JPH10104266A - Dynamic quantity sensor and integrated circuit using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the resistance to an impact and improve the reliability by providing a displacement limiting means for limiting the displacement of the mass of a vibrating system. SOLUTION: A mass 15 fixed by a fixing part 18 through an elastic support body 17 constitutes a vibrating system on a base. A plurality of displacement limiting means 88 fixed onto the substrate so as to pass through through-holes 100 provided on the mass 15 are arranged, and a displacement limiting means 89 is provided in an empty place surrounded by the mass 15, the elastic support body 17 and the fixing part 18. The displacement limiting means 88 are used also as electrodes for detecting the y-axial displacement of the mass 15. The displacement limiting means 88 are electrically connected to each other by a polycrystalline Si wiring 40 on the substrate and collected to connecting points (a), (b). The mass 15 is also electrically connected to the polycrystalline Si wiring 40. The mass 15 and the limiting means 88 form a differential capacity circuit to detect the y-axial displacement of the mass 15. Since the displacement of the mass 15 is limited by the displacement limiting means 88, 89 according to this structure, the mass 15, even if fallen, is never relatively slipped from the detecting electrode (for which 88 is used).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a physical quantity sensor for detecting a minute force corresponding to an input of a physical quantity, for example, an acceleration sensor and an angular velocity sensor.

[0002]

2. Description of the Related Art In recent years, many electronic systems have been mounted on vehicles for improving safety and comfort. In such an electronic system, various types of control are performed on the input of the physical quantity, and thus various physical quantity sensors are required. In addition, the on-board dynamic quantity sensor is required to have a small size and low cost as well as measurement accuracy. A technology for realizing a physical quantity sensor using a semiconductor in response to such a demand is known.

FIG. 30 is a view showing a first conventional example of a semiconductor dynamic quantity sensor as described above.
FIG. 9 is a schematic plan view of an acceleration sensor described in Japanese Patent Application Publication No. 8 (JP-A-8). Hereinafter, the configuration will be described. The structures are all formed of polycrystalline silicon thin films deposited on a substrate. 1 is an inertial mass, 2 is a beam portion supporting the inertial mass on the substrate, and 3 is a comb electrode extending from a side surface of the inertial mass. Reference numerals 4 and 5 denote comb-teeth electrodes fixed to the substrate, and face the comb-teeth electrodes 3 extending from the side surface of the inertial mass. The detection electrode 6 is formed by these comb-tooth electrodes 3 to 5.

The potential of the inertial mass 1 is electrically connected to a peripheral processing circuit (not shown) from a connection point a via a beam portion 2. In addition, the comb-teeth electrode 4 extending downward from the comb-teeth electrode 3 shown in FIG.
Is connected to a peripheral processing circuit (not shown) via a connection point c. Further, the comb-teeth electrode 5 opposing the comb-teeth electrode 3 extending upward from the side surface of the inertial mass in FIG.
Is connected to a peripheral processing circuit (not shown) via a connection point b.

Next, the operation will be described. When an acceleration is input in the y-axis direction in FIG. 30, an inertial force is generated in the inertial mass 1.
The beam portion 2 bends to balance the generated inertial force, and as a result, the comb electrode 3 and the comb electrode 4 extending from the side surface of the inertial mass.
, And the distance between the comb electrode 3 and the comb electrode 5. This is detected as a capacitance difference between the connection points a and c and between the connection points a and b in FIG.

Next, FIG. 32 is a view showing an angular velocity sensor as a second conventional example, in which (a) is a schematic plan view,
(B) is a schematic sectional view taken along the line QQ 'of (a). This conventional example is described, for example, in “J. Bernstein et al.“ Micromachined
Comb-DriveTuning Fork Rate Gyroscope ”, Digest IE
EE / ASME Micro Electro Mechanical Mechanical Systems MEMS Works
hop, Florida, 1993, 143-148 ".

Hereinafter, the configuration will be described. As in the first conventional example, all the structures are formed of a polycrystalline silicon thin film deposited on the substrate 12. Reference numeral 7 denotes a vibrating mass, reference numerals 8 to 9 denote support portions for supporting the vibrating mass on the substrate 12, and reference numeral 10 denotes a drive electrode composed of a comb electrode extending from a side surface of the vibrating mass and a comb electrode fixed to the substrate. An insulating film 11 is formed on the substrate 12, and a detection electrode 13 is formed on the insulating film 11 immediately below the vibrating mass 7.

Next, the operation will be described. The two vibrating masses are applied in the x-axis direction by applying opposite-phase driving voltages to the connection points b, d and c with respect to the common potential applied from the connection point a in FIG. Each is driven in the opposite direction and vibrates. In such a driving state of the oscillating mass, when an angular velocity Ω is input in the z-axis direction in the drawing and the oscillating mass is rotated around the z-axis, the Coriolis force Fc (t) as shown by the following equation 1 is applied to each vibration. Occurs in the y-axis direction relative to mass.

Fc (t) = 2 · m · Vm (t) · Ω (Equation 1) where m: mass of the vibrating mass Vm (t): speed of the vibrating mass driven by electrostatic attraction As can be seen from equation (1), the Coriolis force Fc (t) is proportional to the speed Vm (t) of the oscillating mass. Therefore, in order to generate a larger Coriolis force, driving is normally performed at a resonance frequency in a vacuum to obtain a larger Vm (t).

Since the vibrating masses are respectively driven in opposite directions, the generated Coriolis forces have opposite signs. The vibrating mass is displaced by the generated Coriolis force in the direction normal to the substrate in the y-axis direction. This displacement causes a change in the common potential (connection point a) of the two vibrating masses and the capacitance between the respective detection electrodes. Therefore, the angular velocity can be detected by the change in the differential capacitance.

[0011]

However, in the physical quantity sensors as shown in the first and second conventional examples, the detection electrode or the drive electrode is formed by a comb-shaped electrode extending from the side surface of the displaceable mass. Since the cantilever-shaped comb-teeth electrode fixed to the substrate is configured to face the comb-teeth electrode, the comb-teeth electrode has low rigidity and can be easily displaced. And there is nothing that restrains the displacement of the vibrating mass. Therefore, it can be easily displaced particularly in the normal direction of the substrate. As a result, as shown in FIG. 31, a misstep between the comb-tooth electrodes easily occurs due to an impact force or the like generated in the case of dropping and the like, which causes an operation failure and lowers the reliability as a sensor. There was a point.

Further, since the movable part and the fixed part, such as between the vibrating mass and the substrate, between the comb-tooth electrodes, etc., are close to each other with an interval of about several μm, if dust or the like is caught, malfunctions are caused, and reliability and manufacturing yield are increased. There is a problem that causes a decrease in For this reason, although not explicitly stated in the cited document,
Usually, in order to avoid such a problem of dust, a method of covering the movable portion using a cap, a can package or the like is used. However, even with this method, there is a problem that operation failure occurs due to dust generated during the process of covering the movable portion and dust attached to the cap, can package, and the like, leading to an increase in manufacturing cost and a decrease in yield. In particular, in the angular velocity sensor as in the second conventional example, vacuum mounting is necessary to improve the sensitivity, which causes an increase in the cost of the sensor and a reduction in yield due to dust generated in the mounting process up to vacuum mounting. There was a problem that it could not be avoided.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a first object of the present invention is to provide a highly reliable dynamic quantity sensor having high strength against impacts and the like. A second object is to provide a dynamic quantity sensor which has high strength against impacts and the like, solves the inconvenience caused by dust, has high reliability, has a high production yield, and has a low production cost, and an integrated circuit using the same. To provide.

[0014]

Means for Solving the Problems In order to achieve the above object, the present invention is configured as described in the claims. That is, in the invention according to claim 1, a vibration system having a mass formed of a conductive material and an elastic support formed of a conductive material supporting the mass on a substrate, and fixed to the substrate A displacement limiting means disposed to penetrate a through hole provided in the mass, for limiting displacement of the mass, and a force generated in the mass in response to a mechanical quantity input, wherein the mass in the detection axis direction is detected. And an electrode that is electrostatically coupled to the mass that is detected as a displacement.

As described above, in the first aspect of the present invention,
Since the displacement limiting means is provided to limit the displacement of the mass of the vibration system, the strength when an impact or the like is applied can be increased, and the reliability can be improved. Incidentally, the invention of claim 1 is, for example, shown in FIG.
The present invention is applied to an acceleration sensor as described in the embodiment.

[0016] In the invention described in claim 5,
A vibrating system having a mass formed of a conductive material and an elastic support formed of a conductive material supporting the mass on a substrate, and passing through a through hole fixed to the substrate and provided in the mass; Displacement limiting means arranged to limit the displacement of the mass, and electrostatically coupled to the mass for detecting a force generated in the mass in response to a mechanical quantity input as a displacement of the mass in a detection axis direction. It is configured to include a first electrode and a second electrode electrostatically coupled to the mass for driving the mass in a direction different from the displacement detection axis direction of the mass.

As described above, the invention of claim 5 is the one in which the displacement limiting means is provided in the physical quantity sensor having the first electrode for detection and the second electrode for driving. The invention of claim 5 is applied to, for example, an angular velocity sensor as shown in an embodiment of FIG.

According to the twelfth aspect of the present invention, there is provided a vibration system having a mass formed of a conductive material and an elastic support, and a vibration system fixed to the substrate and passing through a through hole provided in the mass. A support shell, a conductive shell supported on the substrate by the support structure and forming a closed space including the vibration system with the substrate, and according to a dynamic quantity input. An electrode electrostatically coupled to the mass for detecting a force generated in the mass as a displacement of the mass in a detection axis direction, and a displacement limiting unit for limiting the displacement of the mass are provided.

