JP2016176825A - Physical quantity sensor, method for manufacturing the same, electronic apparatus, and movable body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a physical quantity sensor that can increase the strength of joining between a functional element and a substrate.SOLUTION: A physical quantity sensor 100 includes: a substrate 10 with a recess 16; and a functional element 102 with a fixing part 130 fixed to the substrate 10. The substrate 10 has a projecting part 18 projecting from a wall 17 defining the recess 16, and the fixing part 130 is joined to the projecting part 18.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a physical quantity sensor, a manufacturing method thereof, an electronic device, and a moving object.

  In recent years, a physical quantity sensor that detects a physical quantity by using a silicon MEMS (Micro Electro Mechanical System) technology has been developed. In particular, acceleration sensors that detect acceleration and gyro sensors that detect angular velocity are rapidly expanding in applications such as a camera shake correction function of a digital still camera (DSC), an automobile navigation system, and a motion sensing function of a game machine. .

  In such a physical quantity sensor, for example, a concave portion may be formed on the substrate in order to arrange the movable body.

  For example, Patent Literature 1 discloses a gyro sensor including a first vibrating body and a second vibrating body that are disposed on a recess. The first vibrating body and the second vibrating body are fixed to the substrate by four fixing portions via four driving springs, respectively.

JP 2013-96952 A

  In the gyro sensor disclosed in Patent Document 1, in order to fix the fixing portion located at the boundary between the first vibrating body and the second vibrating body to the substrate, an independent island-shaped post portion is provided in the recess. There must be. However, it is difficult to form such independent island-shaped post portions in a desired shape in the manufacturing process. For example, when a recess is formed by multi-stage etching, the resist solution aggregates on the island-shaped post portion, and a part of the post portion (corner portion, etc.) is etched to obtain a post portion having a desired shape. It may not be possible.

  Thus, it is difficult to form the independent island-shaped post portion in a desired shape, and there is a problem that the bonding strength between the functional element and the substrate is lowered.

  One of the objects according to some embodiments of the present invention is to provide a physical quantity sensor capable of improving the bonding strength between a functional element and a substrate, and a method for manufacturing the same. Another object of some aspects of the present invention is to provide an electronic device including the physical quantity sensor and a moving object.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
The physical quantity sensor according to this application example is
A substrate having a recess;
A functional element having a fixing portion fixed to the substrate;
Including
The substrate has a protruding portion protruding from a wall portion defining the concave portion,
The fixed portion is joined to the protruding portion.

  In such a physical quantity sensor, since the fixed portion of the functional element is bonded to the protruding portion, for example, compared to the case where the fixed portion is bonded to an independent island-shaped post portion, the bonding between the functional element and the substrate is performed. Strength can be improved. For example, in an independent island-shaped post portion, when performing multi-stage etching, the resist solution aggregates on the post portion due to surface tension or the like, and it is difficult to form a desired shape. On the other hand, since the protruding portion protruding from the wall portion is continuous with the other surface of the substrate, the resist solution is less likely to aggregate compared to an independent island-shaped post portion and is formed in a desired shape. can do. As described above, in such a physical quantity sensor, since a portion (projecting portion) to be bonded to the functional element of the substrate can be formed in a desired shape, the bonding strength between the functional element and the substrate can be improved. .

[Application Example 2]
In the physical quantity sensor according to this application example,
The fixing portion may be electrically connected to an electrode provided on the protruding portion.

  In such a physical quantity sensor, for example, the fixed portion and the electrode are more reliably electrically connected as compared with a case where the fixed portion is electrically connected to an electrode provided on an independent island-shaped post portion. be able to.

[Application Example 3]
In the physical quantity sensor according to this application example,
The functional element has a spring portion connected to the fixed portion,
The spring portion may be located in a direction in which the protruding portion protrudes from the protruding portion.

  In such a physical quantity sensor, since the spring portion is positioned in the direction in which the protruding portion protrudes from the protruding portion, for example, the drive spring portion is positioned on the opposite side of the protruding portion from the protruding portion. Compared to the case, the apparatus can be downsized.

[Application Example 4]
In the physical quantity sensor according to this application example,
In plan view, the area of the fixed part may be larger than the area of the protruding part.

  In such a physical quantity sensor, for example, the bonding strength between the functional element and the substrate can be improved as compared with a case where the area of the fixed portion is equal to or smaller than the area of the protruding portion in plan view.

[Application Example 5]
The physical quantity sensor manufacturing method according to this application example is as follows:
Etching the first substrate to form a recess and a protrusion protruding from the wall defining the recess;
Bonding a second substrate to the protruding portion;
Etching the second substrate to form a functional element on the recess;
including.

  In such a physical quantity sensor manufacturing method, since the second substrate is bonded to the protruding portion, for example, compared to the case where the second substrate is bonded to the island-shaped post portion, the portion (the protruding portion) bonded to the functional element of the substrate. Part) can be formed in a desired shape, and the bonding strength between the functional element and the substrate can be improved.

[Application Example 6]
In the manufacturing method of the physical quantity sensor according to this application example,
A step of forming an electrode on the protruding portion may be included.

