JP2009242927A - Sputtering method and sputtering apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sputtering method and a sputtering apparatus for achieving the high quality of a film by preventing any reverse sputter by simple constitution and simple control, controlling the deviation of the composition, enhancing reproducibility of the film deposition, and depositing a piezoelectric film of high quality having no change in the film quality, and a thin film such as an insulating film and a conductive film. <P>SOLUTION: The sputtering apparatus has a sputtering electrode for holding a target and a substrate holder which is arranged opposite to the sputtering electrode to hold a substrate in a vacuum vessel, and has an impedance adjusting circuit having an impedance circuit capable of adjusting impedance of the substrate holder. By adjusting the impedance of the impedance circuit, the impedance of the substrate holder is adjusted, and the electric potential of the substrate is adjusted thereby. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sputtering method and apparatus, and more particularly, to a thin film such as an insulating film (insulator), a dielectric film (dielectric), or a ferroelectric (piezoelectric) composition by a vapor phase growth method using plasma. The present invention relates to a sputtering method for forming a film and a sputtering apparatus used for carrying out the method.

  2. Description of the Related Art Conventionally, in order to form a thin film such as a piezoelectric film, an insulating film, and a dielectric film, a sputtering method for forming a film by a vapor phase growth method using plasma and a sputtering apparatus for performing the method have been used. In such a sputtering method and apparatus, plasma ions such as high-energy Ar ions generated by plasma discharge in a high vacuum are collided with the target to release the constituent elements of the target, and the released constituent elements of the target Is deposited on the surface of the substrate to form a thin film on the substrate.

In the sputtering method and apparatus, in order to form a high-quality thin film, sputtering is performed by applying a predetermined potential to the surface of the substrate held by the substrate electrode disposed at a position facing the sputtering electrode provided in the vacuum vessel. It is carried out.
In a thin film device manufactured by such a sputtering method and apparatus, it is required to control the film thickness, composition, crystal phase, and the like in the thin film to suppress variations in in-plane characteristics.

For this reason, when forming a thin film with a sputtering apparatus, it is required to make the in-plane uniform by uniformizing the plasma state (see, for example, Patent Documents 1, 2, 3, 4 and 5). ).
In Patent Document 1, in order to make the film thickness distribution and the film composition of the thin film uniform, an electromagnet that can control the polarity and strength is used as a magnet for forming a magnetic field in the vicinity of the target to control the formed magnetic field. Thus, a technique for generating uniform plasma without abnormal discharge and realizing uniform erosion over the entire target surface is disclosed. Thus, it is well known to devise on the target (cathode) side in order to generate uniform plasma.

By the way, it is known that plasma uniformity is required even when an insulator (insulator / dielectric / pyroelectric / piezoelectric material) is formed instead of metal.
For this reason, for example, in Patent Document 2, a device is added to the potential on the side wall of the sputtering apparatus. Patent Document 2 describes a method of generating an insulating film having a uniform composition by controlling the plasma by controlling the potential of the sidewall along with the insulating film adhesion when forming the insulating film with a sputtering apparatus. Yes.

In addition, with respect to the device on the target side and the device on the side wall of the apparatus, attempts have been made to uniformize the film formation of the insulating film by controlling the plasma state in the vicinity of the film formation substrate.
Patent Document 3 discloses a technique for producing an insulating film having a uniform composition distribution in the film by insulating the film formation substrate and the sputtering apparatus to form uniform plasma.
However, although the techniques disclosed in Patent Documents 1, 2 and 3 improve the film quality from each point, it is not sufficient to make the film quality more uniform with this alone, and therefore, the vicinity of the film formation substrate. The masks and jigs are devised.

  Patent Document 4 discloses a technique for selecting an appropriate film formation condition by setting a mask installed near a film formation substrate to a floating potential, dropping it to ground, or combining both. Specifically, as a film formation mask (film formation jig), an earth mask connected to the earth potential, a floating mask insulated from the earth potential, a part connected to the earth potential, and a part insulated from the earth potential And the amount of the portion connected to the ground potential of the plasma control mask and the floating portion insulated from the ground potential is adjusted to obtain optimum film forming conditions.

  Further, in Patent Document 5, a substrate holding member that holds a substrate to be processed and an adhesion preventing member that is provided with the substrate holding member and disposed between the apparatus main body via an insulating member are equipotential and floating. Thus, a technique is disclosed in which abnormal discharge can be suppressed, the film formation rate can be improved, and the film thickness uniformity can be improved. In addition, in Patent Document 5, in addition to making the substrate holding member and the adhesion member described above equipotential, the potential of the adhesion member is switched to ground or floating, thereby changing the type of film between the insulating film and the conductive film. Since the potential state can be changed accordingly, a technique capable of achieving the above-described effect depending on the type of the film is disclosed.

JP-A-6-41740 JP 2007-42919 A Japanese Patent Laid-Open No. 7-231045 JP 2001-335930 A JP 2006-83459 A

  However, in Patent Document 4, there is a description that the ground portion and the floating portion are in an appropriate ratio, but there is no particular reason and the optimum condition is determined by trial and error. Therefore, there is a problem in that trial and error must be repeated each time the plasma state changes such as an insulator on the side wall or a change in the target material. The technique disclosed in Patent Document 4 forms a thin film with a uniform film thickness. However, the uniformity of the film quality such as the electrical characteristics of the thin film, for example, the uniformity of the insulating characteristics of the insulating film, etc. However, there is a problem that in-plane uniformity is not considered at all.

  Further, Patent Document 5 describes that the film thickness is uniform, but as in Patent Document 4, the film quality such as the electrical characteristics of the thin film, for example, the insulating film such as the insulating characteristics such as the insulating film. There has been a problem that the details of the electrical characteristics of the end of the slab have not been studied and are insufficient. That is, in the technique disclosed in Patent Document 5, the substrate holding member and the adhesion-preventing member are made to be equipotential to prevent the occurrence of abnormal discharge between the two, and the film thickness is not reduced. It is only a technique for making the distribution uniform, and the uniformity of the film quality such as the electrical characteristics of the thin film, for example, the uniformity of the insulation characteristics of the insulating film, especially the in-plane uniformity is not considered at all. There's a problem.

  The object of the present invention is to solve the above-mentioned problems of the prior art, there is no variation in film quality and compositional deviation, and there is no high quality insulating film excellent in uniformity of film characteristics such as electrical characteristics, particularly in-plane uniformity. It is an object of the present invention to provide a sputtering method and apparatus capable of forming a thin film such as a conductor film, for example, a thin film such as an insulating film excellent in uniformity of insulation characteristics, particularly in-plane uniformity.

  In order to solve the above-mentioned problems, the present inventors have studied many conventional techniques including the above-mentioned Patent Documents 1 to 5 in order to achieve the above object, and have high quality excellent in such film characteristics. As a result of earnest research on the sputtering method and the sputtering apparatus capable of forming a thin film, it is found that the film characteristics such as the insulation characteristics and the electrical characteristics are not uniform only by the techniques of the above Patent Documents 4 and 5. I found it. In other words, the inventors of both Patent Documents 4 and 5 consider the potential at the peripheral portion of the substrate, but have not considered the relationship between the potential of the deposition substrate and the peripheral portion. Film characteristics such as electrical characteristics and electrical characteristics are not uniform, especially when a thin film is formed on a semiconductor substrate such as a silicon substrate as a substrate to be processed as in Patent Document 5. In order to improve the film-forming speed, it is sufficient to make the substrate holding member and the adhesion-preventing member equipotential to prevent the occurrence of abnormal discharge between them. In order to form an insulating film such as a piezoelectric curtain on the conductive surface of the film, it is not enough to find that the film characteristics cannot be made uniform. Conductive on the outside of the deposition substrate with the surface And it found that it is necessary to install the equipotential surface forming member having a surface and equipotential surface is equipotential, and have reached the present invention.

  That is, the first aspect of the present invention is a sputtering method for forming a thin film on a film-forming substrate having a conductive surface on at least one surface, wherein the film-forming substrate is provided outside the film-forming substrate. A sputtering method is provided, wherein an equipotential surface forming member having an equipotential surface that is equipotential with a conductive surface is installed, and the thin film is formed on the conductive surface of the deposition substrate. To do.

Here, on the outside of the film formation substrate, the area of the equipotential surface of the equipotential surface forming member is preferably 40% or more of the area of the conductive surface of the film formation substrate, More preferably, it is 70% or more, and most preferably 150% or more.
The equipotential surface forming member is preferably a member having a thickness of 10 μm or less of the insulating film attached to the equipotential surface, and most preferably, the insulating film is attached to the equipotential surface. It is good that it is not a member.
Further, the film is formed on the conductive surface of the deposition substrate while the thickness of the insulating film attached to the equipotential surface of the equipotential surface forming member is 0 or 10 μm or less. preferable.

The film forming material for forming the film is preferably an insulator, and more preferably contains lead titanate or lead zirconate.
The film formation substrate is preferably a conductive substrate.
In addition, it is preferable that the conductive surface of the deposition substrate and the equipotential surface of the equipotential surface forming member are electrically connected.
Further, the equipotential surface forming member is installed so that the equipotential surface is closer to or comes closer to the film forming material for forming the film than the conductive surface of the film forming substrate. Is preferred.

  In order to achieve the above object, a second aspect of the present invention is a vacuum vessel, a sputter electrode provided in the vacuum vessel and holding a target material for sputtering, and connected to the sputter electrode. A high frequency power source for applying a high frequency to the sputter electrode, and a space in the vacuum vessel that is spaced apart from the sputter electrode, a thin film is formed by the component of the target material, and at least one surface is conductive A substrate holder that holds the film-forming substrate having the surface of the substrate, and the equipotential surface forming member that is installed outside the film-forming substrate held by the substrate holder. Sputtering having an equipotential surface that is equipotential with the conductive surface of the deposition substrate, and the thin film is formed on the conductive surface of the deposition substrate It is to provide a location.

