JP5849663B2 - Method for manufacturing vibration transducer - Google Patents

Description

  The present invention relates to a method for manufacturing a vibratory transducer.

FIGS. 6 to 18 are explanatory views of the main configuration of a conventional example that is generally used conventionally.
FIG. 6 is an explanatory diagram of an essential part assembly configuration, FIGS. 7 to 15 are explanatory diagrams of manufacturing processes, FIG. 16 is a circuit explanatory diagram of FIG. 6, and FIGS. 17 to 18 are operation explanatory diagrams of FIG.
This will be described according to the manufacturing process.
In FIG. 7, a silicon oxide film 10a is formed on the N-type silicon single crystal substrate 1 and patterned.
The portion from which the oxide film has been removed is undercut to form a recess, and P ⁺ single crystal silicon 11 is grown by selective epitaxial growth with P-type silicon having a boron concentration of 10 ¹⁸ cm ⁻³ .
Next, the P ⁺⁺ single crystal silicon 12 is grown on the surface of the P ⁺ single crystal silicon 11 by closing the recess with P-type silicon having a boron concentration of 3 × 10 ¹⁹ cm ⁻³ or more.
Later, the P ⁺ single crystal silicon layer becomes the gap under the vibrating beam, and the P ⁺⁺ single crystal silicon layer becomes the vibrating beam.

In FIG. 8, a silicon oxide film 10b is formed on the substrate surface including the P ⁺⁺ single crystal silicon 12 and patterned.
The portion indicated by the recess D from which the oxide film has been removed becomes a grounding portion of the shell to the substrate.
In FIG. 9, a silicon nitride film 13 is formed on the substrate surface including the recess D and patterned. The silicon oxide film 10b and the silicon nitride film 13 on the P ⁺⁺ single crystal silicon 12a (vibrating beam) form a gap on the vibrating beam. The capacitance is determined by the film thickness and the area of the vibrating beam. Therefore, by adjusting these values so as to obtain a desired capacitance, it is possible to optimize the capacitance for driving and detecting the vibrating beam.

In FIG. 10, P ⁺⁺ polysilicon 14 is formed on the entire surface, and an etching solution introduction hole E for sacrificial layer etching is formed by patterning.
This P ⁺⁺ polysilicon will later become a wiring for shell and electrode extraction.
The wiring can be formed by using P ⁺⁺ / P ⁺ single crystal silicon or by diffusing impurities into the silicon substrate before selective epitaxial growth.
It is preferable to select the parasitic capacitance between the wiring and the silicon substrate to be the smallest.

In FIG. 11, hydrofluoric acid is introduced from the etching solution introduction hole E to remove the silicon nitride film 14 and the silicon oxide film 12b.
Since the etching rate of the silicon nitride film 14 is slow at the ground portion of the shell to the substrate, the silicon nitride film serves as an etching stop layer in the lateral direction.

In FIG. 12, the P ⁺ single crystal silicon layer 11 is removed with an alkaline solution (hydrazine, KOH, TMAH, etc.).
At this time, the P ⁺⁺ single crystal silicon 12a and the P ⁺⁺ polysilicon 14 are not etched because impurities are introduced at a high concentration.
Further, by applying a voltage of 1 to 2 V to the N-type silicon substrate during etching with an alkaline solution, it can be protected from being etched.
The length direction of the vibrating beam is set as an etching stop by taking advantage of the slow etching rate of the silicon single crystal in the <111> direction.

In FIG. 13, a sealing member 15 (for example, SiO 2 or glass formed by sputtering) is formed by sputtering, vapor deposition, CVD, epitaxial growth, or the like to close the etching solution introduction hole, and a fine vacuum chamber 5 is formed. To do.
Prior to this step, it is possible to further stabilize the electrical insulation between the shell and the vibrating beam by a method such as forming a silicon oxide film on the surface of the vibrating beam and inside the vacuum chamber by thermal oxidation or the like.
In this case, a conductive material can be used as the sealing member.