  In such a physical quantity sensor manufacturing method, since the electrode is formed on the protruding portion, the electrode can be formed in a desired shape and fixed, for example, compared to the case where the electrode is formed on an independent island-shaped post portion. The part and the electrode can be electrically connected more reliably.

[Application Example 7]
The electronic device according to this application example is
Any one of the physical quantity sensors described above is included.

  Since such an electronic device includes the electronic device according to this application example, the reliability can be improved.

[Application Example 8]
The mobile object according to this application example is
Any one of the physical quantity sensors described above is included.

  Since such a mobile body includes the electronic device according to this application example, reliability can be improved.

The top view which shows typically the physical quantity sensor which concerns on this embodiment. Sectional drawing which shows the physical quantity sensor which concerns on this embodiment typically. The top view which shows typically a part of physical quantity sensor which concerns on this embodiment. Sectional drawing which shows typically a part of physical quantity sensor which concerns on this embodiment. The flowchart which shows an example of the manufacturing method of the physical quantity sensor which concerns on this embodiment. The figure which shows typically the manufacturing process of the physical quantity sensor which concerns on this embodiment. The figure which shows typically the manufacturing process of the physical quantity sensor which concerns on this embodiment. The figure which shows typically the manufacturing process of the physical quantity sensor which concerns on this embodiment. The figure which shows typically the manufacturing process of the physical quantity sensor which concerns on this embodiment. The figure which shows typically the manufacturing process of the physical quantity sensor which concerns on this embodiment. The figure which shows typically the manufacturing process of the physical quantity sensor which concerns on this embodiment. The functional block diagram of the electronic device which concerns on this embodiment. FIG. 3 is a diagram showing an example of the appearance of an electronic apparatus according to the embodiment. FIG. 3 is a diagram showing an example of the appearance of an electronic apparatus according to the embodiment. The perspective view which shows the mobile body which concerns on embodiment typically.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. In addition, not all of the configurations described below are essential constituent requirements of the present invention.

1. Physical Quantity Sensor First, a physical quantity sensor (inertial sensor) according to this embodiment will be described with reference to the drawings. FIG. 1 is a plan view schematically showing a physical quantity sensor 100 according to the present embodiment. FIG. 2 is a cross-sectional view schematically showing the physical quantity sensor 100 according to the present embodiment, and is a cross-sectional view taken along the line II-II in FIG. In FIGS. 1 and 2, the X axis, the Y axis, and the Z axis are illustrated as three axes orthogonal to each other.

  The physical quantity sensor 100 is, for example, an acceleration sensor or a gyro sensor. Hereinafter, a case where the physical quantity sensor 100 is a gyro sensor capable of detecting the angular velocity ωy around the Y axis will be described.

  As shown in FIGS. 1 and 2, the physical quantity sensor 100 includes a substrate 10, a lid 20, and a functional element 102. For convenience, illustration of the lid 20 is omitted in FIG.

  The material of the substrate 10 is, for example, glass. The material of the substrate 10 may be silicon or the like. The substrate 10 has a first surface 12 and a second surface 14 facing the first surface 12 (facing in the direction opposite to the first surface 12).

  A recess 16 is formed in the first surface 12. The recess 16 constitutes the cavity 2. The recess 16 is a space surrounded by the wall 17 in plan view (as viewed from the thickness direction (Z-axis direction) of the substrate 10). The wall portion 17 is a side surface of the substrate 10 that defines the recess 16.

  The substrate 10 has a protrusion 18. The protruding portion 18 protrudes from the wall portion 17. In the illustrated example, the substrate 10 has two projecting portions 18, and the wall portion 17 on the + Y axis direction side (the wall portion 17 facing the −Y axis direction) extends from the wall portion 17 to the −Y axis direction. A protruding portion 18 protruding in the + Y-axis direction from the wall portion 17 is provided on the wall portion 17 on the −Y-axis direction side (the wall portion 17 facing the + Y-axis direction). Is provided. The protrusion 18 supports the functional element 102.

  FIG. 3 is a plan view schematically showing a part of the physical quantity sensor 100, and is a plan view of a region III in FIG. 4 is a cross-sectional view schematically showing a part of the physical quantity sensor 100, and is a cross-sectional view taken along the line IV-IV in FIG.

  As shown in FIGS. 3 and 4, the projecting portion 18 is provided with an electrode (contact portion) 4 and a wiring 6. In the illustrated example, the electrode 4 and the wiring 6 are provided in the groove 3 provided on the upper surface 18 a of the protrusion 18. An upper surface 18 a of the protrusion 18 is a part of the first surface 12 of the substrate 10 and is continuous with other regions of the first surface 12 of the substrate 10.

  The electrode 4 is electrically connected to the fixed part 130. The wiring 6 is electrically connected to the fixed portion 130 through the electrode 4. The wiring 6 is provided, for example, over the groove 3, the side surface of the protrusion 18, and the bottom surface of the recess 16. The wiring 6 is a wiring for electrically connecting the functional element 102 and an external terminal (not shown). The material of the wiring 6 and the electrode 4 is, for example, ITO (Indium Tin Oxide), aluminum, gold, platinum, titanium, tungsten, chromium, or the like. For convenience, the wiring 6 is not shown in FIGS. 1 and 2.

