JP2015213208A - Manufacturing method of functional device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a functional element capable of suppressing a defect such as a defective shape in the functional element.SOLUTION: A manufacturing method of a functional element includes: a seed layer formation step of forming a seed layer 20 on a substrate 10; a mask layer formation step of forming a mask layer 40 having opening portions 41 on the seed layer 20; an oxide film formation step of forming oxide films 50 obtained by applying oxidation treatment of the mask layer 40 with a film thickness of surface roughness of the mask layer 40 within a range of Ra to 100 nm at least at a part of an exposed surface of the mask layer 40; a seed layer etching step of performing etching of the seed layer 20 subsequent to formation of the oxide film 50; and a substrate etching step of performing etching of the substrate 10 subsequent to the etching of the seed layer 20.

Description

  The present invention relates to a method for manufacturing a functional element.

Conventionally, as an example of a method for manufacturing an object including functional elements using etching, an opening is provided on an etching target layer including at least one of silicon carbide, silicon oxide, and the like, and nickel chrome is formed from the etching target layer side. 2. Description of the Related Art A method for manufacturing a semiconductor device is known which includes a step of forming a mask layer formed in the order of a film, a gold film, and a nickel film, and a step of etching a layer to be etched using the mask layer as a mask (for example, , See Patent Document 1).
The above-described method for manufacturing a semiconductor device has a high etching selectivity, which is a ratio of an etching rate of an etching target layer to a mask layer, and can suppress peeling of the mask layer from the etching target layer. .

JP 2007-234912 A

However, in the above manufacturing method, as a pre-process for etching the etching target layer, a nickel chromium film in contact with the etching target layer of the mask layer and a gold film on the nickel chromium film (also referred to as a seed layer) are formed on the gold film. A process for removing the nickel film in accordance with the shape of the opening of the formed nickel film is required.
In the manufacturing method described above, since this step is performed by etching, not only the nickel chrome film and the gold film (seed layer) but also the nickel film, which is the main part of the mask layer, may be etched away.
As a result, in the above manufacturing method, the shape of the mask layer that determines the etching shape of the etching target layer (for example, the shape of the opening) changes from the original shape. There is a risk of problems such as defective shape.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A method of manufacturing a functional element according to this application example includes a step of forming a seed layer on a substrate, a step of forming a mask layer having an opening on the seed layer, and exposing the mask layer. Forming an oxide film obtained by oxidizing the mask layer on at least a part of the surface with a film thickness in the range of surface roughness Ra to 100 nm of the mask layer; and forming the oxide film, and then forming the seed layer Etching, and etching the seed layer and then etching the substrate.

According to this, in the method of manufacturing a functional element, a seed layer is formed on a substrate, a mask layer having an opening is formed on the seed layer, and the mask layer is oxidized on at least a part of the exposed surface of the mask layer. The processed oxide film is formed with a surface roughness Ra to 100 nm (0.1 μm) of the mask layer, and after forming the oxide film, the seed layer is etched, the seed layer is etched, and then the substrate (covered) is formed. (Corresponding to the etching layer) is etched.
Thereby, the manufacturing method of the functional element protects the mask layer by the physical properties of the oxide film and improves the etching resistance of the mask layer, thereby suppressing the change in shape of the mask layer due to the etching of the seed layer. Can do.
As a result, the method for manufacturing a functional element etches the substrate using the mask layer in which the change in shape is suppressed, so that it is possible to suppress defects such as shape defects in the functional element formed from the substrate.

If the thickness of the oxide film is less than the surface roughness Ra of the mask layer, film formation defects such as pinholes may occur. If the film thickness exceeds 100 nm, the film thickness varies greatly during film formation. As a result, the mask shape accuracy of the opening and the like deteriorates, so that there is a risk of deteriorating the shape defect rate of the substrate after etching.
For this reason, in the method for manufacturing the functional element, the thickness of the oxide film is set in the range of the surface roughness Ra to 100 nm of the mask layer.

  Application Example 2 In the method for manufacturing a functional element according to the application example, it is preferable that the oxide film is formed by a heat treatment in the atmosphere.