Here, the equipotential surface forming member preferably has an area of the equipotential surface outside the film formation substrate of 40% or more of the area of the conductive surface of the film formation substrate. More preferably, it is 70% or more, and most preferably 150% or more.
The film formation substrate is preferably a conductive substrate.
Moreover, it is preferable that the conductive surface of the film formation substrate and the equipotential surface of the equipotential surface forming member are electrically connected.

The equipotential surface forming member is preferably a member having a thickness of 10 μm or less of the insulating film attached to the equipotential surface, and most preferably, the insulating film is attached to the equipotential surface. It is good that it is not a member.
In the equipotential surface forming member, the thickness of the insulating film attached to the equipotential surface is preferably 0 or 10 μm or less.
Moreover, it is preferable that the film-forming material for producing the film is an insulator.
Moreover, it is preferable that the film-forming material for producing the film contains lead titanate or lead zirconate.
The equipotential surface forming member is preferably installed so that the equipotential surface is on or nearer to the sputter electrode than the conductive surface of the film formation substrate.

According to the first and second aspects of the present invention, there is no variation in film quality and compositional deviation, and uniformity of film characteristics such as electrical characteristics, in particular, high-quality insulating film and conductivity excellent in in-plane uniformity. There is an effect that it is possible to form a thin film such as a body film, for example, a thin film such as an insulating film excellent in uniformity of insulation characteristics, particularly in-plane uniformity.
In particular, there is no variation in film quality or composition deviation, and it is made of a Pb-containing perovskite oxide such as PZT, and a perovskite crystal with a small pyrochlore phase is stably grown, and Pb detachment is stably suppressed, resulting in uniform insulation characteristics. In particular, a piezoelectric film having excellent in-plane uniformity can be formed.

Hereinafter, the sputtering method according to the first aspect of the present invention and the sputtering apparatus according to the second aspect of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
FIG. 1 is a schematic cross-sectional view conceptually showing an apparatus configuration of an embodiment of a sputtering apparatus of the present invention for carrying out the sputtering method of the present invention. In the following, a sputtering apparatus for forming a piezoelectric film as a thin film will be described as a representative example, but it goes without saying that the present invention is not limited to this.

  As shown in the figure, the sputtering apparatus 10 of the present invention includes an insulating film and a dielectric on a conductive surface SBa of a deposition substrate (hereinafter simply referred to as a substrate) SB having a conductive surface on at least one surface. An insulating thin film such as a piezoelectric film is formed on the conductive surface SBa of the substrate SB by a vapor phase growth method (sputtering) for forming a thin film such as a film, particularly a piezoelectric film. An RF sputtering apparatus for manufacturing a thin film device such as a piezoelectric element, which is provided in a vacuum vessel 12 having a gas introduction tube 12a and a gas discharge tube 12b, and in this vacuum vessel (also referred to as a vacuum chamber) 12, and for sputtering A sputter electrode (cathode electrode) 14 that holds the target material TG and generates plasma, and is connected to the sputter electrode 14 so that the sputter electrode 14 A high frequency power source 16 for applying waves, a substrate holder 18 for holding a substrate SB on which a thin film made of a component of the target material TG is formed, disposed in a position facing the sputtering electrode 14 in the vacuum vessel 12, and a substrate holder 18 and an equipotential surface forming member 20 having an equipotential surface 20a that is equipotential with the conductive surface SBa of the substrate SB.

The vacuum container 12 is a highly airtight container formed of iron, stainless steel, aluminum or the like that maintains a predetermined degree of vacuum for performing sputtering. In the illustrated example, the vacuum container 12 is grounded and forms a film therein. A gas introduction pipe 12a for introducing the necessary gas and a gas discharge pipe 12b for exhausting the gas in the vacuum vessel 12 are attached. As a gas introduced into the vacuum vessel 12 from the gas introduction tube 12a, argon (Ar), a mixed gas of argon (Ar) and oxygen (O ₂ ), or the like can be used. The gas introduction pipe 12a is connected to a supply source (not shown) of these gases. On the other hand, the gas discharge pipe 12b has a predetermined degree of vacuum inside the vacuum vessel 12, and in order to exhaust the gas in the vacuum vessel 12 in order to maintain the predetermined degree of vacuum during film formation, a vacuum pump or the like Connected to the exhaust means.
In addition, as the vacuum container 12, various vacuum containers, such as a vacuum chamber, a bell jar, and a vacuum tank, which are used in a sputtering apparatus can be used.

The sputter electrode 14 is disposed above the inside of the vacuum vessel 12, and a target material TG having a composition corresponding to the composition of a thin film such as a piezoelectric film to be formed on the surface (upper surface in the drawing) is mounted and held. And is connected to the high-frequency power supply 16.
The high-frequency power source 16 is for supplying high-frequency power (negative high-frequency) for making the gas such as Ar introduced into the vacuum vessel 12 into plasma to the sputter electrode 14, and one end thereof is sputtered. The other end is connected to the electrode 14 and grounded. The high-frequency power applied to the sputter electrode 14 by the high-frequency power supply 16 is not particularly limited, and examples thereof include 13.65 MHz, maximum 5 kW, or maximum 1 kW high-frequency power, and the like, for example, 50 kHz to 2 MHz, It is preferable to use high frequency power of 27.12 MHz, 40.68 MHz, 60 MHz, 1 kW to 10 kW.

The sputter electrode 14 is discharged by applying high-frequency power (negative high-frequency) from the high-frequency power source 13 to turn a gas such as Ar introduced into the vacuum vessel 12 into plasma, thereby generating positive ions such as Ar ions. Therefore, the sputter electrode 14 can also be called a cathode electrode or a plasma electrode.
The positive ions generated in this way sputter the target material TG held on the sputter electrode 14. In this way, the constituent elements of the target material TG sputtered by the positive ions are released from the target material TG, and are neutralized or ionized on the substrate SB held by the substrate holders 18 that are arranged to face each other. Vapor deposited.
In this way, as will be described in detail later, a plasma space P containing positive ions such as Ar ions, constituent elements of the target material TG, ions thereof, and the like is formed in the vacuum vessel 12 as will be described in detail later.

The substrate holder 18 is disposed above the inside of the vacuum vessel 12 at a position facing the sputter electrode 14, and a constituent element (component) of the target material TG held by the sputter electrode 14 is deposited on the substrate holder 18. For holding the substrate SB on which a thin film such as is formed, that is, supporting the substrate SB from the upper surface in the figure. The substrate holder 18 is attached to the base 18a attached to the upper part inside the vacuum vessel 12, the substrate mounting base 18b attached to the base 18a and having an outer diameter larger than the outer diameter of the substrate SB, and the substrate mounting base 18b. And a plurality of L-shaped substrate holding members 18c whose front ends (lower ends in the figure) are bent inward so that the conductive surface SBa of the substrate SB faces the target material TG (sputter electrode 14). The conductive surface SBa of the substrate SB is placed on a portion (hereinafter referred to as an L-shaped portion) 18d that is bent into an L shape at the tip of the substrate holding member 18c.
The substrate holder 18 is not limited to the one that holds the substrate SB by the substrate holding member 18c, and may be one that electrostatically attracts the substrate SB by an electrostatic chuck or the like provided on the substrate mounting base 18b.

The substrate holder 18 (the substrate mounting base 18b) includes a heater (not shown) for heating and maintaining the substrate SB at a predetermined temperature during the formation of the substrate SB.
Here, in the sputtering apparatus 10 of the present invention, particularly when an insulating film is formed, the substrate SB is not at ground potential, and therefore the substrate SB held by the substrate holder 18 is at ground potential. It is preferable that the structure is not. That is, the sputtering apparatus 10 preferably has a structure in which the potential of the substrate SB, and thus the substrate holder 18, is a floating potential. Therefore, the base 18a of the substrate holder 18 is preferably insulative, particularly when an insulating film is formed. The substrate holding member 18c of the substrate holder 18 is preferably conductive.
The size of the substrate SB mounted on the substrate holder 18 is not particularly limited, and may be a normal 6-inch size substrate, a 5-inch or 8-inch size substrate, A substrate having a size of 5 cm square may be used.

The equipotential surface forming member (hereinafter also simply referred to as equipotential plate) 20 is the most characteristic part of the present invention, and is outside the L-shaped portion 18d at the tip of the substrate holding member 18c of the substrate holder 18, that is, A donut-shaped metal plate-like member attached to the target material TG (sputter electrode 14) side, which coincides with an inner envelope (envelope circle) of the substrate holding member 18c or is located outside the central opening 20b. The equipotential plate 20 has an equipotential surface 20a that is disposed or installed outside the substrate SB and on the side of the sputter electrode 14 and has the same potential as the conductive surface SBa of the substrate SB.
The equipotential plate 20 is not limited to that attached to the substrate holding member 18c of the substrate holder 18, but is directly attached to the substrate mounting base 18b and is in contact with or connected to the L-shaped portion 18d at the tip of the substrate holding member 18c. Alternatively, the substrate SB held by the substrate holding member 18c may be directly contacted or connected.
Further, when the equipotential plate 20 and the substrate SB are brought into direct contact, or when the three parties are brought into contact via the substrate holding member 18c of the substrate holder 18, the contact pressure is increased so as to reduce the influence of contact resistance. It is preferable to do this.
When the substrate holder 18 electrostatically attracts the substrate SB by an electrostatic chuck or the like provided on the substrate mounting base 18b, the equipotential plate 20 is directly attached to the substrate mounting base 18b and electrostatically attracted. The substrate SB may be configured to be in direct contact with or connected to the substrate SB, or may be directly attached to the electrostatically attracted substrate SB.