  The lid 20 is provided on the substrate 10. The material of the lid 20 is, for example, silicon. The lid 20 is bonded to the first surface 12 of the substrate 10. When the material of the substrate 10 is glass and the material of the lid 20 is silicon, the substrate 10 and the lid 20 may be joined by anodic bonding. In the illustrated example, a recess is formed in the lid 20, and the recess constitutes the cavity 2.

  In addition, the joining method of the board | substrate 10 and the cover body 20 is not specifically limited, For example, joining by low melting glass (glass paste) may be sufficient. Alternatively, the substrate 10 and the lid 20 may be joined by forming a metal thin film (not shown) at each joint portion of the substrate 10 and the lid 20 and eutectically bonding the metal thin films to each other. .

  The functional element 102 is provided on the first surface 12 side of the substrate 10. The functional element 102 is provided on the recess 16 and the substrate 10. The functional element 102 is bonded to the substrate 10 by, for example, anodic bonding or direct bonding.

  The functional element 102 is accommodated in the cavity 2 formed by the substrate 10 and the lid 20. The cavity 2 is preferably in a reduced pressure state (vacuum state). Thereby, it can suppress that the vibration of the functional element 102 attenuate | damps by air viscosity. The cavity 2 may be sealed in an inert gas (for example, nitrogen gas) atmosphere.

  In the physical quantity sensor 100, as shown in FIG. 1, the functional element 102 has two structures 112 (a first structure 112a and a second structure 112b). The two structures 112 are provided side by side in the X-axis direction so as to be symmetric with respect to an axis α parallel to the Y-axis.

  The structure 112 includes a fixed portion 130, a drive spring portion 132, a mass body (vibrating body) 134, a movable drive electrode portion 136, fixed drive electrode portions 138 and 139, a movable body 140, and a beam portion 142. The movable detection electrode unit 144 and the fixed detection electrode unit 146 are provided. The drive spring portion 132, the mass body 134, the movable drive electrode portion 136, the movable body 140, the beam portion 142, and the movable detection electrode portion 144 are provided on the recess 16 and are separated from the substrate 10.

  The fixing unit 130 is fixed to the substrate 10. The fixing unit 130 is bonded to the first surface 12 of the substrate 10 by, for example, anodic bonding. For example, four fixing portions 130 are provided for one structure 112. In the illustrated example, the structures 112a and 112b use the + X-axis direction fixing part 130 of the first structure 112a and the −X-axis side fixing part 130 of the second structure 112b as a common fixing part. . The common fixing portion 130 is provided on the protruding portion 18, for example.

  The fixing portion 130 (hereinafter also referred to as “fixing portion 130a”) provided on the protruding portion 18 is bonded to the upper surface 18a of the protruding portion 18 by, for example, anodic bonding or direct bonding. In plan view, the area of the fixing portion 130a is larger than the area of the protruding portion 18. In the illustrated example, the fixing portion 130 a covers the entire upper surface 18 a of the protruding portion 18. The fixing portion 130a is provided on the protruding portion 18 and the substrate 10 surrounding the functional element 102 in plan view. Therefore, for example, the bonding strength between the functional element 102 and the substrate 10 can be improved as compared with the case where the fixing portion is provided only on the protruding portion.

  The fixed part 130 a is electrically connected to the electrode 4. The fixed portion 130 a is electrically connected to the wiring 6 through the electrode 4. The wiring 6 is electrically connected to the drive spring portion 132, the mass body 134, the movable drive electrode portion 136, the movable body 140, the beam portion 142, and the movable detection electrode portion 144 via the fixed portion 130. Since the fixed portion 130 and the wiring 6 are electrically connected via the electrode 4, the drive spring portion 132, the mass body 134, the movable drive electrode portion 136, the movable body 140, the beam portion 142, and the movable detection electrode The portion 144 can be set to a desired potential. Although not shown, like the common fixing portion 130a, the other fixing portions 130 may be electrically connected to wiring (wiring for supplying a desired potential) via electrodes.

  The drive spring portion 132 connects the fixed portion 130 and the mass body 134. The drive spring part 132 is configured by a plurality of beam parts 133. A plurality of beam portions 133 are provided corresponding to the number of fixed portions 130. The beam portion 133 extends in the X-axis direction while reciprocating in the Y-axis direction. The beam portion 133 (the drive spring portion 132) can smoothly expand and contract in the X-axis direction, which is the vibration direction of the mass body 134.

  The beam portion 133 (drive spring portion 132) connected to the fixed portion 130 a provided on the protruding portion 18 is positioned in a direction in which the protruding portion 18 protrudes from the protruding portion 18. In the example shown in the drawing, the entire beam portion 133 is located in a direction in which the protruding portion 18 protrudes from the protruding portion 18. In the illustrated example, the beam portion 133 connected to the fixing portion 130a provided on the protruding portion 18 protruding in the −Y axis direction is located in the −Y axis direction from the protruding portion 18. Further, the beam portion 133 connected to the fixing portion 130a provided on the protruding portion 18 protruding in the + Y axis direction is located in the + Y axis direction with respect to the protruding portion 18.

