JP5333191B2 - Piezoelectric thin film manufacturing method and piezoelectric thin film manufacturing apparatus - Google Patents

Description

  The present invention relates to a piezoelectric thin film manufacturing method and a piezoelectric thin film manufacturing apparatus.

  In recent years, application development of piezoelectric elements, for example, development to memories, actuators and transducers of MEMS (Micro Electro Mechanical Systems), etc. has progressed, and the formation technology has attracted attention. In particular, methods for forming a thin film piezoelectric element include a sputtering method, an aerosol deposition method, a chemical solution method, and a chemical vapor deposition method. Of these, the sputtering method not only has high affinity for silicon processes, but also high integration by thinning, ease of thin film composition control by target composition, and deposition on a large-diameter substrate by increasing the target diameter. It is considered advantageous in terms of ease of mass production by the

A typical material of the piezoelectric element is lead zirconate titanate (hereinafter referred to as PZT). When PZT is formed by sputtering, a sintered target having Pb, Zr, Ti, and O is used. And O ₂ gas are introduced to form a film. When PZT is formed by sputtering, it is necessary to form a perovskite structure in order to exhibit high piezoelectric characteristics, and the crystallization temperature of the perovskite structure is in the range of about 550 ° C. to 600 ° C.

  The vapor pressure of Pb, which is a constituent element of PZT, is higher than Ti and Zr, which are other elements (sublimation temperatures at 1 Pa are Pb (lead) at 705 ° C., Ti at 1709 ° C., and Zr at 2366 ° C.) . FIG. 5 shows the relationship between the substrate temperature and the lead composition ratio during the production of the PZT thin film (Non-Patent Document 1). In FIG. 5, the horizontal axis represents a substrate temperature (° C.), and the vertical axis represents a value normalized with a lead composition ratio of 1 at a substrate temperature of PZT film formation of 550 ° C. As shown in FIG. 5, when the substrate temperature changes, the lead composition ratio changes. For example, when the temperature increases, the lead composition ratio decreases, leading to a decrease in crystallinity and a decrease in piezoelectric characteristics.

Supervised by Akira Nakamura, “High-performance piezoelectric materials and advanced applied technologies”, Science & Technology Co., Ltd., November 29, 2007, p. FIG. 4

  In order to manufacture a PZT element efficiently, for example, it is desirable to arrange a large-diameter substrate or a plurality of substrates with a small diameter on the entire surface facing the target. However, it is difficult to make the temperature distribution uniform over the entire surface of the large-diameter substrate, and a ferroelectric thin film with little variation in piezoelectric characteristics over the entire surface of the substrate cannot be obtained.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a piezoelectric thin film that efficiently manufactures a piezoelectric thin film with little variation in piezoelectric characteristics even on a large-area substrate. A manufacturing method and an apparatus for manufacturing a piezoelectric thin film are provided.

  Said subject is solved by the following structures.

1. In the method of manufacturing a piezoelectric thin film using a target made of lead zirconate titanate and manufacturing a lead zirconate titanate thin film on a substrate by a sputtering method,
A substrate heating step for heating the substrate;
Maintaining the temperature of the substrate heated in the substrate heating step, and forming a film on the substrate by the sputtering method,
In the substrate heating step, the substrate is heated to have a predetermined temperature distribution,
In the film formation step, oxygen is introduced so as to have a predetermined oxygen concentration distribution in a plane parallel to the plane of the target in a space between the substrate and the target,
When the surface of the target is vertically projected onto each of the substrate and the parallel surface, the increase / decrease direction of the predetermined temperature distribution and the predetermined oxygen concentration distribution at positions corresponding to each other between the substrate and the parallel surface. A method of manufacturing a piezoelectric thin film, wherein the direction of increase / decrease is the same direction.

  2. In the predetermined temperature distribution, the temperature of the center position where the center of the target is projected perpendicularly to the surface of the target is the highest on the substrate, and decreases from the center position toward the periphery. 2. The method for producing a piezoelectric thin film as described in 1 above.

  3. In the predetermined temperature distribution, the temperature of the center position at which the center of the target is projected perpendicularly to the surface of the target on the substrate is lowest and increases from the center position toward the periphery. 2. The method for producing a piezoelectric thin film as described in 1 above.

