Ferroelectric capacitor and method of manufacturing ferroelectric capacitor

Abstract

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

Description

Technical Field

[0001] The present invention relates to a ferroelectric capacitor using a material having ferroelectricity and a method of manufacturing the ferroelectric capacitor. Background Art

[0002] Generally, a thin film layer, a thin film circuit pattern, or an optical pattern should be formed on a substrate for manufacturing a semiconductor device, a display device, a solar cell, etc. To this end, a processing process is performed on the substrate, and examples of the processing process include a deposition process of depositing a thin film containing a specific material on the substrate, an exposure process of selectively exposing a portion of the thin film by using a photosensitive material, an etching process of removing the selectively exposed portion of the thin film to form a pattern, and the like.

[0003] Ferroelectric capacitors using ferroelectrics can be manufactured through processing steps. Ferroelectrics are materials that have the property that their internal electric dipole moments align when no electric field is applied from the outside, thus maintaining spontaneous polarization.

[0004] Furthermore, in a ferroelectric capacitor using a ferroelectric, it is necessary to develop a technology that can improve the film quality of a ferroelectric layer formed by using the ferroelectric. Summary of the invention

[0005] Technical issues

[0006] The present invention is to solve the above-mentioned problems and to provide a ferroelectric capacitor and a method of manufacturing the ferroelectric capacitor, which can improve the film quality of the ferroelectric layer.

[0007] Technical Solution

[0008] In order to achieve the above-mentioned objects, the present invention may include the following elements.

[0009] According to the present invention, a ferroelectric capacitor may include: a first electrode, the first electrode includes titanium nitride (TiN); a ferroelectric layer, the ferroelectric layer is formed on the first electrode, and the ferroelectric layer includes hafnium (Hf) oxide or hafnium zirconium oxide (HZO); and an interface layer, the interface layer is arranged between the ferroelectric layer and the first electrode.

[0010] In the ferroelectric capacitor according to the present invention, the interface layer may include titanium oxide, and may be formed by treating the first electrode with ozone (O 3 ) or oxygen (O 2 ).

[0011] In the ferroelectric capacitor according to the present invention, the interface layer may contain titanium dioxide (TiO2).

[0012] The method for manufacturing a ferroelectric capacitor according to the present invention may include: a step of preparing a substrate having a first electrode including titanium nitride (TiN); a step of treating the first electrode with ozone (O3) or oxygen (O2) to form an interface layer including titanium oxide on the first electrode; and a step of forming a ferroelectric layer including hafnium (Hf) oxide or hafnium zirconium oxide (HZO) on the interface layer.

[0013] The method for manufacturing a ferroelectric capacitor according to the present invention may include: a step of preparing a substrate having a first electrode including titanium nitride (TiN); a step of forming an interface layer including titanium oxynitride (TiON) on the first electrode; and a step of forming a ferroelectric layer including hafnium (Hf) oxide or hafnium zirconium oxide (HZO) on the interface layer.

[0014] Beneficial Effects

[0015] According to the present invention, the following effects can be achieved.

[0016] The present invention can use an interface layer disposed between the first electrode and the ferroelectric layer, thereby preventing the formation of oxygen vacancies in the process of forming the ferroelectric layer. Therefore, the present invention can further enhance the ferroelectricity of the ferroelectric layer and increase the residual polarization value of the ferroelectric layer, thereby being implemented to be driven at a lower voltage.

[0017] The present invention can be implemented by supplying hafnium and zirconium simultaneously to form a ferroelectric layer comprising hafnium zirconium oxide (HZO). Therefore, the present invention can improve the film quality of the ferroelectric layer by using hafnium zirconium oxide. In addition, the present invention can supply hafnium and zirconium simultaneously to form the ferroelectric layer, thus helping to shorten the process time for forming the ferroelectric layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic block diagram of an embodiment of a substrate processing apparatus for manufacturing a ferroelectric capacitor according to the present invention.

[0019] Figure 2 and Figure 3 is a schematic side sectional view of a spray unit that sprays a gas in an embodiment of a substrate processing apparatus for manufacturing a ferroelectric capacitor according to the present invention.

[0020] Figure 4 is a schematic side cross-sectional view of a ferroelectric capacitor according to the present invention.

[0021] Figures 5 to 7 is a schematic side cross-sectional view showing a process of manufacturing a ferroelectric capacitor according to the present invention.