Here, the area of the equipotential surface 20a formed on the equipotential surface forming member 20 is preferably 40% or more, more preferably 70% of the area of the conductive surface SBa of the substrate SB that is equipotential. It is good that it is above, and most preferred is 150% or more.
The reason for this is, for example, as will be apparent from Experiment 1 described later, when the area ratio is 40% or more, it is more sure to be the lead zirconate titanate (PZT) having the perovskite structure than when there is no equipotential surface 20a. This is because it is possible to form a piezoelectric film, and as is clear from the ferroelectric hysteresis measurement in Experiments 4 and 5 to be described later, when the ratio is 70% or more, the ratio of the polarization value at the center and the end portion Is estimated to be 1.0, and it is considered that there is no change between the center and the end portion. Also, at 150% or more, as will be apparent from Experiments 2 to 5, particularly Experiment 5 described later. This is because the ratio of polarization values does not increase even when the number of film formations is repeated, and is estimated to be 1.0.

In the present invention, the conductive surface SBa of the substrate SB is formed on the outer side of the substrate SB and on the sputter electrode 14 side by forming an equipotential surface 20a having the same potential as the conductive surface SBa of the substrate SB. On top of this, there is no film quality variation or compositional deviation, and a high-quality insulating film or conductor film with excellent uniformity in film characteristics such as insulation characteristics and electrical characteristics, especially in-plane uniformity, is formed. be able to.
The reason for this is not completely understood, but can be considered as follows by the present inventors.
Here, in the sputtering apparatus 10 shown in FIG. 1, when the substrate SB is a conductive substrate and only the conductive substrate SB is installed and sputtered, the periphery of the substrate SB is not equipotential with the substrate SB. It is conceivable that the movement of ions such as Ar ⁺ causing discharge is greatly different.

On the other hand, as a problem in Patent Documents 4 and 5, when the difference between the plasma potential and the substrate potential is large, the Ar ⁺ collides with the film formed and causes reverse sputtering. Therefore, it is considered that the film formation rate is low where reverse sputtering is large, and the film formation rate is high where reverse sputtering is suppressed. Therefore, when there is a potential difference in the substrate plane, it is considered that the film thickness can be uneven. That is, what is solved in Patent Documents 4 and 5 is considered to be a problem of this uneven film thickness.
Even when an equipotential surface is provided, if the area is small or not sufficiently large, the effect is small even if it has an effect, and the movement of ions such as Ar ⁺ to the substrate surface is still small. However, it is thought that it is because the center and the edge are different. Therefore, in the present invention, the area of the equipotential surface 20a formed on the equipotential surface forming member 20 is preferably 40% or more of the area of the conductive surface SBa of the substrate SB that is equipotential. Preferably it is 70% or more, and most preferably 150% or more.

For example, when a piezoelectric film such as lead zirconate titanate (PZT) is formed, even if the difference in the substrate potential is different within the substrate plane even when the potential difference is such that the film thickness unevenness as described above is not possible, Since it is selectively sputtered from an element having a high sputtering rate such as lead, the amount of lead is considered to be different. For this reason, when no equipotential surface is provided around the substrate, the reverse sputtering is large and lead escape is large, so that the perovskite structure cannot be maintained and a pyrochlore structure is assumed.
On the other hand, even when equipotential surfaces are installed, especially when the area is small, the composition and crystal phase of the entire film are the same because lead depletion occurs at least in the initial stage of film formation. It is considered that there is a difference in electrical characteristics. Therefore, as described above, in the present invention, the area of the equipotential surface 20a formed on the equipotential surface forming member 20 is 40% or more of the area of the conductive surface SBa of the substrate SB that is equipotential. More preferably, it should be 70% or more, and most preferably 150% or more.

By the way, such a technique of the present invention controls the reverse sputtering by homogenizing the plasma of the sputtered film, so that it can be applied to any material.
However, continuity with the equipotential surface can be easily obtained when the material to be deposited is a metal or a conductor, and when the material to be deposited is an insulator, the equipotential surface must be considered for contact. It is more preferable to use it for materials such as insulators (insulators, dielectrics, ferroelectrics, piezoelectrics, pyroelectrics) because conduction cannot be easily achieved.

Even if it is not an insulator, in the case of a material whose composition changes remarkably by reverse sputtering, the in-plane distribution becomes large, so in the case of a substance containing a high sputtering rate, such as lead, bismuth or zinc. It is valid. For example, lead zirconate titanate (PZT) containing lead titanate or lead zirconate, its similar substances, PLZT, PT, etc., element substitutions thereof, bismuth-based dielectric called BLSF, multi-component such as BiFeO ₃ It can be more preferably applied to Zn-containing semiconductors such as ferroic materials, Bi-based superconductors, and IGZO.
In particular, when lead is removed, it can be preferably used for PZT-based materials that easily become a pyrochlore phase and lose ferroelectricity.

In addition, the deposition substrate used in the present invention has a conductive surface on at least one surface, and the above-described deposition material can be deposited on the one conductive surface. Any substrate may be used, for example, a conductive material such as a metal foil, a metal substrate, or a conductive ceramic substrate, a conductive substrate, an insulating substrate such as silicon, SiO ₂ , a glass substrate, or a ceramic substrate, or a semiconductive material. It is possible to use a substrate provided with conductivity on one side (one side) or both sides of the substrate, for example, a substrate in which a conductive material is formed on an insulating substrate or a semiconductive substrate, for example, as an electrode. it can. In other words, the present invention can be applied to a case where a film is formed on a conductor or a conductive substrate itself, or a case where a substrate formed using a conductive material as an electrode on an insulating substrate or a semiconductive substrate is used.

In the illustrated apparatus, the equipotential surface 20a of the equipotential surface forming member 20 is preferably arranged or placed on the side of the sputter electrode 14 with respect to the conductive surface SBa of the substrate SB that is equipotential.
The reason is that when the equipotential surface 20a of the equipotential surface forming member 20 is formed on the inner wall surface side of the vacuum chamber 12, the movement of ions such as Ar ⁺ toward the substrate surface is different between the center and the end. This is because it is considered.
The equipotential surface forming member 20 may be a single member or a plurality of members, and the equipotential surface 20a formed on the surface of the equipotential surface forming member 20 is: It may be a single surface or a plurality of surfaces with steps.

Here, the method of forming the equipotential surface 20a on the sputter electrode 14 side of the equipotential surface forming member 20 is not particularly limited as long as a surface having the same potential as the conductive surface SBa of the substrate SB can be formed. For example, at least a part of the L-shaped part 18d at the front end of the substrate holding member 18c of the substrate holder 18, for example, the entire L-shaped part 18d at the front end or a part of the L-shaped part 18d at the front end. The conductive surface SBa of the substrate SB is electrically connected to the metal equipotential plate 20 via the L-shaped portion 18d at the conductive tip of the substrate holding member 18c. Alternatively, when the L-shaped portion 18d at the tip of the substrate holding member 18c is not conductive, the equipotential plate 20 is attached to the substrate holding member 18c of the substrate holder 18 and inside the substrate holding member 18c. The Te equipotential plate 20 contacting the conductive surface SBa of the substrate SB, or electrically connected, it may be caused to conduct.
In the present invention, since the equipotential surface 20a of the equipotential plate 20 and the conductive surface SBa of the substrate SB are equipotential, the two are made conductive when both surfaces are brought into contact with each other. When connected by a conductive member, or when the equipotential plate 20 and the substrate SB are connected by a conductive member, the resistance between both surfaces is several Ω, that is, 10Ω or less, preferably 5Ω or less, more preferably Means 1Ω or less.

Further, in the illustrated sputtering apparatus 10, if an insulating film adheres to the equipotential surface 20 a of the equipotential surface forming member 20, or if film formation is repeated, the equipotential installed in the vacuum chamber 12. If the insulating film adheres to the equipotential surface 20a of the plate 20, the function of the equipotential surface 20a of the equipotential plate 20 decreases as the equipotential surface. If the insulating film increases in thickness, it functions as the equipotential surface. It will disappear.
Therefore, in the present invention, the equipotential plate 20 preferably has a thickness of the insulating film attached to the equipotential surface 20a of 10 μm or less, more preferably 6 μm or less, and still more preferably. Is preferably 4 μm or less, and most preferably a member having no insulating film attached to the equipotential surface 20a.
This is because, as will be apparent from Experiment 5 to be described later, if the number of film formation is repeated and the thickness of the insulating film exceeds 10 μm, the equipotential surface 20a will not function as an equipotential surface.

  Here, in the sputtering method and sputtering apparatus of the present invention, the thickness of the insulating film attached to the equipotential surface 20a of the equipotential surface forming member 20 installed in the vacuum chamber 12 when the number of film formations is repeated. As a result, the equipotential surface 20a of the equipotential plate 20 does not function as an equipotential surface, and a high-quality insulating film cannot be formed, resulting in poor yield. For this reason, while the thickness of the insulating film adhering to the equipotential surface 20a of the equipotential surface forming member 20 installed in the vacuum chamber 12 is 0 or 10 μm or less, that is, not exceeding 10 μm, A thin film is preferably formed on the conductive surface SBa of the film formation substrate SB. The thickness of the insulating film on the equipotential surface 20a is more preferably 6 μm or less, more preferably 4 μm or less, and most preferably 0.

