JP5292825B2 - Method for manufacturing mechanical quantity sensor - Google Patents

Description

  The present invention relates to a mechanical quantity sensor for detecting a mechanical quantity and a method for manufacturing the same.

A technique of a mechanical quantity sensor that detects an acceleration and an angular velocity configured by sandwiching a sensor structure made of a semiconductor between a pair of glass substrates and joining them by anodic bonding is disclosed (see Patent Document 1). In addition, in order to simplify the wiring inside the sensor, a technology for forming isolated wiring pillars in the silicon substrate, forming conductive parts where necessary for wiring, and electrically connecting the top and bottom of the substrate Is disclosed (see Patent Document 2).
JP 2002-350138 A JP 2007-3192 A, paragraph number 0108

However, when the second glass substrate is to be anodic bonded after anodic bonding to the first glass substrate in the production of the mechanical quantity sensor described above, the first glass substrate after bonding is electrically insulating material (or conductive). Therefore, a voltage cannot be appropriately applied to the bonding surface of the sensor structure with the second glass substrate via the first glass substrate, and the bonding to the second glass substrate is not possible. Defects occur. More specifically, there are examples in which the bonding strength necessary for vacuum sealing cannot be obtained between the second glass substrate and the semiconductor substrate, and examples in which the bonding is not performed at all, and the sensor structure and the second glass substrate. The reproducibility of processing was not obtained during the anodic bonding.
In particular, since the wiring columnar body in Patent Document 2 is electrically isolated in the silicon substrate, a voltage required for anodic bonding cannot be applied to the wiring columnar body. Then, as a result of earnest experiments, it was found that the above-described bonding failure occurred in the wiring columnar portion and a good electrical connection could not be obtained.

  Therefore, in view of the above, the present invention provides a mechanical quantity sensor capable of suppressing defects at a joint portion when the sensor structure is vacuum-sealed using the anodic bonding method as described above, and a method for manufacturing the same. In addition, an object of the present invention is to provide a mechanical quantity sensor and a method for manufacturing the same, in which joining and electrical connection are preferably performed by making the joining surface of the sensor structure substantially equipotential during anodic joining.

  A mechanical quantity sensor according to an aspect of the present invention connects a fixed portion having an opening, a displacement portion disposed in the opening and displaced with respect to the fixed portion, and the fixed portion and the displacement portion. A connecting portion; and a plurality of first block members that are not connected to any of the fixed portion, the displacement portion, and the connecting portion and that are spaced apart from each other, and are made of a first semiconductor material A plurality of first structures which are joined to the plurality of first block members and spaced apart from each other, a pedestal joined to the fixed part, a weight part joined to the displacement part, A second block member, and a second structure body made of an electrically conductive second semiconductor material and arranged in a stacked manner on the first structure body, and an insulating material, A joint for joining the first and second structures; A first base that is connected to a portion and stacked on the first structure, a second base that is connected to the pedestal and stacked on the second structure, and the third structure Penetrating through the body, penetrating through the first base or the second base with a plurality of first conductive parts electrically connecting the plurality of first and second block members, respectively, A plurality of first block members or a plurality of second conductive portions electrically connected to each of the plurality of second block members are provided.

  A method of manufacturing a mechanical quantity sensor according to one aspect of the present invention includes a first layer made of a first semiconductor material, a second layer made of an insulating material, and a second semiconductor material made of a conductive second material. From the first layer of the semiconductor substrate in which the three layers are sequentially stacked, a base having an opening, a weight part disposed in the opening, and not connected to any of the base and the weight part, And forming a first structure having a plurality of first block members spaced apart from each other, penetrating through the second layer, the plurality of first block members and the third block member. Forming a plurality of first conductive portions that electrically connect the layers, anodically bonding a first base made of an insulating material to the pedestal, and penetrating the first base , Electrically with each of the plurality of first block members A step of forming a plurality of second conducting portions to be continued; a fixing portion joined to the base from the third layer; a displacement portion connected to the weight portion; the fixing portion and the displacement A step of forming a second structure having a connecting portion for connecting a portion and a plurality of second block members connected to the plurality of first block members, and an insulating material. Joining the second base to the fixed portion.

  According to the present invention, when the sensor structure is vacuum-sealed by using the anodic bonding method, it is possible to suppress defects at the bonded portion, and the bonding surface of the sensor structure is substantially reduced during anodic bonding. By making them equipotential, bonding and electrical connection can be made preferable.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is an exploded perspective view showing a state in which a mechanical quantity sensor 100 according to an embodiment of the present invention is disassembled. The mechanical quantity sensor 100 includes a structure 110, a joint 120, a structure 130, a base 140, and a base 150 that are stacked on each other.

  FIG. 2 is an exploded perspective view illustrating a state in which a part (structure 110, structure 130) of the mechanical quantity sensor 100 is further disassembled. 3, 4, and 5 are top views of the structure 110, the joint 120, and the structure 130, respectively. 6, 7, and 8 are a bottom view of the base 150, a top view of the base 140, and a bottom view of the base 140, respectively. 9 and 10 are cross-sectional views showing a state in which the mechanical quantity sensor 100 is cut along BB and CC in FIG. In FIGS. 6 and 7, a block upper layer portion 114 and a block lower layer portion 134, which will be described later, are indicated by broken lines.

  The mechanical quantity sensor 100 functions as an electronic component by itself or in combination with a circuit board (for example, mounting on a board). The mechanical quantity sensor 100 as an electronic component can be mounted on a game machine, a mobile terminal (for example, a mobile phone) or the like. The mechanical quantity sensor 100 and the circuit board (an active element such as an IC on the circuit board, a wiring terminal) are electrically connected by wire bonding, flip chip, or the like.

  The mechanical quantity sensor 100 can measure one or both of the acceleration α and the angular velocity ω. That is, the mechanical quantity means one or both of acceleration α and angular velocity ω. By detecting the displacement of the displacement part 112 (described later) by the forces F0x, F0y, and F0z in the X, Y, and Z axis directions, the accelerations αx, αy, and αz can be measured. Further, by oscillating the displacement portion 112 in the Z-axis direction and detecting the displacement of the displacement portion 112 due to the Coriolis forces Fy and Fx in the Y and X-axis directions, the angular velocities ωx and ωy in the X and Y-axis directions are obtained. It can be measured. Thus, the mechanical quantity sensor 100 can measure the triaxial accelerations αx, αy, αz and the biaxial angular velocities ωx, ωy. Details of this will be described later.

The outer periphery of each of the structure 110, the joint 120, the structure 130, the base 150, and the base 140 is, for example, a substantially square shape with a side of 5 mm, and the heights thereof are, for example, 20 μm, 2 μm, 600 μm, and 500 μm, respectively. 500 μm.
The structure 110, the joint 120, and the structure 130 can be made of silicon, silicon oxide, and silicon, respectively, and the mechanical quantity sensor 100 is an SOI (Silicon On Insulator) having a three-layer structure of silicon / silicon oxide / silicon. It can be manufactured using a substrate. It is preferable to use a conductive material that contains impurities such as boron as a whole for silicon constituting the structure 110 and the structure 130. As will be described later, the wiring of the mechanical quantity sensor 100 can be simplified by configuring the structure 110 and the structure 130 with silicon containing impurities. In this embodiment mode, silicon containing impurities is used for the structure 110 and the structure 130.
Further, each of the base 140 and the base 150 can be made of a glass material containing movable ions. The reason why the glass contains mobile ions is because of later anodic bonding.

