Patent Description:
Conventionally, there has been proposed a device formed by stacking a plurality of piezoelectric films of different types. See <CIT> (Patent Reference <NUM>), for example.

However, a high-performance device including a plurality of piezoelectric films cannot be obtained when a plurality of piezoelectric films of different types are stacked on the same substrate in a conventional device.

<CIT> relates to a vibration power generation element for converting vibration energy into electric energy, and a vibration power generation device including the vibration power generation element.

<CIT> relates to a piezoelectric device, a piezoelectric transformer, and a method of manufacturing the piezoelectric device.

<CIT> relates to a laminate structure for a piezoelectric element in which a piezoelectric portion is provided on each of opposite surfaces of a vibration plate, a piezoelectric element, and a method of manufacturing a piezoelectric element.

<CIT> relates to a piezoelectric element used for an ultrasonic transmission / reception device, a piezoelectric transformer, and the like, and a manufacturing method thereof.

<CIT> relates to a semiconductor structure and a method for manufacturing the same, and an electronic device having the resonator assembly.

An object of the present disclosure is to provide a high-performance piezoelectric-body film joint substrate in which piezoelectric films of two or more types are provided in superimposition with each other on the same substrate and a manufacturing method thereof.

The present invention is defined in the independent claims <NUM> and <NUM>.

A method of manufacturing a piezoelectric-body film joint substrate in the present disclosure includes peeling off a first piezoelectric-body film formed on a first substrate and including a first piezoelectric film and a first electrode film provided on the first piezoelectric film and a second piezoelectric-body film formed on a second substrate and including a second piezoelectric film and a second electrode film provided on the second piezoelectric film respectively from the first substrate and the second substrate, sticking the first piezoelectric-body film on an electrode formed on a third substrate different from both of the first substrate and the second substrate, and sticking the second piezoelectric-body film on the first piezoelectric-body film.

According to the present disclosure, it is possible to provide a high-performance piezoelectric-body film joint substrate in which piezoelectric films of two or more types are provided in superimposition with each other on the same substrate and a manufacturing method thereof.

The present disclosure will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and wherein:.

A piezoelectric-body film joint substrate and a manufacturing method thereof according to each embodiment will be described below with reference to the drawings. The following embodiments are just examples and a variety of modifications are possible within the scope of the present disclosure. In the present application, the piezoelectric-body film joint substrate is a product as an intermediate in which a plurality of piezoelectric films are provided on the same substrate. While the piezoelectric films are desired to be monocrystalline piezoelectric films, it is also possible to form the piezoelectric-body film joint substrate with polycrystalline piezoelectric films.

By using a piezoelectric-body film joint substrate according to each embodiment, a piezoelectric film integrated device including a plurality of piezoelectric bodies can be manufactured. The piezoelectric film integrated device is an acoustic oscillation sensor, for example. Incidentally, the acoustic oscillation sensor is a sensor that detects status (e.g., distance, shape, movement or the like) of a detection target object by outputting an acoustic oscillatory wave and detecting reflected waves of the acoustic oscillatory wave. The acoustic oscillation sensor is referred to also as an "ultrasonic sensor". In general, and in the present application, the acoustic oscillatory wave is made up of at least one of a sonic wave and an ultrasonic wave. Namely, the acoustic oscillatory wave includes a sonic wave, an ultrasonic wave, or both of a sonic wave and an ultrasonic wave.

<FIG> is a side view schematically showing the structure of a piezoelectric-body film joint substrate <NUM> not forming part of the invention.

<FIG> is a top view schematically showing the structure of the piezoelectric-body film joint substrate <NUM>. <FIG> is a cross-sectional view of the piezoelectric-body film joint substrate <NUM> in <FIG> taken along the line S3-S3.