According to this, since the oxide film is formed by the heat treatment in the atmosphere in the method for manufacturing the functional element, the mask layer is etched by increasing the crystal grain size of the mask layer and narrowing the crystal grain boundary, for example. Resistance can be improved.
Moreover, the manufacturing method of a functional element can relieve the internal stress of a mask layer, for example by the annealing effect by slow cooling after a heating.
Moreover, since the manufacturing method of a functional element can be oxidized in the atmosphere, for example, the equipment required for the oxidation can be simplified compared to other methods in which the oxidation is performed in a vacuum.

  Application Example 3 In the method for manufacturing a functional element according to the application example, it is preferable that the oxide film is formed by oxygen plasma treatment.

According to this, since the oxide film is formed by the oxygen plasma treatment in the method for manufacturing the functional element, the oxide film is formed on the clean surface from which the foreign matter on the mask layer has been removed by the cleaning action of the oxygen plasma treatment. be able to.
As a result, the functional element manufacturing method can reliably protect the mask layer by the oxide film formed on the clean surface.

  Application Example 4 In the method for manufacturing a functional element according to the application example, it is preferable that the seed layer has a stacked structure in which a plurality of metals are stacked, and the uppermost layer of the seed layer is a gold layer.

According to this, since the seed layer has a laminated structure in which a plurality of metals are stacked and the uppermost layer of the seed layer is a gold layer, the functional element manufacturing method includes the step of forming an oxide film on the mask layer. The seed layer is hardly oxidized due to the physical properties of gold.
As a result, the method for manufacturing the functional element can easily etch the seed layer as compared with the case where the etching resistance is improved by oxidizing the seed layer.

  Application Example 5 In the method for manufacturing a functional element according to the application example, it is preferable that the mask layer contains nickel.

  According to this, since the mask layer contains nickel in the method for manufacturing a functional element, the etching resistance (particularly dry etching resistance) of the mask layer can be improved by the physical properties of nickel.

  Application Example 6 In the functional element manufacturing method according to the application example, it is preferable that the substrate is etched by dry etching.

According to this, since the method of manufacturing the functional element performs the etching of the substrate by dry etching, the side surface after etching is substantially perpendicular to the upper and lower surfaces (front and back surfaces) of the substrate due to the characteristics of dry etching. Can be etched.
As a result, the manufacturing method of the functional element can improve the shape accuracy of the functional element formed from the substrate.

  Application Example 7 In the method for manufacturing a functional element according to the application example, it is preferable that the substrate is a vibration plate and the functional element is a vibration element.

  According to this, since the substrate is a vibration plate and the functional element is a vibration element, the functional element manufacturing method can manufacture and provide a vibration element having high shape accuracy and excellent vibration characteristics.

The flowchart which shows the main manufacturing processes of the manufacturing method of a functional element. (A)-(d) is a schematic cross section explaining each manufacturing process of a front | former stage. (E)-(h) is a schematic cross section explaining each manufacturing process of a back | latter stage. It is a model perspective view explaining the H-type crystal vibrating piece which is an example of the vibration element as a functional element, (a) shows a drive vibration state, (b) shows a detection vibration state. 4A and 4B are schematic cross-sectional views taken along lines AA and BB in FIG. 4A, in which FIG. 4A shows a cross-sectional shape formed by dry etching, and FIG. 4B shows a cross-sectional shape formed by wet etching. Indicates.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Embodiments of the invention are described below with reference to the drawings.

(Embodiment)
FIG. 1 is a flowchart showing main manufacturing steps of a method for manufacturing a functional element. FIG. 2A to FIG. 2D and FIG. 3E to FIG. 3H are schematic cross-sectional views illustrating each manufacturing process. FIG. 4 is a schematic perspective view for explaining an H-type quartz crystal resonator element which is an example of a vibration element as a functional element. FIG. 4A shows a driving vibration state, and FIG. Indicates the vibration state.
In addition, in order to make it intelligible, the dimension ratio of each component differs from actual.

  As shown in FIG. 1, the functional element manufacturing method includes a substrate preparation step, a seed layer formation step, a mask layer formation step, an oxide film formation step, a seed layer etching step, a substrate etching step, and a peeling step. And.