The sputtering apparatus of the present invention is basically configured as described above, and its operation and the sputtering method of the present invention will be described below.
FIG. 2 is a flowchart showing an example of the sputtering method of the present invention.
First, as shown in FIG. 2, in step S10, in the sputtering apparatus 10 shown in FIG. 1, a sputtering target material TG is mounted and held on the sputtering electrode 14 provided in the vacuum vessel 12, and the vacuum vessel A substrate SB having a conductive surface SBa on which a thin film such as a piezoelectric film is formed is mounted on a substrate holder 18, which is disposed at a position facing the sputter electrode 14 and is mounted with an equipotential surface forming member 20. And hold it.
At this time, as step S12, the equipotential of the equipotential plate 20 attached to the conductive surface SBa of the substrate SB mounted on the substrate holder 18 and the L-shaped portion 18d of the tip of the substrate holding member 18c of the substrate holder 18 is obtained. The surface 20a is measured by a tester or the like to confirm that it is conductive. Note that steps S10 and S12 may be performed simultaneously, or conversely, step S12 may be performed first and step S10 may be performed later.

Thereafter, in step S14, the gas discharge pipe 12b is evacuated until the inside of the vacuum vessel 12 reaches a predetermined degree of vacuum, and the argon gas (Ar The plasma gas such as) is continuously supplied in a predetermined amount. At the same time, in step S16, a high frequency (negative high frequency power) is applied to the sputter electrode 14 from the high frequency power supply 16 to discharge the sputter electrode 14, and a gas such as Ar introduced into the vacuum vessel 12 is plasma. Then, positive ions such as Ar ions are generated, and the plasma space P is formed.
Next, in step S18, the positive ions in the plasma space P thus formed sputter the target material TG held by the sputter electrode 14, and the constituent elements of the sputtered target material TG are released from the target material TG. In a neutral or ionized state, vapor deposition is performed on the substrate SB held by the substrate holders 18 arranged to face each other, and film formation is started.

By controlling the plasma energy during film formation and maintaining the substrate potential at a predetermined floating potential, it is possible to improve the quality of the film by preventing reverse sputtering, control the composition deviation, and improve the reproducibility of the film formation. It is possible to form a thin film such as a high-quality piezoelectric film having a certain quality, that is, a high-quality piezoelectric film having no change in film quality (step S20).
In the present invention, when the film formation from step S10 to step S20 is repeated, the thickness of the thin film formed on the conductive surface SBa of the substrate SB is considered in one film formation. Furthermore, it is necessary to repeat so that the thickness of the thin film formed on the equipotential surface 20a of the equipotential plate 20 does not exceed 10 μm. At this time, if it can be confirmed that the thickness of the thin film formed on the equipotential surface 20a of the equipotential plate 20 does not exceed 10 μm during the film formation, it is equipotential with the conductive surface SBa of the substrate SB in step S12. Confirmation of conduction with the equipotential surface 20a of the plate 20 may not be performed.

Next, other preferable film forming conditions in the film forming method by the sputtering method of the present invention will be described.
The film forming conditions in the film forming method by sputtering of the present invention are the difference between the film forming temperature Ts (° C.) and the plasma potential Vs (V) in the plasma during film formation and the floating potential Vf (V) of the substrate. It is preferably determined based on the relationship between Vs−Vf (V) and the characteristics of the film to be formed.
Here, the characteristics of the film for which the relationship is required include the crystal structure and / or film composition of the film.

FIG. 3 is an explanatory view schematically showing a state during film formation in the sputtering apparatus shown in FIG.
As schematically shown in FIG. 3, the gas introduced into the vacuum vessel 12 by the discharge of the sputter electrode 14 is turned into plasma, and positive ions Ip such as Ar ions are generated, and the sputter electrode 14 and the substrate holder 18 are In other words, a plasma space P is generated between the target material TG held by the sputter electrode 14 and the substrate SB held by the substrate holder 18. The generated positive ions Ip sputter the target material TG. The constituent element Tp of the target material TG sputtered by the positive ions Ip is emitted from the target material TG and deposited on the substrate SB in a neutral or ionized state.
At this time, since the equipotential plate 20 is attached to the conductive surface SBa on the outside of the substrate SB and on the target material TG side so as to be electrically connected to the substrate SB, the conductivity of the positive ions Ip in the vacuum vessel 12 Since the movement toward the surface SBa does not change at the center or the end of the conductive surface SBa of the substrate SB, the constituent element Tp of the target material TG released from the target material TG is neutralized or ionized on the conductive surface SBa. Evaporate evenly at the center and at the edges. For this reason, it is thought that the vapor deposition thin film obtained becomes a high quality film with uniform film quality.

  The potential of the plasma space P becomes the plasma potential Vs (V). In the present invention, the substrate SB is normally an insulator and is electrically insulated from the ground. Therefore, the substrate SB is in a floating state, and the potential thereof is the floating potential Vf (V). The constituent element Tp of the target material TG between the target material TG and the substrate SB has a kinetic energy corresponding to the acceleration voltage Vs−Vf between the potential of the plasma space P and the potential of the substrate SB. It is thought that it collides with the substrate SB.

The plasma potential Vs and the floating potential Vf can be measured using a Langmuir probe. When the tip of a Langmuir probe is inserted into the plasma P and the voltage applied to the probe is changed, for example, current-voltage characteristics as shown in FIG. 4 can be obtained (Mitsuharu Onuma, “Plasma and Film Formation Basics” p. .90, published by Nikkan Kogyo Shimbun). In FIG. 4, the probe potential at which the current becomes 0 is the floating potential Vf. This state is that the ion current and the electron current flow into the probe surface become equal. The surface of the metal in the insulating state and the surface of the substrate are at this potential. As the probe voltage is made higher than the floating potential Vf, the ionic current gradually decreases, and only the electron current reaches the probe. The voltage at this boundary is the plasma potential Vs.
The potential difference Vs−Vf between the plasma space P and the substrate SB can be changed by installing a ground between the substrate SB and the target material TG, but the floating potential Vf that is the substrate potential of the substrate SB is adjusted. It can also be changed.

In sputtering using plasma, factors that influence the characteristics of the film to be formed include the film formation temperature, the type of substrate, the composition of the substrate, the surface energy of the substrate, and the composition, if there is a film previously formed on the substrate. The film pressure, the amount of oxygen in the atmospheric gas, the input electrode, the distance between the substrate and the target, the electron temperature and electron density in the plasma, the active species density in the plasma and the lifetime of the active species are considered.
The present inventors have found that, among various film formation factors, the characteristics of the film to be formed largely depend on two factors of the film formation temperature Ts and the potential difference Vs−Vf. It has been found that a high-quality film can be formed by making it easier. That is, it has been found that when the film formation temperature Ts is plotted on the horizontal axis and the potential difference Vs−Vf is plotted on the vertical axis and the film characteristics are plotted, a good film can be formed within a certain range (see FIG. 5).

It has been described that the potential difference Vs−Vf correlates with the kinetic energy of the constituent element Tp of the target material TG colliding with the substrate SB. Since the kinetic energy E is generally expressed as a function of the temperature T as shown in the following equation, it is considered that the potential difference Vs−Vf has the same effect as the temperature with respect to the substrate SB.
E = 1 / 2mv ² = 3 / 2kT
(Where m is mass, v is velocity, k is a constant, and T is absolute temperature.)
The potential difference Vs−Vf is considered to have effects such as an effect of promoting surface migration and an effect of etching a weakly coupled portion in addition to the effect similar to the temperature.

  Japanese Patent Application Laid-Open No. 2004-119703 proposes that a bias is applied to the substrate in order to relieve the tensile stress applied to the piezoelectric film when the piezoelectric film is formed by sputtering. Applying a bias to the substrate changes the energy amount of the constituent element of the target that enters the substrate. However, Japanese Patent Application Laid-Open No. 2004-119703 does not describe the plasma potential Vs and the potential difference Vs−Vf that is the difference between the plasma potential Vs and the floating potential Vf.

  Usually, in a film forming apparatus such as a conventional sputtering apparatus, the potential difference Vs−Vf between the plasma space P and the substrate SB is substantially determined by the structure of the apparatus and cannot be changed greatly. Conventionally, the potential difference Vs−Vf is changed. There was almost no idea itself. Although not a sputtering method, Japanese Patent Application Laid-Open No. 10-60653 discloses a film forming method for controlling an electric potential difference Vs−Vf within a specific range in a film forming method for forming an amorphous silicon film or the like by a high frequency plasma CVD method. Has been. In the present invention, the potential difference Vs−Vf is controlled within a specific range in order to eliminate the potential difference Vs−Vf becoming non-uniform on the substrate surface. However, Japanese Patent Application Laid-Open No. 10-60653 does not describe determining film forming conditions based on the relationship between the film forming temperature Ts, Vs−Vf, and the characteristics of the film to be formed.

Such a film forming method can be applied to any film as long as it can be formed by a vapor phase growth method using plasma including the sputtering method of the present invention. Examples of the film to which the sputtering method of the present invention and such a film forming method can be applied include an insulating film, a dielectric film, and a piezoelectric film.
Such a film formation method can be preferably applied to film formation of a piezoelectric film (which may contain inevitable impurities) made of one or more kinds of perovskite oxides. A piezoelectric film made of a perovskite oxide is a ferroelectric film having spontaneous polarization when no voltage is applied.