In FIG. 14, P ⁺⁺ polysilicon 14 is patterned to form electrical wiring from the vibrating beam and shell, and to form an electrode for a bonding pad.
In FIG. 15, the silicon substrate is thinned from the back surface to form a diaphragm.
FIG. 16A is a plan view showing a state in which the P ⁺⁺ polysilicon 14 is patterned by connecting to the vibrating beam 12a and the shell 14 to form an electrical wiring 20 and an Al electrode 21 for bonding. .

FIG. 16B shows a circuit diagram of the vibration type transducer of the present invention.
In the figure, Vb is a bias voltage (constant voltage), Vi is a drive voltage (AC), R1 and R2 are wiring resistances, and R3 is a substrate resistance.
C1 is a capacitance between the vibrating beam / shell, C2 is a parasitic capacitance, and C3 and C4 are capacitances between the wiring and the substrate. In the figure, the smaller the R3, C2, 3 and 4, the smaller the noise current.
These values are determined by the wiring formation method, pattern, and the like. Therefore, these values are determined to be as small as possible.
In the figure, when the capacitance C1 between the vibrating beam and the shell is constant, assuming that the frequency of Vi is ω, the amplitude of the output current is proportional to (C1 + C2) · Vi · ω.
On the other hand, when C1 resonates at frequency ω, assuming that the change in C1 due to resonance is ΔC1, a current having an amplitude approximately proportional to ΔC1 · Vb · ω is added. The resonance frequency is detected from the increase in current.

By the way, if the initial tension is not applied to the vibrator 3 even when the measurement pressure Pm is zero, the measurement cannot be performed due to buckling due to the measurement pressure Pm, and variation in the initial tension is not controlled. As a result, variations in sensitivity occur.
This point will be described below.
FIG. 17 shows the relationship between the covalent bond radius Ri of various impurities and the covalent bond radius Ri of each impurity relative to the covalent bond radius RSi of silicon.
FIG. 18 shows the change of the lattice constant with respect to the impurity concentration.
As can be seen from FIG. 17, phosphorus (P) is as small as 1.10 Å and boron (B) is as small as 0.88 Å relative to the covalent bond radius Rsi1.17 シ リ コ ン of silicon (Si).
Therefore, when boron or phosphorus is implanted into silicon, this part is subjected to tensile strain. From FIG. 18, for example, the degree of this strain is about 2 × 10 ⁻³変 化 when the boron concentration is 10 ²⁰ cm ⁻³ , while the lattice constant of silicon is 5.431 約. 4 × 10 ⁻⁴ ε (= 2 × 10 −3 / 5.341).

In order to give a strain of 4 × 10 ⁻⁴ ε or more, for example, if boron is injected twice by 2 × 10 ²⁰ cm ^−3, an initial tension of 8 × 10 ⁻⁴ ε is generated in proportion to the injection amount. . Therefore, if an arbitrary concentration of boron is implanted, an arbitrary initial tension can be applied.
The vibrator 3 shown in FIG. 6 is given an initial tension using this.
In order to give a strain of less than 4 × 10 ⁻⁴ ε, the phosphorus concentration of the n-type silicon substrate 1 is increased, or the oscillator 3 is oxidized to remove boron on the surface of the oscillator in the oxide film. By removing the oxide film with BHF, the boron concentration in the vibrator 3 can be lowered and the strain can be adjusted to 4 × 10 ⁻⁴ ε or less.
Further, as can be seen from FIG. 17, it is estimated that almost no distortion occurs at a boron concentration of about 10 ¹⁷ cm ⁻³ .

