JP2010060337A - Mechanical quantity sensor and method for manufacturing laminated body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mechanical quantity sensor for reducing a residue of a resist when an electrode is formed, and a method for manufacturing a laminated body. <P>SOLUTION: The method for manufacturing the laminated body includes: a step for sequentially forming first, second and third conductor layers containing metal on a substrate; a step for patterning the third conductor layer; a step for patterning the second conductor layer by using the third patterned conductor layer as a mask; a step for patterning the first conductor layer by using the second patterned conductor layer as a mask; and a step for removing the third patterned conductor layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

A technique of a mechanical quantity sensor configured to detect a acceleration and an angular velocity by joining a transducer structure made of a semiconductor so as to be sandwiched between a pair of glass substrates is disclosed (for example, see Patent Document 1). The transducer structure has a weight, and the glass substrate has an electrode. The change in the posture of the weight is detected by the change in the capacitance between the weight and the electrode. As a result, a mechanical quantity (for example, acceleration) is detected. At this time, in order to facilitate the operation of the transducer structure, the transducer structure is sealed with a glass substrate and decompressed.
At this time, an electrode is formed by etching the metal material using the photoresist as a mask (see, for example, Patent Document 2). By patterning the photoresist, a mask is formed, and the photoresist is removed after etching the metal material.
JP 2007-192621 A Japanese Utility Model Publication No. 64-29836

  Incidentally, it may be difficult to remove the resist. For example, there is a case where the resist adheres firmly to the metal material and is difficult to remove by a remover (peeling solution) or plasma ashing. In this case, gas is generated from the resist residue, and the pressure around the sealed transducer structure may increase. This increase in pressure hinders the operation of the transducer structure and causes the performance of the mechanical quantity sensor to deteriorate. In particular, when detecting the angular velocity, since the transducer structure is vibrated, the vibration may be greatly attenuated.

  In view of the above, it is an object of the present invention to provide a mechanical quantity sensor and a method for manufacturing a laminate that can reduce resist residues during electrode formation.

  The method for manufacturing a laminate according to one aspect of the present invention includes a step of sequentially forming first, second, and third conductor layers each containing metal on a substrate, and patterning the third conductor layer. Patterning the second conductor layer using the patterned third conductor layer as a mask; and patterning the first conductor layer using the patterned second conductor layer as a mask. And removing the patterned third conductor layer.

  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. A fixed portion having an opening from the first layer of the semiconductor substrate in which three layers are sequentially stacked, a displacement portion disposed in the opening and displaced with respect to the fixed portion, and the fixed portion, Forming a first structure having a connecting portion for connecting to the displacement portion; and forming a first base body having a first electrode and made of a first insulating material. A step of bonding the first base to the fixed portion such that the first electrode faces the displacement portion, and a third layer is bonded to the displacement portion, and the bottom surface is Having a weight part, and surrounding the weight part, and on the fixed part Forming a second structure having a base to be joined, forming a joint for joining the first and second structures from the second layer, and a second electrode And a second base made of a second insulating material, and the second base is placed on the pedestal so that the second electrode faces the bottom surface of the weight portion. A first step of forming the first and second substrates, wherein at least one of the first and second insulating materials includes a metal on at least one of the first and second insulating materials, respectively. , Forming the second and third conductor layers in sequence, patterning the third conductor layer, and patterning the second conductor layer using the patterned third conductor layer as a mask And the putter And using the patterned second conductor layer as a mask, patterning the first conductor layer, and removing the patterned third conductor layer, At least one of the electrodes has the patterned first and second conductor layers.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the mechanical quantity sensor and laminated body which can reduce the residue of the resist at the time of formation of an electrode can be provided.

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 140, a top view of the base 150, and a bottom view of the base 150, 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 140, and the base 150 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. For the silicon constituting the structures 110 and 130, it is preferable to use a conductor material containing impurities such as boron as a whole. 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.

