TECHNICAL FIELD [0001] The present invention relates to a method for manufacturing a PNbZT thin film used in a thin-film piezoelectric device of a thin-film capacitor, or the like. Priority is claimed on Japanese Patent Application No. 2013-175100, filed 10 August 27, 2013 and Japanese Patent Application No. 2014-171180, filed August 26, 2014, the contents of which are incorporated herein by reference. BACKGROUND ART [0002] 15 It is known that piezoelectric characteristics are enhanced by adding Nb to a PZT thin film expressed by the composition formula PbzZrxTii_x03 formed by a sol-gel method (for example, refer to NPL 1). In this paper, an effect of Nb doping on a (lOO)-textured PZT thin film grown on a PbTiC>3 seeding layer prepared by a chemical solution deposition (CSD) method was investigated. Specifically, an effect of Nb 20 doping in the range of 0 at% to 4 at% on 1 |am thick (lOO)-textured Pb1.1Zro.52Tio.48O3 thin film was investigated. Texturing of (100) as high as 97% is obtained for all the films due to the incorporation of a thin Pbi.osTi03 seeding layer having a thickness of several nanometers. Overall, the maximum polarization, remanent polarization, squareness, and coercivity of the PZT thin film decrease with the Nb doping level. The 25 PZT thin film doped with 3% Nb shows the maximum effective piezoelectric coefficient 2 -e3i,f of 12.9 C/cm2, which is 5% to 15% higher than those of thin films with other doping levels. DOCUMENTS OF RELATED ART 5 NON-PATENT LITERATURE [0003] [NPL 1] Jian Zhong et al., "Effect of Nb Doping on Highly {100}-Textured PZT Films Grown on CSD-Prepared PbTi03 Seed Layers", Integrated Ferroelectrics 130(2011)1-11 10 DISCLOSURE OF INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION [0004] However, in the technique for enhancing the piezoelectric characteristics of the 15 PZT thin film by the addition of Nb described in NPL 1 according to the related art, when the PZT thin film (PNbZT thin film) doped with Nb is formed by a wet type method, that is, a chemical solution deposition (CSD) method using a sol-gel solution, concentration gradients of Zr and Ti in a film thickness direction occur during each baking, and thus there is a problem in that the piezoelectric characteristics and the like of the PNbZT thin 20 film are degraded. [0005] An object of the present invention is to provide a method for manufacturing a PNbZT thin film, in which each composition in the film is substantially uniform and higher piezoelectric characteristics and dielectric characteristics can be obtained. 25 MEANS TO SOLVE THE PROBLEMS 3 [0006] The inventors found that: when a coating film formed on a substrate using a sol-gel solution that satisfies the composition formula PbzNbxZryTii_y03 is calcined and the calcined film is baked, a Zr element is less likely to be crystallized compared to a Ti 5 element, the Zr element and the Ti element are thus segregated; and the behavior of segregation regarding an Nb element is not discovered, there is still room for improvement in piezoelectric characteristics and the like, and the inventors accomplished the present invention. [0007] 10 A first aspect of the present invention is a method for manufacturing a PNbZT thin film including: a process of preparing a plurality of types of sol-gel solutions having different concentration ratios of zirconium and titanium (Zr/Ti) while satisfying the composition formula PbzNbxZryTii.y03 (02 film 14 provided on the substrate body 13, and a lower electrode 15 provided on the SiC>2 film 14. The lower electrode 15 is formed of a material that have conductivity caused by Pt, TiOx, Ir, Ru, or the like and does not react with a PNbZT thin film 11. For example, the lower electrode 15 may have a two-layer structure including a TiOx film 15a and a Pt film 15b in this order from the substrate 20 body 12 side. Specific examples of the TiOx film 15a include a TiC>2 film. Furthermore, the SiC^ film 14 is formed to enhance adhesion. In addition, in the substrate 12, it is preferable that a ferroelectric thin film formed of a complex perovskite film made of lead zirconate titanate (PZT), which does not contain Nb, be