JP2006349563A - Inertial force sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems, wherein changes in stress in a frame 1, following a temperature change, are transferred to a sensor circuit and the impedance is changed by a large amount, since wirings 7 that connect an electrode pad 6 in a conventional inertial force sensor and a sensor circuit are embedded into the frame 1 for penetration, and are connected to a fixed electrode 5 and an anchor 2 inside a sensor for constituting the sensor circuit by fixed wiring. <P>SOLUTION: The wiring 7 is provided at a spring-like part 7S as aerial wiring, change in pressure generated in the frame 1 following the temperature change is absorbed by the spring-like part 7S, and thus impedance change in the sensor circuit with respect to the temperature change is inhibited. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a capacitance-type inertial force sensor that measures acceleration, angular velocity, and the like.

  The main structure of the capacitance-type inertial force sensor is that the fixed electrode fixed between the upper surface substrate and the lower surface substrate and the beam that is an elastic body provided on the anchor that is a support fixed to any one of the substrates are supported in the air. The movable electrode, which is the inertial body, and the wiring for connecting the fixed electrode and the movable electrode to an external circuit. The inertial force applied to the inertial force sensor is obtained by measuring the capacitance between the movable electrode and the fixed electrode at a position where the inertial force applied to the movable electrode and the restoring force of the beam having elastic characteristics are balanced. Since the conventional inertial force sensor measures the electrostatic capacitance between the fixed electrode and the movable electrode with an external circuit, the fixed electrode or anchor (electrically connected to the movable electrode) is interposed between the upper surface substrate and the lower surface substrate. In other words, the polysilicon wiring is connected to an electrode pad provided outside (see, for example, Patent Document 1).

Japanese Patent Application No. 2002-40039 (paragraphs 0009-0010, FIG. 2)

  The polysilicon wiring of the conventional inertial force sensor is embedded in the frame part that supports the lower surface substrate and the upper surface substrate from the electrode pad, penetrates into the inertial force sensor, and is fixed from the inner end surface of the frame part. Therefore, the stress change in the frame portion due to the temperature change is transmitted to the anchor through the fixed wiring, and as a result, the static electrode between the movable electrode supported by the anchor and the fixed electrode is transferred. There was a problem that the capacitance (impedance) changed greatly.

  In the inertial force sensor of the present invention, the upper surface substrate and the lower surface substrate face each other, and the fixed electrode and the anchor column fixed to the upper surface substrate or the lower surface substrate, the elastic beam supported by the anchor column, and advanceable and retreatable to the elastic beam A movable electrode supported in the air, and a wiring having a spring-like aerial wiring portion for electrically connecting the movable electrode or the fixed electrode and an external circuit between the upper surface substrate and the lower surface substrate are provided. In addition, the inertial force is detected based on a change in electrostatic capacitance between the movable electrode that moves forward and backward depending on the inertial force of the movable electrode and the fixed electrode.

  According to the inertial force sensor of the present invention configured as described above, the wiring portion extending from the inner end face of the frame portion to the anchor or the fixed electrode is a spring-like aerial wiring portion. The change is absorbed by the spring-like part of the aerial wiring, and the stress of the frame part is difficult to be transmitted to the anchor and the fixed electrode. As a result, the temperature change of the capacitance (impedance) between the movable electrode and the fixed electrode The effect that the fluctuation | variation accompanying this can be eased is acquired.

Embodiment 1 FIG.
The first embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a plan view showing a schematic configuration of an inertial force sensor according to an embodiment of the present invention. 2 is a cross-sectional view taken along the alternate long and short dash line in FIG. 1 and an enlarged cross-sectional view showing a portion thereof enlarged. FIG. 3 is a cross-sectional view taken along the alternate long and short dash line B in FIG. 4 is an enlarged cross-sectional view in which the portion is enlarged and FIG. 4 is a cross-sectional view taken along the one-dot chain line C in FIG. FIGS. 5 to 13 show the cross-sectional shapes of the inertial force sensor according to the present invention through the respective manufacturing processes up to the cross-sectional shape corresponding to the one-dot chain line AA shown in FIG. It is an expanded sectional view which expanded and displayed a part of the sectional view of the halfway process and the sectional view. 14 is a plan view and a cross-sectional view showing a schematic configuration of a conventional inertial force sensor for comparison with the inertial force sensor of Embodiment 1 of the present invention shown in FIG. 1 to 14, the same reference numerals are given to the same or corresponding parts. FIG. 15 is a graph showing the results of measuring the amount of change in impedance associated with the temperature change of the surrounding environment of the inertial force sensor of the present invention of FIG. 1 and the conventional inertial force sensor of FIG. The inertial force sensor of the present invention is a sensor that detects characteristics derived from inertial forces such as acceleration, angular velocity, and angular acceleration.