[Board preparation process]
First, as shown in FIG. 2A, a substrate 10 is prepared. Here, as an example of a vibration plate as a substrate, a wafer-like quartz plate cut out at a predetermined angle from a quartz crystal or the like is prepared. Here, as an example, a quartz plate polished to a thickness of about 100 μm was prepared.
In addition to quartz, lithium tantalate (LiTaO ₃ ), lithium tetraborate (Li ₂ B ₄ O ₇ ), lithium niobate (LiNbO ₃ ), lead zirconate titanate (PZT) , Piezoelectric materials such as zinc oxide (ZnO) and aluminum nitride (AlN), and semiconductors such as silicon (Si).
In addition to the diaphragm, examples of the substrate include a semiconductor substrate such as silicon and a glass substrate.

[Seed layer formation process]
Next, as shown in FIG. 2B, a seed layer 20 is formed on the upper surface 11 of the substrate 10 by using, for example, a sputtering method or a vapor deposition method. The seed layer 20 is a base layer that becomes a seed for forming a mask layer described later.
Here, as an example, a chromium layer or a titanium layer having a thickness of about 50 nm is formed as the lower layer 21 of the seed layer 20, and a gold layer having a thickness of about 50 nm is formed thereon as the uppermost layer 22.
Thereby, the seed layer 20 has a laminated structure with a thickness of about 100 nm in which a plurality of metals (here, chromium or titanium and gold) are laminated.

[Mask layer forming step]
Next, as shown in FIG. 2C, a resist 30 is applied on the seed layer 20 by using, for example, a spin coating method, and the planar shape of a mask layer 40 to be described later using a photolithography method after curing. Then, the unnecessary resist 30 is removed leaving a region to be the opening 41 of the mask layer 40 (in other words, a region to be etched where the mask layer 40 is not formed).
Next, the mask layer 40 is formed in the region where the unnecessary resist 30 on the seed layer 20 is removed by using, for example, a plating method such as a semi-additive method.
Examples of the material of the mask layer 40 include nickel and copper. Here, the mask layer 40 having a thickness of about 10 μm is formed using nickel.
Next, as shown in FIG. 2D, the resist 30 in the opening 41 is removed using a release agent or the like to complete the mask layer 40.

[Oxide film formation process]
Next, as shown in FIG. 3E, an oxide film 50 obtained by oxidizing the mask layer 40 is applied to at least a part (here, all) of the exposed surface of the mask layer 40 with a surface roughness Ra˜ The film thickness is in the range of 100 nm (0.1 μm).
The method for forming the oxide film 50 is not particularly limited, and examples thereof include a method of forming by heat treatment in the atmosphere and a method of forming by oxygen plasma processing.

  As a method for forming the oxide film 50 by heat treatment in the atmosphere, for example, the substrate 10 that has been subjected to the mask layer formation step is put into a heating apparatus such as a heating furnace, a thermostatic bath, and a dryer, and about 200 ° C. to 300 ° C. The oxide film 50 is formed by heating in the temperature range for about 1 hour to several hours. The film thickness of the oxide film 50 can be appropriately set by adjusting the heating temperature, the heating time, and the like.

The method of forming the oxide film 50 by oxygen plasma treatment is, for example, that the substrate 10 that has been subjected to the mask layer formation step is placed in a vacuum chamber having a degree of vacuum of about 10 ⁻¹ Pa and oxygen plasma treatment is performed in an oxygen gas atmosphere. The oxide film 50 is formed by performing for about 10 minutes to several tens of minutes. The film thickness of the oxide film 50 can be appropriately set by adjusting the processing time, the degree of vacuum, the oxygen gas concentration, the high frequency output, the stage temperature on which the substrate 10 is placed, and the like.
By using these forming methods, the oxide film 50 is formed on the exposed surface including the corners of the mask layer 40 with a substantially uniform film thickness.

  For measuring the thickness of the oxide film 50, for example, an electron microscope (SEM), an XPS analysis method (also known as ESCA), or the like is used. The XPS analysis method is a method for calculating the thickness by measuring the energy distribution of photoelectrons emitted from a sample by X-ray irradiation, obtaining information on element identification and its chemical bonding state.

[Seed layer etching process]
Next, as shown in FIG. 3F, after the oxide film 50 is formed, a portion of the seed layer 20 exposed to the opening 41 of the mask layer 40 is etched.
For the etching of the gold layer that is the uppermost layer 22 of the seed layer 20, for example, an etching solution such as potassium iodide or aqua regia (a liquid in which concentrated hydrochloric acid and concentrated nitric acid are mixed at a volume ratio of 3: 1) is used.
After the etching of the gold layer of the uppermost layer 22, when the lower layer 21 of the seed layer 20 is a chromium layer, for example, etching is performed using an etching solution such as cerium nitrate. Etching is performed using an etching solution such as water.

