Method of forming capacitor electrodes

Abstract

A method of forming a capacitor electrode according to an exemplary embodiment of the present invention includes preparing a substrate, forming a first thin film containing titanium (Ti) by spraying a raw material containing titanium on the substrate, and forming a second thin film by spraying a raw material containing a noble metal element or copper (Cu) on the substrate. Thus, according to exemplary embodiments of the present invention, it is possible to suppress or prevent damage to the underlayer during electrode formation. In addition, it is possible to reduce the resistivity of the electrode, and the electrical characteristics of the electrode are improved. In addition, since damage to the bottom layer is suppressed or prevented and the electrical characteristics of the electrodes are improved, there is an effect of improving the quality characteristics of the capacitor.

Description

Technical Field

[0001] The present invention relates to a method of forming a capacitor electrode, and more particularly to a method of forming a capacitor electrode capable of suppressing or preventing damage to an underlying layer. Background Art

[0002] A capacitor suitable for a semiconductor device includes a bottom electrode formed on a substrate, a dielectric layer formed on the bottom electrode, and a top electrode formed on the dielectric layer. Here, each of the top electrode and the bottom electrode is formed by stacking a titanium nitride (TiN) film and a tungsten (W) film.

[0003] The titanium nitride (TiN) thin film is formed using a raw material including titanium tetrachloride (TiCl 4 ), and the tungsten (W) thin film is formed using a raw material including tungsten hexafluoride (WF 6 ).

[0004] However, when each of the titanium nitride (TiN) film and the tungsten (W) film is formed, chlorine (Cl) and fluorine (F) contained in the raw materials penetrate into the bottom layer, such as the contact layer made of metal oxide. Therefore, there is a defect that the bottom layer (ie, the contact layer) is damaged, and thus the characteristics of the capacitor are deteriorated.

[0005] (Prior Art Documents)

[0006] (Patent Document 1) Korean Patent No. 10-1110077 Summary of the invention

[0007] Technical issues

[0008] The present invention provides a method of forming a capacitor electrode capable of suppressing or preventing damage to an underlying layer.

[0009] The present invention also provides a method of forming a capacitor electrode capable of improving electrical characteristics.

[0010] Technical Solution

[0011] According to an exemplary embodiment, a method of forming a capacitor electrode includes preparing a substrate, forming a first thin film containing titanium by spraying a raw material containing titanium (Ti) on the substrate, and forming a second thin film by spraying a raw material containing a noble metal element or copper (Cu) on the substrate.

[0012] The formation of the first thin film and the formation of the second thin film may be repeated alternately.

[0013] The second thin film may be formed before the first thin film is formed.

[0014] In forming the first thin film, titanium nitride (TiN) atomic layer deposition may be performed continuously a plurality of times.

[0015] In the formation of the second thin film, a plurality of deposition cycles may be continuously performed.

[0016] The formation of the first thin film may be repeated more times than the formation of the second thin film.

[0017] A ratio ( T1 : T2 ) of the number of times ( T1 ) the formation of the first thin film is performed to the number of times ( T2 ) the formation of the second thin film is performed may be adjusted to 1:1 to 10:1.

[0018] The raw material containing the precious metal element may be a precursor containing at least one of ruthenium (Ru), platinum (Pt), gold (Au), silver (Ag), rhodium (Rh), palladium (Pd), terbium (Os), iridium (Ir), yttrium (Yi) and molybdenum (Mo).

[0019] The forming of the second thin film may include spraying a reducing gas after spraying a raw material containing a noble metal element or copper (Cu) and activating the reducing gas using plasma.

[0020] The forming of the second thin film may include spraying a reducing gas after spraying a raw material containing a noble metal element or copper (Cu) and exposing the substrate to plasma.

[0021] Beneficial Effects

[0022] According to the exemplary embodiment, it is possible to suppress or prevent damage to the underlying layer during electrode formation. In addition, it is possible to reduce the resistivity of the electrode, and there may be an effect of improving the electrical characteristics of the electrode.

[0023] Furthermore, since damage to the underlying layer is suppressed or prevented and the electrical characteristics of the electrode are improved, there is an effect of improving the quality characteristics of the capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The exemplary embodiments can be understood in more detail from the following description in conjunction with the accompanying drawings, in which:

[0025] Figure 1 is a diagram conceptually illustrating a capacitor having an electrode formed by a method of forming a capacitor electrode according to an exemplary embodiment.

[0026] Figure 2 is a diagram illustrating a bottom electrode formed on a substrate having an underlying layer formed on a top surface thereof by a method according to an exemplary embodiment.

[0027] Figure 3 is a conceptual diagram for describing a method of forming a bottom electrode by a method according to an exemplary embodiment.

[0028] Figure 4is a diagram illustrating a bottom electrode formed on a substrate having an underlying layer formed on a top surface thereof by a method according to a variation of the exemplary embodiment.

[0029] Figure 5 is a conceptual diagram for describing a method of forming a bottom electrode by a method according to a variation of the exemplary embodiment.