  The structure 110 has a substantially square outer shape, and includes a fixed portion 111 (111a to 111c), a displacement portion 112 (112a to 112e), a connection portion 113 (113a to 113d), and a block upper layer portion (block member) 114 (114a to 114a). 114j). The structure 110 can be formed by etching the semiconductor material film to form the openings 115a to 115d and the block upper layer portions 114a to 114j.

  The fixed part 111 can be divided into a frame part 111a and projecting parts 111b and 111c. The frame portion 111a is a frame-shaped substrate whose outer periphery and inner periphery are both substantially square. The protruding portion 111b is disposed at a corner portion on the inner periphery of the frame portion 111a, and protrudes toward the displacement portion 112b (when the X direction of the XY plane is 0 °, the 0 ° direction). It is. The protruding portion 111c is disposed at the corner portion on the inner periphery of the frame portion 111a, and protrudes toward the displacing portion 112d (in the 180 ° direction when the X direction of the XY plane is 0 °). It is. The frame portion 111a and the protruding portions 111b and 111c are integrally configured.

  The displacement part 112 is comprised from the displacement parts 112a-112e. The displacement part 112 a is a substrate having a substantially square outer periphery, and is disposed in the vicinity of the center of the opening of the fixed part 111. The displacement portions 112b to 112e are substrates having a substantially square outer periphery, and are connected and arranged so as to surround the displacement portion 112a from four directions (X-axis positive direction, X-axis negative direction, Y-axis positive direction, and Y-axis negative direction). Is done. The displacement parts 112 a to 112 e are joined to weight parts 132 a to 132 e described later by the joint part 120 and displaced integrally with the fixed part 111.

  The upper surface of the displacement portion 112a functions as a drive electrode E1 (described later). The driving electrode E1 on the upper surface of the displacement portion 112a is capacitively coupled to a driving electrode 154a, which will be described later, installed on the lower surface of the base 150, and the displacement portion 112 is vibrated in the Z-axis direction by a voltage applied therebetween. . Details of this drive will be described later.

  The upper surfaces of the displacement portions 112b to 112e function as detection electrodes E1 (described later) that detect displacement of the displacement portion 112 in the X-axis and Y-axis directions. The detection electrodes on the upper surfaces of the displacement portions 112b to 112e are capacitively coupled to detection electrodes 154b to 154e, which will be described later, installed on the lower surface of the base 150 (the alphabets b to e of the displacement portion 112 and the detection electrodes). The alphabets b to e of the electrode 154 correspond to each other in order). Details of this detection will be described later.

  The connection portions 113a to 113d are substantially rectangular substrates, and the fixed portion 111 and the displacement portion 112a are arranged in four directions (45 °, 135 °, 225 °, 315 ° when the X direction of the XY plane is 0 °). Direction).

  The connecting portions 113a to 113d are joined to a projecting portion 131c (described later) of the pedestal 131 by a joining portion 120 in a region near the frame portion 111a. In the other regions of the connection portions 113a to 113d, that is, the region closer to the displacement portion 112a, the protrusion 131c is not formed in the corresponding region, and the thickness is small, so that the region has flexibility. The reason why the regions of the connecting portions 113a to 113d near the frame portion 111a are joined to the protruding portion 131c is to prevent the connecting portions 113a to 113d from being damaged by a large deflection.

  The connecting portions 113a to 113d function as beams that can be bent. As the connecting portions 113a to 113d are bent, the displacement portion 112 can be displaced with respect to the fixed portion 111. Specifically, the displacement portion 112 is linearly displaced in the Z positive direction and the Z negative direction with respect to the fixed portion 111. Further, the displacement portion 112 can rotate positively and negatively with respect to the fixed portion 111 with the X axis and the Y axis as rotation axes. That is, the “displacement” here can include both movement and rotation (movement in the Z-axis direction, rotation in the X and Y axes).

  The block upper layer portion (block member) 114 includes block upper layer portions 114a to 114j. The block upper layer portions 114a to 114j are substantially square substrates, and are arranged along the inner periphery of the fixed portion 111 so as to surround the displacement portion 112 from the periphery. The block upper layer portions 114a to 114j correspond to a plurality of first block members spaced apart from each other.

  The block upper layer portions 114h and 114a have end surfaces that face the end surfaces of the displacement portions 112e, the block upper layer portions 114b and 114c have end surfaces that face the end surfaces of the displacement portions 112b, and the block upper layer portions 114d and 114e The block upper layer portions 114f and 114g have end surfaces that face the end surfaces of the displacement portion 112c. As shown in FIG. 1, each of the block upper layer portions 114 a to 114 h has an end surface that faces one of the eight end surfaces of the displacement portion 112 and is arranged clockwise in alphabetical order. The block upper layer portion 114i and the block upper layer portion 114j are arranged in directions of 90 ° and 270 °, respectively, where the X direction of the XY plane is 0 °.

  The block upper layer portions 114a to 114h are respectively joined to block lower layer portions 134a to 134h described later by the joint portion 120 (the alphabets a to h of the block upper layer portion 114 and the alphabets a to h of the block lower layer portion 134 are Each corresponds in turn).

  The block upper layer portions 114i and 114j are respectively joined to the block lower layer portions 134i and 134j, which will be described later, by the joint portion 120, and are used for the purpose of wiring for vibrating the displacement portion 112 in the Z-axis direction. Details of this will be described later.

The structure 130 has a substantially square outer shape, and includes a pedestal 131 (131a to 131d), a weight part 132 (132a to 132e), and a block lower layer part (block member) 134 (134a to 134j). The structure 130 can be created by etching a semiconductor material substrate to form openings 133, block lower layer portions 134a to 134j, and pockets 135 (described later).
The pedestal 131 and the block lower layer portions 134a to 134j are substantially equal in height to each other, and the weight portion 132 is lower in height than the pedestal 131 and the block lower layer portions 134a to 134j. This is because a gap (gap) is ensured between the weight part 132 and the base body 140 and the weight part 132 can be displaced. The pedestal 131, the block lower layer portions 134a to 134j, and the weight portion 132 are arranged separately from each other.

The pedestal 131 can be divided into a frame part 131a and projecting parts 131b to 131d.
The frame portion 131 a is a frame-shaped substrate having both an outer periphery and an inner periphery that are substantially square, and has a shape corresponding to the frame portion 111 a of the fixed portion 111.
The protruding portion 131b is disposed at a corner portion on the inner periphery of the frame portion 131a, and protrudes toward the weight portion 132b (when the X direction of the XY plane is 0 °, the 0 ° direction). And has a shape corresponding to the protruding portion 111b of the fixed portion 111.

  The projecting portions 131c are four substantially rectangular substrates. When the X direction of the XY plane is 0 °, the projecting portions 131c are directed from the frame portion 131a to the weight portion 132a in 45 °, 135 °, 225 °, and 315 ° directions. And one end connected to the frame portion 131a of the pedestal 131 and the other end spaced apart from the weight portion 132a. The protruding portion 131c is formed in a substantially half region on the frame portion 131a side among the regions corresponding to the connection portions 113a to 113d, and is formed in another region, that is, a substantially half region on the weight portion 132 side. It has not been.

  The protruding portion 131d is disposed at a corner portion on the inner periphery of the frame portion 131a, and protrudes toward the weight portion 132d (when the X direction of the XY plane is 0 °, the 180 ° direction). Inside, a pocket 135 (opening) penetrating the front and back surfaces of the substrate is formed, and is joined to the protruding portion 111c of the fixed portion 111.

