JPH10267659A - Angular velocity sensor and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an angular velocity sensor which can be manufactured through a simple process and has a small size and high output sensitivity. SOLUTION: An angular velocity sensor is constituted of a vibrator 2 which is partially supported on and fixed to a silicon substrate through an insulating film and has a vibratile beam-like shape, first and second electrodes 4 and 5 which respectively have side faces arranged in parallel to both side faces of the beam section of the vibrator 2 and at least parts of which are supported on and fixed to the silicon substrate through the insulating film, a driving means which vibrates the vibrator 2 in the direction perpendicular to the side faces of the vibrator 2, and a detecting means which detects the Coriolis force generated when the vibrator 2 rotates by using the surface of the silicon substrate facing the beam section of the vibrator 2 as a third electrode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an angular velocity sensor mounted on an automobile or the like for detecting a rotational angular velocity, and a method of manufacturing the same.

[0002]

2. Description of the Related Art FIGS. 9 and 10 show, for example, JP-A-5-322579.
FIG. 9 is a perspective view of a main part showing a schematic configuration, and FIG. 10 is a cross-sectional view. 9 and 10, reference numeral 1 denotes a first substrate made of an insulating material, 2 denotes a vibrator having a beam shape capable of supporting and fixing a part on the first substrate 1, and 3 denotes a first substrate 1. First detection electrodes 4 and 5 formed in the upper concave portion and facing the lower surface of the vibrator 2 in the direction of the Coriolis force are arranged so as to face both side surfaces of the beam portion of the vibrator 2 in parallel. An electrode and a second electrode.

A conventional angular velocity sensor having such a structure is as follows.
After forming a concave portion in the first substrate 1 and forming the detection electrode 3, a silicon substrate is bonded to the first substrate 1 by anodic bonding, and the silicon substrate is etched into a predetermined shape to form the vibrator 2. , And the first electrode 4 and the second electrode 5 are formed.

Next, the operation will be briefly described. For example, a driving unit such as a piezoelectric bimorph is used to externally drive the vibrator in both gap directions including the side surface of the vibrator 2 and the side surface of the first electrode 4 and the other side surface of the vibrator 2 and the side surface of the second electrode 5. When the vibrator 2 is driven and excited near the resonance frequency of
The capacitance between the gaps changes. When a rotational angular velocity with the longitudinal direction of the vibrator as a rotation axis system is applied to the drive excitation of the vibrator, a Coriolis force is generated in a direction orthogonal to the drive excitation direction, and the vibrator is displaced in the Coriolis force direction. Then, the capacitance between the gap formed by the transducer 2 and the detection electrode 3 on the first substrate 1 changes. Therefore, the change of the capacitance is detected by the detection means, and the rotation angular velocity is detected.

The detection of the rotational angular velocity is performed based on the following principle. A change ΔC in the capacitance C between the gap formed by the vibrator 2 and the detection electrode 3 on the first substrate 1 is detected. This △ C
Is replaced by the change ΔV of the voltage V by CV conversion. C
The -V conversion is performed according to △ V = △ C / C ₀ . Where C
₀ is the initial capacity. Since the amount of displacement of the vibrator 2 is proportional to the input angular velocity, the input angular velocity can be eventually detected from ΔV. The capacitance C is given by C = ε · s / d. Here, ε is the dielectric constant of the gap, s is the facing area between the detection electrode and the vibrator, and d is the distance between the detection electrode and the vibrator. Therefore, ΔC increases as the change in d with respect to the input angular velocity, that is, the displacement amount δ of the vibrator increases, and eventually, the initial capacitance C _0.
, That is, as the displacement amount δ of the vibrator increases, the output sensitivity increases.

In this case, the drive excitation is performed in both the gap directions including the side surface of the vibrator 2 and the side surface of the first electrode 4 and the other side surface of the vibrator 2 and the side surface of the second electrode 5. The displacement caused by the Coriolis force in a direction perpendicular to the direction of the axis is detected by the detection electrode 3. Conversely, the detection electrode 3 is used as a vibration electrode, and the gap direction formed by the lower surface of the vibrator 2 and the vibration electrode 3 is used. And the first electrode 4 and the second electrode 5 may be used as detection electrodes to detect displacement due to Coriolis force in a direction orthogonal to the drive excitation direction.

