Laminated structures, methods for manufacturing the same, and electronic devices

Abstract

The present invention provides a laminated structure and electronic device that allows for easy orientation control of the dielectric film and prevents or suppresses the deficiency of high vapor pressure elements, even when forming a thick dielectric film containing high vapor pressure elements on a substrate. [Solution] A method for manufacturing a laminated structure comprises (b) forming a buffer film 12 made of a first metal compound containing Hf and epitaxially grown on a substrate 11, and (c) forming a dielectric film 15 having a perovskite-type structure or an ilmenite-type structure and epitaxially grown on the buffer film 12. Step (c) includes (c1) forming an amorphous second dielectric film on the buffer film 12 by vapor deposition at a second temperature lower than the first temperature at which the metal oxide MX21 crystallizes, and (c2) forming a dielectric film 15 made of crystallized metal oxide MX21 by heat-treating the second dielectric film at the first temperature after step (c1).

Description

[Technical Field]

[0001] This invention relates to a laminated structure, a method for manufacturing the same, and an electronic device. [Background technology]

[0002] Dielectric films made of lead zirconate titanate (Pb(Zr,Ti)O3) (hereinafter also known as PZT), which has excellent piezoelectric and ferroelectric properties, are being investigated. Such dielectric films are being applied to memory elements such as non-volatile memory (FeRAM), and MEMS (Micro Electro Mechanical Systems) technologies such as inkjet heads and acceleration sensors.

[0003] Japanese Patent Publication No. 6498821 (Patent Document 1) discloses a technology for a film structure comprising: a silicon substrate including a main surface consisting of (100) planes; a first film formed on the main surface, having a cubic crystal structure and including a (100) oriented zirconium oxide film; and a conductive film as a lower electrode formed on the first film, having a cubic crystal structure and including a (100) oriented platinum film. In the technology described in Patent Document 1, the film structure has a piezoelectric film formed on the conductive film as a lower electrode, having a tetragonal crystal structure and including a (001) oriented lead zirconate titanate film.

[0004] Japanese Patent Publication No. 2008-047568 (Patent Document 2) describes a technique for crystallizing a ferroelectric film by using a PLZT{(Pb,La)(Zr,Ti)O3} target on a Pt base electrode, depositing the film in an amorphous state, then performing RTA (rapid thermal annealing) heat treatment at 650°C or lower, for example, 560°C, in an atmosphere containing Ar and O2, and further performing RTA heat treatment at 750°C in an oxygen atmosphere. Japanese Patent Publication No. 2002-190578 (Patent Document 3) describes a technique for depositing a PZT film on a Pt base electrode by RF magnetron sputtering at room temperature, and then crystallizing the amorphous PZT film into a perovskite phase by an RTA (Rapid Thermal Annealing) process. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 6498821 [Patent Document 2] Japanese Patent Publication No. 2008-047568 [Patent Document 3] Japanese Patent Publication No. 2002-190578 [Non-patent literature]

[0006] [Non-Patent Document 1] The Chemical Society of Japan (ed.), "Chemical Handbook: Basic Edition," 5th revised edition, Maruzen Co., Ltd., February 2004, pp. II-291-II-300. [Overview of the project] [Problems that the invention aims to solve]

[0007] In the technology described in Patent Document 1 above, a film containing a precursor is formed by coating a substrate with a raw material solution for a PZT film, the solution is evaporated to dry the film, and then the precursor is oxidized and crystallized by heat treatment at 600-700°C for 60 seconds in an oxygen atmosphere, thereby forming a 30 nm PZT film as a piezoelectric film by coating. This piezoelectric film contains PZT oriented at (001) in tetragonal representation, or at (100) in pseudocubic representation. However, when forming a PZT film thicker than 30 nm by coating, the PZT film becomes less likely to be oriented at (100) in pseudocubic representation, for example, and the piezoelectric properties of the piezoelectric film cannot be improved.

[0008] Furthermore, while the coating method involves forming a film containing a precursor, drying the film, and then heat-treating it to crystallize it, the vapor deposition method allows for the continuous deposition of PZT films, thus shortening the turn-around time (TAT) required to complete the product. However, when forming PZT films thicker than 30 nm using the vapor deposition method rather than the coating method, it is necessary to form the PZT film under a vacuum atmosphere at a high temperature, for example, around 400°C or higher, in order to epitaxially grow the PZT film and orient it to (100) in pseudocubic crystal representation. Therefore, if the piezoelectric film contains elements with high vapor pressure, such as Pb, the deficiency of these elements may reduce insulation and potentially degrade piezoelectric properties.

[0009] The present invention aims to provide a laminated structure having a dielectric film formed on a substrate and an electronic device equipped with the laminated structure, which allows for easy orientation control of the dielectric film while shortening the turnaround time (TAT), preventing or suppressing defects of the high vapor pressure element, and improving the insulating properties of the dielectric film, even when forming a dielectric film containing an element with a high vapor pressure and a thick film thickness on the substrate. [Means for solving the problem]

[0010] As a result of diligent research, the inventors have found that the above problem can be solved by the following configuration. [1] (a) Steps to prepare the substrate, (b) A step of forming an epitaxially grown first film on the substrate, (c) A step of forming a first dielectric film epitaxially grown on the first film, In a method for manufacturing a laminated structure having, In step (b) above, the first film is formed, which consists of a first metal compound containing Hf. In step (c) above, the first dielectric film is formed, which is made of a first metal oxide having a perovskite-type structure or an ilmenite-type structure. The aforementioned step (c) is, (c1) A step of forming a second dielectric film on the first film by vapor deposition, at a second temperature lower than the first temperature at which the first metal oxide crystallizes and at which the first metal oxide does not crystallize. (c2) After step (c1), a step of forming a first dielectric film consisting of the first metal oxide in which the second metal oxide has crystallized by heat treatment of the second dielectric film at a first temperature, A method for manufacturing a laminated structure, including [the specified element]. [2] In the method for manufacturing a laminated structure described in [1], (d) A step of forming a first conductive film epitaxially grown on the first film, It has, In step (c) above, the first dielectric film is formed on the first conductive film. A method for manufacturing a laminated structure, wherein step (c1) involves forming the second dielectric film on the first conductive film. In the method for manufacturing a laminated structure described in [3][2], In step (a) above, a substrate is prepared, which is a Si(100) substrate including a main surface made of a Si(100) plane, or an SOI substrate including a substrate made of a Si substrate, an insulating layer on the substrate, and an SOI layer on the insulating layer made of a Si(100) film and including the main surface made of a Si(100) plane. In the step (b), a first film made of a third metal oxide containing one or more metal elements selected from the group consisting of Hf and group 4 elements other than Hf and having a (100) orientation in the pseudo-cubic crystal representation, or a first metal nitride containing one or more metal elements selected from the group consisting of Hf and group 4 elements other than Hf and having a (100) orientation in the pseudo-cubic crystal representation is formed on the main surface. In the step (d), a first conductor film made of a platinum group element having a cubic crystal structure and a (100) orientation is formed. A method for manufacturing a laminated structure, in which in the step (c2), a first dielectric film made of the first metal oxide having a (100) orientation in the pseudo-cubic crystal representation is formed. [4] In the method for manufacturing a laminated structure according to [3], in the step (c2), a first dielectric film made of the first metal oxide represented by the following composition formula (Chemical Formula 1) is formed. Pb(Zr 1-x Ti x )O3···(Chemical Formula 1) where x satisfies 0 ≦ x ≦ 1. A method for manufacturing a laminated structure. [5] In the method for manufacturing a laminated structure according to [4], in the step (c2), a first dielectric film made of the first metal oxide having a cubic crystal structure and a (100) orientation is formed. A method for manufacturing a laminated structure. [6] In the method for manufacturing a laminated structure according to [5], in the step (b), a first film including a first portion and a second portion different from the first portion is formed. The first portion is made of a fourth metal oxide containing one or more metal elements selected from the group consisting of group 4 elements other than Hf. The second portion is made of a fifth metal oxide containing Hf. A method for manufacturing a laminated structure. [7] In the method for manufacturing a laminated structure according to [6], The first portion comprises the fourth metal oxide, which includes one or more metallic elements selected from the group consisting of Group 4 elements other than Hf, and one or more metallic elements selected from the group consisting of Nb, Ta, Si, rare earth elements, Al, and Group 2 elements. The second part is a method for manufacturing a laminated structure, comprising the fifth metal oxide containing Hf and one or more metal elements selected from the group consisting of Nb, Ta, Si, rare earth elements, Al, and group 2 elements. In the method for manufacturing a laminated structure described in [8] [6] or [7], A method for manufacturing a laminated structure, wherein in step (c2), the fourth metal oxide has a cubic crystal structure and is (100) oriented, and the fifth metal oxide has a cubic crystal structure and is (100) oriented, and the first dielectric film is formed in this state. In the method for manufacturing the laminated structure described in [9] [8], A method for manufacturing a laminated structure, wherein step (b) above is to form a first film comprising a first portion made of the fourth metal oxide having a cubic crystal structure and being (100) oriented, and a second portion made of the fifth metal oxide having a tetragonal crystal structure and being (001) oriented. In the method for manufacturing a laminated structure described in

[10] [9], A method for manufacturing a laminated structure, wherein in step (c1), the fourth metal oxide has a tetragonal crystal structure and is (001) oriented, and the fifth metal oxide has a cubic crystal structure and is (100) oriented, in which case the second dielectric film is formed. In the method for manufacturing the laminated structure described in

[11]

[10] , The (c2) step is, (c3) A step of heat-treating the second dielectric film at a temperature higher than the second temperature and lower than a third temperature between the first temperature and the second temperature. Includes, A method for manufacturing a laminated structure, wherein in step (c3), the fourth metal oxide has a cubic crystal structure and is (100) oriented, and the fifth metal oxide has a tetragonal crystal structure and is (001) oriented, and the second dielectric film is heat-treated. In the method for manufacturing a laminated structure described in

[12] [5], In step (c2), along the main surface of the first metal oxide <100> The direction is along the main surface which is the Si(100) plane of the substrate. <110> A method for manufacturing a laminated structure, comprising forming the first dielectric film, which is made of the first metal oxide, oriented parallel to the direction.