  The pocket 135 is, for example, a rectangular parallelepiped space in which a getter material for maintaining a high vacuum is placed. One open end of the pocket 135 is covered with a joint 120. The other open end of the pocket 135 is mostly covered by the base 140, but a portion near the weight portion 132 is not covered, and the other open end and the weight portion 132 are formed. The opening 133 is partially communicated (not shown). The getter material adsorbs residual gas for the purpose of increasing the degree of vacuum in the mechanical quantity sensor 100 sealed in vacuum, and can be made of, for example, an alloy containing zirconium as a main component.

The frame portion 131a and the protruding portions 131b to 131d are integrally configured.
The pedestal 131 is connected to the fixed portion 111 and predetermined regions of the connection portions 113a to 113d by the joint portion 120.

  The weight part 132 has a mass and functions as a weight or an action body that receives the force F0 and the Coriolis force F caused by the acceleration α and the angular velocity ω, respectively. That is, when acceleration α and angular velocity ω are applied, force F 0 and Coriolis force F act on the center of gravity of the weight portion 132.

  The weight part 132 is divided into substantially rectangular parallelepiped weight parts 132a to 132e. The weight parts 132b to 132e are connected to the weight part 132a arranged at the center from four directions, and can be displaced (moved and rotated) integrally as a whole. That is, the weight part 132a functions as a connection part for connecting the weight parts 132b to 132e.

  Each of the weight portions 132a to 132e has a substantially square cross-sectional shape corresponding to the displacement portions 112a to 112e, and is joined to the displacement portions 112a to 112e by the joining portion 120. The displacement portion 112 is displaced according to the force F0 and the Coriolis force F applied to the weight portion 132, and as a result, the acceleration α and the angular velocity ω can be measured.

  The back surface of the weight portion 132a functions as a drive electrode E1 (described later). The driving electrode E1 on the back surface of the weight portion 132a is capacitively coupled to a driving electrode 144a, which will be described later, installed on the upper surface of the base 140, and the displacement portion 112 is vibrated in the Z-axis direction by a voltage applied therebetween. . Details of this drive will be described later.

  The back surfaces of the weight portions 132b to 132e function as detection electrodes E1 (described later) that detect displacement of the displacement portion 112 in the X-axis and Y-axis directions. The detection electrodes E1 on the back surfaces of the weight parts 132b to 132e are capacitively coupled to detection electrodes 144b to 144e, which will be described later, installed on the upper surface of the base 140 (the alphabets b to e of the weight part 132 are detected). The alphabets b to e of the electrode 144 correspond to each other in order). Details of this detection will be described later.

  The block lower layer portions (block members) 134a to 134j have substantially square cross-sectional shapes corresponding to the block upper layer portions 114a to 114j, respectively, and are joined to the block upper layer portions 114a to 114j by the joint portion 120. The block lower layer portions 134a to 134j correspond to a plurality of second block members each having a shape corresponding to the plurality of first block members.

  The blocks obtained by joining the block upper layer portions 114a to 114j and the block lower layer portions 134a to 134j are hereinafter referred to as “blocks a to j”, respectively. The blocks a to h are used for wiring for supplying power to the driving electrodes 154b to 154e and 144b to 144e, respectively. The blocks i and j are used for the purpose of wiring for vibrating the displacement portion 112 in the Z-axis direction. At the time of anodic bonding of the structure 110 and the base body 150, all of the blocks a to j are substantially equipotential with the fixed portion 111, so that problems during anodic bonding can be reduced. Details of these will be described later.

The joint 120 connects the structures 110 and 130 as described above. The joining portion 120 includes a joining portion 121 that connects a predetermined region of the connecting portion 113 and the fixing portion 111 and the pedestal 131, and a joining portion 122 (122a to 122e that connects the displacement portions 112a to 112e and the weight portions 132a to 133e. ) And the joint 123 (123a to 123j) connecting the block upper layer portions 114a to 114j and the block lower layer portions 134a to 134j. The joint 120 is not connected to the structures 110 and 130 at other portions. This is because the connecting portions 113a to 113d can be bent and the weight portion 132 can be displaced.
The junctions 121, 122, and 123 can be configured by etching a silicon oxide film.

  Conducting portions 160 to 163 are formed in order to connect the structure 110 and the structure 130 at necessary portions.

The conducting part 160 conducts the fixed part 111 and the pedestal 131, and penetrates the protruding part 111 b and the joining part 121 of the fixed part 111.
The conducting part 161 conducts the displacement part 112 and the weight part 132, and penetrates the displacement part 112 a and the joint part 122.

  The conduction part 162 conducts the block upper layer parts 114a, 114b, 114e, 114f, 114i and the block lower layer parts 134a, 134b, 134e, 134f, 134i, respectively, and the block upper layer parts 114a, 114b, 114e, 114f, 114i and the joint 123 are respectively penetrated. The conductive portion 162 electrically connects wiring layers L1, L4, L5, L6, and L7, which will be described later, and wiring terminals T10, T3, T6, T7, and T2. That is, the conduction part 162 is used when the mechanical quantity sensor 100 is operated.

  The conduction portion 163 conducts the block upper layer portions 114c, 114d, 114g, 114h, 114j and the block lower layer portions 134c, 134d, 134g, 134h, 134j, respectively, and the block upper layer portions 114c, 114d, 114g, 114h, 114j and the joint 123 are respectively penetrated. The conducting portion 163 is used for applying a voltage to the structure 110 when the structure 110 and the base 150 are anodically joined, and contributes to a reduction in defects during the anodic joining.

  For example, the conductive portions 160 to 163 are formed by forming a metal layer such as Al on the edge, wall surface, and bottom of the through hole. The shape of the through hole is not particularly limited, but it is preferable that the through holes of the conductive portions 160 to 163 have a wide cone shape because the metal layer can be effectively formed by sputtering such as Al.

The base 140 is made of a glass material containing movable ions such as Pyrex (registered trademark) glass, and has a substantially square substrate shape.
The structure 130 other than the weight part 132, that is, the base 131 and the block lower layer parts 134a to 134j are joined to the base 140 by anodic bonding. The weight part 132 is not joined to the base 140 because the height is lower than the base 131 and the block lower layer parts 134a to 134j. This is because a gap (gap) is ensured between the weight part 132 and the base body 140 and the weight part 132 can be displaced.
The base body 140 may be an insulating substrate in which the conical through holes 11 are formed at predetermined positions, and an insulating substrate such as a polyimide resin may be used. In this case, bonding can be performed by applying an adhesive and pressurizing and bonding or eutectic bonding.

  On the upper surface of the base 140, a driving electrode 144a and detection electrodes 144b to 144e are arranged so as to face the weight portion 132. The drive electrode 144a and the detection electrodes 144b to 144e can be made of a conductive material. The driving electrode 144a has, for example, a cross shape and is formed in the vicinity of the center of the upper surface of the base 140 so as to face the weight portion 132a. Each of the detection electrodes 144b to 144e is substantially square, and surrounds the drive electrode 144a from four directions (X-axis positive direction, X-axis negative direction, Y-axis positive direction, and Y-axis negative direction). It is arranged to face 132e. The drive electrode 144a and the detection electrodes 144b to 144e are separated from each other.