When the present inventors apply such a film formation method to a piezoelectric film made of one or more perovskite oxides represented by the following general formula (P), the following formulas (1) and (2) It has been found that it is preferable to determine the film forming conditions within a range that satisfies the above (see FIG. 5).
General formula A _a B _b O ₃ (P)
(In the formula, A: A site element, at least one element including Pb, B: B site element, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Sc, At least one element selected from the group consisting of Co, Cu, In, Sn, Ga, Zn, Cd, Fe, Ni, and a lanthanide element, O: oxygen atom, a = 1.0 and b = 1.0 Is a standard, but these values may deviate from 1.0 within a range where a perovskite structure can be taken).
Ts (° C.) ≧ 400 (1),
−0.2Ts + 100 <Vs−Vf (V) <− 0.2Ts + 130 (2)

  Examples of the perovskite oxide represented by the general formula (P) include lead titanate, lead zirconate titanate (PZT), lead zirconate, lead lanthanum titanate, lead lanthanum zirconate titanate, zirconium magnesium niobate Lead-containing compounds such as lead titanate, lead nickel niobate and zirconium titanate, and non-lead-containing compounds such as barium titanate, sodium bismuth titanate, potassium bismuth titanate, sodium niobate, potassium niobate, lithium niobate Is mentioned. The piezoelectric film may be a mixed crystal system of perovskite oxides represented by the above general formula (P).

The sputtering method of the present invention can be preferably applied to PZT represented by the following general formula (P-1) or a B site substitution system thereof, and a mixed crystal system thereof.
Pb _a (Zr _b1 Ti _b2 X _b3 ) O ₃ (P-1)
(In Formula (P-1), X is at least one metal element selected from the group of elements of Group V and Group VI. A> 0, b1> 0, b2> 0, b3 ≧ 0. A = 1.0 and b1 + b2 + b3 = 1.0 is standard, but these values may deviate from 1.0 within a range where a perovskite structure can be taken.)
The perovskite oxide represented by the general formula (P-1) is lead zirconate titanate (PZT) when d = 0, and when d> 0, part of the B site of PZT is group V. And an oxide substituted with X which is at least one metal element selected from the group of elements of group VI.
X may be any metal element of Group VA, Group VB, Group VIA, and Group VIB, and is preferably at least one selected from the group consisting of V, Nb, Ta, Cr, Mo, and W. .

When forming a piezoelectric film made of a perovskite oxide represented by the above general formula (P), the present inventors have Ts (° C.) <400 that does not satisfy the above formula (1). It has been found that the film formation temperature is too low and the perovskite crystal does not grow well, and a main film with a pyrochlore phase is formed (see FIG. 5).
Further, when forming a piezoelectric film made of a perovskite oxide represented by the general formula (P), the present inventors satisfy the above formula (1) under the condition of Ts (° C.) ≧ 400. By determining the film forming conditions within a range where the film forming temperature Ts and the potential difference Vs−Vf satisfy the above formula (2), it is possible to stably grow a perovskite crystal having a small pyrochlore phase, and to eliminate Pb loss. It has been found that a high-quality piezoelectric film that can be stably suppressed and has a good crystal structure and film composition can be stably formed (see FIG. 5).

  In sputter deposition of PZT, it is known that Pb loss is likely to occur when the film is deposited at a high temperature (see, for example, FIG. 2 of JP-A-6-49638). The present inventors have found that Pb loss depends not only on the film formation temperature but also on the potential difference Vs−Vf. Of Pb, Zr, and Ti, which are constituent elements of PZT, Pb has the largest sputtering rate and is easily sputtered. For example, in Table 8.1.7 of “Vacuum Handbook” (published by ULVAC, Inc., published by Ohm), the sputtering rate under the conditions of Ar ion 300 ev is Pb = 0.75, Zr = 0.48, Ti = 0.65. Easily sputtered means that the sputtered atoms are likely to be re-sputtered after adhering to the substrate surface. It is considered that the greater the difference between the plasma potential and the substrate potential, that is, the greater the difference in Vs−Vf, the higher the resputtering rate and the more likely Pb loss occurs. The same applies to Pb-containing perovskite oxides other than PZT. The same applies to vapor phase growth methods using plasma other than sputtering.

If the film forming temperature Ts and the potential difference Vs−Vf are both too low, the perovskite crystal tends to be unable to grow well. Moreover, when at least one of the film forming temperature Ts and the potential difference Vs−Vf is excessive, Pb loss tends to occur.
That is, under the condition of Ts (° C.) ≧ 400 that satisfies the above formula (1), when the film formation temperature Ts is relatively low, the potential difference Vs−Vf is relatively set to grow the perovskite crystal satisfactorily. When the film formation temperature Ts is relatively high, the potential difference Vs−Vf needs to be relatively low in order to suppress Pb loss. This is represented by the above formula (2).

When forming a piezoelectric film made of a perovskite oxide represented by the general formula (P), the present inventors determine film forming conditions within a range satisfying the following expressions (1) to (3). Thus, it has been found that a piezoelectric film having a high piezoelectric constant can be obtained.
Ts (° C.) ≧ 400 (1),
−0.2Ts + 100 <Vs−Vf (V) <− 0.2Ts + 130 (2),
10 ≦ Vs−Vf (V) ≦ 35 (3)

When the present inventors form a piezoelectric film made of the perovskite oxide represented by the general formula (P), the potential difference Vs−Vf (V) under the condition of film formation temperature Ts (° C.) = About 420. ) = About 42 V, it is possible to grow a perovskite crystal without Pb loss, but the piezoelectric constant d ₃₁ of the obtained film has been found to be as low as about 100 pm / V. Under this condition, it is considered that the potential difference Vs−Vf, that is, the energy of the constituent element Tp of the target material TG colliding with the substrate is too high, so that the film is likely to be defective and the piezoelectric constant is lowered. The present inventors have found that a piezoelectric film having a piezoelectric constant d ₃₁ ≧ 130 pm / V can be formed by determining the film forming conditions within a range that satisfies the above formulas (1) to (3).

In the vapor phase growth method using plasma such as the sputtering method of the present invention, factors affecting the film characteristics are the film formation temperature Ts (° C.) and the plasma potential Vs (V) in the plasma during film formation. And the potential difference Vs−Vf (V), which is the difference between the floating potential Vf (V).
According to the film formation method such as the sputtering method of the present invention, the film formation conditions are determined based on the relationship between the above two factors affecting the film characteristics and the characteristics of the film to be formed. Therefore, a high-quality film can be stably formed by a vapor phase growth method using plasma such as a sputtering method.
By adopting the film forming method according to the present invention, it is possible to easily find a condition for forming a high-quality film even if the apparatus conditions are changed, and it is possible to stably form a high-quality film.

  The film formation method by the sputtering method of the present invention can be preferably applied to the formation of a piezoelectric film or the like. According to the present invention, it is possible to stably grow a perovskite crystal having a small pyrochlore phase in the formation of a piezoelectric film made of a perovskite oxide. According to the present invention, in the formation of a piezoelectric film made of a Pb-containing perovskite oxide such as PZT, it is possible to stably grow a perovskite crystal having a small pyrochlore phase and to stably suppress Pb loss. Is possible.

By applying the film forming method, the following piezoelectric film can be provided.
That is, this piezoelectric film is formed by a vapor phase growth method using plasma, such as the sputtering method of the present invention, in a piezoelectric film made of one or more perovskite oxides represented by the following general formula (P). The film was formed under film forming conditions satisfying the following formulas (1) and (2).
General formula A _a B _b O ₃ (P)
(In the formula, A: A site element, at least one element including Pb, B: B site element, Ti, Zr, V, Nb, Ta, Cr, Mo, W, Mn, Sc, At least one element selected from the group consisting of Co, Cu, In, Sn, Ga, Zn, Cd, Fe, Ni, and a lanthanide element, O: oxygen atom, a = 1.0 and b = 1.0 Is a standard, but these values may deviate from 1.0 within a range where a perovskite structure can be taken).
Ts (° C.) ≧ 400 (1),
−0.2Ts + 100 <Vs−Vf (V) <− 0.2Ts + 130 (2)

According to the present invention, it is possible to stably provide a high-quality piezoelectric film having a perovskite crystal structure with a small pyrochlore phase, further suppressing Pb loss, and having a good crystal structure and film composition.
In addition, according to the present invention, it is possible to provide a piezoelectric film having a composition with 1.0 ≦ a and without Pb loss, and it is also possible to provide a piezoelectric film having a Pb-rich composition with 1.0 <a. . The upper limit of a is not particularly limited, and the present inventors have found that a piezoelectric film having good piezoelectric performance can be obtained when 1.0 ≦ a ≦ 1.3.

The piezoelectric film according to the present invention is preferably formed under film forming conditions satisfying the following formulas (1) to (3). With such a configuration, a piezoelectric film having a high piezoelectric constant can be provided.
Ts (° C.) ≧ 400 (1),
−0.2Ts + 100 <Vs−Vf (V) <− 0.2Ts + 130 (2),
10 ≦ Vs−Vf (V) ≦ 35 (3)

The piezoelectric film according to the present invention thus obtained is composed of a high-quality insulating film or dielectric film having no film quality variation or composition deviation, in particular, a Pb-containing perovskite oxide such as PZT, and a perovskite crystal having a small pyrochlore phase. It is a piezoelectric film that is stably grown and Pb loss is stably suppressed, and can be used as a piezoelectric element suitable for use in an inkjet head or the like.
The thin films such as piezoelectric films, insulating films, and dielectric films obtained by the present invention are basically configured as described above.