[13] In a method for manufacturing a laminated structure described in any of [1] to [5], The first temperature is 500 to 750°C. A method for manufacturing a laminated structure, wherein the second temperature is 50 to 300°C.

[14] In a method for manufacturing a laminated structure described in any of [1] to [5], In step (c2), the second dielectric film is heated from room temperature to the first temperature at a heating rate of 5 to 200°C / second, and then heat-treated at the first temperature. A method for manufacturing a laminated structure, including [the specified element]. In the method for manufacturing the laminated structure described in

[15]

[11] , A method for manufacturing a laminated structure, wherein the third temperature is the temperature at which the fourth metal oxide has a cubic crystal structure and is (100) oriented, and the fifth metal oxide has a tetragonal crystal structure and is (001) oriented.

[16] A substrate including the main surface, A first film epitaxially grown on the main surface, A first conductive film epitaxially grown on the first film, A first dielectric film epitaxially grown on the first conductive film, In a laminated structure having, The substrate comprises a Si(100) substrate including the main surface which is made of a Si(100) plane, or an SOI substrate comprising a substrate made of a Si substrate, an insulating layer on the substrate, and an SOI layer on the insulating layer which is made of a Si(100) film and includes the main surface which is made of a Si(100) plane. The first conductive film has a cubic crystal structure and is composed of (100)-oriented platinum group elements. The first film is, Part 1 and, The second part differs from the first part mentioned above, Includes, The first part comprises a first metal oxide containing one or more metallic elements selected from the group consisting of Group 4 elements other than Hf. The second part consists of a second metal oxide containing Hf, The first metal oxide has a cubic crystal structure and is (100) oriented, The second metal oxide has a cubic crystal structure and is (100) oriented. The first dielectric film consists of a third metal oxide represented by the following compositional formula (Chemical Formula 1), Pb(Zr 1-x Ti x )O3...(Chemical 1) The aforementioned x satisfies 0 ≤ x ≤ 1, The third metal oxide is a laminated structure having a cubic crystal structure and being (100) oriented. In the laminated structure described in

[17]

[16] , The first portion comprises a first metal oxide containing one or more metallic elements selected from the group consisting of Group 4 elements other than Hf, and one or more metallic elements selected from the group consisting of Nb, Ta, Si, rare earth elements, Al, and Group 2 elements. The second part is a laminated structure comprising the second metal oxide containing Hf and one or more metal elements selected from the group consisting of Nb, Ta, Si, rare earth elements, Al, and group 2 elements.

[18] An electronic device comprising the stacked structure described in

[16] or

[17] . [Effects of the Invention]

[0011] The laminated structure, its manufacturing method, and the electronic device equipped with the laminated structure of the present invention allow for easy orientation control of the dielectric film while shortening the turnaround time (TAT), preventing or suppressing defects of the high vapor pressure elements, and improving the insulating properties of the dielectric film, even when forming a dielectric film containing high vapor pressure elements and having a thick film thickness on a substrate. [Brief explanation of the drawing]

[0012] [Figure 1] This is a cross-sectional view showing an example of a laminated structure according to Embodiment 1. [Figure 2] This is a cross-sectional view showing another example of the laminated structure of Embodiment 1. [Figure 3] This figure shows an example of the first and second parts of the laminated structure according to Embodiment 1. [Figure 4] This is a cross-sectional view of the laminated structure of Embodiment 1 during the manufacturing process. [Figure 5] This is a cross-sectional view of the laminated structure of Embodiment 1 during the manufacturing process. [Figure 6] This is a cross-sectional view of the laminated structure of Embodiment 1 during the manufacturing process. [Figure 7] This is a cross-sectional view of the laminated structure of Embodiment 1 during the manufacturing process. [Figure 8] This is a cross-sectional view of the laminated structure of Embodiment 1 during the manufacturing process. [Figure 9] This diagram schematically shows the relationship between the film deposition temperature and crystal structure of ZrO2 and HfO2. [Figure 10] This is a cross-sectional view of the electronic device according to Embodiment 2. [Figure 11] This graph shows the diffraction pattern of the laminated structure of Example 1. [Figure 12] This graph shows the φ scan of the laminated structure in Example 1. [Figure 13] This graph shows the diffraction pattern of the laminated structure of Example 1. [Figure 14] This graph shows the diffraction pattern of the laminated structure of Example 1. [Figure 15] This graph shows the φ scan of the laminated structure in Example 1. [Figure 16] This graph shows the diffraction pattern of the laminated structure in Example 2. [Figure 17] This graph shows the temperature dependence of the c-axis length of cubic ZrO2 or HfO2. [Figure 18] This graph shows the temperature dependence of the c-axis length of tetragonal ZrO2 or HfO2. [Figure 19]This graph shows the temperature dependence of the c-axis length of PZT. [Figure 20] This graph shows the diffraction pattern of the laminated structure in Example 2. [Figure 21] This figure shows the results of identifying the lattice constants and crystal structures of ZrO2, HfO2, and PZT. [Modes for carrying out the invention]

[0013] The embodiments of the present invention will be described below with reference to the drawings.

[0014] (Embodiment 1) <Laminated structure> First, the laminated structure of Embodiment 1 will be described. Figure 1 is a cross-sectional view showing an example of the laminated structure of Embodiment 1. Figure 2 is a cross-sectional view showing another example of the laminated structure of Embodiment 1. Figure 3 is a diagram showing an example of the first and second parts in the laminated structure of Embodiment 1.

[0015] The laminated structure 10 shown in Figures 1 and 2 comprises a substrate 11 including a main surface 11p, a buffer film (first film) 12 formed on the main surface 11p, a conductive film (first conductive film) 13 epitaxially grown on the buffer film 12, a conductive film 14 epitaxially grown on the conductive film 13, a dielectric film (first dielectric film) 15 epitaxially grown on the conductive film 14, and a conductive film 16 formed on the dielectric film 15.

[0016] In this specification, "epitaxial growth" means that the film is oriented in all three mutually orthogonal directions, i.e., oriented in three dimensions.

[0017] In the example shown in Figure 1, the substrate 11 is made of a silicon (Si)(100) substrate including a main surface 11p made of a Si(100) plane. In the example shown in Figure 2, the substrate 11 is made of an SOI substrate including a base body 11a made of a Si substrate, an insulating layer 11b on the base body 11a, and an SOI (Silicon On Insulator) layer 11c on the insulating layer 11b made of a Si(100) film and including a main surface 11p made of a Si(100) plane. The conductive film 13 is made of platinum group elements such as Pt having a cubic crystal structure and being (100) oriented. The conductive film 14 contains strontium ruthenate (SrRuO3) oriented in a pseudocubic crystal representation. Hereafter, strontium ruthenate may be referred to as SRO. The conductive film 16 is made of platinum group elements such as Pt.

[0018] In this specification, when a metal oxide is described as being (100) oriented in pseudocubic crystal representation, it means that the metal oxide has a cubic crystal structure at room temperature and is (100) oriented, or that even if it has a tetragonal or monoclinic crystal structure at room temperature, it undergoes a phase transition at high temperatures to have a cubic crystal structure and is (100) oriented.

[0019] As shown in Figures 1 and 2, the buffer film 12 includes a first portion PR1 and a second portion PR2 which is different from the first portion PR1. The first portion PR1 consists of a metal oxide MX11 containing one or more metal elements selected from the group consisting of Group 4 elements other than Hf. The second portion PR2 consists of a metal oxide MX12 containing Hf. The metal oxide MX11 has a cubic crystal structure and is (100) oriented, and the metal oxide MX12 has a cubic crystal structure and is (100) oriented.

[0020] In the example shown in Figure 3, the first portion PR1 is exemplified as a portion consisting of ZrO2 having a cubic crystal structure and being (100) oriented, and the second portion PR2 is exemplified as a portion consisting of HfO2 having a tetragonal crystal structure and being (001) oriented. Furthermore, in the first portion PR1, four of the eight Zr atoms in the unit cell UC1, which is a face-centered cubic lattice consisting of two face-centered cubic lattices made of ZrO2, are replaced with Hf, thereby generating a unit cell UC2, which is a body-centered tetragonal lattice consisting of HfO2 and having a tetragonal crystal structure.

[0021] Furthermore, for the first part PR1 and the second part PR2, it is sufficient that the Zr / Hf ratio and crystal structure differ between the first part PR1 and the second part PR2. Therefore, the example shown in Figure 3 illustrates possible examples for the first part PR1 and the second part PR2 for the sake of ease of understanding, and the structures of the first part PR1 and the second part PR2 are not particularly limited.

[0022] The dielectric film 15 consists of a metal oxide MX21 represented by the following compositional formula (Chemical Formula 2). Pb(Zr 1-x Ti x )O3...(Chemical 2) In the above compositional formula (Chemical Formula 2), x satisfies 0 ≤ x ≤ 1. Furthermore, the metal oxide MX21 has a cubic crystal structure and is (100) oriented. Note that the above compositional formula (Chemical Formula 2) is identical to the above compositional formula (Chemical Formula 1). In the following text, the metal oxide represented by the above compositional formula (Chemical Formula 2) may be referred to as lead zirconate titanate (PZT).

