JP2019132737A - Manufacturing method for physical quantity sensor - Google Patents

Abstract

To provide a manufacturing method for a physical quantity sensor with which it is possible to form a sensor element with excellent processing accuracy while suppressing the increased complexity of a forming process.SOLUTION: The manufacturing method for a physical quantity sensor includes the steps: of joining a substrate to be processed to a substrate; and etching the substrate to be processed and forming a sensor element and a conductor part from the substrate to be processed. The sensor element comprises a movable structure displaceable relative to the substrate, and a first fixed structure separated from the movable structure. The conductor part includes a first conductor part electrically connected to the movable structure, and a second conductor part arranged by being spaced apart from the first conductor part and electrically connected to the first fixed structure. In the step for etching the substrate to be processed, a time of day at which etching of a region around the sensor element begins is later than a time of day at which etching of a region between the first and the second conductor parts begins.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a physical quantity sensor.

  For example, the acceleration sensor described in Patent Document 1 includes a substrate and a sensor element disposed on the substrate. In addition, the sensor element is a movable body including a fixed portion fixed to the substrate, a movable portion connected to the fixed portion via the spring portion, displaceable with respect to the substrate, and a movable electrode finger provided on the movable portion. And a fixed electrode finger fixed to the substrate and arranged to face the movable electrode finger. In such an acceleration sensor, when acceleration is applied and the movable portion is displaced with respect to the substrate, the gap between the movable electrode finger and the fixed electrode finger changes, and the gap between the movable electrode finger and the fixed electrode finger is changed according to the change. Therefore, the acceleration can be detected based on the change in the capacitance.

  In Patent Document 1, as a method for forming a sensor element, a conductive film is formed on a silicon substrate, and the sensor element is formed by dry etching the silicon substrate in this state. Finally, an unnecessary portion of the conductive film is formed. A method of removing is described. Thereby, each part of the silicon substrate can be electrically connected by the conductive film until the sensor element is formed. Therefore, unevenness of charge in the silicon substrate can be suppressed, and each part of the silicon substrate can be uniformly dry etched. Therefore, the sensor element can be formed with high processing accuracy.

JP 2013-140085 A

  However, in the method for forming a sensor element described in Patent Document 1, it is necessary to remove a part of the conductive film in order to separate the movable body and the fixed electrode finger after the dry etching is completed. For this reason, the number of steps for forming the sensor element increases, and the formation of the sensor element becomes complicated.

  The objective of this invention is providing the manufacturing method of the physical quantity sensor which can form a sensor element with the outstanding process precision, suppressing the complication of a formation process.

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

The method of manufacturing a physical quantity sensor of the present invention includes a step of bonding a substrate to be processed to a substrate,
Etching the substrate to be processed, and forming a sensor element and a conductor portion from the substrate to be processed.
The sensor element is
A movable structure displaceable with respect to the substrate;
A first fixed structure fixed to the substrate and separated from the movable structure,
The conductor portion is
A first conductor portion electrically connected to the movable structure;
A second conductor portion disposed apart from the first conductor portion and electrically connected to the first fixed structure,
In the step of etching the substrate to be processed, the time at which etching of the region between the first conductor portion and the second conductor portion is started is earlier than the time at which etching of the region around the sensor element is started. It is characterized by being slower.
Thereby, the potential and heat distribution in the substrate to be processed can be suppressed (preferably uniform), and the etching unevenness in the substrate to be processed can be reduced. Therefore, a sensor element can be formed with high processing accuracy, and a physical quantity sensor capable of detecting a physical quantity with higher accuracy can be obtained. Further, unlike the prior art described above, it is not necessary to perform another process such as removing the conductive film after forming the sensor element, so that the complexity of the process of forming the sensor element can be suppressed.

In the physical quantity sensor manufacturing method of the present invention, the step of etching the substrate to be processed includes:
Placing a mask on the substrate to be processed;
Etching the substrate to be processed through the mask, and
The mask is
A sensor element region overlapping with a region to be the sensor element of the substrate to be processed;
A first conductor portion region overlapping with a region to be the first conductor portion of the substrate to be processed;
A second conductor portion region that overlaps with the second conductor portion region of the substrate to be processed;
A gap region located between the first conductor portion region and the second conductor portion region,
It is preferable that the thickness of the gap region is smaller than the thicknesses of the sensor element region, the first conductor portion region, and the second conductor portion region.
Thereby, during etching, the gap region can be removed while leaving the sensor element region, the first conductor portion region, and the second conductor portion region, and from the time when etching of the region around the sensor element is started. In addition, the time at which etching of the region between the first conductor portion and the second conductor portion is started can be delayed. Therefore, the etching unevenness in the substrate to be processed can be reduced more reliably. Therefore, the sensor element can be formed more reliably with high processing accuracy.

In the physical quantity sensor manufacturing method of the present invention, the step of etching the substrate to be processed includes:
Placing a mask on the substrate to be processed;
Etching the substrate to be processed through the mask, and
The mask is
A sensor element region overlapping with a region to be the sensor element of the substrate to be processed;
A first conductor portion region overlapping with a region to be the first conductor portion of the substrate to be processed;
A second conductor portion region that overlaps with the second conductor portion region of the substrate to be processed;
A gap region located between the first conductor portion region and the second conductor portion region,
The etching rate of the gap region is preferably faster than the etching rates of the sensor element region, the first conductor portion region, and the second conductor portion region.
Thereby, during etching, the gap region can be removed while leaving the sensor element region, the first conductor portion region, and the second conductor portion region, and from the time when etching of the region around the sensor element is started. In addition, the time at which etching of the region between the first conductor portion and the second conductor portion is started can be delayed. Therefore, the etching unevenness in the substrate to be processed can be reduced more reliably. Therefore, the sensor element can be formed more reliably with high processing accuracy.

In the physical quantity sensor manufacturing method of the present invention, it is preferable that the gap region of the mask is removed during the step of etching the substrate to be processed through the mask.
Accordingly, the time at which etching of the region between the first conductor portion and the second conductor portion is started can be delayed more reliably than the time at which etching of the region around the sensor element is started. .

In the physical quantity sensor manufacturing method of the present invention, the sensor element region, the first conductor portion region, and the second conductor portion region of the mask are formed by the sensor element, the first conductor portion, and the second conductor portion. It is preferable that it remains until it is done.
Thereby, it is suppressed that a sensor element and a conductor part are etched unintentionally, and shape shift from the design of these each part can be controlled effectively.

In the physical quantity sensor manufacturing method of the present invention, the first wiring arranged on the substrate and electrically connecting the movable structure and the first conductor portion;
It is preferable to have a second wiring arranged on the substrate and electrically connecting the first fixed structure and the second conductor portion.
Accordingly, the movable structure and the first conductor portion can be electrically connected with a simple configuration, and the first fixed structure and the second conductor portion can be electrically connected with a simple configuration.

In the physical quantity sensor manufacturing method of the present invention, the sensor element has a second fixed structure that is fixed to the substrate and separated from the movable structure and the first fixed structure,
The conductor portion is disposed apart from the first conductor portion and the second conductor portion, and has a third conductor portion electrically connected to the second fixed structure,
The mask has a third conductor portion region that overlaps a region that becomes the third conductor portion of the substrate to be processed, and the gap region is also formed between the first conductor portion region and the third conductor portion region. It is preferable to have.
Thus, by arranging the first fixed structure and the second fixed structure with respect to the movable structure, it is possible to improve the physical quantity detection accuracy.

In the method of manufacturing a physical quantity sensor of the present invention, the movable structure is:
A movable part displaceable in a first direction with respect to the substrate;
A movable electrode finger provided in the movable part and having a longitudinal shape along a second direction intersecting the first direction;
The first fixed structure has a longitudinal shape along the second direction, is located on one side of the first direction with respect to the movable electrode finger, and faces the movable electrode finger through a gap. Having a first fixed electrode finger,
The second fixed structure has a longitudinal shape along the second direction, is located on the other side of the first direction with respect to the movable electrode finger, and faces the movable electrode finger via a gap. It is preferable to have a second fixed electrode finger.
As a result, the physical quantity sensor can detect the acceleration in the first direction. Therefore, the convenience of the physical quantity sensor is improved.