[0022] Figures 8 to 10 is a schematic flow chart of a method for manufacturing a ferroelectric capacitor according to the present invention. DETAILED DESCRIPTION

[0023] Hereinafter, embodiments of the ferroelectric capacitor according to the present invention will be described in detail with reference to the accompanying drawings. When describing embodiments of the present invention, when an arbitrary structure is described as being formed "on" or "under" another structure, this description should be interpreted as including the case where a third structure is provided between these structures and the case where these structures are in contact with each other.

[0024] Reference Figures 1 to 4 The ferroelectric capacitor 200 according to the present invention can be manufactured by performing 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 by using a ferroelectric having ferroelectricity.

[0025] The ferroelectric capacitor 200 according to the present invention may be manufactured by performing a processing process on the substrate processing apparatus 1. Before describing an embodiment of the ferroelectric capacitor 200 according to the present invention, an embodiment of the substrate processing apparatus 1 will be described in detail below.

[0026] The substrate processing apparatus 1 may include a chamber 2 , a substrate supporting unit 3 , and a spray unit 4 .

[0027] Reference Figures 1 to 3 , the chamber 2 provides a processing space 100. A processing process performed on a substrate 210 may be performed in the processing space 100. The processing space 100 may be disposed in the chamber 2. An exhaust port (not shown) that exhausts gas from the processing space 100 may be coupled to the chamber 2. The substrate support unit 3 and the injection unit 4 may be disposed in the chamber 2.

[0028] The substrate supporting unit 3 supports the substrate 210. The substrate supporting unit 3 may support one substrate 210, or may support a plurality of substrates 210. In the case where the substrate supporting unit 3 supports a plurality of substrates 210, a process of sequentially performing a processing process on the plurality of substrates 210 to manufacture a ferroelectric capacitor 200 on each substrate 210 may be performed. The substrate supporting unit 3 may be coupled to the chamber 2. The substrate supporting unit 3 may be disposed in the chamber 2.

[0029] The injection unit 4 injects gas toward the substrate support unit 3. The injection unit 4 may be connected to a supply unit (not shown). In this case, the injection unit 4 may inject gas supplied from the supply unit toward the substrate support unit 3. The injection unit 4 may be disposed in the chamber 2. The injection unit 4 may be disposed opposite to the substrate support unit 3. The injection unit 4 may be disposed above the substrate support unit 3. The processing space 100 may be disposed between the injection unit 4 and the substrate support unit 3. The injection unit 4 may be coupled to a cover (not shown). The cover may be coupled to the chamber 2 to cover the upper portion of the chamber 2.

[0030] The injection unit 4 may include a first gas flow path 4a and a second gas flow path 4b.

[0031] The first gas flow path 4a is used to inject the first gas. One side of the first gas flow path 4a can be connected to the supply unit by a pipe, a hose, etc. The other side of the first gas flow path 4a can be communicated with the processing space 100. Therefore, the first gas supplied from the supply unit can flow along the first gas flow path 4a, and then can be injected into the processing space 100 through the first gas flow path 4a. The first gas flow path 4a can be used as a flow path for enabling the first gas to flow, and can be used as an injection port for injecting the first gas into the processing space 100.

[0032] The second gas flow path 4b is used to inject the second gas. The second gas and the first gas can be different gases. For example, when the first gas is a source gas, the second gas can be a reaction gas. One side of the second gas flow path 4b can be connected to the supply unit by a pipeline, a hose, etc. The other side of the second gas flow path 4b can be connected to the processing space 100. Therefore, the second gas supplied from the supply unit can flow along the second gas flow path 4b, and then can be injected into the processing space 100 through the second gas flow path 4b. The second gas flow path 4b can be used as a flow path for enabling the second gas to flow, and can be used as an injection port for injecting the second gas into the processing space 100.

[0033] The second gas flow path 4b and the first gas flow path 4a may be provided to be spatially separated from each other. Therefore, the second gas supplied from the supply unit to the second gas flow path 4b may be ejected into the processing space 100 without passing through the first gas flow path 4a. The first gas supplied from the supply unit to the first gas flow path 4a may be ejected into the processing space 100 without passing through the second gas flow path 4b. The second gas flow path 4b and the first gas flow path 4a may eject gas toward different parts of the processing space 100.

[0034] For example, Figure 2 As shown, the spray unit 4 may include a first plate 41 and a second plate 42 .

[0035] The first plate 41 is disposed above the second plate 42. The first plate 41 and the second plate 42 may be disposed to be spaced apart from each other. A plurality of first gas holes 411 may be formed in the first plate 41. Each of the first gas holes 411 may be used as a path for enabling the first gas to flow. The first gas hole 411 may be included in the first gas flow path 4a. A plurality of second gas holes 412 may be formed in the second plate 42. Each of the second gas holes 412 may be used as a path for enabling the second gas to flow. The second gas hole 412 may be included in the second gas flow path 4b. A plurality of protrusion members 413 may be coupled to the first plate 41. The protrusion member 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 protrusion member 413.

