JP2018201184A - Mems element, electronic apparatus, and movable body - Google Patents

Abstract

To provide an MEMS element excellent in reliability, an electronic apparatus including the MEMS element, and a movable body.SOLUTION: In an MEMS element 1 has element adjustment layers 30 disposed between a surface silicon layer 13 and electrode pads 50; the element adjustment layers 30 respectively have first through holes 51 disposed at positions overlapping the electrode pads 50 in plan view; the surface silicon layer 13 has second through holes 52 communicating with the first through holes 51 at positions overlapping the electrode pads 50 in plan view; a silicon layer 11 and a BOX layer 12 have third through holes 54 communicating with the second through holes 52 at positions overlapping the electrode pads 50 in plan view; the opening width W3 of the first through hole 51 is smaller than the opening width W4 of the second through hole 52; and wiring electrodes 56, 58 conducting with the electrode pads 50 are disposed in the first through holes 51, second through holes 52, and third through holes 54.SELECTED DRAWING: Figure 2A

Description

  The present invention relates to a MEMS element, an electronic device including the MEMS element, and a moving body.

  2. Description of the Related Art Conventionally, a MEMS vibrator in which an operating element is formed on a silicon substrate using a MEMS technique is known. For example, in Patent Document 1 below, a working space (internal space) of a working element of a silicon substrate (element substrate) on which a working element is formed is also formed of a silicon substrate, and a through-hole electrode (TSV: A method of manufacturing a MEMS vibrator by joining a lid substrate provided with “Through Silicon Via”, vacuum-sealing (depressurizing sealing), and separating into pieces is disclosed.

Japanese Patent Laid-Open No. 2006-171393

However, in the MEMS vibrator described in Patent Document 1, there is an advanced processing method for processing the joint surface of the lid substrate provided with the through-hole electrode into a uniform surface without unevenness in order to vacuum seal the working space. There was a problem that it was necessary.
Further, in order to collectively seal the element substrate and the lid substrate in a vacuum atmosphere (reduced pressure atmosphere), there is a problem that the technical difficulty is high, the apparatus becomes large, and the manufacturing cost increases.

  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 application examples or forms.

  Application Example 1 A MEMS element according to this application example includes an element substrate having an element, an element electrode for driving the element, and a support substrate that supports the element substrate. An electrode pad disposed on the substrate and connected to the element electrode is provided, and an element adjustment layer is disposed between the element substrate and the electrode pad. The element adjustment layer overlaps the electrode pad in plan view. A first through hole is disposed at a position, and a second through hole communicating with the first through hole is disposed at a position overlapping the electrode pad in plan view on the element substrate, and the support The substrate is provided with a third through hole communicating with the second through hole at a position overlapping the electrode pad in plan view, and the opening width of the first through hole is the second through hole. Smaller than the opening width of the first through hole, the second through hole, and the first through hole. The through-hole, wherein the wiring electrode is electrically connected to the electrode pads are disposed.

  According to this application example, the first through hole, the second through hole, and the third through hole are disposed at a position overlapping the electrode pad, and the first through hole, the second through hole, and the third through hole are disposed. Since the wiring electrode that is electrically connected to the electrode pad is disposed in the through hole, it can be easily electrically connected to the element electrode on the surface of the element substrate opposite to the element formed side. Therefore, a highly reliable MEMS element can be obtained without requiring an advanced processing method. In addition, since the opening width of the first through hole is smaller than the opening width of the second through hole, the area of the element adjustment layer that supports the electrode pad can be increased, and the strength of the electrode pad can be improved. Can do.

  Application Example 2 In the MEMS element according to the application example described above, the element adjustment layer disposed at a position overlapping the second through hole in a plan view extends to the second through hole in a cross sectional view. It is preferable that

  According to this application example, since the element adjustment layer constituting the first through hole extends to the second through hole, the thickness of the element adjustment layer supporting the electrode pad is increased, and the strength of the electrode pad is increased. Can be further improved.

  Application Example 3 In the MEMS element according to the application example described above, it is preferable that there are a plurality of the first through holes, and the first through holes are separated from each other by a partition wall.

  According to this application example, since the plurality of first through holes are separated from each other by the partition configured by the element adjustment layer, the strength of the electrode pad is improved by the partition, and the plurality of first through holes are Conductivity between the electrode pad and the wiring electrode can be achieved, and a highly reliable MEMS element can be obtained.

  Application Example 4 In the MEMS element according to the application example described above, it is preferable that three or more of the partition walls have a structure that intersects at one point.

  According to this application example, since three or more barrier ribs have a structure intersecting at one point, the strength of the barrier ribs composed of the element adjustment layer that supports the electrode pads is improved, and the strength of the electrode pads is increased. It can be improved further.

  Application Example 5 A MEMS element according to this application example includes an element substrate having an element, an element electrode for driving the element, and a support substrate that supports the element substrate. An electrode pad disposed on the substrate and connected to the element electrode is provided, and an element adjustment layer is disposed between the element substrate and the electrode pad. The element adjustment layer overlaps the electrode pad in plan view. A first through hole is disposed at a position, and a second through hole communicating with the first through hole is disposed at a position overlapping the electrode pad in plan view on the element substrate, and the support The substrate is provided with a third through hole communicating with the second through hole at a position overlapping the electrode pad in plan view, and the opening width of the first through hole and the second through hole is as follows. , Smaller than the opening width of the third through hole, the first through hole, the first The through-hole and the third through hole of, wherein the wiring electrode is electrically connected to the electrode pads are disposed.

  According to this application example, the first through hole, the second through hole, and the third through hole are disposed at a position overlapping the electrode pad, and the first through hole, the second through hole, and the third through hole are disposed. Since the wiring electrode that is electrically connected to the electrode pad is disposed in the through hole, the element electrode can be easily electrically connected to the surface of the element substrate opposite to the side where the element is formed. Therefore, a highly reliable MEMS element can be obtained without requiring an advanced processing method. In addition, since the opening widths of the first through hole and the second through hole are smaller than the opening width of the third through hole, the element adjustment layer that supports the electrode pad and the element substrate that constitutes the second through hole , The strength of supporting the electrode pad can be improved, and the strength of the electrode pad can be improved.

  Application Example 6 In the MEMS element according to the application example described above, the element adjustment layer and the element substrate each include the first through hole and the second through hole having overlapping portions in plan view. It is preferable to have.

  According to this application example, the first through hole formed by the element adjustment layer and the second through hole formed by the element substrate have a portion that overlaps in a plan view. While improving the strength, electrical connection between the electrode pad and the wiring electrode can be achieved, and a highly reliable MEMS element can be obtained.