In the method of manufacturing a physical quantity sensor of the present invention, the method includes the step of bonding a lid to the substrate so as to cover the sensor element, which is performed after the sensor element and the conductor portion are formed.
It is preferable that the said conductor part is located in the outer side of the said cover body.
Thereby, a conductor part can be utilized as a terminal.

Preferably, the physical quantity sensor manufacturing method of the present invention includes a step of removing the conductor portion, which is performed after the sensor element and the conductor portion are formed.
Thereby, size reduction of a physical quantity sensor can be achieved.

It is a top view which shows the physical quantity sensor manufactured by the manufacturing method of the physical quantity sensor which concerns on 1st Embodiment of this invention. It is the sectional view on the AA line in FIG. It is the BB sectional view taken on the line in FIG. It is CC sectional view taken on the line in FIG. It is a figure which shows the voltage applied to the physical quantity sensor shown in FIG. It is a flowchart which shows the manufacturing process of the physical quantity sensor shown in FIG. It is a top view for demonstrating the manufacturing method of a physical quantity sensor. It is a top view for demonstrating the manufacturing method of a physical quantity sensor. It is a top view for demonstrating the manufacturing method of a physical quantity sensor. It is the DD sectional view taken on the line in FIG. It is a top view for demonstrating the manufacturing method of a physical quantity sensor. It is the EE sectional view taken on the line in FIG. 11 for demonstrating the manufacturing method of a physical quantity sensor. It is the EE sectional view taken on the line in FIG. 11 for demonstrating the manufacturing method of a physical quantity sensor. It is the EE sectional view taken on the line in FIG. 11 for demonstrating the manufacturing method of a physical quantity sensor. It is the EE sectional view taken on the line in FIG. 11 for demonstrating the manufacturing method of a physical quantity sensor. It is the EE sectional view taken on the line in FIG. 11 for demonstrating the manufacturing method of a physical quantity sensor. It is a top view for demonstrating the manufacturing method of a physical quantity sensor. It is the FF sectional view taken on the line in FIG. It is a top view for demonstrating the manufacturing method of a physical quantity sensor. It is a top view for demonstrating the manufacturing method of a physical quantity sensor. It is a top view which shows the physical quantity sensor manufactured by the manufacturing method of the physical quantity sensor which concerns on 2nd Embodiment of this invention. It is a top view for demonstrating the manufacturing method of the physical quantity sensor shown in FIG. It is a top view for demonstrating the manufacturing method of the physical quantity sensor shown in FIG. It is sectional drawing for demonstrating the manufacturing method of the physical quantity sensor which concerns on 3rd Embodiment of this invention. It is sectional drawing which shows the physical quantity sensor device carrying a physical quantity sensor. It is a perspective view which shows the personal computer carrying a physical quantity sensor. It is a perspective view which shows the mobile phone carrying a physical quantity sensor. It is a perspective view which shows the digital still camera carrying a physical quantity sensor. It is a perspective view which shows the motor vehicle carrying a physical quantity sensor.

  Hereinafter, the manufacturing method of the physical quantity sensor of this invention is demonstrated in detail based on embodiment shown to an accompanying drawing.

<First Embodiment>
First, the manufacturing method of the physical quantity sensor according to the first embodiment of the present invention will be described.

  FIG. 1 is a plan view showing a physical quantity sensor manufactured by the physical quantity sensor manufacturing method according to the first embodiment of the present invention. 2 is a cross-sectional view taken along line AA in FIG. 3 is a cross-sectional view taken along line BB in FIG. 4 is a cross-sectional view taken along the line CC in FIG. FIG. 5 is a diagram illustrating a voltage applied to the physical quantity sensor illustrated in FIG. 1. FIG. 6 is a flowchart showing manufacturing steps of the physical quantity sensor shown in FIG. 7 to 9 are plan views for explaining the method of manufacturing the physical quantity sensor. 10 is a cross-sectional view taken along the line DD in FIG. FIG. 11 is a plan view for explaining the method of manufacturing the physical quantity sensor. 12 to 16 are cross-sectional views taken along the line EE in FIG. 11 for explaining the method of manufacturing the physical quantity sensor. FIG. 17 is a plan view for explaining the method of manufacturing the physical quantity sensor. 18 is a cross-sectional view taken along line FF in FIG. 19 and 20 are each a plan view for explaining a method of manufacturing a physical quantity sensor.

  In the following, for convenience of explanation, the three axes orthogonal to each other are referred to as an X axis, a Y axis, and a Z axis, a direction parallel to the X axis is referred to as an “X axis direction”, and a direction parallel to the Y axis is referred to as a “Y axis direction. The direction parallel to the Z axis is also referred to as the “Z axis direction”. Further, the tip end side of each axis in the arrow direction is also referred to as “plus side”, and the opposite side is also referred to as “minus side”. Further, the Z axis direction plus side is also referred to as “upper”, and the Z axis direction minus side is also referred to as “lower”.

  A physical quantity sensor 1 shown in FIG. 1 is an acceleration sensor that can detect an acceleration Ax in the X-axis direction. Such a physical quantity sensor 1 is provided on the board 2, the sensor element 3 that detects the acceleration Ax (physical quantity) in the X-axis direction, and the lid that is joined to the board 2 so as to cover the sensor element 3. 10 and a conductor portion 5 provided on the substrate 2 and electrically connected to the sensor element 3.

  As shown in FIG. 1, the board | substrate 2 has the recessed part 21 open | released in the upper surface. The recess 21 is formed so as to overlap the sensor element 3 in a plan view from the Z-axis direction. The recess 21 functions as an escape portion for preventing contact between the sensor element 3 and the substrate 2. Further, the substrate 2 has groove portions 25, 26, 27 opened on the upper surface, and wirings 75, 76, 77 are arranged in the groove portions 25, 26, 27.

  The wirings 75, 76, and 77 are electrically connected to the sensor element 3, respectively. In addition, one end portions of the wirings 75, 76, and 77 are exposed to the outside of the lid body 10, and are electrically connected to the conductor portion 5 on the outside of the lid body 10. That is, the wirings 75, 76, and 77 function as wirings for electrically connecting the sensor element 3 and the conductor portion 5, respectively.

  As such a substrate 2, for example, a glass substrate made of a glass material containing alkali metal ions such as sodium ions (for example, borosilicate glass such as Pyrex glass or Tempax glass (both are registered trademarks)) is used. be able to. Thereby, as described later, the sensor element 3 and the substrate 2 can be bonded by anodic bonding, and these can be firmly bonded. However, the substrate 2 is not limited to a glass substrate, and for example, a silicon substrate or a ceramic substrate may be used. When a silicon substrate is used, it is preferable to use a high-resistance silicon substrate or a silicon substrate having a silicon oxide film (insulating oxide) formed on the surface by thermal oxidation or the like from the viewpoint of preventing a short circuit. .

  As shown in FIG. 2, the lid 10 has a recess 11 that opens to the lower surface side. The lid 10 is bonded to the upper surface of the substrate 2 so as to accommodate the sensor element 3 in the recess 11. A storage space S for storing the sensor element 3 is formed by the lid 10 and the substrate 2. The storage space S is preferably filled with an inert gas such as nitrogen, helium, and argon, and is about 1/10 to 1 atm at the operating temperature (about −40 ° C. to 120 ° C.). By setting the storage space S to about 1/10 to 1 atm, the viscous resistance is increased and the damping effect is exhibited, so that the vibration of the sensor element 3 can be quickly converged. Therefore, the detection accuracy of the acceleration Ax of the physical quantity sensor 1 is improved.

  Such a lid 10 is formed from a silicon substrate. However, the lid 10 is not limited to a silicon substrate, and may be formed of, for example, a glass substrate or a ceramic substrate. Moreover, it does not specifically limit as a joining method of the board | substrate 2 and the cover body 10, What is necessary is just to select suitably according to the material of the board | substrate 2 and the cover body 10, For example, the joining surface activated by anodic bonding and plasma irradiation Examples include activation bonding for bonding together, bonding using a bonding material such as glass frit, diffusion bonding for bonding metal films formed on the upper surface of the substrate 2 and the lower surface of the lid 10, and the like. In the present embodiment, as shown in FIG. 2, the substrate 2 and the lid body 10 are bonded via a glass frit 19 (low melting point glass).