[0036] A plurality of openings 421 may be formed in the second plate 42. The openings 421 may be formed to penetrate the second plate 42. The openings 421 may be respectively disposed at positions corresponding to the protruding members 413. Figure 2 As shown, the protrusion members 413 may be formed to have a length that enables the protrusion members 413 to be inserted into the openings 421, respectively. Although not shown, the protrusion members 413 may be formed to have a length that enables the protrusion members 413 to be respectively disposed above the openings 421. The protrusion members 413 may be formed to have a length that protrudes downward from the second plate 42. The second gas holes 412 may be provided to spray gas toward the upper surface of the second plate 42. Although not shown, the lower surface of the first plate 41 may be formed to be flat without the protrusion members 413.

[0037] For example, Figure 3 As shown, a plurality of first openings 422 and a plurality of second openings 423 may be formed in the second plate 42 .

[0038] The first openings 422 may be formed to penetrate the second plate 42. The first openings 422 may be connected to the first gas holes 411, respectively. In this case, the protrusion member 413 may be disposed to contact the top surface of the second plate 42. The first gas may be injected into the processing space 100 via the first gas holes 411 and the first openings 422. The first gas holes 411 and the first openings 422 may be included in the first gas flow path 4a.

[0039] The second openings 423 may be formed to penetrate the second plate 42. The second openings 423 may be connected to the buffer spaces 43 provided between the first plate 41 and the second plate 42, respectively. The second gas may be injected into the processing space 100 via the second gas holes 412, the buffer space 43, and the second openings 423. The second gas holes 412, the buffer space 43, and the second openings 423 may be included in the second gas flow path 4b.

[0040] Although not shown, in the case where the lower surface of the first plate 41 is formed flat without the protrusion member 413, each of 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, and then may be injected into the processing space 100 through the first gas hole 411 and the second gas hole 412. In this case, when the first gas is supplied through the first gas hole 411 and the second gas is supplied through the second gas hole 412 at the same time, 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 may be injected into the processing space 100 through the first opening 422 and the second opening 423.

[0041] In addition, the first openings 422 may be respectively 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 staggered positions. In this case, the first openings 422 and the first gas holes 411 may be disposed at non-overlapping positions, or may be only partially disposed at overlapping positions.

[0042] In addition, the second openings 423 may be respectively 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 staggered positions. In this case, the second openings 423 and the second gas holes 412 may be disposed at non-overlapping positions, or may be disposed only partially at overlapping positions.

[0043] In addition, the ejection unit 4 may generate plasma by using the second plate 42 and the first plate 41. In this case, plasma power such as radio frequency (RF) power may be applied to the first plate 41, and the second plate 42 may be grounded. The first plate 41 may be grounded, and the plasma power may be applied to the second plate 42.

[0044] The ferroelectric capacitor 200 according to the present invention may be manufactured through a processing procedure using the substrate processing apparatus 1. The ferroelectric capacitor 200 according to the present invention may include a first electrode 220 and a ferroelectric layer 230.

[0045] Reference Figures 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 be used as a lower electrode. The first electrode 220 may be manufactured by using the substrate processing apparatus 1. In this case, a source gas including titanium may be sprayed through the first gas flow path 4a. A reaction gas including nitrogen may be sprayed through the second gas flow path 4b.

[0046] Reference Figures 1 to 4 , a ferroelectric layer 230 is formed on the first electrode 220. The ferroelectric layer 230 can be manufactured by using a ferroelectric having ferroelectricity. The ferroelectric layer 230 can include hafnium (Hf) oxide. In this case, a source gas including hafnium can be sprayed through the first gas flow path 4a. A reactive gas including oxygen can be sprayed through the second gas flow path 4b. Therefore, the ferroelectric layer 230 can be formed by an atomic layer deposition (ALD) process.

[0047] The ferroelectric layer 230 may include hafnium and zirconium. When the ferroelectric layer 230 includes hafnium and zirconium, the ferroelectric layer 230 may be formed to include hafnium zirconium oxide (HZO). Therefore, in the ferroelectric capacitor 200 according to the present invention, the film quality of the ferroelectric layer 230 may be improved by using hafnium zirconium oxide. Hafnium and zirconium (Zr) may be supplied to the first electrode 220 at the same time, so that the ferroelectric layer 230 may be formed. In this case, compared with the comparative example in which the ferroelectric layer 230 is formed by supplying hafnium and zirconium in sequence, in the ferroelectric capacitor 200 according to the present invention, the ferroelectric layer 230 may be formed by supplying hafnium and zirconium at the same time, thereby contributing to shortening the process time for forming the ferroelectric layer 230. In this case, a source gas mixed with hafnium and zirconium may be sprayed through the first gas flow path 4a. That is, hafnium and zirconium may be supplied through a co-flow process. A reaction gas containing oxygen may be sprayed through the second gas flow path 4b. Therefore, the ferroelectric layer 230 including hafnium zirconium oxide may be formed by an atomic layer deposition (ALD) process.