[0023] In this embodiment 1, the laminated structure 10 does not necessarily have a conductive film 14 containing SRO oriented (100) in a pseudocubic crystal representation. However, since both the SRO contained in the conductive film 14 and the PZT contained in the dielectric film 15 have a perovskite-type structure, when the laminated structure 10 has a conductive film 14, the dielectric film 15 made of PZT can be easily epitaxially grown on the conductive film 13 compared to when the laminated structure 10 does not have a conductive film 14.

[0024] As mentioned above, in the technology described in Patent Document 1, when a PZT film thicker than 30 nm is formed by a coating method, the PZT film becomes less likely to be oriented (100) in a pseudocubic crystal representation, for example, and the piezoelectric properties of the piezoelectric film cannot be improved.

[0025] Furthermore, when forming a PZT film thicker than 30 nm by vapor deposition rather than coating, it is necessary to form the PZT film under a vacuum atmosphere at a high temperature, for example, around 400°C or higher, in order to orient the PZT film to (100) in pseudocubic crystal representation. Therefore, if the piezoelectric film contains an element with a high vapor pressure, such as Pb, the deficiency of that element may reduce its insulating properties and degrade its piezoelectric properties.

[0026] Furthermore, the techniques described in Patent Document 2 and Patent Document 3 describe a technique in which a film is deposited in an amorphous state on an electrode made of Pt, and then heat-treated by RTA to crystallize the PLZT film and PZT film, i.e., the PZT film. However, simply depositing a dielectric film in an amorphous state on an electrode made of Pt does not allow the crystallized PZT film to be (100) oriented in a pseudocubic crystal representation.

[0027] On the other hand, in the laminated structure of this embodiment 1, the buffer film 12 includes a first portion PR1 and a second portion PR2 different from the first portion PR1. The first portion PR1 consists of a metal oxide MX11 containing one or more metal elements selected from the group consisting of Group 4 elements other than Hf, and the second portion PR2 consists of a metal oxide MX12 containing Hf. The metal oxide MX11 has a cubic crystal structure and is (100) oriented, and the metal oxide MX12 has a cubic crystal structure and is (100) oriented. Furthermore, the dielectric film 15 consists of a metal oxide MX21 as PZT, and the metal oxide MX21 has a cubic crystal structure and is (100) oriented.

[0028] In other words, the inventors have found that the buffer film 12 consists of two types of parts, each with a different Zr / Hf ratio and a different crystal structure, and that these two types of parts and PZT undergo epitaxial growth on the substrate 11 to have a cubic crystal structure. This is thought to be because the metal oxide containing Hf, such as hafnium oxide (HfO2), contained in the buffer film 12 undergoes martensitic transformation, and when a dielectric film 15 is formed on the buffer film 12, twinning deformation occurs in the buffer film 12 due to the martensitic transformation, causing dynamic lattice matching to occur, in which atoms are rearranged within the buffer film 12 so that the lattice constant of the dielectric film 15 matches the lattice constant of the substrate 11 via the buffer film 12.

[0029] The laminated structure of this embodiment 1 can be manufactured by the manufacturing method of the laminated structure of embodiment 2, which will be described later. Therefore, compared to the technologies described in the above-mentioned Patent Documents 1 to 3, even when forming a dielectric film containing elements with high vapor pressure and a thick film thickness on a substrate, the TAT can be shortened, the orientation of the dielectric film can be easily controlled, defects of elements with high vapor pressure can be prevented or suppressed, and the insulating properties of the dielectric film can be improved.

[0030] Furthermore, even if PZT has a tetragonal crystal structure, if it becomes (100) oriented, i.e., a-axis oriented, the piezoelectric properties will decrease. On the other hand, since the metal oxide MX21 as PZT has a cubic crystal structure and is (100) oriented, the risk of a-axis orientation and a decrease in piezoelectric properties is reduced compared to when PZT has a tetragonal crystal structure, and thus the piezoelectric properties of the dielectric film 15 can be improved.

[0031] As shown in Figure 1, when the laminated structure 10 of this embodiment 1 has a conductive film 16 formed on a dielectric film 15, the laminated structure of this embodiment 1 can be applied to a piezoelectric actuator by using the dielectric film 15 as a piezoelectric film, the conductive films 13 and 14 as lower electrodes, and the conductive film 16 formed on the dielectric film 15 as an upper electrode. On the other hand, when applying the laminated structure of this embodiment 1 to a surface acoustic wave (SAW) device instead of a piezoelectric actuator, for example, the dielectric film 15 can be formed directly on the buffer film 12 without the conductive films 13 and 14 in between.

[0032] Preferably, the first portion PR1 consists of a metal oxide MX11 containing one or more metal elements selected from the group consisting of Group 4 elements other than Hf, and one or more metal elements selected from the group consisting of Nb, Ta, Si, rare earth elements, Al, and Group 2 elements. The second portion PR2 consists of a metal oxide MX12 containing Hf and one or more metal elements selected from the group consisting of Nb, Ta, Si, rare earth elements, Al, and Group 2 elements. Here, the one or more metal elements selected from the group consisting of Nb, Ta, Si, rare earth elements, Al, and Group 2 elements are stabilizers that stabilize zirconium oxide (ZrO2) and hafnium oxide (HfO2).

[0033] Since metal oxide MX11 contains one or more metal elements selected from the group consisting of Group 4 elements other than Hf, and metal oxide MX12 contains Hf, when the buffer film 12 is deposited in the temperature range RG1 shown in Figure 9 later, metal oxide MX11 tends to have a cubic crystal structure and metal oxide MX12 tends to have a tetragonal crystal structure. On the other hand, if both metal oxide MX11 and metal oxide MX12 contain the above-mentioned stabilizer, even when the buffer film 12 is deposited in the temperature range RG1, it is easy to control so that both metal oxide MX11 and metal oxide MX12 have a cubic crystal structure, and it is possible to prevent or suppress fluctuations in their crystal structure depending on the temperature conditions when depositing the dielectric film 15.

[0034] <Method for manufacturing laminated structures> Next, the manufacturing method of the laminated structure of Embodiment 1 will be described. Figures 4 to 8 are cross-sectional views of the manufacturing process of the laminated structure of Embodiment 1. Figure 9 is a schematic diagram showing the relationship between the film deposition temperature and crystal structure of ZrO2 and HfO2.

[0035] First, as shown in Figure 4, a substrate 11 is prepared (step S1). In step S1, a substrate 11 is prepared, for example, a silicon substrate made of a silicon (Si) single crystal. Next, as shown in Figure 4, an epitaxially grown buffer film (first film) 12 is formed on the substrate 11 (step S2). In this step S2, a buffer film 12 made of a first metal compound containing Hf is formed.

[0036] Next, as shown in Figure 5, an epitaxially grown conductive film 13 is formed on the buffer film 12 (step S3). In step S3, for example, a conductive film 13 is formed from a platinum group element such as Pt, which has a cubic crystal structure and is (100) oriented. Next, as shown in Figure 6, an epitaxially grown conductive film 14 is formed on the conductive film 13 (step S4). In step S4, for example, a conductive film 14 is formed containing strontium ruthenate (SrRuO3) which is (100) oriented in a pseudocubic crystal representation.

[0037] Next, as shown in Figures 7 and 8, an epitaxially grown dielectric film 15 is formed on the conductive film 14 (step S5). In this step S5, a dielectric film 15 (see Figure 8) is formed from a metal oxide MX21 (see Figure 8) having a perovskite-type structure or an ilmenite-type structure. As the dielectric film 15 having a perovskite-type structure, for example, PZT, lead lanthanum zirconate titanate ((Pb,La)(Zr,Ti)O3):PLZT, barium strontium titanate ((Ba,Sr)TiO3:BST), potassium sodium niobate ((K,Na)NbO3:KNN), potassium sodium tantalate ((K,Na)TaO3:KNT), lithium niobate (LiNbO3:LN), and lithium tantalate (LiTaO3:LT) can be used.

[0038] In step S5, first, as shown in Figure 7, a dielectric film 15a made of amorphous metal oxide MX22 is formed on the buffer film 12 by sputtering, i.e., by vapor deposition, at a second temperature lower than the first temperature at which metal oxide MX21 (see Figure 8) crystallizes, but at which metal oxide MX21 does not crystallize (step S6).

[0039] Furthermore, in step S5, after step S6, the dielectric film 15a is heat-treated at a first temperature to form a dielectric film 15 consisting of a crystallized metal oxide MX21, as shown in Figure 8 (step S7). That is, step S5 includes steps S6 and S7. For example, if the metal oxide MX21 is PZT, the first temperature can be, for example, 500 to 750°C, and the second temperature can be 50 to 300°C.

[0040] Next, a conductive film 16 made of a platinum group element such as Pt is formed on the dielectric film 15 to form the laminated structure 10 of this embodiment 1, as shown in Figure 1 (step S8).

[0041] In the manufacturing method of the laminated structure of this embodiment 1, step S4 is not required, and the conductive film 14 is not required to be formed on the conductive film 13. However, since both the metal oxide contained in the conductive film 14 and the metal oxide contained in the dielectric film 15 have a perovskite-type structure, etc., in the manufacturing method of the laminated structure of this embodiment 1, when step S4 is performed, the dielectric film 15 can be easily epitaxially grown on the conductive film 13 compared to when step S4 is not performed.

[0042] As mentioned above, in the technology described in Patent Document 1, when a PZT film thicker than 30 nm is formed by a coating method, the PZT film becomes less likely to be oriented (100) in a pseudocubic crystal representation, for example, and the piezoelectric properties of the piezoelectric film cannot be improved.