[0007]

The conventional angular velocity sensor is constructed as described above, and the displacement δ of the cantilever-shaped vibrator is the square of the length L of the vibrator with respect to the dimension of the cantilever. And inversely proportional to the width W of the vibrator. To increase the output sensitivity, increase the length L of the oscillator or the width W of the oscillator.
Needs to be smaller. Also, the initial capacitance C ₀ is
Is inversely proportional to the length G of the gap formed between the first electrode 1 and the detection electrode 3 on the first substrate 1. Therefore, in order to increase the output sensitivity, the length G of the gap needs to be as small as possible. However, when the length of the vibrator is increased, there is a disadvantage that the sensor itself becomes large and expensive. When the displacement length δ is increased by increasing the length of the vibrator, the length G of the gap cannot be reduced, and the output sensitivity cannot be increased. If the width W of the vibrator is reduced, and if the thickness of the vibrator is not reduced at the same time as the width W, a large difference occurs between the resonance frequency in the drive excitation direction and the resonance frequency in the detection direction, and the displacement δ is also small. Become. Normally, silicon is used for the vibrator, but in order to reduce the thickness of the vibrator, it is necessary to use a thin silicon substrate. However, when a thin silicon substrate is used, there are problems such as breakage of the silicon substrate during the manufacturing process, and it is difficult to produce a large-diameter wafer, and it has been difficult to obtain an inexpensive and small sensor. . Also, the first substrate 1 made of an insulating material and the silicon substrate are usually bonded by anodic bonding. However, even when an insulating material having a coefficient of thermal expansion matched to silicon is used, warpage occurs after bonding and the manufacturing process is extremely difficult. Was sometimes difficult.

The present invention has been made to solve the above-described problems, and has as its object to provide an angular velocity sensor which can be manufactured by a simple process, is small, and has high output sensitivity. Another object of the present invention is to provide a method for manufacturing the angular velocity sensor as described above.

[0009]

According to a first aspect of the present invention, there is provided an angular velocity sensor which is partially supported and fixed on a silicon substrate via an insulating film layer to form a vibrable beam. A first electrode and a second electrode, each of which has side surfaces parallel to both side surfaces of a beam portion of the vibrator, and at least a part of which is supported and fixed to the silicon substrate via an insulating film layer; Driving means for vibrating in the direction of both sides of the beam portion of the vibrator, and detecting Coriolis force generated by rotation of the vibrator, using the surface of the silicon substrate facing the beam portion of the vibrator as a third electrode. It is provided with detection means.

The angular velocity sensor according to the second configuration of the present invention is a vibrator having a part supported and fixed on a silicon substrate via an insulating film layer to form a vibrable beam, and a beam of the vibrator. First and second electrodes having side surfaces parallel to both side surfaces of the portion and at least partially supported and fixed to the silicon substrate via an insulating film layer, and opposing beam portions of the vibrator Using the surface of the silicon substrate as a third electrode,
A driving unit that vibrates the vibrator in a direction perpendicular to the surface of the silicon substrate; and a detecting unit that detects Coriolis force generated by rotation of the vibrator by the first electrode and the second electrode. is there.

Further, in the angular velocity sensor according to the third configuration of the present invention, the vibrator, the first electrode, and the second electrode each have a cantilever or a cantilever shape, and the vibrator and the first 1
The electrode and the second electrode have different resonance frequencies.

Further, in the angular velocity sensor according to a fourth configuration of the present invention, the vibrator, the first electrode, and the second electrode have a cantilever beam or a doubly supported beam shape thinner than a supporting portion that supports these. Things.

Further, in the angular velocity sensor according to the fifth aspect of the present invention, the supporting portion for supporting the first electrode and the second electrode has a shape protruding inward from the beam portion of the first electrode and the second electrode. Things.