According to the twelfth aspect of the present invention, there is provided a conductive shell forming a closed space enclosing a vibration system with a substrate, and a displacement limiting means. It is possible to realize a dynamic quantity sensor that solves the problems caused by dust and has high reliability, high manufacturing yield, and low manufacturing cost. In addition,
The invention of claim 12 is applied to, for example, an acceleration sensor as shown in an embodiment of FIG.

Further, in the invention according to claim 18, a vibration system having a mass formed of a conductive material and an elastic support is provided, and the vibration system is fixed to the substrate and passes through a through hole provided in the mass. A support shell, a conductive shell supported on the substrate by the support structure and forming a closed space including the vibration system with the substrate, and according to a dynamic quantity input. A first electrode electrostatically coupled to the mass for detecting a force generated in the mass as a displacement of the mass in a detection axis direction, and the mass for driving the mass in a direction different from the displacement detection axis direction of the mass. And a means for limiting displacement of the mass.

As described above, the invention of claim 18 provides a mechanical quantity sensor having a first electrode for detection and a second electrode for driving, in which a shell and displacement limiting means are provided. The invention of claim 18 is applied to, for example, an angular velocity sensor as shown in an embodiment of FIG.

According to a twenty-sixth aspect of the present invention, there is provided an integrated circuit in which the physical quantity sensor according to the twelfth to twenty-fifth aspects and a peripheral signal processing circuit are integrated on a semiconductor chip, and are molded with a resin. In the physical quantity sensor according to any one of the twelfth to twenty-fifth aspects, since the sensor is housed in the closed space formed by the shell, it is possible to perform resin molding as it is. Therefore, a low-cost and highly-reliable IC sensor can be realized by integrating a physical quantity sensor and a peripheral signal processing circuit in a closed space created by a semiconductor process on a semiconductor chip and mounting it with a resin mold or the like.

Further, in addition, claims 2 to 4, claims 6 to 11, claims 13 to 17, and claim 1
The ninth to twenty-fifth aspects are respectively the first and the fifth aspects,
Various embodiments of claims 12 and 18 are shown. These embodiments will be described later with reference to FIGS.
Each embodiment will be described.

According to a fourteenth aspect, the shell is constituted by a plurality of electrically independent regions and also serves as an electrode for detecting displacement of the mass in the detection axis direction. A first shell configured of a plurality of electrically independent regions for detecting displacement of the mass in a detection axis direction;
The configuration that also serves as the second electrode for driving the electrode or the mass is, for example, a configuration as described later in FIGS. 14 and 17, that is, an electrode (33 or the like) is provided on a shell and used for detection or The structure used for the driving electrode is shown.

[0025]

According to the first aspect of the present invention, since the displacement limiting means is provided, a relative displacement between the mass and the electrode does not occur even when an impact such as a drop is applied, and a highly reliable dynamic quantity sensor. Can be realized. In claim 2, in addition to the effect of claim 1,
By using both the displacement limiting means and the detection electrode, the effect is obtained that the configuration can be simplified, small and inexpensive.

According to the fifth aspect, the same effect as the first aspect can be obtained in a physical quantity sensor (for example, an angular velocity sensor) having a detection electrode and a drive electrode. In the sixth aspect, in addition to the effect of the fifth aspect, by using both the displacement limiting means and the first electrode for detection or the second electrode for driving, the configuration can be simplified, and the size and cost can be reduced. Is obtained.

In the ninth aspect, the height of the displacement limiting means on the substrate is set to such an extent that the mass cannot be displaced beyond the displacement limiting means, so that the displacement limiting effect in the normal direction of the substrate can be obtained. . In claim 10, since the outer shape of the end opposite to the substrate fixed end of the displacement limiting means is set to be larger than the inner diameter of the through hole, the displacement in the normal direction of the substrate is prevented without increasing the height of the displacement limiting means. A limiting effect is obtained. Claim 11
In the above, a plurality of displacement limiting means are provided, and adjacent displacement limiting means are connected so as to surround the mass between the displacement limiting means and the substrate. Is obtained.

In the twelfth aspect, since the shell and the support structure limit displacement of the mass, even when an impact such as a drop is input, a relative displacement between the mass and the electrode does not occur, and a highly reliable dynamics is achieved. A quantity sensor can be realized. In addition, since a vibration system in a closed space is formed by using a semiconductor manufacturing process, movable dust generated during the manufacturing process and during operation can be significantly suppressed as compared with the conventional method, and the manufacturing yield and dynamics can be reduced. The reliability of the quantity sensor can be improved. In addition, since a vibration system in a closed space can be formed by using a semiconductor manufacturing process, a dynamic quantity sensor can be realized with a simple mounting form, and an effect that manufacturing cost can be suppressed can be obtained. According to claims 13 and 14, in addition to the effect of claim 12, the support structure of the shell or the shell itself also serves as the displacement limiting means and the first electrode for detection or the second electrode for driving. This has the effect of simplifying the configuration, making it compact and inexpensive.

In claim 18, a physical quantity sensor (for example, an angular velocity sensor) having a detecting electrode and a driving electrode.
In this case, the same effect as the twelfth aspect is obtained. According to claim 19, by depositing the metal with the in-vacuum apparatus, it is possible to easily realize a closed space maintained in a vacuum, thereby improving the sensitivity of the angular velocity sensor and suppressing the mounting cost.
The effect is obtained.

In the twenty-first and twenty-second aspects, in addition to the effects of the eighteenth aspect, the support structure of the shell and the shell itself are provided with displacement limiting means and a first electrode for detection or a second electrode for driving. Also, the effect of simplifying the configuration, being small and inexpensive can be obtained. Claim 26
In, a physical quantity sensor in a closed space created by a semiconductor process and a peripheral signal processing circuit are integrated on a semiconductor chip, and a low-cost and highly reliable IC sensor can be realized by mounting this in a resin mold or the like. The effect is obtained.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. (First Embodiment) This embodiment is an example of an acceleration sensor according to the first, second, third, ninth, and seventeenth aspects.

First, the configuration will be described. 1A and 1B are diagrams showing a first embodiment, in which FIG. 1A is a schematic plan view, and FIG.
Is a schematic cross-sectional view taken along line LL 'of (a), and FIG.
It is M 'sectional schematic diagram. 1, a silicon oxide film 25 and a silicon nitride film 24 are deposited on a Si substrate 26 to form a substrate. On this substrate, a mass 15 fixed to the substrate by a fixing portion 18 via an elastic support 17 forms a vibration system. The elastic support 17, the fixing portion 18, and the mass 15 are formed of polycrystalline Si.

Further, a through hole 100 is provided in the mass 15, and a plurality of displacement limiting means 88 fixed on the substrate are arranged so as to penetrate the through hole 100.
A displacement limiting means 89 is provided in a space surrounded by the elastic member 5, the elastic support 17, and the fixing portion 18. This displacement limiting means 8
8, 89 are composed of a polycrystalline Si portion 44 fixed to the polycrystalline Si wiring 40 on the substrate and a polycrystalline Si portion 90 further deposited thereon. Also serves as an electrode for detecting displacement in the y-axis direction.

The height of the displacement limiting means 88, 89 is set to be sufficiently larger than the displacement of the vibration system in the normal direction of the substrate in the allowable input range to the acceleration sensor. Therefore, as long as there is no excessive input that would cause destruction, the vibration system maintains the relative position in the plane of the substrate with respect to the displacement limiting means fixed to the substrate.

The displacement limiting means 88 are electrically connected to each other by a polycrystalline Si wiring 40 on the substrate as shown in FIG. 1B, and are integrated at connection points a and b. In addition,
Details of the connection are not shown. FIG. 1B,
As shown in (c), the mass 15 is also electrically connected to the polycrystalline Si wiring 40 on the substrate via the fixing part 18 (connection point c).

The mass 15 and the displacement limiting means 88 form a differential capacitance circuit as shown in FIG. 2, and detects the displacement of the mass 15 in the y-axis direction according to the change in the capacitance value. The signal from the differential capacitance circuit is connected to a signal processing circuit (not shown) by a polycrystalline Si wiring 40 on the substrate. Note that FIG.
The symbol indicating the variable capacitance in indicates the electric capacitance (capacitance) between the mass 15 and the displacement limiting means 88.

Next, the manufacturing method of the embodiment shown in FIG. 1 will be described. 3 and 4 are schematic cross-sectional views taken along line LL 'showing the manufacturing steps of the embodiment shown in FIG. Although steps (a) to (h) in FIGS. 3 and 4 show a series of steps, they are shown separately in two drawings for convenience of illustration.

(A) After oxidizing the semiconductor Si substrate 26 to form an oxide film 25, polycrystalline Si is deposited on the oxide film 25 and then patterned to form a polycrystalline Si wiring 40. (B) A SiN film 24 is deposited on the entire surface. (C) a displacement limiting means 88 for depositing an oxide film 45 to be finally etched and removed as a sacrificial layer and fixing the oxide film 45 to a substrate;
Patterning is performed in accordance with the arrangement of 89.

(D) Deposit a polycrystalline Si film to be a part of the mass 15, the elastic support 17, the fixing part 18, and the displacement limiting means 88, 89.

(E) The polycrystalline Si film is patterned. (F) An oxide film 45 is deposited so as to flatten the patterned polycrystalline Si film, and patterning is performed in accordance with the arrangement of the displacement limiting means 88 and 89. (G) Deposit and pattern a polycrystalline Si film forming the displacement limiting means 88, 89. (H) The oxide film 45 is removed by using a hydrofluoric acid-based solution to form a vibration system including the mass 15 and the elastic support 17 and a displacement limiting unit. The acceleration sensor of FIG. 1 is formed by the steps (a) to (h).