formed on the Pt film 15b of the lower electrode 15 as a crystallization acceleration layer 16 to a 25 predetermined film thickness. As a composition material used for forming the 8 crystallization acceleration layer 16, a PZT precursor as the raw material for forming a complex metal oxide having a perovskite structure is preferably contained in a proportion such that desired metal atomic ratios are achieved. Specifically, it is preferable that the PZT precursor be contained in a proportion that achieves metal atomic ratios in which A 5 in the composition formula PbAZri.BTiB03 satisfies 1.0 As a sol-gel solution for forming a PNbZT thin film, a sol-gel solution (an El solution manufactured by Mitsubishi Materials Corporation) in which the metal composition ratio was 125/10/52/48 (Pb/Nb/Zr/Ti) and the concentration (the sum of a Pb source, an Nb source, a Zr source, and a Ti source) of a precursor diluted using 1-butanol 25 as a solvent was adjusted to 15 mass% in terms of oxide amount was prepared. Here, 18 the reason that the ratio of Nb was set to be significantly higher than the upper limit of Nb expressed in the composition formula PbzNbxZryTii_y03 (02 film was formed on a silicon 5 substrate body having a diameter of 100 mm, a lower electrode including a TiOx film and a Pt film was formed on the SiC>2 film, and a crystallization acceleration layer was formed on the Pt film. In addition, in Comparative Example 1 and in Examples 1 to 7 and Comparative Examples 2 to 6 described below, unless otherwise specified, a (lOO)-textured PZT thin 10 film was formed on a Pt film as the crystallization acceleration layer and thereafter a PNbZT film was formed on the crystallization acceleration layer. In addition, as a composition for forming a PZT ferroelectric thin film to form the crystallization acceleration layer, a PZT sol-gel solution (trade name: PZT-E1 manufactured by Mitsubishi Materials Corporation) in which the metal composition ratio was 115/53/47 15 (Pb/Zr/Ti) and the concentration (the sum of a Pb source, a Zr source, and a Ti source) of a precursor diluted using 1-butanol as a solvent was adjusted to 12 mass% in terms of oxide amount was prepared. First, the prepared PZT sol-gel solution was dropped onto the Pt (lower electrode) of the Pt/TiCVSiCVSi substrate in which the crystal plane is preferentially textured in the (111) axis direction, and the resultant was subjected to spin 20 coating at a rotational speed of 3000 rpm for 15 seconds, thereby forming a coating film (gel film) on the substrate. Thereafter, the coating film formed on the substrate was calcined by being held at a temperature of 300°C in an air atmosphere for 5 minutes using a hot plate. In addition, the processes from the application of the composition to the calcination were repeated three times. Thereafter, baking was performed by 25 increasing the temperature from room temperature to 700°C at a temperature rising rate 19 of 10°C/s in an oxygen atmosphere through a rapid thermal annealing (RTA) process and holding the temperature for 1 minute. Accordingly, the crystallization acceleration layer formed of the PZT dielectric thin film having a film thickness of 60 nm and (lOO)-textured crystal orientation was formed. 5 [0039] Next, the substrate was set on a spin coater so that the crystallization acceleration layer was positioned at the upper surface, and while rotating the substrate at a rotational speed of 3000 rpm, the sol-gel solution was dropped onto the crystallization acceleration layer of the substrate for 15 seconds, thereby forming a coating film (gel 10 film) on the crystallization acceleration layer of the substrate. Next, the substrate on which the coating film was formed was calcined by being held at a temperature of 300°C for 5 minutes on the hot plate and was thereafter calcined by being held at a temperature of 450°C for 5 minutes, thereby calcining the coating film. By repeating the processes from the application of the sol-gel solution to the calcination three times, three layers of 15 calcined films were formed on the crystallization acceleration layer of the substrate. Furthermore, the substrate on which