JP-A-01-299428 Japanese Patent Laying-Open No. 2005-037309

Such an apparatus has the following problems.
In the conventional example, since the vibrating beam vibrates perpendicularly to the substrate and the vibrating beam, the excitation electrode, and the vibration detection electrode have a laminated structure, many processing steps are required in the manufacturing process.
In the conventional example, after the epitaxial growth, etching is stopped using the difference in boron concentration to form the vibrator. In this method, since the boron concentration must be higher than a certain level, the available boron concentration is limited. Due to this limitation, the tension of the vibrating beam cannot be sufficiently controlled. Further, the shape of the vibrating beam varies greatly because it is determined by the impurity concentration difference.
Further, in the normal epitaxial method, it is difficult to accurately control the vibrator tension due to the generation of defects and dislocations in the vibrator, and when the vibrator is thick, high tension cannot be generated. For this reason, it is not possible to form a thick vibrator having high tension by a normal epitaxial method. On the other hand, in a normal diffusion system, when a thick vibrator having tension is formed, it is necessary to extend the diffusion length, and thus long diffusion is required.
For example, high tension exceeding 300 ue could not be generated.
Further, when the vibrator is formed by an epitaxial method, if the film thickness is thick enough to exceed about 5 μm, the tension is lowered, so that a thick vibrator cannot be formed in the height direction.

  An object of the present invention is to solve the above-described problems, and to provide a vibratory transducer having a vibratory beam having high accuracy and high tension.

In order to achieve such a problem, in the present invention, in the manufacturing method of the vibratory transducer according to claim 1,
A vibrating beam provided on a silicon single crystal substrate, a shell made of a silicon material surrounding the vibrating beam so as to maintain a gap around the vibrating beam and forming a vacuum chamber together with the substrate, and the vibrating beam Manufacturing of a vibratory transducer comprising excitation means for exciting and vibration detecting means for detecting vibration of the vibrating beam , and measuring a strain applied to the vibrating beam by measuring a resonance frequency of the vibrating beam In the method
A silicon single crystal vibrating beam provided in the vacuum chamber and provided with a tensile stress to the substrate;
A plate-like first electrode plate provided in parallel to the substrate surface and having one end connected to the vibrating beam;
A plate-like second plate that is provided in parallel with the substrate surface across the vibrating beam and having a facing gap and that forms a flat surface parallel to the substrate surface together with the vibrating beam and the first electrode plate. A third electrode plate;
Comprising
A method of manufacturing a vibratory transducer, wherein a silicon single crystal vibrating beam provided in the vacuum chamber and applied with tensile stress to the substrate includes the following steps.
(1) An impurity-containing layer film forming step of forming at least one high impurity concentration layer and a low impurity concentration layer for applying tensile stress to the vibrating beam on the silicon layer on one surface of the SOI substrate.
(2) A facing gap forming step of forming the facing gap by etching in the silicon layer on one surface of the SOI substrate and the impurity-containing layer.
(3) A vibrating beam etching forming step of etching the silicon oxide of the SOI substrate to form the vibrating beam.

In the manufacturing method of the vibration type transducer according to claim 2 of the present invention,
A vibrating beam provided on a silicon single crystal substrate, a shell made of a silicon material surrounding the vibrating beam so as to maintain a gap around the vibrating beam and forming a vacuum chamber together with the substrate, and the vibrating beam Manufacturing of a vibratory transducer comprising excitation means for exciting and vibration detecting means for detecting vibration of the vibrating beam , and measuring a strain applied to the vibrating beam by measuring a resonance frequency of the vibrating beam In the method
A silicon single crystal vibrating beam provided in the vacuum chamber and provided with a tensile stress to the substrate;
A plate-like first electrode plate provided in parallel to the substrate surface and having one end connected to the vibrating beam;
A plate-like second plate that is provided in parallel with the substrate surface across the vibrating beam and having a facing gap and that forms a flat surface parallel to the substrate surface together with the vibrating beam and the first electrode plate. A third electrode plate;
Comprising
A method of manufacturing a vibratory transducer, wherein a silicon single crystal vibrating beam provided in the vacuum chamber and applied with tensile stress to the substrate includes the following steps.
(1) An impurity-containing layer film forming step of forming at least one high impurity concentration layer and a low impurity concentration layer that apply tensile stress to the vibrating beam on one surface of the silicon substrate.
(2) A facing gap forming step of forming the facing gap by etching on one surface of the impurity-containing layer and the silicon substrate or on the impurity-containing layer.
(3) A vibrating beam etching forming step of forming the vibrating beam by etching one surface of the silicon substrate.