[0043] Furthermore, when forming a PZT film thicker than 30 nm by vapor deposition rather than coating, it is necessary to form the PZT film under a vacuum atmosphere at a high temperature, for example, around 400°C or higher, in order to orient the PZT film to (100) in pseudocubic crystal representation. Therefore, if the piezoelectric film contains an element with a high vapor pressure, such as Pb, the deficiency of that element may reduce its insulating properties and degrade its piezoelectric properties.

[0044] Furthermore, the techniques described in Patent Document 2 and Patent Document 3 describe a technique in which a film is deposited in an amorphous state on an electrode made of Pt, and then heat-treated by RTA to crystallize the PLZT film and PZT film, i.e., the PZT film. However, simply depositing a dielectric film in an amorphous state on an electrode made of Pt does not allow the crystallized PZT film to be (100) oriented in a pseudocubic crystal representation.

[0045] On the other hand, in the manufacturing method of the laminated structure of this embodiment 1, step S2 is performed to form a buffer film 12 made of a metal compound containing Hf and grown epitaxially. Step S5 also includes steps S6 and S7, in which step S6 is performed to form a dielectric film 15a made of amorphous metal oxide MX22 on the buffer film 12 made of a metal compound containing Hf and grown epitaxially by sputtering at a second temperature lower than the first temperature at which metal oxide MX21 crystallizes and at which metal oxide MX21 does not crystallize, and in step S7 is performed to form a dielectric film 15 made of metal oxide MX21 in which metal oxide MX22 has crystallized by heat treatment of the dielectric film 15a at the first temperature.

[0046] In other words, the inventors have found that by forming a dielectric film 15a on an epitaxially grown buffer film 12 made of a metal compound containing Hf at a temperature at which the dielectric film 15 does not crystallize, and then heat-treating the formed dielectric film 15a at a temperature at which it crystallizes, the crystallized dielectric film 15 undergoes epitaxial growth. This is thought to be because the metal compound containing Hf, such as hafnium oxide (HfO2), contained in the buffer film 12 is a material that undergoes martensitic transformation, and when the dielectric film 15a is heat-treated at the first temperature, twinning deformation occurs in the buffer film 12 along with the martensitic transformation, causing dynamic lattice matching to occur, in which atoms are rearranged inside the buffer film 12 so that the lattice constant of the dielectric film 15 matches the lattice constant of the substrate 11 via the buffer film 12.

[0047] In other words, according to the manufacturing method of the laminated structure of this embodiment 1, an amorphous dielectric film 15a is formed on a buffer film 12 made of a martensitically transforming metal compound by vapor deposition at a low temperature, and then the dielectric film 15a is crystallized by heat treatment at a high temperature. Therefore, even when forming a dielectric film 15 containing elements with high vapor pressure and a thick film thickness on a substrate 11, the orientation of the dielectric film 15 can be easily controlled while shortening the turnaround time (TAT), preventing or suppressing defects in elements with high vapor pressure, and improving the insulating properties of the dielectric film 15.

[0048] As explained using Figure 1 above, in the manufacturing method of the laminated structure 10 of this embodiment 1, when step S8 is performed to form a conductive film 16 on the dielectric film 15, the laminated structure of this embodiment 1 can be applied to a piezoelectric actuator by using the dielectric film 15 as a piezoelectric film, the conductive films 13 and 14 as lower electrodes, and the conductive film 16 formed on the dielectric film 15 as an upper electrode. On the other hand, when applying the laminated structure of this embodiment 1 to, for example, a SAW device, after step S2, steps S3 and S4 are omitted, and step S5 is performed, thereby forming the dielectric film 15 directly on the buffer film 12 without the conductive films 13 and 14 in between.

[0049] Preferably, in step S1, a substrate 11 is prepared, comprising a Si(100) substrate 11 including a main surface 11p made of a Si(100) plane, as shown in Figure 4, or an SOI substrate comprising a base body 11a made of a Si substrate, an insulating layer 11b on the base body 11a, and an SOI layer 11c made of a Si(100) film on the insulating layer 11b including a main surface 11p made of a Si(100) plane, as shown in Figure 2. In step S2, a buffer film (first film) 12 is formed on the main surface 11p, comprising a metal oxide MX13 containing Hf and one or more metal elements selected from the group consisting of Group 4 elements other than Hf, and oriented to (100) in a pseudocubic crystal representation, or a metal nitride MX31 containing Hf and one or more metal elements selected from the group consisting of Group 4 elements other than Hf, and oriented to (100) in a pseudocubic crystal representation.

[0050] When the buffer film (first film) 12 contains a metal oxide MX13, any one or more metal elements selected from the group consisting of Hf and other Group 4 elements other than Hf are more easily oxidized than Si. Therefore, in step S2, the buffer film 12, which is made of a metal oxide MX13 of a metal that is more easily oxidized than Si, can be epitaxially grown on the main surface 11p in a direction aligned with the orientation direction of Si on the main surface 11p which is made of a Si(100) plane.

[0051] Furthermore, the epitaxial growth of the buffer film 12, which is made of metal oxide MX13, on the main surface 11p is thought to be due to a crystal growth mechanism in which, for example, the dynamic lattice matching effect due to the twinning martensitic transformation exhibited by the metal oxide MX13, which is the main component of the buffer film 12 and consists of HfO2, (Hf,Zr)O2, or ZrO2, acts as a driving force, propulsion, or driving force when the conductive film 13, conductive film 14, and dielectric film 15 grow epitaxially. However, the theory is not necessarily limited to this.

[0052] Preferably, in step S3, a conductive film 13 made of a platinum group element such as Pt having a cubic crystal structure and being (100) oriented is formed, as shown in Figure 5. In such a case, the conductive film 13 made of a platinum group element such as Pt can be epitaxially grown on the buffer film 12 in a direction aligned with the orientation direction of the buffer film 12.

[0053] Preferably, in step S7, as shown in Figure 8, a dielectric film 15 made of a metal oxide MX21 oriented (100) in pseudocubic form is formed on the conductive film 13. In such a case, if the dielectric film 15 is a piezoelectric film, the dielectric film 15 can be oriented (100) in pseudocubic form so that the polarization direction is perpendicular to the main surface 11p, thereby improving the piezoelectric properties of the dielectric film 15.

[0054] Preferably, in step S7, a dielectric film 15 is formed consisting of a metal oxide MX21 represented by the following compositional formula (Chemical Formula 3), as shown in Figure 8. Pb(Zr 1-x Ti x )O3...(C3) In the above compositional formula (Chemical Formula 3), x satisfies 0 ≤ x ≤ 1. Note that the above compositional formula (Chemical Formula 3) is the same compositional formula as the above compositional formula (Chemical Formula 1). In such a case, in step S7, a dielectric film 15 made of PZT, which has a large piezoelectric constant and excellent piezoelectric properties, can be grown on the main surface 11p.

[0055] Preferably, in step S7, as shown in FIG. 8, a dielectric film 15 made of a metal oxide MX21 having a cubic crystal structure and oriented (100) is formed. In such a case, compared with the case where PZT has a tetragonal crystal structure, the risk of a-axis orientation and deterioration of piezoelectric characteristics is reduced, and conversely, the piezoelectric characteristics of the dielectric film 15 can be improved.

[0056] Preferably, in step S2, as shown in FIG. 4, a buffer film 12 including a first portion PR1 and a second portion PR2 different from the first portion PR1 is formed. The first portion PR1 is made of a metal oxide MX11 containing one or more metal elements selected from the group consisting of group 4 elements other than Hf, and the second portion PR2 is made of a metal oxide MX12 containing Hf.

[0057] In such a case, by adjusting the temperature conditions and pressure conditions when forming the buffer film 12, both the metal oxide MX11 and the metal oxide MX12 can have a cubic crystal structure, both the metal oxide MX11 and the metal oxide MX12 can have a tetragonal crystal structure, or one of the metal oxide MX11 and the metal oxide MX12 can have a cubic crystal structure and the other can have a tetragonal crystal structure. Therefore, even when forming the buffer film 12 in a vacuum film forming apparatus, it is possible to prevent or suppress the variation of the crystal structure depending on the temperature conditions and the like during film formation, and stably form the buffer film 12 having the same crystal structure. Also, even when forming a conductor film 13 (see FIG. 5) made of a platinum group element such as Pt on the buffer film 12, it is possible to stably form the conductor film 13 having the same orientation direction and film quality.

[0058] Here, preferred examples of the metal oxides MX11 and MX12 are shown in Table 1. Table 1 shows preferred examples of the metal oxides MX11 and MX12 and the values of the standard Gibbs free energy (kJmol -1 ) of each metal oxide, which are the values described in Non-Patent Document 1.

[0059] [Table 1]

[0060] Including HfO2 and ZrO2, the standard Gibbs free energy (GIB) values ​​for metal oxides MX11 and MX12 shown in Table 1 are lower than the standard Gibbs free energy for SiO2. In such cases, the metal elements contained in each of the metal oxides MX11 and MX12 reduce the SiO2 on the Si substrate and oxidize themselves, allowing each of the metal oxides MX11 and MX12 to grow directly on the Si substrate without an intervening SiO2 film.

[0061] Preferably, the first portion PR1 consists of a metal oxide MX11 containing one or more metal elements selected from the group consisting of Group 4 elements other than Hf, and one or more metal elements selected from the group consisting of Nb, Ta, Si, rare earth elements, Al, and Group 2 elements. The second portion PR2 consists of a metal oxide MX12 containing Hf and one or more metal elements selected from the group consisting of Nb, Ta, Si, rare earth elements, Al, and Group 2 elements.