  As shown in FIG. 1, the sensor element 3 is provided on the upper surface of the substrate 2. The sensor element 3 includes a movable structure 3 </ b> A that can be displaced with respect to the substrate 2, and a first fixed structure 3 </ b> B and a second fixed structure 3 </ b> C that are fixed to the upper surface of the substrate 2. The movable structure 3 </ b> A includes a pair of fixed portions 31 and 32 fixed to the upper surface of the substrate 2, a movable portion 33 disposed between the fixed portions 31 and 32, and located on the concave portion 21, and the movable portion 33. And a pair of spring portions 34 and 35 (beam portions) that connect the fixed portions 31 and 32, and a plurality of movable electrode fingers 36 that protrude from the movable portion 33 to both sides in the Y-axis direction. In such a movable structure 3A, when the acceleration Ax in the X-axis direction is applied, the movable portion 33 is displaced in the X-axis direction while elastically deforming the spring portions 34 and 35.

  On the other hand, the first fixed structure 3 </ b> B is fixed to the upper surface of the substrate 2 and has a plurality of first fixed electrode fingers 37 extending in the Y-axis direction. A plurality of second fixed electrode fingers 38 that are fixed and extend in the Y-axis direction. Each first fixed electrode finger 37 is positioned on the positive side in the X-axis direction and faces the corresponding movable electrode finger 36, and each second fixed electrode finger 38 is opposed to the corresponding movable electrode finger 36 in the X axis. It is located on the minus side of the direction. In other words, one movable electrode finger 36 is disposed between the pair of first and second fixed electrode fingers 37 and 38.

  The movable structure 3 </ b> A is electrically connected to the wiring 75 in the fixed portion 31, each first fixed electrode finger 37 is electrically connected to the wiring 76, and each second fixed electrode finger 38 is connected to the wiring 77. And are electrically connected.

  Such a sensor element 3 is formed, for example, by patterning a conductive silicon substrate doped with impurities such as phosphorus (P), boron (B), arsenic (As), etc. by etching (particularly dry etching). be able to. The sensor element 3 is bonded to the upper surface of the substrate 2 by anodic bonding. However, the material of the sensor element 3 and the bonding method between the sensor element 3 and the substrate 2 are not particularly limited.

  Further, as shown in FIG. 1, the conductor portion 5 is disposed (joined) on the upper surface of the substrate 2 outside the lid body 10. The conductor portion 5 includes a first conductor portion 55, a second conductor portion 56, and a third conductor portion 57. The first conductor portion 55, the second conductor portion 56, and the third conductor portion 57 are arranged apart from each other along the Y-axis direction. Specifically, the first conductor portion 55 is located at the center, the second conductor portion 56 is located on the Y axis direction plus side of the first conductor portion 55, and the first conductor portion 55 is located on the Y axis direction minus side of the first conductor portion 55. Three conductor portions 57 are located. Further, the first conductor portion 55, the second conductor portion 56, and the third conductor portion 57 each have a longitudinal shape (rectangular shape) along the Y-axis direction.

  However, the arrangement and shape of the first conductor portion 55, the second conductor portion 56, and the third conductor portion 57 are not particularly limited. For example, the 2nd conductor part 56 or the 3rd conductor part 57 may be located in a center part, and other two may be located in the both sides.

  As shown in FIG. 2, the first conductor portion 55 is disposed so as to overlap the groove portion 25 and is electrically connected to the wiring 75 disposed in the groove portion 25. Specifically, a convex portion 251 protruding from the bottom surface is provided at a portion overlapping the first conductor portion 55 of the groove portion 25, and a wiring 75 is formed so as to cover the convex portion 251. And the part located on the top face of the convex part 251 of the wiring 75 contacts the lower surface of the 1st conductor part 55, and the wiring 75 and the 1st conductor part 55 are electrically connected.

  As shown in FIG. 3, the second conductor portion 56 is disposed so as to overlap the groove portion 26 and is electrically connected to the wiring 76 disposed in the groove portion 26. Specifically, a convex portion 261 protruding from the bottom surface is provided at a portion overlapping the second conductor portion 56 of the groove portion 26, and a wiring 76 is formed so as to cover the convex portion 261. And the part located on the top face of the convex part 261 of the wiring 76 contacts the lower surface of the 2nd conductor part 56, and the wiring 76 and the 2nd conductor part 56 are electrically connected.

  As shown in FIG. 4, the third conductor portion 57 is disposed so as to overlap the groove portion 27 and is electrically connected to the wiring 77 disposed in the groove portion 27. Specifically, a convex portion 271 that protrudes from the bottom surface is provided in a portion that overlaps the third conductor portion 57 of the groove portion 27, and a wiring 77 is formed so as to cover the convex portion 271. And the part located on the top face of the convex part 271 of the wiring 77 contacts the lower surface of the 3rd conductor part 57, and the wiring 77 and the 3rd conductor part 57 are electrically connected.

  As described above, the wirings 75, 76, and 77 are brought into direct contact with the first, second, and third conductor portions 55, 56, and 57 without using other members, so that their electrical connection is good. It will be a thing. However, the electrical connection method between the wiring 75, 76, 77 and the first, second, and third conductor portions 55, 56, 57 is not particularly limited. For example, the wiring 75, 76, 77 and the first Conductive bumps are arranged between the second, third conductor portions 55, 56, 57, and the wirings 75, 76, 77 and the first, second, third conductor portions 55, 56 are interposed via the bumps. , 57 may be electrically connected.

  Such a conductor portion 5 is made of the same material as the sensor element 3. In the present embodiment, the conductor portion 5 is formed by, for example, patterning a conductive silicon substrate doped with impurities such as phosphorus (P), boron (B), and arsenic (As) by etching. The conductor portion 5 is bonded to the upper surface of the substrate 2 by anodic bonding. In particular, in this embodiment, the sensor element 3 and the conductor portion 5 are removed from the silicon substrate 30 by processing the silicon substrate 30 anodically bonded to the upper surface of the substrate 2 by dry etching, as will be described in the manufacturing method described later. It is formed in a lump. Thereby, the conductor part 5 can be formed on the board | substrate 2 without causing the increase in the manufacturing process of the physical quantity sensor 1. FIG.

  The thickness of the silicon substrate 30 is not particularly limited, but is preferably 10 μm or more and 400 μm or less, and more preferably 10 μm or more and 100 μm or less. As a result, the sensor element 3 and the conductor portion 5 can be reduced in size (reduced height) while ensuring sufficient strength. The silicon substrate 30 may be a thicker substrate so that it can be easily handled in the manufacturing process. For example, a substrate with a thickness of 100 μm to 600 μm can be used. In this case, it can be thinned to a thickness of 10 μm or more and 100 μm or less in the joining step described later.

  The first, second, and third conductor portions 55, 56, and 57 as described above function as terminals of the physical quantity sensor 1, and a bonding wire is connected to the upper surface thereof (see FIG. 25 described later). Thereby, the connection surface of the bonding wire becomes high, and when the bonding wire is connected to the first, second, and third conductor portions 55, 56, and 57 (when the capillary is pressed), the lid 10 is obstructed. It becomes difficult to become. Therefore, the bonding wire can be easily connected to the first, second, and third conductor portions 55, 56, and 57.

  In the present embodiment, since the first, second, and third conductor portions 55, 56, and 57 are made of silicon, the first, second, and third conductor portions 55, 56, and 57, bonding wires, There is a risk of lack of connection strength. Therefore, it is preferable to form a metal film (for example, a laminate of a Cr underlayer and an Au coating layer) on the upper surfaces (connection surfaces) of the first, second, and third conductor portions 55, 56, and 57. Thereby, the connection strength of the 1st, 2nd, 3rd conductor parts 55, 56, and 57 and a bonding wire can fully be raised.