The present invention has the following effects.
Even when the measurement pressure is not applied to the vibrating beam, if the tension is not applied, the measurement beam is applied, and the vibrating beam is buckled and cannot be measured. For this reason, tension is applied to the vibrating beam by adding boron or phosphorus having an atomic radius smaller than that of silicon atoms as impurities to the vibrating beam.
In the case of forming an impurity-containing film by an epitaxial method, if a single-layer thick film is formed, the tension of the vibrating beam is relaxed due to crystal defects and the like.
In the present invention, by introducing the low impurity concentration layer between the high impurity concentration layers forming the vibrating beam, the generation of crystal defects can be suppressed and the high tension of the vibrating beam can be maintained.
The tension value of the vibrating beam can be controlled by increasing the number of silicon layers introduced between the impurity-containing films, increasing the film thickness, or adjusting the impurity concentration of the impurity-containing film.
Various vibrating beam / opposite gap shape structures can be produced.

It is principal part structure explanatory drawing of the vibration type transducer to which the manufacturing method of this invention is applied. It is principal part manufacturing process explanatory drawing of one Example of this invention. It is principal part manufacturing process explanatory drawing of the other Example of this invention. It is principal part manufacturing process explanatory drawing of the other Example of this invention. It is principal part manufacturing process explanatory drawing of the other Example of this invention. It is principal part structure explanatory drawing of the prior art example generally used conventionally. FIG. 7 is an explanatory diagram of the manufacturing process of FIG. 6. FIG. 7 is an explanatory diagram of the manufacturing process of FIG. 6. FIG. 7 is an explanatory diagram of the manufacturing process of FIG. 6. FIG. 7 is an explanatory diagram of the manufacturing process of FIG. 6. FIG. 7 is an explanatory diagram of the manufacturing process of FIG. 6. FIG. 7 is an explanatory diagram of the manufacturing process of FIG. 6. FIG. 7 is an explanatory diagram of the manufacturing process of FIG. 6. FIG. 7 is an explanatory diagram of the manufacturing process of FIG. 6. FIG. 7 is an explanatory diagram of the manufacturing process of FIG. 6. FIG. 7 is a circuit explanatory diagram of FIG. 6. It is operation | movement explanatory drawing of FIG. It is operation | movement explanatory drawing of FIG.

Hereinafter, the present invention will be described in detail with reference to the drawings.
FIGS. 1A and 1B are, for example, main part configuration explanatory views of an example of a vibration type transducer to which the manufacturing method of the present invention is applied, where FIG. 1A is a main part plan view and FIG. 1B is a main part sectional view.
FIG. 1 is shown, for example, in Japanese Patent Application No. 2010-203032, “Vibration transducer and manufacturing method thereof” filed on September 10, 2010 by the applicant of the present application.

In FIG. 1, a vibrating beam 32 is provided in a vacuum chamber 33, and a tensile stress is applied to the substrate 31 (measurement diaphragm), so that the cross-sectional thickness in the direction perpendicular to the surface 311 of the substrate 31 is longer than the parallel direction. It consists of a silicon single crystal having a cross-sectional shape.
The first electrode plate 34 is provided in parallel to the surface 311 of the substrate 31 and has one end connected to the vibrating beam 32 to form a plate shape.
The second and third electrode plates 35, 36 are provided with opposed gaps 37, 38 facing the surface 311 of the substrate 31 in parallel with the vibrating beam 32 interposed therebetween, and the vibrating beam 32 and the first electrode plate 35, 36. Together with the electrode plate 34, it forms a single plane parallel to the surface 311 of the substrate 31 and forms a plate.
39 is a shell.