the calcined films were formed was baked by being held at 700°C for 1 minute in the oxygen atmosphere through the rapid thermal annealing (RTA) process. The temperature rising rate at this time was 10 °C/s. Accordingly, a single PNbZT thin film having a thickness of 240 nm was formed on the Pr film of the 20 substrate. The process of forming the PNbZT thin film, in which the processes from the application of the sol-gel solution to the calcination were repeated three times and the baking was thereafter performed once, was repeated four times, thereby forming a PNbZT thin film having four layers with a total thickness of about 1 |am on the crystallization acceleration layer of the substrate. The substrate on which the PNbZT 20 thin film was formed was used in Comparative Example 1. [0040] The PNbZT thin film formed on the substrate of Comparative Example 1 was 5 subjected to composition analysis by an energy-dispersive X-ray spectrometer (TEM-EDS) which uses a transmission electron microscope. Specifically, the PNbZT thin film was processed to a thickness of 50 nm by a focused ion beam (FIB), and thereafter the PNbZT thin film having a thickness of 50 nm was subjected to composition analysis for each component in a sectional direction of the PNbZT thin film by the 10 TEM-EDS apparatus. [0041] As a result, the concentration of Zr in the PNbZT thin film was high in the film upper portion (the opposite side of the crystallization acceleration layer) and was gradually decreased toward the film lower portion (the side coming into contact with the 15 crystallization acceleration layer). In addition, contrary to the concentration of Zr, the concentration of Ti in the PNbZT thin film was low in the film lower portion (the opposite side of the crystallization acceleration layer) and was gradually increased toward the film lower portion (the side coming into contact with the crystallization acceleration layer). On the other hand, the concentration of Nb in the PNbZT thin film 20 is substantially uniform at any point in the film and segregation thereof was not seen. The above description implies that in a CSD method, in order to form a PNbZT thin film (a PZT film containing Nb added thereto) having high characteristics, it is important to eliminate composition unevenness after baking by laminating coating films (gel films) with composition ratios of Zr and Ti, which are changed in a stepwise manner, during 25 film formation and thereafter baking the resultant. 21 [0042] As a sol-gel solution for forming a PNbZT thin film, a first sol-gel solution (an El solution manufactured by Mitsubishi Materials Corporation) in which the metal 5 composition ratio was 116/1/60/40 (Pb/Nb/Zr/Ti) and the concentration (the sum of a Pb source, an Nb source, a Zr source, and a Ti source) of a precursor diluted using 1-butanol as a solvent was adjusted to 10 mass% in terms of oxide amount was prepared. In a similar manner, a second sol-gel solution in which the metal composition ratio was 116/1/54/46 (Pb/Nb/Zr/Ti), a third sol-gel solution in which the metal composition ratio 10 was 116/1/52/48 (Pb/Nb/Zr/Ti), a fourth sol-gel solution in which the metal composition ratio was 116/1/50/50 (Pb/Nb/Zr/Ti), and a fifth sol-gel solution in which the metal composition ratio was 116/1/44/56 (Pb/Nb/Zr/Ti) were prepared. Furthermore, the same substrate as in Comparative Example 1 was prepared. In addition, the first to fifth sol-gel solutions were prepared using the El solution manufactured by Mitsubishi 15 Materials Corporation. [0043] First, the substrate was set on a spin coater so that the crystallization acceleration layer was positioned at the upper surface, and while rotating the substrate at a rotational speed of 3000 rpm, the first sol-gel solution was dropped onto the 20 crystallization acceleration layer of the substrate for 15 seconds, thereby forming a coating film (gel film) on the crystallization acceleration layer of the substrate. The substrate on which the coating film was formed was calcined by being held at a temperature of 300°C for 5 minutes on a hot plate and was thereafter calcined by being held at a temperature of 450°C