  In the present embodiment, since the first, second, and third conductor portions 55, 56, and 57 and the sensor element 3 are formed from the silicon substrate 30, the first, second, and third conductor portions 55, 56, The upper surface of 57 and the upper surface of the sensor element 3 are located in the same plane. That is, the upper surfaces of the first, second, and third conductor portions 55, 56, and 57 and the upper surface of the sensor element 3 are flush with each other. Therefore, it is possible to know the height of the sensor element 3 that is covered with the lid 10 and cannot be seen from the height of the first, second, and third conductor portions 55, 56, and 57.

  The configuration of the physical quantity sensor 1 has been described above. When the physical quantity sensor 1 operates, for example, the voltage V1 in FIG. 5 is applied to the movable structure 3A via the wiring 75, and the first fixed electrode fingers 37 and the second fixed electrode fingers 38 are connected to the wirings 76 and 77, respectively. To the QV amplifier (charge voltage conversion circuit). A capacitance Ca is formed between each first fixed electrode finger 37 and each movable electrode finger 36, and a capacitance Cb is formed between each second fixed electrode finger 38 and each movable electrode finger 36. Is done.

  When acceleration Ax is applied to the physical quantity sensor 1, the movable portion 33 is displaced in the X-axis direction while elastically deforming the spring portions 34 and 35 based on the magnitude of the acceleration Ax. Along with this displacement, the gap between the first fixed electrode finger 37 and the movable electrode finger 36 and the gap between the second fixed electrode finger 38 and the movable electrode finger 36 change, and with this displacement, the capacitance Ca , Cb change. Therefore, the acceleration Ax can be detected based on the changes in the capacitances Ca and Cb.

  Note that the capacitance Cb decreases as the capacitance Ca increases, and conversely, the capacitance Cb increases as the capacitance Ca decreases. Therefore, a differential calculation (a signal corresponding to the magnitude of the electrostatic capacitance Ca) obtained from the wiring 76 and a detection signal (a signal corresponding to the magnitude of the electrostatic capacitance Cb) obtained from the wiring 77 are performed. By performing the subtraction process (Ca-Cb), the noise can be canceled and the acceleration Ax can be detected with higher accuracy.

  Next, a method for manufacturing the physical quantity sensor 1 will be described. As shown in FIG. 6, the manufacturing method of the physical quantity sensor 1 includes a preparation step S <b> 1 for preparing the substrate 2, and a joining step S <b> 2 for joining the sensor element 3 and the silicon substrate 30 that is a base material of the conductor portion 5 to the substrate 2 A dry etching step S3 for patterning the silicon substrate 30 by dry etching to form the sensor element 3 and the conductor portion 5, a lid joining step S4 for joining the lid 10 to the substrate 2, and a singulation step S5. have. Hereinafter, each process is demonstrated one by one.

[Preparation step S1]
First, as shown in FIG. 7, a glass substrate 20 as a base material of the substrate 2 is prepared. The glass substrate 20 includes a plurality of individualized regions K arranged in a matrix, and each individualized region K is formed with a recess 21 and groove portions 25, 26, and 27. Next, in each singulated region K, wirings 75, 76, 77 are arranged in the groove portions 25, 26, 27.

[Jointing step S2]
Next, as shown in FIG. 8, a silicon substrate 30 (substrate to be processed) serving as a base material for the sensor element 3 and the conductor portion 5 is prepared, and the silicon substrate 30 is bonded to the upper surface of the glass substrate 20. The bonding method between the silicon substrate 30 and the glass substrate 20 is not particularly limited, but in the present embodiment, bonding is performed by an anodic bonding method. Next, if necessary, the silicon substrate 30 is thinned by CMP (chemical mechanical polishing) or the like, and then doped (diffusion) with impurities such as phosphorus (P), boron (B), and arsenic (As). Thus, conductivity is imparted. The order in which the impurities are doped is not particularly limited, and may be before the silicon substrate 30 is thinned or before the silicon substrate 30 is bonded to the glass substrate 20.

[Dry etching step S3]
Next, as shown in FIG. 9, a hard mask HM (mask) having etching resistance is formed on the upper surface of the silicon substrate 30. Note that having etching resistance means that the etching rate of the hard mask HM is sufficiently low with respect to the silicon substrate 30 (for example, 1/10 or less).

  The hard mask HM is formed corresponding to the shape of the sensor element 3 and the conductor portion 5 for each individual segment K. Specifically, the hard mask HM formed in each singulated region K includes a sensor element region HM1 that overlaps a region 300 that later becomes the sensor element 3 and a region 550 that later becomes the first conductor portion 55 of the silicon substrate 30. A first conductor portion region HM5 that overlaps with the second conductor portion region HM6 that overlaps with a region 560 that later becomes the second conductor portion 56, a third conductor portion region HM7 that overlaps with a region 570 that later becomes the third conductor portion 57, A gap region HM8 located between the first conductor portion region HM5 and the second conductor portion region HM6, and a gap region HM9 located between the first conductor portion region HM5 and the third conductor portion region HM7. doing.

  Further, as shown in FIG. 10, the thickness D1 of the gap region HM8 and the gap region HM9 is the thickness of the sensor element region HM1, the first conductor portion region HM5, the second conductor portion region HM6, and the third conductor portion region HM7. It is smaller than D2. The sensor element region HM1, the first conductor portion region HM5, the second conductor portion region HM6, and the third conductor portion region HM7 are formed to be sufficiently thick so as not to disappear during the subsequent dry etching (so as not to be removed by etching). On the other hand, the gap region HM8 and the gap region HM9 are formed to be sufficiently thin so as to disappear during the subsequent dry etching (so as to be removed by etching). The relationship between the thicknesses D1 and D2 is not particularly limited, but can be, for example, about 0.01D2 ≦ D1 ≦ 0.2D2.

  Such a hard mask HM can be formed as follows, for example. First, the surface (upper surface) of the silicon substrate 30 is thermally oxidized to form a silicon oxide film. Next, a mask is formed on the sensor element region HM1, the first conductor portion region HM5, the second conductor portion region HM6, and the third conductor portion region HM7, and the silicon oxide film is halfway in the thickness direction through the mask. Etch. Next, after removing the mask, a new mask is formed on the sensor element region HM1, the first conductor portion region HM5, the second conductor portion region HM6, the third conductor portion region HM7, the gap region HM8, and the gap region HM9. The hard mask HM is formed by etching the silicon oxide film through the mask.

  Next, the silicon substrate 30 is dry-etched through the hard mask HM. As a result, as shown in FIG. 11, the sensor element 3 and the conductor portion 5 are collectively formed from the silicon substrate 30 for each singulated region K. The dry etching method is not particularly limited. For example, a dry Bosch method combining an etching process using a reactive plasma gas and a deposition process can be used.

  The dry etching process will be described in detail. First, as shown in FIG. 12, dry etching of a portion R1 that does not overlap with the hard mask HM of the silicon substrate 30 is started. During this dry etching, the hard mask HM is gradually dry-etched together with the silicon substrate 30, and at some point, as shown in FIG. 13, the gap region HM8 and the gap region HM9 (not shown in FIG. 13; not shown in FIG. 13). The same applies to FIG. 16, and thereafter, dry etching is also started for the portion R2 that overlaps the gap region HM8 and the gap region HM9 of the silicon substrate 30, as shown in FIG. That is, dry etching of the portion R2 that overlaps the gap region HM8 and the gap region HM9 of the silicon substrate 30 is started later than the portion R1 (region around the sensor element region HM1) that originally did not overlap the hard mask HM. . In other words, the region (the first conductor portion 55 and the second conductor) that overlaps the gap region HM8 and the gap region HM9 from time T1 when the dry etching of the region (part R1) around the sensor element region HM1 of the silicon substrate 30 is started. The region between the portion 56 and the region between the first conductor portion 55 and the third conductor portion 57. The time T2 when the dry etching of the portion R2) is started is later.