A wiring layer L2 that is electrically connected to the back surface of the block lower layer part 134j is connected to the driving electrode 144a.
The detection electrode 144b has a wiring layer L8 that is electrically connected to the back surface of the block lower layer portion 134c, and the detection electrode 144c has a wiring layer L9 that is electrically connected to the back surface of the block lower layer portion 134d. A wiring layer L10 electrically connected to the back surface of the block lower layer part 134g is connected to the electrode 144d, and a wiring layer L11 electrically connected to the back surface of the block lower layer part 134h is connected to the detection electrode 144e. Yes.

  The base 140 is provided with wiring terminals T (T1 to T11) penetrating the base 140, and from the outside of the mechanical quantity sensor 100 to the drive electrodes 154a and 144a, the detection electrodes 154b to 154e, and 144b to 144e. This enables electrical connection.

  The upper end of the wiring terminal T1 is connected to the back surface of the protrusion 131b of the base 131. The wiring terminals T2 to T9 are connected to the back surfaces of the block lower layer portions 134a to 134h, respectively (the numbers T2 to T9 of the wiring terminals T2 to T9 and the alphabets 134a to 134h of the block lower layer portions 134a to 134h). The order corresponds to each). The wiring terminals T10 and T11 are connected to the back surfaces of the block lower layer portions 134i and 134j, respectively.

  As shown in FIGS. 9 and 10, the wiring terminal T is formed by, for example, forming a metal film such as Al on the edge, wall surface, and bottom of the wide conical through hole. It has the same structure as 162. The wiring terminal T can be used as a connection terminal for connecting to an external circuit by, for example, wire bonding.

  The base 150 is made of a glass material containing movable ions such as Pyrex (registered trademark) glass, has a substantially rectangular parallelepiped outer shape, and has a frame portion 151 and a bottom plate portion 152. The frame portion 151 and the bottom plate portion 152 can be formed by forming a concave portion 153 having a substantially rectangular parallelepiped shape (for example, vertical and horizontal 2.5 mm, depth 5 μm) so that the displacement portion can be displaced on the substrate.

The frame portion 151 has a frame-like substrate shape in which the outer periphery and the inner periphery are both substantially square. The outer periphery of the frame part 151 coincides with the outer periphery of the fixed part 111, and the inner periphery of the frame part 151 is smaller than the inner periphery of the fixed part 111.
The bottom plate portion 152 has a substantially square substrate shape whose outer periphery is substantially the same as the frame portion 151.
The reason why the concave portion 153 is formed in the base 150 is to ensure a space for the displacement portion 112 to be displaced. The structure 110 other than the displacement portion 112, that is, the fixed portion 111 and the block upper layer portions 114a to 114j are joined to the base 150 by anodic bonding.

  On the bottom plate portion 152 (on the back surface of the base 150), a driving electrode 154a and detection electrodes 154b to 154e are disposed so as to face the displacement portion 112. Both the driving electrode 154a and the detection electrodes 154b to 154e can be made of a conductive material. The driving electrode 154a has, for example, a cross shape and is formed near the center of the recess 153 so as to face the displacement portion 112a. Each of the detection electrodes 154b to 154e is substantially square, and surrounds the drive electrode 154a from four directions (X-axis positive direction, X-axis negative direction, Y-axis positive direction, and Y-axis negative direction). It is arranged to face 112e. The drive electrode 154a and the detection electrodes 154b to 154e are separated from each other.

  A wiring layer L1 electrically connected to the upper surface of the block upper layer portion 114i is connected to the driving electrode 154a. The detection electrode 154b has a wiring layer L4 electrically connected to the upper surface of the block upper layer portion 114b, and the detection electrode 154c has a wiring layer L5 electrically connected to the upper surface of the block upper layer portion 114e. A wiring layer L6 electrically connected to the upper surface of the block upper layer portion 114f is connected to the electrode 154d, and a wiring layer L7 electrically connected to the upper surface of the block upper layer portion 114a is connected to the detection electrode 154e. Yes.

  In FIG. 1 to FIG. 10, the base 140 is illustrated below in consideration of the visibility of the structure 110, the joint 120, and the structure 130. When the wiring terminal T and the external circuit are connected by, for example, wire bonding, the base 140 of the mechanical quantity sensor 100 can be easily connected by being disposed, for example.

(Operation and wiring of mechanical quantity sensor 100)
The wiring and electrodes of the mechanical quantity sensor 100 will be described.
13 is a cross-sectional view showing six sets of capacitive elements in the mechanical quantity sensor 100 shown in FIG. In FIG. 13, the portion that functions as an electrode is indicated by hatching. Although six sets of capacitive elements are illustrated in FIG. 13, ten sets of capacitive elements are formed in the mechanical quantity sensor 100 as described above.
One electrode of the 10 sets of capacitive elements is a drive electrode 154a and detection electrodes 154b to 154e formed on the base 150, and a drive electrode 144a and detection electrodes 144b to 144e formed on the base 140.
The other electrodes are the driving electrode E1 on the upper surface of the displacement portion 112a, the detection electrode E1 formed on the upper surface of the displacement portions 112b to 112e, and the driving electrode E1 and the weight portion 132b on the lower surface of the weight portion 132a. It is the electrode E1 for a detection formed in the lower surface of 132e, respectively. That is, the block in which the displacement portion 112 and the weight portion 132 are joined functions as a common electrode for 10 capacitive couplings. Since the structure body 110 and the structure body 130 are made of a conductive material (silicon containing impurities), the block in which the displacement portion 112 and the weight portion 132 are joined can function as an electrode.

  Since the capacitance of the capacitor is inversely proportional to the distance between the electrodes, it is assumed that the driving electrode E1 and the detection electrode E1 are on the upper surface of the displacement portion 112 and the lower surface of the weight portion 132. That is, the drive electrode E1 and the detection electrode E1 are not formed separately on the upper surface of the displacement portion 112 or the surface layer of the lower surface of the weight portion 132. It is assumed that the upper surface of the displacement portion 112 and the lower surface of the weight portion 132 function as the drive electrode E1 and the detection electrode E1.

  The drive electrode 154a and the detection electrodes 154b to 154e formed on the base 150 are electrically connected to the block upper layer portions 114i, 114b, 114e, 114f, and 114a through the wiring layers L1 and L4 to L7, respectively. ing. Further, the block upper layer portions 114i, 114b, 114e, 114f, and 114a and the block lower layer portions 134i, 134b, 134e, 134f, and 134a are electrically connected to each other by the conductive portion 162.

  As shown in FIG. 6, the wiring layers L1, L4 to L7 include a first member (stepping portion) arranged between the block upper layer portion 114 and the base 140, and the first member. It can be considered that the second member is connected to the drive electrode 154a and the like. FIG. 11 is a plan view showing an enlarged state of the detection electrode 144b, the wiring layer L4, and the block upper layer portion 114b of FIG. The wiring layer L4 is divided into a first member L4a and a second member L4b. The boundary between the first and second members L4a and L4b is arranged outside the upper surface of the block upper layer portion 114b so that the electrical connection between the first member L4a and the block upper layer portion 114b is good.

  The drive electrode 144a and the detection electrodes 144b to 144e formed on the base 140 are electrically connected to the block lower layer portions 134j, 134c, 134d, 134g, and 134h through the wiring layers L2 and L8 to L11, respectively. ing.

  As shown in FIG. 7, the wiring layers L2, L8 to L11 include a first member (stepping portion) disposed between the block lower layer portion 134 and the base 150, and the first member It can be considered that the second member is connected to the drive electrode 154a and the like. FIG. 12 is a plan view showing an enlarged state of the detection electrode 154d, the wiring layer L10, and the block lower layer part 134g of FIG. The wiring layer L10 is divided into a first member L10a and a second member L10b. The boundary between the first and second members L10a and L10b is arranged outside the bottom surface of the block lower layer portion 134g so that the electrical connection between the first member L10a and the block upper layer portion 134g is good.