  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 114 (114a to 114j). Is done. 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 144a, which will be described later, installed on the lower 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 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 144b to 144e, which will be described later, installed on the lower surface of the base body 140 (the alphabets b to e of the displacement portion 112 and the detection electrodes). The alphabets b to e of the electrode 144 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 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 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 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 150 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 largely covered by the base 150, 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 154a, which will be described later, installed on the upper 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 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 154b to 154e, which will be described later, installed on the upper surface of the base 150 (the alphabets b to e of the weight part 132 are detected). The alphabets b to e of the electrode 154 correspond to each other in order). Details of this detection will be described later.

  The block lower layer portions 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 blocks obtained by joining the block upper layer portions 114a to 114h and the block lower layer portions 134a to 134h are hereinafter referred to as “blocks a to h”, respectively. The blocks a to h are used for wiring for supplying power to the driving electrodes 144b to 144e and 154b to 154e, respectively. Blocks obtained by joining the block upper layer portions 114i and 114j and the block lower layer portions 134i and 134j (hereinafter referred to as “block i and j”, respectively) are used for wiring applications for vibrating the displacement portion 112 in the Z-axis direction. It is done. Details of these will be described later.

The joint 120 connects the first and second 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 does not connect the first and second 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 162 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.
For example, the conductive portions 160 to 162 are formed by forming a metal layer such as Al on the edge, wall surface, and bottom of the through hole. Although the shape of the through hole is not particularly limited, it is preferable that the through holes of the conduction portions 160 to 162 have a wide cone shape because the metal layer can be effectively formed by sputtering such as Al.

  The base body 140 has, for example, an insulating material such as glass, a substantially rectangular parallelepiped shape, and has a frame portion 141 and a bottom plate portion 142. The frame portion 141 and the bottom plate portion 142 can be formed by forming a concave portion 143 having a substantially rectangular parallelepiped shape (for example, 2.5 mm in length and width and 5 μm in depth) so that the displacement portion can be displaced on the substrate.

The frame portion 141 is a frame-shaped substrate shape whose outer periphery and inner periphery are both substantially square. The outer periphery of the frame part 141 coincides with the outer periphery of the fixed part 111, and the inner periphery of the frame part 141 is smaller than the inner periphery of the fixed part 111.
The bottom plate portion 142 has a substantially square substrate shape whose outer periphery is substantially the same as the frame portion 141.
The reason why the concave portion 143 is formed in the base 140 is to secure a space for the displacement portion 112 to be displaced. The structure 110 other than the displacement part 112, that is, the fixed part 111 and the block upper layer parts 114a to 114j are joined to the base 140 by, for example, anodic bonding. A glass material containing movable ions such as Pyrex (registered trademark) glass is used as a material of the base 140 for anodic bonding.
Note that the base 140 can also be formed by bonding an insulating material by a method such as eutectic bonding.

  On the bottom plate part 142 (on the back surface of the base 140), first electrodes (driving electrodes 144a and detection electrodes 144b to 144e) are arranged so as to face the displacement part 112. Both the driving 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 near the center of the recess 143 so as to face the displacement portion 112a. 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 112e. The drive electrode 144a and the detection electrodes 144b to 144e are separated from each other.

  A wiring layer L1 that is electrically connected to the upper surface of the block upper layer portion 114i is connected to the driving electrode 144a. The detection electrode 144b has a wiring layer L4 electrically connected to the upper surface of the block upper layer portion 114b, and the detection electrode 144c 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 144d, and a wiring layer L7 electrically connected to the upper surface of the block upper layer portion 114a is connected to the electrode 144d for detection. Yes.

  For the drive electrode 144a, the detection electrodes 144b to 144e, and the wiring layers L1 and L4 to L7, for example, the first conductor layer containing the first conductor material is the upper layer (base 140 side), and the first conductor material A two-layer structure in which the second conductor layer containing the second conductor material having a higher melting point is the lower layer (the structure 110 side) can be used. Details of this will be described later.