4). In the method of manufacturing a piezoelectric thin film using a target made of lead zirconate titanate and manufacturing a lead zirconate titanate thin film on a substrate by a sputtering method,
A substrate heating step for heating the substrate;
Maintaining the temperature of the substrate heated in the substrate heating step, and forming a film on the substrate by the sputtering method,
In the substrate heating step, the substrate is heated to have a predetermined temperature gradient,
In the film forming step, oxygen is introduced so that oxygen has a concentration gradient along the temperature gradient in a plane parallel to the surface of the target in a space between the substrate and the target. A method for producing a piezoelectric thin film, comprising:

  5. Oxygen is introduced so that the concentration of the oxygen in the plane of the parallel surface corresponding to the highest temperature portion on the substrate having the predetermined temperature gradient has the highest concentration gradient. 5. The method for producing a piezoelectric thin film as described in 4 above.

6). In a piezoelectric thin film manufacturing apparatus for manufacturing a lead zirconate titanate thin film on a substrate by a sputtering method using a target composed of lead zirconate titanate,
Substrate heating means for heating and maintaining the substrate to have a predetermined temperature distribution;
Oxygen introducing means for introducing oxygen so that a predetermined oxygen concentration distribution is obtained in a plane parallel to the surface of the target in a space between the substrate and the target;
When the surface of the target is vertically projected onto each of the substrate and the parallel surface, the increase / decrease direction of the predetermined temperature distribution and the predetermined oxygen concentration distribution at positions corresponding to each other between the substrate and the parallel surface. An apparatus for manufacturing a piezoelectric thin film, characterized in that the direction of increase / decrease is the same direction.

7). In a piezoelectric thin film manufacturing apparatus for manufacturing a lead zirconate titanate thin film on a substrate by a sputtering method using a target composed of lead zirconate titanate,
Substrate heating means for heating and maintaining the substrate to have a predetermined temperature gradient;
Oxygen introducing means for introducing oxygen so that oxygen has a concentration gradient along the temperature gradient in a plane parallel to the surface of the target in a space between the substrate and the target; An apparatus for manufacturing a piezoelectric thin film, comprising:

  According to the present invention, a piezoelectric thin film with little variation in piezoelectric characteristics can be efficiently manufactured on a large-area substrate.

It is a figure which shows the manufacturing apparatus based on this invention which forms a piezoelectric thin film. It is a figure which shows another example of the manufacturing apparatus based on this invention which forms a piezoelectric thin film. It is a figure which shows another example of the manufacturing apparatus based on this invention which forms a piezoelectric thin film. It is a figure which shows the process of manufacturing a piezoelectric element. It is a figure which shows the relationship between the substrate temperature at the time of PZT thin film manufacture, and lead composition ratio.

  Although the present invention will be described based on an embodiment, the present invention is not limited to the embodiment.

  In the process of reaching the present invention, the inventors have studied on making the composition ratio of lead uniform over the entire substrate when manufacturing a PZT (lead zirconate titanate) thin film by high-frequency magnetron sputtering. If the temperature of the entire substrate is made uniform, the composition ratio of lead can be made uniform, but it is difficult for the following reasons.

  Since the sputtering method is performed in a vacuum, heat transfer to the substrate is only radiation and heat conduction, so heat transfer does not occur. Therefore, since the temperature distribution of the substrate varies greatly depending on the state in which the substrate is in contact with the substrate holder, it becomes more difficult to make the temperature distribution uniform as the substrate becomes larger.

  When the substrate heating method is lamp heating, there is a method in which the contact between the substrate and the substrate holder is avoided as much as possible to suppress heat conduction and a temperature distribution plate is provided between the substrate and the lamp to improve the temperature distribution.

  However, in many cases, the temperature distribution of the lamp cannot be completely absorbed by the soaking plate, and the soaking plate alone is insufficient to make the temperature distribution of the substrate uniform. For example, when a PZT thin film is formed by providing a single lamp at the center and further by providing a soaking plate, depending on the size of the substrate, a 4-inch Si substrate is taken as an example in the center and the periphery of the substrate. In the portion, the variation width with respect to the average value of the piezoelectric constant d31 is as large as about ± 15%. Although it is conceivable to arrange a plurality of lamps and adjust the output of each lamp to make the temperature distribution of the substrate uniform, there is a problem that the apparatus becomes complicated and expensive.

