JP2012083304A - Mems sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a MEMS sensor in which a plurality of wiring elements to be insulated from each other can cross while suppressing increase in manufacturing costs and further, physical quantity detection can be maintained excellent.SOLUTION: On a second inter-layer film 20 on a SOI substrate 2 with which a pair of X-detection elements Dare provided on a surface 21, inter-element wiring 43 is laid which connects these X-detection elements D. On the other hand, on the second inter-layer film 20, there are provided main wiring 36 of X-bridge wiring 31 and main wiring 36 of Z-detection upper electrode wiring 33 in a direction crossing the inter-element wiring 43. In order to avoid contact with the main wiring 36, relay wiring 45 is formed in the same layer as a lower electrode 25 of the X-detection element D, and the relay wiring 45 is utilized to detour a circuit composed of the inter-element wiring 43 to the inside of the second inter-layer film 20.

Description

  The present invention relates to a MEMS sensor.

MEMS (Micro Electro Mechanical Systems) sensors detect acceleration, angular velocity, pressure, and the like generated in an object by using a “structure” that changes due to the action of an external force.
For example, the motion sensor (1) disclosed in FIG. 1 of Patent Document 1 includes a frame-shaped support portion (S), and four beams (F) arranged in a cross shape inside the support portion (S). The columnar connecting part (C) connected to each of the four beams (F), the weight (M) connected to the connecting part (C), and the piezo provided on each of the four beams (F) A resistance element (131), a detection piezoelectric element (30b), a driving piezoelectric element (30a) that is provided on each of the four beams (F) and drives the weight (M) by bending the four beams (F); An insulating layer (40) laminated on the support portion (S) and the beam (F) so as to cover each piezoelectric element (30a, 30b), and each piezoelectric element formed on the insulating layer (40). And a surface wiring layer (50) connected to (30a, 30b).

JP 2010-145259 A

For example, in a MEMS sensor such as the motion sensor disclosed in Patent Document 1, capacitive elements such as piezoelectric elements may be connected by wiring. At that time, when the number of wirings is large with respect to a space where wirings can be laid, there is a place where a wiring that forms another circuit must be crossed when routing a wiring that forms a certain circuit.
In such a case, if a so-called multilayer wiring structure is adopted and the wiring forming one circuit is detoured to the upper wiring layer, the wirings can be crossed so as not to contact each other. In the motion sensor of Patent Document 1, for example, an insulating layer is further laminated on the insulating layer (40), and the surface wiring layer (50) connected to the driving piezoelectric element (30a) is bypassed on the insulating layer. If so, the surface wiring layer (50) connected to the driving piezoelectric element (30a) and the surface wiring layer (50) connected to the detection piezoelectric element (30b) can be crossed so as not to contact each other. It is done.

  However, steps such as a step of laminating an insulating layer and a step of forming a wiring for bypassing the insulating layer must be added, which increases the number of steps as a whole. With the increase in the number of steps, there is a problem that the manufacturing cost increases. In addition, when a multilayer wiring structure is formed on a movable part such as a beam (F) having a delicate structure, extra stress is applied to the delicate beam (F), which may adversely affect the detection of physical quantities.

  Accordingly, an object of the present invention is to provide a MEMS sensor capable of crossing a plurality of wirings to be insulated from each other while suppressing an increase in manufacturing cost and maintaining a good physical quantity detection. .

  The MEMS sensor according to claim 1 for achieving the above object includes a semiconductor substrate, a dielectric provided on the semiconductor substrate, and a lower electrode and an upper electrode facing each other with the dielectric interposed therebetween. A capacitive element, an insulating layer stacked on the semiconductor substrate and covering the capacitive element, a first wiring, and a second wiring separated on the insulating layer by the first wiring And a relay wiring that is formed in the same layer as the lower electrode or the upper electrode and extends across the first wiring along a horizontal direction along the surface of the lower electrode or the upper electrode in the layer And the second wiring divided on the insulating layer is electrically connected to each other through the relay wiring.

  According to this configuration, the second wirings separated on the insulating layer are electrically connected to each other via the relay wiring crossing the first wiring inside the insulating layer. Thereby, conduction of the second wiring can be achieved so as not to contact the first wiring. In addition, when forming the upper electrode or the lower electrode of the capacitive element, it is possible to simultaneously form a wiring (relay wiring) that forms a bypass of the second wiring. Therefore, an increase in the number of steps can be prevented, and an increase in manufacturing cost can be suppressed.

  Further, as described in claim 2, the semiconductor substrate may have a thin film portion that can be deformed by an external force and a frame that supports the thin film portion. In that case, the first wiring, the second wiring, and the relay wiring may be laid on the thin film portion. Even when the wiring is laid on the thin film portion, according to the configuration of the present invention, in order to form the base of the relay wiring crossing the first wiring, an insulating layer is further formed on the insulating layer serving as the base of the main wiring. There is no need to stack. For this reason, it is possible to suppress an excessive stress from being applied to the thin film portion.

According to a third aspect of the present invention, the capacitive element includes a first piezoelectric element and a second piezoelectric element, each of which is disposed on the thin film portion, and the dielectric is a piezoelectric body. The second wiring may include an inter-element wiring that electrically connects the first piezoelectric element and the second piezoelectric element, and a pad wiring that is electrically connected to the inter-element wiring.
In that case, as described in claim 4, the inter-element wiring may be divided by the first wiring on the insulating layer. In the configuration in which the inter-element wiring is divided, as described in claim 4, the relay wiring is formed in the same layer as the lower electrode of the first piezoelectric element and the lower electrode of the second piezoelectric element. A lower metal layer formed so as to cross the first wiring along the lateral direction, and a plug that connects the lower metal layer and each of the divided inter-element wirings. Furthermore, it is preferable to include.

  In this configuration, since the relay wiring is separated from both the lower electrodes of the first and second piezoelectric elements, the relay wiring is electrically connected from the electrodes (upper electrode and lower electrode) of the first and second piezoelectric elements. Can be electrically insulated. Therefore, the first piezoelectric element and the second piezoelectric element can be connected in series by appropriately setting the connection target on the side opposite to the connection side with the relay wiring in the inter-element wiring, or connected in parallel. You can also.

  For example, when the connection target of the divided one and other inter-element wiring is the same type of electrode (that is, when the connection target is the upper electrode of the first piezoelectric element and the upper electrode of the second piezoelectric element, or In the case of the lower electrode of the first piezoelectric element and the lower electrode of the second piezoelectric element), parallel connection of the first and second piezoelectric elements can be achieved. Further, when the connection target of the divided one and other inter-element wirings is a heterogeneous electrode (that is, when the connection target is the upper electrode of the first piezoelectric element and the lower electrode of the second piezoelectric element, or In the case of the lower electrode of the first piezoelectric element and the upper electrode of the second piezoelectric element), a series connection of the first and second piezoelectric elements can be achieved.