The substrate 150 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 150 by anodic bonding. The weight portion 132 is not joined to the base 150 because the height is lower than the base 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 150 and the weight part 132 can be displaced.

  On the upper surface of the substrate 150, second electrodes (driving electrodes 154 a and detection electrodes 154 b to 154 e) are disposed so as to face the weight portion 132. The drive 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 upper surface of the base 150 so as to face the weight portion 132a. 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 132e. The drive electrode 154a and the detection electrodes 154b to 154e are separated from each other.

A wiring layer L2 electrically connected to the back surface of the block lower layer part 134j is connected to the driving electrode 154a.
The detection electrode 154b has a wiring layer L8 that is electrically connected to the back surface of the block lower layer portion 134c. The detection electrode 154c 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 154d, and a wiring layer L11 electrically connected to the back surface of the block lower layer part 134h is connected to the detection electrode 154e. Yes.

  For the drive electrode 154a, the detection electrodes 154b to 154e, and the wiring layers L2 and L8 to L11, for example, the first conductor layer containing the first conductor material is the lower layer (base 150 side), and the first conductor material A two-layer structure in which the second conductor layer containing the second conductor material having a higher melting point is the upper layer (the structure 130 side) can be used. Details of this will be described later.

  The base 150 is provided with wiring terminals T (T1 to T11) penetrating the base 150, and from the outside of the mechanical quantity sensor 100 to the drive electrodes 144a and 154a, the detection electrodes 144b to 144e, and 154b to 154e. 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 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. The wiring terminal T can be used as a connection terminal for connecting to an external circuit by, for example, wire bonding.
1 to 10, the base body 150 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 150 of the mechanical quantity sensor 100 can be arranged, for example, so as to be easily connected.

(Operation and wiring of mechanical quantity sensor 100)
The wiring and electrodes of the mechanical quantity sensor 100 will be described.
FIG. 11 is a cross-sectional view showing six sets of capacitive elements in the mechanical quantity sensor 100 shown in FIG. In FIG. 11, the part functioning as an electrode is shown by hatching. In FIG. 11, six sets of capacitive elements are illustrated, but as described above, the mechanical quantity sensor 100 includes 10 sets of capacitive elements.
One electrode of the 10 capacitive elements is a drive electrode 144a and detection electrodes 144b to 144e formed on the base 140, and a drive electrode 154a and detection electrodes 154b to 154e formed on the base 150.
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 structure 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 structure body 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 144a and the detection electrodes 144b to 144e formed on the base 140 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 are first members (stepping on) that are disposed between the block upper layer portion 114 and the base body 140 (regions in contact with the block upper layer portion 114). Part) and a second member for connecting the first member and the driving electrode 154a and the like. The first member is disposed in a region where the upper surface of the block upper layer portion 114 contacts the base body 140.

  The drive electrode 154a and the detection electrodes 154b to 154e formed on the base 150 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 are first members (stepping on) that are arranged between the block lower layer portion 134 and the base 150 (regions in contact with the block lower layer portion 134). Part) and a second member for connecting the first member and the driving electrode 154a and the like. The first member is disposed in a region where the lower surface of the block lower layer part 134 is in contact with the base 150.

  Wirings for these driving electrodes 144a and 154a and detection electrodes 144b to 144e and 154b to 154e 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 144e, 144b, 154b, 154c, 144c, 144d, 154d, 154e, and the driving electrodes 144a, 154a, 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 the conduction part 161, and both 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 the conductive material (silicon containing impurities), the block a in which the block upper layer portions 114a to 114j and the block lower layer portions 134a to 134j are joined. ˜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 144a and E1, the drive electrodes 144a and E1 are attracted to each other by 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 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 Z-axis negative direction. That is, by alternately applying a voltage between the drive electrodes 144a and E1 and between the drive electrodes 154a 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 144a and E1 (upper surface of the displacement portion 112a) and the drive electrodes 154a and E1 (lower surface of the weight portion 132a) serve as vibration applying portions, and the detection electrodes 144b to 144e, 154b to 154e, 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 drive electrodes 144a and E1 or between the drive electrodes 154a 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 144b to 144e and 154b to 154e.