  In addition, there is a method in which the substrate is attracted by an electrostatic chuck or the like and the substrate is heated by an SiC heater or the like. However, if the temperature distribution is made uniform, the apparatus becomes expensive as in the case of a lamp. Furthermore, if the substrate is warped or if there is foreign matter on the suction surface, the heat conduction between the substrate and the suction surface becomes non-uniform and it is difficult to obtain a good temperature distribution.

  In the process of studying the formation of PZT on a substrate by sputtering, the inventors do not know the reason, but if the oxygen concentration during film formation is increased, the lead content in the thin film increases. I understood that. A uniform PZT thin film can be formed on a large-area substrate by providing the oxygen concentration during film formation to a distribution that matches the substrate temperature distribution.

(First embodiment)
FIG. 1 schematically shows a PZT thin film manufacturing apparatus 100 (hereinafter referred to as manufacturing apparatus 100), which is a piezoelectric thin film formed by sputtering.

In the manufacturing apparatus 100, 1 is a chamber, 2 is a magnetron / cathode, 3 is a target made of PZT, 4 is a substrate holder (anode electrode), 5 is a substrate to be formed, and 6 is a heating unit for heating the substrate 5. , 8 represents an oxygen (O ₂ ) gas injection unit, and 9 represents a radio frequency (RF) power source for supplying radio frequency (RF) power to be applied to the magnetron cathode 2.

  A is a sputtering gas, for example, an argon (Ar) gas inlet, B is an exhaust port connected to a vacuum pump (not shown) for evacuating the chamber 1, and C is an oxygen gas supply path. Each is shown. When the circular substrate 5 is projected onto the circular target 3, the center positions of the two are almost the same.

  The substrate holder 4 shows a cross section that allows the disk-shaped substrate 5 to be attached. Further, in order to obtain a uniform film thickness on the substrate surface, the substrate holder 4 is preferably provided with a rotation introducing mechanism (not shown) so that it can rotate within the film formation surface during film formation. In addition, although the board | substrate 5 is shown as one sheet, you may arrange several sheets.

  The heating unit 6 includes a spot-type lamp 6a and a reflecting mirror 6b for directing the light of the spot-type lamp in one direction. The reflecting mirror 6b has a spheroidal shape, and a light emitting part such as a filament of the spot type lamp 6a is arranged at the focal position thereof so that the light beam emitted from the lamp can be made into a substantially parallel light beam.

  It is preferable to provide a soaking plate 7 between the substrate 5 held by the substrate holder 4 and the heating unit 6. The temperature distribution of the substrate 5 heated by the heating unit 6 has a gradient that is highest at the center of the substrate 5 and gradually decreases toward the periphery. By providing the soaking plate 7, the temperature distribution of the substrate 5 is the highest in the central part and gradually decreases toward the periphery, but the luminous flux emitted from the heating part 6 is diffused, and the temperature distribution. The degree of sharpness at the center of the film is moderately relaxed, and the distribution state becomes gentler.

  FIG. 1B is an overhead view showing the state of the oxygen gas injection unit 8 and the target 3 when the direction of the target 3 is viewed from the substrate 5 side. An ejection direction 8b of oxygen gas ejected from the oxygen gas ejection port 8a is schematically shown.

  As shown in FIG.1 (b), the oxygen gas injection part 8 is circular gas piping, Comprising: The oxygen gas introduce | transduced in gas piping is turned inward, and the target 3 exists in it. A plurality of oxygen gas ejection ports 8a ejecting downward are provided.

  The oxygen gas injection unit 8 is disposed at a moderate distance from the target 3 toward the substrate 5, oxygen gas is introduced into the oxygen gas injection unit 8, and a gas injection port 8 a is provided so that the oxygen gas collects at approximately the center of the target 3. Adjust the supply pressure of oxygen gas. Thereby, it is possible to have a concentration gradient such that the oxygen concentration is highest in the central portion and decreases from the central portion toward the periphery, along the temperature gradient.