The piezoelectric-body film joint substrate <NUM> includes an SOI substrate <NUM> as a substrate and a platinum (Pt) film <NUM> as an electrode (i.e., substrate electrode) provided on the SOI substrate <NUM>. As shown in <FIG>, the Pt film <NUM> is connected to a wiring layer formed on the SOI substrate <NUM>. The SOI stands for Silicon On Insulator. Further, in the SOI substrate <NUM>, there may be formed a drive circuit for driving the piezoelectric-body film joint substrate <NUM> and thereby generating the acoustic oscillatory wave, a processing circuit that executes a process by using an acoustic oscillatory wave detection signal, and so forth.

The piezoelectric-body film joint substrate <NUM> includes an AlN piezoelectric-body film <NUM> as a first piezoelectric-body film stuck (i.e., bonded) on the Pt film <NUM> being the substrate electrode and a PZT piezoelectric-body film <NUM> as a second piezoelectric-body film stuck (i.e., bonded) on the AlN piezoelectric-body film <NUM>. The AlN piezoelectric-body film <NUM> includes an AlN film <NUM> as a first piezoelectric film and a Pt film <NUM> as a first upper electrode film formed on the AlN film <NUM>. The PZT piezoelectric-body film <NUM> includes a PZT film <NUM> as a second piezoelectric film different from the first piezoelectric film (e.g., in crystal structure) and a Pt film <NUM> as a second upper electrode film formed on the PZT film <NUM>, and is stuck on the Pt film <NUM>. Further, area of the PZT piezoelectric-body film <NUM> and area of the AlN piezoelectric-body film <NUM> differ from each other. The area of the PZT piezoelectric-body film <NUM> is smaller than the area of the AlN piezoelectric-body film <NUM>.

The AlN represents aluminum nitride. The PZT represents piezoelectric zirconate titanate (lead zirconate titanate). As the first piezoelectric-body film, instead of the AlN piezoelectric-body film, a different piezoelectric film such as a lithium tantalate (LiTaO<NUM>) piezoelectric-body film or a lithium niobate (LiNbO<NUM>) piezoelectric-body film may be used. As the second piezoelectric-body film, instead of the PZT piezoelectric-body film, a different piezoelectric-body film such as a potassium sodium niobate (KNN) piezoelectric-body film or a barium titanate (BaTiO<NUM>) piezoelectric-body film may be used. Further, while the first and second piezoelectric-body films are desired to be monocrystalline piezoelectric-body films, polycrystalline piezoelectric-body films may also be used. In the illustrated example, the first piezoelectric-body film is a piezoelectric body that detects the acoustic oscillatory wave (or its reflected waves), and is a piezoelectric body having lower specific inductive capacity and higher detection sensitivity compared to the second piezoelectric-body film. The second piezoelectric-body film is a piezoelectric body that generates the acoustic oscillatory wave, and is desired to be a piezoelectric body having a higher piezoelectric constant and capable of obtaining greater oscillation amplitude compared to the first piezoelectric-body film.

Incidentally, it is permissible even if the first piezoelectric-body film as a piezoelectric-body film on a lower side includes a PZT film and a Pt film and the second piezoelectric-body film as a piezoelectric-body film on an upper side includes an AlN film and a Pt film overlaid on the AlN film.

Further, as shown in <FIG>, the piezoelectric-body film joint substrate <NUM> includes an insulation film 35a, a wiring film 36a formed on the insulation film 35a, an insulation film 35b, and a wiring film 36b formed on the insulation film 35b.

The SOI substrate <NUM> includes a Si substrate <NUM>, a silicon dioxide (SiO<NUM>) part <NUM> as an insulation film, and a monocrystalline silicon (monocrystalline Si) part <NUM>. A cavity (hole) may be formed by etching the Si substrate <NUM> in a region of the monocrystalline Si part <NUM> under the PZT film <NUM> and the AlN film <NUM> (i.e., region overlapping with the piezoelectric films). The SiO<NUM> part <NUM> and the monocrystalline Si part <NUM> situated in the region where the cavity is formed have a function as a vibrating plate. Further, as the substrate, a substrate made of a different material such as a glass substrate or an organic film substrate may also be used instead of the SOI substrate <NUM>. The acoustic oscillatory wave generated by the PZT film <NUM> is outputted through the cavity, and the AlN film <NUM> detects reflected waves of the acoustic oscillatory wave through the cavity.