  Application Example 7 An electronic apparatus according to this application example includes the MEMS element described in the application example.

  According to this application example, a highly efficient electronic device can be provided by utilizing a highly reliable MEMS element in the electronic device.

  Application Example 8 A moving object according to this application example includes the MEMS element described in the application example.

  According to this application example, a high-performance moving body can be provided by utilizing a highly reliable MEMS element for the moving body.

1 is a schematic plan view showing a configuration of a MEMS element according to a first embodiment. The schematic sectional drawing in the P1-P1 line | wire of FIG. The enlarged view which shows the Q1 part of FIG. 2A. The enlarged view which shows Q2 part of FIG. 2A. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 1st Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on this embodiment. The schematic plan view in R1 of FIG. 1 which shows the structure of the modification 1 of the MEMS element which concerns on 1st Embodiment. The schematic plan view in R1 of FIG. 1 which shows the structure of the modification 2 of the MEMS element which concerns on 1st Embodiment. The schematic plan view in R1 of FIG. 1 which shows the structure of the MEMS element which concerns on 2nd Embodiment. The schematic sectional drawing in the P2-P2 line | wire of FIG. 5A. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 2nd Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 2nd Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 2nd Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 2nd Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 2nd Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 2nd Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 2nd Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 2nd Embodiment. The schematic plan view in R1 of FIG. 1 which shows the structure of the MEMS element which concerns on 3rd Embodiment. The schematic sectional drawing in the P3-P3 line | wire of FIG. 7A. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 3rd Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 3rd Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 3rd Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 3rd Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 3rd Embodiment. The schematic sectional drawing equivalent to the position of the P1-P1 line | wire of FIG. 1 which shows the manufacturing process of the MEMS element which concerns on 3rd Embodiment. The perspective view which shows the structure of the mobile type (or notebook type) personal computer as an electronic device provided with the MEMS element of this invention. The perspective view which shows the structure of the mobile telephone as an electronic device provided with the MEMS element of this invention. The perspective view which shows the structure of the digital camera as an electronic device provided with the MEMS element of this invention. The perspective view which shows the structure of the motor vehicle as a moving body provided with the MEMS element of this invention.

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention. In the following drawings, the scale may be different from the actual scale for easy understanding.

(First embodiment)
[MEMS element]
First, the MEMS element 1 according to the first embodiment will be described with reference to FIGS. 1, 2A, 2B, and 2C.
FIG. 1 is a schematic plan view showing the configuration of the MEMS element 1 according to the first embodiment, FIG. 2A is a schematic cross-sectional view taken along line P1-P1 shown in FIG. 1, and FIG. 2B is a diagram of Q1 in FIG. FIG. 2C is an enlarged view of a portion Q2 in FIG. 2A. In FIG. 1, for the convenience of explaining the internal configuration of the MEMS element 1, a state in which the lid 5 is removed is illustrated. In FIGS. 2A, 2B, and 2C, a line indicating the background of the cross section is omitted.

As shown in FIGS. 1, 2A, 2B, and 2C, the MEMS element 1 according to the present embodiment includes a lid 5 for hermetically sealing the element 20, and an SOI (Silicon on Insulator) substrate 10.
The lid 5 is made of single crystal silicon or the like, and has a cavity 7 that opens to the SOI substrate 10 side. The surface of the lid 5 on which the cavity 7 is provided is bonded to the surface of the SOI substrate 10 on which the element 20 is formed.

The SOI substrate 10 is a substrate in which a silicon layer 11, a BOX (Buried Oxide) layer 12, and a surface silicon layer 13 are laminated in this order. For example, the silicon layer 11 and the surface silicon layer 13 are made of single crystal silicon, and the BOX layer 12 is made of a silicon oxide layer (SiO ₂ or the like). In the present embodiment, the silicon layer 11 and the BOX layer 12 correspond to a support substrate, and the surface silicon layer 13 corresponds to an element substrate.

  The SOI substrate 10 is connected to an element 20 made of silicon of the surface silicon layer 13, an electrode pad 50 formed on the surface silicon layer 13, and an element electrode and an electrode pad 50 for driving the element 20. A plurality of wirings 46 (see FIG. 2A, not shown in FIG. 1), wiring electrodes 56 and 58 for drawing electrodes on the surface opposite to the side where the element 20 is formed connected to the electrode pad 50; An internal space constituted by the second through hole 52 and the third through hole 54 for forming the wiring electrodes 56 and 58, the cavity 7 of the lid 5, and the cavity 8 formed in the SOI substrate 10. A first sealing hole 60 and a second sealing hole 62 for hermetically sealing are provided.

The element 20 includes a base portion 21 supported by the BOX layer 12 and a vibrating portion 22 separated from surrounding silicon other than the base portion 21 by a groove 13a on the region where the BOX layer 12 is removed. The element 20 exemplified in the present embodiment has three vibrating portions 22. A cavity 8 constituting an internal space is provided in the silicon layer 11 and the BOX layer 12 at a position facing the vibrating portion 22.
Further, on the surface of the element 20 on the lid 5 side, an element adjustment layer 30 that is a silicon oxide film disposed in a predetermined region of the element 20 and a piezoelectric drive unit 40 that covers at least a part of the element adjustment layer 30. And are provided.

  The element adjustment layer 30 is provided to correct the temperature characteristic of the resonance frequency of the vibration unit 22. Silicon has a resonance frequency that decreases as the temperature increases, while silicon oxide has a resonance frequency that increases as the temperature increases. Therefore, by disposing the element adjustment layer 30 that is a silicon oxide film on the silicon element 20, the temperature characteristic of the resonance frequency of the complex composed of the vibration part 22 of the element 20 and the element adjustment layer 30 is flattened. Can approach. A plurality of first through holes 51 are provided at positions overlapping the electrode pads 50.

The piezoelectric drive unit 40 includes a polysilicon film 41, a first electrode 42, a piezoelectric layer 43, and a second electrode 44. In the present embodiment, the first electrode 42 and the second electrode 44 correspond to element electrodes.
The polysilicon film 41 is made of polysilicon not doped with impurities, and may be made of amorphous silicon, for example. In the present embodiment, the polysilicon film 41 is provided so as to cover the element adjustment layer 30 disposed on the element 20. As described above, since the element adjustment layer 30 exists between the polysilicon film 41 and the element 20, the polysilicon film 41 protects the element adjustment layer 30 from etching of the silicon oxide film around the piezoelectric driving unit 40. be able to.

  The first electrode 42 and the second electrode 44 are arranged so as to sandwich the piezoelectric layer 43. In the example shown in the present embodiment, three sets of the first electrode 42, the piezoelectric layer 43, and the second electrode 44 are disposed corresponding to the three vibrating portions 22.