With the above configuration, in the embodiment shown in FIG. 1, since the displacement limiting means 88 and 89 limit the displacement of the mass 15, even if an impact such as a drop is applied, There is no relative displacement between the sensor 15 and the detection electrode (also used as 88), and a highly reliable dynamic quantity sensor can be realized. In FIG. 1, the displacement limiting means 88 and 8
9, the displacement limiting means 89 may be omitted and only the displacement limiting means 88 may be provided.

(Second Embodiment) This embodiment is an example of an angular velocity sensor corresponding to claims 5, 6, 7, 10, and 24. First, the configuration will be described. 5A and 5B are diagrams showing the second embodiment, in which FIG. 5A is a schematic plan view, FIG. 5B is a schematic cross-sectional view taken along line NN ′ of FIG.
(C) is an OO ′ cross-sectional schematic view of (a).

Referring to FIG. 5, a silicon oxide
The substrate is formed by depositing the film 38 and the Si nitride film 37. L
The U-shaped elastic support 28 has a shape that can be displaced in the xy plane, and is fixed to the substrate by the fixing portion 27, and forms a vibration system with the mass 30. The resonance frequency of the vibration system in the x and y axis directions can be arbitrarily set by the structure of the elastic support 28 on the xy plane. Also, the elastic support 28, the fixing portion 2
7 and the mass 30 are formed of polycrystalline Si.

A through hole 101 is provided in the mass 30, and a displacement limiting means 91 is disposed so as to pass through the through hole 101. Further, a displacement limiting means 92 is disposed so as to penetrate a space formed by the elastic support 28, the fixing portion 27, and the mass 30. The displacement limiting means 91 and 92 are composed of a polycrystalline Si portion 46 fixed to the polycrystalline Si wiring 40 on the substrate, a silicon nitride film 36 for insulation, and a polycrystalline Si portion 93 further deposited thereon. In addition, the displacement limiting means 91 also serves as a drive electrode of the mass 30 in the x-axis direction and a displacement detection electrode in the y-axis direction.

The outer shape of the end of the displacement limiting means 91 opposite to the fixed end with respect to the substrate has a polycrystalline Si portion 93 formed in an eaves shape and is set to be larger than the inner diameter of the through hole 101. That is, the size of the portion of the displacement limiting means 91 that protrudes from the through hole 101 is set to be larger than the inner diameter of the through hole 101. Therefore, the vibration system maintains a relative position in the plane of the substrate with respect to the displacement limiting means 91 fixed to the substrate, unless there is an excessive input that would cause destruction.

The displacement limiting means 91 is electrically connected to each other by the polycrystalline Si wiring 40 as shown in FIGS. 5A and 5B, and is connected to the connection points a, b and c, d. It is put together. The details of the connection are not shown. Further, as shown in FIG. 5C, the mass 30 is also electrically connected to the polycrystalline Si wiring 40 via the fixing portion 27 (connection point e).

Four connection points a from the displacement limiting means 91,
b, c and d each constitute an electric capacitance between the mass and the connection point e of the mass 30. The mass is driven by electrostatic attraction in the x-axis direction and generated when an angular velocity is applied around the z-axis. The displacement of the mass 30 in the y-axis direction due to the Coriolis force (see Equation 1) is detected.

Next, a method of driving the mass and detecting the Coriolis force by the four electrodes facing the potential of the mass 30 as in the present embodiment will be described. These methods are described in Japanese Patent Application No. 6-31, filed by the applicant of the present invention.
No. 8158, Japanese Patent Application No. 6-304820, Japanese Patent Application No. 7-1
Since it is also described in detail in Japanese Patent No. 96404 or the like, only a basic description will be given.

FIG. 29 is a circuit diagram showing an example of the detection circuit. In FIG. 29, Cd1, Cd2, Cs1, and Cs2 respectively correspond to the following in FIG. That is, Cd1 is the electric capacity between the connection points a and e, Cd2 is the electric capacity between the connection points b and e, Cs1 is the electric capacity between the connection points c and e, and Cs2 is the electric capacity between the connection points d and e. It corresponds to the electric capacity between the connection points e.

By applying a predetermined drive voltage to the drive electrode terminals Vd1 and Vd2 alternately with respect to the potential Vm of the mass 30, the mass 30 is driven to vibrate in the x-axis direction. The resonance frequency fxr of the vibrating mass 30 in the x-axis direction is determined by the mass of the mass 30 and the spring constant of the support 28 in the x-axis direction. Therefore, the resonance state can be easily realized by electrically adjusting the applied frequency of the drive power supply OSC1.

For accurate Coriolis force measurement, the mass 3
It is necessary to drive 0 at a constant frequency and a constant amplitude. Since the vibration frequency matches the drive frequency, the frequency of the drive power supply OSC1 may be kept constant. For constant amplitude control, for example, a configuration as shown in FIG. 29 may be used. That is, the reference electric capacity Cr2 is connected in series between each drive electrode end Vd1, Vd2 and the drive power supply OSC1.

The impedance Zc of the electric capacitance is expressed by the following (Equation 2). Zc = 1 / jωC (Equation 2) Therefore, the reference electric capacity Cr2 is set to each driving electrode end and the mass 3
If the electric capacitances Cd1 and Cd2 are sufficiently larger than zero, the loss in the driving voltage Cr2 can be almost ignored. Since the actual values of Cd1 and Cd2 are about pF, it is easy to realize Cr2 even on the same substrate.

Driving voltages D, D via the reference capacitance Cr2
(Underline indicates an inverted voltage of D), the potentials of the drive electrode terminals Vd1 and Vd2 are passed through the buffer 163, and the differential signal is driven by the demodulator 162 to drive the drive power supply OSC1. If the detection is performed in synchronization with the frequency, information on the vibration amplitude of the mass 30 can be obtained. Therefore, by applying negative feedback to the drive power supply OSC1 so that the obtained amplitude information becomes a predetermined value, the mass 30
Can be driven at a constant amplitude.

Next, a method for detecting a change in the capacitance of the detection electrode pair due to the Coriolis force represented by the above-mentioned formula (1) may be performed, for example, as shown in FIG. That is, a reference electric capacitance C substantially equal to the electric capacitance between each detection electrode and the mass 30 is provided between each detection electrode end Vs1, Vs2 and the detection power supply OSC2 (power supply having a frequency sufficiently higher than the drive power supply OS1).
Connect r1 in series. When the detection voltage C is applied via the reference capacitance Cr1, the potentials of the detection electrode terminals Vs1 and Vs2 are detected via the buffer 163, and the differential signals thereof are detected by the demodulator 162 in synchronization with the frequency of the detection power supply OSC2. Then, the amount of displacement in the y-axis direction due to the Coriolis force that changes with the frequency of the drive power supply OSC1 is obtained. Therefore, as shown in FIG. 29, if the signal is processed again in synchronization with the driving frequency of the driving power supply OSC1, the DC corresponding to the displacement amount in the y-axis direction can be obtained.
A signal is obtained.

A DC disturbance acceleration input in the x-axis direction affects the output as a change in the vibration amplitude of the mass 30. This effect can be eliminated by monitoring the vibration amplitude and adopting a configuration as shown in FIG. 29 to make it constant.

Further, a DC disturbance acceleration input in the z-axis direction affects the output as a change in the vibration amplitude of the mass 30 and a change in the facing area of the detection electrode. The influence due to the change in the vibration amplitude can be removed by the same method as in the x-axis direction. The effect on the output due to the change in the facing area of the detection electrodes can be eliminated by the configuration as shown in FIG. 29 for detecting the differential capacitance of the detection electrode pair.

The input of the disturbance acceleration in the DC y-axis direction is performed by using the two angular velocity sensors of this embodiment as a pair, driving the respective masses 30 in opposite phases, and calculating the difference between the outputs of the respective angular velocity sensors. It can be removed by taking a motion signal, and more accurate angular velocity detection can be performed. In addition, by taking the sum signal of the outputs of the angular velocity sensors, it is possible to detect a DC external acceleration input in the detection axis direction (y-axis direction).

Further, with respect to the AC disturbance acceleration input in the x and y axis directions, the vibration due to resonance is induced in the x axis direction and the y axis direction to affect the output, but the resonance frequency in each axis direction is sufficiently increased. If it is designed to be high, a low-pass filter can be formed by the mounting structure of the sensor to suppress the input of AC disturbance acceleration.

If the driving and signal processing circuits for the detection section as shown in FIG. 29 are formed on the same substrate, the influence of extraneous noise mixed while a minute generated signal is input to the processing circuit is greatly reduced. it can. Also, the reference electric capacity Cr1 pair,
The pairing of the electric capacity of the Cr2 pair can be improved, and the driving force and the offset of the output signal can be reduced.

Next, a manufacturing method of the embodiment shown in FIG. 5 will be described. 6 and 7 are NN 'cross-sectional schematic views showing the manufacturing steps of the embodiment shown in FIG. Although steps (a) to (h) in FIGS. 6 and 7 show a series of steps, they are shown separately in two drawings for convenience of illustration. The basic process flow is almost the same as the first embodiment.

(A) After oxidizing the semiconductor Si substrate 39 to form an oxide film 38, a polycrystalline Si wiring 40 is deposited and patterned. (B) A silicon nitride film 37 is deposited on the entire surface. (C) An oxide film 47 serving as a sacrifice layer is deposited and patterned in accordance with the connection with the polycrystalline Si wiring 40. (D) A polycrystalline Si film serving as the mass 33, the elastic support 28, the fixing portion 27, and the displacement limiting means 91 is deposited, and then a Si nitride film 36 is entirely deposited and patterned according to the displacement limiting means 91.