The thickness of the PZT film <NUM> is generally in a range of <NUM> to <NUM>, and preferably in a range of <NUM> to <NUM>. The thickness of the AlN film <NUM> is generally in a range of <NUM> to <NUM>, and preferably in a range of <NUM> to <NUM>. The Pt film <NUM> is formed on the upper surface of the SOI substrate <NUM>. The surface (upper surface) of the Pt film <NUM> and the AlN piezoelectric-body film <NUM> are joined together by intermolecular force. The surface of the Pt film <NUM> of the AlN piezoelectric-body film <NUM> and the PZT piezoelectric-body film <NUM> are joined together by intermolecular force. For these joints, the use of an adhesive agent is unnecessary. For excellently joining these surfaces by intermolecular force, the surface roughness of a sticking surface of the AlN piezoelectric-body film <NUM>, a sticking surface of the PZT piezoelectric-body film <NUM>, the Pt film <NUM> and the Pt film <NUM> is desired to be less than or equal to <NUM>. For this purpose, processes for smoothing the surfaces of the Pt film <NUM> and the Pt film <NUM> may be executed. Further, an interface when the sticking surface of the AlN piezoelectric-body film <NUM> has been stuck on the Pt film <NUM> is less than or equal to <NUM>. Furthermore, area of the surface of the Pt film <NUM> is desired to be larger than area of the sticking surface of the AlN piezoelectric-body film <NUM>. Thanks to such structure, a permissible range of a sticking accuracy error when the AlN piezoelectric-body film <NUM> is stuck on the Pt film <NUM> can be made wide.

In the manufacture of the piezoelectric-body film joint substrate <NUM>, the AlN piezoelectric-body film <NUM> formed on a growth substrate <NUM> and including the AlN film <NUM> and the Pt film <NUM> formed on the AlN film <NUM> and the PZT piezoelectric-body film <NUM> formed on a growth substrate <NUM> and including the PZT film <NUM> and the Pt film <NUM> formed on the PZT film <NUM> are peeled off respectively from the growth substrates <NUM> and <NUM>, the AlN piezoelectric-body film <NUM> is stuck on the Pt films <NUM> as the electrode formed on the SOI substrate <NUM> different from both of the growth substrates <NUM> and <NUM>, and the PZT piezoelectric-body film <NUM> is stuck on the AlN piezoelectric-body film <NUM>.

<FIG> is a flowchart showing a method of manufacturing the piezoelectric-body film joint substrate <NUM>. <FIG> are a top view and a cross-sectional view schematically showing the structure of a PZT epitaxial growth film in step ST101 in <FIG>. <FIG> are a top view and a cross-sectional view schematically showing the structure of the PZT epitaxial growth film in step ST102 in <FIG>. <FIG> are a top view and a cross-sectional view schematically showing the structure of an AlN epitaxial growth film in step ST104 in <FIG>. <FIG> are a top view and a cross-sectional view schematically showing the structure of the AlN epitaxial growth film in step ST105 in <FIG>. <FIG> are cross-sectional views schematically showing a holding process of a plurality of PZT piezoelectric-body films <NUM> in step ST103 in <FIG>. <FIG> are cross-sectional views schematically showing a holding process of a plurality of AlN piezoelectric-body films <NUM> in step ST106 in <FIG>. <FIG> is a cross-sectional view schematically showing a sticking process of the AlN piezoelectric-body film <NUM> in step ST107 in <FIG>, and <FIG> is a top view showing a state in which the AlN piezoelectric-body film <NUM> has been stuck. <FIG> is a cross-sectional view schematically showing a sticking process of the PZT piezoelectric-body film <NUM> in step ST108 in <FIG>, and <FIG> is a top view showing a state in which the PZT piezoelectric-body film <NUM> has been stuck. <FIG> is a cross-sectional view showing a manufacturing process of the next piezoelectric-body film joint substrate, and <FIG> is a top view showing a state in which the PZT piezoelectric-body film <NUM> has been stuck.