  The plurality of wirings 46 are electrically connected to the first electrode 42 and the second electrode 44 so as to vibrate adjacent vibrating portions 22 in opposite phases. Further, the plurality of wirings are electrically connected to the electrode pad 50, and by applying a voltage from the outside via the wiring electrodes 56 and 58 between the two electrode pads 50, the adjacent vibrating parts 22 are vibrated in opposite phases. be able to.

  As a material constituting them, for example, the piezoelectric layer 43 is made of aluminum nitride (AlN) or the like, and the first electrode 42 and the second electrode 44 are made of titanium nitride (TiN) or the like. The plurality of wirings 46 and the electrode pads 50 are made of aluminum (Al) or copper (Cu).

  When a voltage is applied between the first electrode 42 and the second electrode 44 via the two electrode pads 50, the piezoelectric layer 43 expands and contracts, and the vibration unit 22 vibrates. The vibration is greatly excited at the natural resonance frequency, and the impedance is minimized. As a result, by connecting the MEMS element 1 to an oscillation circuit, the MEMS element 1 oscillates at an oscillation frequency mainly determined by the resonance frequency of the vibration unit 22.

As shown in FIG. 1, one electrode pad 50 is disposed on each side of the element 20 in the region of the cavity 7 of the lid 5 in plan view. The element adjustment layer 30 is provided with a first through hole 51 at a position overlapping the electrode pad 50 in a plan view, and the surface silicon layer 13 serving as an element substrate is positioned at a position overlapping the electrode pad 50 in a plan view. The second through-hole 52 communicating with the first through-hole 51 is provided, and the second through-hole is formed in the silicon layer 11 and the BOX layer 12 serving as the support substrate at a position overlapping the electrode pad 50 in plan view. A third through hole 54 that communicates with the hole 52 is provided.
The opening width W3 of the first through hole 51 is smaller than the opening width W4 of the second through hole 52. Therefore, the area of the element adjustment layer 30 that supports the electrode pad 50 can be increased. The strength of the pad 50 can be improved.

  In addition, the electrode pad 50 is arranged in the first through hole 51, the second through hole 52, and the third through hole 54 at a position overlapping the second through hole 52 in plan view. , 58 are electrically connected to each other through the wiring 46, and at a position not overlapping the second through hole 52, the element adjustment layer 30, the polysilicon film 41, and the wiring 46 are formed on the surface silicon layer 13. It is arranged via. Therefore, the electrode pad 50 and the wiring electrodes 56 and 58 are electrically connected, and the first electrode 42 and the second electrode 44 are surfaces opposite to the side on which the element 20 of the SOI substrate 10 is formed. Can be pulled out. The material constituting the wiring electrodes 56 and 58 is composed of titanium (Ti), tungsten (W), copper (Cu), etc., and the wiring electrode 56 is a sputtered layer formed by sputtering, The electrode 58 is a plating layer formed by a plating method, and the plating layer (wiring electrode 58) is laminated on the sputter layer (wiring electrode 56).

  The first sealing hole 60 and the second sealing hole 62 are arranged in the area of the cavity 7 of the lid 5 on the side facing the side where the vibration part 22 of the base 21 is provided in plan view. It is installed. The first sealing hole 60 is disposed on the surface silicon layer 13 at a position overlapping the second sealing hole 62. The second sealing hole 62 communicates with the first sealing hole 60 and is disposed in the silicon layer 11 and the BOX layer 12.

A plurality of first sealing holes 60 are disposed at positions where the opening width W 1 is smaller than the opening width W 2 of the second sealing hole 62 and overlaps with the second sealing hole 62. Therefore, since the opening width W2 of the second sealing hole 62 is larger than the opening width W1 of the first sealing hole 60, the sealing film that closes the first sealing hole 60 from the second sealing hole 62 side. As a result, the wiring electrode 56 to be reached easily reaches the first sealing hole 60, and sealing becomes easy. In addition, in the first sealing hole 60, a wiring electrode 56 made of a sputtered layer, that is, the same metal layer as the wiring electrode 56 is disposed, and formed in the cavity 7 of the lid 5 and the SOI substrate 10. An internal space constituted by the cavity 8 is hermetically sealed.
In the second sealing hole 62, a wiring electrode 56 made of a sputter layer is provided, and a wiring electrode 58 made of a plating layer laminated on the wiring electrode 56 is provided. In the present embodiment, the two first sealing holes 60 are provided, but the present invention is not limited to this, and one or more may be used.

  As described above, according to the MEMS element 1 according to the present embodiment, the first through hole 51, the second through hole 52, and the third through hole 54 are disposed at positions overlapping the electrode pad 50, Since the first through hole 51, the second through hole 52, and the third through hole 54 are provided with wiring electrodes 56 and 58 that are electrically connected to the electrode pad, the element of the surface silicon layer 13 as an element substrate The first electrode 42 and the second electrode 44 can be easily electrically connected to the surface opposite to the side on which 20 is formed. Therefore, the MEMS element 1 excellent in reliability can be obtained without requiring an advanced processing method. Further, since the opening width W3 of the first through hole 51 is smaller than the opening width W4 of the second through hole 52, the area of the element adjustment layer 30 that supports the electrode pad 50 can be increased, and the electrode pad The strength of 50 can be improved.

[Production method]
Next, the manufacturing process of the MEMS element 1 according to the present embodiment will be described with reference to FIGS. 3A to 3R.
3A to 3R are schematic cross-sectional views corresponding to the position of the P1-P1 line in FIG. 1 showing the manufacturing process of the MEMS element 1 according to the present embodiment. Note that a line indicating the background of the cross section is omitted.

  First, as a preparation process, a lid 5 having an SOI substrate 10 and a cavity 7 in which a silicon layer 11, a BOX layer 12, and a surface silicon layer 13 are laminated in this order is prepared (see FIG. 2A). The SOI substrate 10 may be manufactured by forming the BOX layer 12 on the silicon layer 11 and forming the surface silicon layer 13 on the BOX layer 12.

  In the first step, as shown in FIG. 3A, a trench is formed in the surface silicon layer 13 of the SOI substrate 10 to separate a region that becomes the vibrating portion 22 of the element 20 from surrounding silicon other than a region that becomes the base portion 21 of the element 20. 13b, a trench 51b and a first sealing hole 60 for providing the first through hole 51 in the element adjustment layer 30 are formed. At that time, a slit 13 c may be formed in a region separated from the vibrating portion 22 of the element 20 by the trench 13 b of the surface silicon layer 13 of the SOI substrate 10. Thereby, in the region where the width of the groove 13a (see FIG. 1) is wide, it is possible to facilitate the release etching of silicon around the vibrating portion 22 that is performed later.