  As shown in FIG. 1, the arrangement of the main parts constituting the inertial force sensor of the present invention is as follows. The frame 1 is a conductor flat plate, for example, extracted by etching, etc. A movable electrode 4 supported in the air via a pair of elastic beams 3 supported by a pair of formed anchor pillars 2 and 16 fixed electrodes 5 are arranged, and an external circuit is provided on the outer portion 1 a of the frame 1. Three electrode pads 6 made of a conductor for connection to (not shown) are arranged. The anchor pillar 2 or each fixed electrode 5 is electrically connected to each electrode pad 6a, 6b, 6c by wiring 7a, 7b, 7c made of, for example, polysilicon which is a conductor wiring. In particular, the wiring 7 of the present invention has a spring-like aerial wiring portion 7s so that a part thereof has elastic characteristics. Here, the term “spring shape” as used herein refers to a shape that collectively refers to a structure that can absorb meandering deformation such as a U-shape and an S-shape. Further, the movable electrode 4 is provided with two sets of movable electrode groups 4a and 4b composed of five flat plate electrode groups, which are arranged so as to face the fixed electrodes 5, respectively. Capacitance is formed between the two. The 16 fixed electrodes 5 are electrically connected by polysilicon wiring 7a or 7b to form two sets of fixed electrode groups 5a and 5b of 8 pieces each. Note that the number of plate electrode groups provided on the movable electrode 4, the number of fixed electrodes 5, the number of electrode pads 6, and the like can be changed, and the number described here is not limited.

  Further, as shown in the cross-sectional view of FIG. 2, the inertial force sensor of the present invention fixes the frame 1 on the first glass substrate 8, which is a bottom substrate having substantially the same external dimensions as the frame 1, and further A cavity is provided inside the frame 1 because the second glass substrate 9, which is a top substrate having a slightly smaller outer dimension, is fixed on the top via various insulating films and the like. In this cavity, the movable electrode 4 is supported in the air via a pair of elastic beams 3 supported by the anchor column 2 fixed to the second glass substrate 9 and is fixed to the second glass substrate 9. Further, 16 fixed electrodes 5 (see FIGS. 1 and 4) and a wiring 7c having a spring-like aerial wiring portion 7sc are arranged. The anchor pillar 2 and the 16 fixed electrodes 5 that support the movable electrode 4 and the elastic beam 3 in the air are positioned by being fixed to a second glass substrate 9 that is a top substrate.

  Next, electrode pads 6c, wirings 7c, various insulating films, and a top substrate fixed on the frame 1 extracted from the silicon wafer using the enlarged cross-sectional views of FIGS. 2B and 3B. The arrangement structure of the second glass substrate 9 will be described. A specific manufacturing process of the inertial force sensor of the present invention will be described in detail later. As shown in FIG. 2B, a first insulating film 11, a second insulating film 12, a third insulating film 13, a fourth insulating film 14, and a fifth insulating film 15 are formed on the frame 1, An electrode pad 6c is formed thereon, or the second glass substrate 9 is fixed together with the formation of the polysilicon film 16. Incidentally, a part of the third insulating film 13 is replaced with a polysilicon wiring 7c as shown in FIG. 3B, and this wiring 7c is further replaced by an electrode pad as shown in FIG. 2B. 6c is connected to the electrode pad 6c through a through hole provided in the fourth insulating film 14 and the fifth insulating film 15 below.

  Next, an arrangement structure of the fixed electrode group 5b, the polysilicon wirings 7a and 7b, and various insulating films will be described with reference to the enlarged sectional view of FIG. A specific manufacturing process of the inertial force sensor of the present invention will be described in detail later. As shown in FIG. 4B, on the fixed electrode group 5b, the first insulating film 11, the second insulating film 12, the third insulating film 13, the fourth insulating film 14, the fifth insulating film 15, and polysilicon are formed. A film 16 is formed, and the second glass substrate 9 is fixed thereon. The polysilicon wirings 7 a and 7 b are replaced by being embedded in a part of the third insulating film 13. The polysilicon wiring 7 b is connected to the fixed electrode group 5 b through through holes provided in the first insulating film 11 and the second insulating film 12. The polysilicon wiring 7b is not electrically connected to the fixed electrode group 5a. In addition, although not shown, it is connected to the fixed electrode group 5 a through a through hole provided in the first insulating film 11 and the second insulating film 12. The polysilicon wiring 7a is not connected to the fixed electrode group 5b.