  In the Y-axis direction, the distance D1 between the drive spring portion 132 (each beam portion 133) and the wall portion 17 is smaller than the distance D2 between the mass body 134 and the wall portion 17. Therefore, for example, as compared with the case where the distance between the drive spring portion and the wall portion is equal to or greater than the distance between the mass body and the wall portion, the apparatus can be reduced in size in the Y-axis direction.

  The mass body 134 is, for example, a rectangular frame body in plan view. The side surface of the mass body 134 in the X-axis direction (the side surface having a perpendicular line parallel to the X-axis) is connected to the drive spring portion 132. The mass body 134 can vibrate in the X-axis direction (along the X-axis) by the movable drive electrode portion 136 and the fixed drive electrode portions 138 and 139.

  The movable drive electrode portion 136 is provided on the mass body 134. In the illustrated example, four movable drive electrode portions 136 are provided, the two movable drive electrode portions 136 are positioned on the + Y-axis direction side of the mass body 134, and the other two movable drive electrode portions 136 have a mass. It is located on the −Y axis direction side of the body 134. As shown in FIG. 3, the movable drive electrode portion 136 is a comb including a trunk portion extending from the mass body 134 in the Y-axis direction and a plurality of branch portions extending from the trunk portion in the X-axis direction. It may have a tooth shape.

  The fixed drive electrode portions 138 and 139 are fixed to the substrate 10. The fixed drive electrode portions 138 and 139 are bonded to the first surface 12 of the substrate 10 by, for example, anodic bonding. The fixed drive electrode portions 138 and 139 are provided to face the movable drive electrode portion 136, and the movable drive electrode portion 136 is disposed between the fixed drive electrode portions 138 and 139. As shown in FIG. 1, when the movable drive electrode portion 136 has a comb-like shape, the fixed drive electrode portions 138 and 139 may have a comb-like shape corresponding to the movable drive electrode portion 136. Good.

  The movable body 140 is supported by the mass body 134 via a beam portion 142 serving as a rotation axis. The movable body 140 is provided inside the frame-shaped mass body 134 in plan view. The movable body 140 has a plate shape.

  The beam portion 142 is provided at a position shifted from the center of gravity of the movable body 140. In the illustrated example, the beam portion 142 is provided along the Y axis. The beam portion 142 can be torsionally deformed, and the movable body 140 can be displaced in the Z-axis direction by the torsional deformation.

  The movable detection electrode unit 144 is provided on the movable body 140. The movable detection electrode portion 144 is a portion of the movable body 140 that overlaps with the fixed detection electrode portion 146 in plan view. The movable detection electrode unit 144 can form a capacitance with the fixed detection electrode unit 146.

  The fixed part 130, the drive spring part 132, the mass body 134, the movable drive electrode part 136, the movable body 140, the beam part 142, and the movable detection electrode part 144 are integrally provided. The fixed portion 130, the drive spring portion 132, the mass body 134, the movable drive electrode portion 136, the fixed drive electrode portions 138 and 139, the movable body 140, the beam portion 142, and the movable detection electrode portion 144 (hereinafter, “movable body 140 etc.”) The material of (also referred to as) is, for example, silicon imparted with conductivity by doping impurities such as phosphorus and boron. The movable body 140 and the like constitute silicon MEMS (MEMS formed by processing a silicon substrate).

  The fixed detection electrode part (fixed electrode) 146 is fixed to the substrate 10 and provided to face the movable detection electrode part 144. The fixed detection electrode unit 146 is provided on the bottom surface of the recess 16. In the illustrated example, the planar shape of the fixed detection electrode unit 146 is a rectangle.

  The material of the fixed detection electrode unit 146 is, for example, aluminum, gold, or ITO. By using a transparent electrode material such as ITO as the fixed detection electrode portion 146, foreign substances or the like existing on the fixed detection electrode portion 146 can be easily visually recognized from the second surface 14 side of the substrate 10. The fixed detection electrode unit 146 is formed by, for example, film formation by sputtering or CVD, and patterning.

  Next, the operation of the physical quantity sensor 100 will be described.

  When a voltage is applied between the movable drive electrode portion 136 and the fixed drive electrode portions 138, 139 by a power source (not shown), an electrostatic force is generated between the movable drive electrode portion 136 and the fixed drive electrode portions 138, 139. be able to. Accordingly, the mass body 134 can be vibrated in the X-axis direction while the drive spring portion 132 is expanded and contracted in the X-axis direction.

  As shown in FIG. 1, in the first structure 112a, the fixed drive electrode portion 138 is disposed on the −X axis direction side of the movable drive electrode portion 136, and the fixed drive electrode portion 139 is + X of the movable drive electrode portion 136. It is arranged on the axial direction side. In the second structure 112b, the fixed drive electrode portion 138 is disposed on the + X axis direction side of the movable drive electrode portion 136, and the fixed drive electrode portion 139 is disposed on the −X axis direction side of the movable drive electrode portion 136. Yes. Therefore, the first alternating voltage is applied between the movable drive electrode portion 136 and the fixed drive electrode portion 138, and the first alternating voltage and the phase are shifted by 180 degrees between the movable drive electrode portion 136 and the fixed drive electrode portion 139. By applying the second alternating voltage, the mass body 134 of the first structure 112a and the mass body 134 of the second structure 112b are vibrated in the X-axis direction at a predetermined frequency and in opposite phase to each other. (Tuning fork type vibration).