An angular velocity sensor according to a sixth configuration of the present invention is formed of a silicon single crystal in which the surface orientation of the vibrator, the first electrode, and the second electrode is 110.

Further, in the angular velocity sensor according to a seventh aspect of the present invention, the vibrator, the first electrode, and the second electrode are vacuum-sealed using a second substrate.

In the angular velocity sensor according to an eighth aspect of the present invention, the second substrate is a silicon substrate.

Further, the method of manufacturing an angular velocity sensor according to the first method of the present invention uses a substrate provided with an insulating film layer on a silicon substrate and a silicon layer formed on the insulating film layer. A first step of processing the silicon layer by a silicon processing process to form a shape corresponding to a vibrator and first and second electrodes provided on both side surfaces of a beam portion of the vibrator; A second step of removing a part of the insulating film layer below the vibrator by etching to form a vibrating beam-shaped vibrator.

In the method of manufacturing an angular velocity sensor according to the second method of the present invention, the surface of the first silicon substrate is processed by a silicon processing process and provided on both sides of a vibrator and a beam portion of the vibrator. A first step of forming a shape corresponding to the first electrode and the second electrode to be formed, a second step of forming an insulating film layer on the surface of the processed first silicon substrate, and a first silicon substrate A third step of bonding the second silicon substrate and the second silicon substrate with the surface on which the insulating film layer is formed interposed therebetween, and polishing or etching the surface opposite to the processed surface of the first silicon substrate, A fourth step of making the silicon substrate have a required thickness, and a fifth step of removing at least a part of the insulating film layer below the vibrator by etching to form a vibrating beam-shaped vibrator. Process.

In the method of manufacturing an angular velocity sensor according to the third method of the present invention, the insulating film layer is a silicon oxide film.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, regarding Embodiment 1 of the present invention,
This will be described with reference to the drawings. FIG. 1 is a perspective view of a main part showing a schematic configuration of an angular velocity sensor according to Embodiment 1 of the present invention. FIG. 2 is a schematic diagram of the manufacturing process.
(A) is a process drawing in a section along an AA line in FIG. 1,
FIG. 2B is a process drawing in a cross section along the line BB of FIG. 1 and 2, a substrate 10 is a three-layer wafer in which an oxide film layer 10b is formed as an insulator layer on the surface of a silicon wafer 10a, and a silicon layer 10c is formed on the surface of the oxide film layer 10b. Silicon wafer is 5
Inch diameter and the thickness of the base silicon 10a is 60
The thickness of the oxide film layer 10b was 2 microns, and that of the outermost silicon layer 10c was 50 microns. Here, a silicon single crystal having a (110) plane orientation is used for the outermost silicon layer 10c. As shown in FIG. 1, a vibrator 2 partially supported and fixed and having a vibrable beam shape using such a substrate 10, and is opposed to both side surfaces of the beam portion of the vibrator 2 in parallel. The first electrode 4 and the second electrode 5 arranged on the first and second electrodes and the third electrode 3 formed on the lower surface of the vibrator 2 and serving as a Coriolis force direction detection electrode are formed to manufacture an angular velocity sensor.

Next, the manufacturing process will be described. After patterning the uppermost silicon layer 10c, TM
As shown in FIG. 1, the vibrator 2, the first electrode 4, the second electrode 5, and their supporting portions are formed by anisotropic etching with an alkaline solution of AH. Since the vibrator 2 and the first electrode 4 and the second electrode 5 are formed by the anisotropic etching technique of the silicon layer 10c having the (110) plane orientation on the substrate 10, the beam portion of the vibrator 2 is formed. , And the first electrode 4 and the second
The shape of the beam portion (longitudinal portion) of the electrode 5 in the thickness direction and the width direction can be formed with high precision. In the present embodiment, the width of the beam portion of the vibrator 2 is 50 microns, and the first electrode 4 and the second electrode 5
Was 20 microns in width. Next, the oxide film layer 10b under the vibrator 2 and under the first electrode 4 and the second electrode 5 is removed by etching with BHF. Since the oxide film layer 10b is isotropically etched in the BHF etching, the lower surfaces of the beam portions of the vibrator 2 and the support portions thereof are sufficiently wider than the beam portions of the first electrode 4 and the second electrode 5. The oxide film layer 10b remains, and the silicon layer 10
c and the base silicon 10a are electrically insulated. As the third electrode 3 serving as a detection electrode for the Coriolis force direction, the surface of the base silicon 10a exposed after removing the oxide film layer 10b by BHF etching is used.