[0030] Figure 6 is a diagram illustrating a capacitor having a bottom electrode formed on a substrate having a groove formed therein. DETAILED DESCRIPTION

[0031] Below, exemplary embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the exemplary embodiments disclosed below, but will be implemented in various different forms. This exemplary embodiment is provided only to allow the present invention to be complete and to fully inform those with ordinary knowledge in the art of the scope of the present invention. The drawings may be exaggerated for the purpose of describing the exemplary embodiments of the present invention, and the same reference numerals in the drawings represent the same components.

[0032] Figure 1 is a diagram conceptually illustrating a capacitor having an electrode formed by a method of forming a capacitor electrode according to an exemplary embodiment.

[0033] refer to Figure 1 , the capacitor 100 may include a substrate 110, a bottom electrode 130 formed on the substrate 110, a dielectric layer 140 formed on the bottom electrode 130, and a top electrode 150 formed on the dielectric layer 140. In addition, the capacitor 100 may include a bottom layer 120 formed under the bottom electrode 130, and the bottom layer 120 may be, for example, a contact layer.

[0034] The substrate 110 may be a semiconductor substrate. For example, the substrate 110 may be a wafer, and may be any one of a silicon (Si) wafer, a GaAs wafer, and a silicon germanium (SiGe) wafer.

[0035] The bottom layer 120 is a layer formed between the substrate 110 and the bottom electrode 130 and may be, for example, a contact layer. The bottom layer 120 may be formed of a metal oxide, such as a silicon oxide (SiO2) film or an aluminum oxide (Al2O3) film.

[0036] The dielectric layer 140 may be formed between the bottom electrode 130 and the top electrode 150, and may be formed of a dielectric material including a metal oxide. In a more specific example, the dielectric layer 140 may be formed of any one of ZrO2, Al2O3, TiO2, TaO2, and HfO2. In addition, the dielectric layer 140 may be formed by an atomic layer deposition (ALD) method or a chemical vapor deposition (CVD) method.

[0037] At least one of the bottom electrode 130 and the top electrode 150 is formed by stacking a first thin film containing titanium (Ti) and a second thin film containing a noble metal element or copper (Cu).

[0038] When the second thin film is formed of a thin film containing a noble metal element, a precursor containing the noble metal element can be used as a raw material. More specifically, at least one of the bottom electrode 130 and the top electrode 150 is formed using a precursor containing at least one noble metal element of ruthenium (Ru), platinum (Pt), gold (Au), silver (Ag), rhodium (Rh), palladium (Pd), terbium (Os), iridium (Ir), yttrium (Yi) and molybdenum (Mo) as a raw material. More specifically, a precursor containing at least one of ruthenium (Ru), platinum (Pt), gold (Au), silver (Ag), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), yttrium (Yi) and molybdenum (Mo) and not containing chlorine (Cl) and fluorine (F) is used as a raw material.

[0039] For example, as a precursor material containing ruthenium (Ru), a precursor compound of ethylcyclopentadienyl ruthenium ((EtCp)2Ru) (di(ethylcyclopentadienyl)ruthenium) can be used. In addition, as a precursor material containing platinum (Pt), a material containing at least one of (trimethyl)(methylcyclopentadienyl)platinum and trimethyl(cyclopentadienyl)platinum can be used. As a precursor material containing gold (Au), for example, gold hydroxide (Au(OH)3) can be used. As a precursor material containing silver (Ag), for example, a material containing at least one of silver nitrate (AgNO3) and silver nitrite (AgNO2) can be used. As a precursor material containing rhodium (Rh), for example, a material containing tetrarhodium dodecacarbonyl (Rh4(CO) 12) material. As a precursor raw material containing palladium (Pd), for example, a material containing at least one of Pd(NO3)2, Pd(OAc)2 and Pd(acac)2 can be used. As a precursor raw material containing terbium (Os), for example, at least one of (methylcyclopentadienyl) terbium (methyl) (dicarbonyl) ((methylcyclopentadienyl) osmium (methyl) (dicarbonyl)), (ethylcyclopentadienyl) osmium (methyl) (dicarbonyl) ((ethylcyclopentadienyl) osmium (methyl) (dicarbonyl)) and (propylcyclopentadienyl) europium (methyl) (dicarbonyl) ((propylcyclopentadienyl) osmium (methyl) (dicarbonyl)) can be used. As a precursor raw material containing iridium (Ir), a material containing Ir(acac)3 and Ir4(CO) 12 As a precursor material containing yttrium (Yi), for example, tris-(methylcyclopentadienyl)yttrium can be used. The precursor material containing molybdenum (Mo) can be, for example, a material containing at least one of molybdenum hexacarbonyl and molybdenum pentachloride.