(E) The polycrystalline Si film is patterned in accordance with the mass 33, the elastic support 28, the fixing portion 27, and the displacement limiting means 91. (F) After depositing an oxide film 47 so as to flatten the patterned polycrystalline Si film, patterning is performed in accordance with the displacement limiting means 91. (G) A polycrystalline Si film is deposited and patterned into an outer shape larger than the through hole having a mass of 30. (H) The oxide film 47 is removed using a hydrofluoric acid-based solution to form a vibration system including the mass 30 and the elastic support 28. Through the above steps, the angular velocity sensor shown in FIG. 5 is formed.

With the configuration described above, the second embodiment shown in FIG. 5 has the following effects in addition to the effects of the first embodiment. (1) The outer shape of the end of the displacement limiting means 91 opposite to the substrate fixed end (the portion protruding upward from the mass 30) is defined by the through hole 101.
Is set larger than the inner diameter of the substrate, the effect of limiting the displacement in the normal direction of the substrate can be obtained without increasing the height of the displacement limiting means 91. (2) By driving the physical quantity sensors according to the present embodiment in pairs in the same manner as in the second conventional example and in opposite phases, and obtaining the differential signal of the output, the influence of the disturbance acceleration can be further removed. Highly accurate angular velocity measurement becomes possible.

(Third Embodiment) This embodiment relates to claims 1, 2, 3, 11, and 17 of the present invention.
Is equivalent to First, the configuration will be described. FIGS. 8A and 8B are diagrams showing the third embodiment, wherein FIG. 8A is a schematic plan view, and FIG.
1 is a schematic cross-sectional view taken along the line PP ′ of FIG. The planar structure of the present embodiment is almost the same as that of the first embodiment, and only the cross-sectional structure is different from that of the first embodiment.

Referring to FIG. 8, a silicon oxide
The substrate is formed by depositing the film 25 and the Si nitride film 24. On this substrate, a mass 15 fixed to the substrate by a fixing portion 18 via an elastic support 17 forms a vibration system. The elastic support 17, the fixing portion 18, and the mass 15 are formed of polycrystalline Si.

Further, a through hole 100 is provided in the mass 15, and a displacement limiting means 88 fixed on a substrate is disposed so as to penetrate the through hole 100, and further, the mass 15, the elastic support 17, and the fixing portion A displacement limiting means 89 is provided in a space surrounded by the reference numeral 18. The displacement limiting means 88, 8
9 includes a polycrystalline Si portion 44 fixed to the polycrystalline Si wiring 40 on the substrate, and a polycrystalline Si portion 90 further deposited thereon.
Also serves as an electrode for detecting the displacement in the y-axis direction.

As shown in FIG. 8B, a plurality of displacement limiting means 88 arranged on the substrate are connected such that adjacent displacement limiting means 88 surround the mass 15 between the displacement limiting means 88 and the substrate. I have. That is, the adjacent displacement limiting means 88
The portion protruding from the through hole 100 is a polycrystalline Si portion 90.
, And has a shape surrounding the mass 15. Therefore, the vibration system maintains the relative position in the plane of the substrate with respect to the displacement limiting means fixed to the substrate, unless there is an excessive input that may cause destruction.

The displacement limiting means 88 is electrically connected to each other by the polycrystalline Si wiring 40 on the substrate as shown in FIG. 8B, and is integrated at connection points a and b. In addition,
Details of the connection are not shown. The mass 15 is also electrically connected to the polycrystalline Si wiring 40 on the substrate via the fixing portion 18 (connection point c).

The mass 15 and the displacement limiting means 88 are the same as those shown in FIG.
A differential capacitance circuit is formed as shown in (1), and the displacement of the mass 15 in the y-axis direction is detected according to the change in the capacitance value. The signal from the differential capacitance circuit is connected to a signal processing circuit (not shown) by a polycrystalline Si wiring 40 on the substrate. In addition,
The reference numeral indicating the variable capacitance in FIG. 2 indicates the electric capacitance between the mass 15 and the displacement limiting means 88.

Next, the manufacturing method of the embodiment shown in FIG. 8 will be described. 9 and 10 are schematic cross-sectional views taken along the line PP 'showing the manufacturing steps of the embodiment shown in FIG. Although steps (a) to (h) in FIGS. 9 and 10 show a series of steps, they are shown separately in two drawings for convenience of illustration.

(A) After oxidizing the semiconductor Si substrate 26 to form an oxide film 25, polycrystalline Si is deposited on the oxide film 25 and then patterned to form a polycrystalline Si wiring 40. (B) A SiN film 24 is deposited on the entire surface. (C) An oxide film 45 to be finally removed by etching as a sacrificial layer is deposited, and patterning is performed in accordance with the arrangement of the displacement limiting means 89 fixed to the substrate. (D) Deposit a polycrystalline Si film serving as a part of the mass 15, the elastic support 17, the fixing part 18 and the displacement limiting means 89.

(E) The polycrystalline Si film is patterned. (F) An oxide film 45 is deposited so as to flatten the patterned polycrystalline Si film, and patterning is performed in accordance with the arrangement of the displacement limiting means 89. (G) Deposit and pattern a polycrystalline Si film forming the displacement limiting means 89. (H) The oxide film 45 is removed by using a hydrofluoric acid-based solution to form a vibration system including the mass 15 and the elastic support 17 and a displacement limiting unit. Through the above steps, the acceleration sensor shown in FIG. 8 is formed.

With the above configuration, the third embodiment shown in FIG. 8 has the following effects in addition to the effects of the first embodiment. (1) Since the plurality of displacement limiting means 88 arranged on the substrate are connected so that the adjacent displacement limiting means 88 surround the mass 15 between the displacement limiting means 88 and the substrate, the displacement limiting means 89 is provided.
The effect of limiting the displacement in the normal direction of the substrate can be obtained without increasing the height of the substrate.

(Fourth Embodiment) This embodiment is an example of an acceleration sensor according to the twelfth, thirteenth, fifteenth, seventeenth, and twenty-sixth aspects. First, the configuration will be described. 11A and 11B are diagrams showing a fourth embodiment, in which FIG. 11A is a schematic plan view, FIG. 11B is a schematic cross-sectional view taken along the line AA ′ of FIG. It is a B 'cross section schematic diagram.

Referring to FIG. 11, an oxidized S
The substrate is formed by depositing the i film 25 and the Si nitride film 24.
A shell 102 composed of a polycrystalline Si film 20 and a Si nitride film 21 is formed on the substrate, and forms a closed space with the substrate. In the closed space, a mass 15 fixed to the substrate by a fixing portion 18 by an elastic support 17 forms a vibration system. Those elastic supports 17 and fixing portions 18
And the mass 15 is formed of polycrystalline Si.

Further, a through hole 100 is provided in the mass 15, a support structure 16 fixed on the substrate is provided so as to penetrate the through hole 100, and the mass 15, the elastic support 17 and the fixing portion A support structure 19 is provided in a space surrounded by the support structure 18. The shell 102 is supported on a substrate by the support structures 16 and 19. The support structure 16 includes a polycrystalline Si portion 44 fixed to the substrate and a metal portion 22 penetrating through the Si nitride film layer 21 of the shell 102, and detects displacement of the mass 15 in the y-axis direction. Also serves as an electrode.

The support structures 16 are electrically connected to each other by the metal portions 22 as shown in FIG.
They are summarized at connection points a and b. The details of the connection are not shown. Further, as shown in FIGS. 1B and 1C, the mass 15 is also electrically connected to the metal part 23 via the fixing part 18 (connection point c). Also, the shell 102
Is also electrically connected (connection point c) at the metal part 23. Therefore, the mass 15 and the polycrystalline Si film 20 forming the shell 102 are electrically connected to each other.

Further, the mass 15 and the support structure 16 form a differential capacitance circuit as shown in FIG. 2, and the displacement of the mass 15 in the y-axis direction is detected from a change in the capacitance value. A signal from the differential capacitance circuit is connected to a signal processing circuit (not shown) via a metal part 22 and a metal part 23. Note that the reference numeral indicating the variable capacitance in FIG. 2 indicates the electric capacitance between the mass 15 and the support structure 16.

Next, a manufacturing method of the embodiment shown in FIG. 11 will be described. 12 and 13 are schematic cross-sectional views taken along the line AA 'showing the manufacturing process of the embodiment shown in FIG. Although steps (a) to (i) in FIGS. 12 and 13 show a series of steps, they are shown separately in two drawings for convenience of illustration.

(A) After oxidizing the semiconductor Si substrate 26 to form the oxide film 25, the Si nitride film 24 is deposited on the entire surface. (B) An oxide film 45 to be finally removed by etching as a sacrificial layer is deposited, and patterning is performed in accordance with the arrangement of the support structure 16 of the shell fixed to the substrate. (C) A polycrystalline Si film serving as the mass 15, the elastic support 17, the fixing portion 18 and the support structure 16 of the shell is deposited and patterned. (D) An oxide film 45 is deposited so as to flatten the patterned polycrystalline Si film.

(E) Patterning is performed to form a closed space for forming the deposited oxide film 45, and a polycrystalline Si film 20 for forming a shell is deposited and patterned. (F) The polycrystalline Si film 20 of the shell is patterned according to the support structure 16, and a SiN film 21 is further deposited on the entire surface. (G) The Si nitride film 21 is patterned according to the metal part 22 forming the support structure 16. (H) The oxide film 45 is removed using a hydrofluoric acid-based solution to form a vibration system including a closed space, a mass 15 and an elastic support 17 in the shell. When the oxide film 45 is removed, the space around the shell supporting structure 16 penetrating the mass 15 also functions as an etching hole. (I) A metal is deposited on the entire surface and patterned. Through the above steps, the acceleration sensor shown in FIG. 11 is formed.