The case where the input angular velocity is detected by the angular velocity sensor according to the present embodiment will be described. For example, the vibrator 2 is vibrated laterally from outside via a piezoelectric element or the like (not shown). Since the frequency of this vibration is set near the resonance frequency of the vibrator 2, the vibrator 2 vibrates in the horizontal direction, but the first electrode 4 and the second electrode 5 have different resonance frequencies from the resonance frequency. The amount of vibration is very small, and may be regarded as an effectively stationary state, and can be used as a reference electrode. The amount of vibration of the vibrator 2 is detected by the first electrode 4 and the second electrode 5, and is set as a reference amount of vibration. When an input angular velocity is applied from the outside while the vibrator 2 is vibrating, a vertical vibration is generated in the vibrator 2. At this time,
Since the amount of vibration is proportional to the input angular velocity, the amount of vibration is output by the third electrode 3 as a change in capacitance. This change in capacitance is detected between the vibrator 2 and the third electrode 3.

In this embodiment, the angular velocity is detected by vibrating the vibrator 2 in the horizontal direction and detecting the amount of vertical vibration when the input angular velocity is applied. Conversely, the vibrator 2 is vibrated in the vertical direction by the third electrode 3 using the third electrode 3 as the vibration electrode, and the amount of vibration in the horizontal direction when the input angular velocity is applied is determined by the first electrode. The angular velocity may be detected by detecting the fourth electrode 4 and the second electrode 5 as detection electrodes. At this time, the third electrode 3 may further detect the amount of vibration caused by the excitation and use the detected amount as the reference amount of vibration.

Further, in the present embodiment, the shape of the first electrode 4 and the second electrode 5 is a beam shape as in the case of the vibrator 2, but the width of the first electrode 4 and the second electrode 5 is the same as that of the supporting portion. It may have the same shape as the conventional one.

Embodiment 2 Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a plan view showing a schematic configuration of an angular velocity sensor according to Embodiment 2 of the present invention. FIG. 4 is a schematic diagram of the manufacturing process.
4A is a process drawing in a cross section along the line AA in FIG. 3, and FIG. 4B is a process drawing in a cross section along the line BB in FIG. 3 and 4, the substrate 10 has an oxide film layer 10b on the surface of the silicon wafer as in the first embodiment.
Is formed, and a silicon layer 10 is formed on the surface of the oxide film layer 10b.
c is a three-layer structure wafer on which c is formed. As shown in FIG. 3, a part is supported and fixed by using such a substrate 10,
A vibrator 2 having a vibrable beam shape, a first electrode 4 and a second electrode 5 arranged so as to be in parallel with both side surfaces of a beam portion of the vibrator 2, and formed on a lower surface of the vibrator 2. The third electrode 3 serving as a detection electrode for the Coriolis force direction is formed by the same manufacturing process as in the first embodiment, and an angular velocity sensor is manufactured. However, in the present embodiment, the configuration of the supporting portions of the first electrode 4 and the second electrode 5 is a configuration protruding inward from each other as shown in FIG.