  In FIG. 1, the gas outlet 8 a faces downward with the target 3, but the oxygen gas concentration is a direction substantially perpendicular to the direction in which the target 3 and the substrate 5 face each other in the space between the target 3 and the substrate 5. Thus, the distribution may be a distribution in which the vicinity of the center of the substrate (reference F) is the highest and decreases concentrically toward the outer periphery (in the direction of arrow G), and the direction of the gas outlet 8a may be horizontal.

  The concentration and gradient of the oxygen gas concentration distribution can be adjusted by the direction of the gas outlet 8a, the number of gas outlets 8a, the size of the gas outlet, and the level of the gas supply pressure. This is the same in the following third embodiment.

  As described above, in the temperature distribution of the substrate 5, the temperature in the central portion of the substrate is the highest and has a gradient that gradually decreases toward the periphery, whereas in the atmosphere of the chamber 1, Has a gradient that is the highest and gradually decreases toward the outer periphery (in the direction of arrow G). For this reason, the PZT thin film formed on the substrate 5 has a higher central temperature than the periphery depending on the temperature distribution of the substrate 5, so that the lead composition ratio tends to be small in the central portion and large in the peripheral portion. On the other hand, depending on the oxygen concentration, the oxygen concentration at the center is higher than that at the periphery, so the lead composition ratio is large at the center and tends to be small at the periphery.

  Therefore, by adjusting the temperature distribution and the oxygen concentration distribution of the substrate 5, the Pb composition ratio of the piezoelectric thin film formed on the substrate 5 can be reduced over the entire surface of the substrate 5.

  In FIG. 1B, a large number of gas outlets 8a are provided inside the ring-shaped gas pipe, and the gas outlets 8a are equally spaced. However, the present invention is not limited to this, and the exhaust port of the chamber 1 is not limited to this. In consideration of the position and the position of the sputter gas introduction port such as Ar gas, the number and arrangement of the ejection ports may be determined as appropriate so that the oxygen concentration is not unevenly distributed. A nozzle for increasing the directivity in the gas ejection direction may be provided at the gas ejection port 8a so that the oxygen concentration is efficiently collected at the center of the target.

  The soaking plate 7 is preferably made of a material with high thermal conductivity that can obtain a uniform temperature distribution and high thermal responsiveness, and is preferably a material that is resistant to high temperatures so as not to contaminate the inside of the chamber 1. Specific examples of the material include SiC, AlN, and SiN. Further, since the sputtering method is a vacuum process, the heat transfer from the spot lamp 6a to the heat equalizing plate 7 and the heat transfer from the heat equalizing plate to the substrate 5 are radiated, although it depends on the method of holding the heat equalizing plate. Become dominant. Therefore, in order to efficiently transfer heat from the spot type lamp 6a to the substrate 5, it is desirable that the radiation rate of the soaking plate 7 is high.

(Second Embodiment)
FIG. 2A is a cross-sectional view of the main part of a manufacturing apparatus 200 having a heating unit 6 and a gas injection unit 18 in which the champ 1 and the like are omitted and showing another embodiment of the present invention, and FIG. FIG. 6 is an overhead view showing the state of the oxygen gas injection unit 18 and the target 3 when the direction of the target 3 is viewed from the substrate 5 side.

  The heating unit 6 is the same as that in the first embodiment, and because of the spot type lamp 6a and the reflecting mirror 6b, the temperature distribution of the substrate 5 has the highest gradient at the center and gradually decreases toward the periphery. ing.

  As shown in FIG. 2B, the gas injection unit 18 is configured such that the tip of the gas injection port 18a is installed at the center upper portion of the target 3 and oxygen gas is directed downward from the gas injection port 18a toward the center of the target. It is supposed to erupt. The oxygen gas ejected to the center of the target 3 spreads from the center to the periphery on the upper surface of the target 3, and the oxygen concentration distribution is highest at the center of the target 3 along the temperature gradient. It has a lower slope.

  As in the first embodiment, in the temperature distribution of the substrate 5, the temperature at the center of the substrate is the highest and gradually decreases toward the periphery, whereas in the oxygen concentration distribution, the temperature of the target 3 The oxygen concentration at the center of the surface is the highest and has a gradient that gradually decreases toward the outer periphery.