Next, the structure of the piezoelectric element and the ink jet head including the piezoelectric element will be described. FIG. 6 is a sectional view (a sectional view in the thickness direction of the piezoelectric element) of an embodiment of an inkjet head using an embodiment of a piezoelectric element. In order to facilitate visual recognition, the scale of the constituent elements is appropriately changed from the actual one.
As shown in FIG. 6, the inkjet head 50 includes a piezoelectric element 52, an ink storage / discharge member 54, and a diaphragm 56 provided between the piezoelectric element 52 and the ink storage / discharge member 54.
First, the piezoelectric element will be described. As shown in the figure, the piezoelectric element 52 is an element comprising a substrate 58 and a lower electrode 60, a piezoelectric film 62 and an upper electrode 64 that are sequentially laminated on the substrate 58. An electric field is applied in the thickness direction by the electrode 60 and the upper electrode 64.

The substrate 58 is not particularly limited, and examples thereof include silicon, glass, stainless steel (SUS), yttrium stabilized zirconia (YSZ), alumina, sapphire, silicon carbide, and the like. As the substrate 58, a laminated substrate such as an SOI substrate in which a SiO ₂ oxide film is formed on the surface of a silicon substrate may be used.
The lower electrode 60 is formed on substantially the entire surface of the substrate 58, and a piezoelectric film 62 having a pattern in which line-shaped convex portions 62a extending from the front side to the back side in the drawing are arranged in a stripe shape is formed thereon. The upper electrode 64 is formed on each convex portion 62a.
The pattern of the piezoelectric film 62 is not limited to that shown in the figure, and is designed as appropriate. The piezoelectric film 62 may be a continuous film, but the piezoelectric film 62 is not a continuous film, but is formed by a pattern made up of a plurality of protrusions 62a separated from each other, so that each protrusion 62a can be expanded and contracted smoothly. Therefore, a larger amount of displacement is obtained, which is preferable.

The main component of the lower electrode 60 is not particularly limited, and examples thereof include metals or metal oxides such as Au, Pt, Ir, IrO ₂ , RuO ₂ , LaNiO ₃ , and SrRuO ₃ , and combinations thereof.
The main component of the upper electrode 64 is not particularly limited, and the materials exemplified in the lower electrode 60, electrode materials generally used in semiconductor processes such as Al, Ta, Cr, and Cu, and combinations thereof Is mentioned.
The piezoelectric film 62 is a film formed by a film forming method to which the above-described sputtering method of the present invention is applied. The piezoelectric film 62 is preferably a piezoelectric film made of a perovskite oxide represented by the general formula (P).
The thickness of the lower electrode 60 and the upper electrode 64 is, for example, about 200 nm. The film thickness of the piezoelectric film 62 is not particularly limited and is usually 1 μm or more, for example, 1 to 5 μm.

An ink jet head 50 shown in FIG. 6 is roughly external to an ink chamber (ink storage chamber) 68 in which ink is stored and an ink chamber 68 on the lower surface of the substrate 58 of the piezoelectric element 52 having the above-described configuration. An ink storing and discharging member 54 having an ink discharge port (nozzle) 70 through which ink is discharged is attached. A plurality of ink chambers 68 are provided corresponding to the number and pattern of convex portions 62 a of the piezoelectric film 62. That is, the inkjet head 50 has a plurality of ejection units 72, and the piezoelectric film 62, the upper electrode 64, the ink chamber 68, and the ink nozzle 70 are provided for each ejection unit 72. On the other hand, the lower electrode 60, the substrate 58, and the diaphragm 56 are provided in common for the plurality of ejection units, but are not limited thereto, and may be provided individually or in groups.
In the ink jet head 50, the electric field strength applied to the convex portion 62a of the piezoelectric element 52 is increased or decreased for each convex portion 62a by a preferable driving method described later or a conventionally known driving method, thereby expanding and contracting the ink chamber. The ink is discharged from 68 and the discharge amount is controlled.
The piezoelectric element of this embodiment and the ink jet head using the same are basically configured as described above.

Next, the structure of an ink jet recording apparatus including the ink jet head according to the present invention will be described. FIG. 7 is an overall view of an apparatus showing an overall configuration of an embodiment of an ink jet recording apparatus provided with an ink jet head according to the present invention, and FIG. 8 is a partial top view thereof.
The illustrated ink jet recording apparatus 100 includes a printing unit 102 having a plurality of ink jet heads (hereinafter simply referred to as “heads”) 50K, 50C, 50M, and 50Y provided for each ink color, and the heads 50K and 50C. , 50M, 50Y, an ink storage / loading unit 114 that stores ink to be supplied, a paper feeding unit 118 that supplies recording paper 116, a decurling unit 120 that removes curling of the recording paper 116, and a printing unit 102. A suction belt conveyance unit 122 that conveys the recording paper 116 while maintaining the flatness of the recording paper 116, and a print detection unit 124 that reads a printing result by the printing unit 102. And a paper discharge unit 126 that discharges printed recording paper (printed matter) to the outside.

The heads 50K, 50C, 50M, and 50Y forming the printing unit 102 are the inkjet heads 50 (see FIG. 6) of the above-described embodiment.
In the decurling unit 120, heat is applied to the recording paper 116 by the heating drum 130 in the direction opposite to the curl direction, and the decurling process is performed.
In the apparatus using roll paper, as shown in FIG. 7, a cutter 128 is provided at the subsequent stage of the decurling unit 120, and the roll paper is cut into a desired size by this cutter. The cutter 128 includes a fixed blade 128A having a length equal to or greater than the conveyance path width of the recording paper 116 and a round blade 128B that moves along the fixed blade 128A. The fixed blade 128A is provided on the back side of the print. The round blade 128B is arranged on the print surface side with the conveyance path interposed therebetween. In an apparatus using cut paper, the cutter 128 is unnecessary.

The decurled and cut recording paper 116 is sent to the suction belt conveyance unit 122. The suction belt conveyance unit 122 has a structure in which an endless belt 133 is wound between rollers 131 and 132, and at least portions facing the nozzle surface of the printing unit 102 and the sensor surface of the printing detection unit 124 are horizontal ( Flat surface).
The belt 133 has a width that is wider than the width of the recording paper 116, and a plurality of suction holes (not shown) are formed on the belt surface. An adsorption chamber 134 is provided at a position facing the nozzle surface of the print unit 102 and the sensor surface of the print detection unit 124 inside the belt 133 that is stretched between the rollers 131 and 132. The recording paper 116 on the belt 133 is sucked and held by suctioning at 135 to make a negative pressure.

The power of a motor (not shown) is transmitted to at least one of the rollers 131 and 132 around which the belt 133 is wound, so that the belt 133 is driven in the clockwise direction in FIG. 7 and is held on the belt 133. The recording paper 116 is conveyed from left to right in FIG.
Note that when a borderless print or the like is printed, the ink also adheres to the belt 133. Therefore, the belt cleaning unit 136 is provided at a predetermined position outside the belt 133 (an appropriate position other than the print region).
In addition, a heating fan 140 is provided on the upstream side of the printing unit 102 on the paper conveyance path formed by the suction belt conveyance unit 122. The heating fan 140 heats the recording paper 116 by blowing heated air onto the recording paper 116 before printing. Heating the recording paper 116 immediately before printing makes it easier for the ink to dry after landing.

The printing unit 102 is a so-called full-line head in which line-type heads having a length corresponding to the maximum paper width are arranged in a direction (main scanning direction) orthogonal to the paper feed direction (see FIG. 8). Each of the print heads 50K, 50C, 50M, and 50Y is a line-type head in which a plurality of ink discharge ports (nozzles) are arranged over a length that exceeds at least one side of the maximum size recording paper 116 targeted by the ink jet recording apparatus 100. It is configured.
Heads 50K, 50C, 50M, and 50Y corresponding to the respective color inks are arranged in the order of black (K), cyan (C), magenta (M), and yellow (Y) from the upstream side along the feeding direction of the recording paper 116. ing. A color image is recorded on the recording paper 116 by discharging the color ink from the heads 50K, 50C, 50M, and 50Y while conveying the recording paper 116.

The print detection unit 124 includes a line sensor that images the droplet ejection result of the print unit 102 and detects ejection defects such as nozzle clogging from the droplet ejection image read by the line sensor.
A post-drying unit 142 including a heating fan or the like for drying the printed image surface is provided at the subsequent stage of the print detection unit 124. Since it is preferable to avoid contact with the printing surface until the ink after printing is dried, a method of blowing hot air is preferred.
A heating / pressurizing unit 144 is provided downstream of the post-drying unit 142 in order to control the glossiness of the image surface. The heating / pressurizing unit 144 presses the image surface with a pressure roller 145 having a predetermined surface irregularity shape while heating the image surface, and transfers the irregular shape to the image surface.

The printed matter obtained in this manner is outputted from the paper output unit 126. It is preferable that the original image to be printed (printed target image) and the test print are discharged separately. In the ink jet recording apparatus 100, there is provided sorting means (not shown) for switching the paper discharge path in order to select the print product of the main image and the print product of the test print and send them to the discharge units 126A and 126B. It has been.
When the main image and the test print are simultaneously printed on a large sheet of paper, the cutter 148 may be provided to separate the test print portion.
The ink jet recording apparatus of this embodiment is basically configured as described above.

  The sputtering method and apparatus according to the present invention have been described in detail with reference to various embodiments and examples. However, the present invention is not limited to the above-described embodiments and examples, and does not depart from the gist of the present invention. Of course, various improvements and design changes may be made within the scope.

The present invention will be specifically described below based on examples.
(Experiment 1)
A sputtering apparatus manufactured by ULVAC is used as the sputtering apparatus 10 shown in FIG. 1, a sintered body target having a composition of Pb _1.3 Zr _0.52 Ti _0.48 O _x is used as the target material TG, and the film formation temperature is set. A PZT film was formed at 450 ° C. As the film formation substrate SB, as shown in FIG. 9, a 3 inch, 625 μm thick silicon substrate 38 in which Ti (Ti layer 34) is laminated to 20 nm and Ir (Ir layer 36) is laminated to 150 nm is used as the electrode 32. Note that the SiO ₂ layer 4 was formed on the surface of the silicon substrate 38. Further, as shown in FIG. 9, the film thickness of the PZT film 42 formed on the surface (SBa) of the Ir layer (electrode) 36 of the electrode 32 of the film formation substrate SB was 4 μm.