  Therefore, the wirings for the drive electrodes 154a and 144a and the detection electrodes 154b to 154e and 144b to 144e may be connected to the lower surfaces of the block lower layer portions 134a to 134j. The wiring terminals T2 to T9 are disposed on the lower surfaces of the block lower layer portions 134a to 134h, respectively, and the wiring terminals T10 and T11 are disposed on the lower surfaces of the block lower layer portions 134i and 134j, respectively.

  As described above, the wiring terminals T2 to T11 are electrically connected to the detection electrodes 154e, 154b, 144b, 144c, 154c, 154d, 144d, 144e, and the driving electrodes 154a, 144a, respectively, in order.

  The driving electrode E1 and the detection electrode E1 are formed from the upper surface of the displacement portion 112 and the lower surface of the weight portion 132, respectively. The displacement part 112 and the weight part 132 are electrically connected by a conduction part 161, both of which are made of a conductive material. The pedestal 131 and the fixed part 111 are electrically connected by a conductive part 160, both of which are made of a conductive material. The displacement part 112, the connection part 113, and the fixing part 111 are integrally formed of a conductive material. Therefore, the wiring for the drive electrode E1 and the detection electrode E1 may be connected to the lower surface of the pedestal 131. The wiring terminal T1 is disposed on the lower surface of the projecting portion 131b of the base 131, and the wiring terminal T1 is electrically connected to the driving electrode E1 and the detection electrode E1.

  As described above, since the structure 110 and the structure 130 are made of a conductive material (silicon containing impurities), the block in which the block upper layer portions 114a to 114j and the block lower layer portions 134a to 134j are joined. a to j can have a function as wiring, and wiring for the capacitor can be simplified.

The principle of acceleration and angular velocity detection by the mechanical quantity sensor 100 will be described.
(1) Vibration of the displacement portion 112 When a voltage is applied between the drive electrodes 154a and E1, the drive electrodes 154a and E1 are attracted to each other by the Coulomb force, and the displacement portion 112 (also the weight portion 132) is displaced in the positive direction of the Z axis. To do. When a voltage is applied between the drive electrodes 144a and E1, the drive electrodes 144a and E1 are attracted to each other by the Coulomb force, and the displacement portion 112 (also the weight portion 132) is displaced in the Z-axis negative direction. That is, by alternately applying a voltage between the drive electrodes 154a and E1 and between the drive electrodes 144a and E1, the displacement portion 112 (also the weight portion 132) vibrates in the Z-axis direction. The voltage can be applied using a positive or negative DC waveform (a pulse waveform when considering non-application), a half-wave waveform, or the like.

  The drive electrodes 154a and E1 (upper surface of the displacement portion 112a) and the drive electrodes 144a and E1 (lower surface of the weight portion 132a) serve as vibration applying portions, and the detection electrodes 154b to 154e, 144b to 144e, and E1 (displacement portion). The upper surfaces of 112b to 112e and the lower surfaces of the weight portions 132b to 132e function as displacement detection units.

  The period of vibration of the displacement part 112 is determined by the period at which the voltage is switched. The switching cycle is preferably close to the natural frequency of the displacement portion 112 to some extent. The natural frequency of the displacement portion 112 is determined by the elastic force of the connection portion 113, the mass of the weight portion 132, and the like. If the period of vibration applied to the displacement portion 112 does not correspond to the natural frequency, the energy of vibration applied to the displacement portion 112 is diverged and energy efficiency is reduced.

  Note that an AC voltage having a frequency that is ½ of the natural frequency of the displacement portion 212 may be applied only between the driving electrodes 154a and E1 or between the driving electrodes 144a and E1.

(2) Generation of Force Due to Acceleration When an acceleration α is applied to the weight part 132 (displacement part 112), a force F0 acts on the weight part 132. Specifically, the forces F0x (= m · αx), F0y (= m · αy), F0z in the X, Y, and Z axis directions according to the accelerations αx, αy, and αz in the X, Y, and Z axis directions, respectively. (= M · αz) acts on the weight part 132 (m is the mass of the weight part 132). As a result, the displacement portion 112 is inclined in the X and Y directions and displaced in the Z direction. In this way, the displacements 112 are inclined (displaced) in the X, Y, and Z directions by the accelerations αx, αy, and αz.

(3) Generation of Coriolis force due to angular velocity When the angular velocity ω is applied when the weight portion 132 (displacement portion 112) is moving in the Z-axis direction at the velocity vz, the Coriolis force F acts on the weight portion 132. . Specifically, according to the angular velocity ωx in the X-axis direction and the angular velocity ωy in the Y-axis direction, the Coriolis force Fy (= 2 · m · vz · ωx) in the Y-axis direction and the Coriolis force Fx (= 2 · m · vz · ωy) acts on the weight part 132 (m is the mass of the weight part 132).

  When the Coriolis force Fy due to the angular velocity ωx in the X-axis direction is applied, the displacement portion 112 is inclined in the Y direction. In this way, the displacement portion 112 is inclined (displaced) in the Y direction and the X direction by the Coriolis forces Fy and Fx caused by the angular velocities ωx and ωy.

(4) Detection of Displacement of Displacement Unit 112 As described above, the displacement (tilt) of the displacement unit 112 is generated by the acceleration α and the angular velocity ω. The displacement of the displacement portion 112 can be detected by the detection electrodes 154b to 154e and 144b to 144e.

  When a positive Z-direction force F0z is applied to the displacement portion 112, the distances between the detection electrodes E1 (upper surface of the displacement portion 112c) and 154c and between the detection electrodes E1 (upper surface of the displacement portion 112e) and 154e are both small. Become. As a result, the capacitance between the detection electrode E1 (upper surface of the displacement portion 112c) and 154c and between the detection electrode E1 (upper surface of the displacement portion 112e) and 154e is increased. That is, based on the sum of the capacitance between the detection electrode E1 and the detection electrodes 154b to 154e (or the sum of the capacitance between the detection electrode E1 and the detection electrodes 144b to 144e), the displacement of the displacement portion 112 in the Z direction is changed. Can be detected and extracted as a detection signal.

  On the other hand, when a positive Y-direction force F0y or Coriolis force Fy is applied to the displacement portion 112, the drive electrode E1 (upper surface of the displacement portion 112c) and 154c, the detection electrode E1 (lower surface of the weight portion 132e), 144e The distance between the detection electrodes E1 (the upper surface of the displacement portion 112e) and 154e, and the distance between the detection electrodes E1 (the lower surface of the weight portion 132c) and 144c increase. As a result, the capacitance between the detection electrode E1 (upper surface of the displacement portion 112c) and 154c, the detection electrode E1 (lower surface of the weight portion 132e), and 144e increases, and the detection electrode E1 (upper surface of the displacement portion 112e), Between 154e, the capacitance between the detection electrode E1 (the lower surface of the weight portion 132c) and 144c decreases. That is, based on the difference in capacitance between the detection electrode E1 and the detection electrodes 154b to 154e and 144b to 144e, a change in the inclination of the displacement portion 112 in the X and Y directions can be detected and taken out as a detection signal. it can.

  As described above, the detection electrodes E1, 154b to 154e and 144b to 144e detect the inclination of the displacement portion 112 in the X direction and the Y direction and the displacement in the Z direction.