  Further, as described in claim 5, when the inter-element wiring is made of aluminum and the lower metal layer is made of platinum, the wiring constituting the circuit connecting the first piezoelectric element and the second piezoelectric element. The wiring (platinum wiring) whose electric conductivity is lower than that of aluminum can be secured to the lower metal layer. Therefore, even when the distance between the first piezoelectric element and the second piezoelectric element is long, if the inter-element wiring is used up to the vicinity of the first wiring, the average electrical conductivity between the first piezoelectric element and the second piezoelectric element. Can be suppressed. Note that the platinum wiring is not limited to a wiring made of only Pt, but is a concept including a wiring mainly containing Pt such as Pt / Ti.

The MEMS sensor may further include a dummy piezoelectric body formed on the lower metal layer and made of the same material as the piezoelectric bodies of the first piezoelectric element and the second piezoelectric element. May be included.
In this configuration, when the piezoelectric bodies of the first and second piezoelectric elements are formed by etching the piezoelectric material, the area where the dummy piezoelectric body is to be formed is masked in the same manner as the area where the piezoelectric body is to be formed in the piezoelectric material. Covered with. Thereby, during etching, the portion immediately below the dummy piezoelectric body in the lower metal layer (relay wiring) can be protected from an etching medium such as an etching gas. By this protection, damage to the lower metal layer can be suppressed and the thickness of the lower electrode layer can be maintained. As a result, an increase in internal resistance of the lower metal layer can be suppressed.

  When a dummy piezoelectric body is formed, the plug may penetrate the dummy piezoelectric body in a thickness direction and be connected to the lower metal layer as described in claim 7. Further, according to claim 8, if the lower metal layer is exposed from the dummy piezoelectric body, the plug is connected to the exposed portion of the lower metal layer while avoiding the dummy piezoelectric body. It may be.

  Further, when the second wiring includes a pad wiring and an inter-element wiring, the pad wiring and the inter-element wiring may be separated by the first wiring on the insulating layer. In the configuration in which the pad wiring and the inter-element wiring are divided, as described in claim 9, the relay wiring crosses the first wiring from the lower electrode of the first piezoelectric element. A first plug that connects the pad wiring and the upper electrode of the first piezoelectric element, and a second plug that connects the inter-element wiring and the electrode extraction part. It is preferable to further include a plug.

In this configuration, since the relay wiring and the lower electrode of the first piezoelectric element are integrally formed, the relay wiring and the lower electrode can be connected with a simple and reliable structure.
In addition, according to a tenth aspect of the present invention, the MEMS sensor further includes a piezoelectric lead portion that is integrally drawn along the surface of the electrode lead portion from the piezoelectric body of the first piezoelectric element. Also good.

  In this configuration, when the piezoelectric bodies of the first and second piezoelectric elements are formed by etching the piezoelectric material, the area where the piezoelectric lead portion is to be formed is also the same as the area where the piezoelectric body is to be formed in the piezoelectric material. Covered with a mask. Thereby, during etching, a portion immediately below the piezoelectric lead portion in the electrode lead portion (relay wiring) can be protected from an etching medium such as an etching gas. By this protection, damage to the electrode lead portion can be suppressed, and the thickness of the electrode lead portion can be maintained. As a result, an increase in internal resistance of the electrode lead portion can be suppressed.

  Further, when the piezoelectric lead portion is formed, the second plug is connected to the electrode lead portion through the piezoelectric lead portion in the thickness direction, as recited in claim 11. Also good. According to a twelfth aspect of the present invention, if the electrode lead-out portion is exposed from the piezoelectric lead-out portion, the second plug avoids the piezoelectric lead-out portion and the exposed portion of the electrode lead-out portion is exposed. It may be connected to the part.

  In addition, when the inter-element wiring is divided by the first wiring on the insulating layer, as described in claim 13, the relay wiring includes the upper electrode and the second piezoelectric element of the first piezoelectric element. The upper electrode layer of the device is separated from any of the upper electrodes in the same layer, and is formed of an upper metal layer formed so as to cross the first wiring along the lateral direction, and is separated from the upper metal layer. Furthermore, a plug for connecting each inter-element wiring may be further included.

  According to this configuration, similarly to the fourth aspect, since the relay wiring is separated from each of the upper electrodes of the first and second piezoelectric elements, each electrode of the first and second piezoelectric elements (upper electrode) In addition, the relay wiring can be electrically insulated from the lower electrode). Therefore, the first piezoelectric element and the second piezoelectric element can be connected in series by appropriately setting the connection target on the side opposite to the connection side with the relay wiring in the inter-element wiring, or connected in parallel. You can also.

Further, as described in claim 14, when the inter-element wiring is made of aluminum and the upper metal layer is made of iridium, of the wirings constituting the circuit connecting the first piezoelectric element and the second piezoelectric element. The wiring (iridium wiring) having a lower electrical conductivity than aluminum can be retained in the upper metal layer portion. Therefore, even when the distance between the first piezoelectric element and the second piezoelectric element is long, if the inter-element wiring is used up to the vicinity of the first wiring, the average electrical conductivity between the first piezoelectric element and the second piezoelectric element. Can be suppressed. The iridium wiring is not limited to a wiring made of only Ir, but is a concept including a wiring mainly containing Ir, such as Ir / IrO ₂₋ .

  In addition, as described in claim 15, the first piezoelectric element and the second piezoelectric element may be detection elements arranged to detect deformation of the thin film portion.

It is a typical top view of a motion sensor concerning one embodiment of the present invention. It is the typical perspective view of the motion sensor shown in FIG. 1, Comprising: It is the figure which represented one part by the cross section. It is a principal part enlarged view of the beam shown in FIG. FIG. 4 is an enlarged view of a main part of the beam shown in FIG. 1 and shows only the piezoresistive element and the elements formed in the same layer as the piezoresistive element in FIG. 3. FIG. 4 is an enlarged view of a main part of the beam shown in FIG. 1, showing only the lower electrode and the piezoelectric body of FIG. 3 and elements formed in the same layer as them. FIG. 4 is an enlarged view of a main part of the beam shown in FIG. 1 and shows only the upper electrode and the elements formed in the same layer as the upper electrode in FIG. 3. It is sectional drawing showing the cut surface AA of the beam shown in FIG. It is sectional drawing showing the cut surface BB of the beam shown in FIG. It is typical sectional drawing which shows a part of manufacturing process of the motion sensor shown in FIG. 1, Comprising: The same cross section as FIG. 8 is represented. It is a figure which shows the next process of FIG. 9A. It is a figure which shows the next process of FIG. 9B. It is a figure which shows the next | following process of FIG. 9C. It is a figure which shows the 1st modification of the beam shown in FIG. It is a figure which shows the 2nd modification of the beam shown in FIG. It is a figure which shows the 3rd modification of the beam shown in FIG. It is a figure which shows the 4th modification of the beam shown in FIG. It is a figure which shows the 5th modification of the beam shown in FIG. It is a figure which shows the 6th modification of the beam shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
<Overall configuration of motion sensor 1>
FIG. 1 is a schematic plan view of a motion sensor 1 according to an embodiment of the present invention. FIG. 2 is a schematic perspective view of the motion sensor 1 shown in FIG.