  The trench 13b, the trench 51b and the first sealing hole 60 are formed by applying a resist 14 on the surface silicon layer 13, forming a mask pattern by photolithography, and etching the surface silicon layer 13 using the resist 14 as a mask. 3A, in the surface silicon layer 13, the trench 13b that separates the region that becomes the vibrating portion 22 of the element 20 from the surrounding silicon other than the region that becomes the base 21 of the element 20, the first penetration A trench 51b in which the hole 51 is provided and a first sealing hole 60 are formed. The surface of the surface silicon layer 13 of the SOI substrate 10 is thermally oxidized to form a silicon oxide film, a mask made of the silicon oxide film is formed by a photolithography method, and the surface silicon layer 13 is etched to form a trench. 13b, the trench 51b, and the first sealing hole 60 may be formed.

  In the second step, as shown in FIG. 3B, an element adjustment layer 30 that is a silicon oxide film is formed on the upper surface of the surface silicon layer 13, the trench 13b, the trench 51b, and the side walls in the first sealing hole 60. . For example, by thermally oxidizing the surface silicon layer 13 of the SOI substrate 10, a thermal oxide film (silicon oxide film) is formed on the upper surface of the surface silicon layer 13, the trench 13 b, the trench 51 b, and the side walls in the first sealing hole 60. Is formed. The thickness of the thermal oxide film is, for example, about 0.3 μm to 1.2 μm, and may be adjusted according to desired temperature characteristics. This thermal oxide film serves as a protective wall that protects the vibrating portion 22 and the piezoelectric driving portion 40 from silicon release etching around the vibrating portion 22 that is performed later.

  Next, a silicon oxide film filling the trench 13b, the trench 51b, and the first sealing hole 60 of the surface silicon layer 13 is formed by a CVD (chemical vapor deposition) method. At this time, even if “soot” occurs in the silicon oxide film in the trench 13b, the trench 51b, and the first sealing hole 60, there is no problem because the thermal oxide film is strong. In addition, since the trench 13b, the trench 51b, and the first sealing hole 60 of the surface silicon layer 13 formed by processing are filled with the silicon oxide film and the surface becomes almost flat, a step to the subsequent photolithography process is performed. The adverse effect of can be eliminated.

  Therefore, the thermal oxide film formed by thermally oxidizing the surface silicon layer 13 and the silicon oxide film formed by the CVD method form the element adjustment layer 30 shown in FIG. 2A. In the second step, the element adjustment layer 30 may be formed of only a thermal oxide film depending on the degree of flatness. Alternatively, a silicon oxide film may be formed by a thermal CVD method without forming a thermal oxide film, and further, a silicon oxide film may be formed by a two-stage CVD method of a thermal CVD method and a plasma CVD method. May be.

  In the third step, a resist is applied on the element adjustment layer 30, and a predetermined region such as the element 20 including the first through hole 51, the first sealing hole 60, and the vibrating portion 22 is formed by photolithography. A trench reaching the surface silicon layer 13 is formed by forming a mask pattern for protecting the element and etching the element adjustment layer 30 using the resist as a mask. Thereafter, as shown in FIG. 3C, a polysilicon film 41 covering the upper surface of the element adjustment layer 30 and the sidewall of the trench is formed by a CVD method.

  In the fourth step, a resist is applied on the polysilicon film 41, a mask pattern is formed by photolithography, and the polysilicon film 41 is etched using the resist as a mask. As a result, as shown in FIG. 3D, the polysilicon film is formed in a predetermined region of the element 20 including the vibrating portion 22 and a region including the side surface of the element adjustment layer 30 formed in the predetermined region serving as the first through hole 51. 41 is formed.

  The polysilicon film 41 covers the element adjustment layer 30 between the element 20 and the thickness of the polysilicon film 41 is, for example, about 0.2 μm. Since the embedding property of the polysilicon film 41 by the CVD method is good, the wall of the strong polysilicon film 41 that protects the element adjustment layer 30 from the release etching of the silicon oxide film around the vibrating portion 22 and the piezoelectric driving portion 40 performed later. Can be formed with a small thickness.

  In the fifth step, as shown in FIG. 3E, the first electrode 42, the piezoelectric layer 43, and the second electrode 44 are arranged in this order on the polysilicon film 41 formed in a predetermined region of the element 20. And by photolithography. Note that the polysilicon film 41 to the second electrode 44 constitute a piezoelectric drive unit 40. When the first electrode 42 and the second electrode 44 are formed, the wiring 46 for connecting the first electrode 42 and the electrode pad 50 and the second electrode 44 and the electrode pad 50 are connected. Wiring 46 for forming is also formed at the same time.

  In the sixth step, a silicon oxide film 33 is formed on the SOI substrate 10 on which the piezoelectric driving unit 40 is formed by a CVD method. Thereafter, as shown in FIG. 3F, a mask pattern having an opening at which the electrode pad 50 is to be formed is formed by photolithography, and aluminum (Al) or copper (Cu) or the like is formed by sputtering using the silicon oxide film 33 as a mask. The electrode pad 50 is formed by forming a film at a position where the electrode pad 50 is to be formed.

  In the seventh step, as shown in FIG. 3G, a silicon oxide film 34 is formed by the CVD method on the SOI substrate 10 on which the electrode pad 50 and the silicon oxide film 33 are formed. Thereafter, a resist is applied on the silicon oxide film 34, a mask pattern is formed by photolithography, and the silicon oxide film 34 is etched using the resist as a mask. Thereby, as shown in FIG. 3G, a silicon oxide film 34 is formed in which a predetermined region corresponding to the trench 13b reaching the surface silicon layer 13 is opened.

  In the eighth step, as shown in FIG. 3H, a resist 16 is applied on the silicon oxide film 34, a mask pattern is formed by photolithography, and the silicon oxide film 34 corresponding to the trench 13b is formed using the resist 16 as a mask. Then, the element adjustment layer 30 and the BOX layer 12 are etched in this order. Accordingly, the depth reaching the silicon layer 11 in a shape surrounding the vibration unit 22 while leaving the silicon oxide film 34 and the element adjustment layer 30 protecting the vibration unit 22, the piezoelectric drive unit 40, and the electrode pad 50. Forming an opening.

  In the ninth step, as shown in FIG. 3I, after the resist 16 is removed, the silicon around the vibrating portion 22 is removed through the openings of the silicon oxide film 34, the element adjustment layer 30, the surface silicon layer 13, and the BOX layer 12. Etching (release etching). At this time, a part of the silicon of the silicon layer 11 is etched to form the cavity 8 in the silicon layer 11 below the vibration part 22. In the ninth step, wet etching is performed, and TMAH (tetramethylammonium hydroxide) is used as an etchant, for example.