First, a sacrificial layer <NUM>, the PZT film <NUM> and the Pt film <NUM> are grown epitaxially on a growth substrate as shown in <FIG> (step ST101), and a plurality of PZT piezoelectric-body films <NUM> are formed by forming the PZT film <NUM> and the Pt film <NUM> into circular shapes by means of etching as shown in <FIG> (step ST102).

Further, a sacrificial layer <NUM>, the AlN film <NUM> and the Pt film <NUM> are grown epitaxially on another growth substrate as shown in <FIG> (step ST104), and a plurality of AlN piezoelectric-body films <NUM> are formed by forming the AlN film <NUM> and the Pt film <NUM> into circular shapes by means of etching as shown in <FIG> (step ST105).

Subsequently, as shown in <FIG>, the plurality of (<NUM> in the illustrated example) PZT piezoelectric-body films <NUM> as individual pieces each formed with the PZT film <NUM> and the Pt film <NUM> are held by a stamp <NUM> as a holding member and are peeled off by etching the sacrificial layer (step ST103). Further, as shown in <FIG>, the plurality of (<NUM> in the illustrated example) AlN piezoelectric-body films <NUM> as individual pieces each formed with the AlN film <NUM> and the Pt film <NUM> are held by a stamp <NUM> as a holding member and are peeled off by etching the sacrificial layer (step ST106).

Subsequently, as shown in <FIG>, one of the plurality of AlN piezoelectric-body films <NUM> held by the stamp <NUM> is stuck on the Pt film <NUM> (step ST107).

Subsequently, as shown in <FIG>, one of the plurality of PZT piezoelectric-body films <NUM> held by the stamp <NUM> is stuck on the Pt film <NUM> of the AlN piezoelectric-body film <NUM> that has been stuck on the Pt film <NUM> (step ST108). It is also possible to add a process of strengthening the sticking of Pt and each piezoelectric film by performing an annealing process after the sticking.

As shown in <FIG>, contact electrodes and a wiring pattern are formed with Pt on the SOI substrate <NUM>, the AlN piezoelectric-body film <NUM> is stuck, and thereafter the PZT piezoelectric-body film <NUM> is overlaid and stuck on the Pt film <NUM> as the upper electrode film of the AlN piezoelectric-body film <NUM>. In cases where the AlN piezoelectric-body films <NUM> held by the stamp <NUM> are in a <NUM> x <NUM> matrix, the AlN piezoelectric-body films <NUM> are successively stuck on different SOI substrates <NUM> in the illustrated order of #<NUM>, #<NUM>, #<NUM> and #<NUM>. In this case, the AlN piezoelectric-body film <NUM> as the piezoelectric-body film having greater diameter is stuck first. In this example, four SOI substrates <NUM> are prepared for the four piezoelectric-body films. The PZT piezoelectric-body film <NUM> is stuck on the AlN piezoelectric-body film <NUM> as shown in <FIG>. The sticking is executed successively in the order of #<NUM>, #<NUM>, #<NUM> and #<NUM>, and thus the stamp <NUM> as the holding member for sticking the PZT piezoelectric-body film <NUM> on the AlN piezoelectric-body film <NUM> is capable of executing the sticking without interfering with the AlN piezoelectric-body film <NUM> as shown in <FIG>.

Subsequently, the insulation film 35a and the wiring film 36a are formed on the PZT film <NUM> and the Pt film <NUM>, and the insulation film 35b and the wiring film 36b are formed on the AlN film <NUM> and the Pt film <NUM>.

At the time of the sticking, the hexagonal crystal of AlN and the cubic crystal of PZT are arranged in a phase relationship so that their c-axes are parallel to each other, by which efficiency of the piezoelectric oscillation driving of the PZT film <NUM> and the piezoelectric oscillation reception of the AlN film <NUM> is maximized.

<FIG> are a side view and a top view schematically showing the structure of a piezoelectric-body film joint substrate 100a not forming part of the invention.