  The operation of the inertial force sensor of the present invention will be described below. For example, when acceleration is applied in the left-right direction in FIG. 1, inertial force depending on acceleration is applied to the movable electrode 4, and the position of the movable electrode 4 moves to a position that balances with the restoring force of the elastic beam 3 having elastic characteristics. The relative position with respect to the fixed electrode 5 changes. The movable electrode groups 4a to 4b, which are plate electrode groups provided on the movable electrode 4, are arranged in a relationship facing each other with the fixed electrode group 5a or the fixed electrode group 5b. Form. As the relative position of the movable electrode 4 and the fixed electrode groups 5a and 6b moves, the capacitance changes differentially, so that at least one of the movable electrode 4 and the fixed electrode group 5a or 6b is at least one of them. Since the change in capacitance is measured, the inertial force and acceleration applied to the movable electrode 4 can be detected. Note that the change in capacitance between the movable electrode 4 (movable electrode groups 4a and 4b) and the fixed electrode groups 5a and 6b varies between the electrode pads 6c and 6a or 6c and 6b electrically connected to each other. Such an impedance can be measured by an external circuit (not shown). Therefore, it is clear that the inertial force applied to the inertial force sensor according to the first embodiment of the present invention can be detected from the impedance measurement between the electrode pads 6 provided in the inertial force sensor.

  The manufacturing process of the inertial force sensor of the present invention will be described with reference to FIGS. FIG. 5A to FIG. 13A are cross-sectional views of the intermediate process showing the cross-sectional shape of the intermediate process that changes with each manufacturing process with respect to the portion corresponding to the cross section cut along the alternate long and short dash line A in FIG. FIG. FIGS. 5 to 13B are enlarged cross-sectional views of a portion surrounded by a two-dot chain line in the corresponding drawing number (a).

  FIG. 5 shows a state in which a first insulating film 11 such as a silicon oxide film and a second insulating film 12 such as a silicon nitride film are deposited on the silicon wafer 10 by a film forming apparatus. However, various main parts (frame 1, anchor pillar 2, fixed electrode 5, etc.) extracted from the polysilicon wiring 7 and the silicon wafer 10 and parts to be electrically connected are previously used with a masking material or the like. The opening portion is patterned, and then unnecessary portions of the second insulating film 12 are removed by etching. The first insulating film 11 serves as an etching stopper layer in the through etching process for extracting various main parts from the silicon wafer 10 to be performed in a later process, and prevents the etching of unnecessary portions.

  FIG. 6 shows a state in which the polysilicon wiring 7 is deposited by patterning with a film forming apparatus. Note that it is desirable that the polysilicon wiring 7 in this portion is mixed with an impurity such as boron to form a thin film having a low electrical resistance.

  FIG. 7 shows a state in which a third insulating film 13 such as a silicon oxide film is pattern-deposited. The third insulating film 13 is formed so as to bury the previously formed polysilicon wiring 7 and has a role of filling the step.

  FIG. 8 shows a state in which a fourth insulating film 14 such as a silicon oxide film and a fifth insulating film 15 such as a silicon nitride film are deposited. However, the opening portion of the portion to be electrically connected to the polysilicon wiring 7 and the bonding polysilicon film 16 is patterned and opened with a masking material or the like.

  FIG. 9 shows a state in which a polysilicon film 16 to be bonded to the second glass substrate 9 is patterned and deposited. The surface of the polysilicon film 16 is buried by the third insulating film 13 with respect to the polysilicon wiring 7 to eliminate the stepped portion, and the surface roughness may be reduced to 500 mm or less by heat treatment, mechanical polishing, chemical polishing or the like. It is desirable for improving the adhesion with the second glass substrate 9. The polysilicon film 16 is preferably non-doped polysilicon that does not contain impurities such as boron. This is based on the fact that the polysilicon film 16 is non-doped polysilicon, so that sufficient adhesion to the second glass substrate 9 can be ensured even by an anodic bonding method at a relatively low temperature.