Embodiment 3 FIG. Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a perspective view showing a schematic configuration of an angular velocity sensor according to Embodiment 3 of the present invention. In FIG. 5, a substrate 10 has an oxide film layer 10 on the surface of a silicon wafer 10a as in the first embodiment.
b is formed, and a silicon layer 1 is formed on the surface of the oxide film layer 10b.
0c is a three-layer structured wafer. The silicon wafer had a diameter of 5 inches, the base silicon 10a had a thickness of 600 microns, the oxide film layer 10b had a thickness of 1 micron, and the outermost silicon layer 10c had a thickness of 20 microns.
In the present embodiment, the outermost silicon layer 10c is (10
0) A silicon single crystal having a plane orientation is used. As shown in FIG. 5, a vibrator 2 partially supported and fixed and having a vibrable beam shape using such a substrate 10 is opposed to both side surfaces of the beam portion of the vibrator 2 in parallel. The first electrode 4 and the second electrode 5 arranged on the first and second electrodes and the third electrode 3 formed on the lower surface of the vibrator 2 and serving as a Coriolis force direction detection electrode are formed to manufacture an angular velocity sensor. In the present embodiment, the shape of the support portion of the vibrator 2 is a shape surrounding the angular velocity sensor as shown in FIG.

Next, the manufacturing process will be described. After patterning the outermost silicon layer 10c, dry etching by reactive ion etching is performed as shown in FIG.
The vibrator 2, the first electrode 4, the second electrode 5, and their support portions are formed as described above. In the present embodiment, the width of the beam of the vibrator 2 is 20 microns, and the width of the beam of the first electrode 4 and the second electrode 5 is 10 microns. The supporting portion of the vibrator 2 was formed so as to surround the whole. Next, the oxide film layer 10b under the vibrator 2 and under the first electrode 4 and the second electrode 5 is removed by etching with BHF. Since the oxide film layer 10b is isotropically etched in the BHF etching, the lower surfaces of the beam portions of the vibrator 2 and the support portions thereof are sufficiently wider than the beam portions of the first electrode 4 and the second electrode 5. The oxide film layer 10b remains, and the silicon layer 10c on the surface and the base silicon 10a are electrically insulated at the support portion. As the third electrode 3 serving as a detection electrode for the Coriolis force direction, the surface of the base silicon 10a exposed after removing the oxide film layer 10b by BHF etching is used. The detection of the input angular velocity is the same as in the first embodiment.

In this embodiment, since the vibrator 2, the first electrode 4 and the second electrode 5 are formed by dry etching technology, regardless of the plane orientation of the silicon layer, even if it is a polycrystalline silicon layer. An angular velocity sensor having a similar configuration can be obtained.

Embodiment 4 Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings. FIG. 6 is a perspective view showing a schematic configuration of an angular velocity sensor according to Embodiment 4 of the present invention. FIG. 7 is a schematic sectional view of a second substrate for realizing a vacuum sealing structure according to Embodiment 4 of the present invention, and is a sectional view taken along line CC in FIG. In FIG. 6, the angular velocity sensor unit 100 has the same configuration as that of the third embodiment, and is formed in the same manner as the third embodiment. The second substrate 20 is a silicon single crystal substrate having a (100) plane orientation, and has a thickness of 600 microns. After patterning, a cavity 21 is formed in a portion corresponding to the vibrator and the first and second electrodes as shown in FIG. 6 by anisotropic etching with an alkali solution of TMAH. Similarly, the support portions 4a of the first electrode 4 and the second electrode 5,
In a portion corresponding to 5a, a through-hole 22 serving as a lead-out window from each electrode is formed. Further, portions corresponding to the support portions 4a and 5a of the first electrode 4 and the second electrode 5 are oxidized to form an insulating film 23, and the support portion of the vibrator 2 and the support portion 4a of the first electrode are formed.
And the supporting portion 5a of the second electrode are insulated. Next, the first substrate 10 and the second substrate 20 are directly bonded while evacuating. When the angular velocity sensor has a vacuum sealing structure as described above, the amplitude of the vibrator in a vacuum is larger than that in the atmosphere, and the sensor sensitivity is further increased. In addition, since a silicon substrate is used as the second substrate 20, bonding with the first substrate 10 is performed by bonding silicon with each other, and warpage due to a difference in coefficient of thermal expansion at the time of bonding can be prevented. Can be provided. In addition, since the silicon substrate is used as the second substrate 20 for drawing out from each electrode, a drawing window can be formed by drilling by etching, which simplifies the manufacturing process.