[0062] Since metal oxide MX11 contains one or more metal elements selected from the group consisting of Group 4 elements other than Hf, and metal oxide MX12 contains Hf, when the buffer film 12 is deposited in the temperature range RG1 shown in Figure 9 later, metal oxide MX11 tends to have a cubic crystal structure and metal oxide MX12 tends to have a tetragonal crystal structure. On the other hand, if both metal oxide MX11 and metal oxide MX12 contain the above-mentioned stabilizer, even when the buffer film 12 is deposited in the temperature range RG1, it is easy to control so that both metal oxide MX11 and metal oxide MX12 have a cubic crystal structure, and it is possible to prevent or suppress fluctuations in their crystal structure depending on the temperature conditions when depositing the dielectric film 15.

[0063] Preferably, in step S7, as shown in Figure 8, the dielectric film 15 is formed with the metal oxide MX11 having a cubic crystal structure and being (100) oriented, and the metal oxide MX12 having a cubic crystal structure and being (100) oriented.

[0064] In such cases, a dielectric film 15 made of PZT having a cubic crystal structure and being (100) oriented can be easily formed on a first portion PR1 made of metal oxide MX11 having a cubic crystal structure and being (100) oriented. Similarly, a dielectric film 15 made of PZT having a cubic crystal structure and being (100) oriented can be easily formed on a second portion PR2 made of metal oxide MX12 having a cubic crystal structure and being (100) oriented.

[0065] Preferably, in step S2, a buffer film 12 is formed, as shown in Figure 4, comprising a first portion PR1 consisting of a metal oxide MX11 having a cubic crystal structure and being (100) oriented, and a second portion PR2 consisting of a metal oxide MX12 having a tetragonal crystal structure and being (001) oriented.

[0066] As shown in Figure 9, the inventors have found that when the buffer film is made of HfO2, the temperature ranges for depositing metal oxides with a monoclinic crystal structure, metal oxides with a tetragonal crystal structure, and metal oxides with a cubic crystal structure are all higher than when the buffer film is made of ZrO2.

[0067] Therefore, when the buffer film 12 is formed in the temperature range RG1 shown in Figure 9, metal oxide MX11 having a Zr / Hf ratio greater than that of metal oxide MX12 can have a cubic crystal structure, and metal oxide MX12 having a Zr / Hf ratio smaller than that of metal oxide MX11 can have a tetragonal crystal structure.

[0068] In this way, because the buffer film 12 has two parts, a first part PR1 and a second part PR2, each having a different Zr / Hf ratio, it is possible to prevent or suppress fluctuations in its crystal structure due to temperature conditions during film formation, and to stably form a buffer film 12 with the same crystal structure.

[0069] Preferably, in step S6, as shown in Figure 7, the dielectric film 15a is formed with the metal oxide MX11 having a tetragonal crystal structure and being (001) oriented, and the metal oxide MX12 having a cubic crystal structure and being (100) oriented.

[0070] As mentioned above, in step S2, metal oxide MX11, which has a Zr / Hf ratio greater than that of metal oxide MX12, has a cubic crystal structure, and metal oxide MX12, which has a Zr / Hf ratio smaller than that of metal oxide MX11, has a tetragonal crystal structure. However, in step S6, at the second temperature in which metal oxide MX21 does not crystallize, when a dielectric film 15a consisting of amorphous metal oxide MX22 is formed by vapor deposition, it is thought that a martensitic transformation occurs in metal oxide MX11 and metal oxide MX12, resulting in metal oxide MX11 having a tetragonal crystal structure and metal oxide MX12 having a cubic crystal structure.

[0071] Furthermore, as will be explained later using Figure 21, after forming the dielectric film 15a and before heat treatment of the dielectric film 15a, the lattice constants of the metal oxide MX11(ZrO2) having a tetragonal crystal structure in the direction along the main surface 11p and in the direction perpendicular to the main surface 11p are shorter than the lattice constants of the metal oxide MX12(HfO2) having a tetragonal crystal structure in the direction along the main surface 11p and in the direction perpendicular to the main surface 11p, respectively, before forming the dielectric film 15a. Also, after forming the dielectric film 15a and before heat treatment of the dielectric film 15a, the lattice constants of the metal oxide MX12(HfO2) having a cubic crystal structure in the direction along the main surface 11p and in the direction perpendicular to the main surface 11p are shorter than the lattice constants of the metal oxide MX11(ZrO2) having a cubic crystal structure in the direction along the main surface 11p and in the direction perpendicular to the main surface 11p, respectively, before forming the dielectric film 15a. As a result, the dielectric film 15a will have tensile stress.

[0072] Preferably, in step S7, the dielectric film 15a is heat-treated at a temperature higher than the second temperature and lower than the third temperature between the first and second temperatures (step S9). In step S9, the dielectric film 15a is heat-treated at a temperature higher than the second temperature and lower than the third temperature so that the metal oxide MX11 has a cubic crystal structure and is (100) oriented, and the metal oxide MX12 has a tetragonal crystal structure and is (001) oriented.

[0073] In this case, a temperature higher than the second temperature and lower than the third temperature is close to the second temperature, which is the temperature at which the dielectric film 15a was formed. Therefore, similar to step S2, the dielectric film 15a is heat-treated with the metal oxide MX11 having a cubic crystal structure and (100) orientation, and the metal oxide MX12 having a tetragonal crystal structure and (001) orientation.

[0074] Preferably, in step S7, along the main surface 11p of the metal oxide MX21 <100> The direction is aligned with the main surface 11p, which is the Si(100) surface of the substrate 11. <110> A dielectric film 15 is formed from oriented metal oxide MX21 so as to be parallel to the direction. That is, the PZT crystal lattice of the dielectric film 15 is aligned with the Si crystal lattice of the substrate 11, rotated by 45° around a rotation axis perpendicular to the main plane 11p relative to the Si crystal lattice of the substrate 11.

[0075] When a dielectric film 15 is formed on a buffer film 12 by vapor deposition at a first temperature at which metal oxide MX21 crystallizes, the PZT crystal lattice of the dielectric film 15 aligns with the Si crystal lattice of the substrate 11 without being rotated 45° around a rotation axis perpendicular to the main plane 11p relative to the Si crystal lattice of the substrate 11. Therefore, it can be seen that the dielectric film 15 made of PZT is formed by first forming a dielectric film 15a made of amorphous metal oxide MX22 by vapor deposition at a second temperature at which metal oxide MX21 does not crystallize, and then heat-treating the dielectric film 15a at the first temperature to form the dielectric film 15 made of metal oxide MX21.

[0076] Preferably, the first temperature is 500 to 750°C, and the second temperature is 50 to 300°C. When the first temperature is 500°C or higher, the dielectric film 15a can be crystallized more easily compared to when the first temperature is less than 500°C. Also, when the first temperature is 750°C or lower, even when forming a dielectric film 15 containing elements with high vapor pressure on the substrate 11, it is possible to prevent or suppress the deficiency of elements with high vapor pressure, compared to when the first temperature is greater than 750°C. Also, when the second temperature is 50°C or higher, it is easier to control the temperature during the formation of the dielectric film 15a to be constant compared to when the second temperature is less than 50°C. Also, when the second temperature is 300°C or lower, the temperature of the substrate 11 during the formation of the dielectric film 15a is lower compared to when the second temperature is greater than 300°C, so the energy consumption required to form the dielectric film 15a can be reduced.

[0077] Preferably, in step S7, the dielectric film 15a is heated from room temperature to a first temperature at a heating rate of 5 to 200°C / second, and then heat-treated at the first temperature. When the heating rate is 5°C / second or higher, the temperature of the substrate 11 can be raised from room temperature to the maximum temperature in a shorter time compared to when the heating rate is less than 5°C / second. Therefore, even if an undesirable phase exists in any temperature range between room temperature and the maximum temperature, the appearance of that undesirable phase can be prevented or suppressed. Also, when the heating rate is 200°C / second or lower, the amount of energy required to form the dielectric film 15a can be reduced compared to when the heating rate exceeds 200°C / second.

[0078] Preferably, the third temperature is the temperature at which the metal oxide MX11 has a cubic crystal structure and is (100) oriented, and the metal oxide MX12 has a tetragonal crystal structure and is (001) oriented. In such a case, in step S7, the dielectric film 15a can be heat-treated in the same manner as in step S2, with the metal oxide MX11 having a cubic crystal structure and being (100) oriented, and the metal oxide MX12 having a tetragonal crystal structure and being (001) oriented.

[0079] (Embodiment 2) Next, an electronic device of Embodiment 2, which is one embodiment of the present invention, will be described. The electronic device of Embodiment 2 is an inkjet print head as a fluid discharge device, equipped with the laminated structure of Embodiment 1. Figure 10 is a cross-sectional view of the electronic device of Embodiment 2.

[0080] As shown in Figure 10, the electronic device 20 of this second embodiment is an electronic device comprising the laminated structure 10 of the first embodiment, which has a substrate 11, a buffer film 12, a conductive film 13, a conductive film 14, a dielectric film 15, and a conductive film 16. The electronic device 20 of this second embodiment is a piezoelectric actuator in which the conductive films 13 and 14 function as lower electrodes and the conductive film 16 functions as an upper electrode.

[0081] Furthermore, the electronic device 20 of this second embodiment includes a chamber 23 for containing fluid. The chamber 23 is configured to take in fluid from a tank (not shown) via a flow path 24.

[0082] A buffer film 12 is formed on a substrate 11 made of a Si substrate, and the buffer film 12 faces the chamber 23. By using a buffer film 12 made of HfO2, (Hf,Zr)O2(HZO), or ZrO2 as the dielectric layer, adhesion to the Si substrate and crystallinity are superior compared to cases where SiO2 or SiN is used as the dielectric layer, and furthermore, piezoelectric properties and durability are also superior.