  For this reason, the PZT thin film formed on the substrate 5 has a temperature distribution of the substrate 5 whose temperature at the center is higher than that at the periphery, so that the lead composition ratio is small in the center and large in the periphery. On the other hand, with regard to the oxygen concentration, the oxygen concentration in the central portion is higher than that in the periphery, so that the lead composition ratio is large in the central portion and tends to be small in the peripheral portion.

  Therefore, by adjusting the temperature distribution and oxygen concentration distribution of the substrate 5, the lead composition ratio of the piezoelectric thin film formed on the substrate 5 can be less varied over the entire surface of the substrate 5.

  In the present embodiment, since the gas injection unit 18 is disposed close to the target 3 so as to indicate a radius, the film quality distribution is shaded by particles from the target 3 during film formation on the substrate 5. Although there is a concern that it may occur, film quality distribution can be prevented by rotating the substrate 5 with respect to the target 3.

(Third embodiment)
FIG. 3A is a cross-sectional view of a main part of a manufacturing apparatus 300 having a heating unit 26 and a gas injection unit 28, in which the champ 1 and the like are omitted, and showing another embodiment of the present invention. These are overhead views which show the state of the oxygen gas injection part 28 and the target 3 when seeing the direction of the target 3 from the board | substrate 5 side.

  Since the heating unit 26 is a circle-shaped lamp 26a, the temperature distribution of the substrate 5 has a gradient in which the outer peripheral side is the highest and the temperature gradually decreases from the outer peripheral side toward the central part.

  Further, as shown in FIG. 3B, the oxygen gas injection unit 28 is a circular gas pipe, and the oxygen gas introduced into the gas pipe is directed inwardly on the inside thereof, and the upper surface of the target 3 Are provided with a plurality of gas ejection ports 28a ejecting in a substantially horizontal direction. In this way, by providing the oxygen gas outlets 28a along the outer periphery of the target and adjusting the supply pressure of the oxygen gas toward the center, the oxygen concentration distribution of the target 3 along the temperature gradient is adjusted. It is possible to have a gradient that is highest at the peripheral portion and decreases from the peripheral portion of the target 3 toward the central portion.

  Therefore, in the present embodiment, contrary to the first and second embodiments, the temperature distribution of the substrate 5 has a gradient in which the temperature around the substrate is the highest and gradually decreases toward the center. On the other hand, in the oxygen concentration distribution, the oxygen concentration in the vicinity of the outside of the target 3 is the highest and has a gradient gradually decreasing toward the center near the surface of the target 3.

  For this reason, the PZT thin film formed on the substrate 5 has a temperature distribution of the substrate 5 in which the temperature of the peripheral portion is higher than that of the central portion, so that the lead composition ratio is small in the peripheral portion and large in the central portion. On the other hand, as for the oxygen concentration, since the oxygen concentration in the central portion is lower than that in the peripheral portion, the lead composition ratio is relatively large in the peripheral portion and tends to be small in the central portion.

  Therefore, by adjusting the temperature distribution of the substrate 5 and the oxygen concentration distribution in the vicinity of the target 3, the Pb composition ratio of the piezoelectric thin film formed on the substrate 5 may be less varied over the entire surface of the substrate 5. it can.

Example 1
A piezoelectric thin film was manufactured using the piezoelectric thin film manufacturing apparatus 100 and its piezoelectric characteristics were measured. This will be described using the manufacturing process of the piezoelectric thin film shown in FIG.

First, an Si (titanium) film having a thickness of 20 nm and a Pt (platinum) film having a thickness of 100 nm as an adhesion layer was formed on a 4-inch Si substrate 5a with a thermal oxide film by sputtering (FIG. 4A). ). The film formation conditions at this time are as follows:
Ti layer: Ar flow rate 10 sccm, pressure 0.5 Pa, high frequency power 200 W,
Pt layer: Ar flow rate 20 sccm, pressure 0.2 Pa, high frequency power 150 W,
It was.

  The Pt layer is formed with the substrate heated at 400 ° C. After film formation of the Pt layer, the crystallinity was measured by the XRD method (X-ray diffraction method), and it was confirmed that it was oriented in the (111) plane. The Si substrate with a thermal oxide film in which the Ti layer and the Pt layer 5b are stacked is used as a substrate 5 on which a piezoelectric thin film is formed. The Pt layer 5b functions as a lower electrode.