for 5 minutes, thereby calcining the coating film and 25 forming a first calcined film. Next, by changing the first sol-gel solution to the second 22 sol-gel solution, in the same manner, a second calcined film was formed on the first calcined film by performing the application of the second sol-gel solution and calcination in two stages. In addition, by changing the second sol-gel solution to the third sol-gel solution, in the same manner, a third calcined film was formed on the second calcined 5 film by performing the application of the third sol-gel solution and calcination in two stages. Next, by changing the third sol-gel solution to the fourth sol-gel solution, in the same manner, a fourth calcined film was formed on the third calcined film by performing the application of the fourth sol-gel solution and calcination in two stages. In addition, by changing the fourth sol-gel solution to the fifth sol-gel solution, in the same manner, a 10 fifth calcined film was formed on the fourth calcined film by performing the application of the fifth sol-gel solution and calcination in two stages. As described above, five layers including the first to fifth calcined films each of which has a thickness of 50 nm were formed on the crystallization acceleration layer of the substrate. Furthermore, the substrate on which the first to fifth calcined films were formed was baked under the same 15 conditions as those of Comparative Example 1. Accordingly, a single PNbZT thin film having a thickness of 250 nm was formed on the crystallization acceleration layer of the substrate. The process of forming the PNbZT thin film, in which the processes from the application of the first to fifth sol-gel solutions to the calcination were repeated five times and the baking was thereafter performed once, was repeated four times, thereby forming 20 a PNbZT thin film having four layers with a total thickness of about 1 |am (about 1000 nm) on the crystallization acceleration layer of the substrate. The substrate on which the PNbZT thin film was formed was used in Example 1. [0044] 25 A PNbZT thin film was formed on the crystallization acceleration layer of the 23 substrate in the same manner as in Example 1 except that, by repeating the process of forming the PNbZT thin film eight times, in which the processes from the application of the first to fifth sol-gel solutions to the calcination were repeated five times and the baking was performed once, the PNbZT thin film having eight layers with a total 5 thickness of about 2 |am (about 2000 nm) was formed on the crystallization acceleration layer of the substrate. The substrate on which the PNbZT thin film was formed was used in Example 2. [0045] 10 A PNbZT thin film was formed in the same manner as in Example 1 except that the concentrations of the sol-gel solutions, the number of times of application of the coating films for each baking process, the film thickness of one layer, the film thicknesses after the baking, the concentration ratio of Pt/Nb, the concentration ratio Zr/Ti for each coating film, the number of times of baking processes of the PNbZT thin 15 film, and the film thickness of the PNbZT thin film (hereinafter, referred to as various conditions) were changed as shown in Tables 1 and 2. The substrate on which the PNbZT thin film was formed was used in Examples 3, 4, and 7. In addition, in Examples 3, 4, and 7, only three types including the first to third 20 sol-gel solutions were prepared, the first to third coating films were formed using the respective sol-gel solutions, and thereafter the resultant was baked. This point is the same in the following examples, and a plurality of sol-gel solutions shown in Tables 1 and 2 were used, and coating films corresponding thereto were formed. [0046] 25 24 A PNbZT thin film was formed in the same manner as in Example 1 except that the various conditions were changed as shown in Tables 1 and 2. The substrate on which the PNbZT thin film was formed was used in Examples 5 and 6. In addition, in Examples 5 and 6, the first and second sol-gel solutions were 5 synthesized by the following method. Lead acetate trihydrate, titanium tetraisopropoxide, zirconium (iv) tetrabutoxide, niobium pentaethoxide, acetyl acetone, and propylene glycol were weighed so as to allow the metal composition ratio Pb/Nb/Zr/Ti to achieve the above-mentioned ratio, and were then injected into a reaction container and circulated while being held at 150°C for 1 hour in a nitrogen atmosphere. 