JP2019062418A - Electronic device and method of manufacturing electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic device having high airtightness and a method for manufacturing the electronic device. An electronic device 1 is accommodated in an accommodation space S composed of a first main surface 10a of an element substrate 10 and a lid portion 20 joined to the first main surface 10a. The electronic device 1 is a recess 17 having an opening on the side of the second main surface 10b opposite to the first main surface 10a of the element substrate 10, and the bottom 17a and the first main surface of the recess 17. It has a membrane portion 15 composed of 10a, and the membrane portion 15 has a sealing hole 14 penetrating the membrane portion 15 and is a first surface of the membrane portion 15 on the first main surface 10a side. The 15a and the sealing hole 14 are covered with a porous first sealing portion 30, and the second surface 15b (bottom 17a of the recess 17) and the second main surface 10b side of the membrane portion 15 and the sealing hole 14 are covered. The sealing portion surface 30a on the second main surface 10b side of the first sealing portion 30 is covered with the second sealing portion 40. [Selection diagram] Fig. 2

Description

  The present invention relates to an electronic device and a method of manufacturing the electronic device.

  In a semiconductor device or an electronic device formed using a semiconductor substrate, for example, an element such as a transistor, as a method of sealing a cavity around the element, Patent Document 1 discloses a semiconductor substrate on which an element and a filter having a mesh structure are formed. A cover film covering the element is provided while forming a cavity between the element and a thin film covering the filter from the back surface side of the semiconductor substrate through the via hole to the via hole reaching the filter from the back surface side of the semiconductor substrate A method of manufacturing a semiconductor device is disclosed in which the cavity around the element is hermetically sealed in a short time with good sealing.

JP, 2009-170588, A

  However, in the manufacturing method described in Patent Document 1, when forming a thin film covering a mesh structure filter through a via hole to seal a cavity around the element, the thin film for sealing is formed from the mesh portion of the filter There is a problem that the resin enters into the cavity and adheres to the surface of the element to deteriorate the characteristics.

  The present invention has been made to solve at least a part of the above-described problems, and can be realized as the following modes or application examples.

  Application Example 1 In the electronic device according to this application example, the element portion is accommodated in the accommodation space formed by the first main surface of the element substrate and the lid portion joined to the first main surface. An electronic device, wherein the recess has an opening on the side of the second main surface opposite to the first main surface of the element substrate, the bottom of the recess and the first main surface A membrane portion, and the membrane portion includes a sealing hole penetrating the membrane portion, and a first surface on the first main surface side of the membrane portion and the sealing hole A second surface (bottom of the recess) which is covered with the porous first sealing portion and which is the second main surface side of the membrane portion, and the first surface of the first sealing portion The sealing portion surface on the main surface side of 2 is characterized by being covered with a second sealing portion.

  According to this application example, the storage space formed by the element substrate and the lid is covered with the first sealing portion having a porous property from the side of the storage space in the sealing hole provided in the element substrate. By sealing the sealing portion surface of the sealing portion on the sealing hole side with the second sealing portion of metal, airtight sealing can be performed. In addition, since the first sealing portion for closing the sealing hole from the housing space side is porous, particles of the second sealing portion may pass through the inside of the first sealing portion and reach the housing space. Can not. That is, the first sealing portion is constituted by a large number of pores connected in a complicated manner. Therefore, during film formation of the second sealing portion, the particles of the second sealing portion adhere to the large number of pores constituting the first sealing portion, and therefore the particles do not enter the accommodation space. Therefore, when the housing space is hermetically sealed, the particles of the second sealing portion adhere to the element portion, and the characteristics of the element portion are prevented from being degraded, and an electronic device having stable characteristics is obtained. You can get it.

  Application Example 2 In the electronic device described in the application example, the first sealing portion is preferably a sputtered film of aluminum oxide.

  According to this application example, since the first sealing portion is aluminum oxide, it is possible to easily form a porous sputtered film of aluminum oxide by sputtering aluminum oxide.

  Application Example 3 In the electronic device according to the application example, the second sealing portion is preferably a metal film or a metal oxide film.