Example 1
As schematically shown in FIG. 10A, a 3 inch (76.2 mm) silicon substrate 38 with electrodes 32 (film formation substrate SB) is used as an equipotential surface forming member 20 and an Inconel plate 22 having an outer diameter of 90 mm. It was supported by (film formation jig). With a tester, the resistance between the surface of the Ir electrode 36 (conductive surface SBa) of the substrate SB and the surface of the Inconel plate 22 (equipotential surface 20a of the equipotential plate 20) is measured, and the measured resistance is 1Ω. The following was shown, and it was confirmed that the Ir electrode surface SBa of the substrate SB and the surface 22a (equipotential surface 20a) of the Inconel plate 22 (equipotential plate 20) were electrically connected. Film formation was performed in this state.

(Comparative Example 1)
As schematically shown in FIG. 10B, in Example 1, alumina is coated on the back surface (substrate SB side) of the inconel plate 22 having an outer diameter of 90 mm used as the equipotential plate 20, and the insulating layer 24 is formed. Then, the substrate SB used in Example 1 was set on the insulating layer 24. When the resistance between the Ir electrode surface SBa of the substrate SB and the surface 22a of the Inconel plate 22 was measured by a tester, the resistance was 1 GΩ or more, and conduction was not confirmed by the tester. That is, it was confirmed that the Inconel plate 22 did not function as the equipotential plate 20. In this state, film formation was performed in the same manner.

(Result of Experiment 1)
In Example 1, it was confirmed by XRD (X-ray diffractometer) that a perovskite phase lead zirconate titanate (PZT) film (PZT film 42) was formed.
In Comparative Example 1, the formed film became a pyrochlore phase, and the target lead zirconate titanate film was not obtained. As a result of measuring the film composition with XRF (fluorescence X-ray analyzer), the lead amount (Pb / (Zr + Ti)) was 1.05 in Example 1, but 0.8 in the comparative example, If the present invention is not used, it has been found that the plasma during film formation concentrates on the substrate SB, so that Pb is lost, Pb is insufficient, and a desired film cannot be formed. In the XRF measurement, a fundamental parameter (FP) method was used in order to eliminate the influence of iridium (Ir) of the Ir layer 36 of the lower electrode 32.
These results are shown in Table 1.
The ratio of the conductive area in the table was obtained by dividing the area of only the equipotential surface 20a of the equipotential plate 20 by the conductive surface SBa of the film formation substrate SB. That is, when the 90 mm inconel plate 22 is the equipotential plate 20, the ratio of the conductive area is calculated as (90 ² -76.2 ² ) /76.2 ² (= 40%), and the 90 mm inconel plate 22 is obtained. And the 120 mm inconel plate 26 is the equipotential plate 20, it was calculated as (120 ² −76.2 ² ) /76.2 ² (= 150%).

(Experiment 2)
In Experiment 1, with the aim of further improving the uniformity, an Inconel plate 26 with an outer diameter of 120 mm was installed outside the Inconel plate 22 with an outer diameter of 90 mm used as the equipotential plate 20.
(Example 2)
As schematically shown in FIG. 11, an insulating washer 28 is sandwiched between the Inconel plate 22 (equipotential plate 20) and the Inconel plate 26, and the Inconel plate 26 is installed. The film was formed in an electrically floating state with the surface SBa).
As in Experiment 1, the continuity was confirmed by a tester, and the electrode (conductive surface SBa) of the substrate SB was conductive up to the surface 22a (equipotential surface 20a) of the Inconel plate 22 (equipotential plate 20). It was confirmed that the Inconel plate 26 was not conductive. That is, it was confirmed that the Inconel plate 26 does not function as the equipotential plate 20.

(Example 3)
As schematically shown in FIG. 12, a conductive washer 30 is sandwiched between a 90 mm inconel plate 22 and a 120 mm inconel plate 26, and an electrode (conductive surface SBa) of the substrate SB and the inconel plate 26 The gaps were made conductive so that they were equipotential. As in Experiment 1, it was confirmed with a tester, and it was confirmed that conduction was made from the electrode (conductive surface SBa) of the substrate SB to the surface 26a of the Inconel plate 26. That is, the Inconel plate 22 and the Inconel plate 26 constitute the equipotential plate 20, and the surface 22a of the Inconel plate 22 and the surface 26a of the Inconel plate 26 constitute the equipotential surface 20a.
In any of Examples 1 to 3, it was confirmed by XRD that the single-phase perovskite film (PZT film 42) was on the entire surface, and composition analysis by XRF confirmed that all were 1.05. did.
The results are shown in Table 1.

  As is clear from the results in Table 1, in any of Examples 1 to 3, since the equipotential surface 20a was installed outside the film formation substrate SB, it can be seen that a perovskite single phase film was obtained. In any of the methods of Examples 1 to 3, it was found that the present invention is effective for producing a high-quality lead zirconate titanate film (PZT film 42).

Next, an upper electrode was formed on the PZT film 42 of the substrate SB obtained in Examples 1 to 3, a voltage was applied between the lower electrode and the upper electrode, and ferroelectric hysteresis measurement was measured.
As shown in FIG. 13, the ferroelectric hysteresis measurement has three measurement positions: a center position of a 3-inch (76.2 mm) substrate SB (PZT film 42), a position 20 mm from the center, and a position 35 mm from the center. did.
The measurement results of the ferroelectric hysteresis of the PZT film 42 obtained in Examples 1 and 3 are shown in FIGS. 14 and 15, respectively.
As shown in FIGS. 14 and 15, it was found that there was a difference in the ferroelectric hysteresis measurement in Example 1 and Example 3. In Example 3 shown in FIG. 15, the same hysteresis was obtained in the plane, but in Example 1 shown in FIG. 14, a change in the coercive electric field of hysteresis measurement was obtained at the end of the 3-inch substrate SB.

  Therefore, the PZT film 42 is cut at each of the hysteresis measurement points at the center position and the end position (position 35 mm from the center; see FIG. 13) of the PZT film 42 to obtain a TEM-EDX (field emission type). With a transmission electron microscope (energy dispersive X-ray analyzer), the measurement diameter is set to a spot diameter of about 50 nm, as shown in FIG. 9, the measurement position 43a near the interface of the lower electrode 32 of the PZT film 42, and the PZT film 42 The Pb amount (= Pb / (Zr + Ti)) is measured at multiple points (samples) at any measurement position at the measurement position 43b near the center in the depth direction and the measurement position 43c near the interface of the upper electrode 44 of the PZT film 42. did. The measurement was performed at a measurement position 43a near the interface of the lower electrode 32 at a position not facing Ir.

In any sample (measurement point) at any measurement position, the lead amount was about 1 at the measurement position 43b near the center of the PZT film 42 and the measurement position 43c near the interface of the upper electrode 44 of the PZT film 42. (In the case of TEM-EDX, the measurement reproducibility is poor compared with XRF, and the lead amount between 0.95 and 1.05 is set to about 1.)
Further, in Example 3, the lead amount was about 1 even at the measurement position 43a near the lower electrode of the PZT42 film. However, in Examples 1 and 2, depending on the measurement location (measurement position and measurement point) of EDX. The lead amount measurement place of about 1 and the lead amount measurement place where the lead amount is 0.8 or less were found.
Here, Table 2 shows the number of measurement points for the lead amount of 0.8 or less at the center position and the end position (position 35 mm from the center; see FIG. 13) of the PZT film 42.
Moreover, in Example 1, the measurement result which measured 4 each (each sample number n = 4) for each measurement position 43a, 43b, and 43c is shown in FIG.

As is apparent from FIG. 16, in Example 1, at the central position of the PZT film 42 (see FIG. 13), at any of the measurement positions 43a, 43b, and 43c, the lead amount is about 1 at all four points (samples). It was found that there was no lead (Pb) deficiency.
On the other hand, at the position of the end of the PZT film 42 (position 35 mm from the center; see FIG. 13), at the measurement positions 43b and 43c, 4 points (samples) are about 1 lead amount, and lead (Pb) deficiency is However, at the measurement position 43a in the vicinity of the interface of the lower electrode 32 of the PZT film 42, it can be seen that lead (Pb) deficiency occurred at three points out of four points (samples).

Further, as shown in FIGS. 14 and 15, since it can be seen that there is a difference in the ferroelectric hysteresis measurement in Example 1 and Example 3, in order to compare both easily, the center position and the end position ( The magnitude of the polarization value was compared at an electric field of 50 kV / cm at a large change (position 35 mm from the center). As a result, the polarization value of Example 1 was estimated to be 3.2, and the polarization value of Example 3 was estimated to be 1.0. Moreover, the polarization value of Example 2 was estimated to be 2.9.
The results are shown in Table 2.

As can be seen from Table 2, in Examples 1 to 3, a perovskite single-phase film was obtained, but it can be seen that increasing the proportion of the conductive area can ensure uniformity in the vicinity of the lower electrode interface. That is, even in the same perovskite film, the electrical characteristics are different, and this is considered to be due to the difference in the amount of lead near the interface. It was found that the lead loss observed in the comparative example can be suppressed even at the initial stage of film formation at the edge of the substrate when the proportion of the conductive area is further expanded.
In addition, as can be seen from the comparison between Examples 1 and 2 and 3, the Inconel plate installed outside the film formation substrate is not effective at all if it is simply placed in a floating state. However, it was found that it was important to be electrically connected to the film formation substrate and to be equipotential with the film formation substrate.