  In the tenth step, as shown in FIG. 3J, the vibration part 22, the piezoelectric driving part 40, the electrode pad 50, the silicon oxide film 34 around the first sealing hole 60, the element adjustment layer 30 and the BOX layer 12 are formed. Etched (release etching). Thereby, the element adjustment layer 30 remains on the vibration part 22. In the tenth step, wet etching is performed, and for example, BHF (buffered hydrofluoric acid) is used as an etchant. Thereafter, the surface having the cavity 7 of the lid 5 is disposed on the surface (the upper surface of the surface silicon layer 13) on which the element 20 of the SOI substrate 10 is formed, and bonded. Examples of the bonding method include direct bonding performed by activating the bonding surface and a method using a bonding member such as low-melting glass.

  In the eleventh step, as shown in FIG. 3K, a third through hole 54 and a second sealing hole 62 are formed in the silicon layer 11 of the SOI substrate 10. The third through hole 54 and the second sealing hole 62 are formed by forming the etching mask layer 36 and then etching the silicon layer 11 of the SOI substrate 10 by photolithography. Although a resist film is used as the mask layer 36, a silicon oxide film obtained by thermally oxidizing the surface of the silicon layer 11 may be used.

  In the twelfth step, as shown in FIG. 3L, the BOX layer 12 of the SOI substrate 10 is etched, and the third through hole 54 is also formed in the BOX layer 12 constituting the support substrate. Thereafter, the element adjustment layer 30 in the trench 51 b and the first sealing hole 60 is etched, and the first through hole 51 is formed in the element adjustment layer 30 disposed at a position overlapping the electrode pad 50.

  In the thirteenth step, as shown in FIG. 3M, a film resist 18 is pasted on the mask layer 36, a pattern is formed to open the third through hole 54 by photolithography, and the surface silicon layer 13 is etched. The second through hole 52 is formed. Thereafter, the polysilicon film 41 in the first through hole 51 is removed by anisotropic dry etching such as reactive ion etching (RIE).

  In the fourteenth step, as shown in FIG. 3N, after removing the film resist 18, the surface of the mask layer 36 on the silicon layer 11, the first through hole 51, the second through hole 52, A silicon oxide film 32 is formed on the side walls in the third through hole 54, the first sealing hole 60, and the second sealing hole 62.

  In the fifteenth step, as shown in FIG. 3O, inside the first through hole 51, the second through hole 52, the third through hole 54, the first sealing hole 60, and the second sealing hole 62 The silicon oxide film 32 on the surface of the mask layer 36, the element adjustment layer 30, the wiring 46, and the polysilicon film 41 except for the side walls is removed by anisotropic dry etching such as reactive ion etching (RIE).

  In the sixteenth step, as shown in FIG. 3P, the polysilicon film 41 exposed in the first sealing hole 60 is etched in a vacuum (reduced pressure) atmosphere in a pretreatment chamber such as a sputtering apparatus, A through hole is formed in the polysilicon film 41 on the sealing hole 60. Thereafter, the internal space formed by the cavities 7 and 8 is set to a pressure equivalent to that of the pretreatment chamber, and a metal layer such as titanium (Ti), tungsten (W), or copper (Cu) that becomes the wiring electrode 56 by continuous treatment. Sputter.

  By this step, the wiring electrode 56 connected to the first electrode 42 and the second electrode 44 can be formed on the surface opposite to the side on which the element 20 is formed. Further, in this step, since the wiring electrode 56 closes the first sealing hole 60, the internal space formed by the cavities 7 and 8 in which the element 20 is formed is sealed in a vacuum atmosphere (reduced pressure atmosphere). be able to. Therefore, the wiring electrode 56 is formed in the first through hole 51, the second through hole 52, and the third through hole 54, and the first sealing hole 60 is closed with the wiring electrode 56 to hermetically seal the internal space. And the step of stopping can be performed simultaneously.

  In the seventeenth step, as shown in FIG. 3Q, a metal layer equivalent to the metal layer used for the wiring electrode 56 is laminated on the surface of the wiring electrode 56 by a plating method or the like to form the wiring electrode 58. By completely closing the first through hole 51, the second through hole 52, the third through hole 54, and the second sealing hole 62, the electrical conductivity and mechanical strength are improved and the reliability is improved. The wiring electrode 56 is a sputter layer, and the wiring electrode 58 is a plating layer.

  In the eighteenth step, as shown in FIG. 3R, the strength of the electrode pad 50 is improved by flattening the surface of the SOI substrate 10 opposite to the surface to which the lid portion 5 is bonded with a polishing apparatus or the like. And the MEMS element 1 excellent in reliability is completed.

[Modification]
Next, a modification of the MEMS element 1 according to the first embodiment will be described with reference to FIGS. 4A and 4B.
4A is a schematic plan view of R1 in FIG. 1 showing the configuration of the first modification of the MEMS element 1 according to the first embodiment, and FIG. 4B shows the second modification of the MEMS element 1 according to the first embodiment. It is a schematic plan view in R1 of FIG. 1 which shows a structure.

In Modification 1 and Modification 2 of the MEMS element 1 according to the first embodiment, as shown in FIGS. 4A and 4B, the shape of the first through hole 51 in the first embodiment is different.
As shown in FIG. 4A, the first through-hole 51aa in the first modification has a rectangular shape and is arranged so that the longitudinal directions intersect each other.
Further, as shown in FIG. 4B, the first through hole 51ab in the second modification is arranged so that three rectangles are connected at one point in the longitudinal direction.
By adopting the above configuration, as in the first embodiment, the strength of the electrode pad 50 can be improved, and the electrical connection between the electrode pad 50 and the wiring electrodes 56 and 58 can be achieved, and the MEMS is excellent in reliability. Element 1 can be obtained.

(Second Embodiment)
[MEMS element]
Next, a MEMS device 1a according to a second embodiment of the present invention will be described with reference to FIGS. 5A and 5B.
FIG. 5A is a schematic plan view of R1 in FIG. 1 showing the configuration of the MEMS element 1a according to the second embodiment, and FIG. 5B is a schematic cross-sectional view taken along line P2-P2 in FIG. 5A. In addition, it demonstrates centering around difference with embodiment mentioned above, the same code | symbol is attached | subjected to the same structure, The description is abbreviate | omitted about the same matter.