[0083] The electronic device 20 of this second embodiment further includes an insulating film 25, a conductive path 26, and a passivation film 27.

[0084] The material constituting the insulating film 25 is not particularly limited, but dielectric materials such as SiO2, SiN, or Al2O3 can be used as the material constituting the insulating film 25. Furthermore, although the thickness of the insulating film 25 is not particularly limited, it is preferably between approximately 10 nm and approximately 10 μm.

[0085] The conductive path 26 is formed on the insulating film 25 and is electrically connected to the lower electrode, which consists of the conductive film 13 and the conductive film 14, and the upper electrode, which consists of the conductive film 16, respectively, enabling selective access when using the electronic device 20. The material constituting the conductive path 26 is not particularly limited, but conductive materials such as aluminum (Al) can be used as the material constituting the conductive path 26.

[0086] The passivation film 27 is formed on the insulating film 25, on the lower electrode consisting of the conductive film 13 and the conductive film 14, on the upper electrode consisting of the conductive film 16, and on the conductive path 26. The passivation film 27 functions as a barrier layer that protects the piezoelectric element from humidity and other elements. The material constituting the passivation film 27 is not particularly limited, but dielectric materials such as SiN or SION (silicon oxynitrate) can be used as the material constituting the passivation film 27. The thickness of the passivation film 27 is not particularly limited, but it is preferably between approximately 0.1 μm and approximately 3 μm. Similarly, the conductive pad 28 is provided along the piezoelectric actuator and is electrically connected to the conductive path 26.

[0087] In the electronic device of this second embodiment, similar to the stacked structure of the first embodiment, the buffer film 12 includes a first portion PR1 and a second portion PR2 different from the first portion PR1. The first portion PR1 consists of a metal oxide MX11 containing one or more metal elements selected from the group consisting of Group 4 elements other than Hf, and the second portion PR2 consists of a metal oxide MX12 containing Hf. The metal oxide MX11 has a cubic crystal structure and is (100) oriented, and the metal oxide MX12 has a cubic crystal structure and is (100) oriented. The dielectric film 15 consists of a metal oxide MX21 as PZT, and the metal oxide MX21 has a cubic crystal structure and is (100) oriented.

[0088] In such cases, compared to the technologies described in Patent Documents 1 to 3 above, even when forming a dielectric film containing elements with high vapor pressure and a thick film thickness on a substrate, the orientation of the dielectric film can be easily controlled while shortening the turnaround time (TAT), preventing or suppressing defects of elements with high vapor pressure, and improving the insulating properties of the dielectric film. Furthermore, compared to the case where PZT has a tetragonal crystal structure, the risk of a-axis orientation and a decrease in piezoelectric properties is reduced, thus actually improving the piezoelectric properties of the dielectric film 15. As a result, the electrical properties of the piezoelectric actuator can be improved.

[0089] As mentioned above, the laminated structure 10 provided in the electronic device 20 of this embodiment 2 can also use a semiconductor substrate, such as an SOI substrate, instead of a Si substrate as the substrate 11, similar to the laminated structure 10 of embodiment 1. Furthermore, the electronic device equipped with the laminated structure is not limited to piezoelectric actuators, but can include various electronic devices such as FBARs (Film Bulk Acoustic Resonators). [Examples]

[0090] The present invention will be described in more detail below based on examples, but the present invention is not limited to the following examples.

[0091] (Example 1) [Formation of laminated structures] A laminated structure of Example 1 was fabricated. First, the crystal growth surface of the Si(100) substrate 11 (see Figure 4) was treated with reactive ion etching (RIE), and after heating in the presence of oxygen to form a thermal oxide film, a single crystal film of metal oxide, serving as buffer film 12 (see Figure 4), was formed on the Si substrate by molecular beam epitaxy (MBE) without the use of oxygen, causing a thermal reaction between the metal (Hf, Zr) of the deposition source and the oxygen in the oxide film on the Si substrate. Next, the single crystal film of metal oxide, serving as buffer film 12 (see Figure 4), was deposited by MBE by flowing oxygen, lowering the temperature, and increasing the pressure. The conditions for the MBE method during this deposition were as follows. The target values ​​for Hf:Zr:Y (atomic ratio, the same applies below) were 22.5:67.5:10. Vapor deposition source: Hf, Zr, Y Voltage: 3.5~4.75V Pressure: 3 × 10 -2 ~6×10 -2 Pa Substrate temperature: 450~700℃

[0092] Next, a Pt metal film was formed as a conductive film 13 on a single-crystal metal oxide film, which served as a buffer film 12, by sputtering. The conditions for this process are shown below. Equipment: ULVAC QAM-4 sputtering system Pressure: 1.20 × 10 -1 Pa Target: Pt Power: 100W(DC) Thickness: 80nm Substrate temperature: 450~600℃

[0093] Next, a conductive film 14, consisting of an SRO film, was formed on a Pt metal film, which served as the conductive film 13, by sputtering. The conditions for this process are shown below. Equipment: ULVAC QAM-4 sputtering system Power: 150W (RF) Gas: Ar Pressure: 1.8 Pa Substrate temperature: 600℃ Thickness: 10nm

[0094] Next, an amorphous film made of amorphous PZT was formed as a dielectric film 15a on the conductive film 14 made of SRO film by sputtering. The conditions for this process are shown below. Equipment: RF magnetron sputtering apparatus Power: 350W Gas: Ar / O2 (Flow rate ratio of Ar to O2 = 19:1) Pressure: 4.5 Pa Target: 0.8[Pb(Zr 0.53 Ti 0.47 )O3]+20mol%PbO Substrate temperature: 300℃ Thickness: 100nm

[0095] Next, the dielectric film 15a was heat-treated using an RTA (Rapid Thermal Annealing) apparatus to form a dielectric film 15 in which amorphous PZT crystallized. The conditions used for this process are shown below. Equipment: RTA equipment Setting temperature: 650~700℃ Set heating rate: 10°C / second Maximum temperature: 700℃

[0096] In this manner, the laminated structure of Example 1 was fabricated by sequentially forming the buffer film 12, the conductive film 13, the conductive film 14, and the dielectric film 15. As mentioned above, the conductive film 14 may not be formed between the conductive film 13 and the dielectric film 15, and the dielectric film 15 may be formed on the conductive film 13 without the conductive film 14 in between.

[0097] [X-ray diffraction measurement] After forming a buffer film 12, a conductive film 13, and a conductive film 14 on the main surface 11p of the substrate 11, and before forming the dielectric film 15, the diffraction pattern of the laminated structure was measured by X-ray diffraction (XRD) measurement using the θ-2θ method, with the laminated structure positioned so that the diffraction plane in the X-ray diffraction (XRD) measurement was parallel to the main surface 11p. The diffraction pattern of the laminated structure of Example 1 measured is shown in Figure 11. The XRD measurement was performed using a Rigaku SmartLab X-ray diffractometer.

[0098] As shown in Figure 11, diffraction peaks were observed in the diffraction pattern for the (200) plane of cubic ZrO2 (denoted as YHZO c(002) in Figure 11) and the (400) plane of cubic ZrO2 (denoted as YHZO c(004) in Figure 11). Furthermore, diffraction peaks were observed in the diffraction pattern for the (002) plane of tetragonal HfO2 (denoted as YHZO t(002) in Figure 11) and the (004) plane of tetragonal HfO2 (denoted as YHZO t(004) in Figure 11). Therefore, it was revealed that the metal oxide MX11 contained in the first part PR1 has a cubic crystal structure and is (100) oriented, and the metal oxide MX12 contained in the second part PR2 has a tetragonal crystal structure and is (001) oriented.

[0099] Furthermore, as shown in Figure 11, strong diffraction peaks were observed in the diffraction pattern at the (002) plane of Pt and the (001) plane of SrRuO3 (denoted as SRO(001) in Figure 11). Therefore, it became clear that the conductive film 13 is made of Pt having a cubic crystal structure and (100) orientation, and the conductive film 14 is made of SrRuO3 oriented (100) in a pseudocubic crystal representation.

[0100] Furthermore, with the stacked structure positioned so that the diffraction plane in the X-ray diffraction measurement is tilted at 90° with respect to the main plane 11p (in-plane measurement), a φ scan was performed on the cubic (200) plane (2θ=35°) of ZrO2 contained in the metal oxide MX11 contained in the first part PR1, or on the tetragonal (110) plane (2θ=35°) of HfO2 contained in the metal oxide MX12 contained in the second part PR2. The φ scan measured for the stacked structure of Example 1 is shown in Figure 12.

[0101] As shown in Figure 12, in the φ scan, four strong diffraction peaks were observed at 90° intervals, representing either the (200) plane of cubic ZrO2 (denoted as YHZO c(200) in Figure 12) or the (110) plane of tetragonal HfO2 (denoted as YHZO t(110) in Figure 12). In other words, in the φ scan, diffraction peaks showing four-fold symmetry of the buffer film 12 were observed. Therefore, it became clear that the metal oxide MX11 contained in the first portion PR1 had its crystal axis aligned in the in-plane direction along the main surface 11p of the substrate 11, i.e., it underwent epitaxial growth, and that the metal oxide MX12 contained in the second portion PR2 also had its crystal axis aligned in the in-plane direction along the main surface 11p of the substrate 11, i.e., it underwent epitaxial growth.

[0102] Although not shown in the diagram, four diffraction peaks were also observed at 90° intervals on the (400) plane (2θ=69°) of Si, and the angles of Φ of the four diffraction peaks were approximately equal to the angles of the four diffraction peaks shown in Figure 12. Therefore, metal oxides MX11 and MX12 are shown in the pseudocubic representation along the main plane 11p of metal oxides MX11 and MX12. <100> The direction is aligned with the main surface 11p, which is the Si(100) surface of the substrate 11. <100> It became clear that the orientation was parallel to the direction.