Embodiment 5 FIG. 8 is a process chart showing another manufacturing process of the angular velocity sensor according to the fifth embodiment of the present invention. In the present embodiment, a single crystal silicon wafer having a (110) plane orientation is used as first substrate 30 (FIG. 8A). After patterning the single crystal silicon wafer, as shown in FIG. 8B, the vibrator 2 and the first
The electrode 4, the second electrode 5, and a shape serving as a supporting portion thereof are formed. At this time, the depth of the groove formed by etching is set to be larger than the thickness of the beam part of the final vibrator 2 and the beam part (longitudinal part) of the first electrode 4 and the second electrode 5. The width of the beam of the vibrator 2 was 32 microns, and the width of the beam of the first electrode 4 and the second electrode 5 was 12 microns. FIG. 8C shows the etched silicon wafer 30 turned upside down. After etching, this processed surface is thermally oxidized,
An oxide film layer 30a is formed on the surface (FIG. 8D). At this time, the thickness of the oxide film layer 30a was 1 micron. Next, the silicon wafer as the second substrate 31 is annealed on the first substrate 30 with the processing surface of the first substrate 30 interposed therebetween.
(FIG. 8E). Then, the first substrate 30
The thickness of the beam portion of the vibrator 2 and the beam portions (longitudinal portions) of the first electrode 4 and the second electrode 5 are finally obtained by polishing the surface opposite to the processed surface of FIG. . In this case, it was 30 microns. Next, the side surface of the vibrator 2, the side surfaces of the first electrode 4 and the second electrode 5, and the lower oxide film layer 30a are removed by etching with BHF. Since the oxide film layer 30a is isotropically etched by BHF etching, the lower surfaces of the beam portions of the vibrator 2 and the support portions thereof are sufficiently wider than the beam portions of the first electrode 4 and the second electrode 5. The oxide film layer 30a remains, and the silicon layer 30 on the surface and the silicon wafer 31 are electrically insulated at the support portion. The third electrode 3 serving as the detection electrode for the Coriolis force direction uses the surface of the silicon wafer 31 that is exposed after the oxide film layer 30a is removed by BHF etching.

In this embodiment, a silicon oxide film is used as the insulating film 30a, but it has an advantage that it can be formed only by performing an oxidation process in an oxidation furnace after the etching of the first substrate 30. Therefore, another film such as a silicon nitride film may be used as long as the film satisfies the function of the insulating film.

[0032]

As described above, according to the first structure of the present invention, a vibrator which is partly supported and fixed on a silicon substrate via an insulating film layer to form a vibrable beam shape, A first electrode and a second electrode, each of which has side surfaces parallel to both side surfaces of a beam portion of the vibrator, and at least a part of which is supported and fixed to the silicon substrate via an insulating film layer; Driving means for vibrating in the direction of both sides of the beam portion of the vibrator, and detecting Coriolis force generated by rotation of the vibrator, using the surface of the silicon substrate facing the beam portion of the vibrator as a third electrode. Since the detecting means is provided, the thickness of the vibrator can be reduced, the sensor can be downsized, and an angular velocity sensor having high output sensitivity can be obtained, and the manufacturing process can be simplified.

Further, according to the second configuration of the present invention, a vibrator partially supported and fixed on a silicon substrate via an insulating film layer to form a vibrable beam shape, and a beam portion of the vibrator A first electrode and a second electrode, each of which has a side surface parallel to both side surfaces of the first substrate and at least a part of which is supported and fixed to the silicon substrate via an insulating film layer; Driving means for vibrating the vibrator in a direction perpendicular to the surface of the silicon substrate using the surface of the silicon substrate as a third electrode; and Coriolis force generated by rotation of the vibrator by the first and second electrodes As in the above configuration, the thickness of the vibrator can be reduced, the sensor can be reduced in size, and an angular velocity sensor having high output sensitivity can be obtained, and the manufacturing process can be simplified. Become

Further, according to the third configuration of the present invention, the vibrator, the first electrode, and the second electrode each have a cantilever or doubly supported beam shape, and the vibrator and the first electrode have the same shape. Electrode and second
Since the resonance frequency with the electrode is different, an angular velocity sensor having a large output can be obtained.