10 The circulated mixed liquid was subjected to distillation under reduced pressure to remove unreacted substances from the mixed liquid. In addition, after the inside of the reaction container was cooled to room temperature, water was added thereto and the resultant was circulated while being held at 150°C for 1 hour in the nitrogen atmosphere, and the inside of the reaction container was cooled to room temperature again. 15 Thereafter, 2.5 mol% of polyvinylpyrrolidone (PVP) was added to PZT in terms of monomer amount, and the resultant was stirred at room temperature for 24 hours. The stirred mixed liquid was diluted with ethanol, thereby obtaining 25 mass% of the first and second sol-gel solutions (PNbZT solutions) in terms of the amount of oxides. [0047] 20 A PNbZT thin film was formed in the same manner as in Example 1 except that the various conditions were changed as shown in Tables 1 and 2. The substrate on which the PNbZT thin film was formed was used in Comparative Examples 2, 3, 5, and 6. 25 A single sol-gel solution was used in Comparative Examples 2 and 3, first to 25 fifth coating films were formed in Comparative Example 2, and first to third coating films were formed in Comparative Example 3. The Nb content of a sol-gel solution of Comparative Example 5 was high, and a sol-gel solution of Comparative Example 6 did not contain Nb. 5 [0048] A PNbZT thin film was formed in the same manner as in Example 5 except that the various conditions were changed as shown in Tables 1 and 2. The substrate on which the PNbZT thin film was formed was used in Comparative Example 4. 10 In Comparative Example 4, a single sol-gel solution was used, and first and second coating films were formed. [0049] The PNbZT thin film formed on the substrate of Examples 1 to 7 and 15 Comparative Examples 2 to 6 were subjected to composition analysis, permittivity measurement, and piezoelectric constant measurement. The composition analysis of the PNbZT thin film was performed by the energy-dispersive X-ray spectrometer (TEM-EDS) which uses a transmission electron microscope. Specifically, first, the PNbZT thin film was processed to one layer of the PNbZT thin film obtained in a single 20 baking process by a focused ion beam (FIB). That is, one layer of the PNbZT thin film was produced by being processed to a thickness of 50 nm in Examples 1 and 2 and Comparative Example 2, one layer of the PNbZT thin film was produced by being processed to a thickness of 84 nm in Examples 3 and 4 and Comparative Examples 3, 5, and 6, and one layer of the PNbZT thin film was produced by being processed to a 25 thickness of 200 nm in Examples 5 and 6 and Comparative Example 4. Next, the 26 PNbZT thin films were subjected to composition analysis for each component in a sectional direction of the PNbZT thin film by the TEM-EDS apparatus, and a percentage of a value which the difference between the amount of Zr in the vicinity of the uppermost portion and the amount of Zr in the vicinity of the lowermost portion of the PNbZT thin 5 film obtained in a single baking process was divided by the amount of Zr in the vicinity of the lowermost portion was calculated as a variation of Zr in the film thickness direction. [0050] The permittivity measurement was performed using a ferroelectric evaluation 10 apparatus (TF-analyzer2000 manufactured by aixACCT Systems). Specifically, an electrode of 200 |am(|) was formed on each of both surfaces of the PNbZT thin film by a sputtering method, and the resultant was thereafter held at 700°C for 1 minute in an oxygen atmosphere through a rapid thermal annealing (RTA) process, and was subjected to annealing to recover damage, thereby producing a thin-film condenser. The 15 permittivity of the thin-film condenser as a test sample was measured by the ferroelectric evaluation apparatus. To