[0040] Thus, in an exemplary embodiment, when at least one of the bottom electrode 130 and the top electrode 150 is formed by forming a second film containing a noble metal element, a precursor containing at least one of ruthenium (Ru), platinum (Pt), gold (Au), silver (Ag), rhodium (Rh), palladium (Pd), terbium (Os), iridium (Ir), yttrium (Yi) and molybdenum (Mo) can be used as a raw material. Therefore, it is possible to suppress or prevent the layer formed under the electrode using the above raw materials from being damaged by chlorine (Cl) and fluorine (F). For example, when the bottom electrode 130 is formed using a precursor containing the aforementioned noble metal and not containing chlorine (Cl) and fluorine (F) as a raw material, it is possible to suppress or prevent the damage caused by chlorine (Cl) and fluorine (F) penetrating into the bottom layer 120 such as the contact layer when the bottom electrode 130 is formed. For another example, when a precursor containing the above-mentioned precious metal and not containing chlorine (Cl) and fluorine (F) is used as a raw material to form the top electrode 150, it is possible to suppress or prevent the layer located under the top electrode 150 (i.e., the dielectric layer 140) from being damaged by chlorine (Cl) and fluorine (F).

[0041] The formation of the second thin film using a precursor containing a noble metal element as a raw material has been described above, but the second thin film can be formed using a precursor containing copper (Cu) as a raw material. In this case, an organic metal compound or a material containing F or Cl can be used as a precursor raw material containing copper (Cu).

[0042] Here, as a precursor raw material containing copper (Cu) and being an organic metal compound, for example, a material containing at least one of di(2,2,6,6-tetramethyl-3,5-heptandionate) copper (II) (Cu(II)-2,2,6,6-tetramethyl-3,5-heptandionate) [Cu(thd)2] and di(hexafluoroacetylacetonate) copper (II) (Cu(II)-hexafluoroacetylacetonate) [Cu(hfac)2] can be used. In addition, as a copper precursor raw material containing F or Cl, a material containing at least one of CuCl1, CuCl2, CuF1, CuF2, CuBr1, CuBr2, CuI1 or CuI2 can be used.

[0043] In addition, copper (Cu) and precious metal elements such as ruthenium (Ru), platinum (Pt), gold (Au), silver (Ag), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), yttrium (Yi), and molybdenum (Mo) have lower resistivity than tungsten (W), which is a raw material used in the related art when using the top electrode 150 and the bottom electrode 130. Therefore, at least one of the top electrode 150 and the bottom electrode 130 formed using the above-mentioned precious metal materials can have a lower resistivity than in the related art, and thus has the effect of improving electrical characteristics.

[0044] Below, we will refer to Figure 2 and Figure 3 A method of forming a capacitor electrode by a method according to an exemplary embodiment is described. In this case, an example in which a bottom electrode 130 can be formed on a bottom layer 120 in a state where a bottom layer 120 made of a metal oxide is formed on a substrate 110 will be described. Furthermore, since the bottom electrode 130 and the top electrode 150 are formed by the same method, the method of forming the bottom electrode 130 will be described and a detailed description of the method of forming the top electrode 150 will be omitted.

[0045] Figure 2 is a diagram illustrating a bottom electrode formed on a substrate having an underlying layer formed on a top surface thereof by a method according to an exemplary embodiment. Figure 3 A conceptual diagram describing a method of forming a bottom electrode by a method according to an exemplary embodiment. In this case, Figure 3“Open” in the text may mean that a precursor or a gas is injected, and “closed” may mean that the injection of the precursor or the gas is stopped or ended.

[0046] refer to Figure 2 , the bottom electrode 130 may include a first thin film 131 containing titanium (Ti) and a second thin film 132 as a thin film formed on the first thin film 131 and containing a noble metal element. Here, the first thin film 131 may be, for example, a TiN thin film. Furthermore, the first thin film 131 may be formed by a deposition method using a raw material containing titanium (Ti), and the second thin film 132 may be formed by a deposition method using a raw material containing a noble metal element or copper (Cu).

[0047] The bottom electrode 130 may include a plurality of (or a plurality of) first thin films 131 and a plurality of (or a plurality of) second thin films 132. In this case, Figure 2 As shown, the first thin film 131 and the second thin film 132 may be alternately stacked to form the bottom electrode 130. In addition, the total number of layers of the first thin film 131 included in the bottom electrode 130 may be greater than the total number of layers of the second thin film 132. In addition, the number of first thin films 131 stacked continuously may be greater than the number of second thin films 132 stacked continuously. In addition, when forming the bottom electrode 130, as shown in FIG. Figure 2 As shown, the first film deposited may be the first film 131. In other words, when the bottom electrode 130 is formed on the bottom layer 120, the first film deposited on the top surface of the bottom layer 120 may be the first film 131.

[0048] refer to Figure 2 To describe a more specific example, five layers of the first thin film 131 may be formed on the top surface of the bottom layer 120, and then one layer of the second thin film 132 may be continuously formed on the first thin film 131, and the bottom electrode 130 may be formed by alternately repeating the formation of five layers of the first thin film 131 and the formation of one layer of the second thin film 132 multiple times. Therefore, the number of stacked first thin films 131 included in the bottom electrode 130 may be greater than the number of stacked second thin films 132 included therein, and the number of continuously stacked first thin films 131 may be greater than the number of continuously stacked second thin films 132.