With the above configuration, the following effects can be obtained in the fourth embodiment. (1) Since the support structure 16 of the shell 102 also serving as the displacement detection electrode limits the displacement of the mass 15, even if an impact such as a drop is input, the relative displacement between the mass and the electrode does not occur. A highly reliable physical quantity sensor can be realized. (2) Since a vibration system in a closed space is formed by using a semiconductor manufacturing process, movable dust generated during the manufacturing process and during operation can be significantly suppressed as compared with the conventional method, and the manufacturing yield and The reliability of the physical quantity sensor can be improved. (3) By setting the mass forming the vibration system and the polycrystalline Si forming the shell to have a common potential, the electrostatic force generated in the mass can be suppressed, and external electrical noise exerted on the differential capacitance detection unit. Can be suppressed. In particular, this effect is large when a minute change in capacitance value is measured. (4) Since a vibration system in a closed space is formed using a semiconductor manufacturing process, a dynamic quantity sensor can be realized with a simple mounting form, and a reduction in manufacturing cost can be realized. (5) In this embodiment, since the sensor is housed in the closed space formed by the shell, it is possible to perform resin molding as it is. Therefore, a low-cost, highly-reliable IC can be obtained by integrating a dynamic quantity sensor and a peripheral signal processing circuit in a closed space created by a semiconductor process as in the present embodiment on a semiconductor chip and mounting it with a resin mold or the like. A sensor can be realized.

(Fifth Embodiment) This embodiment relates to an angular velocity sensor corresponding to claims 18, 19, 20, 20, 21, 22, 24 and 26. It is an example. First, the configuration will be described. FIG.
It is a diagram showing an embodiment of the present invention, (a) is a schematic plan view,
(B) is a schematic cross-sectional view taken along the line CC ′ of (a), (c) is (a)
It is DD 'cross section schematic diagram of.

Referring to FIG. 14, an oxidized S
The substrate is formed by depositing the i film 38 and the Si nitride film 37.
A shell 102 composed of a polycrystalline Si film 35 and a Si nitride film 34 is formed on the substrate, and forms a closed space with the substrate.

In the closed space, a mass 30 fixed to the substrate by the fixing portion 27 by an L-shaped elastic support member 28 displaceable in the xy plane forms a vibration system. The resonance frequency of the vibration system in the x and y axis directions is xy of the elastic support 28.
It can be set arbitrarily depending on the structure on the plane. The elastic support 28, the fixing portion 27 and the mass 30 are formed of polycrystalline Si.

The shell 102 is provided with a support structure 2 disposed so as to pass through a through hole 101 provided in the mass 30.
9 and 32 are supported on the substrate. The support structure 32 includes a polycrystalline Si portion 46 fixed to a polycrystalline Si wiring 40 on the substrate, a metal portion 41 penetrating the insulating Si nitride film 36 and the shell Si nitride film layer 34. Also, it serves as both a drive electrode in the x-axis direction of the mass 30 and a displacement detection electrode in the y-axis direction.

The support structure 32 is electrically connected to each other by the polycrystalline Si wiring 40 as shown in FIGS. 14A and 14B, and is integrated into connection points a and b and c and d. ing. The details of the connection are not shown. In addition, as shown in FIG.
Similarly, it is electrically connected to the polycrystalline Si wiring 40 on the substrate (connection point e). Further, the polycrystalline Si film 35 constituting the shell 102 is also electrically connected (connection point e) by the polycrystalline Si wiring 40. Therefore, mass 30
And the polycrystalline Si film 35 forming the shell 102 are electrically connected to each other.

As shown in FIG. 14C, an electrode 33 formed by a polycrystalline Si film (a broken line in FIG. 14A) is formed on the Si nitride film 34 constituting the shell 102. And electrostatically opposes the mass 30. An electrode 42 made of polycrystalline Si wiring is formed on the substrate immediately below the electrode 33, and faces the mass 30.
The electrode 33 is electrically connected to the connection point f, and the electrode 42 is electrically connected to the connection point g.

The four connection points a, b, c and d of the support structure 32 respectively constitute electric capacitances with the connection point e of the mass 30, and are formed by electrostatic attraction of the mass in the x-axis direction. While driving, y is determined by the Coriolis force (see Equation 1) generated when an angular velocity is input around the z-axis.
The displacement of the mass 30 in the axial direction is detected. The driving of the mass and the detection of the Coriolis force by the four electrodes facing the potential of the mass are the same as those described in the second embodiment.

The electrodes 33 and 42 facing the mass 30
Constitutes a differential capacitance circuit in the same manner as in the fourth embodiment, and is capable of detecting displacement of the mass in the z-axis direction and generating electrostatic attraction to the mass. Therefore, the electrodes 33 and 42 can be used for detecting acceleration in the z-axis direction, controlling vibration of the mass 30 in the z-axis direction, and the like.

It should be noted that, as in the present embodiment, the physical quantity sensor and the peripheral signal processing circuit in the closed space created by the semiconductor process are integrated on a semiconductor chip, and this is mounted at low cost by resin molding or the like. As in the fourth embodiment, a highly reliable IC sensor can be realized.

Next, the manufacturing method of the embodiment shown in FIG. 14 will be described. 15 and 16 are schematic cross-sectional views taken along the line CC 'showing the manufacturing steps of the embodiment shown in FIG. Although steps (a) to (h) in FIGS. 15 and 16 show a series of steps, they are shown separately in two drawings for convenience of illustration. The basic process flow is almost the same as that of the fourth embodiment.

(A) After oxidizing a semiconductor Si substrate 39 to form an oxide film 38, a polycrystalline Si wiring 40 is deposited and patterned. (B) A silicon nitride film 37 is deposited on the entire surface. (C) An oxide film 47 serving as a sacrificial layer is deposited and patterned in accordance with the connection with the polycrystalline Si wiring 40. (D) A polycrystalline Si film serving as the mass 30, the elastic support 28, the fixing portion 27, and the support structure 32 of the shell is deposited, and then a Si nitride film 36 is deposited on the entire surface to conform to the support structure 32 of the shell. To perform patterning.

(E) The polycrystalline Si film is patterned according to the mass 30, the elastic support 28, the fixing portion 27 and the support structure 32 of the shell. (F) After depositing an oxide film 47 so as to flatten the patterned polycrystalline Si film, the polycrystalline Si film 3 is patterned into a closed space to be formed, and further forms a shell.
5 is deposited and patterned. (G) The polycrystalline Si film 35 of the shell is patterned according to the support structure 32, and a Si nitride film 34 is further deposited on the entire surface, and the Si nitride film 34 is formed according to the metal portion 41 forming the support structure 32. Perform patterning. (H) The oxide film 47 is removed by using a hydrofluoric acid-based solution to form a vibration system including a closed space, a mass 30, and an elastic support 28 in the shell. Then, a metal is deposited on the entire surface and patterned. When the oxide film 47 is removed, the space around the shell support structure 32 penetrating the mass 30 also functions as an etching hole. Through the above steps, the angular velocity sensor shown in FIG. 14 is formed.

With the above configuration, the following effects can be obtained in the fifth embodiment in addition to the effects of the fourth embodiment. (1) In the step (h), by depositing a metal with an in-vacuum apparatus, it is possible to easily realize a closed space maintained in a vacuum, thereby improving the sensitivity of the angular velocity sensor and suppressing the mounting cost. (2) By driving the physical quantity sensors according to the present embodiment in pairs in the same manner as in the second conventional example and in opposite phases, and obtaining the differential signal of the output, the influence of the disturbance acceleration can be further removed. Highly accurate angular velocity measurement becomes possible.

(Sixth Embodiment) This embodiment is an example of an angular velocity sensor corresponding to claims 18, 19, 20, 21, 22, 24, and 26. First, the configuration will be described.
FIGS. 17A and 17B are views showing the sixth embodiment, wherein FIG. 17A is a schematic plan view, and FIG. 17B is a schematic cross-sectional view taken along the line EE ′ of FIG.

Referring to FIG. 17, an oxidized S
The substrate is formed by depositing the i film 38 and the Si nitride film 37.
A shell 102 composed of a polycrystalline Si film 35 and a Si nitride film 34 is formed on the substrate, and forms a closed space with the substrate. In the closed space, a mass 30 fixed to the substrate by the fixing portion 27 by an elastic support member 28 displaceable in an L-shaped xy plane forms a vibration system. The resonance frequency of the vibration system in the x and y axis directions is
It can be set arbitrarily depending on the structure on the −y plane. The elastic support 28, the fixing part 27 and the mass 30 are made of polycrystalline Si.
Is formed.

The shell 102 is provided with a support structure 2 disposed so as to pass through a through hole 100 provided in the mass 30.
9 and 32 are supported on the substrate. The supporting structure 32 is composed of a polycrystalline Si portion 46 fixed to a polycrystalline Si wiring 40 on the substrate, a metal portion 41 penetrating the insulating Si nitride film 36 and the shell Si nitride film layer 34. , 30 also serves as an electrode for detecting the displacement of the mass 30 in the y-axis direction.

The support structure 32 is electrically connected to each other by the polycrystalline Si wiring 40 as shown in FIG. 17A, and is integrated at connection points f and g. The details of the connection are not shown. Also, as shown in FIG. 17B, the mass 30 is similarly electrically connected to the polycrystalline Si wiring 40 on the substrate via the fixing portion 27 (connection point e). Further, the polycrystalline Si film 35 constituting the shell 102
Are also electrically connected (connection point e) by the polycrystalline Si wiring 40. Therefore, the mass 30 and the polycrystalline Si film 35 forming the shell 102 are electrically connected to each other.

