (S31) can be performed by injecting a source gas containing titanium. This step (S31) can be performed by the injection unit 4 injecting the source gas containing titanium toward the substrate 210. The source gas containing titanium can be injected through the first gas passage 4a. The source gas injection step (S31) can perform an adsorption process in which titanium is adsorbed.

[0071] The step (S32) of injecting the first reacton gas can be performed by injecting the first reacton gas containing oxygen. This step (S32) can be performed by the injector 4 injecting the first reacton gas containing oxygen toward the substrate 210. The first reacton gas containing oxygen can be injected through the second gas passage 4b.

[0072] The step of injecting the second reacton gas (S33) can be performed by injecting a second reacton gas containing nitrogen. This step (S33) can be performed by injecting the second reacton gas containing nitrogen toward the substrate 210 using the injector 4. The second reacton gas containing nitrogen can be injected through the second gas passage 4b. The second reacton gas containing nitrogen can also be injected through the third gas passage. Through the steps of injecting the first reacton gas (S32) and injecting the second reacton gas (S33), the first reacton gas containing oxygen and the second reacton gas containing nitrogen react with the titanium adsorbed in the adsorption step, thereby depositing the interface layer 240 containing titanium oxynitride. In this case, the interface layer 240 can be formed by atomic layer deposition.

[0073] The step (S30) of forming the interface layer can include the step (S34) of injecting a first purge gas and the step (S35) of injecting a second purge gas.

[0074] The step of injecting the first purge gas (S34) can be performed by the injector 4 injecting the first purge gas. The first purge gas can be injected into the processing space 100 through at least one of the first gas passage 4a and the second gas passage 4b. The first purge gas can also be injected into the processing space 100 through at least one of the first gas passage 4a, the second gas passage 4b, and the third gas passage. The first purge gas can be an inert gas such as argon (Ar). The step of injecting the first purge gas (S34) can be performed after the step of injecting the source gas (S31). Thus, the step of injecting the first purge gas (S34) can perform a purge process of purging titanium and other materials not used in the adsorption process from the processing space 100. The step of injecting the first reacton gas (S32) can be performed after the step of injecting the first purge gas (S34) is performed.

[0075] The step of injecting the second purge gas (S35) can be performed by the injector 4 injecting the second purge gas. The second purge gas can be injected into the processing space 100 through at least one of the first gas passage 4a and the second gas passage 4b. The second purge gas can also be injected into the processing space 100 through at least one of the first gas passage 4a, the second gas passage 4b, and the third gas passage. The second purge gas can be an inert gas such as argon. The step of injecting the second purge gas (S35) can be performed after the step of injecting the second reacton gas (S33). Thus, the step of injecting the second purge gas (S33) can perform a purge process of purging nitrogen and other gases not used in the deposition process from the processing space 100. After the step of injecting the second purge gas (S35) is performed, the step of forming the ferroelectric layer (S20) or the step of treating the interface layer with oxygen plasma (S50) may be performed.

[0076] The step (S30) of forming the interface layer may also include the step (S36) of injecting a third purge gas.

[0077] The step of injecting the third purge gas (S36) can be performed by the injector 4 injecting the third purge gas. The third purge gas can be injected into the processing space 100 through at least one of the first gas passage 4a and the second gas passage 4b. The third purge gas can also be injected into the processing space 100 through at least one of the first gas passage 4a, the second gas passage 4b, and the third gas passage. The third purge gas can be an inert gas such as argon. The step of injecting the third purge gas (S36) can be performed after the step of injecting the first reacton gas (S32). Thus, the step of injecting the third purge gas (S36) can perform a purge process of purging oxygen and other gases not used in the deposition process from the processing space 100. The step of injecting the second reacton gas (S33) can be performed after the step of injecting the third purge gas (S36).

[0078] The present invention described above is not limited to the above-described embodiments and accompanying drawings, and it will be apparent to those skilled in the art to which the present invention pertains that various substitutions, modifications, and changes can be made without departing from the technical spirit of the present invention.

Claims

1. A method for manufacturing a ferroelectric capacitor, comprising: providing a substrate having a first electrode formed thereon, the first electrode comprising titanium nitride (TiN); The first electrode is heated with ozone (O ３ ) or oxygen (O ２ ) to form an interface layer comprising titanium oxide on the first electrode; and A method for manufacturing a ferroelectric capacitor, comprising forming a ferroelectric layer comprising hafnium (Hf) oxide or hafnium zirconium oxide (HZO) on the interfacial layer.

2. 2. The method for manufacturing a ferroelectric capacitor according to claim 1, wherein, when the step of forming the ferroelectric layer includes forming the ferroelectric layer containing hafnium oxide, the step of forming the ferroelectric layer further includes zirconium (Zr).

3. 2. The method for manufacturing a ferroelectric capacitor according to claim 1, wherein, when the step of forming the ferroelectric layer includes forming the ferroelectric layer containing the hafnium zirconium oxide, hafnium and zirconium are simultaneously supplied to the interface layer to form the ferroelectric layer containing the hafnium zirconium oxide on the interface layer.

4. 4. The method for manufacturing a ferroelectric capacitor according to claim 1, further comprising, after forming the ferroelectric layer, annealing the ferroelectric layer with a gas containing nitrogen.

5. The step of forming the interface layer comprises using titanium dioxide (TiO ２ 4. The method for manufacturing a ferroelectric capacitor according to claim 1, wherein the interfacial layer is formed to contain a ferroelectric material.

6. treating the interfacial layer with oxygen plasma; 4. The method for manufacturing a ferroelectric capacitor according to claim 1, wherein the step of forming the ferroelectric layer is carried out after the step of treating with oxygen plasma.

7. A method for manufacturing a ferroelectric capacitor, comprising: providing a substrate having a first electrode formed thereon, the first electrode comprising titanium nitride (TiN); forming an interfacial layer comprising titanium oxynitride (TiON) on the first electrode; and A method for manufacturing a ferroelectric capacitor, comprising forming a ferroelectric layer comprising hafnium (Hf) oxide or hafnium zirconium oxide (HZO) on the interfacial layer.

8. the step of forming the interface layer injecting a source gas containing titanium; injecting a first reacton gas containing oxygen; and 8. The method for manufacturing a ferroelectric capacitor according to claim 7, further comprising the step of injecting a second reacton gas containing nitrogen.

9. a first electrode comprising titanium nitride (TiN); a ferroelectric layer formed on the first electrode and including hafnium (Hf) oxide or hafnium zirconium oxide (HZO); and an interfacial layer disposed between the ferroelectric layer and the first electrode; The interface layer contains titanium oxide, and the first electrode is heated to ozone (O ３ ) or oxygen (O ２ ) .

10. The interface layer is made of titanium dioxide (TiO ２ 10. The ferroelectric capacitor of claim 9, comprising:

11. a first electrode comprising titanium nitride (TiN); a ferroelectric layer formed on the first electrode and including hafnium (Hf) oxide or hafnium zirconium oxide (HZO); and an interfacial layer disposed between the ferroelectric layer and the first electrode; A ferroelectric capacitor, wherein the interfacial layer comprises titanium oxynitride (TiON).

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