[0049] An example in which the second film 132 does not continuously form a multi-layer structure but forms a layer or a single layer structure has been described above. However, the second film 132 is not limited thereto, and a multi-layer second film 132 may be continuously formed according to the number of films (i.e., first films 131) containing titanium (Ti) stacked continuously. For example, when ten layers of the first film 131 are continuously formed, five layers of the second film 132 may be continuously formed. That is, ten layers of the first film 131 may be formed on the top surface of the bottom layer 120, and then five layers of the second film 132 may be continuously formed on these first films 131, and the bottom electrode 130 may be formed by repeatedly alternating the formation of ten layers of the first film 131 and the formation of five layers of the second film 132.

[0050] Here, the multi-layered first thin film 131 or the multi-layered second thin film 132 is each formed by repeating a plurality of deposition cycles. In addition, in order to distinguish the first thin film 131 deposited by each deposition cycle from the first thin film 131 deposited by another deposition cycle, Figure 2 Although a multi-layer structure is shown in the figure, the stacked first films 131 may be an integrated film.

[0051] refer to Figure 3 The process of forming the bottom electrode 130 on the substrate 110 or the bottom layer 120 includes a process cycle C of forming a first film 131 and a second film 132. p In addition, process cycle C p That is, the process of forming the bottom electrode 130 includes a plurality of process cycles (C p :C p1 , C p2 ...C pn-1 , C pn ), and these process cycles (C p :C p1 , C p2 …C pn-1 , C pn ) each includes a first cycle C1 for depositing a first thin film 131 containing titanium (Ti) and a second cycle C2 for depositing a second thin film 132 containing a noble metal element or copper (Cu). In other words, these process cycles (C p :C p1 , C p2 ...C pn-1 , C pn ) each includes a process of forming a first thin film 131 and a process of forming a second thin film 132. Furthermore, the process of forming the first thin film 131 includes a first cycle C1, and the process of forming the second thin film 132 includes a second cycle C2.

[0052] In the following, for the convenience of description, these process cycles (C p :C p1 , C p2 ...C pn-1 , C pn ) can be respectively referred to as the first process cycle C p1 , Second process cycle C p2 ... the n-1th process cycle C pn-1 And the nth process cycle C pn Here, “n” may be the last round of process cycles. Furthermore, the last round n may be different according to the target number of process cycles, and the target number of process cycles may be changed according to the target thickness of the bottom electrode 130 to be manufactured.

[0053] Process cycle C for forming the bottom electrode 130 of the capacitor 100 p It includes a process of forming a first film 131 by spraying a raw material containing titanium (Ti) and a process of forming a second film 132 by spraying a raw material as a precursor containing a precious metal element or copper (Cu), and the process of forming the first film 131 and the process of forming the second film 132 can be performed alternately multiple times.

[0054] Below, we will refer to Figure 3 Describe the process cycle C in detail p At this time, the first process cycle C p1 The description will be given as an example.

[0055] refer to Figure 3 , the first process cycle C p1 The first cycle C1 includes depositing a first thin film 131 containing titanium (Ti) and a second cycle C2 for depositing a second thin film 132 containing a noble metal element or copper (Cu). At this time, the first cycle C1 can be performed earlier than the second cycle C2. Therefore, these process cycles C p Each of the first cycle C1 and the second cycle C2 may be performed in the order of “the first cycle C1 and the second cycle C2”.

[0056] Of course, the execution order of the first cycle C1 and the second cycle C2 may not be limited to this. That is, the second cycle C2 may be executed earlier than the first cycle C1. p Each of may be executed in the order of “the second loop C2 and the first loop C1”.

[0057] The first cycle C1 may include a process of spraying a first raw material containing titanium (Ti), a process of spraying a purge gas (first purge), a process of spraying a reactant, and a process of spraying a purge gas (second purge). That is, the first cycle C1 may be a cycle of performing "spraying a first raw material containing titanium (Ti), spraying a purge gas (first purge), spraying a reactant, and spraying a purge gas (second purge)". For example, a gas containing titanium tetrachloride (TiCl4) may be used as the first raw material containing titanium (Ti). Furthermore, a gas containing nitrogen (N) may be used as a reactant, such as a gas containing ammonia (NH3). In addition, argon (Ar) gas may be used as a purge gas. The TiN atomic layer (i.e., the first film 131) is deposited and formed by an atomic layer deposition (ALD) method through the first cycle C1.

[0058] The first cycle C1 of depositing the first thin film 131 in this manner may be referred to as a “TiN deposition cycle”.

[0059] The second cycle C2 may include a process of injecting a second raw material containing a noble metal element or copper (Cu), a process of injecting a purge gas (first purge), a process of injecting a reducing gas, and a process of injecting a purge gas (second purge).

[0060] At this time, the precious metal used as the second raw material may be a precursor containing at least one of ruthenium (Ru), platinum (Pt), gold (Au), silver (Ag), rhodium (Rh), palladium (Pd), europium (Os), iridium (Ir), yttrium (Yi) and molybdenum (Mo) and not containing chlorine (Cl) and fluorine (F). In addition, the second raw material as a precursor containing a precious metal element or copper (Cu) may be in a liquid or gaseous state.

[0061] Among the precursors containing precious metal elements used as the second raw material, the precursor containing ruthenium (Ru) can be ethylcyclopentadienylruthenium ((EtCp)2Ru)(di(ethylcyclopentadienyl)ruthenium, and for example, gold hydroxide (Au(OH)3) can be used as a precursor containing gold (Au).