  When the angular velocity ωy around the Y axis is applied to the physical quantity sensor 100 in a state where the mass body 134 is vibrating, the Coriolis force acts, and the movable body 140 of the first structure 112a and the second structure 112b The movable body 140 is displaced in directions opposite to each other in the Z-axis direction (along the Z-axis). The movable body 140 repeats this operation while receiving the Coriolis force.

  As the movable body 140 is displaced in the Y-axis direction, the distance between the movable detection electrode portion 144 and the fixed detection electrode portion 146 changes. For this reason, the capacitance between the movable detection electrode unit 144 and the fixed detection electrode unit 146 changes. By detecting the amount of change in capacitance between the electrode portions 144 and 146, the angular velocity ωy about the Y axis can be obtained.

  In addition, although the form (electrostatic drive system) which drives the mass body 134 with an electrostatic force was demonstrated above, the method to drive the mass body 134 is not specifically limited, A piezoelectric drive system and the Lorentz force of a magnetic field It is possible to apply an electromagnetic drive system using

  In the above description, the physical quantity sensor 100 is a gyro sensor that can detect the angular velocity ωy around the Y axis. However, the physical quantity sensor according to the present invention is a gyro sensor that can detect the angular velocity around the X axis. Alternatively, a gyro sensor that can detect an angular velocity around the Z axis may be used. In addition, the physical quantity sensor according to the present invention may be an acceleration sensor that detects acceleration in the X-axis direction, an acceleration sensor that detects acceleration in the Y-axis direction, or acceleration in the Z-axis direction. It may be an acceleration sensor to detect.

  In the above description, the physical quantity sensor including one functional element 102 has been described. However, the physical quantity sensor according to the present invention may include a plurality of functional elements. Thereby, the physical quantity sensor according to the present invention can detect the acceleration of the X axis, the Y axis, and the Z axis, and can detect the angular velocity around the X axis, the Y axis, and the Z axis. Also good. That is, the physical quantity sensor according to the present invention may have a function as an acceleration sensor and a function as a gyro sensor.

  The physical quantity sensor 100 has the following features, for example.

  In the physical quantity sensor 100, the substrate 10 has a protruding portion 18 that protrudes from the wall portion 17 that defines the recessed portion 16, and the fixed portion 130 is joined to the protruding portion 18. Therefore, for example, the bonding strength between the functional element 102 and the substrate 10 can be improved as compared with the case where the fixing portion is bonded to an independent island-shaped post portion. Further, in the physical quantity sensor 100, the fixed portion 130a is electrically connected to the electrode 4 provided on the protruding portion 18, and therefore, for example, the fixed portion 130a is electrically connected to the electrode provided on the island-shaped post portion where the fixed portion is independent. Compared with the case where it is connected to, the fixed portion 130a and the electrode 4 can be more reliably electrically connected. Details of these effects will be described in “2. Manufacturing method of physical quantity sensor” described later.

  In the physical quantity sensor 100, the drive spring portion 132 (beam portion 133) connected to the fixed portion 130 provided on the protruding portion 18 is positioned in the direction in which the protruding portion 18 protrudes from the protruding portion 18. . Therefore, for example, compared with the case where the drive spring part is located on the opposite side of the protruding part from the protruding part, the apparatus can be downsized.

  In the physical quantity sensor 100, the area of the fixed portion 130 provided on the protruding portion 18 is larger than the area of the protruding portion 18 in plan view. Therefore, for example, the bonding strength between the functional element 102 and the substrate 10 can be improved as compared with the case where the area of the fixing portion 130 is smaller than the area of the protruding portion 18 in plan view.

2. Manufacturing Method of Physical Quantity Sensor Next, a manufacturing method of the physical quantity sensor 100 according to the present embodiment will be described with reference to the drawings. FIG. 5 is a flowchart illustrating an example of a method for manufacturing the physical quantity sensor 100 according to the present embodiment. 6-11 is a figure which shows typically the manufacturing process of the physical quantity sensor 100 which concerns on this embodiment. 6A to 11A correspond to FIG. 6B to 11B correspond to FIG. FIGS. 6C to 11C correspond to FIG. 4 and are cross-sectional views taken along the line CC of FIGS. 6B to 11B, respectively.

  First, the recessed part 16 and the protrusion part 18 are formed in the board | substrate (1st board | substrate) 10a (S10). The recess 16 and the protrusion 18 are formed by multistage etching.

  Specifically, first, as shown in FIG. 6, a first resist R1 is formed on the first surface 12 of the substrate 10a. The substrate 10a is, for example, a glass substrate. The first resist R1 is, for example, a photoresist or a metal film such as Cr. For example, when the first resist R1 is a photoresist, the first resist R1 is formed by photolithography. When the first resist R1 is a metal film such as Cr, the first resist R1 is formed by forming a metal film by sputtering or the like and then patterning the metal film by photolithography and etching. The thickness of the first resist R1 is, for example, about 2 μm to 3 μm.