The motion sensor 1 is a six-axis motion sensor that detects three-axis acceleration acting along three axes (X-axis, Y-axis, and Z-axis) orthogonal in a three-dimensional space and three-axis angular velocity acting around the three axes. .
The motion sensor 1 includes an SOI (Silicon On Insulator) substrate 2 having a rectangular shape in plan view as a semiconductor substrate having a front surface 21 and a back surface 22. The front surface 21 of the SOI substrate 2 is an element formation surface on which, for example, a detection element or a detection circuit is formed, and the back surface 22 is a mounting to which a support substrate (for example, a sealing substrate such as a glass substrate) is bonded. Surface.

  For convenience of explanation, in the following, the direction parallel to one pair of opposite sides of the SOI substrate 2 is defined as the X direction, and the direction parallel to the other pair of opposite sides of the SOI substrate 2 is defined as the Y direction. This embodiment will be described with the direction parallel to the Z direction as the Z direction. When the SOI substrate 2 is placed on a horizontal plane, the X direction and the Y direction become two horizontal directions (first horizontal direction and second horizontal direction) along two horizontal straight lines (X axis and Y axis) orthogonal to each other, The Z direction is a vertical direction (height direction) along a vertical straight line (Z axis). Note that the Z direction may be referred to as the vertical direction with reference to the basic posture of the motion sensor 1 in which the back surface 22 of the SOI substrate 2 is disposed on the lower side.

  The SOI substrate 2 has a structure in which a silicon substrate 3, an insulating layer 4 made of silicon oxide, and an active layer 5 made of silicon are stacked in order from the back surface 22 side to the front surface 21 side. The total thickness of the SOI substrate 2 is, for example, about 557.5 μm, and the thickness of each layer is, for example, the silicon substrate 3 is about 550 μm, the insulating layer 4 is about 1.5 μm, and the active layer 5 is about 6 μm. .

The SOI substrate 2 has a frame 6, a weight 7, and a beam 8 as a thin film portion. In this embodiment, the frame 6 and the weight 7 are configured by a laminated structure including the silicon substrate 3 of the SOI substrate 2, the insulating layer 4 and the active layer 5, and the beam 8 is configured by the active layer 5 of the SOI substrate 2. Yes.
The frame 6 is formed in a square shape (frame shape) in plan view. A plurality of electrode pads 9 connected to various wirings 29 to 35 (described later) formed on the SOI substrate 2 are provided on the frame 6. The plurality of electrode pads 9 are provided in the same number (10 in this embodiment) on each side of the frame 6 and are arranged at equal intervals on each side.

  The weight 7 is disposed in a region surrounded by the frame 6 with a space between the weight 6. The weight 7 includes a square columnar central columnar portion 10 and four rectangular columnar peripheral columnar portions 11 around it. Each of the central columnar part 10 and each peripheral columnar part 11 has the same thickness (height) as the frame 6. The central columnar part 10 is arranged in the central part of the region surrounded by the frame 6 so that the outer peripheral edge is parallel to the inner peripheral edge (inner surface) of the frame 6. The peripheral columnar portions 11 are arranged one by one on an extension line to both sides of each diagonal line on the upper surface of the central columnar portion 10. Then, one corner of the side surface of the peripheral columnar portion 11 is connected to each corner of the side surface of the central columnar portion 10. Thus, the central columnar portion 10 and the four peripheral columnar portions 11 are integrated to form a weight 7 having the same thickness as the frame 6.

  Four beams 8 are provided in this embodiment, and extend in parallel with each other between the adjacent columnar portions 11 adjacent to each other with a space from the side surfaces of the peripheral columnar portions 11. One end of the beam 8 is connected to the frame 6 in the longitudinal direction (hereinafter, this direction is sometimes referred to as “longitudinal direction of the beam 8”), and the other end is connected to the central columnar portion 10. Further, the beam 8 is composed of the active layer 5 of the SOI substrate 2, so that it can be twisted and bent. Thus, the four beams 8 support the weight 7 so as to be able to oscillate with respect to the frame 6.

Each beam 8 is provided with a drive piezoelectric element 12 and a detection piezoelectric element 13 as a capacitive element, and a piezoresistive element 14.
A total of four drive piezoelectric elements 12 are provided at the boundary between each beam 8 and the frame 6, and are arranged so as to straddle between the beam 8 and the frame 6. An AC voltage for causing the weight 7 to circulate along the circumferential direction of the frame 6 is applied to the drive piezoelectric element 12.

  A plurality of detection piezoelectric elements 13 are provided at the boundary between each beam 8 and the central columnar portion 10 (three in this embodiment), and detect angular velocity components acting on the sensor. A plurality of elements provided at each boundary are arranged along a width direction (hereinafter, sometimes referred to as “transverse direction of the beam 8”) that is perpendicular to the longitudinal direction of the beam 8 with a space therebetween. These are arranged so as to straddle between the beam 8 and the central columnar part 10.

  A plurality of piezoresistive elements 14 are provided for each beam 8. The plurality of piezoresistive elements 14 constitute, for example, three bridge circuits including four piezoresistive elements 14 as detection circuits for acceleration acting on the X axis, the Y axis, and the Z axis. For example, the bridge circuit corresponding to the X axis is configured by four piezoresistive elements 14 on the beam 8 extending along the X direction, and the bridge circuit corresponding to the Y axis is on the beam 8 extending along the Y direction. 4 piezoresistive elements 14. In addition, the bridge circuit corresponding to the Z axis is configured by a total of four piezoresistive elements 14 selected one by one from each of the four beams 8. In FIGS. 1 and 2, only a part of the plurality of piezoresistive elements 14 is shown.

  In this motion sensor 1, by applying an alternating drive voltage to the drive piezoelectric element 12, the beam 8 is three-dimensionally oscillated, and the weight 7 rotates around the frame 6 in the circumferential direction. When the angular velocity is applied to the motion sensor 1 and a Coriolis force corresponding to the applied angular velocity and the velocity of the weight 7 is generated in the weight 7, the beam 8 is distorted. Due to the distortion of the beam 8, a stress acts on the detection piezoelectric element 13 on the beam 8, and the stress is converted into a voltage by the detection piezoelectric element 13. Therefore, if the voltage generated in the detection piezoelectric element 13 is taken out as a signal, the triaxial angular velocity acting on the motion sensor 1 can be detected.

In addition, when acceleration acts on the motion sensor 1 and the weight 7 swings, inertial force acts on the weight 7 and distortion occurs in the beam 8. Due to the distortion of the beam 8, stress acts on the piezoresistive element 14 on the beam 8, and the resistivity of the piezoresistive element 14 changes. Therefore, if the amount of change in the resistivity of each piezoresistive element 14 is taken out as a signal, the triaxial acceleration acting on the motion sensor 1 can be detected based on the signal.
<Arrangement Form of Piezoresistive Element 14, Drive Piezoelectric Element 12, and Detection Piezoelectric Element 13 on Beam 8>
3 to 6 are enlarged views of main parts of the beam 8 shown in FIG. FIG. 4 shows only the piezoresistive element 14 and the elements formed in the same layer as the piezoresistive element 14 in FIG. FIG. 5 shows only the lower electrode and the piezoelectric body of FIG. 3 and elements formed in the same layer as them. FIG. 6 shows only the upper electrode in FIG. 3 and elements formed in the same layer as the upper electrode. FIG. 7 is a cross-sectional view showing a section AA of the beam 8 shown in FIG. FIG. 8 is a cross-sectional view showing a section BB of the beam 8 shown in FIG.