obtain a non-dimensional value, the measured permittivity was divided by the permittivity in a vacuum, thereby calculating a relative permittivity. The relative permittivity is a value including the crystallization acceleration layer in addition to the PNbZT thin film. 20 [0051] The piezoelectric constant measurement was performed using a piezoelectric evaluation apparatus (aixPES manufactured by aixACCT Systems). Specifically, first, the PNbZT thin film was processed to a strip shape by a focused ion beam (FIB). Thereafter the PNbZT thin film formed in the strip shape was subjected to a polarization 25 process of holding at a temperature of 110°C for 1 minute in an electric field of 100 27 kV/cm. Furthermore, strain was applied to the PNbZT thin film subjected to the polarization process, and a charge amount generated was measured by the piezoelectric evaluation apparatus, thereby obtaining the piezoelectric constant e3i,f. The results are shown in Table 2. In Table 2, the concentrations of the sol-gel solutions, the number of 5 times of application of the coating films for each baking process, the film thickness of one layer, the film thicknesses after the baking, the presence or absence of concentration gradients of Zr/Ti, the number of times of baking processes of the PNbZT thin film, and the film thickness of the PNbZT thin film are also shown. In addition, in Table 1, in addition to the concentrations of the sol-gel solutions, the number of times of application 10 of the coating films after the baking, the film thickness of one layer, the film thicknesses after the baking, and the concentration ratio Pb/Nb, the concentration ratio Zr/Ti for each coating film is shown. [0052] [Table 1] 28 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Concentration of sol-gel solution (%) 10 10 15 15 25 25 15 10 15 25 15 15 Coating film (for each baking) Number of times of application (times) 5 5 3 3 2 2 3 5 3 2 3 3 Film thickness One layer [nm] 50 50 84 84 200 200 84 50 84 200 84 84 After baking (nm) 250 250 250 250 400 400 250 250 250 400 250 250 Concentration ratio Pb/Nb 116/1 116/1 120/5 120/5 116/1 116/1 120/5 116/1 116/1 116/1 121/6 115/0 Concentration ratio Zr/Ti First coating film 60/40 60/40 60/40 60/40 54/46 54/46 60/40 52/48 52/48 52/48 60/40 60/40 Second coating film 54/46 54/46 52/48 52/48 50/50 50/50 52/48 52/48 52/48 52/48 52/48 52/48 Third coating film 52/48 52/48 44/56 44/56 - - 44/56 52/48 52/48 - 44/56 44/56 Fourth coating film 50/50 50/50 - - - - - 52/48 - - - - Fifth coating film 44/56 44/56 - - - - - 52/48 - - - - 29 [0053] [Table 2] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Concentration of sol-gel solution (%) 10 10 15 15 25 25 15 10 15 25 15 15 Coating film (for each baking) Number of times of application (times) 5 5 3 3 2 2 3 5 3 2 3 3 Film thickness One layer [nm] 50 50 84 84 200 200 84 50 84 200 84 84 After baking (nm) 250 250 250 250 400 400 250 250 250 400 250 250 Presence or absence of concentration gradient of Zr/Ti for each coating film Present Present Present Present Present Present Present Absent Absent Absent Present Present PNbZT thin film Number of times of baking (times) 4 8 4 12 5 12 4 4 4 5 4 4 Film thickness (nm) 1000 2000 1000 3000 2000 4800 1000 1000 1000 2000 1000 1000 Variation of Zr in film thickness direction (%) 1.2 1.1 2.3 2.2 2.8 2.8 2.0 6.2 5.6 8.3 7.4 6.4 Relative permittivity 1980 2010 2300 1950 1810 1680 1930 1420 1500 1340 1930 1500 Piezoelectric constant e3i,f (C/m2) -19.3 -20.1 -18.4 -19.1 -17.5 -16.8 -18.9 -13.2 -14.1 -12.6 -13.4 -15.0 30 [0054] As is apparent from Table 2, in Comparative Examples 2 to 4 in which coating films including two layers, three layers, or five layers having the same concentration ratio Zr/Ti were laminated on the crystallization acceleration layer of the substrate, the 5 variation of Zr in the film thickness direction in one layer of the PNbZT thin film was as high as 5.6% to 8.3%. In contrast, in Examples 1 to 6 in which the coating films including two layers, three layers, or five layers were laminated on the crystallization acceleration layer of the substrate to allow the concentration ratio Zr/Ti to be