[0103] Furthermore, after forming the dielectric film 15a and before heat treatment, the diffraction pattern of the laminated structure was measured by X-ray diffraction measurement using the θ-2θ method, with the laminated structure positioned so that the diffraction plane in the X-ray diffraction measurement was parallel to the main surface 11p. The measured diffraction pattern of the laminated structure of Example 1 is shown in Figure 13.

[0104] As shown in Figure 13, strong diffraction peaks were observed in the diffraction pattern of the (002) plane of tetragonal ZrO2 (denoted as YHZO t(002) in Figure 13) and the (004) plane of tetragonal ZrO2 (denoted as YHZO t(004) in Figure 13). In addition, strong diffraction peaks were observed in the diffraction pattern of the (200) plane of cubic HfO2 (denoted as YHZO c(002) in Figure 11) and the (400) plane of cubic HfO2 (denoted as YHZO c(004) in Figure 11). Therefore, it was revealed that the metal oxide MX11 contained in the first part PR1 has a tetragonal crystal structure and is (001) oriented, and the metal oxide MX12 contained in the second part PR2 has a cubic crystal structure and is (100) oriented.

[0105] Furthermore, after forming the dielectric film 15 by heat treatment of the dielectric film 15a, the diffraction pattern of the laminated structure was measured by X-ray diffraction measurement using the θ-2θ method, with the laminated structure positioned so that the diffraction plane in the X-ray diffraction measurement was parallel to the main surface 11p. The measured diffraction pattern of the laminated structure of Example 1 is shown in Figure 14.

[0106] As shown in Figure 14, strong diffraction peaks were observed in the diffraction pattern for the (200) plane of cubic ZrO2 and HfO2 (denoted as YHZO c(002) in Figure 14) and the (400) plane of cubic ZrO2 and HfO2 (denoted as YHZO c(004) in Figure 14). On the other hand, weak diffraction peaks were observed in the diffraction pattern for the (002) plane of tetragonal ZrO2 and HfO2 (denoted as YHZO t(002) in Figure 14) and the (004) plane of tetragonal ZrO2 and HfO2 (denoted as YHZO t(004) in Figure 14). Therefore, it was revealed that the metal oxide MX11 contained in the first part PR1 has a cubic crystal structure and is (100) oriented, and the metal oxide MX12 contained in the second part PR2 has a cubic crystal structure and is (100) oriented.

[0107] Furthermore, as shown in Figure 14, diffraction peaks were observed in the diffraction pattern of the (100) plane of cubic PZT (denoted as PZT(001) in Figure 14) and the (200) plane of cubic PZT (denoted as PZT(002) in Figure 14). Therefore, it was revealed that the dielectric film 15 has a cubic crystal structure and is (100) oriented.

[0108] Furthermore, with the stacked structure positioned so that the diffraction plane in the X-ray diffraction measurement is tilted at 90° with respect to the main plane 11p (in-plane measurement), a φ scan was performed on the cubic (110) plane (2θ=31°) of PZT contained in the metal oxide MX21 contained in the dielectric film 15. Figure 15 shows the φ scan measured for the stacked structure of Example 1.

[0109] As shown in Figure 15, in the φ scan, four strong diffraction peaks on the (110) plane of the cubic PZT were observed at 90° intervals. That is, in the φ scan, diffraction peaks showing four-fold symmetry of the dielectric film 15 were observed. Therefore, it became clear that the crystal axes of the metal oxide MX21 contained in the dielectric film 15 are aligned in the in-plane direction along the main surface 11p of the substrate 11, i.e., that it has grown epitaxially.

[0110] Although not shown in the diagram, four diffraction peaks were also observed at 90° intervals on the (400) plane (2θ=69°) of Si, and the angle of Φ of the four diffraction peaks was shifted by 45° from the angle of the four diffraction peaks shown in Figure 15. Therefore, along the main surface 11p of the metal oxide MX21, <100> The direction is aligned with the main surface 11p, which is the Si(100) surface of the substrate 11. <110> It became clear that the orientation was parallel to the direction.

[0111] (Example 2) [Formation of laminated structures] The laminated structure of Example 2 was fabricated in the same manner as in Example 1, except that an amorphous film made of amorphous PZT was formed as the dielectric film 15a, and the dielectric film 15a was not heat-treated using an RTA apparatus.

[0112] [High-temperature X-ray diffraction measurement] After forming a buffer film 12, a conductive film 13, a conductive film 14, and a dielectric film 15a on the main surface 11p of the substrate 11, the dielectric film 15a was heat-treated. The laminated structure was positioned so that the diffraction plane in the X-ray diffraction measurement using the θ-2θ method was parallel to the main surface 11p. The temperature of the substrate 11 was raised from room temperature to 750°C, and then the diffraction pattern of the laminated structure was measured by X-ray diffraction while the temperature of the substrate 11 was lowered from 750°C back to room temperature. In other words, high-temperature X-ray diffraction measurement was performed. The diffraction pattern of the laminated structure of Example 2 measured is shown in Figure 16. Furthermore, the temperature dependence of the c-axis length of cubic ZrO2 or HfO2 calculated from Figure 16 is shown in Figure 17, the temperature dependence of the c-axis length of tetragonal ZrO2 or HfO2 calculated from Figure 16 is shown in Figure 18, and the temperature dependence of the c-axis length of PZT calculated from Figure 16 is shown in Figure 19.

[0113] As shown in Figures 16 and 17, as the temperature increased, the (200) peak (indicated as c(002) in Figure 17) of the cubic ZrO2 or HfO2 was observed even at temperatures below 450°C, and the (200) peak of the cubic ZrO2 or HfO2 was also observed at temperatures above 500°C. On the other hand, as shown in Figures 16 and 18, as the temperature increased, the (002) peak (indicated as t(002) in Figure 18) of the tetragonal ZrO2 or HfO2 was observed at temperatures below 450°C, but the (002) peak of the tetragonal ZrO2 or HfO2 was not observed at temperatures above 500°C. Furthermore, as shown in Figures 16 and 19, when the temperature increased, the (200) peak of the cubic PZT was not observed at temperatures below 450°C, but the (200) peak of the cubic PZT (labeled as PZT(002) in Figure 19) was observed at temperatures above 500°C. Therefore, it became clear that amorphous PZT crystallizes at temperatures above 500°C, and that the tetragonal peaks of ZrO2 or HfO2 disappear with the crystallization of PZT.

[0114] [Crystal structure of PZT amorphous film during heat treatment] Similarly, the diffraction pattern of the laminated structure was measured by X-ray diffraction with the laminated structure positioned so that the diffraction plane in the X-ray diffraction measurement was tilted at 90° with respect to the main plane 11p (in-plane measurement). The diffraction pattern of the laminated structure of Example 2 measured is shown in Figure 20. In addition, the time variation of temperature in Example 2, and the lattice constants of ZrO2, HfO2, and PZT in the direction along the main plane 11p (denoted as the a-axis length in Figure 21) and in the direction perpendicular to the main plane 11p (denoted as the c-axis length in Figure 21), as well as the crystal structure, which were calculated from the results in Figures 16 and 20 for each temperature range, were identified. The results are shown in Figure 21.

[0115] As shown in Figure 21, after forming the buffer film 12, the conductive film 13, and the conductive film 14 on the substrate 11, and before forming the dielectric film 15a, the metal oxide MX11 (denoted as ZrO2 in Figure 21) contained in the first portion PR1 had a cubic crystal structure and was (100) oriented, and the metal oxide MX12 (denoted as HfO2 in Figure 21) contained in the second portion PR2 had a tetragonal crystal structure and was (001) oriented.

[0116] Furthermore, after forming the dielectric film 15a on the substrate 11 and before heat treatment of the dielectric film 15a, the metal oxide MX11 (denoted as ZrO2 in Figure 21) contained in the first portion PR1 had a tetragonal crystal structure and was (001) oriented, and the metal oxide MX12 (denoted as HfO2 in Figure 21) contained in the second portion PR2 had a cubic crystal structure and was (100) oriented.

[0117] Here, after forming the dielectric film 15a and before heat treatment of the dielectric film 15a, the lattice constant in the direction along the main plane 11p in the region having a cubic crystal structure and (100) orientation (denoted as the a-axis length in Figure 21), and the lattice constant in the direction perpendicular to the main plane 11p in the region having a cubic crystal structure and (100) orientation (denoted as the c-axis length in Figure 21), were both shorter than before forming the dielectric film 15a. Furthermore, after forming the dielectric film 15a and before heat treatment of the dielectric film 15a, the lattice constant in the direction along the main plane 11p in the region having a tetragonal crystal structure and (001) orientation (denoted as the a-axis length in Figure 21), and the lattice constant in the direction perpendicular to the main plane 11p in the region having a tetragonal crystal structure and (001) orientation (denoted as the c-axis length in Figure 21), were both shorter than before forming the dielectric film 15a.

[0118] As a result, when the ratio (molar ratio) of the first portion PR1 to the buffer film 12 is relatively close to the ratio (molar ratio) of the second portion PR2 to the buffer film 12, for example, Hf:Zr = 22.5:67.5 to 67.5:22.5, the buffer film 12 shrinks in the direction along the main surface 11p, and the dielectric film 15a, which is made of amorphous metal oxide MX22, has tensile stress.