[Substrate etching process]
Next, as shown in FIG. 3G, after the seed layer 20 is etched, a portion of the substrate 10 exposed to the opening 41 of the mask layer 40 is etched.
As the etching, either wet etching or dry etching may be used. Here, as an example, the substrate 10 is etched using dry etching.
In the dry etching, for example, the substrate 10 is etched using a reactive gas such as carbon tetrafluoride (CF ₄ ) gas. Here, a reactive ion etching method in which carbon tetrafluoride (CF ₄ ) gas is ionized and radicalized by plasma to perform etching is used.

In such dry etching, etching proceeds in a substantially perpendicular direction (substantially perpendicular direction) to the upper surface 11 of the substrate 10 with a corner 51 of the oxide film 50 covering the mask layer 40 as a boundary.
Therefore, the mask layer 40 is formed so as to be inclined so that the front end of the upper surface protrudes toward the opening 41 (in other words, the cross section is formed in an inverted trapezoidal shape). This is preferable for improving the shape accuracy of the substrate 10 (not shown).
In addition to the above, reactive gases for dry etching include gases such as sulfur hexafluoride (SF ₆ ) and trifluoromethane (CHF ₃ ).

[Peeling process]
Next, as shown in FIG. 3H, the mask layer 40 and the seed layer 20 are peeled off.
For removing the mask layer 40, for example, nitric acid is used, and for removing the seed layer 20, for example, the above-described potassium iodide, aqua regia, cerium nitrate, hydrogen peroxide solution, or the like is used.

  Through the above-described steps and the like, for example, an H-type crystal vibrating piece 1 as an example of a vibrating element as a functional element as shown in FIG. 4 can be obtained.

Here, an outline of the crystal vibrating piece 1 will be described. Note that the X, Y, and Z axes in FIG. 4 are coordinate axes that are orthogonal to each other.
As shown in FIG. 4, the quartz crystal resonator element 1 includes a substantially rectangular base 2, a pair of drive vibrating arms 3 a and 3 b extending from the + Y side end of the base 2 to the + Y side along the Y axis, A pair of vibrating arms for detection 4a and 4b extending from the end portion on the -Y side of the base portion 2 to the -Y side along the Y axis, and function as a vibrating gyro element.

As shown in FIG. 4A, the crystal resonator element 1 is configured such that when the drive signal is applied to drive electrodes (not shown) provided on the drive vibration arms 3a and 3b, the drive vibration arms 3a and 3b are Drive vibration is generated that bends and vibrates alternately in the direction approaching each other along the X axis (white arrow) and in the direction away from each other (black arrow).
As shown in FIG. 4B, when the crystal vibrating piece 1 is applied with an angular velocity ω around the Y axis in this drive vibration state, the drive vibration arms 3a and 3b and the detection vibration arms 4a and 4b However, the detection vibration that alternately bends in the + Z direction and the −Z direction along the Z axis is performed.

More specifically, when the driving vibrating arm 3a and the detecting vibrating arm 4b are bent in the + Z direction, the driving vibrating arm 3b and the detecting vibrating arm 4a are bent in the -Z direction (white arrow), and the driving vibrating arm 3a. When the detection vibrating arm 4b is bent in the −Z direction, the drive vibrating arm 3b and the detection vibrating arm 4a are bent in the + Z direction (black arrow) to perform detection vibration.
The quartz crystal vibrating piece 1 can derive the angular velocity ω by taking out the electric charges generated in the detection electrodes (not shown) provided in the detection vibrating arms 4a and 4b as a result of this detection vibration.

As described above, in the method of manufacturing the functional element according to the present embodiment, the seed layer 20 is formed on the substrate 10, the mask layer 40 having the opening 41 is formed on the seed layer 20, and the exposed surface of the mask layer 40. An oxide film 50 obtained by oxidizing the mask layer 40 is formed at least in part (here, all) with a film thickness in the range of the surface roughness Ra to 100 nm of the mask layer 40.
Then, after forming the oxide film 50, the seed layer 20 is etched, and after etching the seed layer 20, the substrate 10 is etched.