[0048] The ferroelectric layer 230 may be formed on the first electrode 220, and then annealing may be performed by a gas containing nitrogen, so that the ferroelectric layer 230 may be implemented. The ferroelectric layer 230 may be crystallized by annealing, so that the ferroelectric capacitor 200 according to the present invention may be implemented to include the ferroelectric layer 230 having a further improved film quality. When the ferroelectric layer 230 includes hafnium zirconium oxide, the hafnium zirconium oxide may be crystallized by annealing. In addition, the ferroelectric layer 230 may be implemented by performing a post metallization annealing (PMA) process for 10 seconds (sec) to 20 seconds in an atmosphere of 500° C. to 550° C. based on a gas containing nitrogen.

[0049] Reference Figures 1 to 7 The ferroelectric capacitor 200 according to the present invention may further include an interface layer 240 .

[0050] 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.

[0051] The interface layer 240 may include titanium oxide. Therefore, by using the oxygenscavenging effect of titanium oxide, the interface layer 240 can prevent the formation of oxygen vacancies in the process of forming the ferroelectric layer 230. Therefore, the interface layer 240 can further enhance the ferroelectricity of the ferroelectric layer 230. In addition, the ferroelectric capacitor 200 according to the present invention can increase the residual polarization value of the ferroelectric layer 230, and thus can be implemented to be driven at a lower voltage. When the process of annealing the ferroelectric layer 230 or the initial step of growing the ferroelectric layer 230 by an atomic layer deposition (ALD) process is performed, the interface layer 240 can prevent the formation of oxygen vacancies.

[0052] The first electrode 220 may be treated with ozone (O3), and thus the first interface layer 240 may be implemented. In this case, the interface layer 240 may include titanium dioxide (TiO2). Since the first electrode 220 including titanium nitride is treated with ozone, a TiN layer may be formed on the first electrode 220. x O yand titanium dioxide film, and oxygen vacancies with a low concentration can be formed by a high ozone concentration based on the treatment with ozone. Therefore, when the concentration of oxygen vacancies is very high, in the process of forming the ferroelectric layer 230, the oxygen vacancies with a high concentration can interfere with the stability of the ferroelectric, thereby preventing the ferroelectricity of the ferroelectric layer 230 from being weakened. Therefore, the oxygen vacancies with a low concentration based on the treatment with ozone can induce the stable initial growth of the ferroelectric, so that the ferroelectricity of the ferroelectric layer 230 can be enhanced. In this case, compared with the comparative example of forming the interface layer 240 containing titanium dioxide (TiO2) by deposition on the first electrode 220, in the embodiment, because the first electrode 220 is treated with ozone, oxygen vacancies with a low concentration can be obtained by a high ozone concentration at the initial step of growth, so that the ferroelectricity can be further enhanced based on the more stable growth of the ferroelectric. The process of treating the first electrode 220 with ozone can be performed by performing ozone injection and plasma formation using the injection unit 4 of the substrate processing device 1.

[0053] The interface layer 240 may be implemented by treating the first electrode 220 with oxygen (O2). In this case, the interface layer 240 may include titanium dioxide (TiO2). Since the first electrode 220 including titanium nitride is treated with oxygen, TiN may be formed on the first electrode 220. x O y and titanium dioxide film, and oxygen vacancies with a low concentration can be formed by a high oxygen concentration based on the treatment with oxygen. Therefore, when the concentration of oxygen vacancies is very high, in the process of forming the ferroelectric layer 230, the oxygen vacancies with a high concentration can interfere with the stability of the ferroelectric, thereby preventing the ferroelectricity of the ferroelectric layer 230 from being weakened. Therefore, the oxygen vacancies with a low concentration based on the treatment with oxygen can induce the stable initial growth of the ferroelectric, so that the ferroelectricity of the ferroelectric layer 230 can be enhanced. In this case, compared with the comparative example of forming the interface layer 240 containing titanium dioxide (TiO2) by deposition on the first electrode 220, in the embodiment, because the first electrode 220 is treated with oxygen, oxygen vacancies with a low concentration can be obtained by a high oxygen concentration at the initial step of growth, so the ferroelectricity can be further enhanced based on the more stable growth of the ferroelectric. The process of treating the first electrode 220 with oxygen can be performed by performing oxygen injection and plasma formation using the injection unit 4 of the substrate processing equipment 1.