First, referring to FIGS. 3 to 4 and FIGS. 7 to 8, a piezoresistive element 14 as a strain gauge is formed as a part of the surface layer portion of the beam 8. The piezoresistive element 14 is an element formed by imparting conductivity by diffusion of p-type impurities into the n ⁻ -type active layer 5, for example, and has a uniform p-type impurity concentration.
In this embodiment, the piezoresistive element 14 is, for example, a first resistor constituting a bridge circuit for detecting an X direction as a first bridge circuit (that is, a bridge circuit for detecting acceleration in the X direction). constituting the X- resistance element R _X, the bridge circuit for the Z direction detected as a different second bridge circuit to the bridge circuit for the X-direction detecting (i.e., the bridge circuit for detecting the acceleration in the Z-direction) and a Z- resistive elements R _Z of the second resistor.

The first and second resistors exemplified as the X-direction and Z-direction detection resistors are designed for X-direction detection, Y-direction detection, and Z-direction detection according to the characteristics of the final product, for example. be able to.
X- resistive element R _X and Z- resistive element R _Z are each being formed in an elongated shape along the longitudinal direction of the beam 8 in the width direction center of the beam 8, are arranged along the longitudinal direction of the beam 8 ing. Specifically, so as to extend between the beam 8 and the frame 6, and is disposed Z- resistive element R _Z so as to overlap with the driving piezoelectric element 12 in plan view, the frame from the X- resistive element R _X toward a direction away from 6 X- resistive element _R X, they are arranged in that order X- resistive element _{R X} and Z- resistance element _{R Z.}

Next, referring to FIGS. 3, 5, and 7 to 8, the surface 21 of the SOI substrate 2 has a first interlayer made of SiO ₂ film 15 (about 125 mm thick) and NSG (Nondoped Silicate Glass). A film 16 (having a thickness of about 2500 mm) is sequentially laminated.
The drive piezoelectric element 12 and the detection piezoelectric element 13 are provided on the first interlayer film 16.

Driving the piezoelectric element 12, the beam 8 and Z- resistive element disposed on the boundary between the frame 6 R _Z and the Z- resistive element R _Z in adjacent X- resistive element consisting of R _X 1 pair of piezoresistive elements 14 It is arranged to cover.
The driving piezoelectric element 12 includes a piezoelectric body 17 as a dielectric (for example, PZT (lead zirconate titanate)), and a pair of upper electrodes 18 (for example, Pt / Ti) that sandwich the piezoelectric body 17 from both sides in the vertical direction. And a lower electrode 19 (for example, Ir / IrO ₂ ).

The detection piezoelectric element 13 is provided on the side farther from the frame 6 with respect to the drive piezoelectric element 12 with an interval.
Detecting piezoelectric elements 13, in this embodiment, the X- detection element D _X for detecting the angular velocity around the X-direction as a first direction, around the Z direction as a second direction different from the X direction and a Z- detection element D _Z for detecting the angular velocity.

Z- detection element D _Z is arranged in the center in the width direction of the beam 8, the Z- detection element D _Z X- detecting elements on both sides in the width direction of the beam 8 with respect to D _X is arranged.
Note that the first and second detection elements exemplified as the elements for detecting the X direction and the Z direction are, for example, for detecting the X direction, for detecting the Y direction, and for detecting the Z direction according to the characteristics of the final product. Can be designed as

The X-detecting element D _X and the Z-detecting element D _Z include a piezoelectric body 23 as a dielectric (for example, PZT (lead zirconate titanate)), and upper electrodes 24X sandwiching the piezoelectric body 23 from both sides in the vertical direction. 24Z (for example, Pt / Ti) and a lower electrode 25 (for example, Ir / IrO ₂ ).
In the detection piezoelectric element 13, piezoelectric body 23 and the lower electrode 25 is shared between X- detector elements _{D X} and Z- detecting element _{D Z.} The piezoelectric body 23 and the lower electrode 25 is different from the set of piezoresistive elements 14 covered by the driving piezoelectric elements 12, X- resistive element _{R X} and the X- resistive element Z- resistive element adjacent to _{R X} R It is arranged so as to cover another set of piezoresistive elements 14 made of _Z.

That is, in this embodiment, the widthwise central portion of the beam 8, the lower electrode 25, Z- detection element D _Z comprising a laminate structure in which piezoelectric 23 and the upper electrode 24Z are sequentially stacked is formed. The lower electrode 25 and the piezoelectric body 23 constituting the _Z -detecting element DZ have lead-out portions that are pulled out by substantially the same length on both sides in the width direction of the beam 8. X-detection element D _X is on both sides in the width direction of the beam 8 of the upper electrode 24Z of the _Z -detection element DZ on the extraction part of the lower electrode 25, the extraction part of the piezoelectric body 23, and further on the extraction part of the piezoelectric body 23. The upper electrodes 24X are formed one by one at a distance from the upper electrode 24Z. In this embodiment, Z- X- detector elements D _X in the one widthwise side of the beam 8 with respect to the detection device D _Z (upper side in FIG. 3 and FIG. 5), an example of a first piezoelectric element of the present invention There, the other side X- detector elements D _X of (lower side in FIG. 3 and FIG. 5) is an example of a second piezoelectric element of the present invention.

On the first interlayer film 16, a second interlayer film 20 (thickness of about 5000 mm) made of SiO ₂ covering the drive piezoelectric element 12 and the detection piezoelectric element 13 is laminated. An electrode pad 9 is formed on the second interlayer film 20 as an insulating layer.
On the second interlayer film 20, a PSG (Phosphorus Silicate Glass) film 26 (thickness of about 750 mm) and a SiN film 27 (thickness of about 7000 mm) are sequentially laminated. In the PSG film 26 and the SiN film 27, a pad opening 28 for exposing the electrode pad 9 is formed.
<Wiring structure on beam 8>
Next, referring to FIG. 3 to FIG. 8, on the SOI substrate 2, wiring 29 for supplying power from the electrode pad 9 to various elements such as the driving piezoelectric element 12, the detecting piezoelectric element 13, and the piezoresistive element 14. ~ 35 are laid.

The wirings 29 to 35 are a driving upper electrode wiring 29 that supplies power to the upper electrode 18 of the driving piezoelectric element 12, a driving lower electrode wiring 30 that supplies power to the lower electrode 19 of the driving piezoelectric element 12, and an X-resistance element R. _X -bridge wiring 31 for supplying power to X, Z-bridge wiring 32 for supplying power to _Z -resistance element RZ, X-detection upper electrode wiring for supplying power to upper electrode 24X of _X -detection element D _X 34, Z- detecting element supplying power to the lower electrode 25 that is shared by _D for supplying power to the upper electrode 24Z of _Z Z- detecting upper electrode wiring 33, and X- detection element _{D X} and Z- detector elements _{D Z} The detection lower electrode wiring 35 is included.