  Next, as shown in FIG. 7, the substrate 10a is etched (first etching) using the first resist R1 as a mask. Etching of the substrate 10a is performed by wet etching, for example. As the etchant, for example, hydrofluoric acid or the like can be used. The etching of the substrate 10a may be performed by dry etching. By etching the substrate 10a using the first resist R1 as a mask, the first recess 16a and the protrusion 18 are formed. The depth of the first recess 16a is, for example, about the same as the thickness of the first resist R1. After the first etching is performed, the first resist R1 is removed.

  Next, as shown in FIG. 8, a second resist R2 is formed. For example, the second resist R2 is formed in the same region as the first resist R1. The second resist R2 is a mask for etching the first recess 6a in the depth direction, and may be formed in a region different from the first resist R1 as long as it has the function. The second resist R2 is formed in the same manner as the first resist R1 described above. The thickness of the second resist R2 is, for example, about 2 μm to 3 μm.

  In the present embodiment, since the second resist R2 is formed on the protruding portion 18, for example, the second resist R2 is formed with higher accuracy than when the second resist is formed on an independent island-shaped post portion. The second resist R2 having a desired shape can be obtained.

  For example, when the second resist R2 is a metal layer such as Cr, the second resist R2 is formed by sputtering the metal film by the sputtering method or the like in the same manner as the first resist R1 described above, and then the photolithography is performed on the metal film. And patterning by etching. Specifically, the step of forming the second resist R2 (Cr layer) includes a step of forming a Cr layer on the entire upper surface of the substrate 10a, a step of applying a resist solution on the Cr layer, and a resist solution. After the photoresist is cured to form a photoresist layer, exposure and development are performed to pattern the photoresist layer, and a Cr layer is etched using the patterned photoresist layer as a mask.

  Here, since the protruding portion 18 protruding from the wall portion 17 is continuous with the other surface of the substrate 10, in the step of applying a resist solution on the Cr layer, for example, an independent island-shaped post portion. In comparison, the resist solution is less likely to aggregate. Therefore, the photoresist layer can be formed with high accuracy, and the second resist R2 can be formed in a desired shape.

  Next, as shown in FIG. 9, the substrate 10a is etched (second etching) using the second resist R2 as a mask. The second etching of the substrate 10a is performed in the same manner as the first etching described above.

  By the second etching, the bottom surface of the first recess 16a is further etched to form the second recess, and the recess 16 is obtained. At this time, as described above, the second resist R2 on the protruding portion 18 can be formed in a desired shape, so that a part (corner portion or the like) of the protruding portion 18 may be etched by the second etching. Can be reduced. After the second etching is performed, the second resist R2 is removed.

  Through the above steps, the recess 16 and the protrusion 18 are formed in the substrate 10a. The substrate 10 is obtained by forming the recess 16 and the protrusion 18 on the substrate 10a. Here, the case where the concave portion 16 and the protruding portion 18 are formed by two etchings of the first etching and the second etching has been described here, but the concave portion 16 and the protruding portion 18 may be formed by three or more etchings. Good.

  Next, as shown in FIG. 10, the wiring 6 and the electrode 4 are formed (S12).

  First, the groove 3 is formed on the protrusion 18. The groove 3 is formed by, for example, photolithography and etching.

  Next, the wiring 6 is formed in the groove 3, the side surface of the protrusion 18, and the bottom surface of the recess 16. The wiring 6 is formed by, for example, film formation by sputtering or CVD, and patterning. The patterning is performed by, for example, photolithography and etching. In this step, the fixed detection electrode portion 146 may be formed on the bottom surface of the recess 16 simultaneously with the wiring 6.

  Next, the electrode 4 is formed on the wiring 6. The electrode 4 is formed by film formation by sputtering or CVD, and patterning, similarly to the wiring 6 described above. In this step, the electrode 4 is formed so as to protrude from the upper surface 18a of the protrusion 18 (the first surface 12 of the substrate 10), as shown in FIG. That is, the electrode 4 is formed so that the sum of the thickness of the wiring 6 and the thickness of the electrode 4 is larger than the depth of the groove 3. Through the above steps, the wiring 6 and the electrode 4 can be formed.

  Next, as shown in FIG. 11, a silicon substrate (second substrate) 101 is bonded to the first surface 12 of the substrate 10 (S14). The bonding between the substrate 10 and the silicon substrate 101 is performed by, for example, anodic bonding. Thereby, the board | substrate 10 and the silicon substrate 101 can be joined firmly. In this step, as shown in FIG. 11C, when the upper surface 18a of the projecting portion 18 and the silicon substrate 101 are joined, the electrode 4 is crushed, so the silicon substrate 101 (fixed portion 130a) and the electrode 4 Can be reliably connected electrically.

  Next, as shown in FIGS. 1 to 4, the silicon substrate 101 is ground and thinned by, for example, a grinder, and then patterned into a predetermined shape to form the functional element 102 (S <b> 16). The patterning is performed by photolithography and etching (dry etching), and a Bosch method can be used as specific etching. At this time, since the area of the fixing portion 130a is formed larger than the area of the protruding portion 18 in a plan view, an allowable range of misalignment can be increased.