(Experiment 3)
Example 4
In place of the 120 mm inconel plate 26 in Example 3, an inconel plate having a 100 mm (conducting ratio of 170%) was used to perform the same experiment as in experiment 2 to measure hysteresis.
The results are shown in Table 3.
As is apparent from Table 3, it was confirmed that in the case of Example 4 as well as Example 3, a uniform film was obtained at a conduction ratio of about 170%.
From the above experiments, it was found that in the film formation, it is essential to provide a conductive portion outside the film formation substrate, and the area ratio is more preferably 170% or more.

(Experiment 4)
In Examples 3 and 4, changes due to repeated film formation were examined.
The results are shown in Table 4.
As is apparent from Table 4, when the number of film formations is repeated, it is considered that the insulating film adheres to the equipotential surface, and the equipotential surface installed with great effort does not function as the equipotential surface.
In Example 3, a change was observed in the external electrical characteristics at the third film formation, but in Example 4, no change was observed in the entire film even after the film formation was repeated five times. Therefore, it was found that the area ratio of 250% is more preferable than the area ratio of 170%.
On the plate on which the film formation was repeated four times, an insulating film having a thickness of 16 μm, which is four times the film thickness of 4 μm, was deposited, and the fifth film formation was started. Therefore, it was found that the insulating film thickness when the proportion of the conductive area is 170% is preferably 10 μm or less.

(Experiment 5)
A similar experiment was conducted using a sputtering device manufactured by Shinko Seiki, changing the sputtering device. The composition of the film formation target material TG is the same, and as the film formation substrate SB, the same silicon substrate as used in Experiments 1 to 4 on which Ir and Ti have been formed is cut into 25 mm squares, and an Inconel composition of 30 mmφ is formed. A film was formed using a film jig. The conduction area ratio of this Inconel film forming jig was 13%.
(Example 5)
As a result of film formation under the above conditions and measurement of the obtained PZT film by XRD, it was a perovskite single phase film.
(Comparative Example 2)
On the other hand, as a result of forming an insulating film on the back surface of the Inconel jig used in Example 5 and insulating the film from the film formation substrate, the film became pyrochlore.
From the results of Example 5 and Comparative Example 2 of Experiment 5, it was found that the effect of the present invention can be obtained even when the conduction area ratio of the equipotential surface of the film-forming jig is 13%. Of course, it has been found that the effects of the present invention can be obtained regardless of the type of sputtering apparatus.

  The sputtering method and apparatus of the present invention can be applied to the case where a thin film such as a piezoelectric film, an insulating film, or a dielectric film is formed by a vapor phase growth method using plasma such as sputtering. The present invention can be applied to film formation of a ferroelectric film (FRAM), a piezoelectric film used for a pressure sensor, and the like.

It is a schematic sectional drawing which shows the apparatus structure of one Embodiment of the sputtering device which enforces the sputtering method of this invention. It is a flowchart which shows an example of the sputtering method of this invention. It is a schematic diagram which shows typically the mode during the film-forming in the sputtering device shown in FIG. It is explanatory drawing which shows the measuring method of the plasma potential Vs and the floating potential Vf in a sputtering device. It is a graph which shows a XRD measurement result about the various piezoelectric films formed by the method of the present invention with the film formation temperature Ts on the horizontal axis and the potential difference Vs−Vf on the vertical axis. It is sectional drawing which shows the structure of one Embodiment of the piezoelectric element of this invention, and an inkjet head using the same. It is a block diagram which shows the structure of one Embodiment of an inkjet type recording apparatus provided with the inkjet head shown in FIG. FIG. 8 is a partial top view of the ink jet recording apparatus shown in FIG. 7. It is typical sectional drawing which shows the structure and measurement position of the film-forming board | substrate used in the Example of this invention, and the thin film formed on the film-forming board | substrate. (A) And (b) is typical sectional drawing which shows typically the periphery structure and target material of the film-forming board | substrate in Example 1 and Comparative Example 1 of this invention, respectively. It is typical sectional drawing which shows typically the surrounding structure of the film-forming board | substrate in Example 2 of this invention, and a target material. It is typical sectional drawing which shows typically the peripheral structure of the film-forming board | substrate in Example 3 of this invention, and a target material. It is a conceptual diagram which shows the measurement position of the ferroelectric hysteresis measurement in each Example of this invention. It is a graph which shows the result of the dielectric hysteresis measurement in Example 1 of this invention. It is a graph which shows the result of the dielectric hysteresis measurement in Example 3 of this invention. It is a graph which shows the measurement result of the amount of lead in Example 1 of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Sputtering device 12 Vacuum vessel 12a Gas introduction pipe 12b Gas discharge pipe 14 Sputter electrode (cathode electrode)
16 High-frequency power supply 18 Substrate holder 18a Base 18b Substrate mount 18c Substrate holding member 18d L-shaped portion 18d
20 Equipotential surface forming member (equipotential plate)
20a Equipotential surface 20b Center opening 50, 50K, 50C, 50M, 50Y Inkjet head 52 Piezoelectric element 54 Ink reservoir / discharge member 56 Vibration plate 58 Substrate (support substrate)
60, 64 Electrode 62 Piezoelectric film 68 Ink chamber 70 Ink discharge port 100 Inkjet recording apparatus IP plus ion P Plasma space SB substrate (film formation substrate)
SBa Conductive surface TG Target material Tp Element of target material

Claims (23)

  A sputtering method for forming a thin film on a deposition substrate having a conductive surface on at least one surface, wherein the equipotential is equipotential with the conductive surface of the deposition substrate outside the deposition substrate. A sputtering method, wherein an equipotential surface forming member having a surface is installed, and the thin film is formed on the conductive surface of the deposition substrate.   The sputtering method according to claim 1, wherein an area of the equipotential surface of the equipotential surface forming member is 40% or more of an area of the conductive surface of the film formation substrate outside the film formation substrate.   The sputtering method according to claim 2, wherein an area of the equipotential surface of the equipotential surface forming member is 70% or more of an area of the conductive surface of the film formation substrate outside the film formation substrate.   The sputtering method according to claim 3, wherein an area of the equipotential surface of the equipotential surface forming member is 150% or more of an area of the conductive surface of the film formation substrate outside the film formation substrate.   The sputtering method according to claim 1, wherein the equipotential surface forming member is a member having a thickness of 10 μm or less of an insulating film attached to the equipotential surface.   The sputtering method according to claim 1, wherein the equipotential surface forming member is a member having no insulating film attached to the equipotential surface.   The said film | membrane is produced on the said electroconductive surface of the said film-forming board | substrate, while the thickness of the insulating film adhering to the said equipotential surface of the said equipotential surface formation member is 0 or 10 micrometers or less. 7. The sputtering method according to any one of 6 above.   The sputtering method according to claim 1, wherein a film forming material for forming the film is an insulator.   The sputtering method according to claim 1, wherein a film forming material for forming the film contains lead titanate or lead zirconate.   The sputtering method according to claim 1, wherein the deposition substrate is a conductive substrate.   The sputtering method according to claim 1, wherein the conductive surface of the film formation substrate and the equipotential surface of the equipotential surface forming member are electrically connected. A vacuum vessel;
A sputtering electrode provided in the vacuum vessel and holding a sputtering target material;
A high frequency power source connected to the sputter electrode and applying a high frequency to the sputter electrode;
A substrate holder in the vacuum vessel that is spaced apart from the sputter electrode and that holds a film-forming substrate having a conductive surface on at least one surface on which a thin film is formed by the component of the target material When,
An equipotential surface forming member installed outside the film formation substrate held by the substrate holder;
The equipotential surface forming member has an equipotential surface that is equipotential with the conductive surface of the film formation substrate on the side facing the sputter electrode, and the thin film has the conductivity of the film formation substrate. A sputtering apparatus produced on the surface of the substrate.   The sputtering apparatus according to claim 12, wherein the equipotential surface forming member has an area of the equipotential surface outside the deposition substrate that is 40% or more of an area of the conductive surface of the deposition substrate.   The sputtering apparatus according to claim 13, wherein the equipotential surface forming member has an area of the equipotential surface outside the deposition substrate that is 70% or more of an area of the conductive surface of the deposition substrate.   The sputtering apparatus according to claim 14, wherein the equipotential surface forming member has an area of the equipotential surface outside the film formation substrate that is 150% or more of an area of the conductive surface of the film formation substrate.   The sputtering apparatus according to claim 12, wherein the deposition substrate is a conductive substrate.   The sputtering apparatus according to claim 12, wherein the conductive surface of the film formation substrate and the equipotential surface of the equipotential surface forming member are electrically connected.   The sputtering apparatus according to claim 12, wherein the equipotential surface forming member is a member having an insulating film attached to the equipotential surface having a thickness of 10 μm or less.   The sputtering apparatus according to claim 12, wherein the equipotential surface forming member is a member having no insulating film attached to the equipotential surface.   The sputtering apparatus according to claim 12, wherein the equipotential surface forming member has a thickness of an insulating film attached to the equipotential surface of 0 or 10 μm or less.   21. The sputtering apparatus according to claim 12, wherein a film forming material for forming the film is an insulator.   The sputtering apparatus according to any one of claims 12 to 21, wherein a film forming material for forming the film contains lead titanate or lead zirconate.   The said equipotential surface formation member is installed so that the said equipotential surface may exist in the side near the said sputtering electrode rather than the said electroconductive surface of the said film-forming board | substrate. Sputtering equipment.

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