According to the fourth configuration of the present invention, since the vibrator, the first electrode, and the second electrode have a cantilever beam or a doubly supported beam shape smaller than the supporting portion for supporting them. Thus, the size of the sensor can be reduced.

According to the fifth structure of the present invention, the support for supporting the first electrode and the second electrode has a shape protruding inward from the beam of the first and second electrodes. ,
Further, the size of the sensor can be reduced.

Further, according to the sixth configuration of the present invention, the vibrator, the first electrode, and the second electrode are arranged so that the plane orientation of the surface is one.
Since it is composed of ten silicon single crystals, wet etching can be used, which further simplifies the manufacturing process and ensures reliability.

According to the seventh configuration of the present invention, the vibrator, the first electrode, and the second electrode are vacuum-sealed using the second substrate, so that the output sensitivity can be further reduced. A large angular velocity sensor can be obtained.

According to the eighth structure of the present invention, since the second substrate is a silicon substrate, the bonding with the first substrate is a bonding between silicon and the difference in the coefficient of thermal expansion at the time of bonding. Can be prevented, and a vacuum sealing structure can be provided with good yield.

According to the first manufacturing method of the present invention,
Using a substrate provided with an insulating film layer and a silicon layer formed on the insulating film layer on a silicon substrate, the silicon layer is processed by a silicon processing process to form a vibrator and a beam of the vibrator. A first step of forming a shape corresponding to the first electrode and the second electrode provided on both side surfaces of the portion, and removing at least a part of an insulating film layer below the vibrator by etching to enable vibration And the second step of forming a vibrator having a simple beam shape to produce an angular velocity sensor,
A small angular velocity sensor with high output sensitivity can be manufactured in a simple process.

According to the second manufacturing method of the present invention,
A first step of processing the surface of the first silicon substrate by a silicon processing process to form a shape corresponding to the vibrator and the first and second electrodes provided on both side surfaces of the beam portion of the vibrator; A second step of forming an insulating film layer on the processed surface of the first silicon substrate; and a step of sandwiching the first silicon substrate and the second silicon substrate with the surface on which the insulating film layer is formed interposed therebetween. A third step of bonding, a fourth step of polishing or etching a surface of the first silicon substrate opposite to the processing surface to make the first silicon substrate a required thickness, and at least the vibrator And a fifth step of forming a vibrating beam-shaped vibrator by removing a part of the insulating film layer under the etching process to produce an angular velocity sensor. Thus, as in the first manufacturing method, Angular velocity sensor with small output and high output sensitivity It can be prepared in a single process.

According to the third manufacturing method of the present invention,
Since the insulating film layer is a silicon oxide film, the manufacturing process is further simplified.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part showing a schematic configuration of an angular velocity sensor according to Embodiment 1 of the present invention.

FIG. 2 is a process chart showing a manufacturing process of the angular velocity sensor according to Embodiment 1 of the present invention.

FIG. 3 is a plan view showing a schematic configuration of an angular velocity sensor according to Embodiment 2 of the present invention.

FIG. 4 is a process chart showing a manufacturing process of an angular velocity sensor according to Embodiment 2 of the present invention.

FIG. 5 is a perspective view of a main part showing a schematic configuration of an angular velocity sensor according to Embodiment 3 of the present invention.

FIG. 6 is a perspective view of a main part showing a schematic configuration of an angular velocity sensor according to Embodiment 4 of the present invention.

FIG. 7 is a schematic sectional view of a second substrate according to a fourth embodiment of the present invention.

FIG. 8 is a process chart showing another manufacturing process of the angular velocity sensor according to Embodiment 5 of the present invention.