[0054] The interface layer 240 may be treated with oxygen (O2) plasma. Therefore, in the ferroelectric capacitor 200 according to the present invention, impurities and the like may be removed from the interface layer 240, and thus the film quality of the interface layer 240 may be improved. In addition, after the interface layer 240 is treated with oxygen plasma, the ferroelectric layer 230 may be formed on the interface layer 240, and thus the ferroelectric capacitor 200 according to the present invention may further improve the film quality of the ferroelectric layer 230. In this case, the oxygen plasma may be formed by the spray unit 4.

[0055] The interface layer 240 can be formed to include titanium oxynitride (TiON). Therefore, by using the deoxidation effect of titanium oxynitride, the interface layer 240 can prevent the formation of oxygen vacancies in the process of forming the ferroelectric layer 230. Therefore, the interface layer 240 can further enhance the ferroelectricity of the ferroelectric layer 230. In addition, the ferroelectric capacitor 200 according to the present invention can increase the residual polarization value of the ferroelectric layer 230, and thus can be implemented to be driven at a lower voltage. When the process of annealing the ferroelectric layer 230 or the initial step of growing the ferroelectric layer 230 by an atomic layer deposition (ALD) process is performed, the interface layer 240 can prevent the formation of oxygen vacancies.

[0056] In the case where the interface layer 240 is formed to include titanium oxynitride, the interface layer 240 may be formed by sequentially spraying a source gas including titanium, a first reaction gas including oxygen, and a second reaction gas including nitrogen. In this case, the source gas including titanium may be sprayed through the first gas flow path 4a, and the first reaction gas including oxygen and the second reaction gas including nitrogen may be sequentially sprayed through the second gas flow path 4b. The source gas including titanium may be sprayed through the first gas flow path 4a, the first reaction gas including oxygen may be sprayed through the second gas flow path 4b, and the second reaction gas including nitrogen may be sprayed through the third gas flow path (not shown).

[0057] Reference Figures 1 to 7 , the ferroelectric capacitor 200 may include a second electrode 250 .

[0058] 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 be used as an upper electrode. The second electrode 250 and the first electrode 220 may be formed to include different materials.

[0059] Hereinafter, an embodiment of a method of manufacturing a ferroelectric capacitor according to the present invention will be described in detail with reference to the accompanying drawings.

[0060] Reference Figures 1 to 8, the method for manufacturing a ferroelectric capacitor according to the present invention can be used to manufacture the 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.

[0061] First, a substrate having a first electrode 220 formed thereon is prepared (S10). Such step S10 may be performed by preparing a substrate having a first electrode 220 including titanium nitride formed thereon. Step S10 of preparing a substrate may be performed while the substrate 210 having a first electrode 220 including titanium nitride formed thereon is supported by the substrate supporting unit 3 of the substrate processing apparatus 1.

[0062] Subsequently, a ferroelectric layer 230 is formed on the first electrode 220 (S20). Such step S20 may be performed by forming the ferroelectric layer 230 on the first electrode 220 using a ferroelectric having ferroelectricity. The step S20 of forming the ferroelectric layer may be performed by forming the ferroelectric layer 230 containing hafnium oxide. In the case where the step S20 of forming the ferroelectric layer is performed by using the substrate processing apparatus 1, a source gas containing hafnium may be sprayed through the first gas flow path 4a, and then a reaction gas containing oxygen may be sprayed through the second gas flow path 4b, and the ferroelectric layer 230 may be formed. In this case, the ferroelectric layer 230 may be formed by an atomic layer deposition (ALD) process.