  According to this application example, since the second sealing portion is a metal film or a metal oxide film, a dense film can be easily formed, and the accommodation space can be maintained with high airtightness.

  Application Example 4 In the electronic device described in the application example, it is preferable that the metal film is extended from the conductive film provided on the second main surface.

  According to this application example, it is possible to form the second sealing portion for hermetically sealing the accommodation space simultaneously with the formation of the conductive film disposed on the second main surface, and to obtain high productivity. it can.

  Application Example 5 In the method of manufacturing an electronic device according to this application example, there is provided a substrate preparing step of preparing an SOI substrate in which an element portion is formed, and a first of the SOI substrate on the side where the element portion is formed. A first sealing portion forming step of forming a porous first sealing portion on the main surface, and a lid portion forming an accommodation space of the element portion on the first main surface of the SOI substrate Opening in the second main surface side opposite to the first main surface of the SOI substrate, in a forming process of the lid portion bonding step and the first sealing portion of the SOI substrate in plan view A recess forming step of forming a recess forming a membrane part by the SOI substrate, and removing a part of a bottom of the recess from a second main surface side opposite to the first main surface of the SOI substrate; A sealing hole forming step of forming a sealing hole in the membrane portion; And environmental, including a sealing step of hermetically sealing the sealing hole in the second sealing portion of the metal, characterized in that.

  According to this application example, the porous first sealing portion is formed on the SOI substrate in which the element portion is formed, and after the lid portion is joined, sealing is performed at a position overlapping the first sealing portion of the SOI substrate. By forming the hole and covering the sealing hole with the second sealing portion, the housing space including the SOI substrate and the lid portion can be hermetically sealed. In addition, since the first sealing portion is porous, when the sealing hole is hermetically sealed with the second sealing portion of metal, the second sealing portion of metal is the first sealing portion. It can not reach the accommodation space through the inside of the That is, the first sealing portion is constituted by a large number of pores connected in a complicated manner. Therefore, during film formation of the second sealing portion, the particles of the second sealing portion adhere to the large number of pores constituting the first sealing portion, and therefore the particles do not enter the accommodation space. Therefore, when the housing space is hermetically sealed, the particles of the second sealing portion adhere to the element portion, and the characteristics of the element portion are prevented from being degraded, and an electronic device having stable characteristics is obtained. It can be manufactured.

  Application Example 6 In the method of manufacturing an electronic device according to the application example, the sealing step preferably includes a conductive film forming step of forming a conductive film on the second main surface side.

  According to this application example, it is possible to form the second sealing portion for hermetically sealing the accommodation space simultaneously with the formation of the conductive film formed on the second main surface, and to obtain high productivity. .

The planar external view which abbreviate | omitted the cover part of the electronic device which concerns on 1st Embodiment. Sectional drawing which shows the cross section of the AA in FIG. The elements on larger scale of the B section in FIG. FIG. 7 is a flowchart showing the method of manufacturing the electronic device according to the first embodiment. FIG. 7 is a cross-sectional view showing the manufacturing process of the electronic device according to the first embodiment. FIG. 7 is a cross-sectional view showing the manufacturing process of the electronic device according to the first embodiment. FIG. 7 is a cross-sectional view showing the manufacturing process of the electronic device according to the first embodiment. FIG. 7 is a cross-sectional view showing the manufacturing process of the electronic device according to the first embodiment. FIG. 7 is a cross-sectional view showing the manufacturing process of the electronic device according to the first embodiment. FIG. 7 is a cross-sectional view showing the manufacturing process of the electronic device according to the first embodiment. Sectional drawing which shows the structure of the electronic device which concerns on 2nd Embodiment. FIG. 7 is a flowchart showing the method of manufacturing the electronic device according to the second embodiment. Sectional drawing which shows the structure of the electronic device which concerns on 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail based on the drawings. In each of the drawings shown below, in order to make each component have a size that can be recognized in the drawings, the dimensions and ratios of each component may be appropriately different from the actual components and described. is there.