These wirings 29 to 35 include a main wiring 36 formed in the same layer as the electrode pad 9 (specifically, on the second interlayer film 20), and a sub wiring 37D formed in a layer lower than the main wiring 36. , 37M.
The wiring from the electrode pad 9 to various elements is essentially the same layer as the electrode pad 9 using a material selected in consideration of internal resistance and the like from the start end (electrode pad 9) to the end. It is preferable that the main wiring 36 is laid on. However, the wiring space on the SOI substrate 2 is limited, and if there are a large number of wirings in the space, the wirings constituting different circuits may come into contact with each other. Therefore, in this embodiment, the main wiring 36 of the same layer of the electrode pad 9 and the lower diffusion wiring 37D (specifically, the surface layer portion of the active layer 5 of the SOI substrate 2) of the same layer as the piezoresistive element 14 (see FIG. 4), and sub-wiring such as lower metal wiring 37M (wiring shown in FIG. 5) on the same layer (specifically on the first interlayer film 16) as the lower electrodes 19 and 25. By forming the wirings 29 to 35 in combination, the problem of contact between wirings is avoided. Note that some wirings are constituted only by the main wiring 36.

The main wiring 36 is a wiring made of Al in this embodiment. Similar to the piezoresistive element 14, the lower layer diffusion wiring 37 </ b> D (sub wiring) is a wiring formed by imparting conductivity to the active layer 5 partially by impurity diffusion. The lower layer metal wiring 37M (sub wiring) is a wiring made of the same material as the lower electrodes 19 and 25 (Ir / IrO _{2 in} this embodiment). A dummy piezoelectric body 38 made of the same material (for example, PZT (lead zirconate titanate)) as the piezoelectric body 17 of the driving piezoelectric element 12 and the piezoelectric body 23 of the detection piezoelectric element 13 is disposed on the lower layer metal wiring 37M. Is formed.

The driving upper electrode wiring 29 is composed of only the main wiring 36 and is electrically connected to the upper electrode 18 of the driving piezoelectric element 12. Similarly, the driving lower electrode wiring 30 is composed of only the main wiring 36 and is electrically connected to the lower electrode 19 of the driving piezoelectric element 12.
The X-bridge wiring 31 is laid on the beam 8 so as to traverse the beam 8 and connects a plurality of X-resistance elements _RX in series. The X-bridge wiring 31 is composed of a combination of a main wiring 36 and a lower layer diffusion wiring 37D (sub wiring). The lower layer diffusion wiring 37 </ b> D as the sub wiring is laid in a portion overlapping the driving piezoelectric element 12 and the detection piezoelectric element 13 (Z−detection element D _Z ) in a plan view when the beam 8 is vertically cut. Further, the X-bridge wiring 31 (main wiring 36) extending along the longitudinal direction (longitudinal direction) of the beam 8 is branched in a region between the driving piezoelectric element 12 and the detection piezoelectric element 13. The branched main wiring 36 (branching wiring 39) extends to the peripheral edge of the beam 8 along the transverse direction (width direction) of the beam 8, and the peripheral edge of the beam 8 is laid along the longitudinal direction of the beam 8. ing.

Z- bridge wiring 32 is laid on the beam 8 so as to cross the beam 8, by connecting a plurality of Z- resistance elements R _Z in series. The Z-bridge wiring 32 is composed of a combination of a main wiring 36 and a lower layer diffusion wiring 37D (sub wiring). The lower layer diffusion wiring 37 </ b> D as the sub wiring is laid in a portion overlapping the driving piezoelectric element 12 and the detection piezoelectric element 13 (Z−detection element D _Z ) in a plan view when the beam 8 is vertically cut. Further, the Z-bridge wiring 32 (main wiring 36) extending along the longitudinal direction (longitudinal direction) of the beam 8 is branched in a region between the driving piezoelectric element 12 and the detection piezoelectric element 13. The branched main wiring 36 (branch wiring 40) has a peripheral edge of the beam 8 opposite to the peripheral edge portion of the beam 8 along which the X-bridge wiring 31 is routed along the transverse direction (width direction) of the beam 8. The peripheral edge of the beam 8 is laid along the longitudinal direction of the beam 8.

The Z-detection upper electrode wiring 33 is laid alongside the branch wiring 40 of the Z-bridge wiring 32 at the peripheral portion of the beam 8. Then, the X-detecting element D _X is turned in a U-shape in plan view toward the side close to the frame 6 in the vicinity of the end so as to surround the end on the side far from the frame 6 in the _X -detecting element D _X , and the upper part of the _Z -detecting element D _Z It is electrically connected to the electrode 24Z.
In this case, the Z-detection upper electrode wiring 33 (main wiring 36) extending along the longitudinal direction of the beam 8 extends in the transverse direction of the beam 8 in a region between the driving piezoelectric element 12 and the detection piezoelectric element 13. -It is divided by the branch wiring 40 (main wiring 36) of the bridge wiring 32. That is, in the relationship between the Z-detection upper electrode wiring 33 and the Z-bridge wiring 32, the branch wiring 40 of the Z-bridge wiring 32 is an example of the first wiring of the present invention, and is divided by the branch wiring 40. The Z-detection upper electrode wiring 33 is an example of the second wiring of the present invention.

  Therefore, in this embodiment, the lower metal layer of the present invention extends to the main wiring 36 of the Z-detection upper electrode wiring 33 so as to cross the Z-bridge wiring 32 (branch wiring 40) along the longitudinal direction of the beam 8. As an example, the relay wiring 41 is combined. The relay wiring 41 is configured by a lower layer metal wiring 37 </ b> M below the main wiring 36. Thereby, contact with Z-detection upper electrode wiring 33 and Z-bridge wiring 32 (branch wiring 40) can be prevented.

  The relay wiring 41 (the lower layer metal wiring 37M) is separated from both the lower electrode 19 of the driving piezoelectric element 12 and the lower electrode 25 of the detection piezoelectric element 13, and the length direction of the relay wiring 41 is provided thereon. A dummy piezoelectric body 38 is provided so as to expose both ends. The main wiring 36 of the Z-detection upper electrode wiring 33 and the relay wiring 41 (lower metal wiring 37M) of the Z-detection upper electrode wiring 33 are connected by a plug 42 penetrating the second interlayer film 20 in the thickness direction. It is connected. The plug 42 is connected to both ends of the relay wiring 41 while avoiding the dummy piezoelectric body 38.

X- detecting upper electrode wiring 34, across the Z- detection element _{D Z} in the width direction of the beam 8 facing each other, Z- upper electrode of the sensing element _{D Z} one side of the X- detection element _{D X} with respect to 24X including and inter-element wires 43 for electrically connecting the upper electrode 24X on the other side of the X- detection element D _X, the pad wiring 44 for electrically connecting the electrode pad 9 between the element wires 43 Yes.
The inter-element wiring 43 is laid so as to straddle the _X -detecting elements DX on one side and the other side in the width direction of the beam 8.