The MEMS element 1a according to the second embodiment is different from the first through hole 51 of the MEMS element 1 according to the first embodiment in the shape and configuration of the first through hole 51ac.
As shown in FIG. 5A, the first through hole 51ac of the MEMS element 1a of the present embodiment is disposed at a position overlapping the electrode pad 50 and the second through hole 52 in plan view, and is configured by the element adjustment layer 30. The partition wall 38 has a quadrangular or octagonal hole shape. That is, a rectangular hole shape or an octagonal hole shape is formed by a structure in which three partition walls 38 intersect at one point, and the partition walls 38 are separated from each other.

  Further, the first through hole 51ac is constituted by a partition wall 38 which is the element adjustment layer 30 embedded in the trench 51b provided to form the first through hole 51ac in the element adjustment layer 30. As shown to 5B, it is extended to the 2nd through-hole 52. As shown to FIG. Therefore, the thickness of the element adjustment layer 30 that supports the electrode pad 50 is increased, and the strength of the electrode pad 50 is improved. In the present embodiment, the first through-hole 51ac is configured by a structure in which the three partition walls 38 intersect at one point. However, the present invention is not limited to this, and three or more partition walls 38 are one. The first through hole 51ac may be configured with a structure that intersects at a point. By crossing three or more partition walls 38 at one point, the support strength of the electrode pad 50 is increased, and the strength of the electrode pad 50 can be further improved.

  As described above, according to the MEMS element 1a according to the present embodiment, the element adjustment layer 30 constituting the first through hole 51ac extends to the second through hole 52. The thickness of the supporting element adjustment layer 30 is increased, and the strength of the electrode pad 50 can be further improved.

  Further, since the plurality of first through holes 51ac are separated from each other by the partition wall 38 formed of the element adjustment layer 30, the plurality of first through holes 51ac are improved while the strength of the electrode pad 50 is improved by the partition wall 38. In this case, electrical connection between the electrode pad 50 and the wiring electrodes 56 and 58 can be achieved, and the MEMS element 1a having excellent reliability can be obtained.

  Further, since the three or more partition walls 38 have a structure intersecting at one point, the strength of the partition wall 38 constituted by the element adjustment layer 30 that supports the electrode pad 50 is improved, and the strength of the electrode pad 50 is increased. It can be improved further.

[Production method]
Next, the manufacturing process of the MEMS element 1a according to the second embodiment will be described with reference to FIGS. 6A to 6H.
6A to 6H are schematic cross-sectional views corresponding to the position of the line P1-P1 in FIG. 1 showing the manufacturing process of the MEMS element 1a according to the second embodiment. Note that a line indicating the background of the cross section is omitted. Note that the manufacturing process in the second embodiment is the same from the first process to the eleventh process (FIGS. 3A to 3K) of the manufacturing process in the first embodiment described above, and therefore the eleventh process (FIG. 3K). The subsequent steps will be described.

  In the eleventh step, as shown in FIG. 6A, the third through hole 54 and the second sealing hole 62 are formed by etching the silicon layer 11 of the SOI substrate 10 using the mask layer 36 as a mask.

  In the twelfth step, as shown in FIG. 6B, the BOX layer 12 of the SOI substrate 10 in the third through hole 54 and the second sealing hole 62 is etched, and then the exposed trench 51b and the first A part of the element adjustment layer 30 in the sealing hole 60 is etched.

  In the thirteenth step, as shown in FIG. 6C, the film resist 18 is pasted on the mask layer 36, a pattern for opening the third through hole 54 is formed by photolithography, and the surface silicon layer 13 is etched. The second through hole 52 is formed.

  In the fourteenth step, as shown in FIG. 6D, after removing the film resist 18, the second through hole 52 and the element adjustment layer 30 in the first sealing hole 60 are etched to form the second through hole. The element adjustment layer 30 is etched until the polysilicon film 41 in 52 is exposed.

  In the fifteenth step, as shown in FIG. 6E, the film resist 18 is pasted on the mask layer 36, a pattern for opening the second sealing hole 62 is formed by photolithography, and the first sealing hole 60 is formed. The inner element adjustment layer 30 is etched to expose the polysilicon film 41 in the first sealing hole 60.

  In the sixteenth step, as shown in FIG. 6F, the surface of the mask layer 36 on the silicon layer 11, the first through hole 51ac, the second through hole 52, the third through hole 54, the first through the CVD method. A silicon oxide film 32 is formed on the side walls in the first sealing hole 60 and the second sealing hole 62. Thereafter, the mask layer 36, element adjustment, excluding the side walls in the first through hole 51ac, the second through hole 52, the third through hole 54, the first sealing hole 60, and the second sealing hole 62 The layer 30, the wiring 46, and the silicon oxide film 32 on the surface of the polysilicon film 41 are removed by anisotropic dry etching such as reactive ion etching (RIE). Thereafter, in a pretreatment chamber such as a sputtering apparatus, the polysilicon film 41 exposed in the first sealing hole 60 is etched in a vacuum (reduced pressure) atmosphere to form the polysilicon film 41 on the first sealing hole 60. Create a through hole.

  In the seventeenth step, as shown in FIG. 6G, the internal space formed by the cavities 7 and 8 is set to the same pressure as the pretreatment chamber, the wiring electrode 56 is sputtered by continuous treatment, and the first sealing is performed. The internal space formed by the cavities 7 and 8 in which the element 20 is formed, which closes the hole 60, is sealed in a vacuum atmosphere (reduced pressure atmosphere).

  In the eighteenth step, as shown in FIG. 6H, the wiring electrode 58 is formed on the surface of the wiring electrode 56 by plating or the like. Thereafter, the surface of the SOI substrate 10 opposite to the surface to which the lid portion 5 is bonded is planarized by a polishing apparatus or the like, whereby the strength of the electrode pad 50 is improved and the MEMS element 1a having excellent reliability is completed. To do.

(Third embodiment)
[MEMS element]
Next, a MEMS element 1b according to a third embodiment of the present invention will be described with reference to FIGS. 7A and 7B.
7A is a schematic plan view of R1 in FIG. 1 showing the configuration of the MEMS element 1b according to the third embodiment, and FIG. 7B is a schematic cross-sectional view taken along line P3-P3 in FIG. 7A. In addition, it demonstrates centering around difference with embodiment mentioned above, the same code | symbol is attached | subjected to the same structure, The description is abbreviate | omitted about the same matter.

The MEMS element 1b according to the third embodiment has a first through hole 51ad and a second through hole compared to the first through hole 51 and the second through hole 52 of the MEMS element 1 according to the first embodiment. The shape and configuration of 52b are different.
As shown in FIG. 7A, the first through hole 51ad and the second through hole 52b of the MEMS element 1b of the present embodiment are disposed at positions overlapping the electrode pad 50 and the third through hole 54 in plan view. The opening widths W3 and W4 of the first through hole 51ad and the second through hole 52b are smaller than the opening width W5 of the third through hole 54. Also, as shown in FIG. 7B, the first through hole 51ad is disposed in the element adjustment layer 30, and the second through hole 52b is disposed in the surface silicon layer 13, and the first through hole The opening width W3 of 51ad is larger than the opening width W4 of the second through hole 52b.