Also, as shown in FIG. 17B, electrodes 33 and 33 ′ made of a polycrystalline Si film are formed on the Si nitride film 34 constituting the shell 102 [broken lines in FIG. 17A]. Are formed, and are electrostatically opposed to the mass 30. Electrodes 42 and 42 ′ formed of polycrystalline Si wiring are formed on the substrate immediately below the electrodes 33 and 33 ′, and face the mass 30. The electrodes 33 and 33 'are connected to connection points a and c, and the electrodes 42 and 42' are connected to connection points b and d.
Each is electrically connected.

The four connection points a, b, c and d formed by the electrodes 33, 33 ', 42 and 42' constitute electric capacitances with the connection point e of the mass 30, respectively. In addition to driving by electrostatic attraction in the direction, the Coriolis force generated when an angular velocity is input around the z-axis (the above equation (1))
The displacement of the mass 30 in the y-axis direction is detected by the equation (see formula).
The driving of the mass and the detection of the Coriolis force by the four electrodes facing the potential of the mass are the same as those described in the second embodiment.

The electrode (support structure) 32 facing the mass 30 forms a differential capacitance circuit similarly to the fourth embodiment, and detects displacement of the mass in the z-axis direction and statically responds to the mass. It is possible to generate an attractive force. Accordingly, the electrode 32 can be used for detecting acceleration in the z-axis direction, controlling vibration of the mass 30 in the z-axis direction, and the like.

It should be noted that, as in the present embodiment, the physical quantity sensor and the peripheral signal processing circuit in the closed space created by the semiconductor process are integrated on a semiconductor chip, and this is mounted at low cost by resin molding or the like. As in the fourth embodiment, a highly reliable IC sensor can be realized.

Next, the manufacturing method of the embodiment shown in FIG. 17 will be described. FIG. 18 is a schematic cross-sectional view along the line EE 'showing the manufacturing process of the embodiment shown in FIG. Since the basic process flow is almost the same as that of the fifth embodiment, detailed description will be omitted.

With the above configuration, the following effects can be obtained in the sixth embodiment in addition to the effects of the fifth embodiment. (1) Compared with the fifth embodiment, since the integration degree of the displacement detection electrodes of the mass 30 which also serves as the support structure of the shell can be improved, higher S / N ratio detection is possible. (2) By driving the physical quantity sensors according to the present embodiment in pairs in the same manner as in the second conventional example and in opposite phases, and obtaining the differential signal of the output, the influence of the disturbance acceleration can be further removed. Highly accurate angular velocity measurement becomes possible.

(Seventh Embodiment) This embodiment is an example of an acceleration sensor according to the twelfth, thirteenth, sixteenth, seventeenth, and twenty-sixth aspects. First, the configuration will be described. FIGS. 19A and 19B are diagrams showing the seventh embodiment, in which FIG. 19A is a schematic plan view, FIG. 19B is a schematic cross-sectional view taken along line FF ′ of FIG. It is a G 'cross section schematic diagram.

In this embodiment, a mechanical quantity sensor is formed using an SOI substrate using an oxide film layer and a Si nitride layer patterned as a dielectric isolation layer. That is, in FIG. 19, on an SOI substrate 62 including a base substrate 61, a Si nitride film 60 and an SOI layer 59,
The substrate is formed by depositing the Si oxide film 58 and the Si nitride film 63. A shell 103 composed of a polycrystalline Si film 54 and a Si nitride film 53 is formed on the substrate, forming a closed space with the substrate. In the closed space, a mass 48 fixed to the substrate by the fixing portion 51 by the elastic support 50 forms a vibration system. These elastic supports 50 and fixing portions 51
The mass 48 is formed by trench etching the SOI layer 59.

The shell 103 is provided with a support structure 4 arranged so as to pass through a through hole 100 provided in the mass 48.
9 and 52 are supported on the substrate. The support structure 49 is composed of a SOI layer portion 55 formed by trench etching and a metal portion 56 penetrating through the Si nitride film layer 53 of the shell, which is fixed on the base substrate 61 by the Si nitride layer 60, The electrode also serves as an electrode for detecting the displacement of the mass 48 in the y-axis direction.

The support structure 49 is electrically connected to each other by the metal part 56 as shown in FIG.
They are summarized at connection points a and b. The details of the connection are not shown. Also, as shown in FIGS. 19B and 19C, the mass 48 is similarly connected to the metal portion 5 via the fixing portion 51.
6 is electrically connected (connection point c). Further, the polycrystalline Si film 54 constituting the shell 103 is also electrically connected to the metal part 57 (connection point c). Therefore, the mass 48 and the polycrystalline Si film 54 forming the shell 103 are electrically connected to each other.

Further, the mass 48 and the supporting structure 50 form a differential capacitance circuit as shown in FIG. 2, and detects the displacement of the mass 48 in the y-axis direction according to the change of the capacitance value. The signal from the differential capacitance circuit is connected to a signal processing circuit (not shown) via metal parts 56 and 57.

As described in the present embodiment, the physical quantity sensor and the peripheral signal processing circuit in the closed space created by the semiconductor process are integrated on a semiconductor chip, and this is mounted at low cost by resin molding or the like. As in the fourth embodiment, a highly reliable IC sensor can be realized.

Next, a manufacturing method of the embodiment shown in FIG. 19 will be described. 20 and 21 are schematic cross-sectional views taken along the line FF 'showing the manufacturing steps of the embodiment shown in FIG. Although steps (a) to (h) in FIGS. 20 and 21 show a series of steps, they are shown separately in two drawings for convenience of illustration.

(A) An SOI substrate having an oxide film layer and a Si nitride film layer on which a dielectric isolation layer is patterned is used. (B) The SOI substrate is oxidized to form an oxide film 58, a Si nitride film 63 is deposited on the entire surface, and patterned in accordance with the trench etching. Thereafter, trench etching is performed until the dielectric isolation layer is reached. (C) Deposit an oxide film to flatten the trench etching portion, and remove the Si nitride film 63 in a region where a vibration system is to be formed. (D) After depositing the oxide film 64, patterning is performed in accordance with the shape of the closed space to be formed.

(E) Polycrystalline Si forming shell 103
A film 54 is deposited and patterned. (F) The polycrystalline Si film 54 of the shell is patterned according to the support structure 49, and a Si nitride film 53 is further deposited on the entire surface, and the Si nitride film 53 is formed according to the metal part 56 forming the support structure 49. Perform patterning. (H) The oxide film 64 is removed using a hydrofluoric acid-based solution to form a vibration system including a closed space, a mass 48 and an elastic support 50 in the shell, and then a metal is deposited on the entire surface and patterned. When the oxide film 64 is removed, the space around the support structure 49 penetrating the mass 48 also functions as an etching hole. Through the above steps, the acceleration sensor shown in FIG. 19 is formed.

With the configuration described above, the following effects can be obtained in the seventh embodiment as compared with the fourth embodiment. (1) Since the SOI layer made of single-crystal Si is used, a vibration system can be created more stably than in the case of using a polycrystalline Si layer. (2) Since the vibration system is formed by trench etching the SOI layer, the thickness of the structural material can be increased without increasing the step on the substrate surface. Therefore, the capacitance value increases, and detection with a higher S / N ratio becomes possible.

(Eighth Embodiment) The present embodiment is an example of an acceleration sensor according to claims 12, 13, 17, 15, and 26. 22 and 23 are views showing the eighth embodiment, wherein FIG. 22 (a) is a schematic plan view, FIG. 22 (b) is a schematic sectional view taken along the line HH ′ of FIG.
FIG. 23A is a schematic cross-sectional view taken along the line II ′ of FIG.
FIG. 23B is a schematic cross-sectional view taken along the line JJ ′ of FIG.
FIG. 23C is a schematic sectional view taken along the line KK ′ of FIG.

In this embodiment, a mechanical quantity sensor is formed using an SOI substrate using an oxide film layer and a Si nitride layer patterned as a dielectric isolation layer. That is, in FIG. 22, on a SOI substrate 79 including a base substrate 78, a Si nitride layer 77, and an SOI layer 76,
The substrate is formed by depositing the Si oxide film 75 and the Si nitride film 69. A shell 103 composed of a polycrystalline Si film 71 and a Si nitride film 70 is formed on the substrate, and forms a closed space with the substrate.

In the closed space, a mass 72 fixed by the fixing portion 65 by the elastic support 66 forms a vibration system. The elastic support 66 and the mass 72 are formed of polycrystalline Si deposited in a trench 82 formed by etching the SOI layer. This forming method uses a polycrystalline Si film serving as a trench portion 82 as shown in a process flow described later.
After the deposition, trench etching of other portions and deposition of polycrystalline Si in the trench are performed. The fixing portion 65 is made of polycrystalline Si deposited so as to fill a trench near an end of the elastic support 66.

The shell 103 has a support structure 68 disposed so as to penetrate through holes 100 provided in the mass 72.
Is supported on the substrate. The support structure 68 includes an SOI layer portion 80 formed by trench etching and a metal portion 73 penetrating through the Si nitride film layer 70 of the shell, which is fixed on a base substrate 78 by a Si nitride layer 77, The electrode also serves as an electrode for detecting the displacement of the mass 72 in the y-axis direction. On the side surface of this SOI layer portion 80, as shown in FIG. 22, a high concentration diffusion layer 85 is formed only on one side surface. The distance between the vibration system formed of polycrystalline Si buried in the trench and the side wall of the SOI layer is large on the side where the high-concentration diffusion layer 85 is located and small on the side where the high-concentration diffusion layer 85 is not located. It should be noted that the side surfaces of the support structure 68 where the high concentration diffusion layer 85 is formed are opposite every other as shown in the figure.