FIG. 9 is a perspective view of a main part showing a schematic configuration of a conventional angular velocity sensor.

FIG. 10 is a sectional view of a main part showing a schematic configuration of a conventional angular velocity sensor.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 First substrate, 2 vibrator, 3rd electrode, 4th
Electrode, 5 second electrode, 4a first electrode support, 5a
Support portion of second electrode, 10 substrate, 10a base silicon, 10b oxide film layer, 10c top surface silicon layer, 20 second substrate, 21 cavity, 22 through hole, 23 insulating film, 30 first substrate, 30a oxide film layer, 31 second substrate, 100 angular velocity sensor unit.

Claims (11)

[Claims] A vibrator partly supported and fixed on a silicon substrate via an insulating film layer to form a vibrable beam shape;
A first electrode and a second electrode, each of which has side surfaces parallel to both side surfaces of a beam portion of the vibrator and at least a part of which is supported and fixed to the silicon substrate via an insulating film layer; Driving means for vibrating in the direction of both sides of the beam portion of the vibrator, and detecting Coriolis force generated by rotation of the vibrator, using the surface of the silicon substrate facing the beam portion of the vibrator as a third electrode. An angular velocity sensor, comprising: 2. A vibrator partly supported and fixed on a silicon substrate via an insulating film layer to form a vibrable beam shape;
A first electrode and a second electrode, each having a side surface parallel to both side surfaces of the beam portion of the vibrator, at least a part of which is supported and fixed to the silicon substrate via an insulating film layer; Driving means for vibrating the vibrator in a direction perpendicular to the surface of the silicon substrate using the surface of the silicon substrate facing the beam portion as a third electrode, and the first electrode and the second electrode, the vibration of the vibrator An angular velocity sensor comprising detection means for detecting a Coriolis force generated by rotation. 3. The vibrator, the first electrode, and the second electrode each have a cantilever or doubly-supported beam shape, and have different resonance frequencies between the vibrator and the first and second electrodes. The angular velocity sensor according to claim 1, wherein: 4. The angular velocity sensor according to claim 3, wherein the vibrator, the first electrode, and the second electrode have a cantilever beam or a doubly supported beam shape smaller than a supporting portion that supports them. 5. The angular velocity sensor according to claim 4, wherein the support for supporting the first electrode and the second electrode has a shape protruding inward from a beam of the first electrode and the second electrode. 6. The oscillator according to claim 1, wherein the vibrator, the first electrode, and the second electrode are made of a silicon single crystal having a surface orientation of 110 planes. Angular velocity sensor. 7. A vibrator, a first electrode, and a second electrode are connected to a second electrode.
The angular velocity sensor according to any one of claims 1 to 6, wherein the substrate is vacuum sealed. 8. The angular velocity sensor according to claim 7, wherein the second substrate is a silicon substrate. 9. A method in which a silicon substrate is provided with an insulating film layer and a silicon layer formed on the insulating film layer. A first step of forming a shape corresponding to a first electrode and a second electrode provided on both side surfaces of a beam portion of the vibrator; and etching at least a part of an insulating film layer below the vibrator by etching. And a second step of forming a vibrating beam-shaped vibrator by removing the vibrating beam-shaped vibrator. 10. A surface of a first silicon substrate is processed by a silicon processing process to form a shape corresponding to a vibrator and first and second electrodes provided on both side surfaces of a beam portion of the vibrator. A first step of forming an insulating film layer on the surface of the processed first silicon substrate;
A third step of bonding the first silicon substrate and the second silicon substrate with the surface on which the insulating film layer is formed interposed therebetween, and polishing or polishing the surface of the first silicon substrate opposite to the processed surface; A fourth step of etching to make the first silicon substrate to a required thickness, and removing at least a part of the insulating film layer below the vibrator by etching to form a vibrating beam-shaped vibrator. Forming a fifth step of forming the angular velocity sensor. 11. The method according to claim 9, wherein the insulating film layer is a silicon oxide film.