  Next, the substrate 10 and the lid 20 are joined, and the functional element 102 is accommodated in the cavity 2 formed by the substrate 10 and the lid 20 (S18). The bonding between the substrate 10 and the lid 20 is performed by, for example, anodic bonding. Thereby, the board | substrate 10 and the cover body 20 can be joined firmly.

  Through the above steps, the physical quantity sensor 100 can be manufactured.

  The manufacturing method of the physical quantity sensor 100 according to the present embodiment has the following features, for example.

  In the method of manufacturing the physical quantity sensor 100 according to the present embodiment, the substrate 10 is etched to form the recess 16 and the projecting portion 18 projecting from the wall portion 17 defining the recess 16 (S10), and the projecting portion 18. The step of bonding the silicon substrate 101 to the substrate (S14) and the step of etching the silicon substrate 101 to form the functional element 102 on the recess 16 (S16) are included. As described above, in this embodiment, since the silicon substrate 101 is bonded to the projecting portion 18, for example, compared with a case where a silicon substrate is bonded to an island-shaped post portion, a portion bonded to the functional element 102 of the substrate 10 ( The protrusion 18) can be formed in a desired shape, and the bonding strength between the functional element 102 and the substrate 10 can be improved.

  For example, when forming an island-like post portion independent on the substrate, the resist solution aggregates on the post portion due to surface tension or the like when performing multi-stage etching to form the recess, and etching to form the recess In this case, a part of the post portion (corner portion or the like) may be etched. For this reason, it is difficult to form the post portion in a desired shape. Therefore, the contact area between the fixed portion and the post portion is reduced, and the bonding strength between the functional element and the substrate may be reduced. On the other hand, as described above, since the protruding portion protruding from the wall portion is continuous with the other surface of the substrate, the resist solution is less likely to aggregate compared to the independent island-shaped post portion, It can be formed into a desired shape. Therefore, according to the present embodiment, the portion (projecting portion) to be bonded to the functional element of the substrate can be formed in a desired shape, and the bonding strength between the functional element 102 and the substrate 10 can be improved.

  The manufacturing method of the physical quantity sensor 100 according to the present embodiment includes a step (S12) of forming the wiring 6 and the electrode 4 on the protrusion 18. Therefore, according to the present embodiment, for example, the fixed portion 130a and the electrode 4 can be more reliably connected to each other than when the fixed portion is electrically connected to the electrode provided on the independent island-shaped post portion. Can be connected.

  As described above, it is difficult to form the post part in a desired shape. For example, if the corners of the post part are etched, a resist for patterning the electrode when forming the electrode on the post part. May not be formed in a desired shape, and a desired electrode may not be formed. Thereby, there is a possibility that the functional element and the electrode cannot be reliably electrically connected (for example, the resistance becomes high). On the other hand, in the present embodiment, since the protruding portion 18 can be formed in a desired shape, the fixed portion is electrically connected to the electrode provided on the independent island-shaped post portion and In comparison, the fixed portion 130a and the electrode 4 can be more reliably electrically connected.

3. Next, an electronic device according to the present embodiment will be described with reference to the drawings. FIG. 12 is a functional block diagram of the electronic apparatus 1000 according to the present embodiment.

  The electronic device 1000 includes a physical quantity sensor according to the present invention. Below, the case where the physical quantity sensor 100 is included as a physical quantity sensor which concerns on this invention is demonstrated.

  The electronic device 1000 further includes an arithmetic processing unit (CPU) 1020, an operation unit 1030, a ROM (Read Only Memory) 1040, a RAM (Random Access Memory) 1050, a communication unit 1060, and a display unit 1070. Note that the electronic device of the present embodiment may have a configuration in which some of the components (each unit) in FIG. 12 are omitted or changed, or other components are added.

  The arithmetic processing unit 1020 performs various types of calculation processing and control processing in accordance with programs stored in the ROM 1040 or the like. Specifically, the arithmetic processing device 1020 performs various processes according to the output signal of the physical quantity sensor 100 and the operation signal from the operation unit 1030, the process of controlling the communication unit 1060 to perform data communication with the external device, A process of transmitting a display signal for displaying various information on the display unit 1070 is performed.

  The operation unit 1030 is an input device including operation keys, button switches, and the like, and outputs an operation signal corresponding to an operation by the user to the arithmetic processing device 1020.

  The ROM 1040 stores programs, data, and the like for the arithmetic processing unit 1020 to perform various calculation processes and control processes.

  The RAM 1050 is used as a work area of the arithmetic processing unit 1020, and programs and data read from the ROM 1040, data input from the physical quantity sensor 100, data input from the operation unit 1030, and the arithmetic processing unit 1020 according to various programs. The result of the operation that has been executed is temporarily stored.

  The communication unit 1060 performs various controls for establishing data communication between the arithmetic processing device 1020 and an external device.

  The display unit 1070 is a display device configured by an LCD (Liquid Crystal Display) or the like, and displays various types of information based on a display signal input from the arithmetic processing device 1020. The display unit 1070 may be provided with a touch panel that functions as the operation unit 1030.