First Embodiment
[Structure of Electronic Device]
First, the electronic device 1 according to the first embodiment will be described with reference to FIGS. 1, 2 and 3.
FIG. 1 is a plan external view of the electronic device 1 according to the first embodiment with the lid 20 omitted, and FIG. 2 is a cross-sectional view taken along the line A-A in FIG. These are the elements on larger scale of the B section in FIG. Note that, in FIGS. 1 to 3 and FIGS. 5 to 11 and FIG. 13 described below, an X axis, a Y axis, and a Z axis are illustrated as three axes orthogonal to each other.

  As shown in FIGS. 2 and 3, the electronic device 1 according to the first embodiment is a so-called SOI (Silicon on Insulator) in which a silicon oxide layer is inserted between a silicon substrate layer of single crystal silicon and a silicon layer. A device substrate 10 formed using a substrate or a semiconductor substrate such as a silicon substrate mainly made of single crystal silicon as a substrate material M (not shown) and a lid joined to the first major surface 10 a of the device substrate 10 And a unit 20.

  The lid 20 has a lid cavity 21 on the side opposite to the first major surface 10 a of the element substrate 10, and the first major surface 10 a of the element substrate 10 and the bonding surface 20 a of the lid 20 are joined As a result, a part of the accommodation space S is configured. The material of the lid 20 is not particularly limited, but glass is preferably used.

The element substrate 10 includes an element forming layer 11 in which a silicon oxide (SiO ₂ ) layer of an SOI substrate and a silicon (Si) layer are stacked, and a base 12 of the silicon (Si) layer. The element substrate 10 is formed with a so-called MEMS (Micro Electro Mechanical System), for example, an element portion 13 which is a vibrator, and a base cavity 16 is formed in the base 12 of the formation region of the element portion 13. The base cavity 16 and the lid cavity 21 of the lid 20 constitute an accommodation space S for accommodating the element unit 13.

  A porous first sealing portion 30 is provided on the first major surface 10 a of the outer portion of the base cavity 16 of the element substrate 10. Further, in a region overlapping the first sealing portion 30 of the element substrate 10 in a plan view from the direction in which the element substrate 10 and the lid portion 20 overlap (viewed from the Z-axis direction), the first main surface 10 a A recess 17 is provided on the side of the second main surface 10b opposite to that of the first embodiment, and has a membrane portion 15 constituted by the bottom 17a of the recess 17 and the first main surface 10a. That is, the membrane portion 15 is formed in the element forming layer 11, and the sealing hole 14 penetrating the membrane portion 15 is provided at the central portion.

  The first surface 15 a on the side of the first major surface 10 a of the membrane portion 15 and the sealing hole 14 are covered with the porous first sealing portion 30, and the second main surface of the membrane portion 15 is The second surface 15 b (bottom 17 a of the recess 17) which is the surface 10 b side and the sealing portion surface 30 a of the first sealing portion 30 on the second major surface 10 b side are metal second sealing portions 40. It is covered with

  In the first main surface 10a, the planar shapes of the first sealing portion 30, the sealing hole 14 and the recess 17 are rectangular as shown in FIG. 1 in plan view (as viewed in the Z-axis direction) is there. In the electronic device 1 according to the present embodiment, the planar shape of the first sealing portion 30, the sealing hole 14, and the concave portion 17 is exemplified as a rectangular shape, but is not limited thereto. It may be circular or oval. Moreover, although the form in which the 1st sealing part 30, the sealing hole 14, and the recessed part 17 which each overlaps is formed in one place is illustrated, it is not limited to this, You may be formed in multiple numbers.

  The material that constitutes the first sealing portion 30 is preferably aluminum oxide, and the first sealing portion 30 is formed by sputtering aluminum oxide. Therefore, a sputtered film of porous aluminum oxide having a large number of pores can be easily formed. In addition, since the 1st sealing part 30 is comprised by many pores, the pressure of the accommodation space S, the exterior of accommodation space S, and pressure can be made the same, for example, the pressure reduction atmosphere of the electronic device 1 is carried out. By forming the second sealing unit 40 in the film, the accommodation space S can be hermetically sealed in a reduced pressure atmosphere. In addition, the first sealing portion 30 is formed such that the pores leading to the housing space S are connected in a complicated manner. Therefore, during deposition of the second sealing unit 40, the particles of the second sealing unit adhere to the large number of pores constituting the first sealing unit 30, so that the second sealing unit Particles can be prevented from entering the storage space.