[0063] The step S20 of forming the ferroelectric layer may form the ferroelectric layer 230 further including zirconium. The step S20 of forming the ferroelectric layer may be performed by forming the ferroelectric layer 230 including hafnium zirconium oxide on the first electrode 220. Therefore, the method of manufacturing a ferroelectric capacitor according to the present invention may improve the film quality of the ferroelectric layer 230 by using hafnium zirconium oxide. The step S20 of forming the ferroelectric layer may simultaneously supply hafnium and zirconium to the first electrode 220 to form the ferroelectric layer 230 including hafnium zirconium oxide on the first electrode 220. In this case, compared with the comparative example in which hafnium and zirconium are sequentially supplied to form the ferroelectric layer 230, the method of manufacturing a ferroelectric capacitor according to the present invention may simultaneously supply hafnium and zirconium to form the ferroelectric layer 230, and thus the process time for forming the ferroelectric layer 230 may be shortened. Therefore, the method of manufacturing a ferroelectric capacitor according to the present invention may contribute to increasing the yield of the ferroelectric capacitor 200. In the case of performing step S20 of forming the ferroelectric layer by using the substrate processing device 1, a source gas mixed with hafnium and zirconium can be sprayed through the first gas flow path 4a. That is, hafnium and zirconium can be supplied through a co-flow process. In addition, after the source gas mixed with hafnium and zirconium is sprayed through the first gas flow path 4a, a reaction gas containing oxygen can be sprayed through the second gas flow path 4b. Therefore, a ferroelectric layer 230 containing hafnium zirconium oxide can be formed by an atomic layer deposition (ALD) process.

[0064] Reference Figures 1 to 8 The method for manufacturing a ferroelectric capacitor according to the present invention may further include a step S30 of forming an interface layer.

[0065] The step S30 of forming the interface layer can be performed by forming an interface layer 240 including titanium oxide on the first electrode 220. After the step S30 of forming the interface layer is performed, the step S20 of forming the ferroelectric layer can be performed. Therefore, the method for manufacturing a ferroelectric capacitor according to the present invention can prevent the formation of oxygen vacancies in the ferroelectric layer 230 in the step S20 of forming the ferroelectric layer by using the deoxidation effect of the titanium oxide formed by the step S30 of forming the interface layer. Therefore, the method for manufacturing a ferroelectric capacitor according to the present invention can further enhance the ferroelectricity of the ferroelectric layer 230. In addition, the method for manufacturing a ferroelectric capacitor according to the present invention can increase the residual polarization value of the ferroelectric layer 230, so that a ferroelectric capacitor 200 that can be driven at a lower voltage can be manufactured.

[0066] The step S30 of forming the interface layer can be performed by treating the first electrode 220 with ozone to form an interface layer containing titanium oxide on the first electrode 220. Therefore, in the step S30 of forming the interface layer, the oxygen vacancies with a low concentration based on the treatment with ozone can induce the stable initial growth of the ferroelectric, and thus the ferroelectricity of the ferroelectric layer 230 can be enhanced. The step S30 of forming the interface layer can be performed by forming the interface layer 240 containing titanium dioxide. In this case, compared with the comparative example of forming the interface layer 240 containing titanium dioxide (TiO2) by deposition on the first electrode 220, in the step S30 of forming the interface layer, because the treatment is performed with ozone, the oxygen vacancies with a low concentration can be obtained by the high ozone concentration at the initial step of growth, and thus the ferroelectricity can be further enhanced based on the more stable growth of the ferroelectric.

[0067] The step S30 of forming the interface layer can be performed by treating the first electrode 220 with oxygen to form an interface layer containing titanium oxide on the first electrode 220. Therefore, in the step S30 of forming the interface layer, the oxygen vacancies having a low concentration based on the treatment with oxygen can induce the stable initial growth of the ferroelectric, and thus the ferroelectricity of the ferroelectric layer 230 can be enhanced. The step S30 of forming the interface layer can be performed by forming the interface layer 240 containing titanium dioxide. In this case, compared with the comparative example of forming the interface layer 240 containing titanium dioxide (TiO2) by deposition on the first electrode 220, in the step S30 of forming the interface layer, since the treatment is performed with oxygen, the oxygen vacancies having a low concentration can be obtained by the high oxygen concentration at the initial step of growth, and thus the ferroelectricity can be further enhanced based on the more stable growth of the ferroelectric.

[0068] Reference Figures 1 to 8 The method for manufacturing a ferroelectric capacitor according to the present invention may further include an annealing step S40.

[0069] The annealing step S40 may be performed after the step of forming the ferroelectric layer is performed. The annealing step S40 may be performed by annealing the ferroelectric layer 230 with a gas containing nitrogen. Therefore, the annealing step S40 may crystallize the ferroelectric layer 230, and thus the film quality of the ferroelectric layer 230 may be further improved. When the ferroelectric layer 230 contains hafnium zirconium oxide, the hafnium zirconium oxide may be crystallized by annealing. In addition, the annealing step S40 may be performed by performing a post metallization annealing (PMA) process for 10 seconds to 20 seconds based on a gas containing nitrogen in an atmospheric environment at 500° C. to 550° C.

[0070] Although not shown, the method of manufacturing a ferroelectric capacitor according to the present invention may further include the step of forming a second electrode.