In this case, the inter-element wiring 43 (main wiring 36) of the X-detection upper electrode wiring 34 straddling the width direction of the beam 8 is a longitudinal section of the beam 8 in the vicinity of the side end portion far from the frame 6 in the _Z -detection element DZ. The X-bridge wiring 31 (main wiring 36) extending along the direction and the beam 8 are turned from the peripheral edge of the beam 8 to the side close to the frame 6 in a U shape in plan view and connected to the upper electrode 24Z of the _Z -detecting element DZ. The Z-detection upper electrode wiring 33 (main wiring 36) is divided. That is, in the relationship between the X-detection upper electrode wiring 34 (inter-element wiring 43), the X-bridge wiring 31 and the Z-detection upper electrode wiring 33, the X-bridge wiring 31 and the Z-detection upper electrode wiring 33 are The main wiring 36 of the inter-element wiring 43 divided by the X-bridge wiring 31 and the Z-detection upper electrode wiring 33 is an example of the second wiring of the present invention. .

  Therefore, in this embodiment, the lower metal layer of the present invention extends to the main wiring 36 of the inter-element wiring 43 so as to cross the X-bridge wiring 31 and the Z-detection upper electrode wiring 33 along the transverse direction of the beam 8. As an example, the relay wiring 45 is combined. The relay wiring 45 is configured by a lower layer metal wiring 37 </ b> M below the main wiring 36. As a result, contact between the X-detection upper electrode wiring 34 and the X-bridge wiring 31 and the Z-detection upper electrode wiring 33 can be prevented.

  The relay wiring 45 (lower metal wiring 37M) is separated from both the lower electrode 19 of the drive piezoelectric element 12 and the lower electrode 25 of the detection piezoelectric element 13, and above that, the length direction of the relay wiring 45 is provided. A dummy piezoelectric body 38 is provided so as to expose both ends. The main wiring 36 of the X-detection upper electrode wiring 34 and the relay wiring 45 (lower metal wiring 37M) of the X-detection upper electrode wiring 34 are connected by a plug 46 that penetrates the second interlayer film 20 in the thickness direction. It is connected. The plug 46 is connected to both ends of the relay wiring 45 so as to avoid the dummy piezoelectric body 38.

The pad wiring 44 is laid alongside the branch wiring 39 of the X-bridge wiring 31 at the periphery of the beam 8. Then, while the bent along the end portion of the side far from the frame 6 in the X- detector elements D _X side, is electrically connected to the element-to-element line 43.
In this case, the pad wiring 44 (main wiring 36) extending along the longitudinal direction of the beam 8 is an X-bridge wiring 31 extending in the transverse direction of the beam 8 in a region between the driving piezoelectric element 12 and the detection piezoelectric element 13. This is divided by the branch wiring 39. That is, in the relationship between the X-detection upper electrode wiring 34 (pad wiring 44) and the X-bridge wiring 31, the branch wiring 39 of the X-bridge wiring 31 is an example of the first wiring of the present invention. The main wiring 36 of the pad wiring 44 divided by the branch wiring 39 is an example of the second wiring of the present invention.

  Therefore, in this embodiment, as an example of the lower metal layer of the present invention that extends to the main wiring 36 of the pad wiring 44 across the X-bridge wiring 31 along the longitudinal direction of the beam 8 and extends directly below the electrode pad 9. The relay wiring 47 is combined. The relay wiring 47 is configured by a lower layer metal wiring 37M below the main wiring 36. Thereby, contact between the X-detection upper electrode wiring 34 (pad wiring 44) and the X-bridge wiring 31 can be prevented. The electrode pad 9 and the relay wiring 47 of the X-detection upper electrode wiring 34 are connected by a plug 48 that penetrates the second interlayer film 20 in the thickness direction.

Detecting lower electrode wiring 35 is integrally connected to the lower electrode 25 that is shared by X- detector elements D _X and Z- detecting element D _Z. In FIG. 3, only the lower metal wiring 37M (sub wiring) is shown as the detection lower electrode wiring 35.
<Manufacturing method of motion sensor 1>
9A to 9D are schematic cross-sectional views showing the manufacturing process of the motion sensor 1 shown in FIG. 1 in the order of steps, and show the same cross section as FIG.

In order to manufacture the motion sensor 1, first, as shown in FIG. 9A, a p-type impurity is doped into the active layer 5 of the SOI substrate 2 including the silicon substrate 3, the insulating layer 4, and the active layer 5. Resistance element 14 and lower layer diffusion wiring 37D are formed. Next, the SiO ₂ film 15 and the first interlayer film 16 are sequentially formed on the SOI substrate 2 by, for example, a CVD (Chemical Vapor Deposition) method.

Next, as shown in FIG. 9B, a metal material made of Ir / IrO ₂ , a piezoelectric material made of PZT, and a metal material made of Pt / Ti are sequentially stacked on the first interlayer film 16 by a known sputtering technique. . Thereafter, Ir / IrO ₂ is selectively etched by a known patterning technique, and further, PTZ is selectively etched. By the etching of the piezoelectric material, the piezoelectric body 17 of the drive piezoelectric element 12, the piezoelectric body 23 of the detection piezoelectric element 13, and the dummy piezoelectric body 38 are simultaneously formed. Subsequently, by selectively etching Pt / Ti, the lower electrode 19 of the driving piezoelectric element 12, the lower electrode 25 of the detecting piezoelectric element 13, and the lower layer metal wiring 37M (including the relay wirings 41, 45, and 47) are formed. Formed simultaneously.

  Next, as shown in FIG. 9C, the second interlayer film 20 is laminated on the first interlayer film 16 so as to cover the drive piezoelectric element 12 and the detection piezoelectric element 13. Next, the second interlayer film 20 is selectively etched, so that a contact hole for making contact with the lower layer metal wiring 37M constituting the relay wiring 41, 45, 47 is formed. Next, a metal material (for example, Al) for the electrode pad 9 and the main wiring 36 is sputtered, and this metal material is patterned, whereby the electrode pad 9, the main wiring 36 of various wirings, and the plugs 42, 46, and 48 are formed. Formed simultaneously.