[0119] Furthermore, after the heat treatment of the dielectric film 15a was started, while the heat treatment was being performed at a temperature higher than the second temperature (300°C) at which the dielectric film 15a was formed, and lower than the third temperature (500°C) between the first temperature (750°C) and the second temperature, the metal oxide MX11 (denoted as ZrO2 in Figure 21) contained in the first portion PR1 had a cubic crystal structure and was (100) oriented, and the metal oxide MX12 (denoted as HfO2 in Figure 21) contained in the second portion PR2 had a tetragonal crystal structure and was (001) oriented.

[0120] Furthermore, when the substrate 11 was heat-treated at a temperature higher than the third temperature (500°C), the metal oxide MX11 (indicated as ZrO2 in Figure 21) contained in the first portion PR1 had a cubic crystal structure and was (100) oriented, and the metal oxide MX12 (indicated as HfO2 in Figure 21) contained in the second portion PR2 also had a cubic crystal structure and was (100) oriented.

[0121] Although a detailed explanation is omitted, the same results as in Examples 1 and 2, where the Hf:Zr ratio was 22.5:67.5, were obtained even when the Hf:Zr ratio was other than 22.5:67.5.

[0122] Furthermore, although a detailed explanation will be omitted, when a buffer film 12 containing a metal nitride MX31 made of HfN, HZN, or ZrN was used instead of a buffer film 12 containing a metal oxide MX13 made of HfO2, HZO, or ZrO2, the same results as those obtained in Examples 1 and 2 were obtained when the buffer film 12 contained a metal oxide MX13 made of HfO2, HZO, or ZrO2. [Explanation of symbols]

[0123] 10 Laminated Structure 11 circuit boards 11a Base 11b Insulating layer 11c SOI layer 11p main surface 12 Buffer membrane 13, 14, 16 Conductive film 15, 15a Dielectric film 20 Electronic Devices 23 Chambers 24 channels 25 Insulator film 26 Conductive Path 27 Passivation membrane 28 conductive pads MX11, MX12, MX13, MX21, MX22 metal oxides MX31 Metal Nitride PR1 Part 1 PR2 Part 2 RG1 Temperature Range UC1, UC2 unit cell

Claims

1. (a) Steps to prepare the substrate, (b) A step of forming an epitaxially grown first film on the substrate, (c) A step of forming a first dielectric film epitaxially grown on the first film, In a method for manufacturing a laminated structure having, In step (b) above, the first film is formed, which is made of a first metal compound containing Hf. In step (c) above, the first dielectric film is formed, which is made of a first metal oxide having a perovskite-type structure or an ilmenite-type structure. The above step (c) is, (c1) A step of forming a second dielectric film on the first film by vapor deposition, at a second temperature lower than the first temperature at which the first metal oxide crystallizes and at which the first metal oxide does not crystallize. (c2) After step (c1), heat-treat the second dielectric film at a first temperature to form the first dielectric film which is made of the first metal oxide in which the second metal oxide has crystallized. A method for manufacturing a laminated structure, including [the specified element].

2. In the method for manufacturing a laminated structure according to claim 1, (d) A step of forming an epitaxially grown first conductive film on the first film, It has, In step (c), the first dielectric film is formed on the first conductive film. A method for manufacturing a laminated structure, wherein step (c1) involves forming the second dielectric film on the first conductive film.

3. In the method for manufacturing a laminated structure according to claim 2, In step (a) above, a substrate is prepared, which is a Si(100) substrate including a main surface made of a Si(100) plane, or an SOI substrate including a base made of a Si substrate, an insulating layer on the base, and an SOI layer on the insulating layer that is made of a Si(100) film and includes the main surface made of a Si(100) plane. In step (b) above, a first film is formed on the main surface, comprising a third metal oxide containing Hf and one or more metal elements selected from the group consisting of Group 4 elements other than Hf, and oriented at (100) in a pseudocubic crystal representation, or a first metal nitride containing Hf and one or more metal elements selected from the group consisting of Group 4 elements other than Hf, and oriented at (100) in a pseudocubic crystal representation. In step (d) above, the first conductive film is formed, which has a cubic crystal structure and is made of (100)-oriented platinum group elements. A method for manufacturing a laminated structure, wherein the (c2) step involves forming the first dielectric film made of the first metal oxide oriented (100) in a pseudocubic crystal representation.

4. In the method for manufacturing a laminated structure according to claim 3, In step (c2) above, the first dielectric film is formed, which is made of the first metal oxide represented by the following compositional formula (Chemical Formula 1). Pb(Zr １－ｘ Ti ｘ )O ３ ...(Formula 1) The method for manufacturing a laminated structure, wherein x satisfies 0 ≤ x ≤ 1.

5. In the method for manufacturing a laminated structure according to claim 4, A method for manufacturing a laminated structure, wherein the (c2) step involves forming the first dielectric film made of the first metal oxide having a cubic crystal structure and being (100) oriented.

6. In the method for manufacturing a laminated structure according to claim 5, In step (b) above, the first film is formed, which includes a first portion and a second portion different from the first portion. The first part comprises a fourth metal oxide containing one or more metal elements selected from the group consisting of elements other than Hf. The second part relates to a method for manufacturing a laminated structure made of a fifth metal oxide containing Hf.

7. In the method for manufacturing a laminated structure according to claim 6, The first portion comprises the fourth metal oxide, which includes one or more metallic elements selected from the group consisting of Group 4 elements other than Hf, and one or more metallic elements selected from the group consisting of Nb, Ta, Si, rare earth elements, Al, and Group 2 elements. The second part is a method for manufacturing a laminated structure, comprising the fifth metal oxide containing Hf and one or more metal elements selected from the group consisting of Nb, Ta, Si, rare earth elements, Al, and group 2 elements.

8. In the method for manufacturing a laminated structure according to claim 6 or 7, A method for manufacturing a laminated structure, wherein in step (c2), the fourth metal oxide has a cubic crystal structure and is (100) oriented, and the fifth metal oxide has a cubic crystal structure and is (100) oriented, and the first dielectric film is formed in this state.

9. In the method for manufacturing a laminated structure according to claim 8, A method for manufacturing a laminated structure, wherein step (b) above is to form the first film comprising the fourth metal oxide having a cubic crystal structure and being (100) oriented, and the fifth metal oxide having a tetragonal crystal structure and being (001) oriented.

10. In the method for manufacturing a laminated structure according to claim 9, A method for manufacturing a laminated structure, wherein in step (c1), the second dielectric film is formed with the fourth metal oxide having a tetragonal crystal structure and being (001) oriented, and the fifth metal oxide having a cubic crystal structure and being (100) oriented.

11. In the method for manufacturing a laminated structure according to claim 10, The (c2) step is, (c3) A step of heat-treating the second dielectric film at a temperature higher than the second temperature and lower than a third temperature between the first temperature and the second temperature. Includes, A method for manufacturing a laminated structure, wherein in step (c3), the second dielectric film is heat-treated while the fourth metal oxide has a cubic crystal structure and is (100) oriented, and the fifth metal oxide has a tetragonal crystal structure and is (001) oriented.

12. In the method for manufacturing a laminated structure according to claim 5, A method for manufacturing a laminated structure, wherein in step (c2), the first dielectric film is formed of the first metal oxide oriented such that the <100> direction along the main surface of the first metal oxide is parallel to the <110> direction along the main surface which is the Si(100) surface of the substrate.

13. In a method for manufacturing a laminated structure according to any one of claims 1 to 5, The first temperature is 500 to 750°C. A method for manufacturing a laminated structure, wherein the second temperature is 50 to 300°C.

14. In a method for manufacturing a laminated structure according to any one of claims 1 to 5, In step (c2), the second dielectric film is heated from room temperature to the first temperature at a heating rate of 5 to 200°C / second, and then heat-treated at the first temperature. A method for manufacturing a laminated structure, including [the specified element].

15. In the method for manufacturing a laminated structure according to claim 11, A method for manufacturing a laminated structure, wherein the third temperature is the temperature at which the fourth metal oxide has a cubic crystal structure and is (100) oriented, and the fifth metal oxide has a tetragonal crystal structure and is (001) oriented.

16. A substrate including the main surface, A first film epitaxially grown on the main surface, A first conductive film epitaxially grown on the first film, A first dielectric film epitaxially grown on the first conductive film, In a laminated structure having, The substrate is a Si(100) substrate including the main surface which is made of a Si(100) plane, or an SOI substrate including a substrate made of a Si substrate, an insulating layer on the substrate, and an SOI layer on the insulating layer which is made of a Si(100) film and includes the main surface which is made of a Si(100) plane. The first conductive film has a cubic crystal structure and is composed of (100)-oriented platinum group elements. The first film is Part 1 and, A second part that differs from the first part mentioned above, Includes, The first part comprises a first metal oxide containing one or more metal elements selected from the group consisting of Group 4 elements other than Hf. The second portion consists of a second metal oxide containing Hf, The first metal oxide has a cubic crystal structure and is (100) oriented, The second metal oxide has a cubic crystal structure and is (100) oriented. The first dielectric film consists of a third metal oxide represented by the following compositional formula (Chemical Formula 1), Pb(Zr １－ｘ Ti ｘ )O ３ ...(Formula 1) The above x satisfies 0 ≤ x ≤ 1, The third metal oxide is a laminated structure having a cubic crystal structure and being (100) oriented.

17. In the laminated structure according to claim 16, The first portion comprises the first metal oxide, which includes one or more metallic elements selected from the group consisting of Group 4 elements other than Hf, and one or more metallic elements selected from the group consisting of Nb, Ta, Si, rare earth elements, Al, and Group 2 elements. The second portion is a laminated structure comprising the second metal oxide, which includes Hf and one or more metal elements selected from the group consisting of Nb, Ta, Si, rare earth elements, Al, and group 2 elements.

18. An electronic device comprising the laminated structure according to claim 16 or 17.

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