The material constituting the second sealing portion 40 is preferably a metal film or a metal oxide film. The metal film is, for example, a metal such as Au, Ag, Cu, Al, or Pt, and the metal oxide film is, for example, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), In ₃ O ₃ , SnO ₂ , The oxide-based conductive material such as Sb-containing SnO ₂ and Al-containing ZnO is preferably used. Since the second sealing portion 40 is a metal film or a metal oxide film, a dense film can be easily formed. Therefore, the dense film of the second sealing portion 40 enters the pores scattered in the sealing portion surface 30 a of the first sealing portion 30 in the sealing hole 14, and the fineness of the first sealing portion 30 The accommodation space S can be airtightly sealed by closing the hole and then laminating the second sealing portion 40 on the sealing portion surface 30 a to close the sealing hole 14.

  As described above, in the electronic device 1 according to the first embodiment, the accommodation space S formed by the element substrate 10 and the lid 20 is compared with the sealing hole 14 provided in the element substrate 10 from the accommodation space S side. Airtight sealing is performed by covering with the porous first sealing portion 30 and covering the sealing portion surface 30 a of the first sealing portion 30 on the sealing hole 14 side with the second sealing portion 40 of metal. can do. In addition, since the first sealing portion 30 for closing the sealing hole 14 from the accommodation space S side is porous, the second metal sealing portion 40 passes through the inside of the first sealing portion 30 and is accommodated. The space S can not be reached. That is, the first sealing portion 30 is constituted by a large number of pores connected in a complicated manner. Therefore, during deposition of the second sealing unit 40, the particles of the second sealing unit adhere to a large number of pores constituting the first sealing unit 30, and hence the particles may enter the accommodation space S. Absent. Therefore, when the accommodation space S is hermetically sealed, the particles of the second sealing unit 40 can be attached to the element unit 13 to reduce the deterioration of the characteristics of the element unit 13, and stable characteristics can be obtained. The electronic device 1 can be obtained.

  In addition, since the first sealing portion 30 is aluminum oxide, it is possible to easily form a porous sputtered film of aluminum oxide by sputtering aluminum oxide. In addition, a vacuum film formation method other than sputtering may be appropriately used, and a material to be used may be suitably selected.

  In addition, since the second sealing portion 40 is a metal film or a metal oxide film, a dense film can be easily formed, and the accommodation space S can be maintained with high airtightness.

[Method of manufacturing electronic device]
Next, a method of manufacturing the electronic device 1 according to the first embodiment will be described with reference to FIGS.
FIG. 4 is a flowchart showing the method of manufacturing the electronic device 1 according to the first embodiment, and FIGS. 5 to 10 are cross-sectional views showing the manufacturing process of the electronic device 1 according to the first embodiment.

[Substrate preparation process]
First, in the substrate preparation step (S1), the SOI substrate is used as a substrate material M (not shown), and the element substrate 10 on which the element portion 13 is formed as shown in FIG. 5 is prepared. In the element substrate 10, the element portion 13 is formed in the element forming layer 11, and a base cavity 16 is formed in the base 12 of the formation area of the element portion 13.

[First Sealed Part Forming Step]
A first sealing portion forming step (S2) is performed on the element substrate 10 prepared in the substrate preparing step (S1). The first sealing portion forming step (S2) is, as shown in FIG. 6, a porous first porous member having a planar shape so as to surround a sealing hole formed in a sealing hole forming step (S5) described later. The sealing portion 30 is formed. The first sealing portion 30 is preferably made of porous aluminum oxide or the like. The first sealing portion 30 is formed by depositing aluminum oxide on the first major surface 10a by a sputtering method, and then forming the first sealing portion 30 into a predetermined shape using a resist mask patterned and formed by a photolithography method or the like. Ru.