(5) Extraction of acceleration and angular velocity from detection signal In the signals output from the detection electrodes 154b to 154e, 144b to 144e, E1, both components due to acceleration αx, αy, αz, angular velocity ωx, ωy are included. included. By using the difference between these components, the acceleration and angular velocity can be extracted.

  The force Fα (= m · α) when the acceleration α is applied to the weight part 132 (mass m) does not depend on the vibration of the weight part 132. That is, the acceleration component in the detection signal is a kind of bias component that does not correspond to the vibration of the weight portion 132. On the other hand, the force Fω (= 2 · m · vz · ω) when the angular velocity ω is applied to the weight part 132 (mass m) depends on the velocity vz of the weight part 132 in the Z-axis direction. That is, the angular velocity component in the detection signal is a kind of amplitude component that periodically changes corresponding to the vibration of the weight portion 132.

  Specifically, a bias component (acceleration) having a lower frequency than the frequency of the displacement unit 112 and a vibration component (angular velocity) similar to the frequency of the displacement unit 112 are extracted by frequency analysis of the detection signal. As a result, the mechanical quantity sensor 100 can measure the accelerations αx, αy, αz in the X, Y, and Z directions (three axes) and the angular velocities ωx, ωy in the X, Y directions (two axes).

(Creation of mechanical quantity sensor 100)
The production process of the mechanical quantity sensor 100 will be described.
FIG. 14 is a flowchart showing an example of a procedure for creating the mechanical quantity sensor 100. 15A to 15J are cross-sectional views showing the state of the mechanical quantity sensor 100 in the creation procedure of FIG. 14 (corresponding to a cross section obtained by cutting the mechanical quantity sensor 100 shown in FIG. 1 with CC). FIGS. 15A to 15J correspond to the mechanical quantity sensor 100 of FIG. 10 arranged upside down.

(1) Preparation of semiconductor substrate W (step S10 and FIG. 15A)
As shown in FIG. 15A, a semiconductor substrate W is prepared by laminating three layers of first, second and third layers 11, 12 and 13.

The first, second, and third layers 11, 12, and 13 are layers for forming the structure 110, the junction 120, and the structure 130, respectively. Here, silicon containing impurities, silicon oxide, A layer made of silicon containing impurities is used.
A semiconductor substrate W having a three-layer structure of silicon containing impurities / silicon oxide / silicon containing impurities includes a substrate in which a silicon oxide film is laminated on a silicon substrate containing impurities, and silicon containing impurities. After bonding the substrate, the silicon substrate containing the latter impurity is thinly polished (so-called SOI substrate).

Here, the silicon substrate containing impurities can be manufactured by doping impurities in the manufacture of a silicon single crystal by the Czochralski method, for example.
An example of impurities contained in silicon is boron. As silicon containing boron, for example, silicon containing high-concentration boron and having a resistivity of 0.001 to 0.01 Ω · cm can be used.

  Here, the first layer 11 and the third layer 13 are made of the same material (silicon containing impurities), but the first, second, and third layers 11, 12, and 13 All may be composed of different materials.

(2) Creation of structure 130 (etching of third layer 13, step S11, and FIGS. 15B and 15C)
The structure 130 is formed in the following manners a and b.
a. Formation of gap 10 (FIG. 15B)
A resist layer is formed on the upper surface of the third layer 13 except for the formation region of the weight portion 132 and the vicinity thereof, and the exposed portion (the formation region of the weight portion 132 and the vicinity thereof) not covered with the resist layer is perpendicular. Erosion downwards. As a result, the gap 10 for enabling the displacement of the weight portion 132 is formed above the region where the weight portion is formed.

b. Formation of structure 130 (FIG. 15C)
By etching the third layer 13 in which the gap 10 is formed, the opening 133, the block lower layer portions 134a to 134j, and the pocket 135 are formed, and the structure 130 is formed. That is, the thickness of a predetermined region (opening 133) of the third layer 13 is determined by an etching method that is erosive to the third layer 13 and not erodible to the second layer 12. Etching in the direction.

A resist layer having a pattern corresponding to the structure 130 is formed on the upper surface of the third layer 13, and the exposed portion not covered with the resist layer is eroded vertically downward.
FIG. 15C shows a state in which the structure 130 is formed by etching the third layer 13 as described above.

(3) Formation of conduction parts 160 to 163 (step S12 and FIG. 15D)
The conductive portions 160 to 163 are formed as follows a and b.
a. Formation of conical through-holes A predetermined portion of the structure 110 and the second layer 12 is wet-etched to form a weight-like through-hole that penetrates to the second layer 12. As the etchant, for example, 20% TMAH (tetramethylammonium hydroxide) can be used in the etching of the structure 110, and in the etching of the second layer 12, for example, buffered hydrofluoric acid (for example, HF = 5). 0.5 wt%, NH ₄ F = 20 wt% mixed aqueous solution).

b. Formation of Metal Layer For example, Al is deposited by vapor deposition or sputtering on the upper surface of the structure 110 and in the conical through holes to form the conductive portions 160 to 162. Unnecessary metal layers deposited on the upper surface of the structure 110 (metal layers outside the upper edges (not shown) of the conductive portions 160 to 162) are removed by etching.

(4) Bonding of base 140 (step S13 and FIG. 15E)
a. Production of Base 140 A substrate made of an insulating material (a glass substrate containing movable ions, such as Pyrex (registered trademark) glass) is provided with a driving electrode 144a, detection electrodes 144b to 144e, and wiring layers L2, L8 to L11. , For example, by a pattern made of Al containing Nd. In addition, by etching the base 140, 11 wide conical through holes 10 for forming the wiring terminals T1 to T11 are formed at predetermined positions.

  Prior to the formation of the drive electrode 144a and the like, a recess may be formed in the base 140 by etching or the like. In this case, the formation of the gap 10 in the structure 130 is not necessary. That is, the gap between the weight portion 132 and the base body 140 can be provided in either or both of the structure 130 and the base body 140.

b. Bonding of Semiconductor Substrate W (Structure 130) and Base 140 A getter material (trade name non-evaporable getter, manufactured by SAES Getters Japan) is put in the pocket 135, and the base 140 and the structure 130 are bonded by anodic bonding.
FIG. 15E shows a state in which the structure 130 and the base body 140 are joined.
At this time, the conductive portions 160 to 163 are formed before the anodic bonding with the base 140, and the continuity is taken up and down of the semiconductor substrate, so that the bonding is easier than in the case where the second layer 12 is not penetrated. can do.

(5) Formation of wiring terminals T1 to T11 (step S14 and FIG. 15F)
For example, a metal layer is formed in the order of a Cr layer and an Au layer on the upper surface of the base 140 and the conical through hole 10 by vapor deposition, sputtering, or the like. Unnecessary metal layers (metal layers outside the upper edge of the wiring terminal T) are removed by etching to form wiring terminals T1 to T11.

(6) Creation of structure 110 (etching of first layer 11, step S15, and FIG. 15G)
By etching the first layer 11, the opening 115 is formed and the structure 110 is formed. That is, an etching method that has erosion with respect to the first layer 11 and does not have erosion with respect to the second layer 12 is used to form predetermined regions (openings 115 a to 115 d) of the first layer 11. On the other hand, etching is performed in the thickness direction until the upper surface of the second layer 12 is exposed.

A resist layer having a pattern corresponding to the structure 110 is formed on the upper surface of the first layer 11, and an exposed portion not covered with the resist layer is eroded vertically downward. In this etching process, since the second layer 12 is not eroded, only predetermined regions (openings 115a to 115d) of the first layer 11 are removed.
FIG. 15G shows a state where the structure 110 is formed by etching the first layer 11 as described above.