FIG. 2 is an explanatory view of a main part manufacturing process of one embodiment of the present invention.
As shown in FIG. 2A, an SOI substrate 101 is prepared.
FIG. 2B shows an impurity-containing layer forming step, in which a high-concentration impurity-containing layer 102 that applies tensile stress to the vibrating beam 32 is applied to the silicon layer on one surface of the SOI substrate 101 by, for example, an epitaxial method. One layer is formed by using.
FIG. 2C shows an opposing gap forming step in which opposing gaps 37 and 38 are formed in the silicon layer on one surface of the SOI substrate 101 and the high impurity concentration layer 102 by etching.
FIG. 2D shows a vibrating beam etching process in which silicon oxide on the SOI substrate 101 is etched to form the vibrating beam 32.

As a result,
Even when the measurement pressure is not applied, the vibrating beam 32 is not able to be measured by buckling the vibrating beam 32 by applying the measurement pressure unless tension is applied. Therefore, tension is applied to the vibrating beam 32 by adding boron or phosphorus having an atomic radius smaller than that of silicon atoms as impurities to the vibrating beam 32.
When an impurity-containing film is formed by an epitaxial method, if a single layer with a large film thickness is formed, the tension of the vibrating beam 32 is relaxed due to crystal defects or the like.
In the present invention, the high tension of the vibrating beam 32 can be maintained by introducing the low impurity concentration layer between the high impurity concentration layer 102 forming the vibrating beam 32.
The tension value of the vibrating beam 32 is controlled by increasing the number of silicon layers introduced between the high impurity concentration layer 102, increasing the film thickness, or adjusting the impurity concentration of the high impurity concentration layer 102. can do.
Various structures of the vibrating beam 32 and the opposing gaps 37 and 38 can be produced.

FIG. 3 is an explanatory view of the main part configuration of another embodiment of the present invention.
Although the vibrating beam 32 is formed of two layers in the embodiment of FIG. 2, this embodiment is an embodiment in which the number of layers of the vibrating beam 32 is increased.
As shown in FIG. 3A, an SOI substrate 101 is prepared.
FIG. 3B shows an impurity-containing layer forming step, in which a first impurity high-concentration containing layer 201 is formed on the silicon layer on one surface of the SOI substrate 101 by using, for example, an epitaxial method.
FIG. 3C shows an impurity-containing layer film forming step in which an impurity low-concentration content layer 202 is formed on the first impurity high-concentration content layer 201.
FIG. 3D shows an impurity-containing layer film forming step in which a second impurity high-concentration content layer 203 is formed on the low-impurity content layer 202.
FIG. 3E shows a first gap high concentration layer 201, a low impurity concentration layer 202, a second high impurity concentration layer 203, and a silicon layer on one surface of the SOI substrate 101 in the facing gap forming step. Then, opposing gaps 37 and 38 are formed by etching.
FIG. 3F shows a vibrating beam 32 formed by etching silicon oxide on the SOI substrate 101 in the vibrating beam etching forming step.

As a result,
Even when the measurement pressure is not applied to the vibrating beam 32, if the tension is not applied, the measurement beam is applied to the vibrating beam 32, and the vibrating beam 32 cannot be measured. Therefore, tension is applied to the vibrating beam 32 by adding boron or phosphorus having an atomic radius smaller than that of silicon atoms as impurities to the vibrating beam 32.
When an impurity-containing film is formed by an epitaxial method, if a single layer with a large film thickness is formed, the tension of the vibrating beam 32 is relaxed due to crystal defects or the like.
In the present invention, the high tension of the vibration beam 32 can be maintained by introducing the low impurity concentration layer 202 between the high impurity concentration layers 201 and 203 forming the vibration beam 32.
The tension value of the vibrating beam 32 can be controlled by increasing the number of silicon layers introduced between the impurity-containing films, increasing the film thickness, or adjusting the impurity concentration of the impurity-containing film.
Various structures of the vibrating beam 32 and the opposing gaps 37 and 38 can be produced.