The piezoelectric-body film joint substrate 100a differs from the piezoelectric-body film joint substrate <NUM> shown in <FIG> in that the two-dimensional shape of each of an AlN piezoelectric-body film 27a and a PZT piezoelectric-body film 17a is a quadrangular shape. Except for this feature, the piezoelectric-body film joint substrate 100a is the same as the piezoelectric-body film joint substrate <NUM>.

As described above, the PZT piezoelectric-body film <NUM> and the AlN piezoelectric-body film <NUM>, which are unlikely to grow epitaxially on the same SOI substrate <NUM> because of the difference in the lattice constant and the crystal structure, are respectively formed on separate growth substrates, peeled off from the growth substrates, and stuck on a common SOI substrate <NUM> in superimposition with each other, by which a high-performance piezoelectric-body film joint substrate <NUM> can be made.

Further, since the PZT film <NUM> being monocrystalline has a higher piezoelectric constant compared to a polycrystalline PZT film, amplitude of the oscillation can be increased with ease. Furthermore, since the AlN film <NUM> being monocrystalline has lower specific inductive capacity compared to a polycrystalline AlN film, the oscillation reception sensitivity can be increased. However, the PZT film <NUM> may contain polycrystalline PZT, and the AlN film <NUM> may contain polycrystalline AlN. Namely, monocrystallization ratios of the PZT film <NUM> and the AlN film <NUM> may be less than or equal to <NUM>%.

Furthermore, conventionally, in order to form piezoelectric films of different types, a process like temporarily covering one piezoelectric film with a protective layer, forming the other piezoelectric film, and thereafter removing the protective layer used to be a complicated process, and application of heat in processing in each step used to leave residual stress distortion in the piezoelectric films and cause deterioration in the efficiency of the sensor. By the manufacturing method described above, the piezoelectric-body film joint substrate and the acoustic oscillation sensor can be formed in a state with no residual stress distortion.

<FIG> are a side view and a top view schematically showing the structure of a piezoelectric-body film joint substrate <NUM> according to the invention. In <FIG>, each component identical or corresponding to a component shown in <FIG> is assigned the same reference character as in <FIG>.

The piezoelectric-body film joint substrate <NUM> includes an AlN piezoelectric-body film <NUM> as a first piezoelectric-body film stuck on a Pt film <NUM> and a PZT piezoelectric-body film <NUM> as a second piezoelectric-body film stuck on the AlN piezoelectric-body film <NUM>. The AlN piezoelectric-body film <NUM> includes a Pt film <NUM> as a first lower electrode film, the AlN film <NUM> as a first piezoelectric film formed on the Pt film <NUM>, and the Pt film <NUM> as a first upper electrode film formed on the AlN film <NUM>. The PZT piezoelectric-body film <NUM> includes a Pt film <NUM> as a second lower electrode film, the PZT film <NUM> as a second piezoelectric film different from the first piezoelectric film (e.g., in crystal structure), and the Pt film <NUM> as a second upper electrode film formed on the PZT film <NUM>, and the Pt film <NUM> is stuck on the Pt film <NUM>. Further, area of the PZT piezoelectric-body film <NUM> and area of the AlN piezoelectric-body film <NUM> differ from each other. In this embodiment, the area of the PZT piezoelectric-body film <NUM> is smaller than the area of the AlN piezoelectric-body film <NUM>. Except for the above-described features, the structure of the piezoelectric-body film joint substrate <NUM> is the same as that of the piezoelectric-body film joint substrate <NUM>. While the substrate electrode is formed with Pt (platinum) in this example, it is not particularly necessary to limit the material of the substrate electrode to Pt. For example, the substrate electrode may be formed with a variety of metal such as gold, aluminum or copper.