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

  On the other hand, when the force F0y or the Coriolis force Fy in the positive Y direction is applied to the displacement portion 112, the drive electrode E1 (upper surface of the displacement portion 112c) and 144c, the detection electrode E1 (lower surface of the weight portion 132e), 154e The distance between the detection electrodes E1 (upper surface of the displacement portion 112e) and 144e, and the distance between the detection electrodes E1 (lower surface of the weight portion 132c) and 154c increase. As a result, the capacitance between the detection electrode E1 (upper surface of the displacement portion 112c) and 144c, between the detection electrode E1 (lower surface of the weight portion 132e) and 154e is increased, and the detection electrode E1 (upper surface of the displacement portion 112e), Between 144e, the capacitance between the detection electrode E1 (the lower surface of the weight portion 132c) and 154c decreases. That is, based on the difference in capacitance between the detection electrode E1 and the detection electrodes 144b to 144e and 154b to 154e, 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, 144b to 144e, 154b to 154e detect the inclination of the displacement portion 112 in the X and Y directions 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 144b to 144e, 154b to 154e, 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. 12 is a flowchart illustrating an example of a procedure for creating the mechanical quantity sensor 100. 13A to 13J are cross-sectional views showing the state of the mechanical quantity sensor 100 in the creation procedure of FIG. 12 (corresponding to a cross section obtained by cutting the mechanical quantity sensor 100 shown in FIG. 1 with CC). FIGS. 13A to 13J correspond to the mechanical quantity sensor 100 of FIG. 10 arranged upside down.

(1) Preparation of semiconductor substrate W (step S10 and FIG. 13A)
As shown in FIG. 13A, a semiconductor substrate W formed by stacking three layers of first, second, and third layers 11, 12, and 13 is prepared. The semiconductor substrate W has a diameter of about 150 to 200 mm, and a plurality of mechanical quantity sensors 100 are formed from one semiconductor substrate W.

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 110 (etching of first layer 11, step S11, and FIG. 13B)
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. 13B shows a state in which the structure 110 is formed by etching the first layer 11 as described above. At this time, the block upper layer portion 114 is defined.

(3) Creation of junction 120 (etching of second layer 12, step S12, and FIG. 13C)
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.

(4) Formation of conduction parts 160 to 162 (step S13 and FIG. 13D)
The conductive portions 160 to 162 are formed in the following manners 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). _.5wt%, it is possible to use a mixed aqueous solution) of NH 4 F = 20wt%.

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.

(5) Bonding of base 140 (step S14 and FIG. 13E)
1) Production of the base 140 A substrate made of an insulating material (a glass substrate containing movable ions such as Na ions, for example, Pyrex (registered trademark) glass) is etched to form a recess 143, and a drive electrode 144a is used for detection. The electrodes 144b to 144e and the wiring layers L1 and L4 to L7 are formed at predetermined positions. The reason why the glass contains mobile ions is because of later anodic bonding.

  As described above, the drive electrode 144a, the detection electrodes 144b to 144e, and the wiring layers L1 and L4 to L7 have a two-layer structure (the first conductor layer on the base 140 side and the second conductor on the structure 110 side). Layer). Details of this will be described later.