[0062] For example, a material containing at least one of silver nitrate (AgNO3) and silver nitrite (AgNO2) can be used as a precursor containing silver (Ag). For example, a material containing Rh4(CO) 12As a precursor containing rhodium (Rh), a material containing at least one of Pd(NO3)2, Pd(OAc)2 and Pd(acac)2 can be used. As a precursor containing palladium (Pd), for example, a material containing at least one of (methylcyclopentadiene)terbium(methyl)(dicarbonyl), (ethylcyclopentadiene)terbium(methyl)(dicarbonyl) and (propylcyclopentadiene)terbium(methyl)(dicarbonyl) can be used as a precursor containing osmium (Os). Ir(acac)3 and Ir4(CO) can be used. 12 As a precursor containing iridium (Ir), at least one of the materials can be used. For example, yttrium tris-(methylcyclopentadienyl) can be used as a precursor containing yttrium (Yi). For example, a material containing at least one of molybdenum hexacarbonyl and molybdenum pentachloride can be used as a precursor containing molybdenum (Mo).

[0063] In addition, a material containing at least one of bis(2,2,6,6-tetramethyl-3,5-heptanedione)copper(II) [Cu(thd)2] and bis(hexafluoroacetylacetonate)copper(II) [Cu(hfac)2], or a material containing at least one of CuCl1, CuCl2, CuF1, CuF2, CuBr1, CuBr2, CuI1 or CuI2 can be used as a precursor containing copper (Cu).

[0064] Hereinafter, an example will be described in which a precursor containing a noble metal element is used as the second raw material and the second thin film 132 is formed of a noble metal element thin film. More specifically, an example will be described in which the second thin film 132 is formed of a ruthenium (Ru) thin film using a precursor containing ruthenium (Ru) as the second raw material.

[0065] As the purge gas, the same gas as that used in the first cycle C1 can be used. That is, argon (Ar) gas can be used as the purge gas.

[0066] The reducing gas is a gas sprayed to remove impurities included in the second film 132 (e.g., a ruthenium (Ru) film), and a gas containing oxygen (O) or hydrogen (H) may be used. More specifically, the gas containing oxygen (O) may be O2 gas, and the gas containing hydrogen (H) may be H2 gas. In addition, this reducing gas may be referred to as a gas that removes impurities.

[0067] It is preferred to generate plasma or apply heat to the film deposition space, such as the inside of the chamber, after or at the time of injecting the reducing gas. Therefore, the substrate can be subjected to plasma treatment or heat treatment. In addition, the reducing gas can be activated by the generated plasma or heat.

[0068] Thus, the second cycle C2 for forming the second film 132 includes "injection of the second raw material - injection of the purge gas (first purge) - injection of the reducing gas - injection of the purge gas (second purge)", and the second film 132 is deposited and formed through this second cycle C2. The second cycle C2 for forming the second film 132 using the raw material containing the precious metal element may be referred to as a "precious metal deposition cycle".

[0069] In an exemplary embodiment, when performing the first cycle C1 and the second cycle C2 as described above, a process cycle C p The number of times T1 of the first cycle C1 being executed in the process may be adjusted to be greater than the number of times T2 of the second cycle C2 being executed. p The number of execution times T2 of the process of forming the noble metal film can be adjusted to be smaller than the number of execution times T1 of the process of forming the TiN film.

[0070] At this time, the ratio T1:T2 of the number of times T1 of executing the first cycle C1 to the number of times T2 of executing the second cycle C2 can be adjusted to 1:1 to 10:1 (T1:T2=1:1 to 10:1). Preferably, the ratio T1:T2 of the number of times T1 of executing the first cycle C1 to the number of times T2 of executing the second cycle C2 can be adjusted to 3:1 to 8:1 (T1:T2=3:1 to 8:1). In other words, the ratio T1:T2 of the number of times T1 of the process of forming the TiN film is executed to the number of times T2 of the process of forming the precious metal film is executed can be adjusted to 1:1 to 10:1, preferably 3:1 to 8:1.

[0071] As described above, the first cycle C1 may be referred to as a "TiN film deposition cycle", and the second cycle C2 may be referred to as a "precious metal film cycle". Therefore, the ratio T1:T2 of the number of times T1 of performing the first cycle C1 to the number of times T2 of performing the second cycle C2 may be described as "the ratio T1:T2 of the number of times T1 of performing the TiN film deposition cycle C1 to the number of times T2 of performing the precious metal film deposition cycle C2". Therefore, the ratio T1:T2 of the number of times T1 of performing the TiN film deposition cycle C1 to the number of times T2 of performing the precious metal film deposition cycle C2 may be described as being adjusted to 1:1 to 10:1, preferably 3:1 to 8:1.

[0072] Hereinafter, for convenience of description, “the ratio T1:T2 of the number of times T1 of executing the first cycle C1 to the number of times T2 of executing the second cycle C2” will be abbreviated and described as “the first and second cycle execution times ratio T1:T2”.