  Therefore, as shown in FIG. 15, when the dry etching of the portion R1 (region around the sensor element region HM1) that originally did not overlap with the hard mask HM is completed and the sensor element 3 is formed, the gap region HM8 is formed. The dry etching of the portion R2 that overlaps the gap region HM9 is not completed, and the silicon substrate 30 remains in the portion R2. When the dry etching is further continued, as shown in FIG. 16, the portion R2 that overlaps the gap region HM8 and the gap region HM9 of the silicon substrate 30 is also removed, and the conductor portion 5 (the first conductor portion 55, the first conductor portion 55) is removed. Two conductor portions 56 and a third conductor portion 57) are formed. That is, the time T3 (the time at which the first, second, and third conductor portions 55, 56, and 57 are separated) from which the first, second, and third conductor portions 55, 56, and 57 are formed from the silicon substrate 30 is It is later than the time T4 when the sensor element 3 is formed from the silicon substrate 30.

  Thus, since the time T3 is later than the time T4, as shown in FIGS. 17 and 18, until the sensor element 3 is formed for each singulated region K, the first, second, and second The three conductor portions 55, 56, 57 are connected without being separated, and each portion of the silicon substrate 30 (particularly, the portion that becomes the sensor element 3) is electrically connected via the wirings 75, 76, 77. Can be maintained. Thereby, the electric charge stored in the silicon substrate 30 by the electric field applied during dry etching can be made uniform for each singulated region K. Furthermore, heat is transferred through the wirings 75, 76, and 77, and the temperature unevenness in the silicon substrate 30 can be reduced for each singulated region K.

  The sensor element region HM1, the first conductor portion region HM5, the second conductor portion region HM6, and the third conductor portion region HM7 remain until the sensor element 3 and the conductor portion 5 are formed from the silicon substrate 30. . Thereby, it is suppressed that the sensor element 3 and the conductor part 5 are etched unintentionally, and the shape shift from the design of these each part can be suppressed effectively.

  In dry etching, the etching rate (processing speed) varies depending on the amount of charge in the silicon substrate 30 and the temperature of the silicon substrate 30. Therefore, as described above, by making the charges in the silicon substrate 30 uniform for each individualized region K and reducing temperature unevenness, each part of the silicon substrate 30 can be processed more uniformly. As described above, in this embodiment, until the sensor element 3 is formed for each singulated region K, the charge in the silicon substrate 30 can be made uniform and the temperature unevenness can be reduced. The sensor element 3 can be formed with high accuracy. Therefore, the physical quantity sensor 1 that can effectively suppress the shape deviation from the design of the sensor element 3 and can accurately detect the acceleration Ax.

  In particular, in the present embodiment, as shown in FIGS. 9 and 10, in the separated region K adjacent to each other, the hard mask HM includes the second conductor portion region HM6 located in one separated region K, and the other A gap region HM10 having a thickness D1 is also provided between the third conductor portion region HM7 and the third conductor portion region HM7. Therefore, in the present embodiment, until the sensor element 3 is formed for each singulated region K, the entire silicon substrate 30 is electrically and thermally connected via the wirings 75, 76, and 77. Become. Therefore, the charge can be made uniform and temperature unevenness can be reduced over the entire silicon substrate 30. As a result, the plurality of sensor elements 3 formed for each individualized region K are homogeneous to each other, and a plurality of physical quantity sensors 1 having a small difference in characteristics can be obtained. Therefore, the yield of the physical quantity sensor 1 is improved, and the manufacturing cost can be reduced.

[Cover body joining step S4]
Next, as shown in FIG. 19, a silicon substrate 100 as a base material of the lid 10 is prepared, and the silicon substrate 100 is bonded to the upper surface of the glass substrate 20 through the glass frit 19. Thereby, the some physical quantity sensor 1 formed integrally is obtained.

[Individualization step S5]
Next, the glass substrate 20 is cut along the scribe line L shown in FIG. As a result, as shown in FIG. 20, a plurality of separated physical quantity sensors 1 are obtained.

  The method for manufacturing the physical quantity sensor 1 has been described above. As described above, the method of manufacturing the physical quantity sensor 1 includes the bonding step S2 for bonding the silicon substrate 30 (substrate to be processed) to the substrate 2, the silicon substrate 30 is etched, the sensor element 3 and the conductor from the silicon substrate. And a dry etching step S3 for forming the portion 5. The sensor element includes a movable structure 3A that is displaceable with respect to the substrate 2 and a first fixed structure 3B that is fixed to the substrate 2 and separated from the movable structure 3A. The conductor portion 5 is arranged to be separated from the first conductor portion 55 and the first conductor portion 55 electrically connected to the movable structure 3A, and is electrically connected to the first fixed structure 3B. A second conductor portion 56. Then, in the step of etching the silicon substrate 30 (dry etching step S3), the first conductor portion 55 and the second conductor portion are started from time T1 (at the start of etching) at which etching of the area around the sensor element 3 is started. The time T2 (at the start of etching) at which the etching of the region between 56 and 56 is started is later. Thereby, in particular, when the sensor element 3 is formed by dry etching the silicon substrate 30, the potential and heat distribution in the silicon substrate 30 can be suppressed (preferably uniform). Etching unevenness in the silicon substrate 30 can be reduced. Therefore, the sensor element 3 can be formed with high processing accuracy, and the physical quantity sensor 1 can detect the acceleration Ax with higher accuracy. Furthermore, unlike the prior art described above, it is not necessary to perform another process such as removing the conductive film after the sensor element 3 is formed, so that the process of forming the sensor element 3 can be prevented from becoming complicated. .

  Further, as described above, in the step of etching the silicon substrate 30 (dry etching step S3), the step of disposing the hard mask HM (mask) on the silicon substrate 30 and the etching of the silicon substrate 30 through the hard mask HM are performed. And a process. In addition, the hard mask HM includes a sensor element region HM1 that overlaps a region that becomes the sensor element 3 of the silicon substrate 30, a first conductor portion region HM5 that overlaps a region that becomes the first conductor portion 55 of the silicon substrate 30, and the silicon substrate 30. The second conductor portion region HM6 that overlaps the region that becomes the second conductor portion 56, and the gap region HM8 that is located between the first conductor portion region HM5 and the second conductor portion region HM6. The thickness D1 of the gap region HM8 is smaller than the thickness D2 of the sensor element region HM1, the first conductor portion region HM5, and the second conductor portion region HM6. Thus, during the dry etching, the gap region HM8 can be removed while leaving the sensor element region HM1, the first conductor portion region HM5, and the second conductor portion region HM6. The time T2 at which the etching of the region between the first conductor portion 55 and the second conductor portion 56 is started can be delayed from the time T1 at which the etching of the region around the sensor element 3 is started.

  Further, as described above, the gap region HM8 of the hard mask HM is removed during the process of etching the silicon substrate 30 through the hard mask HM. Thereby, the time T2 at which the etching of the region between the first conductor portion 55 and the second conductor portion 56 is started more reliably than the time T1 at which the etching of the region around the sensor element 3 is started. Can be late.

  In addition, as described above, the sensor element 3, the first conductor portion 55, and the second conductor portion 56 are formed in the sensor element region HM1, the first conductor portion region HM5, and the second conductor portion region HM6 of the hard mask HM. Remains. Thereby, it is suppressed that the sensor element 3 and the conductor part 5 are etched unintentionally, and the shape shift from the design of these each part can be suppressed effectively.

  Further, as described above, the sensor element 3 has the second fixed structure 3C that is fixed to the substrate 2 and separated from the movable structure 3A and the first fixed structure 3B. In addition, the conductor portion 5 includes a third conductor portion 57 that is disposed apart from the first conductor portion 55 and the second conductor portion 56 and is electrically connected to the second fixed structure 3C. Further, the hard mask HM has a third conductor portion region HM7 that overlaps with a region that becomes the third conductor portion 57 of the silicon substrate 30, and a gap region between the first conductor portion region HM5 and the third conductor portion region HM7. It has a gap region HM9 similar to HM8. Thus, the detection accuracy of the acceleration Ax can be improved by disposing the first fixed structure 3B and the second fixed structure 3C with respect to the movable structure 3A.