FIG. 23 shows the fixed portion of the shell along the elastic support 66 on the surface of the SOI substrate.
As shown in (a) and (c), a tunnel portion 81 used as an etching hole is formed, and is sealed with a metal 74. Further, the support structure 68 is formed by the metal portion 73 in FIG.
As shown in (b), they are electrically connected to each other, and are grouped at every other connection point a and b. The details of the connection are not shown. The mass 72 is also electrically connected to the SOI layer 76 via the fixing portion 65 (connection point c), and is further electrically connected to the metal portion 74. Further, the polycrystalline Si film 71 forming the shell 103 is also electrically connected (connection point c) by the metal part 74. Therefore, the mass 72 and the polycrystalline Si film 71 forming the shell 103 are electrically connected to each other.

In this embodiment, one through hole 1
One support structure 68 is provided in 00. However, the distance between the mass 72 deposited in the trench and the support structure 68 formed of the SOI layer differs depending on the presence or absence of the high-concentration diffusion layer 85 on the trench side wall, and every other support structure 68 is provided. Since the connection point a and the connection point b are combined, a differential capacitance circuit is formed by the mass 72 and the support structure 68 as shown in FIG. The displacement in the y-axis direction can be detected.
The signal from the differential capacitance circuit is connected to a signal processing circuit (not shown) via the metal part 73 and the metal part 74.

Next, a method of manufacturing the embodiment shown in FIGS. 22 and 23 will be described. 24 and 25 are schematic cross-sectional views taken along the line HH 'showing the manufacturing process of the embodiment shown in FIG. It should be noted that steps (a) to (f) of FIGS.
(I) shows a series of steps, which are shown in two figures for convenience of illustration. 26 is a schematic sectional view taken along the line II ′, FIG. 27 is a schematic sectional view taken along the line JJ ′, and FIG.
It is a cross section schematic diagram.

The steps will be described below in the order of steps with reference to FIGS. FIG. 24A uses an SOI substrate that is an oxide film layer and a Si nitride film layer on which a dielectric isolation layer is patterned. FIG. 28A After oxidizing the SOI substrate to form an oxide film 75, a Si nitride film 69 is formed. 24B, the oxide film 75 and the Si nitride film 69 are patterned into a first trench pattern, and a trench is formed in the SOI layer up to the dielectric isolation layer. Thereafter, the surface of the SOI substrate is protected by an oxide film 75 and a Si nitride film 69, and a high concentration diffusion layer 85 is formed on the side wall in the trench. FIG. 24 (c) The surface of the SOI substrate has an oxide film 75 and Si nitride
Protected by a film 69 and oxidizing the trench side walls to form an oxide film 83.

FIG. 24D: Polycrystalline Si is deposited in the formed trench, and the surface of the SOI substrate is flattened. 24 (e), 26 (a) and 27 (a) Oxide film 7
5 and the Si nitride film 69 are patterned into a second trench pattern, and a trench is formed in the SOI layer up to the dielectric isolation layer. Then, the surface of the SOI substrate is covered with an oxide film 75 and nitrided S
Protected by i-film 69 and oxidized trench sidewalls to form oxide film 84
To form Since the impurity concentration on the side wall surface is different, the oxidation rate is different from that of the first trench side wall, so that the oxide film 83 and the oxide film 84 have different film thicknesses. Polycrystalline Si is deposited in the formed trench to flatten the surface of the SOI substrate.

FIGS. 26 (b) and 27 (b) A mask layer 86 having an opening is formed in the region where the fixed portion 65 of the elastic support 66 is formed, and the oxide film 84 is removed. FIG. 26C, FIG. 27C Polycrystalline Si forming the fixed portion 65 is deposited in the groove formed by the removed oxide film, and planarization is performed. FIG. 25F: After removing the Si nitride film in the region where the vibration system is to be formed and depositing the oxide film 87, patterning is performed in accordance with the shape of the closed space to be formed. FIG. 25G A polycrystalline Si film 71 constituting a shell is deposited and patterned.

FIG. 28 (b) Shell polycrystalline Si film 71
Is patterned in accordance with the support structure 68, and a Si nitride film 70 is further deposited on the entire surface, and the Si nitride film 70 is patterned in accordance with the metal part 73 forming the support structure 68 to form an etching hole. FIGS. 25 (h), 27 (d), and 28 (c) The oxide films 83, 84 and 87 are removed using a hydrofluoric acid-based solution, and a closed space, a mass 72 and an elastic support 67 are provided in the shell. To form a vibration system. When the oxide films 83, 84, 87 are removed, the space around the shell support structure 68 that penetrates the mass 72 also functions as an etching hole.

FIGS. 25 (i), 26 (d), 28
(D) A metal is deposited on the entire surface and patterned. Through the above steps, the acceleration sensor shown in FIG. 22 is formed.

With the configuration described above, the present embodiment has the following advantages as compared with the fourth embodiment. (1) Since the vibration system is formed of polycrystalline Si deposited in the trench of the SOI layer, the thickness of the vibration system structural material can be increased without increasing the step on the substrate surface. Therefore, the capacitance value increases with an increase in the electrode facing area, and the S
/ N can be detected at a high level. (2) Since the cross section of the structure formed of polycrystalline Si deposited in the trench of the SOI layer has a closed shell structure, the rigidity can be improved more than the cross sectional area. (3) By using a configuration similar to that of the sixth embodiment, it is possible to realize an angular velocity sensor by a manufacturing process similar to that of the sixth embodiment.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention,
(A) is a schematic plan view, (b) is an LL ′ cross-sectional schematic view of (a), and (c) is a MM ′ cross-sectional schematic view of (a).

FIG. 2 is a circuit diagram showing an example of a differential capacitance circuit using the physical quantity sensor of FIG.

FIG. 3 is a schematic cross-sectional view showing a part of a manufacturing process according to the embodiment of FIG. 1;

FIG. 4 is a schematic sectional view showing another part of the manufacturing process of the embodiment of FIG. 1;

FIG. 5 is a diagram showing a second embodiment of the present invention;
(A) is a schematic plan view, (b) is an NN 'cross-sectional schematic view of (a), and (c) is an OO' cross-sectional schematic view of (a).

FIG. 6 is a schematic cross-sectional view showing a part of the manufacturing process according to the embodiment of FIG. 5;

FIG. 7 is a schematic sectional view showing another part of the manufacturing process of the embodiment in FIG. 5;

FIG. 8 is a diagram showing a third embodiment of the present invention;
(A) is a schematic plan view, and (b) is a schematic cross-sectional view taken along the line PP ′ of (a).

9 is a schematic cross-sectional view showing a part of the manufacturing process of the embodiment in FIG.

FIG. 10 is a schematic sectional view showing another part of the manufacturing process of the embodiment in FIG. 8;

FIG. 11 is a diagram showing a fourth embodiment of the present invention;
(A) is a schematic plan view, (b) is an AA ′ cross-sectional schematic view of (a), and (c) is a BB ′ cross-sectional schematic view of (a).

FIG. 12 is a schematic sectional view showing a part of the manufacturing process of the embodiment in FIG. 11;

FIG. 13 is a schematic cross-sectional view showing another part of the manufacturing process of the embodiment in FIG. 11;

FIG. 14 is a diagram showing a fifth embodiment of the present invention;
(A) is a schematic plan view, (b) is a CC ′ cross-sectional schematic view of (a), and (c) is a DD ′ cross-sectional schematic view of (a).

FIG. 15 is a schematic sectional view showing a part of the manufacturing process according to the embodiment of FIG. 14;

FIG. 16 is a schematic sectional view showing another part of the manufacturing process according to the embodiment in FIG. 14;

FIG. 17 is a diagram showing a sixth embodiment of the present invention;
(A) is a schematic plan view, (b) is an EE 'cross-sectional schematic view of (a).

FIG. 18 is a schematic cross-sectional view showing the manufacturing process of the embodiment in FIG.

FIG. 19 is a diagram showing a seventh embodiment of the present invention;
(A) is a schematic plan view, (b) is an FF ′ cross-sectional schematic view of (a), and (c) is a GG ′ cross-sectional schematic view of (a).

FIG. 20 is a schematic sectional view showing a part of the manufacturing process according to the embodiment in FIG. 19;

FIG. 21 is a schematic sectional view showing another part of the manufacturing process according to the embodiment in FIG. 19;

FIGS. 22A and 22B are views showing a part of the eighth embodiment of the present invention, wherein FIG. 22A is a schematic plan view, and FIG. 22B is HH ′ of FIG.
FIG.

FIGS. 23A and 23B are views showing another part of the eighth embodiment of the present invention, wherein FIG. 23A is a schematic sectional view taken along the line II ′ of FIG. 22A, and FIG. ) JJ ′ cross-sectional schematic view,
FIG. 22C is a schematic cross-sectional view taken along the line KK ′ of FIG.

FIG. 24 is a schematic cross-sectional view showing a part of the manufacturing process according to the embodiment shown in FIGS. 22 and 23;

FIG. 25 is a schematic sectional view showing another part of the manufacturing process in the embodiment of FIGS. 22 and 23;

FIG. 26 is a schematic sectional view showing another part of the manufacturing process in the embodiment of FIGS. 22 and 23;

FIG. 27 is a schematic sectional view showing another part of the manufacturing process according to the embodiment shown in FIGS. 22 and 23;

FIG. 28 is a schematic sectional view showing another part of the manufacturing process in the embodiment of FIGS. 22 and 23;

FIG. 29 is a circuit diagram showing an example of a circuit for driving mass and detecting a Coriolis force by four electrodes facing the potential of mass.

FIG. 30 is a schematic plan view of a first conventional example.

FIG. 31 is a schematic plan view showing an example of a defect that occurs in the first conventional example.