  Next, using the manufacturing apparatus 100 shown in FIG. 1, a PZT thin film 20 having a thickness of about 3 μm was formed on the substrate 5 by the method for manufacturing a piezoelectric thin film according to the present invention (FIG. 4B). In the heating unit 6, the spot type lamp 6 a was turned on, the substrate 5 was heated via the soaking plate 7, and the film was formed in a state where the temperature was stable. The temperature at the periphery of the substrate 5 during film formation was about 550 ° C., and the temperature at the center was about 600 ° C.

  The distance between the target 3 and the substrate 5 is about 50 mm, the distance from the target to the oxygen gas injection unit 8 is about 10 mm, the inner diameter of the ring shape of the oxygen gas injection unit 8 is about 170 mm, and the diameter of the tube of the oxygen gas injection unit 8 is The 10 mm oxygen gas outlet 8 a is provided at a position where a hole with a diameter of 4 mm divides the inside of the circumference into 30 equal parts.

The target 3 has a composition of Pb _1.5 (Zr _0.52 Ti _0.48 ) O _{X with} a diameter of 6 inches, and the film forming conditions are Ar flow rate 10 sccm, oxygen flow rate 0.8 sccm, pressure 0.3 Pa, high frequency The power was 400W.

  Next, a Pt layer was formed on the PZT thin film as the upper electrode 21 by sputtering. The film formation conditions at this time were an Ar flow rate of 20 sccm, a pressure of 0.2 Pa, and a high frequency power of 150 W, and the film was formed using a stainless stencil mask to expose a part of the PZT thin film (FIG. 4C). ).

  Next, a photosensitive resist 22 was applied with a thickness of about 3 μm, and a photolithography process was performed so that only the upper electrode was covered with the photosensitive resist (FIG. 4D). At the time of photolithography, baking at about 90 ° C. was performed after development in order to increase the resistance of the photosensitive resist to subsequent etching.

  Next, etching was performed using an etching solution containing hydrofluoric acid until the lower electrode layer was exposed, and a part of PZT was removed (FIG. 4E).

  Next, after removing the photosensitive resist using an alkaline stripping solution, the piezoelectric element was separated into individual piezoelectric elements by dicing so that the size of the piezoelectric element was 15 mm long and 2 mm wide (FIG. 4F). ). The piezoelectric element can be separated not only by dicing but also by Si dry etching.

  Next, the thermosetting conductive paste 23 is provided on the upper electrode 21 and the lower electrode 5b (FIG. 4G), and the wiring member 24 is heated to the curing temperature while being in contact with the thermosetting conductive paste 23. Thus, the wiring member 24 was bonded to the upper electrode 21 and the lower electrode 5b (FIG. 4H).

  Two piezoelectric elements were cut out from the center of the substrate 5 and the ends of the piezoelectric elements were clamped 30 and fixed so as to form a cantilever having a movable length of 10 mm (FIG. 4 (i)). Furthermore, when the upper electrode is set to GND, a voltage of 10 V amplitude and frequency of 500 Hz is applied to the lower electrode, and the displacement amount is measured with a laser Doppler meter using the end A of the piezoelectric element as a displacement observation point. Was 2 μm.

  From this piezoelectric displacement, the piezoelectric constant d31 was calculated by the following equation (1) (reference: I. Kanno et al. Sensors and Actuators A 107 (2003) 68-74).

Here, h ^s is the substrate thickness, the s ^p elastic compliance of the thin film PZT, s ^s is the elastic compliance of the substrate, L is the length of the cantilever, V is the applied voltage, [delta] is the displacement of the cantilever. Therefore, from h ^s = 400 μm, s ^p = 90 GPa, s ^s = 180 GPa, and L = 10 mm, the piezoelectric constant d31 = −160 pm / V.

  Similarly, the piezoelectric constant d31 was calculated in the same manner as described above for four piezoelectric elements cut out from the outer peripheral portion of the substrate 5. As a result, the piezoelectric constant d31 of all the six piezoelectric elements is within ± 6% of the average value of all, and is well within ± 10% considered to be a practical range, and the 4-inch substrate 5 It was confirmed that a piezoelectric element with little variation in characteristics could be formed at any location.