[0073] To more specifically describe the method of forming the bottom electrode 130, reference will be made to Figure 3The following example describes a case where the ratio of the number of executions of the first and second loops is 5:1. Figure 3 , these process cycles (C p :C p1 , C p2 ...C pn-1 , C pn ) may include a first and a second loop C1, C2, wherein the ratio of the number of executions of the first and second loops T1:T2 may be 5:1. Figure 3 As shown, these process cycles (C p :C p1 , C p2 ...C pn-1 , C pn ) may include five first cycles C1 and one second cycle C2.

[0074] When the first process cycle C p1 When described as an example, the first cycle C1 is first performed five times. Figure 2 As shown, five layers of the first film 131 can be deposited on the substrate 110 or the bottom layer 120. Five first cycles (C1) can be performed continuously, and when the fifth first cycle C1 is completed, the second cycle C2 can be performed once. Therefore, a layer of the second film 132 (i.e., a ruthenium (Ru) film) can be deposited on the first film 131. Then, as described above, since the first cycle C1 is performed five times continuously and then the second cycle C2 is performed once, the ratio of the number of times the first and second cycles are performed T1:T2 is 5:1.

[0075] When the first process cycle C p1 The second process cycle C2 is completed in this way, and then the second process cycle C p2 At this time, the first process cycle C p1 The second process cycle C is executed with the same ratio of the first and second cycle execution times T1: T2. p2 That is, when executing the second process cycle C p2 When the first and second loop execution times ratio T1:T2 can be set to 5:1.

[0076] When the second process cycle C p2 At the end of the second cycle C2, the next process cycle C p3 ...C pn-1 , C pn can be executed in the same way. Figure 3 As shown, the process cycle can be executed until the required number n is reached.

[0077] As described above, in an exemplary embodiment, when the bottom electrode 130 is formed, the second thin film 132 is formed using a noble metal precursor that does not contain chlorine (Cl) and fluorine (F) when the second thin film 132 is formed. That is, the second thin film 132 is formed using a precursor containing at least one of ruthenium (Ru), platinum (Pt), gold (Au), silver (Ag), rhodium (Rh), palladium (Pd), chrysene (Os), iridium (Ir), yttrium (Yi) and molybdenum (Mo) and does not contain chlorine (Cl) and fluorine (F) as a second raw material. Therefore, it is possible to suppress or prevent damage to the bottom layer 120 (for example, a contact layer) formed under the bottom electrode 130 by chlorine (Cl) and fluorine (F). That is, when the bottom electrode 130 is formed, damage to the bottom layer 120 due to chlorine (Cl) and fluorine (F) can be suppressed or prevented. Therefore, the degradation of the characteristics of the capacitor 100 due to damage to the bottom layer 120 can be suppressed or prevented.

[0078] In addition, by forming the bottom electrode 130 according to the method of the exemplary embodiment, damage to the bottom layer 120 can be suppressed compared with the related art. More specifically, in the case of the exemplary embodiment, the first film 131 is first formed on the bottom layer 120 using a titanium tetrachloride (TiCl4) raw material, and the second film 132 containing a noble metal element can be formed on the TiN film. Therefore, when the first film 131 is formed on the bottom layer 120, a small amount of damage due to chlorine (Cl) may be generated.

[0079] However, this damage may be less than the damage of the method in the related art in which each of the two stacked layers is used as a raw material containing chlorine (Cl) and fluorine (F). That is, in the case of the related art, the TiN film is formed using a titanium tetrachloride (TiCl4) raw material, the tungsten (W) film is formed using a tungsten hexafluoride (WF6) raw material, and the bottom electrode is formed by alternately stacking the TiN film and the tungsten (W) film. In other words, one of the two films constituting the bottom electrode is formed using a raw material containing chlorine (Cl), and the other is formed using a raw material containing fluorine (F). Therefore, when the TiN film and the tungsten (W) film are formed, chlorine (Cl) and fluorine (F) may penetrate into the bottom layer and damage the bottom layer.

[0080] On the other hand, in the case of the exemplary embodiment, one of the thin films constituting the bottom electrode 130 (i.e., the first thin film 131 containing the noble metal element) is formed using a raw material that does not contain chlorine (Cl) and fluorine (F). Therefore, compared with the related art, it is possible to suppress damage to the bottom layer 120 due to chlorine (Cl) and fluorine (F) when the bottom electrode 130 is formed.

[0081] Furthermore, although it has been described above that the second thin film 132 is formed of a thin film containing a noble metal element, the second thin film 132 may be formed of a thin film containing copper (Cu).

[0082] As described above, since the bottom electrode 130 is formed to contain a noble metal element containing at least one of ruthenium (Ru), platinum (Pt), gold (Au), silver (Ag), rhodium (Rh), palladium (Pd), terbium (Os), iridium (Ir), yttrium (Yi), and molybdenum (Mo) or copper (Cu), it is possible to reduce the resistivity of the bottom electrode 130. That is, compared with the case in which the bottom electrode 130 is formed of tungsten (W) in the related art, the resistivity of the bottom electrode 130 can be reduced in the case of the exemplary embodiment, and thus there is an effect of improving electrical characteristics.