decreased in a stepwise manner, the variation of Zr in the film thickness direction in one layer of the 10 PNbZT thin film was as low as 1.1% to 2.8%. That is, in Examples 1 to 6, each composition in the PNbZT thin film is substantially uniform. [0055] In addition, in Comparative Examples 2 to 4, the relative permittivity of the thin-film condenser was as low as 1340 to 1500. In contrast, in Examples 1 to 6, the 15 relative permittivity of the thin-film condenser was as high as 1680 to 2300. [0056] Furthermore, in Comparative Examples 2 to 4, the absolute value of the piezoelectric constant of the PNbZT thin film was as low as 12.6 C/m2to 14.1 C/m2. In contrast, in Examples 1 to 6, the absolute value of the piezoelectric constant of the 20 PNbZT thin film was as high as 16.8 C/m2 to 20.1 C/m2. Accordingly, in Examples 1 to 6, it was found that dielectric characteristics were enhanced. [0057] On the other hand, in Comparative Example 5 in which the coating films including three layers were laminated using the first to third sol-gel solutions having a 25 concentration ratio of Pb/Nb of 121/6 and thus having a high Nb content, the variation of 31 Zr in the film thickness direction in one layer of the PNbZT thin film was as high as 7.4. In Comparative Example 6 in which the coating films including three layers were laminated using the first to third sol-gel solutions having a concentration ratio of Pb/Nb of 115/0 and thus not containing Nb at all, the variation of Zr in the film thickness 5 direction in one layer of the PNbZT thin film was as high as 6.4. In contrast, in Examples 3 and 7 in which the coating films including three layers were laminated using the first to third sol-gel solutions having concentration ratio Pb/Nb of 120/5 and 116/1 and thus having appropriate Nb contents, the variation of Zr in the film thickness direction in one layer of the PNbZT thin film was as low as 2.3 and 2.0. Accordingly, it 10 was found that in Examples 3 and 7 in which Nb was contained in appropriate proportions, each composition in the PNbZT thin film is substantially uniform. [0058] In addition, in Comparative Example 6, the relative permittivity of the thin-film condenser was as low as 1500. In contrast, in Comparative Example 5, the relative 15 permittivity of the thin-film condenser was as high as 1930, and in Examples 3 and 7, the relative permittivity of the thin-film condenser was as high as 2300 and 1930. Accordingly, it was found that in Examples 3 and 7 in which Nb was contained in appropriate proportions and in Comparative Example 5 in which Nb was contained in a high proportion, dielectric characteristics were enhanced. 20 [0059] Moreover, in Comparative Example 5, the absolute value of the piezoelectric constant of the PNbZT thin film was as low as 13.4, and in Comparative Example 6, the absolute value of the piezoelectric constant of the PNbZT thin film was as low as 15.0. In contrast, in Examples 3 and 7, the absolute value of the piezoelectric constant of the 25 PNbZT thin film was as high as 18.4 and 18.9. Accordingly, it was found that in 32 Examples 3 and 7 in which Nb was contained in appropriate proportions, piezoelectric characteristics were enhanced. INDUSTRIAL APPLICABILITY 5 [0060] The method for manufacturing a PNbZT thin film of the present invention can be used for manufacturing of electronic components of a thin-film condenser, a thin film capacitor, an IPD, a condenser for a DRAM memory, a multi-layer condenser, the gate insulator of a transistor, a non-volatile memory, a pyroelectric infrared detecting element, 10 a piezoelectric element, an electro-optic element, a thin film actuator, a resonator, an ultrasonic motor, an electric switch, an optical switch, or an LC noise filter element. REFERENCE SIGNS LIST [0061] 15 11 PNbZT thin film 11a first calcined film l ib second calcined film l ie third calcined film 12 substrate 20 I/We Claim: 1. A method for manufacturing a PNbZT thin film includes: a process of preparing a plurality of types of sol-gel solutions having different 5 concentration ratio of zirconium and titanium (Zr/Ti) while satisfying the composition formula PbzNbxZryTii.y03 (0