[Lid part joining process]
In the lid bonding step (S3), the bonding surface 20a of the lid 20 is disposed on the first major surface 10a of the element substrate 10, and the lid 20 is bonded to the first major surface 10a of the element substrate 10. Although the case where the cover part made of glass is used in this example is illustrated in this example, it is not limited to this, For example, ceramics, a metal etc. may be sufficient.

  As shown in FIG. 7, the lid portion 20 has a lid portion cavity 21 on one side, and the lid portion 20 is disposed so that the lid portion cavity 21 faces the element substrate 10, and bonding is performed to the element substrate 10. As a result, the cover space 21 and the base cavity 16 of the base 12 form an accommodation space S for accommodating the element unit 13.

  Bonding of the lid 20 and the element substrate 10 is performed mainly by using borosilicate glass for the lid 20 and the bonding surface 20 a of the lid 20 and the first major surface 10 a of the element substrate 10, and mainly using silicon. A method of anodically bonding the element substrate 10 as a component, or fusion bonding through a low melting point glass powder between the bonding surface 20a of the lid 20 and the first major surface 10a of the element substrate 10 And the like are preferably used.

[Recess forming step]
In the recess forming step (S4), as shown in FIG. 8, the first sealing portion 30 of the element substrate 10 in a plan view (as viewed from the Z-axis direction) from the direction in which the element substrate 10 and the lid 20 overlap. The silicon forming the base 12 is removed by etching to the element forming layer 11 in the formation region of the element substrate 10, and the element substrate 10 is opened on the side of the second main surface 10b opposite to the first main surface 10a. A concave portion 17 constituting the membrane portion 15 is formed by the substrate. By forming the concave portion 17, the membrane portion 15 is formed of the element forming layer 11, and the second surface 15 b of the membrane portion 15 appears at the bottom portion 17 a of the concave portion 17.

[Sealing hole forming process]
In the sealing hole forming step (S5), as shown in FIG. 9, the element forming layer 11 in the region where the first sealing portion 30 and the concave portion 17 overlap in plan view (viewed from the Z-axis direction) The silicon oxide and silicon to be removed are etched away to the first sealing portion 30 to form a sealing hole 14. That is, the sealing hole 14 is formed in the membrane portion 15 by etching and removing a part of the second surface 15 b of the membrane portion 15 (the bottom 17 a of the recess 17).

[Sealing process]
Next, a sealing step (S6) of maintaining the space environment of the accommodation space S at a predetermined environment is performed. In the sealing step (S6), the housing space S is provided via the porous first sealing portion 30 and the sealing hole 14 disposed between the housing space S and the outside of the housing space S. The air of the internal space of, for example, air is evacuated, and the storage space S is maintained in a reduced pressure state.

  Thereafter, as shown in FIG. 10, in the sealing step (S6), the second main surface 10b side is covered so as to cover the sealing hole 14 while maintaining the reduced pressure atmosphere which is the desired space environment of the accommodation space S. The second sealing portion 40 is formed, the housing space S is hermetically sealed, and the electronic device 1 according to the first embodiment is obtained. Specifically, the inside of the housing space S is in a reduced pressure state, and the second surface 15 b on the side of the second main surface 10 b of the membrane unit 15 and the first seal formed on the membrane unit 15 By covering the sealing portion surface 30 a of the portion 30 with the second sealing portion 40 formed by the sputtering method, the housing space S is hermetically sealed.

Here, the second sealing portion 40 is preferably a metal film or a metal oxide film. The metal film is, for example, a metal such as Au, Ag, Cu, Al, or Pt, and the metal oxide film is, for example, ITO (Indium Tin Oxide), IZO (Indium Zinc Oxide), In ₃ O ₃ , SnO ₂ , The oxide-based conductive material such as Sb-containing SnO ₂ and Al-containing ZnO is preferably used.

  By the above steps, the electronic device 1 having high airtightness can be manufactured.