Next, as shown in FIG. 9D, the PSG film 26 and the SiN film 27 are sequentially stacked on the second interlayer film 20. Then, a pad opening 28 is formed so as to penetrate the PSG film 26 and the SiN film 27 by a known etching technique. Subsequently, the silicon substrate 3 is ground from the back surface 22. After grinding, a mask (not shown) made of a photoresist is formed on a region where the weight 7 and the frame 6 are to be formed by a known patterning technique. The SOI substrate 2 is dry-etched from the back surface 22 side to the middle of the silicon substrate 3 through this mask. Thereby, the shapes of the weight 7 and the frame 6 are formed, and at the same time, a groove separating the weight 7 and the frame 6 is formed. Thereafter, an etching solution is supplied into the groove, whereby the insulating layer 4 in the groove is removed by wet etching, and at the same time, a beam 8 composed of the active layer 5 is formed. Through the above steps, the motion sensor 1 shown in FIGS. 1 to 8 is obtained.
<Operational effects of this embodiment>
As described above, according to the motion sensor 1, as shown in FIG. 8, the Z-detection upper electrode wiring 33 (mainly divided by the branch wiring 40 of the Z-bridge wiring 32 on the second interlayer film 20. The wiring 36) is electrically connected to each other via a relay wiring 41 formed in the same layer as the lower electrode 19 of the drive piezoelectric element 12 and the lower electrode 25 of the detection piezoelectric element 13. Thereby, conduction of the Z-detection upper electrode wiring 33 (main wiring 36) can be achieved so as not to contact the Z-bridge wiring 32.

In addition, as shown in FIG. 9B, when forming the lower electrode 19 of the drive piezoelectric element 12 and the lower electrode 25 of the detection piezoelectric element 13, a wiring that forms a detour of the Z-detection upper electrode wiring 33 (main wiring 36) ( The relay wiring 41) can be formed simultaneously. Therefore, an increase in the number of steps can be prevented, and an increase in manufacturing cost can be suppressed.
In particular, even when various wirings 29 to 35 are laid on the thin film beam 8 as in the motion sensor 1, the Z-detection is used to form the base of the relay wiring 41 intersecting the Z-bridge wiring 32. There is no need to further stack an interlayer film on the second interlayer film 20 which becomes the base of the upper electrode wiring 33 (main wiring 36). For this reason, it is possible to suppress an excessive stress from being applied to the beam 8. As a result, acceleration and angular velocity can be detected with high accuracy by the motion sensor 1.

  Further, the relay wiring 41 is formed separately from the lower electrode 19 of the drive piezoelectric element 12 and the lower electrode 25 of the detection piezoelectric element 13. Therefore, most of the Z-detection upper electrode wiring 33 may be formed of Al wiring (main wiring 36), and the Pt wiring (lower metal wiring 37M) having a lower electrical conductivity than Al may be retained at the relay wiring 41. it can. As a result, a decrease in the average electrical conductivity of the Z-detection upper electrode wiring 33 can be suppressed.

  A dummy piezoelectric body 38 is formed on the relay wiring 41. Therefore, when the piezoelectric material is etched in the step shown in FIG. 9B, the portion of the relay wiring 41 immediately below the dummy piezoelectric body 38 can be protected from the etching gas. By this protection, damage to the relay wiring 41 can be suppressed, and the thickness of the relay wiring 41 can be maintained. As a result, an increase in internal resistance of the relay wiring 41 can be suppressed.

  Further, as shown in FIG. 7, the inter-element wiring 43 (main wiring 36) of the X-detection upper electrode wiring 34 divided by the X-bridge wiring 31 and the Z-detection upper electrode wiring 33 on the second interlayer film 20. ) Are electrically connected to each other via a relay wiring 45 formed in the same layer as the lower electrodes 19 and 25 of the driving piezoelectric element 12 and the detecting piezoelectric element 13. Thereby, the inter-element wiring 43 (main wiring 36) of the X-detection upper electrode wiring 34 can be conducted so as not to contact the X-bridge wiring 31 and the Z-detection upper electrode wiring 33.

Also in this case, the effects such as the suppression of the manufacturing cost, the improvement of the detection accuracy, the suppression of the decrease in the average electrical conductivity of the wiring, and the suppression of the increase in the internal resistance of the relay wiring 45 can be exhibited.
In particular, the relay wiring 45 is formed separately from the lower electrode 19 of the drive piezoelectric element 12 and the lower electrode 25 of the detection piezoelectric element 13. Therefore, the relay wiring 45 can be electrically insulated from the lower electrode 25 of the detection piezoelectric element 13. Therefore, as in this embodiment, by the upper electrode 24X two X- detector element D _X the connection target of the inter-element wires 43, to be connected between two X- detector elements D _X in parallel it can.

  Further, as shown in FIG. 3, the pad wiring 44 (main wiring 36) of the X-detection upper electrode wiring 34 divided on the second interlayer film 20 by the branch wiring 39 of the X-bridge wiring 31 is also the same. The drive piezoelectric element 12 and the detection piezoelectric element 13 are electrically connected to each other through a relay wiring 47 formed in the same layer as the lower electrodes 19 and 25 of the detection piezoelectric element 13. Accordingly, the pad wiring 44 (main wiring 36) of the X-detection upper electrode wiring 34 can be conducted so as not to contact the branch wiring 39 of the X-bridge wiring 31.

Also in this case, effects such as suppression of the manufacturing cost, improvement of detection accuracy, suppression of decrease in average electrical conductivity of the wiring, and suppression of increase in internal resistance of the relay wiring 47 can be exhibited.
<Variation of relay wiring>
10-15 is a figure which shows the 1st-6th modification of the beam 8 shown in FIG. 7, respectively.
The relay wiring of the main wiring 36 forming a certain circuit is not limited to the form described in the above-described embodiment, but can be configured in other forms. 10-15, only the code | symbol required for description of a modification among the codes | symbols shown in FIGS. 1-8 is represented.

As shown in FIG. 10, the dummy piezoelectric body 38 provided on the relay wiring 45 that bypasses the inter-element wiring 43 (main wiring 36) of the X-detection upper electrode wiring 34 covers almost the entire surface of the relay wiring 45. It may be. In this case, the plug 46 may pass through the dummy piezoelectric body 38 and be connected to the relay wiring 45.
Further, as shown in FIG. 11, the dummy piezoelectric body 38 on the relay wiring 45 may be omitted.

FIG. 12 shows a mode in which the pad wiring 44 and the inter-element wiring 43 of the X-detection upper electrode wiring 34 are divided into the main wiring 36 of the X-bridge wiring 31.
As shown in FIG. 12, the relay wiring crosses the main wiring 36 of the X-bridge wiring 31 from the lower electrode 25 of the _X -detecting element D _X on the one side in the width direction of the beam 8 with respect to the Z-detecting element D _Z. Thus, the electrode lead portion 49 that is integrally drawn out may be used. Further, the dummy piezoelectric body 38 may be a piezoelectric body extraction portion 50 that is integrally extracted along the surface of the electrode extraction portion 49 from the piezoelectric body of the _X -detecting element DX.

In this configuration, since the relay wiring (electrode lead portion 49) and the lower electrode 25 of the _X -detecting element DX are integrally formed, the relay wiring (electrode lead portion 49) and the lower electrode 25 can be easily connected. And it can connect with a reliable structure.
Further, the pad wiring 44 and the upper electrode 24X of the _X -detecting element DX on one side are connected using the plug 51 as the first plug, and the inter-element wiring 43 and the electrode lead-out portion 49 are connected to the second plug. The plug 52 is connected through the piezoelectric lead portion 50, and the connection target at the end of the inter-element wiring 43 opposite to the plug 52 is the upper electrode of the _X -detection element DX on the other side. with 24X, with respect to the electrode pads 9, whereas it is possible to connect the side and the other side X- between detector elements D _X in series.