FIGS. 32A and 32B are views showing a second conventional example, in which FIG. 32A is a schematic plan view, and FIG. 32B is a schematic sectional view taken along line QQ ′ of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Inertia mass 2 ... Beam part 3, 4, 5 ... Comb electrode 6 ... Detection electrode 7 ... Vibration mass 8, 9 ... Support part 10 ... Comb electrode 11 ... Oxide film 12 ... Substrate 13 ... Detection electrode 15 ... Mass DESCRIPTION OF SYMBOLS 16 ... Support structure 17 ... Elastic support 18 ... Fixed part 19 ... Support structure 20 ... Polycrystalline Si film 21 ... Si nitride film 22 ... Metal part 23 ... Metal part 24 ... Si nitride film 25 ... Si oxide film 26 ... Si substrate 27 ... Fixed part 28 ... Elastic support 29 ... Support structure 30 ... Mass 32 ... Support structure 33 ... Electrode 34 ... Si nitride film 35 ... Polycrystalline Si film 36 ... Si nitride film 37 ... Si nitride film 38 ... Si oxide film 39 ... Si substrate 40 ... polycrystalline Si wiring 41 ... metal part 42 ... electrode 44 ... polycrystalline Si part 45 ... oxide film 46 ... polycrystalline Si part 47 ... oxide film 48 ... mass 49 ... support structure 50 ... Elastic support 51 ... fixed part 5 ... Supporting structure 53 ... Si nitride film 54 ... Polycrystalline Si film 55 ... SOI layer portion 56, 57 ... Metal portion 58 ... Si oxide film 59 ... SOI layer 60 ... Si nitride film 61 ... Base substrate 62 ... SOI substrate 63 ... Si nitride film 64 ... oxide film 65 ... fixed part 66 ... elastic support 67 ... trench part 68 ... support structure 69 ... Si nitride film 70 ... Si nitride film 71 ... polycrystalline Si film 72 ... mass 73,74 ... metal part 75 ... Si oxide film 76 ... SOI layer 77 ... Si nitride layer 78 ... Base substrate 79 ... SOI substrate 80 ... SOI layer part 81 ... Tunnel part 82 ... Trench 83 ... Oxide film 84 ... Oxide film 85 ... High concentration diffusion layer 86 ... Mask layer 87 ... Oxide films 88, 89 ... Displacement limiting means 90 ... Polycrystalline Si part 91, 92 ... Displacement limiting means 93 ... Polycrystalline Si part 100 ... Through hole 101 ... Through hole 102 ... Si Le 103 ... shell 159 ... driving power source OS
C1 160: detection power supply OSC2 162: demodulator 163: buffer

Claims (26)

[Claims] A vibration system having a mass formed of a conductive material and an elastic support formed of a conductive material for supporting the mass on a substrate; a vibration system fixed to the substrate and provided in the mass. Displacement limiting means disposed to penetrate through the through-hole, and limiting the displacement of the mass, and the mass detecting a force generated in the mass in response to a dynamic quantity input as a displacement of the mass in a detection axis direction. And an electrode which is electrostatically coupled. 2. The physical quantity sensor according to claim 1, wherein the displacement limiting means also serves as an electrode for detecting a displacement of the mass in a detection axis direction. 3. The method according to claim 1, wherein at least one of the vibration system formed of the conductive material, the displacement limiting means, and the electrode for detecting the displacement of the mass in the detection axis direction is formed of a deposited conductive material. The physical quantity sensor according to claim 1 or 2, wherein 4. The method according to claim 1, wherein at least one of the vibration system formed of the conductive material, the displacement limiting means, and the electrode for detecting the displacement of the mass in the detection axis direction is formed of a single-crystal conductive material. The physical quantity sensor according to claim 1 or 2, wherein: 5. A vibration system having a mass formed of a conductive material and an elastic support formed of a conductive material for supporting the mass on a substrate; and a vibration system fixed to the substrate and provided in the mass. Displacement limiting means disposed to penetrate through the through-hole, and limiting the displacement of the mass, and the mass detecting a force generated in the mass in response to a dynamic quantity input as a displacement of the mass in a detection axis direction. A first electrode electrostatically coupled to the mass, and a second electrode electrostatically coupled to the mass for driving the mass in a direction different from the displacement detection axis direction of the mass. Quantity sensor. 6. The dynamics according to claim 5, wherein said displacement limiting means also serves as a first electrode for detecting a displacement of said mass in a detection axis direction or a second electrode for driving said mass. Quantity sensor. 7. A vibration system formed of the conductive material, at least one of the displacement limiting means, a first electrode for detecting displacement of the mass in a detection axis direction, and a second electrode for driving the mass. 7. The physical quantity sensor according to claim 5, wherein one of the physical quantity sensors is formed of a deposited conductive material. 8. A vibration system formed of the conductive material, at least one of the displacement limiting means, a first electrode for detecting a displacement of the mass in a detection axis direction, and a second electrode for driving the mass. 7. The physical quantity sensor according to claim 5, wherein one of the physical quantity sensors is formed of a single-crystal conductive substance. 9. The displacement limiting means has a sufficient height above the substrate such that the mass cannot be displaced beyond the displacement limiting means in an allowable input range. The physical quantity sensor according to claim 1. 10. The displacement limiting means, wherein the size of the portion of the mass protruding from the through hole at the end opposite to the substrate fixed end is larger than the inner diameter of the through hole, and 10. The physical quantity sensor according to claim 1, wherein the physical quantity sensor has a shape that limits displacement. 11. A displacement limiting means having a plurality of said displacement limiting means, said displacement limiting means being connected to at least one adjacent another said displacement limiting means at an end opposite to a substrate fixed end so as to surround said mass. The physical quantity sensor according to claim 1, wherein the physical quantity sensor has a shape that limits displacement of the mass in a direction normal to the substrate. 12. A vibration system having a mass formed of a conductive material and an elastic support, and a support structure fixed to the substrate and arranged to pass through a through hole provided in the mass. And a conductive shell supported on the substrate by the support structure and forming a closed space including the vibration system with the substrate; and detecting a force generated in the mass in response to a mechanical quantity input in a detection axis direction. A dynamic quantity sensor comprising: an electrode that is electrostatically coupled to the mass to be detected as the displacement of the mass; and a displacement limiting unit that limits the displacement of the mass. 13. The dynamic quantity according to claim 12, wherein the support structure of the shell also serves as at least one of an electrode for detecting displacement of the mass in a detection axis direction and a displacement limiting means for the mass. Sensor. 14. A method according to claim 1, wherein said shell also serves as said mass displacement limiting means, or said shell is composed of a plurality of electrically independent regions, and also serves as an electrode for detecting displacement of said mass in the detection axis direction. The physical quantity sensor according to claim 12 or 13, wherein: 15. A conductive system, a supporting structure supporting the shell, a vibration system formed of the conductive material,
15. The device according to claim 12, wherein at least one of the electrode for detecting the displacement of the mass in the detection axis direction and the displacement limiting means for the mass is formed of a deposited conductive material. Dynamic quantity sensor. 16. The conductive shell, a support structure supporting the shell, a vibration system formed of the conductive material,
15. The electrode according to claim 12, wherein at least one of the electrode for detecting the displacement of the mass in the detection axis direction and the displacement limiting means for the mass is formed of a single-crystal conductive material. The physical quantity sensor as described. 17. The physical quantity sensor according to claim 1, wherein the input physical quantity is an acceleration. 18. A vibrating system having a mass formed of a conductive material and an elastic support, and a support structure fixed to the substrate and arranged to pass through a through hole provided in the mass. And a conductive shell supported on the substrate by the support structure and forming a closed space including the vibration system with the substrate; and detecting a force generated in the mass in response to a mechanical quantity input in a detection axis direction. A first electrode electrostatically coupled to the mass to be detected as the displacement of the mass, and a second electrode electrostatically coupled to the mass to drive the mass in a direction different from the direction of the mass displacement detection axis. And a means for limiting displacement of the mass. 19. The physical quantity sensor according to claim 18, wherein the closed space is maintained at a vacuum. 20. The shell support structure includes at least one of a first electrode for detecting displacement of the mass in a detection axis direction or a second electrode for driving the mass, and a displacement limiting means for the mass. The physical quantity sensor according to claim 18, wherein the physical quantity sensor also serves as 21. The shell also serves as the displacement limiting means for the mass, or the shell is formed of a plurality of electrically independent regions, and the first electrode or the first electrode for detecting the displacement of the mass in the detection axis direction. 21. The physical quantity sensor according to claim 18, wherein the physical quantity sensor also serves as a second electrode for driving a mass. 22. The conductive shell, a support structure supporting the shell, a vibration system formed of the conductive material,
At least one of the first electrode for detecting the displacement of the mass in the detection axis direction, the second electrode for driving the mass, and the displacement limiting means for the mass is formed of a deposited conductive material. The physical quantity sensor according to any one of claims 18 to 21. 23. The conductive shell, a support structure supporting the shell, a vibration system formed of the conductive material,
At least one of the first electrode for detecting the displacement of the mass in the detection axis direction, the second electrode for driving the mass, and the displacement limiting means for the mass is formed of a single-crystal conductive material. The physical quantity sensor according to any one of claims 18 to 21. 24. The physical quantity to be input is an angular velocity.
The physical quantity sensor according to claim 23. 25. A vibration system formed of the conductive substance,
23. The physical quantity sensor according to claim 3, wherein the physical quantity sensor is formed of a conductive substance deposited in a groove provided on the substrate. 26. An integrated circuit, wherein the physical quantity sensor according to claim 12 and a peripheral signal processing circuit are integrated in a semiconductor chip, and the semiconductor chip is molded with a resin.