  In other words, the potential on the second glass substrate 9 side with respect to the polysilicon film 16 is set to a negative bias of 400 to 1500 V, the polysilicon film 16 is adhered to the second glass substrate 9, and the temperature is raised to 300 to 500 ° C. In the case of holding for 2 to 5 hours, unless the impurity concentration in the polysilicon film 16 is 100 ppb or less (except for oxygen and carbon), sufficient adhesion strength cannot be obtained, and the polysilicon film 16 and the second film This is because the glass substrate 9 cannot be bonded. Based on this knowledge, in the inertial force sensor according to the first embodiment of the present invention, since the polysilicon film 16 used is non-doped polysilicon, it is possible to achieve high mechanical reliability. Is obtained.

  FIG. 10 shows a state in which electrode pads 6 that are electrically connected to an external circuit by wire bonding are formed by a plating technique such as sputtering or plating using aluminum or gold.

  FIG. 11 shows a state in which the second glass substrate 9 is anodically bonded to the polysilicon film 16. The second glass substrate 9 has a structure in which holes are formed in advance on the electrode pads 6 so that wire bonding can be performed. After the second glass substrate 9 is bonded, the silicon wafer 10 is processed to a desired thickness, for example, about several tens of μm to one hundred μm, by lapping polishing using mechanical polishing or chemical polishing.

  FIG. 12 shows a state where the anchor pillar 2, the elastic beam 3, the movable electrode 4, the fixed electrode 5, the frame 1 and the like are formed by etching the silicon wafer 10 so as to penetrate through the back surface by dry etching or the like. The first insulating film 11 functions as an etching stop layer. That is, the first insulating film 11 prevents damage to the polysilicon wiring 7 and the polysilicon film 16, which are portions that are not desired to be etched during the dry etching.

  FIG. 13 shows a state where the first insulating film 11 is selectively removed with hydrofluoric acid or the like and then anodic bonded to the first glass substrate 8 so that the sensor detection unit has a sealed structure. In addition, a groove is formed in advance in the first glass substrate 8 below a movable region where the movable electrode 4 or the like as a sensor detection unit is provided so as not to hinder the movement. The inertial force sensor of the present invention is completed by the manufacturing process described above.

  According to the first embodiment of the present invention, a spring-like aerial wiring portion 7sc is provided between the frame 1 and the anchor pillar 2 so that a part of the polysilicon wiring 7 has elastic characteristics, and the frame 1 and the fixed electrode. By newly providing 7sa or 7sb between the parts 6a or 6b, the influence of the frame part 10 that causes distortion of the bonding interface due to temperature change can be absorbed by the spring-like aerial wiring part 7sc. That is, since the polysilicon wiring 7 is difficult to transmit the strain generated in the frame portion 10 to the anchor pillar 2 and the fixed electrode 5, a special effect that an inertial force sensor with high temperature stability can be realized.

  Hereinafter, since the inertial force sensor of the present invention having the spring-like aerial wiring portion and the conventional inertial force sensor having the spring-like aerial wiring portion will be compared, a more specific effect of the present invention will be described. FIG. 14 is a plan view and a cross-sectional view of a conventional inertial force sensor having no spring-like aerial wiring for comparison with the inertial force sensor according to Embodiment 1 of the present invention shown in FIG. As can be seen from a comparison with FIG. 1 and FIG. 2 (a) showing the inertial force sensor of the present invention, the structure of the conventional inertial force sensor does not include a spring-like aerial wiring portion in the wiring, and uses a fixed wiring. Except for this, it has the same structure (configuration) as the inertial force sensor of the present invention shown in FIG.

  FIG. 15 shows the results of measuring the amount of change in impedance applied between the electrode pads 6c and 6a due to the temperature change by an external circuit (not shown) in the inertial force sensor of the present invention and the inertial force sensor of the comparative example. The amount of change in the impedance between the electrodes accompanying the temperature change of the inertial force sensor (spring-like aerial wiring) of the present invention is reduced to about ¼ compared with the conventional inertial force sensor (fixed wiring). . A part of the wiring provided between the frame 1 and the anchor column 2 or the fixed electrode 5 is spring-like aerial wiring, so that the influence of the distortion of the frame 1 caused by the temperature change is affected by the anchor column 2 and the fixed electrode 5. As a result, the position of the movable electrode 4 supported by the anchor column 2 in the air and the position of the fixed electrode 5 are less likely to change, and it is considered that the amount of change in impedance is reduced. Therefore, the configuration of the inertial force sensor according to the first embodiment of the present invention can provide an effect that a highly accurate sensor that does not easily change with respect to a temperature change can be realized.