<FIG> is a cross-sectional view schematically showing the structure of an epitaxial growth film including the PZT piezoelectric-body film <NUM>. <FIG> is a cross-sectional view schematically showing the structure of an epitaxial growth film including the AlN piezoelectric-body film <NUM>. In the manufacture of the piezoelectric-body film joint substrate <NUM>, the AlN piezoelectric-body film <NUM> as the first piezoelectric-body film formed on the growth substrate <NUM> and including the Pt film <NUM>, the AlN film <NUM> and the Pt film <NUM> and the PZT piezoelectric-body film <NUM> formed on the growth substrate <NUM> and including the Pt film <NUM>, the PZT film <NUM> and the Pt film <NUM> are peeled off respectively from the growth substrates <NUM> and <NUM>, the AlN piezoelectric-body film <NUM> is stuck on the Pt films <NUM> formed on the SOI substrate <NUM> different from both of the growth substrates <NUM> and <NUM>, and the PZT piezoelectric-body film <NUM> is stuck on the AlN piezoelectric-body film <NUM>.

<FIG> is a flowchart showing a method of manufacturing the piezoelectric-body film joint substrate <NUM>. <FIG> are a top view and a cross-sectional view schematically showing the structure of a PZT epitaxial growth film in step ST201 in <FIG>. <FIG> are a top view and a cross-sectional view schematically showing the structure of the PZT epitaxial growth film in step ST202 in <FIG>. <FIG> are a top view and a cross-sectional view schematically showing the structure of an AlN epitaxial growth film in step ST204 in <FIG>. <FIG> are a top view and a cross-sectional view schematically showing the structure of the AlN epitaxial growth film in step ST205 in <FIG>. <FIG> are cross-sectional views schematically showing a holding process of a plurality of PZT piezoelectric-body films <NUM> in step ST203 in <FIG>. <FIG> are cross-sectional views schematically showing a holding process of a plurality of AlN piezoelectric-body films <NUM> in step ST206 in <FIG>. <FIG> is a cross-sectional view schematically showing a sticking process of the AlN piezoelectric-body film <NUM> in step ST207 in <FIG>, and <FIG> is a top view showing a state in which the AlN piezoelectric-body film <NUM> has been stuck. <FIG> is a cross-sectional view schematically showing a sticking process of the PZT piezoelectric-body film <NUM> in step ST208 in <FIG>, and <FIG> is a top view showing a state in which the PZT piezoelectric-body film <NUM> has been stuck.

First, the sacrificial layer <NUM>, a Pt film <NUM>, the PZT film <NUM> and the Pt film <NUM> are grown epitaxially on a growth substrate as shown in <FIG> (step ST201), and a plurality of PZT piezoelectric-body films <NUM> are formed by forming the Pt film <NUM>, the PZT film <NUM> and the Pt film <NUM> into circular shapes by means of etching as shown in <FIG> (step ST202).

Further, the sacrificial layer <NUM>, a Pt film <NUM>, the AlN film <NUM> and the Pt film <NUM> are grown epitaxially on another growth substrate as shown in <FIG> (step ST204), and a plurality of AlN piezoelectric-body films <NUM> are formed by forming the Pt film <NUM>, the AlN film <NUM> and the Pt film <NUM> into circular shapes by means of etching as shown in <FIG> (step ST205).

Subsequently, as shown in <FIG>, the plurality of (<NUM> in the illustrated example) PZT piezoelectric-body films <NUM> as individual pieces each formed with the Pt film <NUM>, the PZT film <NUM> and the Pt film <NUM> are held by the stamp <NUM> as the holding member and are peeled off by etching the sacrificial layer (step ST203). Further, as shown in <FIG>, the plurality of (<NUM> in the illustrated example) AlN piezoelectric-body films <NUM> as individual pieces each formed with the Pt film <NUM>, the AlN film <NUM> and the Pt film <NUM> are held by the stamp <NUM> as the holding member and are peeled off by etching the sacrificial layer (step ST206).

Subsequently, as shown in <FIG>, one of the plurality of AlN piezoelectric-body films <NUM> held by the stamp <NUM> is stuck on the Pt film <NUM> (step ST207). In this embodiment, an example in which the Pt film <NUM> is formed on a glass polyimide multilayer substrate <NUM> is shown. The glass polyimide multilayer substrate <NUM> is formed with a glass part <NUM> and a polyimide part <NUM> stacked on the glass part <NUM>, and the Pt film <NUM> is formed on the polyimide part <NUM>.