As shown in FIG. 13, the piezoelectric lead portion 50 may be drawn so as to expose the end portion of the electrode lead portion 49, and in this case, the plug 52 avoids the piezoelectric lead portion 50 and the electrode Connected to the drawer 49. Further, as shown in FIG. 14, the piezoelectric lead part 50 on the electrode lead part 49 may be omitted.
Further, as shown in FIG. 15, the relay wiring that bypasses the inter-element wiring 43 (main wiring 36) of the X-detection upper electrode wiring 34 is the upper electrode 18 of the driving piezoelectric element 12 and the upper electrode 24 </ b> X of the detection piezoelectric element 13. , 24Z and the upper metal layer 53 formed separately from these upper electrodes 18, 24X, 24Z. In this case, the inter-element wiring 43 and the upper metal layer 53 are connected by the plug 54.

As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.
For example, in the above-described embodiment, the gyro sensor is taken up as an example of the MEMS sensor. However, the present invention is not limited to the gyro sensor, and is applied to various devices such as an acceleration sensor and a pressure sensor manufactured by the MEMS technology. Can do.

In addition, the wiring structure employing the relay wiring described in the above embodiment is not limited to the wiring laid on the beam 8 but can be applied to the wiring laid on the frame 10.
In addition, various design changes can be made within the scope of matters described in the claims.

DESCRIPTION OF SYMBOLS 1 Motion sensor 2 SOI substrate 6 Frame 7 Weight 8 Beam 9 Electrode pad 10 Central columnar part 11 Peripheral columnar part 12 Drive piezoelectric element 13 Detection piezoelectric element 17 Piezoelectric body 18 (of drive piezoelectric element) Upper electrode 19 (of drive piezoelectric element) 19 Lower electrode (of driving piezoelectric element) 20 Second interlayer film 21 Front surface (of SOI substrate) 22 Back surface of (SOI substrate) 23 Piezoelectric body (of detection piezoelectric element) 24X (Upper electrode of X-detection element) 24Z (Z-) Upper electrode 25 (detection element) Lower electrode 31 X-bridge wiring 32 Z-bridge wiring 33 Z-detection upper electrode wiring 34 X-detection upper electrode wiring 36 Main wiring 37D Lower layer diffusion wiring 37M Lower layer metal wiring 38 Dummy piezoelectric element 39 Branch wiring (X-bridge wiring) 40 Branch wiring (Z-bridge wiring) 41 (Z-detection) Relay electrode (for upper electrode wiring) 42 Plug 43 Inter-element wiring (for X-detection upper electrode wiring) 44 Pad wiring (for X-detection upper electrode wiring) 45 Relay electrode (for inter-element wiring) 46 Plug 47 (Pad wiring) Relay electrode 48 plug 49 electrode lead-out part 50 piezoelectric lead-out part 51 plug 52 plug 53 upper metal layer 54 plug R _{X X} -resistance element R _Z Z-resistance element D _{X X} -detection element D _Z Z-detection element

Claims (15)

A semiconductor substrate;
A capacitive element provided on the semiconductor substrate and having a dielectric, and a lower electrode and an upper electrode facing each other with the dielectric interposed therebetween;
An insulating layer laminated on the semiconductor substrate and covering the capacitive element;
A main wiring formed on the insulating layer and including a first wiring and a second wiring divided by the first wiring on the insulating layer;
A relay wiring that is formed in the same layer as the lower electrode or the upper electrode, and extends across the first wiring along a horizontal direction along a surface of the lower electrode or the upper electrode in the layer;
The MEMS sensor, wherein the second wiring divided on the insulating layer is electrically connected to each other via the relay wiring. The semiconductor substrate has a thin film part that can be deformed by an external force and a frame that supports the thin film part,
The MEMS sensor according to claim 1, wherein the first wiring, the second wiring, and the relay wiring are laid on the thin film portion. The capacitive element includes a first piezoelectric element and a second piezoelectric element that are disposed on the thin film portion and each of the dielectrics is a piezoelectric body,
The second wiring on the thin film portion includes an inter-element wiring that electrically connects the first piezoelectric element and the second piezoelectric element, and a pad wiring that is electrically connected to the inter-element wiring. The MEMS sensor according to claim 2. The inter-element wiring is divided by the first wiring on the insulating layer,
The relay wiring is separated from both the lower electrode in the same layer as the lower electrode of the first piezoelectric element and the lower electrode of the second piezoelectric element, and crosses the first wiring along the lateral direction. Consisting of a lower metal layer formed as
The MEMS sensor according to claim 3, further comprising a plug that connects the lower metal layer and the divided inter-element wiring. The inter-element wiring is made of aluminum,
The MEMS sensor according to claim 4, wherein the lower metal layer is made of platinum.   The MEMS sensor according to claim 4, further comprising a dummy piezoelectric body formed on the lower metal layer and made of the same material as the piezoelectric bodies of the first piezoelectric element and the second piezoelectric element.   The MEMS sensor according to claim 6, wherein the plug penetrates the dummy piezoelectric body in a thickness direction and is connected to the lower metal layer. The lower metal layer is exposed from the dummy piezoelectric body;
The MEMS sensor according to claim 6, wherein the plug is connected to the exposed portion of the lower metal layer while avoiding the dummy piezoelectric body. The pad wiring and the inter-element wiring are divided by the first wiring on the insulating layer,
The relay wiring includes an electrode lead portion that is integrally drawn in the lateral direction so as to cross the first wiring from the lower electrode of the first piezoelectric element,
A first plug connecting the pad wiring and the upper electrode of the first piezoelectric element;
The MEMS sensor according to claim 3, further comprising a second plug that connects the inter-element wiring and the electrode lead portion.   10. The MEMS sensor according to claim 9, further comprising a piezoelectric lead portion that is integrally drawn from the piezoelectric body of the first piezoelectric element along a surface of the electrode lead portion.   The MEMS sensor according to claim 10, wherein the second plug penetrates the piezoelectric lead portion in the thickness direction and is connected to the electrode lead portion. The electrode lead portion is exposed from the piezoelectric lead portion,
The MEMS sensor according to claim 10, wherein the second plug is connected to the exposed portion of the electrode lead-out portion while avoiding the piezoelectric lead-out portion. The inter-element wiring is divided by the first wiring on the insulating layer,
The relay wiring is separated from both the upper electrode of the first piezoelectric element and the upper electrode of the second piezoelectric element in the same layer and crosses the first wiring along the lateral direction. Consisting of an upper metal layer formed as follows:
The MEMS sensor according to claim 3, further comprising a plug that connects the upper metal layer and each of the divided inter-element wirings. The inter-element wiring is made of aluminum,
The MEMS sensor according to claim 4, wherein the upper metal layer is made of iridium.   The MEMS sensor according to any one of claims 3 to 14, wherein the first piezoelectric element and the second piezoelectric element are detection elements arranged to detect deformation of the thin film portion.

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