2) Bonding of the semiconductor substrate W and the base 140 The semiconductor substrate W and the base 140 are bonded by anodic bonding.
The base body 140 is anodically bonded before the structure 130 is formed. Since the base 140 is anodically bonded before forming the weight portion 132, the connecting portions 113a to 113d do not have a thin region and are not flexible. Even when an electrostatic attractive force is generated at the time of bonding, the displacement portion 112 is not attracted to the base 140. However, at the time of anodic bonding with the base 150, which will be described later, the displacement portion 112 is movably supported by the connection portion 113 and may be pulled toward the base 140 side.
FIG. 13E shows a state in which the semiconductor substrate W and the base 140 are joined.

(6) Creation of structure 130 (etching of third layer 13, step S15, and FIGS. 13F and 13G)
The structure 130 is formed in the following manners a and b.
a. Formation of gap 10 (FIG. 13F)
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. 13G)
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. 13G shows a state in which the structure 130 is formed by performing the above-described etching on the third layer 13. At this time, the block lower layer part 134 is defined and the blocks a to i are formed.

In the manufacturing process described above, it is necessary to perform the following etching method in the step of forming the structure 110 (step S11) and the step of forming the structure 130 (step S15).
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.

(7) Bonding of base 150 (step S16 and FIG. 13H)
a. Production of Base 150 A substrate made of an insulating material (a glass substrate containing movable ions such as Na ions, for example, Pyrex (registered trademark) glass), a driving electrode 154a, detection electrodes 154b to 154e, and a wiring layer L2, L8 to L11 are formed at predetermined positions. Further, by etching the base body 150, 11 wide conical through holes 11 for forming the wiring terminals T1 to T11 are formed at predetermined positions. The reason why the glass contains mobile ions is because of later anodic bonding.

  As described above, the drive electrode 154a, the detection electrodes 154b to 154e, and the wiring layers L2 and L8 to L11 have a two-layer structure (the first conductor layer on the base 150 side and the second conductor on the structure 130 side). Layer). Details of this will be described later.

  Here, as with the base 140, prior to the formation of the drive electrode 154a and the like, a recess may be formed in the base 150 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 150 can be provided in either or both of the structure 130 and the base 150.

b. Bonding of Semiconductor Substrate W and Substrate 150 A getter material (trade name non-evaporable getter manufactured by SAES Getters Japan Co., Ltd.) is put in the pocket 135, and the substrate 150 and the semiconductor substrate W are bonded by anodic bonding.
FIG. 13H shows a state in which the semiconductor substrate W and the base 150 are joined.

(8) Formation of wiring terminals T1 to T11 (step S17 and FIG. 13I)
For example, a Cr layer and an Au layer are formed in this order on the upper surface of the substrate 150 and the conical through-hole 11 by vapor deposition or sputtering. 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.

(9) Dicing of the semiconductor substrate W, the base 140, and the base 150 (step S18 and FIG. 13J)
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 140, and the base body 150 that are 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.

(Details of Formation of Driving Electrode 144a, Driving Electrode 154a, etc. on Bases 140, 150)
Hereinafter, driving electrodes 144a to the substrates 140 and 150 (driving electrodes 144a, detection electrodes 144b to 144e, and wiring layers L1, L4 to L7), driving electrodes 154a and the like (driving electrodes 154a, detection electrodes) 154b to 154e and wiring layer L2, L8 to L11) will be described in detail.

  FIG. 14 is a flowchart showing an example of a procedure for creating the driving electrode 144a and the like on the bases 140 and 150. 15A to 15D are cross-sectional views showing a part of the bases 140 and 150 in the creation procedure of FIG. Here, the bases 140 and 150 are represented as a substrate SUB. Further, it is assumed that the drive electrode 144a and the like, and the drive electrode 154a and the like are configured by the conductor layers C1 and C2 patterned.

(1) Formation of conductor layers C1 to C3 (step S20, FIG. 15A)
Conductive layers C1 to C3 are formed in order on the substrate SUB (bases 140 and 150). Vapor deposition, sputtering, ion plating, MO-CVD, or the like can be used to form the conductor layers C1 to C3. As will be described later, the conductor layers C1 to C3 are etched by etching materials M1 to M3, respectively.