Thereby, in the method of manufacturing the functional element, the mask layer 40 is protected by the physical properties of the oxide film 50 and the etching resistance of the mask layer 40 is improved. Therefore, the shape of the mask layer 40 resulting from the etching of the seed layer 20 is improved. Change can be suppressed.
As a result, the method for manufacturing the functional element etches the substrate 10 using the mask layer 40 in which the change in shape is suppressed, so that the shape defect in the functional element (here, the crystal vibrating piece 1) formed from the substrate 10 and the like. Can be prevented.
Specifically, for example, the dimensional accuracy such as the arm width and arm length of the driving vibrating arms 3a and 3b and the detecting vibrating arms 4a and 4b of the crystal vibrating piece 1 can be improved, and the defect rate can be reduced. .

If the thickness of the oxide film 50 is less than the surface roughness Ra of the mask layer 40, film formation defects such as pinholes may occur. If the film thickness exceeds 100 nm, the film thickness varies during film formation. Since the mask shape accuracy of the opening 41 and the like deteriorates, the shape defect rate of the substrate 10 (crystal resonator element 1) after etching may be deteriorated.
For this reason, in the method for manufacturing the functional element, the thickness of the oxide film 50 is set in the range of the surface roughness Ra to 100 nm of the mask layer 40.

In the method of manufacturing the functional element, the oxide film 50 is formed by heat treatment in the atmosphere. For example, the crystal grain size of nickel or the like constituting the mask layer 40 increases, and the crystal grain boundary narrows. Further, the etching resistance (particularly dry etching resistance) of the mask layer 40 can be further improved.
Specifically, it has been confirmed that the nickel-etching rate is reduced by 0.1 μm / min in a heat-treated product that is heat-treated at 300 ° C. for 1 hour as compared with a room-temperature-treated product. If this is replaced with the etching selectivity (crystal etching amount / nickel etching amount), it is improved by about 1.0.

Moreover, the manufacturing method of a functional element can relieve | moderate the internal stress of the mask layer 40 by the annealing effect by slow cooling after heating, such as standing at normal temperature, for example.
As a result, the manufacturing method of the functional element can further improve the etching resistance of the mask layer 40 because the distortion of the mask layer 40 is reduced.
Moreover, since the manufacturing method of a functional element can be oxidized in the atmosphere, for example, the equipment required for the oxidation can be simplified compared to other methods in which the oxidation is performed in a vacuum.

Further, in the method of manufacturing the functional element, since the oxide film 50 is formed by oxygen plasma treatment, foreign substances (for example, organic substances) on the mask layer 40 are combined with, for example, oxygen ions or oxygen radicals to mask layer 40. The oxide film 50 can be formed on a clean surface that has been removed by the cleaning action of the oxygen plasma treatment, such as separation from the oxide film.
As a result, the method for manufacturing a functional element can reliably protect the mask layer 40 with the oxide film 50 formed on a clean surface.

Further, in the method of manufacturing the functional element, the seed layer 20 has a stacked structure in which a plurality of metals are stacked, and the uppermost layer 22 of the seed layer 20 is a gold layer. Therefore, the oxide film 50 is formed on the mask layer 40. In the oxide film forming step, the seed layer 20 is hardly oxidized due to the physical properties of gold.
As a result, the method for manufacturing the functional element can easily etch the seed layer 20 as compared with the case where the etching resistance is improved by oxidizing the seed layer 20.
Even if the uppermost layer 22 of the seed layer 20 is a palladium layer instead of the gold layer, the same effect can be obtained. Further, the seed layer 20 may have a single layer structure including only the lower layer 21 or the uppermost layer 22 or may have a stacked structure of three or more layers.

Moreover, since the mask layer 40 contains nickel, the manufacturing method of a functional element can improve the etching tolerance (especially dry etching tolerance) of the mask layer 40 with the physical property of nickel.
As a result, the method for manufacturing the functional element etches the substrate 10 using the mask layer 40 in which the shape change is further suppressed, so that the shape defect in the functional element formed from the substrate 10 (here, the quartz crystal resonator element 1). It is possible to further suppress problems such as.

In the method of manufacturing the functional element, since the substrate 10 is etched by dry etching, the etched side surface may be etched so as to be substantially perpendicular to the upper surface 11 of the substrate 10 depending on the characteristics of dry etching. it can.
As a result, the manufacturing method of the functional element can improve the shape accuracy in the crystal vibrating piece 1 which is an example of the vibrating element as the functional element formed from the substrate 10.