  In addition, as described above, the physical quantity sensor 1 is disposed on the substrate 2, and the wiring 75 (first wiring) that electrically connects the movable structure 3 </ b> A and the first conductor 55 is disposed on the substrate 2. The wiring 76 (second wiring) that electrically connects the first fixed structure 3B and the second conductor portion 56 and the second fixed structure 3C and the third conductor portion 57 are electrically connected. Wiring 77 (third wiring). Accordingly, the movable structure 3A and the first conductor portion 55 can be electrically connected with a simple configuration, and the first fixed structure 3B and the second conductor portion 56 can be electrically connected with a simple configuration. The second fixed structure 3C and the third conductor portion 57 can be electrically connected with a simple configuration.

  As described above, the movable structure 3A includes the movable portion 33 that can be displaced in the X-axis direction (first direction) with respect to the substrate 2, and the Y-axis that is provided in the movable portion 33 and intersects the X-axis direction. And a movable electrode finger 36 having a longitudinal shape along the direction (second direction). The first fixed structure 3B has a longitudinal shape along the Y-axis direction, is located on the plus side (one side) in the X-axis direction with respect to the movable electrode finger 36, and is interposed between the movable electrode finger 36 and a gap. The first fixed electrode fingers 37 are opposed to each other. Further, the second fixed structure 3C has a longitudinal shape along the Y-axis direction, is located on the negative side (the other side) in the X-axis direction with respect to the movable electrode finger 36, and has a gap with the movable electrode finger 36. The second fixed electrode fingers 38 are opposed to each other. Thus, the physical quantity sensor 1 can be used as an acceleration sensor that can detect the acceleration Ax in the X-axis direction. Therefore, the physical quantity sensor 1 is highly convenient.

  Further, as described above, the method of manufacturing the physical quantity sensor 1 is performed after the sensor element 3 and the conductor portion 5 are formed, and the step of bonding the lid body 10 to the substrate 2 so as to cover the sensor element 3 (lid body bonding) Step S4). The conductor portion 5 is located outside the lid body 10. Thereby, the conductor part 5 can be used as a terminal for connecting the external device and the sensor element 3. Therefore, electrical connection between the external device and the sensor element 3 is facilitated.

<Second Embodiment>
Next, a method for manufacturing a physical quantity sensor according to the second embodiment of the invention will be described.

  FIG. 21 is a plan view showing a physical quantity sensor manufactured by the physical quantity sensor manufacturing method according to the second embodiment of the present invention. 22 and 23 are plan views for explaining a method of manufacturing the physical quantity sensor shown in FIG.

  The manufacturing method of the physical quantity sensor 1 according to the present embodiment is the same as the manufacturing method of the physical quantity sensor 1 of the first embodiment described above except that it mainly includes a step of removing the conductor portion 5. In the following description, the manufacturing method of the physical quantity sensor 1 of the second embodiment will be described focusing on the differences from the first embodiment described above, and description of similar matters will be omitted. 21 to 23, the same reference numerals are given to the same configurations as those of the first embodiment described above.

  As shown in FIG. 21, in the physical quantity sensor 1 of the present embodiment, the conductor portion 5 (first, second, and third conductor portions 55, 56, and 57) is omitted from the first embodiment described above. Instead, some of the portions of the wirings 75, 76, 77 exposed from the lid body 10 function as connection pads P. Thus, the physical quantity sensor 1 can be reduced in size by omitting the conductor portion 5.

  Next, a method for manufacturing such a physical quantity sensor 1 will be described. The manufacturing method of the physical quantity sensor 1 is the same as that of the first embodiment described above, and includes the preparation step S1, the joining step S2, the dry etching step S3, the lid joining step S4, and the singulation step S5. Have. In addition, since the manufacturing method of this embodiment is mainly different from the above-described first embodiment in the individualization step S5, the following description will be given in the individualization step S5. Description is omitted.

[Individualization step S5]
FIG. 22 shows a state after the lid joining step S4. In this state, the conductor portion 5 is disposed so as not to overlap with the connection pad P in each singulated region K. And in this process, the board | substrate 2 is cut | disconnected along the scribe line L as shown in the figure, and is separated into pieces for every separated area K. Thereby, the physical quantity sensor 1 is cut between the conductor part 5 and the connection pad P, and the conductor part 5 is detached from the physical quantity sensor 1. Therefore, as shown in FIG. 23, the physical quantity sensor 1 with the conductor portion 5 removed is obtained.

  Thus, the manufacturing method of the physical quantity sensor 1 of the present embodiment is performed after the sensor element 3 and the conductor portion 5 are formed, and includes a step of removing the conductor portion 5. Thereby, for example, compared with 1st Embodiment mentioned above, size reduction of the physical quantity sensor 1 can be achieved.

  Also according to the second embodiment, the same effects as those of the first embodiment described above can be exhibited.

<Third Embodiment>
Next, a method for manufacturing a physical quantity sensor according to the third embodiment of the invention will be described.

  FIG. 24 is a cross-sectional view for explaining the method of manufacturing a physical quantity sensor according to the third embodiment of the invention.

  The manufacturing method of the physical quantity sensor 1 according to the present embodiment is the same as the manufacturing method of the physical quantity sensor 1 of the first embodiment described above, except that the configuration of the hard mask HM is different. In the following description, the manufacturing method of the physical quantity sensor 1 of the third embodiment will be described with a focus on the differences from the first embodiment described above, and description of similar matters will be omitted. In FIG. 24, the same reference numerals are assigned to the same configurations as those of the first embodiment described above.

  As shown in FIG. 24, in the hard mask HM of the present embodiment, the sensor element region HM1, the first conductor portion region HM5, the second conductor portion region HM6, the third conductor portion region HM7, the gap regions HM8, HM9, Is formed as a separate body. Further, the constituent materials of the sensor element region HM1, the first conductor portion region HM5, the second conductor portion region HM6, and the third conductor portion region HM7 are different from the constituent materials of the gap regions HM8 and HM9. The etching resistance when dry etching the silicon substrate 30 through the hard mask HM is such that the constituent materials of the gap regions HM8 and HM9 are the sensor element region HM1, the first conductor portion region HM5, and the second conductor portion region. It is lower than HM6 and the third conductor portion region HM7. In other words, the etching rate when the silicon substrate 30 is dry-etched through the hard mask HM is such that the constituent materials of the gap regions HM8 and HM9 are the sensor element region HM1, the first conductor portion region HM5, and the second conductor portion. It is faster than the region HM6 and the third conductor portion region HM7.

  In this way, by setting the etching rates of the gap regions HM8 and HM9 faster than the etching rates of the sensor element region HM1, the first conductor portion region HM5, the second conductor portion region HM6, and the third conductor portion region HM7, When the time difference between T1 and time T2 is the same, for example, the thickness D1 of the gap regions HM8 and HM9 can be increased as compared to the first embodiment described above (when the etching rates of the respective parts are the same). Therefore, excessive thinning of the gap regions HM8 and HM9 is suppressed, and the formation of the gap regions HM8 and HM9 is facilitated. In addition, the gap regions HM8 and HM9 can be more reliably removed during dry etching.

  The etching rates of the gap regions HM8 and HM9 are not particularly limited. For example, the etching rates of the sensor element region HM1, the first conductor portion region HM5, the second conductor portion region HM6, and the third conductor portion region HM7 are 5%. It is preferably at least twice, and more preferably at least 10 times. As a result, the etching rates of the gap regions HM8 and HM9 can be sufficiently increased, and the gap regions HM8 and HM9 can be more reliably removed during dry etching. The constituent materials of the gap regions HM8 and HM9 are not particularly limited, but the sensor element region HM1, the first conductor portion region HM5, the second conductor portion region HM6, and the third conductor portion region HM7 are made of silicon oxide. In this case, for example, a metal material such as chromium, aluminum, nickel, palladium, titanium, platinum, gold, copper, or an alloy containing these metal materials can be used.