[0083] Figure 4 is a diagram illustrating a bottom electrode formed on a substrate having an underlying layer formed on a top surface thereof by a method according to a variation of the exemplary embodiment. Figure 5 is a conceptual diagram for describing a method of forming a bottom electrode by a method according to a variation of the exemplary embodiment.

[0084] In the above exemplary embodiment, it has been described that a process of depositing a TiN thin film may be performed first when forming the bottom electrode 130, that is, the first cycle C1. However, the formation of the bottom electrode 130 is not limited thereto, and a process of depositing a thin film containing a noble metal element or copper (Cu) may be performed first, that is, the second cycle C2. Therefore, the layer formed on the top surface of the bottom layer 120 or the layer formed to directly contact the bottom layer 120 may be as follows. Figure 4 The second film 132 is shown.

[0085] Below, we will refer to Figure 4 and Figure 5 A method of forming the bottom electrode 130 on the bottom layer 120 by a method according to a variation is described. Here, descriptions of components overlapping those described in the exemplary embodiment will be omitted or briefly described.

[0086] refer to Figure 5 The process of forming the bottom electrode 130 includes a process cycle C of forming a second film 132 and a first film 131 on the substrate 110 or the bottom layer 120. p In addition, the process of forming the bottom electrode 130 includes a plurality of process cycles C p .

[0087] These process cycles (C p :C p1 , C p2 ...C pn-1 , C pn ) each includes a second cycle C2 for forming the second film 132 and a first cycle C1 for forming the first film 131. That is, these process cycles (C p :C p1 , C p2...C pn-1 , C pn ) each includes a process for forming a thin film containing a noble metal element or copper (Cu) and a process for forming a thin film containing titanium (Ti).

[0088] At this time, the second cycle (C2) is first performed before the first cycle (C1) is performed. That is, the process of forming a thin film containing a noble metal element or copper (Cu) is first performed before the process of forming a TiN thin film. In other words, the second cycle C2 can be first performed so that the thin film deposited on the top surface of the bottom layer 120 or in contact with the bottom layer 120 is the second thin film 132.

[0089] Next, as in the above exemplary embodiment, the second cycle C2 and the first cycle C1 may be performed alternately for multiple times. p The number of times T2 of the second cycle C2 in the process can be adjusted to be less than the number of times T1 of the first cycle C1. p The number of times T2 of continuously executing the second cycle C2 may be adjusted to be less than the number of times T1 of continuously executing the first cycle C1.

[0090] In addition, the ratio T1:T2 of the number of times T1 of executing the first cycle C1 to the number of times T2 of executing the second cycle C2 can be adjusted to 1:1 to 10:1 (T1:T2=1:1 to 10:1), preferably 3:1 to 8:1 (T1:T2=3:1 to 8:1).

[0091] refer to Figure 5 More specifically, these process cycles (C p :C p1 , C p2 …C pn-1 , C pn ) may include one second cycle C2 and five first cycles C1. p1 When described as an example, the second loop C2 may be performed once. Then, as Figure 4 As shown, a layer of the second film 132 can be deposited on the bottom layer 120. When the second cycle C2 is completed once, the first cycle C1 can be performed five times. Therefore, five layers of the first film 131 are formed on the second film 132, such as a ruthenium (Ru) film. Then, as described above, since the second cycle C2 is performed once and then the first cycle C1 is performed five times, the ratio of the number of times the first and second cycles are performed T1:T2 is 5:1.

[0092] When the first process cycle C p1 The first cycle C1 is completed in this way, and then the second process cycle C p2At this time, the first process cycle C p1 The second process cycle C is executed with the same ratio of the first and second cycle execution times T1: T2. p2 is preferred.

[0093] When the second process cycle C p2 At the end of the second cycle C2, the next process cycle C p3 ...C pn-1 , C pn can be executed in the same way. Figure 5 As shown, the process cycle can be executed until the required number n is reached.

[0094] As described above, in the case of the variation, when the bottom electrode 130 is formed on the bottom layer 120 , the second thin film 132 is first formed by depositing the second raw material that does not contain chlorine (Cl) and fluorine (F).

[0095] Therefore, in the case of the variation, damage to the bottom layer 120 can be more effectively suppressed or prevented than in the exemplary embodiment. That is, in the case of the exemplary embodiment, the first film 131 is first formed on the bottom layer 120 using a titanium tetrachloride (TiCl4) raw material, and the second film 132 is formed on the first film 131. On the other hand, in the case of the variation, the second film 132 is first formed when the bottom electrode 130 is formed. That is, the second film 132 is first formed on the bottom layer 120 using a precursor containing at least one of ruthenium (Ru), platinum (Pt), gold (Au), silver (Ag), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), yttrium (Yi), and molybdenum (Mo) and not containing chlorine (Cl) and fluorine (F). Then, the first film 131 is formed on the second film 132 using titanium tetrachloride (TiCl4) as a raw material. Therefore, since the bottom layer 120 is covered by the second thin film 132, the bottom layer 120 may be prevented from being exposed to chlorine (Cl) when the first thin film 131 is formed. Therefore, damage to the bottom layer 120 may be suppressed or prevented more effectively than in the exemplary embodiment.