Here, the etching rate of the conductor layer C3 by the etching material M3 is preferably three times or more the etching rate of the conductor layer C2. The etching rate of the conductor layer C2 by the etching material M2 is preferably at least three times the etching rate of the conductor layers C1 and C3. The etching rate of the conductor layer C1 by the etching material M1 is preferably three times or more the etching rate of the conductor layer C2.
A higher selection ratio (ratio of etching rates) is preferable. In order to obtain sufficient mask performance, it is required to be 3 times or more. If the selection ratio is less than three times, the thickness of the conductor layer C2 may decrease during etching of the conductor layer C1, and pinholes or the like may occur in the conductor layer C2.

  When materials having substantially high identity are used for the conductor layers C1 and C3, the etching materials M3 and M1 can be made substantially the same. At this time, patterning of the conductor layer C1, which will be described later, and removal of the conductor layer C3 are performed substantially simultaneously. Regardless of which etching material M1, M3 is used, if the etching rate of the conductor layers C1, C3 is within 10% of the etching rate of the conductor layer C1, the etching materials M1, C3 M3 can be considered to be nearly identical (having identity).

  As described above, the bases 140 and 150 are made of a glass material, but the process itself of FIG. 14 can use an insulating resin such as semiconductor, glass-epoxy, epoxy, or ceramic as the substrate SUB in general.

A material having metal can be used for the conductor layers C1 to C3.
For the conductor layers C1 and C3, a material having substantially high identity, for example, a conductor material mainly composed of the same material (at least one of Al, Cu, and Ag) can be used. Specifically, Al alloy such as pure Al, Al—Si, Al—Cu, Al—Nd, and Al—Si—Cu, Cu, and Ag can be used. For the conductor layers C1 and C3, additives themselves or materials having different amounts can be used. For example, a combination of pure Al and Al—Nd alloy, a combination of Al—Nd alloy and Al—Si, or a combination of Al—Nd alloy and Al—Cu alloy can be used for the conductor layers C1 and C3.

The thickness of each of the conductor layers C1 to C3 is preferably 50 nm or more. This is because if the film thickness is less than 50 nm, pinholes may be formed in the conductor layers C1 to C3.
By making the conductor layer C3 thinner than the conductor layer C1, it is possible to prevent the conductor layer C1 from being undercut when the conductor layer C3 is removed. Details of this will be described later.

  The conductor layer C2 can be made of a conductor material containing at least one of Cr, Ti, W, Ta, Mo, Ni, and Co, and nitrides and silicides thereof. By using these materials, sticking can be suppressed. “Sticking” means that the weight portion 132 adheres to the base 150 (or base 140) during anodic bonding. The yield at the time of manufacturing the mechanical quantity sensor 100 is reduced. Sticking is suppressed by using a material having a relatively high melting point for the conductor layer C2.

(2) Patterning of conductor layer C3 (step S21, FIG. 15B)
A mask (not shown) is formed on the third metal layer C3 with a resist or the like, and the conductor layer C3 is patterned with an etching material M3 using the mask as an etching mask. A mask such as a resist is removed by a remover (peeling solution), plasma ashing, or the like.
When the conductor layer C3 is made of an Al-based material (Al, Al alloy), etching is performed by wet etching or dry etching. In the case of dry etching, a halogen-based gas such as chlorine can be used as an etching gas. In the case of wet etching, a mixed solution of phosphoric acid, acetic acid and nitric acid can be used. As such a chemical solution, for example, a mixed acid aluminum solution manufactured by Wako Pure Chemical Industries, Ltd. can be used.