[0071] 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 be performed by forming the second electrode with a material different from that of the first electrode 220.

[0072] Reference Figures 1 to 9 , the method for manufacturing a ferroelectric capacitor according to the present invention may include step S50 of treating the interface layer with oxygen plasma.

[0073] After the step S30 of forming the interface layer, the step S50 of treating the interface layer with oxygen plasma may be performed. After the step S50 of treating the interface layer with oxygen plasma, the step S20 of forming the ferroelectric layer may be performed.

[0074] The step S50 of treating the interface layer with oxygen plasma can be performed by treating the interface layer 240 with oxygen plasma. Therefore, the method for manufacturing a ferroelectric capacitor according to the present invention can remove impurities from the interface layer 240, so that the film quality of the interface layer 240 can be improved. In addition, the method for manufacturing a ferroelectric capacitor according to the present invention can form a ferroelectric layer 230 on the interface layer 240 that has been treated with oxygen plasma, so that a ferroelectric layer 230 with further improved film quality can be formed. By using the injection unit 4, the step S50 of treating the interface layer with oxygen plasma can be performed by forming oxygen plasma. In this case, the injection unit 4 can form plasma by using the first plate 41 and the second plate 42, and oxygen can be injected through at least one of the first gas flow path 4a and the second gas flow path 4b.

[0075] Reference Figures 1 to 10 In the method for manufacturing a ferroelectric capacitor according to the present invention, the step S30 of forming an interface layer can be performed by forming an interface layer 240 containing titanium oxynitride (TiON). Therefore, the method for manufacturing a ferroelectric capacitor according to the present invention can prevent the formation of oxygen vacancies in the ferroelectric layer 230 in the step S20 of forming the ferroelectric layer by using the deoxidation effect of the titanium oxynitride formed by the step S30 of forming the interface layer. Therefore, the method for manufacturing a ferroelectric capacitor according to the present invention can further enhance the ferroelectricity of the ferroelectric layer 230. In addition, the method for manufacturing a ferroelectric capacitor according to the present invention can increase the residual polarization value of the ferroelectric layer 230, so that a ferroelectric capacitor 200 that can be driven at a lower voltage can be manufactured.

[0076] The step S30 of forming the interface layer may include a step S31 of injecting a source gas, a step S32 of injecting a first reaction gas, and a step S33 of injecting a second reaction gas.

[0077] The step S31 of spraying the source gas may be performed by spraying the source gas containing titanium. Such step S31 may be performed by spraying the source gas containing titanium toward the substrate 210 using the spray unit 4. The source gas containing titanium may be sprayed through the first gas flow path 4a. The adsorption process of adsorbing titanium may be performed by the step S31 of spraying the source gas.

[0078] The step S32 of spraying the first reaction gas may be performed by spraying the first reaction gas containing oxygen. Such step S32 may be performed by spraying the first reaction gas containing oxygen toward the substrate 210 using the spray unit 4. The first reaction gas containing oxygen may be sprayed through the second gas flow path 4b.

[0079] The step S33 of spraying the second reaction gas may be performed by spraying the second reaction gas containing nitrogen. Such a step S33 may be performed by spraying the second reaction gas containing nitrogen toward the substrate 210 using the spray unit 4. The second reaction gas containing nitrogen may be sprayed through the second gas flow path 4b. The second reaction gas containing nitrogen may also be sprayed through the third gas flow path. The deposition process of depositing the interface layer 240 containing titanium oxynitride when the first reaction gas containing oxygen and the second reaction gas containing nitrogen react with the titanium adsorbed through the adsorption process may be performed through the step S32 of spraying the first reaction gas and the step S33 of spraying the second reaction gas. In this case, the interface layer 240 may be formed by an atomic layer deposition process.

[0080] The step S30 of forming the interface layer may include a step S34 of spraying a first purge gas and a step S35 of spraying a second purge gas.

[0081] The step S34 of injecting the first purge gas may be performed by injecting the first purge gas using the injection unit 4. The first purge gas may be injected into the processing space 100 through at least one of the first gas flow path 4a and the second gas flow path 4b. The first purge gas may be injected into the processing space 100 through at least one of the first gas flow path 4a, the second gas flow path 4b, and the third gas flow path. The first purge gas may be an inert gas such as argon (Ar). After the step S31 of injecting the source gas is performed, the step S34 of injecting the first purge gas may be performed. Therefore, the purge process of blowing away titanium that has not been used in the adsorption process from the processing space 100 may be performed by the step S34 of injecting the first purge gas. After the step S34 of injecting the first purge gas is performed, the step S32 of injecting the first reaction gas may be performed.