Subsequently, as shown in <FIG>, one of the plurality of PZT piezoelectric-body films <NUM> held by the stamp <NUM> is stuck on the Pt film <NUM> of the AlN piezoelectric-body film <NUM> that has been stuck on the Pt film <NUM> (step ST208). While it is desirable in the first embodiment to add the process of strengthening the sticking of Pt and each piezoelectric film by performing the annealing process after the sticking, it is unnecessary to perform the annealing process in this embodiment since each piezoelectric-body film has structure including the Pt film <NUM>, <NUM> as the upper electrode and the Pt film <NUM>, <NUM> as the lower electrode.

As shown in <FIG>, in this embodiment, the contact electrodes and the wiring pattern are formed with Pt on the glass polyimide multilayer substrate <NUM>, the AlN piezoelectric-body film <NUM> is stuck, and thereafter the PZT piezoelectric-body film <NUM> is overlaid and stuck on the Pt film <NUM> as the upper electrode film of the AlN piezoelectric-body film <NUM>. In cases where the AlN piezoelectric-body films <NUM> held by the stamp <NUM> are in a <NUM> x <NUM> matrix, the AlN piezoelectric-body films <NUM> are successively stuck on different glass polyimide multilayer substrates <NUM> in the illustrated order of #<NUM>, #<NUM>, #<NUM> and #<NUM>. In this case, the AlN piezoelectric-body film <NUM> as the piezoelectric-body film having greater diameter is stuck first. In this example, four glass polyimide multilayer substrates <NUM> are prepared for the four piezoelectric-body films. The PZT piezoelectric-body film <NUM> is stuck on the AlN piezoelectric-body film <NUM> as shown in <FIG>. The sticking is executed successively in the order of #<NUM>, #<NUM>, #<NUM> and #<NUM>, and thus the stamp <NUM> as the holding member for sticking the PZT piezoelectric-body film <NUM> on the AlN piezoelectric-body film <NUM> is capable of executing the sticking without interfering with the AlN piezoelectric-body film <NUM> as shown in <FIG>.

As described above, in this embodiment, the PZT piezoelectric-body film <NUM> and the AlN piezoelectric-body film <NUM>, which are unlikely to grow epitaxially on the same glass polyimide multilayer substrate <NUM>, are respectively grown epitaxially on separate growth substrates, peeled off from the growth substrates, and stuck on a common glass polyimide multilayer substrate <NUM> in superimposition with each other, by which a high-performance piezoelectric-body film joint substrate <NUM> can be made.

Further, according to the manufacturing method in this embodiment, the annealing process for stabilizing characteristics is necessary, and thus a plurality of piezoelectric-body films differing in the crystal structure can be provided on a non-heat-resistant substrate.

Incidentally, except for the above-described features, this embodiment is the same as the former not forming part of the invention.

Claim 1:
A piezoelectric-body film joint substrate (<NUM>) comprising:
a substrate (<NUM>, <NUM>);
a substrate electrode (<NUM>) provided on the substrate (<NUM>, <NUM>);
a first piezoelectric-body film (<NUM>) stuck on the substrate electrode (<NUM>) and including a first piezoelectric film (<NUM>) and a first upper electrode film (<NUM>) formed on the first piezoelectric film (<NUM>); and
a second piezoelectric-body film (<NUM>) stuck on the first upper electrode film (<NUM>) and including a second piezoelectric film (<NUM>) different from the first piezoelectric film (<NUM>) and a second upper electrode film (<NUM>) formed on the second piezoelectric film (<NUM>),
wherein the second piezoelectric-body film (<NUM>) further includes a second lower electrode film (<NUM>, <NUM>) formed on a surface of the second piezoelectric film (<NUM>) on a side opposite to the second upper electrode film (<NUM>) and joined to the first upper electrode film (<NUM>), characterized in that the second lower electrode film (<NUM>, <NUM>) has a first surface in contact with the second piezoelectric film (<NUM>) and a second surface on a side opposite to the first surface, a whole surface of the second surface being in direct contact with the first upper electrode film (<NUM>).