[0096] Figure 6 is a diagram illustrating a capacitor having a bottom electrode formed on a substrate having a groove formed therein.

[0097] In the above description, the formation of the bottom electrode 130 of the capacitor located on the flat substrate 110 has been described. However, the shape of the substrate is not limited thereto and can be formed by Figure 3 The method of the exemplary embodiment shown in Figure 6The bottom electrode 130 is formed on the substrate 110 having the groove 111 as shown in the figure to manufacture a capacitor. That is, the bottom layer 120 (for example, the contact layer) can be formed on the substrate 110 having the groove 111, and the bottom electrode 130 can be formed on the contact layer by the method according to the exemplary embodiment. Of course, when the bottom electrode is formed on the substrate 110 having the groove 111, the bottom electrode can be formed by the method according to the exemplary embodiment. Figure 5 The method of the variation example is formed without limitation Figure 3 An exemplary embodiment of the invention is described in detail below.

[0098] In the above, the case of forming the bottom electrode 130 of the capacitor 100 by the method according to the exemplary embodiment and the modified example is described as an example. However, the method according to the exemplary embodiment and the modified example may be applied to forming the top electrode 150 and may be applied to the top electrode 150 and the bottom electrode 130.

[0099] As described above, according to an exemplary embodiment, when forming at least one of the top electrode 150 and the bottom electrode 130, at least one of them can be formed by stacking the first film 131 and the second film 132. At this time, when forming the second film 132, the second film 132 can be formed using a precursor raw material containing a noble metal element and not containing chlorine (Cl) and fluorine (F). That is, the second film 132 is formed by using a precursor containing at least one of ruthenium (Ru), platinum (Pt), gold (Au), silver (Ag), rhodium (Rh), palladium (Pd), chrysene (Os), iridium (Ir), yttrium (Yi) and molybdenum (Mo) and not containing chlorine (Cl) and fluorine (F) as the second raw material. Therefore, it is possible to suppress or prevent the bottom layer 120 formed under the top electrode 150 or the bottom electrode 130 from being damaged by chlorine (Cl) and fluorine (F).

[0100] More specifically, when forming at least one of the top electrode 150 and the bottom electrode 130, the second thin film 132 is provided to contain at least one noble metal element of ruthenium (Ru), platinum (Pt), gold (Au), silver (Ag), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), yttrium (Yi), and molybdenum (Mo) or copper (Cu). Therefore, the resistivity of at least one of the top electrode 150 and the bottom electrode 130 can be reduced, and thus the electrical characteristics thereof can be improved.

[0101] Furthermore, since damage to the bottom layer 120 is suppressed or prevented and electrical characteristics of the electrode are improved, quality characteristics of the capacitor 100 may be improved.

[0102] Industrial Applicability

[0103] According to the embodiments of the present invention, damage to the underlying layer can be suppressed or prevented when forming an electrode. In addition, the specific resistance of the electrode can be reduced, thereby having the effect of improving the electrical properties of the electrode.

Claims

1. A method for forming a capacitor electrode, the method comprising: preparing a substrate; forming a first thin film containing titanium by spraying a raw material containing titanium (Ti) onto the substrate; as well as The second thin film is formed by spraying a raw material containing a noble metal element or copper (Cu) onto the substrate.

2. The method for forming a capacitor electrode according to claim 1, wherein: The formation of the first thin film and the formation of the second thin film are repeated alternately.

3. The method for forming a capacitor electrode according to claim 1, wherein: The second thin film is formed before the first thin film is formed.

4. The method for forming a capacitor electrode according to any one of claims 1 to 3, wherein: In forming the first thin film, TiN atomic layer deposition is performed continuously a plurality of times.

5. The method for forming a capacitor electrode according to any one of claims 1 to 3, wherein: In the formation of the second thin film, a plurality of deposition cycles are continuously performed.

6. The method for forming a capacitor electrode according to any one of claims 1 to 3, wherein: The formation of the first thin film is repeated more times than the formation of the second thin film.

7. The method for forming a capacitor electrode according to any one of claims 1 to 3, wherein: The ratio (T1:T2) of the number of times (T1) the formation of the first thin film is performed to the number of times (T2) the formation of the second thin film is performed is adjusted to 1:1 to 10:

1.

8. The method for forming a capacitor electrode according to any one of claims 1 to 3, wherein: The raw material containing the precious metal element is a precursor containing at least one of ruthenium (Ru), platinum (Pt), gold (Au), silver (Ag), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), yttrium (Yi) and molybdenum (Mo).

9. The method for forming a capacitor electrode according to any one of claims 1 to 3, wherein: The forming of the second thin film comprises: injecting a reducing gas after injecting the raw material containing a noble metal element or copper (Cu); and The reducing gas is activated using plasma.

10. The method for forming a capacitor electrode according to any one of claims 1 to 3, wherein: The forming of the second thin film comprises: injecting a reducing gas after injecting the raw material containing a noble metal element or copper (Cu); and The substrate is exposed to a plasma.

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