  In addition, since the inertial force sensor frame 1 and the anchor column, the elastic beam, the movable electrode, and the fixed electrode are all formed by being extracted from the silicon wafer bonded to the second glass substrate 9, the frame 1 and the anchor column, the elastic beam, the movable electrode are movable. There is an effect that the relative positional relationship between the electrode and the fixed electrode is specified with high accuracy without being shaken during the manufacturing process and without being rearranged.

  Further, the movable electrode 4 supported in the air and the 16 fixed electrodes 5 and the like are sealed by the upper and lower substrates through a pair of elastic beams 3 supported by the pair of anchor pillars 2 extracted from the silicon wafer 10. Therefore, it is possible to realize an inertial force sensor that is highly resistant to disturbance and highly reliable. Furthermore, because of the sealed structure, expensive metal packages and ceramic packages are not required, and inexpensive plastic packages used for general semiconductor integrated circuit chips can be applied, and the inertial force sensor can be reduced in price. There is an effect that can be realized.

Embodiment 2. FIG.
Hereinafter, a second embodiment of the present invention will be described in detail with reference to the drawings. FIG. 16A is a plan view showing a schematic configuration of the inertial force sensor used in Embodiment 2 of the present invention. FIGS. 16B and 16C are enlarged cross-sectional views showing enlarged views of the respective cross sections when cut along the one-dot chain line AA or one-dot chain line BB shown in FIG. . In FIG. 16, the same or corresponding parts as those shown in FIGS. 1 to 14 are given the same reference numerals.

  A major difference between the inertial force sensor used in the second embodiment and the inertial force sensor used in the first embodiment is that the fixed electrode 5 is arranged inside the movable electrode 4. That is, the inertial force sensor used in the second embodiment has substantially the same configuration as that of the inertial force sensor used in the first embodiment, except for the parts described below. Hereinafter, the different parts will be described in detail. In FIG. 16A, the stationary electrode groups 5a and 6b of the inertial force sensor used in the second embodiment are arranged inside a gap provided inside the movable electrode 4. Each fixed electrode 5 is electrically connected by either polysilicon wiring 7a or 7b, and constitutes fixed electrode groups 5a and 6b. The wiring 7 a and the wiring 7 b are arranged so as to straddle the movable electrode groups 4 a and 4 b provided on the movable electrode 4. That is, as can be seen from FIGS. 16B and 16C, the polysilicon wirings 7a and 7b are arranged in the air via spaces so as not to contact the movable electrode groups 4a and 4b extracted from the silicon wafer 10. Has been. The above is the difference.

  In the inertial force sensor used in the second embodiment, since the movable electrode groups 4a and 4b provided on the movable electrode 4 have a structure in which the free ends are eliminated, the electrode groups 4a and 4b used in the first embodiment are combed. Different from the electrode structure with a tooth-like free end. Therefore, since the mechanical rigidity of the movable electrode 4 is increased, the structural deformation of the movable electrode 4 due to acceleration does not occur, and an effect that a highly reliable inertial force sensor can be realized.

Embodiment 3 FIG.
Hereinafter, a third embodiment of the present invention will be described in detail with reference to the drawings. FIG. 17A is a plan view showing a schematic configuration of the inertial force sensor used in Embodiment 3 of the present invention. FIG. 17B is a cross-sectional view taken along the alternate long and short dash line AA shown in FIG. In FIG. 17, the same or corresponding parts as those shown in FIGS. 1 to 14 and 16 are denoted by the same reference numerals.

  The major difference between the inertial force sensor used in Embodiment 3 and the inertial force sensor used in Embodiment 1 is that the movable electrode 4 is moved in a direction perpendicular to the paper surface. Details will be described below. In FIG. 16, the movable electrode 4 supported by the elastic beam 3 (different in shape from the first and second embodiments) supported in the air by the eight anchor pillars 2 is configured to be movable up and down with respect to the paper surface. Has been. Each anchor column 2 is positioned and fixed on the second glass substrate 9 via various insulating films. Metal fixed electrodes 17a and 17b are formed on the first glass substrate 8 and the glass second glass substrate 9 facing the movable electrode 4, respectively. The fixed electrodes 17a and 17b are electrically connected to the corresponding electrode posts 18a and 18b, and are further connected to the electrode pads 6a and 6b via the polysilicon wirings 7a and 7b. Except for the portions described above, the inertial force sensor used in the third embodiment has substantially the same configuration as the inertial force sensor used in the first embodiment.