  As described above, according to the MEMS element 1b according to the present embodiment, the opening widths W3 and W4 of the first through hole 51ad and the second through hole 52b are larger than the opening width W5 of the third through hole 54. Therefore, the area of the element adjustment layer 30 that supports the electrode pad 50 and the surface silicon layer 13 that constitutes the second through hole 52b can be increased, and the strength that supports the electrode pad 50 can be improved. The strength of 50 can be improved.

  In addition, since the first through hole 51ad formed by the element adjustment layer 30 and the second through hole 52b formed by the surface silicon layer 13 have a portion overlapping in plan view, While improving the support strength, electrical connection between the electrode pad 50 and the wiring electrodes 56 and 58 can be achieved, and the MEMS element 1b having excellent reliability can be obtained.

[Production method]
Next, the manufacturing process of the MEMS element 1b according to the third embodiment will be described with reference to FIGS. 8A to 8F.
8A to 8F are schematic cross-sectional views corresponding to the position of the P1-P1 line in FIG. 1 showing the manufacturing process of the MEMS element 1b according to the third embodiment. Note that a line indicating the background of the cross section is omitted. Note that the manufacturing process in the third embodiment is the same from the first process to the eleventh process (FIGS. 3A to 3K) of the manufacturing process in the first embodiment described above, and therefore the eleventh process (FIG. 3K). The subsequent steps will be described.

  In the eleventh step, as shown in FIG. 8A, the third through hole 54 and the second sealing hole 62 are formed by etching the silicon layer 11 of the SOI substrate 10 using the mask layer 36 as a mask.

  In the twelfth step, as shown in FIG. 8B, the BOX layer 12 of the SOI substrate 10 in the third through hole 54 and the second sealing hole 62 is etched, and then the exposed trench 51b and the first The element adjustment layer 30 in the sealing hole 60 is etched. By over-etching the element adjustment layer 30, the element adjustment layer 30 of the surface silicon layer 13 and the polysilicon film 41 located at the center of the second through hole 52b is etched, and the element adjustment layer 30 is formed at the center of the second through hole 52b. The located surface silicon layer 13 falls off, and the second through hole 52b and the first through hole 51ad are formed.

  In the thirteenth step, as shown in FIG. 8C, the surface of the mask layer 36 on the silicon layer 11 and the surface of the polysilicon film 41 in the first through hole 51ad and the first sealing hole 60 are formed by CVD. The silicon oxide film 32 is formed on the first through hole 51ad, the second through hole 52b, the third through hole 54, the side wall in the first sealing hole 60, and the second sealing hole 62. Film.

  As shown in FIG. 8D, the fourteenth step is performed in the first through hole 51ad, the second through hole 52b, the third through hole 54, the first sealing hole 60, and the second sealing hole 62. The silicon oxide film 32 on the surface of the mask layer 36 and the polysilicon film 41 excluding the side wall is removed by anisotropic dry etching such as reactive ion etching (RIE).

  In the fifteenth step, as shown in FIG. 8E, the polysilicon film 41 exposed to the first through hole 51ad and the first sealing hole 60 in a vacuum (decompressed) atmosphere in a pretreatment chamber such as a sputtering apparatus. Is etched to form a through hole in the polysilicon film 41 on the first through hole 51ad and the first sealing hole 60. Thereafter, the internal space constituted by the cavities 7 and 8 is set to a pressure equivalent to that of the pretreatment chamber, the wiring electrode 56 is sputtered by continuous treatment, and the first sealing hole 60 is closed, and the element 20 is formed. The internal space formed by the cavities 7 and 8 is sealed in a vacuum atmosphere (reduced pressure atmosphere). In addition, the wiring electrode 56 and the wiring 46 are electrically connected in the through hole of the polysilicon film 41 in the first through hole 51ad.

  In the sixteenth step, as shown in FIG. 8F, a wiring electrode 58 is formed on the surface of the wiring electrode 56 by plating or the like. Thereafter, the surface of the SOI substrate 10 opposite to the surface to which the lid portion 5 is bonded is planarized with a polishing apparatus or the like, thereby completing the MEMS element 1b with improved strength of the electrode pad 50 and excellent reliability. To do.

[Electronics]
Next, electronic devices to which the MEMS elements 1, 1a, 1b according to an embodiment of the present invention are applied will be described with reference to FIG. 9, FIG. 10, and FIG. Hereinafter, a configuration to which the MEMS element 1 is applied will be described as an example.

  FIG. 9 is a perspective view schematically illustrating a configuration of a mobile (or notebook) personal computer as an electronic apparatus including the MEMS element 1 according to the present embodiment. In this figure, a personal computer 1100 includes a main body 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display 1000. The display unit 1106 rotates with respect to the main body 1104 via a hinge structure. Supported as possible. Such a personal computer 1100 incorporates a MEMS element 1 that functions as a reference clock or the like.

  FIG. 10 is a perspective view schematically illustrating a configuration of a mobile phone (including a PHS (Personal Handyhone System) and a smartphone) as an electronic device including the MEMS element 1 according to an embodiment of the present invention. In this figure, a cellular phone 1200 is provided with a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and a display 1000 is disposed between the operation buttons 1202 and the earpiece 1204. Such a cellular phone 1200 incorporates a MEMS element 1 that functions as a reference clock or the like.

FIG. 11 is a perspective view schematically illustrating a configuration of a digital still camera as an electronic apparatus including the MEMS element 1 according to an embodiment of the present invention. In this figure, connection with an external device is also simply shown. The digital still camera 1300 generates an imaging signal (image signal) by photoelectrically converting an optical image of a subject using an imaging element such as a CCD (Charge Coupled Device).
A display 1000 is provided on the back of a case (body) 1302 in the digital still camera 1300, and the display 1000 is configured to display based on an imaging signal from the CCD. The display 1000 is a finder that displays an object as an electronic image. Function. 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 1000 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308. In the digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1330 is connected to the video signal output terminal 1312 and a personal computer 1340 is connected to the input / output terminal 1314 for data communication as necessary. Furthermore, the imaging signal stored in the memory 1308 is output to the television monitor 1330 or the personal computer 1340 by a predetermined operation. Such a digital still camera 1300 incorporates a MEMS element 1 that functions as a reference clock or the like.

  As described above, a high-performance electronic device can be provided by utilizing the MEMS element 1 having excellent reliability in the electronic device.