  As described above, in the electronic device 1 according to the first embodiment, the porous first sealing unit 30 is formed on the element substrate 10 (SOI substrate) on which the element unit 13 is formed, and the lid 20 is joined. Thereafter, the sealing hole 14 is formed at a position overlapping the first sealing portion 30 of the element substrate 10, and the sealing hole 14 is covered with the second sealing portion 40, whereby the element substrate 10 and the lid portion 20 are formed. The housing space S in which the element unit 13 is housed can be hermetically sealed. Since the first sealing portion 30 is porous, when the sealing hole 14 is hermetically sealed by the second sealing portion 40 of metal, the second sealing portion 40 of metal is the first It can not reach the accommodation space S through the inside of the sealing portion 30 of the That is, since the first sealing portion 30 is constituted by a large number of pores, it is difficult to form the pores linearly communicating with the accommodation space S. Therefore, since the metal second sealing unit 40 adheres to a large number of pores constituting the first sealing unit 30 during film formation, it does not enter the housing space S. Therefore, when the storage space S is hermetically sealed, the second sealing portion 40 may be attached to the element portion 13 to reduce deterioration of the characteristics of the element portion 13, and electrons having stable characteristics. Device 1 can be manufactured.

Second Embodiment
[Structure of Electronic Device]
Next, an electronic device 1a according to a second embodiment will be described with reference to FIG.
FIG. 11 is a cross-sectional view showing the structure of the electronic device 1a according to the second embodiment. In the electronic device 1a according to the second embodiment, the form of the second sealing portion 40 provided in the electronic device 1 according to the first embodiment is different, and the other components are the same. Therefore, in the description of the electronic device 1a according to the second embodiment, the same components as those of the electronic device 1 according to the first embodiment are given the same reference numerals, and the description will be omitted.

In the electronic device 1a according to the second embodiment, as shown in FIG. 11, a second sealing portion 40a for sealing the sealing hole 14 provided in the membrane portion 15 is formed. The second sealing portion 40 a is formed by extending the conductive film 50 formed on the second main surface 10 b side of the element substrate 10 to the recess 17 of the base 12. That is, the second sealing portion 40 a and the conductive film 50 are electrically connected, and can be made of the same material.
The conductive film 50 formed on the second main surface 10b side is for shielding noise from the mounting substrate when the second main surface 10b of the element substrate 10 is mounted facing the mounting substrate. Thus, the influence of external noise on the element unit 13 accommodated in the accommodation space S can be reduced.

  The material forming the conductive film 50 is preferably a metal film, and for example, a metal such as Au, Ag, Cu, Al, or Pt is preferably formed by sputtering.

  As described above, in the electronic device 1a according to the second embodiment, the second sealing portion 40a for sealing the sealing hole 14 in an airtight manner is formed to extend from the conductive film 50. Therefore, it is possible to form the second sealing portion 40a for hermetically sealing the storage space S simultaneously with the formation of the conductive film 50 disposed on the second main surface 10b, and to obtain high productivity. .

[Method of manufacturing electronic device]
Next, a method of manufacturing the electronic device 1a according to the second embodiment will be described with reference to FIG.
FIG. 12 is a flowchart showing the method of manufacturing the electronic device 1a according to the second embodiment. In addition, the manufacturing method of the electronic device 1a which concerns on 2nd Embodiment differs in the sealing process (S6) in the manufacturing method of the electronic device 1 which concerns on 1st Embodiment. Therefore, the description of the substrate preparation step (S1) to the sealing hole forming step (S5), which are the same manufacturing method as in the first embodiment, is omitted.

[Sealing process]
The sealing step (S60) in the method of manufacturing the electronic device 1a according to the second embodiment includes a conductive film forming step (S61) as shown in FIG.

[Conductive film forming process]
In the conductive film forming step (S 61), the conductive film 50, for example, a metal such as Au, Ag, Cu, Al, or Pt is sputtered from the side of the second main surface 10 b of the element substrate 10. The sealing hole 14 provided in the membrane portion 15 is air-laid by being laminated on the principal surface 10b of the second embodiment, the second surface 15b of the membrane portion 15, and the sealing portion surface 30a of the first sealing portion 30. A second sealing portion 40a that seals tightly can be formed.