(7) Creation of joint 120 (etching of second layer 12, step S16, and FIG. 15H)
Etching the second layer 12 forms the joint 120. That is, the second layer 12 is erodible with respect to the second layer 12, and the second layer 12 is etched with respect to the first layer 11 and the third layer 13 by an etching method without erosion. Etching is performed in the thickness direction and the layer direction from the exposed portion.

  In this etching process, it is not necessary to separately form a resist layer. That is, the structure 110 that is the remaining portion of the first layer 11 functions as a resist layer for the second layer 12. Etching is performed on the exposed portion of the second layer 12.

In the etching process for the second layer 12 (step S12), it is necessary to perform an etching method that satisfies the following two conditions. The first condition is to have a direction in the layer direction as well as the thickness direction, and the second condition is erosive to the silicon oxide layer but erodible to the silicon layer. Is not to.
The first condition is a condition necessary for preventing the silicon oxide layer from remaining in an unnecessary portion and preventing the degree of freedom of displacement of the weight portion 132. The second condition is a condition necessary for preventing the structure 110 made of silicon, which has already been processed into a predetermined shape, and the third layer 13 from eroding.

As an etching method that satisfies the first and second conditions, wet etching using buffered hydrofluoric acid (for example, a mixed aqueous solution of HF = 5.5 wt% and NH ₄ F = 20 wt%) can be given. Further, dry etching by the RIE method using a mixed gas of CF ₄ gas and O ₂ gas is also applicable.

In the above manufacturing process, it is necessary to perform the following etching method in the step of forming the structure 110 (step S15) and the step of forming the structure 130 (step S11).
The first condition is to have directionality in the thickness direction of each layer. The second condition is erosive to the silicon layer but not erodible to the silicon oxide layer. That is.

As an etching method that satisfies the first condition, an inductively coupled plasma etching method (ICP etching method) can be given. This etching method is effective when digging deep grooves in the vertical direction, and is a kind of etching method generally called DRIE (Deep Reactive Ion Etching).
In this method, an etching stage in which the material layer is dug while being eroded in the thickness direction and a deposition stage in which a polymer wall is formed on the side surface of the dug hole are alternately repeated. Since the side walls of the holes that have been dug are protected by the formation of polymer walls, it is possible to advance erosion almost only in the thickness direction.

On the other hand, in order to perform etching satisfying the second condition, an etching material having etching selectivity between silicon oxide and silicon may be used. For example, a mixed gas of SF ₆ gas and O ₂ gas may be used in the etching stage, and C ₄ F ₈ gas may be used in the deposition stage.

(8) Bonding of base 150 (step S17 and FIG. 15I)
1) Creation of Base 150 Etching a substrate made of an insulating material (a glass substrate containing movable ions, such as Pyrex (registered trademark) glass) to form a recess 153, and driving electrode 154a and detection electrodes 154b to 244e The wiring layers L1, L4 to L7 are formed at predetermined positions by a pattern made of Al containing Nd, for example.

2) Bonding of Semiconductor Substrate W (Structure 110) and Base 150 The structure 110 and the base 150 are bonded by anodic bonding. At this time, the structure 110 and the base 150 are placed in alignment with each other on a plate electrode (not shown) in the anodic bonding apparatus. A voltage is applied to the entire structure 110 through the wiring terminals T1 to T11, and the entire structure 110 and the base 150 can be bonded uniformly. That is, a voltage is applied to the block upper layer portion 114 and the fixing portion 111 via the wiring terminals T1 to T11, the block lower layer portion 134 (and the base 131), and the conduction portions 160 to 163, and the substrate 150 and the vacuum atmosphere Anodically bonded. As described above, the conduction portion 163 is used as a conduction portion for power supply for making the joint surface of the sensor structure at the time of anodic bonding have a substantially equipotential.
FIG. 15I shows a state in which the semiconductor substrate W and the base 150 are joined. The movable part of the sensor is vacuum sealed.

(9) Dicing of the semiconductor substrate W, the base 150, and the base 140 (step S18 and FIG. 15J)
For example, after the getter material in the pocket 135 is activated by heat treatment at 450 ° C., the semiconductor substrate W, the base body 150, and the base body 140 bonded to each other are cut with a dicing saw or the like, and the individual mechanical quantity sensors 100 are thus cut. To separate.

As described above, the present embodiment employs the following.
-About all the blocks aj, the conduction parts 160-163 are arrange | positioned and the conduction | electrical_connection between the structures 110 and 130 is ensured.
The base 140 is anodically bonded before the base 150. This order corresponds to whether or not the wiring terminals T1 to T11 are formed.

  At the time of anodic bonding of the base 150 and the structure 110, voltage can be applied to the block upper layer portions 114a to 114h via the wiring terminals T1 to T11, the block lower layer portions 134a to 134h, and the conduction portions 160 to 163. All of the block upper layer portions 114a to 114h are substantially equipotential. This results in the following advantages.

(1) The anodic bonding process is stabilized.
By adopting a structure having conductive portions in all the block upper layer portions 114a to 114h, it becomes possible to perform anodic bonding in a state where the bonding surfaces of the frame (fixed portion) and the block upper layer portion 114 are maintained at substantially the same potential. became. That is, substantially the same anodic bonding process is realized over the entire bonding surface. The joint is stabilized at the stepping part, and the electrical connection is stabilized.

(2) The generation of electrostatic attraction generated on the side of the substrate opposite to the bonding surface due to the floating potential is prevented.
“Sticking” means that the weight portion 132 adheres to the substrate during anodic bonding. The yield at the time of manufacturing the mechanical quantity sensor 100 is reduced. There is a possibility that the weight portion 132 is attracted to and adhered to either of the bases 140 and 150 (sticking) and does not function as a mechanical quantity sensor. As a result of all the block upper layer portions 114a to 114h being equipotential at the time of anodic bonding of the substrate 150, the weight portion 132 always generates an electrostatic attractive force on the substrate 150 side, and it is sufficient to take measures against sticking only on the substrate 150 side. As a countermeasure against sticking, a film for preventing sticking, for example, Cr may be formed on the bottom plate portion 152. By eliminating the floating potential, the failure mode due to sticking to the substrate side opposite to the bonding surface is eliminated.

  If some of the blocks a to j do not have the conducting portions 160 to 163, the potentials of the drive electrode 154a, the detection electrodes 154b to 154e, the drive electrode 144a, and the detection electrodes 144b to 144e cannot be determined (floating) ), And the weight portion 132 can be attracted to the base 150 (drive electrode 154a, detection electrodes 154b to 154e) side and the base 140 (drive electrode 144a, detection electrodes 144b to 144e) side by electrostatic attraction. There is a possibility that the weight part 132 may be attached (sticking).

  If the base body 150 on which the conductive portions 160 to 163 are not arranged is first anodic bonded, the potentials of the blocks a to j are not determined at the time of anodic bonding of the base body 140, the anodic bonding process is not stable, not only defective bonding but also sticking, etc. May be incurred. Since the pedestal 131 is located outside the mechanical quantity sensor 100, a voltage can be applied. However, since the blocks a to j are not connected to the pedestal 131, a potential floating occurs.