  If the silicon substrate 30 is dry-etched through such a hard mask HM, the gap regions HM8 and HM9 are removed during the dry etching, and the portions that overlap the gap regions HM8 and HM9 of the silicon substrate 30 are also dry-etched. Therefore, the same effects as those of the first embodiment described above can be exhibited. In the present embodiment, the thickness D1 of the gap regions HM8 and HM9 is smaller than the thickness D2 of the sensor element region HM1, the first conductor portion region HM5, the second conductor portion region HM6, and the third conductor portion region HM7. However, it is not limited to this, D1 = D2 may be sufficient and D1> D2 may be sufficient.

  As described above, in the method of manufacturing the physical quantity sensor 1 of the present embodiment, the step of etching the silicon substrate 30 (dry etching step S3) includes the step of disposing the hard mask HM (mask) on the silicon substrate 30, and the hard mask. Etching the silicon substrate 30 via HM. In addition, the hard mask HM includes a sensor element region HM1 that overlaps a region that becomes the sensor element 3 of the silicon substrate 30, a first conductor portion region HM5 that overlaps a region that becomes the first conductor portion 55 of the silicon substrate 30, and the silicon substrate 30. The second conductor portion region HM6 that overlaps the region that becomes the second conductor portion 56, and the gap region HM8 that is located between the first conductor portion region HM5 and the second conductor portion region HM6. The etching rates of the gap regions HM8 and HM9 are faster than the etching rates of the sensor element region HM1, the first conductor portion region HM5, and the second conductor portion region HM6. Thus, during the dry etching, the gap region HM8 can be removed while leaving the sensor element region HM1, the first conductor portion region HM5, and the second conductor portion region HM6. The time T2 at which the etching of the region between the first conductor portion 55 and the second conductor portion 56 is started can be delayed from the time T1 at which the etching of the region around the sensor element 3 is started.

  As mentioned above, although the manufacturing method of the physical quantity sensor of this invention was demonstrated based on embodiment of illustration, this invention is not limited to this, The structure of each part is set to the thing of the arbitrary structures which have the same function. Can be replaced. In addition, any other component may be added to the present invention. Moreover, you may combine embodiment mentioned above suitably.

  In the above-described embodiment, the configuration in which the physical quantity sensor detects the acceleration in the X-axis direction has been described. However, the configuration is not limited to this, and the configuration in which the acceleration in the Y-axis direction is detected may be used. The structure which detects the acceleration of may be sufficient. In the above-described embodiment, the configuration in which the physical quantity sensor detects acceleration has been described. However, the physical quantity detected by the physical quantity sensor is not particularly limited, and may be, for example, an angular velocity. Further, the physical quantity sensor may be capable of detecting a plurality of physical quantities. A plurality of physical quantities are the same kind of physical quantities with different detection axes (for example, acceleration in the X-axis direction, acceleration in the Y-axis direction, acceleration in the Z-axis direction, angular velocity around the X axis, angular velocity around the Y axis, and Z Angular velocity around the axis) or different physical quantities (for example, angular velocity around the X axis and acceleration in the X axis direction).

  In addition, the physical quantity sensor 1 manufactured by the manufacturing method of the physical quantity sensor of this invention can be mounted in the following apparatuses, for example.

  FIG. 25 is a cross-sectional view showing a physical quantity sensor device equipped with a physical quantity sensor. As shown in the figure, the physical quantity sensor device 5000 includes a physical quantity sensor 1, a semiconductor element 5900 (circuit element), and a package 5100 that houses the physical quantity sensor 1 and the semiconductor element 5900.

  The package 5100 includes a cavity-shaped base 5200 and a lid 5300 bonded to the upper surface of the base 5200. The base 5200 has a recess 5210 that opens on the upper surface thereof. In addition, the recess 5210 has a first recess 5211 that opens to the top surface of the base 5200 and a second recess 5212 that opens to the bottom surface of the first recess 5211.

  On the other hand, the lid 5300 has a plate shape and is joined to the upper surface of the base 5200 so as to close the opening of the recess 5210. Thus, the storage space S ′ is formed in the package 5100 by closing the opening of the recess 5210 with the lid 5300, and the physical quantity sensor 1 and the semiconductor element 5900 are stored in the storage space S ′. In addition, it does not specifically limit as a joining method of the base 5200 and the cover body 5300, In this embodiment, the seam welding via the seam ring 5400 is used.

  The storage space S ′ is hermetically sealed. The atmosphere of the storage space S ′ is not particularly limited. For example, the atmosphere of the storage space S of the physical quantity sensor 1 is preferably the same. Thereby, even if the airtightness of the storage space S collapses and the storage spaces S and S ′ communicate with each other, the atmosphere of the storage space S can be maintained as it is. Therefore, a change in detection characteristics of the physical quantity sensor 1 due to a change in the atmosphere of the storage space S can be suppressed, and stable detection characteristics can be exhibited.

  A constituent material of the base 5200 is not particularly limited, and for example, various ceramics such as alumina, zirconia, and titania can be used. The constituent material of the lid 5300 is not particularly limited, but may be a member whose linear expansion coefficient approximates that of the constituent material of the base 5200. For example, when the constituent material of the base 5200 is a ceramic as described above, an alloy such as Kovar is preferably used.

  The base 5200 has a plurality of internal terminals 5230 disposed in the storage space S ′ (the bottom surface of the first recess 5211) and a plurality of external terminals 5240 disposed on the bottom surface. Each internal terminal 5230 is electrically connected to a predetermined external terminal 5240 via an internal wiring (not shown) disposed in the base 5200.

  The physical quantity sensor 1 is fixed to the bottom surface of the recess 5210 via the die attach material DA, and the semiconductor element 5900 is disposed on the top surface of the physical quantity sensor 1 via the die attach material DA. The physical quantity sensor 1 and the semiconductor element 5900 are electrically connected via the bonding wire BW1, and the semiconductor element 5900 and the internal terminal 5230 are electrically connected via the bonding wire BW2.

  The semiconductor element 5900 includes, for example, a drive circuit that applies a drive voltage to the sensor element 3, a detection circuit that detects acceleration Ax based on an output from the sensor element 3, and a signal from the detection circuit as a predetermined signal. An output circuit that converts the data into an output and the like are included as necessary.

  FIG. 26 is a perspective view showing a personal computer equipped with a physical quantity sensor. As shown in the figure, a personal computer 1100 includes a main body 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display 1108. The display unit 1106 is a hinge structure portion with respect to the main body 1104. It is supported so that rotation is possible. The personal computer 1100 includes a physical quantity sensor 1 and a control circuit 1110 (control unit) that performs control based on a detection signal output from the physical quantity sensor 1. As the physical quantity sensor 1, for example, any one of the above-described embodiments can be used.

  FIG. 27 is a perspective view showing a mobile phone equipped with a physical quantity sensor. As shown in the figure, the cellular phone 1200 includes an antenna (not shown), a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and a display is provided between the operation buttons 1202 and the earpiece 1204. Part 1208 is arranged. The mobile phone 1200 includes a physical quantity sensor 1 and a control circuit 1210 (control unit) that performs control based on the detection signal output from the physical quantity sensor 1.

  FIG. 28 is a perspective view showing a digital still camera equipped with a physical quantity sensor. As shown in the figure, the digital still camera 1300 includes a case 1302, and a display unit 1310 is provided on the back of the case 1302. The display unit 1310 is configured to perform display based on an imaging signal from the CCD, and functions as a finder that displays the subject as an electronic image. A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (the back side in the drawing) of the case 1302. When the photographer confirms the subject image displayed on the display unit 1310 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308. The digital still camera 1300 includes a physical quantity sensor 1 and a control circuit 1320 (control unit) that performs control based on a detection signal output from the physical quantity sensor 1. The physical quantity sensor 1 is used for camera shake correction, for example.

  FIG. 29 is a perspective view showing an automobile equipped with a physical quantity sensor. As shown in the figure, the automobile 1500 includes a system 1510 of at least one of an engine system, a brake system, and a keyless entry system. In addition, the physical quantity sensor 1 is built in the automobile 1500, and the detection signal of the physical quantity sensor 1 is supplied to the control device 1502, and the control device 1502 can control the system 1510 based on the signal.