This point will be described in detail.
5A and 5B are schematic cross-sectional views taken along lines AA and BB in FIG. 4A. FIG. 5A shows a cross-sectional shape formed by dry etching, and FIG. Indicates a cross-sectional shape formed by wet etching. For convenience of explanation, the cross-sectional shapes of the driving vibrating arm and the detecting vibrating arm are the same (actually different). Note that FIG. 3H described above is a schematic cross-sectional view corresponding to FIG.
As shown in FIG. 5A, the cross-sectional shapes of the driving vibrating arms 3a and 3b and the detecting vibrating arms 4a and 4b of the quartz crystal vibrating piece 1 formed by dry etching are substantially the same on both sides with respect to the upper surface 11. It has a quadrangular shape formed at a right angle.
Thereby, the crystal vibrating piece 1 is a vibration component along directions other than the X-axis and the Z-axis of the driving vibrating arms 3a and 3b and the detecting vibrating arms 4a and 4b during driving vibration and detection vibration. Unnecessary vibration components can be suppressed.

On the other hand, as shown in FIG. 5B, the cross-sectional shapes of the driving vibrating arms 3a and 3b and the detecting vibrating arms 4a and 4b of the crystal vibrating piece 1 formed by wet etching are anisotropic to the crystal crystal etching. Depending on the nature, the side surface on the + X side has a complicated shape that is refracted so that the central portion protrudes to the + X side.
As a result, the quartz crystal resonator element 1 may include unnecessary vibration components in the vibration components of the drive vibration arms 3a and 3b and the detection vibration arms 4a and 4b during the drive vibration and the detection vibration.
As described above, when the crystal vibrating piece 1 is used as a vibrating gyro element, it is preferable to form it by dry etching in terms of vibration characteristics.
Note that unnecessary vibration components resulting from wet etching can be suppressed to an extent that there is no problem in actual use.

In addition, since the substrate 10 is a vibration plate and the functional element is a vibrating element (here, the quartz vibrating piece 1), the functional element manufacturing method is a vibrating element (quartz vibrating piece having high shape accuracy and excellent vibration characteristics. 1) can be manufactured and provided.
Note that the functional element is not limited to the vibration element, and includes a semiconductor element using a semiconductor substrate, a MEMS element using a glass substrate, a semiconductor substrate, and the like.

  DESCRIPTION OF SYMBOLS 1 ... Crystal vibrating piece which is an example of a vibration element as a functional element, 2 ... Base part, 3a, 3b ... Drive vibration arm, 4a, 4b ... Detection vibration arm, 10 ... Substrate, 11 ... Upper surface, 20 ... Seed layer 21 ... lower layer, 22 ... uppermost layer, 30 ... resist, 40 ... mask layer, 41 ... opening, 50 ... oxide film, 51 ... corner.

Claims (7)

Forming a seed layer on the substrate;
Forming a mask layer having an opening on the seed layer;
Forming an oxide film obtained by oxidizing the mask layer on at least a part of the exposed surface of the mask layer with a film thickness in the range of surface roughness Ra to 100 nm of the mask layer;
Etching the seed layer after forming the oxide film;
Etching the substrate after etching the seed layer;
The manufacturing method of the functional element characterized by including these. In the manufacturing method of the functional element according to claim 1,
A method of manufacturing a functional element, wherein the oxide film is formed by a heat treatment in the atmosphere. In the manufacturing method of the functional element according to claim 1,
A method of manufacturing a functional element, wherein the oxide film is formed by oxygen plasma treatment. In the manufacturing method of the functional element according to any one of claims 1 to 3,
The seed layer has a stacked structure in which a plurality of metals are stacked, and the uppermost layer of the seed layer is a gold layer. In the manufacturing method of the functional element as described in any one of Claims 1 thru | or 4,
The method for manufacturing a functional element, wherein the mask layer contains nickel. In the manufacturing method of the functional element as described in any one of Claims 1 thru | or 5,
A method of manufacturing a functional element, wherein the substrate is etched by dry etching. In the manufacturing method of the functional element as described in any one of Claims 1 thru | or 6,
The substrate is a vibration plate, and the functional element is a vibration element.

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