  Before the anodic bonding of the base body 150 and the structure 110, the base body 150 has conductivity at the temperature at the time of anodic bonding because it contains mobile ions. During this anodic bonding, the movable ions in the base 150 move, and the base 150 becomes a substantially insulator. Therefore, when the anodic bonding is performed in the order of the base 150 and the base 140, the base 150 becomes an insulator when the base 140 is anodic bonded, and even if a voltage is applied to the base 150, a voltage is applied to the blocks a to j. It does not contribute to the anodic bonding of the substrate 150.

(Other embodiments)
Embodiments of the present invention are not limited to the above-described embodiments, and can be expanded and modified. The expanded and modified embodiments are also included in the technical scope of the present invention.

In the above embodiment, the wiring terminals T <b> 1 to T <b> 11 are arranged on the base 140. In this relation, the creation procedure shown in FIG. 14 is used.
On the other hand, the wiring terminals T1 to T11 may be arranged on the base 150. In this case, for example, the creation procedure shown in FIG. 16 can be adopted. In this figure, step S11 and steps S15 and S16, and step S13 and step S17 in FIG. 14 are interchanged. Even in this case, the substrates are bonded in the order of the substrate (substrate 150) where the wiring terminals T1 to T11 are formed and the substrate (substrate 140) where the wiring terminals T1 to T11 are not formed. As a result, it is possible to apply a voltage to the blocks a to j via the wiring terminals T1 to T11 during the anodic bonding of the base 140 and the structure 130. That is, when anodic bonding the substrate on the side of vacuum sealing the movable portion of the sensor (bonded to the second sheet), the other substrate already bonded has a conductive portion (second conductive portion). In addition, a conducting part (first conducting part) that conducts vertically above and below the block part may be formed. Further, when manufactured in this order, the distance (gap interval) between the weight portion 132 and the connection portion 113 is different from that of the second substrate when the second substrate is bonded. Therefore, the electrostatic attractive force acting on the connecting portion 113 is smaller than that acting on the weight portion 132, and the effect of preventing the connecting portion 113 itself from being pulled to the base and breaking can be expected.

It is a disassembled perspective view showing the state which decomposed | disassembled the mechanical quantity sensor which concerns on one Embodiment of this invention. It is a disassembled perspective view showing the state which decomposed | disassembled the mechanical quantity sensor of FIG. 3 is a top view of a structure 110. FIG. It is a top view of a junction part. 3 is a top view of a structure 130. FIG. 3 is a bottom view of a base 150. FIG. 3 is a top view of a base body 140. FIG. 4 is a bottom view of a base body 140. FIG. It is sectional drawing showing the state cut | disconnected along BB of FIG. It is sectional drawing showing the state cut | disconnected along CC of FIG. It is the bottom view to which a part of FIG. 6 was expanded. FIG. 8 is an enlarged top view of a part of FIG. 7. It is sectional drawing which shows six sets of capacitive elements in the mechanical quantity sensor shown in FIG. It is a flowchart showing an example of the preparation procedure of the dynamic quantity sensor which concerns on the 1st Embodiment of this invention. It is sectional drawing showing the state of the mechanical quantity sensor in the preparation procedure of FIG. It is sectional drawing showing the state of the mechanical quantity sensor in the preparation procedure of FIG. It is sectional drawing showing the state of the mechanical quantity sensor in the preparation procedure of FIG. It is sectional drawing showing the state of the mechanical quantity sensor in the preparation procedure of FIG. It is sectional drawing showing the state of the mechanical quantity sensor in the preparation procedure of FIG. It is sectional drawing showing the state of the mechanical quantity sensor in the preparation procedure of FIG. It is sectional drawing showing the state of the mechanical quantity sensor in the preparation procedure of FIG. It is sectional drawing showing the state of the mechanical quantity sensor in the preparation procedure of FIG. It is sectional drawing showing the state of the mechanical quantity sensor in the preparation procedure of FIG. It is sectional drawing showing the state of the mechanical quantity sensor in the preparation procedure of FIG. It is a flowchart showing an example of the preparation procedure of the mechanical quantity sensor which concerns on the modification of this invention.

Explanation of symbols

100 Mechanical quantity sensor 110 Structure 111 Fixed part 111a Frame part 111b, 111c Protrusion part 112 (112a-112e) Displacement part 113 (113a-113d) Connection part 114 (114a-114j) Block upper layer part 115 (115a-115d) Opening 120, 121, 122, 123 Joint 130 Structure 131 Base 131a Frame 131b to 131d Projection 132 (132a-133e) Weight 133 Opening 134 (134a-134j) Block lower layer 135 Pocket 150 Base 151 Frame 152 Bottom plate Portion 153 Recess 154a Driving electrode 154b-154e Detection electrode 140 Base 144a Driving electrode 144b-144e Detection electrode 160-163 Conducting portion 10 Gap 11 Weight-shaped through holes L1, L2, L4-L11 Wiring layer T1-T11 Wiring Terminal E1 Driving electrode, detection electrode

Claims (2)

A first layer of a first semiconductor material, a second layer made of an insulating material, and a third semiconductor substrate layer are laminated in this order of a second semiconductor material having conductivity, said first Three layers, a pedestal having an opening, a weight part disposed in the opening, a plurality of first block members that are not connected to any of the pedestal and the weight part and are spaced apart from each other; Forming a first structure having:
Forming a plurality of first conductive portions penetrating the first structure and the second layer and electrically connecting each of the plurality of first block members and the first layer; ,
After formation of the plurality of first conductive portion is composed of an insulating material, have a through hole, film for sticking prevention in a region corresponding to the weight portion is disposed, said base a first substrate Joining to
Forming a plurality of second conducting portions electrically connected to the plurality of first block members on the first base after joining the base;
After formation of the plurality of second conducting portions, from the first layer, connecting a fixed portion joined to said base, and a displacement portion which is joined to the parts, and the displacement portion and the fixed portion Forming a second structure having a connecting portion to be connected, and a plurality of second block members joined to the plurality of first block members and spaced apart from each other;
After the formation of the second structure, the voltage is applied to all of the plurality of first and second block members through the second conductive portion, and is made of an insulating material and corresponds to the weight portion. An anti-sticking film is not disposed in a region to be bonded, and a second substrate is anodically bonded to the fixed portion;
A method of manufacturing a mechanical quantity sensor, comprising: A first layer of a first semiconductor material, a second layer made of an insulating material, and a third semiconductor substrate layer are laminated in this order of a second semiconductor material having conductivity, said first A fixed portion having an opening from one layer, a displacement portion disposed in the opening and displaced with respect to the fixed portion, a connection portion connecting the fixed portion and the displacement portion, and the fixed portion Forming a second structure having a plurality of second block members that are not connected to any of the displacement part and the connection part and are spaced apart from each other;
Forming a plurality of first conductive portions that penetrate the second structure and the second layer and electrically connect the plurality of second block members and the third layer;
Joining a second base made of an insulating material and having a through hole to the fixed portion after forming the plurality of first conductive portions ;
After joining of the fixed portion, and forming the first to second base, the second conductive portion of the plurality are electrically connected to the respective plurality of second block members,
After forming the plurality of second conductive portions, from the third layer, joined to the base joined to the fixed portion, the weight portion joined to the displacement portion, and joined to the plurality of first block members And forming a first structure having a plurality of first block members spaced apart from each other;
After the formation of the first structure, a voltage is applied to all of the plurality of first and second block members through the second conducting portion, so that the first structure is made of an insulating material and corresponds to the weight portion. An anodic bonding of the first substrate to the pedestal, wherein no sticking-preventing film is disposed in the area to be
A method of manufacturing a mechanical quantity sensor, comprising:

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