  Various electronic devices can be considered as such an electronic device 1000, for example, personal computers (for example, mobile personal computers, laptop personal computers, tablet personal computers), mobile terminals such as smartphones and mobile phones, Digital still cameras, inkjet discharge devices (for example, inkjet printers), storage area network devices such as routers and switches, local area network devices, mobile terminal base station devices, televisions, video cameras, video recorders, car navigation devices, Real-time clock device, pager, electronic organizer (including communication function), electronic dictionary, calculator, electronic game device, game controller, word processorー, workstation, videophone, TV monitor for crime prevention, electronic binoculars, POS terminal, medical equipment (eg electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish finder , Various measuring devices, instruments (for example, vehicles, aircraft, ships), flight simulators, head mounted displays, motion traces, motion tracking, motion controllers, PDR (pedestrian position direction measurement), and the like.

  FIG. 13 is a diagram illustrating an example of the appearance of a smartphone that is an example of the electronic apparatus 1000. A smartphone that is the electronic apparatus 1000 includes a button as the operation unit 1030 and an LCD as the display unit 1070.

  FIG. 14 is a diagram illustrating an example of an appearance of an arm-mounted portable device (wearable device) that is an example of the electronic device 1000. The wearable device that is the electronic device 1000 includes an LCD as the display unit 1070. The display unit 1070 may be provided with a touch panel that functions as the operation unit 1030.

  In addition, the mobile device that is the electronic device 1000 includes a position sensor such as a GPS receiver (GPS), and can measure the movement distance and movement locus of the user.

  Since the electronic device 1000 includes the physical quantity sensor 100 that can improve the bonding strength between the functional element and the substrate, the reliability can be improved.

4). Next, the moving body according to the present embodiment will be described with reference to the drawings. FIG. 15 is a perspective view schematically showing an automobile as the moving body 1100 according to the present embodiment.

  The mobile body according to the present embodiment includes the physical quantity sensor according to the present invention. Hereinafter, a moving object including the physical quantity sensor 100 will be described as a physical quantity sensor according to the present invention.

  The mobile body 1100 according to the present embodiment further includes a controller 1120 that performs various controls such as an engine system, a brake system, and a keyless entry system, a controller 1130, a controller 1140, a battery 1150, and a backup battery 1160. Yes. Note that the moving body 1100 according to this embodiment may omit or change some of the components (each unit) illustrated in FIG. 15 or may have a configuration in which other components are added.

  As such a moving body 1100, various moving bodies are conceivable, and examples thereof include automobiles (including electric automobiles), airplanes such as jets and helicopters, ships, rockets, and artificial satellites.

  Since the moving body 1100 includes the physical quantity sensor 100 that can improve the bonding strength between the functional element and the substrate, the reliability can be improved.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

2 ... cavity, 3 ... groove, 4 ... electrode, 6 ... wiring, 6a ... first recess, 10 ... substrate, 10a ... substrate, 12 ... first surface, 14 ... second surface, 16 ... recess, 16a ... first DESCRIPTION OF SYMBOLS 1 Recessed part, 17 ... Wall part, 18 ... Projection part, 18a ... Upper surface, 20 ... Cover body, 100 ... Physical quantity sensor, 101 ... Silicon substrate, 102 ... Functional element, 112 ... Structure, 112a ... First structure, 112b ... second structure 130 ... fixed part 130a ... fixed part 132 ... drive spring part 133 ... beam part 134 ... mass body 136 ... movable drive electrode part 138 ... fixed drive electrode part 139 ... fixed drive Electrode unit 140 ... movable body 142 ... beam portion 144 ... movable detection electrode unit 146 ... fixed detection electrode unit 1000 ... electronic device 1020 ... processing unit 1030 ... operation unit 1040 ... ROM 1050 ... RAM 1060 ... Shin part, 1070 ... the display unit, 1100 ... mobile, 1120 ... controller, 1130 ... controller, 1140 ... controller, 1150 ... battery, 1160 ... backup battery

Claims (8)

A substrate having a recess;
A functional element having a fixing portion fixed to the substrate;
Including
The substrate has a protruding portion protruding from a wall portion defining the concave portion,
The fixed part is a physical quantity sensor joined to the protruding part. In claim 1,
The fixed portion is a physical quantity sensor that is electrically connected to an electrode provided on the protruding portion. In claim 1 or 2,
The functional element has a spring portion connected to the fixed portion,
The physical quantity sensor, wherein the spring part is located in a direction in which the protruding part protrudes from the protruding part. In any one of Claims 1 thru | or 3,
The physical quantity sensor in which the area of the fixed portion is larger than the area of the protruding portion in plan view. Etching the first substrate to form a recess and a protrusion protruding from the wall defining the recess;
Bonding a second substrate to the protruding portion;
Etching the second substrate to form a functional element on the recess;
A method for manufacturing a physical quantity sensor, comprising: In claim 5,
A method of manufacturing a physical quantity sensor, comprising a step of forming an electrode on the protrusion.   An electronic device comprising the physical quantity sensor according to claim 1.   A moving body comprising the physical quantity sensor according to claim 1.