(3) Patterning of conductor layer C2 (step S22, FIG. 15C)
Using the patterned conductor layer C3 as an etching mask, the conductor layer C2 is patterned with an etching material M2. Since it is not necessary to form a resist on the conductor layer C2, residue of the resist on the conductor layer C2 is reduced.
When the conductor layer C2 is made of Cr, etching is performed by wet etching or dry etching. In the case of dry etching, a mixed gas of chlorine and oxygen can be used as the etching gas. In the case of wet etching, an etchant having a composition containing ceric ammonium nitrate or permanganate can be used. For example, MR-E2000 manufactured by The Inktec Co., Ltd. can be used as such a chemical solution.

(4) Patterning of conductor layer C1 (step S23)
Using the patterned conductor layer C2 as an etching mask, the conductor layer C1 is patterned with the etching material M1. Since there is no need to form a resist on the conductor layer C1, residue of the resist on the conductor layer C1 is reduced.
When the conductor layer C1 is made of an Al-based material, etching is performed by wet etching or dry etching. In the case of dry etching, a halogen-based gas such as chlorine can be used as an etching gas. In the case of wet etching, a mixed solution of phosphoric acid, acetic acid and nitric acid can be used. As such a chemical solution, for example, a mixed acid aluminum solution manufactured by Wako Pure Chemical Industries, Ltd. can be used.

(5) Removal of conductor layer C3 (step S24, FIG. 15D)
The conductor layer C3 is etched away with the etching material M3. As a result, patterned two-layered conductor layers C1 and C2 are formed.

  Here, the patterning of the conductor layer C1 (step S23) and the removal of the conductor layer C3 (step S24) may be performed in parallel. As described above, when materials having substantially high identity are used for the conductor layers C1 and C3, the etching materials M1 and M3 are substantially the same, and the patterning of the conductor layer C1 and the removal of the conductor layer C3 are performed almost simultaneously. The That is, when a material having substantially high identity is used for the conductor layers C1, C3, the patterning of the conductor layer C1 and the removal of the conductor layer C3 can be performed using the same etching means.

  As described above, if the conductor layer C3 is made thinner than the conductor layer C1, the amount of side etching due to the conductor layer C1 being exposed to the etchant until the conductor layer C3 is removed can be reduced. When side etching is performed, the strength of the driving electrode 144a and the like is reduced. In addition, it becomes difficult to maintain a desired dimension. However, side etching occurs in the case of isotropic etching. That is, in the case of isotropic etching, the significance of making the conductor layer C3 thinner than the conductor layer C1 is increased.

  As described above, it is possible to use the resist only when patterning the conductor layer C3 and not use the resist when patterning the conductor layers C1 and C2. That is, the resist is formed only on the conductor layer C3, and the conductor layer C3 is finally removed. For this reason, even if a resist residue remains on the conductor layer C3, it is removed together with the conductor layer C3.

  As a result, when the inside of the mechanical quantity sensor 100 is depressurized at the time of sealing, an increase in pressure due to the gas generated from the resist residue and, consequently, a decrease in performance of the mechanical quantity sensor 100 is prevented. An increase in the pressure in the mechanical quantity sensor 100 obstructs the operation of the weight part 132 and causes the performance of the mechanical quantity sensor 100 to deteriorate. In particular, when the angular velocity is detected, the weight part 132 is vibrated, so that the vibration may be greatly attenuated.

(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.

It is a disassembled perspective view showing the state which decomposed | disassembled the mechanical quantity sensor which concerns on the 1st Embodiment of this invention. It is a disassembled perspective view showing the state which decomposed | disassembled the mechanical quantity sensor of FIG. It is a top view of the 1st structure. It is a top view of a junction part. It is a top view of the 2nd structure. It is a bottom view of a base. It is a top view of the 2nd base. It is a bottom view of the 2nd base. 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 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 drive electrode 144a etc. to the base | substrate 140,150. FIG. 15 is a cross-sectional view illustrating a part of the bases 140 and 150 in the creation procedure of FIG. 14. FIG. 15 is a cross-sectional view illustrating a part of the bases 140 and 150 in the creation procedure of FIG. 14. FIG. 15 is a cross-sectional view illustrating a part of the bases 140 and 150 in the creation procedure of FIG. 14. FIG. 15 is a cross-sectional view illustrating a part of the bases 140 and 150 in the creation procedure of FIG. 14.