  The MEMS elements 1, 1a and 1b according to the embodiment of the present invention include a personal computer 1100 (mobile personal computer) in FIG. 9, a mobile phone 1200 in FIG. 10, and a digital still camera 1300 in FIG. , For example, inkjet type ejection device (for example, inkjet printer), laptop personal computer, TV, video camera, car navigation device, pager, electronic notebook (including communication function), electronic dictionary, calculator, electronic game device, work Station, video phone, TV monitor for crime prevention, electronic binoculars, POS (Point of Sale) terminal, medical equipment (for example, electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish school Detectors, various measuring instruments, instruments (eg cars It can be applied to electronic equipment such as aircraft, ship instruments, flight simulators, etc.

[Moving object]
Next, a moving body to which the MEMS elements 1, 1a, 1b according to one embodiment of the present invention are applied will be described with reference to FIG. Hereinafter, a configuration to which the MEMS element 1 is applied will be described as an example.
FIG. 12 is a perspective view schematically showing an automobile 1400 as an example of the moving object of the present invention.
The MEMS element 1 is mounted on the automobile 1400. MEMS element 1 is keyless entry, immobilizer, navigation system, air conditioner, antilock brake system (ABS), airbag, tire pressure monitoring system (TPMS), engine control, hybrid car and electric The present invention can be widely applied to an electronic control unit (ECU: Electronic Control Unit) 1410 such as an automobile battery monitor and a vehicle body attitude control system.

  As described above, by using the MEMS element 1 having excellent reliability for the moving body, it is possible to provide a higher-performance moving body.

  Although the MEMS elements 1, 1a, 1b, the electronic devices (1100, 1200, 1300), and the moving body (1400) according to the present invention have been described based on the illustrated embodiments, the present invention is not limited thereto. Instead, the configuration of each part can be replaced with any configuration having the same function. In addition, any other component may be added to the present invention. Moreover, you may combine each embodiment mentioned above suitably.

  In the above-described embodiment, the example has been described in which the element 20 is disposed so that the base portion 21 and the vibration portion 22 extend along the direction of one diagonal line of the rectangular SOI substrate 10. Not limited to. Another example of arrangement may be a configuration in which the element 20 is arranged so that the base 21 and the vibration part 22 extend along the outer edge of the rectangular SOI substrate 10.

  In the above description, the MEMS elements 1, 1a, and 1b including the element 20 as a functional element including the base portion 21 and the vibration portion 22 are illustrated and described as an example of the MEMS element, but the present invention is not limited thereto. Other MEMS elements having the above-described sealing structure include an acceleration sensor element having an acceleration detection function as a functional element, an angular velocity sensor element having an angular velocity detection function, and a pressure having a pressure detection function. It may be a sensor element, a weight sensor element having a weight detection function, or a MEMS element having a composite sensor in which these functional elements are combined. Further, the MEMS element may be a vibrator, an oscillator, a frequency filter, or the like provided with a vibration element as a functional element.

  DESCRIPTION OF SYMBOLS 1, 1a, 1b ... MEMS element, 5 ... Cover part, 7, 8 ... Cavity, 10 ... SOI substrate, 11 ... Silicon layer, 12 ... BOX layer, 13 ... Surface silicon layer, 13a ... Groove, 13b ... Trench, 13c: slit, 14, 16 ... resist, 18 ... film resist, 20 ... element, 21 ... base, 22 ... vibration part, 30 ... element adjustment layer, 32, 33, 34 ... silicon oxide film, 36 ... mask layer, 38 ... partition wall, 40 ... piezoelectric drive unit, 41 ... polysilicon film, 42 ... first electrode, 43 ... piezoelectric layer, 44 ... second electrode, 46 ... wiring, 50 ... electrode pad, 51 ... first penetration Hole 51b ... Trench 52 ... Second through hole 54 ... Third through hole 56, 58 ... Wiring electrode 60 ... First sealing hole 62 ... Second sealing hole 1000 ... Display 1100. Personal computer DESCRIPTION OF SYMBOLS 1102 ... Keyboard, 1104 ... Main part, 1106 ... Display unit, 1200 ... Mobile phone, 1202 ... Operation button, 1204 ... Earpiece, 1206 ... Mouthpiece, 1300 ... Digital still camera, 1302 ... Case, 1304 ... Light receiving unit DESCRIPTION OF SYMBOLS 1306 ... Shutter button 1308 ... Memory, 1312 ... Video signal output terminal, 1314 ... Input / output terminal, 1330 ... Television monitor, 1340 ... Personal computer, 1400 ... Car, 1410 ... Electronic control unit, W1, W2, W3, W4 , W5... Opening width.

Claims (8)

An element substrate having an element and an element electrode for driving the element;
A support substrate for supporting the element substrate,
An electrode pad disposed on the element substrate and connected to the element electrode;
An element adjustment layer is disposed between the element substrate and the electrode pad,
The element adjustment layer is provided with a first through hole at a position overlapping the electrode pad in plan view,
The element substrate is provided with a second through hole communicating with the first through hole at a position overlapping the electrode pad in plan view.
The support substrate is provided with a third through hole communicating with the second through hole at a position overlapping the electrode pad in plan view.
The opening width of the first through hole is smaller than the opening width of the second through hole,
A wiring element that is electrically connected to the electrode pad is disposed in the first through hole, the second through hole, and the third through hole.   2. The MEMS according to claim 1, wherein the element adjustment layer disposed at a position overlapping the second through hole in a plan view extends to the second through hole in a cross sectional view. element.   The MEMS element according to claim 2, wherein there are a plurality of the first through holes, and the first through holes are separated from each other by a partition wall.   The MEMS device according to claim 3, wherein three or more of the partition walls intersect at one point. An element substrate having an element and an element electrode for driving the element;
A support substrate for supporting the element substrate,
An electrode pad disposed on the element substrate and connected to the element electrode;
An element adjustment layer is disposed between the element substrate and the electrode pad,
The element adjustment layer is provided with a first through hole at a position overlapping the electrode pad in plan view,
The element substrate is provided with a second through hole communicating with the first through hole at a position overlapping the electrode pad in plan view.
The support substrate is provided with a third through hole communicating with the second through hole at a position overlapping the electrode pad in plan view.
The opening width of the first through hole and the second through hole is smaller than the opening width of the third through hole,
A wiring element that is electrically connected to the electrode pad is disposed in the first through hole, the second through hole, and the third through hole.   6. The MEMS element according to claim 5, wherein the element adjustment layer and the element substrate each include the first through hole and the second through hole having portions overlapping in plan view.   An electronic apparatus comprising the MEMS element according to any one of claims 1 to 6.   A moving body comprising the MEMS element according to claim 1.

Images