FIG. 4 is an explanatory view of the main part configuration of another embodiment of the present invention.
2 and 3, the SOI wafer 101 is used as the substrate, but this is an embodiment using a substrate made of only a silicon layer.
As shown in FIG. 4A, a wafer made of the silicon layer 301 is prepared.
FIG. 4B shows an impurity-containing layer forming step, in which a high-concentration impurity-containing layer 302 that applies tensile stress to the vibrating beam 32 is formed on one surface of the silicon substrate 301 by using, for example, an epitaxial method. Form a film.
FIG. 4C shows an opposing gap forming step in which opposing gaps 37 and 38 are formed on one surface of the silicon substrate 301 and the high impurity concentration layer 302 by etching.
FIG. 4D shows a vibrating beam 32 formed by etching one surface of the silicon substrate 301 in the vibrating beam etching forming step.
Incidentally, as is shown in FIG. 4 (c _2), may be etched until the one surface of the silicon substrate 301, also as is shown in FIG. 4 (d _2), the vibrating beam 32, the silicon substrate 301 One side may be included.

As a result,
Even when the measurement pressure is not applied to the vibrating beam 32, if the tension is not applied, the measurement beam is applied to the vibrating beam 32, and the vibrating beam 32 cannot be measured. Therefore, tension is applied to the vibrating beam 32 by adding boron or phosphorus having an atomic radius smaller than that of silicon atoms as impurities to the vibrating beam 32.
When an impurity-containing film is formed by an epitaxial method, if a single layer with a large film thickness is formed, the tension of the vibrating beam 32 is relaxed due to crystal defects or the like.
In the present invention, the high tension of the vibrating beam 32 can be maintained by introducing the high impurity concentration layer that forms the vibrating beam 32.
The tension value of the vibrating beam 32 can be controlled by increasing the number of silicon layers introduced between the impurity-containing films, increasing the film thickness, or adjusting the impurity concentration of the impurity-containing film.
Various structures of the vibrating beam 32 and the opposing gaps 37 and 38 can be produced.

FIG. 5 is an explanatory view showing the configuration of the main part of another embodiment of the present invention.
In the embodiment shown in FIG. 4, the vibrating beam 32 is formed of one or two layers, but in this embodiment, the number of layers of the vibrating beam 32 is increased.
As shown in FIG. 5A, a wafer made of a silicon layer 401 is prepared.
FIG. 5B shows an impurity-containing layer forming step in which a first impurity high-concentration containing layer 402 that applies tensile stress to the vibrating beam 32 is applied to one surface of the silicon substrate 401 by, for example, an epitaxial method. One layer is formed by using.
FIG. 5C shows an impurity-containing layer film forming step in which an impurity low-concentration layer 403 is formed on the first impurity high-concentration layer 402.
FIG. 5D shows an impurity-containing layer film forming step, in which a second impurity high-concentration content layer 404 is formed on the low-impurity content layer 403.
FIG. 5E shows an opposing gap formation step in which opposing gaps 37 and 38 are formed in the first high impurity concentration layer 402, the low impurity concentration layer 403, and the second high impurity concentration layer 404 by etching. .
FIG. 5F shows a vibrating beam etching process in which one surface of the silicon substrate 401 is etched to form the vibrating beam 32.
As shown in FIG. 5 (e ₂ ), one surface of the silicon substrate 401 may be etched, and as shown in FIG. 5 (f ₂ ), the vibration beam 32 is formed on the silicon substrate 401. One side may be included.

As a result,
Even when the measurement pressure is not applied to the vibrating beam 32, if the tension is not applied, the measurement beam is applied to the vibrating beam 32, and the vibrating beam 32 cannot be measured. Therefore, tension is applied to the vibrating beam 32 by adding boron or phosphorus having an atomic radius smaller than that of silicon atoms as impurities to the vibrating beam 32.
When an impurity-containing film is formed by an epitaxial method, if a single layer with a large film thickness is formed, the tension of the vibrating beam 32 is relaxed due to crystal defects or the like.
In the present invention, the high tension of the vibrating beam 32 can be maintained by introducing the low impurity concentration layer 403 between the high impurity concentration layers 402 and 404 forming the vibrating beam 32.
The tension value of the vibrating beam 32 can be controlled by increasing the number of silicon layers introduced between the impurity-containing films, increasing the film thickness, or adjusting the impurity concentration of the impurity-containing film.
Various structures of the vibrating beam 32 and the opposing gaps 37 and 38 can be produced.