Explanation of symbols

100 Mechanical quantity sensor 110 1st structure 111 Fixing 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- 115 d) Opening 120, 121, 122, 123 Joint part 130 Second structure 131 Base 131 a Frame part 131 b to 131 d Protruding part 132 (132 a-133 e) Weight part 133 Opening 134 (134 a-134 j) Block lower layer part 135 Pocket 140 Base 141 Frame 142 Bottom plate 143 Recess 144a Driving electrode 144b-144e Detection electrode 150 Second base 154a Driving electrode 154b-154e Detection electrode 160-162 Conducting part 10 Gap 11 Weight-shaped through holes L1, L2, L4-L11 Wiring layer T1-T 1 wiring terminals E1 driving electrode, detection electrode

Claims (8)

Sequentially forming first, second, and third conductor layers each containing a metal on a substrate;
Patterning the third conductor layer;
Patterning the second conductor layer using the patterned third conductor layer as a mask;
Patterning the first conductor layer using the patterned second conductor layer as a mask;
Removing the patterned third conductor layer;
The manufacturing method of the laminated body which comprises this. The method for manufacturing a laminate according to claim 1, wherein at least a part of the step of patterning the first conductor layer and the step of removing the third conductor layer coexist. In the step of patterning the third conductor layer, the step of patterning the first conductor layer, and the step of removing the third conductor layer, the etching rates of the first and third conductor layers are different. An etching material that is within 10% of the etching rate of the first conductor layer is used.
The manufacturing method of the laminated body of Claim 1 or 2. The first to third etching rates of the first to third conductor layers made of the substantially same etching material are such that the first and third etching rates are three times or more of the second etching rate. Have,
The manufacturing method of the laminated body of any one of Claims 1 thru | or 3. The third conductor layer is thinner than the first conductor layer;
The manufacturing method of the laminated body of any one of Claims 1 thru | or 4. The melting point of the second conductor layer is higher than the melting point of the first conductor layer;
The manufacturing method of the laminated body of any one of Claims 1 thru | or 5. The first and third conductor layers include at least one of Al, Cu, and Ag;
The second conductor layer includes at least one of Cr, Ti, W, Ta, Mo, Ni, and Co, nitrides thereof, and silicides;
The manufacturing method of the laminated body of any one of Claims 1 thru | or 6. The first substrate of the semiconductor substrate in which a first layer made of a first semiconductor material, a second layer made of an insulating material, and a third layer made of a second semiconductor material having conductivity are laminated in order. A first portion having a fixed portion having an opening, a displacement portion disposed in the opening and displaced with respect to the fixed portion, and a connection portion connecting the fixed portion and the displacement portion. Forming a structure of
Forming a first substrate having a first electrode and made of a first insulating material;
Bonding the first base to the fixed portion such that the first electrode faces the displacement portion;
A second structure having a weight part joined from the third layer to the displacement part and having a bottom surface, and a pedestal arranged to surround the weight part and joined to the fixing part; Forming steps;
Forming a joint for joining the first and second structures from the second layer;
Forming a second substrate having a second electrode and made of a second insulating material;
Bonding the second base to the pedestal so that the second electrode faces the bottom surface of the weight part,
At least one of the steps of forming the first and second substrates is
Sequentially forming first, second, and third conductor layers each containing a metal on at least one of the first and second insulating materials;
Patterning the third conductor layer;
Patterning the second conductor layer using the patterned third conductor layer as a mask;
Patterning the first conductor layer using the patterned second conductor layer as a mask;
Removing the patterned third conductor layer;
At least one of the first and second electrodes has the patterned first and second conductor layers;
The manufacturing method of the mechanical quantity sensor characterized by the above-mentioned.

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