  Separately, it is the same as described above until a PZT thin film is formed on the substrate 5 (FIG. 4B), and thereafter, one piece from the central portion of the substrate 5 and four pieces from the outer peripheral portion by dicing in the state of a piezoelectric element without an upper electrode. Cut out. As a result of measuring the composition of these piezoelectric elements with a fluorescent X-ray composition analyzer, it was confirmed that the compositions of the piezoelectric element in the central part of the substrate and the piezoelectric element in the peripheral part were almost the same.

DESCRIPTION OF SYMBOLS 1 Chamber 2 Magnetron cathode 3 Target 4 Substrate holder 5 Substrate 6 Heating part 6a Spot type lamp 6b Reflector 7 Soaking plate 8 Oxygen gas injection part 8a Gas outlet 8b Ejection direction 9 High frequency power supply A Argon gas inlet B Exhaust Port C Oxygen gas supply path 100 Manufacturing equipment

Claims (7)

In the method of manufacturing a piezoelectric thin film using a target made of lead zirconate titanate and manufacturing a lead zirconate titanate thin film on a substrate by a sputtering method,
A substrate heating step for heating the substrate;
Maintaining the temperature of the substrate heated in the substrate heating step, and forming a film on the substrate by the sputtering method,
In the substrate heating step, the substrate is heated to have a predetermined temperature distribution,
In the film formation step, oxygen is introduced so as to have a predetermined oxygen concentration distribution in a plane parallel to the plane of the target in a space between the substrate and the target,
When the surface of the target is vertically projected onto each of the substrate and the parallel surface, the increase / decrease direction of the predetermined temperature distribution and the predetermined oxygen concentration distribution at positions corresponding to each other between the substrate and the parallel surface. A method of manufacturing a piezoelectric thin film, wherein the direction of increase / decrease is the same direction.   In the predetermined temperature distribution, the temperature of the center position where the center of the target is projected perpendicularly to the surface of the target is the highest on the substrate, and decreases from the center position toward the periphery. The method for producing a piezoelectric thin film according to claim 1.   In the predetermined temperature distribution, the temperature of the center position at which the center of the target is projected perpendicularly to the surface of the target on the substrate is lowest and increases from the center position toward the periphery. The method for producing a piezoelectric thin film according to claim 1. In the method of manufacturing a piezoelectric thin film using a target made of lead zirconate titanate and manufacturing a lead zirconate titanate thin film on a substrate by a sputtering method,
A substrate heating step for heating the substrate;
Maintaining the temperature of the substrate heated in the substrate heating step, and forming a film on the substrate by the sputtering method,
In the substrate heating step, the substrate is heated to have a predetermined temperature gradient,
In the film forming step, oxygen is introduced so that oxygen has a concentration gradient along the temperature gradient in a plane parallel to the surface of the target in a space between the substrate and the target. A method for producing a piezoelectric thin film, comprising:   Oxygen is introduced so that the concentration of the oxygen in the plane of the parallel surface corresponding to the highest temperature portion on the substrate having the predetermined temperature gradient has the highest concentration gradient. The method for producing a piezoelectric thin film according to claim 4. In a piezoelectric thin film manufacturing apparatus for manufacturing a lead zirconate titanate thin film on a substrate by a sputtering method using a target composed of lead zirconate titanate,
Substrate heating means for heating and maintaining the substrate to have a predetermined temperature distribution;
Oxygen introducing means for introducing oxygen so that a predetermined oxygen concentration distribution is obtained in a plane parallel to the surface of the target in a space between the substrate and the target;
When the surface of the target is vertically projected onto each of the substrate and the parallel surface, the increase / decrease direction of the predetermined temperature distribution and the predetermined oxygen concentration distribution at positions corresponding to each other between the substrate and the parallel surface. An apparatus for manufacturing a piezoelectric thin film, characterized in that the direction of increase / decrease is the same direction. In a piezoelectric thin film manufacturing apparatus for manufacturing a lead zirconate titanate thin film on a substrate by a sputtering method using a target composed of lead zirconate titanate,
Substrate heating means for heating and maintaining the substrate to have a predetermined temperature gradient;
Oxygen introducing means for introducing oxygen so that oxygen has a concentration gradient along the temperature gradient in a plane parallel to the surface of the target in a space between the substrate and the target; An apparatus for manufacturing a piezoelectric thin film, comprising:

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