The above description merely shows a specific preferred embodiment for the purpose of explanation and illustration of the present invention.
Therefore, the present invention is not limited to the above-described embodiments, and includes many changes and modifications without departing from the essence thereof.

1 Silicon Substrate 2 Measurement Diaphragm 3 Vibrating Beam 4 Shell 5 Vacuum Chamber 31 Substrate (Measurement Diaphragm)
311 Surface of substrate 31 Vibrating beam 33 Vacuum chamber 34 First electrode plate 35 Second electrode plate 36 Third electrode plate 37 Opposing gap 38 Opposing gap 39 Shell 101 SOI substrate 102 High impurity content layer 201 First High impurity concentration layer 202 Low impurity concentration layer 203 Second high impurity concentration layer 301 Silicon substrate 302 High impurity concentration layer 401 Silicon substrate 402 High impurity concentration layer 403 Low impurity concentration layer 404 Second High impurity content layer

Claims (2)

A vibrating beam provided on a silicon single crystal substrate, a shell made of a silicon material surrounding the vibrating beam so as to maintain a gap around the vibrating beam and forming a vacuum chamber together with the substrate, and the vibrating beam Manufacturing of a vibratory transducer comprising excitation means for exciting and vibration detecting means for detecting vibration of the vibrating beam , and measuring a strain applied to the vibrating beam by measuring a resonance frequency of the vibrating beam In the method
A silicon single crystal vibrating beam provided in the vacuum chamber and provided with a tensile stress to the substrate;
A plate-like first electrode plate provided in parallel to the substrate surface and having one end connected to the vibrating beam;
A plate-like second plate that is provided in parallel with the substrate surface across the vibrating beam and having a facing gap and that forms a flat surface parallel to the substrate surface together with the vibrating beam and the first electrode plate. A third electrode plate;
Comprising
A method of manufacturing a vibratory transducer, wherein a silicon single crystal vibrating beam provided in the vacuum chamber and applied with tensile stress to the substrate includes the following steps.
(1) An impurity-containing layer film forming step of forming at least one high impurity concentration layer and a low impurity concentration layer for applying tensile stress to the vibrating beam on the silicon layer on one surface of the SOI substrate.
(2) A facing gap forming step of forming the facing gap by etching in the silicon layer on one surface of the SOI substrate and the impurity-containing layer.
(3) A vibrating beam etching forming step of etching the silicon oxide of the SOI substrate to form the vibrating beam. A vibrating beam provided on a silicon single crystal substrate, a shell made of a silicon material surrounding the vibrating beam so as to maintain a gap around the vibrating beam and forming a vacuum chamber together with the substrate, and the vibrating beam Manufacturing of a vibratory transducer comprising excitation means for exciting and vibration detecting means for detecting vibration of the vibrating beam , and measuring a strain applied to the vibrating beam by measuring a resonance frequency of the vibrating beam In the method
A silicon single crystal vibrating beam provided in the vacuum chamber and provided with a tensile stress to the substrate;
A plate-like first electrode plate provided in parallel to the substrate surface and having one end connected to the vibrating beam;
A plate-like second plate that is provided in parallel with the substrate surface across the vibrating beam and having a facing gap and that forms a flat surface parallel to the substrate surface together with the vibrating beam and the first electrode plate. A third electrode plate;
Comprising
A method of manufacturing a vibratory transducer, wherein a silicon single crystal vibrating beam provided in the vacuum chamber and applied with tensile stress to the substrate includes the following steps.
(1) An impurity-containing layer film forming step of forming at least one high impurity concentration layer and a low impurity concentration layer that apply tensile stress to the vibrating beam on one surface of the silicon substrate.
(2) A facing gap forming step of forming the facing gap by etching on one surface of the impurity-containing layer and the silicon substrate or on the impurity-containing layer.
(3) A vibrating beam etching forming step of forming the vibrating beam by etching one surface of the silicon substrate.