[0082] The step S35 of spraying the second purge gas can be performed by spraying the second purge gas using the spray unit 4. The second purge gas can be sprayed into the processing space 100 through at least one of the first gas flow path 4a and the second gas flow path 4b. The second purge gas can be sprayed into the processing space 100 through at least one of the first gas flow path 4a, the second gas flow path 4b and the third gas flow path. The first purge gas can be an inert gas such as argon. After the step S33 of spraying the second reaction gas is performed, the step S35 of spraying the second purge gas can be performed. Therefore, the purge process of blowing away titanium that is not used in the deposition process from the processing space 100 can be performed by the step S33 of spraying the second purge gas. After the step S35 of spraying the second purge gas is performed, the step S20 of forming the ferroelectric layer or the step S50 of treating the interface layer with oxygen plasma can be performed.

[0083] The step S30 of forming the interface layer may include the step S36 of spraying a third purge gas.

[0084] The step S36 of injecting the third purge gas may be performed by injecting the third purge gas using the injection unit 4. The third purge gas may be injected into the processing space 100 through at least one of the first gas flow path 4a and the second gas flow path 4b. The third purge gas may be injected into the processing space 100 through at least one of the first gas flow path 4a, the second gas flow path 4b, and the third gas flow path. The third purge gas may be an inert gas such as argon. After the step S32 of injecting the first reaction gas is performed, the step S36 of injecting the third purge gas may be performed. Therefore, the purge process of blowing away titanium that is not used in the deposition process from the processing space 100 may be performed by the step S36 of injecting the third purge gas. After the step S36 of injecting the third purge gas is performed, the step S33 of injecting the second reaction gas may be performed.

[0085] The present invention described above is not limited to the above embodiments and drawings, and those skilled in the art will clearly understand that various modifications, variations and substitutions may be made without departing from the scope and spirit of the present invention.

Claims

1. A method for manufacturing a ferroelectric capacitor, the method comprising: a step of preparing a substrate formed with a first electrode including titanium nitride (TiN); treating the first electrode with ozone (O3) or oxygen (O2) to form an interfacial layer including titanium oxide on the first electrode; and A step of forming a ferroelectric layer including hafnium (Hf) oxide or hafnium zirconium oxide (HZO) on the interface layer.

2. The method for manufacturing a ferroelectric capacitor according to claim 1, wherein: In the case of forming the ferroelectric layer including hafnium oxide, the step of forming the ferroelectric layer forms the ferroelectric layer further including zirconium (Zr).

3. The method for manufacturing a ferroelectric capacitor according to claim 1, wherein: In the case of forming the ferroelectric layer including hafnium zirconium oxide, the step of forming the ferroelectric layer simultaneously supplies hafnium and zirconium to the interface layer to form the ferroelectric layer including hafnium zirconium oxide on the interface layer.

4. The method for manufacturing a ferroelectric capacitor according to any one of claims 1 to 3, further comprising a step of performing annealing with a gas containing nitrogen after forming the ferroelectric layer.

5. The method for manufacturing a ferroelectric capacitor according to any one of claims 1 to 3, wherein: The step of forming the interface layer forms the interface layer including titanium dioxide (TiO 2 ).

6. The method for manufacturing a ferroelectric capacitor according to any one of claims 1 to 3, further comprising the step of treating the interface layer with oxygen plasma, in, After performing the step of treating with oxygen plasma, the step of forming the ferroelectric layer is performed.

7. A method of manufacturing a ferroelectric capacitor, the method comprising: a step of preparing a substrate formed with a first electrode including titanium nitride (TiN); forming an interfacial layer including titanium oxynitride (TiON) on the first electrode; and A step of forming a ferroelectric layer including hafnium (Hf) oxide or hafnium zirconium oxide (HZO) on the interface layer.

8. The method for manufacturing a ferroelectric capacitor according to claim 7, wherein: The step of forming the interface layer comprises: a step of injecting a source gas containing titanium; a step of injecting a first reaction gas containing oxygen; and The step of injecting a second reaction gas including nitrogen.

9. A ferroelectric capacitor comprising: a first electrode comprising titanium nitride (TiN); a ferroelectric layer formed on the first electrode, the ferroelectric layer comprising hafnium (Hf) oxide or hafnium zirconium oxide (HZO); and an interface layer, the interface layer being disposed between the ferroelectric layer and the first electrode, The interface layer includes titanium oxide and is formed by treating the first electrode with ozone (O3) or oxygen (O2).

10. The ferroelectric capacitor of claim 9, wherein: The interfacial layer includes titanium dioxide (TiO2).

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

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