  Such an automobile 1500 (moving body) includes the physical quantity sensor 1 and a control device 1502 (control unit) that performs control based on a detection signal output from the physical quantity sensor 1. Therefore, the effect of the physical quantity sensor 1 described above can be enjoyed and high reliability can be exhibited.

  In addition, the physical quantity sensor 1 includes a car navigation system, a car air conditioner, an anti-lock brake system (ABS), an air bag, a tire pressure monitoring system (TPMS), an engine control, and a hybrid vehicle. It can be widely applied to electronic control units (ECU) such as battery monitors for electric vehicles and electric vehicles.

  As mentioned above, although the apparatus which mounted the physical quantity sensor 1 was demonstrated, the apparatus which mounts the physical quantity sensor 1 is not limited to this, For example, a smart phone, a tablet terminal, a clock (including a smart watch), an inkjet -Type discharge device (for example, inkjet printer), laptop personal computer, TV, wearable terminal such as HMD (head mounted display), video camera, video tape recorder, car navigation device, pager, electronic notebook (including communication function) ), Electronic dictionary, calculator, electronic game device, word processor, workstation, video phone, security TV monitor, electronic binoculars, POS terminal, medical device (eg, electronic thermometer, sphygmomanometer, blood glucose meter, electrocardiogram measuring device, ultrasound) Diagnostic equipment Electronic endoscope), fish detector, various measuring equipment, mobile terminal base station equipment, instruments (eg, vehicles, aircraft, ship instruments), flight simulator, network server, airplane, rocket, artificial satellite, It can also be mounted on unmanned airplanes such as ships, AGVs (automated guided vehicles), bipedal walking robots, and drones.

  DESCRIPTION OF SYMBOLS 1 ... Physical quantity sensor, 10 ... Cover, 100 ... Silicon substrate, 11 ... Concave part, 19 ... Glass frit, 2 ... Substrate, 20 ... Glass substrate, 21 ... Concave part, 25 ... Groove part, 251 ... Convex part, 26 ... Groove part, 261 ... convex portion, 27 ... groove portion, 271 ... convex portion, 3 ... sensor element, 3A ... movable structure, 3B ... first fixed structure, 3C ... second fixed structure, 30 ... silicon substrate, 300 ... region, 31, 32 ... fixed part, 33 ... movable part, 34 and 35 ... spring part, 36 ... movable electrode finger, 37 ... first fixed electrode finger, 38 ... second fixed electrode finger, 5 ... conductor part, 55 ... first Conductor part, 550 ... area, 56 ... second conductor part, 560 ... area, 57 ... third conductor part, 570 ... area, 75 ... wiring, 76 ... wiring, 77 ... wiring, 1100 ... personal computer, 1102 ... keyboard, 1104 ... main body 1106 ... Display unit, 1108 ... display unit, 1110 ... control circuit, 1200 ... mobile phone, 1202 ... operation button, 1204 ... earpiece, 1206 ... mouthpiece, 1208 ... display unit, 1210 ... control circuit, 1300 ... digital still camera, 1302 ... Case, 1304 ... Light receiving unit, 1306 ... Shutter button, 1308 ... Memory, 1310 ... Display unit, 1320 ... Control circuit, 1500 ... Automobile, 1502 ... Control device, 1510 ... System, 5000 ... Physical quantity sensor device, 5100 ... Package 5200 ... Base 5210 ... Recess, 5211 ... First recess, 5212 ... Second recess, 5230 ... Internal terminal, 5240 ... External terminal, 5300 ... Cover, 5400 ... Seam ring, 5900 ... Semiconductor element, Ax ... Acceleration, BW1 ... Bonding wire, W2 ... bonding wire, DA ... die attach material, HM ... hard mask, HM1 ... sensor element region, HM5 ... first conductor portion region, HM6 ... second conductor portion region, HM7 ... third conductor portion region, HM8, HM9, HM10 ... Gap area, K ... Divided area, L ... Scribe line, P ... Connection pad, R1, R2 ... Part, S ... Storage space, S '... Storage space, S1 ... Preparation process, S2 ... Join process, S3 ... Dry etching process, S4 ... Lid joining process, S5 ... Dividing process, V1 ... Voltage

Claims (10)

Bonding the substrate to be processed to the substrate;
Etching the substrate to be processed, and forming a sensor element and a conductor portion from the substrate to be processed.
The sensor element is
A movable structure displaceable with respect to the substrate;
A first fixed structure fixed to the substrate and separated from the movable structure,
The conductor portion is
A first conductor portion electrically connected to the movable structure;
A second conductor portion disposed apart from the first conductor portion and electrically connected to the first fixed structure,
In the step of etching the substrate to be processed, the time at which etching of the region between the first conductor portion and the second conductor portion is started is earlier than the time at which etching of the region around the sensor element is started. A method of manufacturing a physical quantity sensor characterized by being slower. The step of etching the substrate to be processed includes:
Placing a mask on the substrate to be processed;
Etching the substrate to be processed through the mask, and
The mask is
A sensor element region overlapping with a region to be the sensor element of the substrate to be processed;
A first conductor portion region overlapping with a region to be the first conductor portion of the substrate to be processed;
A second conductor portion region that overlaps with the second conductor portion region of the substrate to be processed;
A gap region located between the first conductor portion region and the second conductor portion region,
2. The method of manufacturing a physical quantity sensor according to claim 1, wherein a thickness of the gap region is smaller than thicknesses of the sensor element region, the first conductor portion region, and the second conductor portion region. The step of etching the substrate to be processed includes:
Placing a mask on the substrate to be processed;
Etching the substrate to be processed through the mask, and
The mask is
A sensor element region overlapping with a region to be the sensor element of the substrate to be processed;
A first conductor portion region overlapping with a region to be the first conductor portion of the substrate to be processed;
A second conductor portion region that overlaps with the second conductor portion region of the substrate to be processed;
A gap region located between the first conductor portion region and the second conductor portion region,
2. The physical quantity sensor manufacturing method according to claim 1, wherein an etching rate of the gap region is faster than an etching rate of the sensor element region, the first conductor portion region, and the second conductor portion region.   4. The method of manufacturing a physical quantity sensor according to claim 2, wherein the gap region of the mask is removed during the step of etching the substrate to be processed through the mask.   The sensor element region, the first conductor portion region, and the second conductor portion region of the mask remain until the sensor element, the first conductor portion, and the second conductor portion are formed. The manufacturing method of the physical quantity sensor of any one of thru | or 4. A first wiring disposed on the substrate and electrically connecting the movable structure and the first conductor portion;
The physical quantity sensor according to claim 1, further comprising: a second wiring disposed on the substrate and electrically connecting the first fixed structure and the second conductor portion. Production method. The sensor element has a second fixed structure fixed to the substrate and separated from the movable structure and the first fixed structure;
The conductor portion is disposed apart from the first conductor portion and the second conductor portion, and has a third conductor portion electrically connected to the second fixed structure,
The mask has a third conductor portion region that overlaps a region that becomes the third conductor portion of the substrate to be processed, and the gap region is also formed between the first conductor portion region and the third conductor portion region. The method for producing a physical quantity sensor according to any one of claims 2 to 5, further comprising: The movable structure is
A movable part displaceable in a first direction with respect to the substrate;
A movable electrode finger provided in the movable part and having a longitudinal shape along a second direction intersecting the first direction;
The first fixed structure has a longitudinal shape along the second direction, is located on one side of the first direction with respect to the movable electrode finger, and faces the movable electrode finger through a gap. Having a first fixed electrode finger,
The second fixed structure has a longitudinal shape along the second direction, is located on the other side of the first direction with respect to the movable electrode finger, and faces the movable electrode finger via a gap. The method of manufacturing a physical quantity sensor according to claim 7, further comprising a second fixed electrode finger. It is performed after forming the sensor element and the conductor portion, and includes a step of bonding a lid to the substrate so as to cover the sensor element,
The method of manufacturing a physical quantity sensor according to claim 1, wherein the conductor portion is located outside the lid.   The method for manufacturing a physical quantity sensor according to any one of claims 1 to 9, further comprising a step of removing the conductor portion, which is performed after forming the sensor element and the conductor portion.

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