  By adopting such a configuration, the inertial force sensor used in Embodiment 3 of the present invention is a small and thin inertial force that detects the inertial force in the vertical direction (out-of-plane direction) toward the paper surface with high accuracy. It is clear that it functions as a sensor.

FIG. 3 is a plan view of the inertial force sensor of the present invention in the first embodiment. Sectional drawing of the inertial force sensor of this invention in Embodiment 1. FIG. Sectional drawing of the inertial force sensor of this invention in Embodiment 1. FIG. Sectional drawing of the inertial force sensor of this invention in Embodiment 1. FIG. Sectional process sectional drawing of the inertial force sensor of this invention in Embodiment 1. FIG. Sectional process sectional drawing of the inertial force sensor of this invention in Embodiment 1. FIG. Sectional process sectional drawing of the inertial force sensor of this invention in Embodiment 1. FIG. Sectional process sectional drawing of the inertial force sensor of this invention in Embodiment 1. FIG. Sectional process sectional drawing of the inertial force sensor of this invention in Embodiment 1. FIG. Sectional process sectional drawing of the inertial force sensor of this invention in Embodiment 1. FIG. Sectional process sectional drawing of the inertial force sensor of this invention in Embodiment 1. FIG. Sectional process sectional drawing of the inertial force sensor of this invention in Embodiment 1. FIG. Sectional process sectional drawing of the inertial force sensor of this invention in Embodiment 1. FIG. FIG. 2 is a plan view and a cross-sectional view of a conventional inertial force sensor according to Embodiment 1. The result figure which measured about the variation | change_quantity of the impedance accompanying the temperature change of the inertial force sensor of this invention in Embodiment 1, and the conventional inertial force sensor. The top view and sectional drawing which show the inertial force sensor of this invention in Embodiment 2. FIG. FIG. 6 is a plan view and a cross-sectional view showing an inertial force sensor of the present invention in a third embodiment.

Explanation of symbols

2 Anchor pillar 3 Elastic beam 4 Movable electrode 6 Fixed electrode 7 Wiring 7S Spring-like aerial wiring section
8 First glass substrate (lower substrate) 9 Second glass substrate (upper substrate)
10 Silicon wafer (conductor plate)

Claims (5)

  The upper surface substrate and the lower surface substrate face each other, the fixed electrode and the anchor column fixed to the upper surface substrate or the lower surface substrate, the elastic beam supported by the anchor column, the movable electrode supported in the air so as to advance and retreat on the elastic beam, A movable wire that has a spring-like aerial wiring portion that electrically connects the movable electrode or the fixed electrode and an external circuit between the upper surface substrate and the lower surface substrate, and moves forward and backward depending on the inertial force of the movable electrode An inertial force sensor, wherein the inertial force is detected based on a change in capacitance between an electrode and the fixed electrode.   The upper surface substrate and the lower surface substrate face each other, the anchor column fixed to the upper surface substrate or the lower surface substrate, the elastic beam supported by the anchor column, the movable electrode supported in the air so as to advance and retreat on the elastic beam, the movable electrode A fixed electrode fixed to the upper surface substrate or the lower surface substrate, and the inertial force based on a change in capacitance between the movable electrode that moves forward and backward depending on the inertial force of the movable electrode and the fixed electrode. An inertial force sensor characterized by detecting the above.   3. An inertial force sensor according to claim 1, wherein the anchor column, the elastic beam, the movable electrode, and the fixed electrode of the inertial force sensor according to claim 1 are extracted from the same conductor flat plate.   4. The inertial force sensor according to claim 3, wherein the conductor flat plate of the inertial force sensor is a silicon wafer. 3. The upper surface substrate and the lower surface substrate of the inertial force sensor according to claim 1 or 2 are glass substrates, and a non-doped polysilicon film is an anodic bonding method on the surface of the upper surface substrate or the lower surface substrate facing each other. An inertial force sensor that is bonded with

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