  As described above, in the method of manufacturing the electronic device 1a according to the second embodiment, in the method of manufacturing the sealing step (S60), the conductive film forming step (S61) of forming the conductive film 50 When the conductive film 50 is formed on the main surface 10b of 2, the second sealing portion 40a that covers the sealing hole 14 provided in the membrane portion 15 can be simultaneously formed. Therefore, the electronic device 1a having high airtightness can be manufactured with high productivity.

Third Embodiment
[Structure of Electronic Device]
Next, an electronic device 1b according to a third embodiment will be described with reference to FIG.
FIG. 13 is a cross-sectional view showing the structure of the electronic device 1b according to the third embodiment. The electronic device 1b according to the third embodiment differs in the form of the recess 17 provided in the electronic device 1 according to the first embodiment, and the other components are the same. Accordingly, in the description of the electronic device 1b according to the third embodiment, the same components as those of the electronic device 1 according to the first embodiment are denoted by the same reference numerals, and the description will be omitted.

  In the electronic device 1b according to the third embodiment, as shown in FIG. 13, the recessed portion 17b provided in the element substrate 10 has a tapered portion which spreads from the first main surface 10a side to the second main surface 10b. Have. In addition, in this embodiment, although the taper part is provided in the recessed part 17b, you may provide from the middle of the recessed part 17b. In addition, the sealing hole 14 may be provided.

  As described above, in the electronic device 1b according to the third embodiment, the recess 17b includes the tapered portion that spreads toward the second major surface 10b, so the second sealing is performed from the second major surface 10b side. When forming the stopper portion 40 and sealing the sealing hole 14 provided in the membrane portion 15 airtight, the second sealing portion 40 can easily reach the sealing hole 14 and has high airtightness. The electronic device 1b can be obtained.

  1, 1a, 1b: electronic device, 10: element substrate, 10a: first main surface, 10b: second main surface, 11: element forming layer, 12: base, 13: element portion, 14: sealing hole , 15: membrane part, 15a: first surface, 15b: second surface, 16: base cavity, 17, 17b: recess, 17a: bottom, 20: lid, 20a: bonding surface, 21: lid Cavity, 30: first sealing portion, 30a: sealing portion surface, 40, 40a: second sealing portion, 50: conductive film, S: accommodation space.

Claims (6)

An electronic device in which an element portion is accommodated in an accommodation space formed by a first main surface of an element substrate and a lid joined to the first main surface,
It has a recess provided with an opening on the side of the second main surface opposite to the first main surface of the element substrate, and a membrane portion constituted by the bottom of the recess and the first main surface. ,
The membrane portion includes a sealing hole penetrating the membrane portion,
The first surface on the side of the first main surface of the membrane portion and the sealing hole are covered with a porous first sealing portion,
The second surface (bottom of the recess) on the second main surface side of the membrane portion and the sealing portion surface on the second main surface side of the first sealing portion are the second sealing Covered with stop,
An electronic device characterized by   The electronic device according to claim 1, wherein the first sealing portion is a sputtered film of aluminum oxide.   The electronic device according to claim 1, wherein the second sealing portion is a metal film or a metal oxide film.   The electronic device according to claim 3, wherein the metal film is extended from a conductive film disposed on the second main surface. A substrate preparation step of preparing an SOI substrate on which an element portion is formed;
A first sealing portion forming step of forming a porous first sealing portion on a first main surface of the SOI substrate on which the element portion is formed;
A lid bonding step of bonding a lid forming the housing space of the element unit to the first main surface of the SOI substrate;
In the formation region of the first sealing portion of the SOI substrate in plan view, the membrane portion is opened by the side of the second main surface opposite to the first main surface of the SOI substrate, A recess forming step of forming a recess to be configured;
A sealing hole forming step of removing a part of the bottom of the recess from the side of the second main surface opposite to the first main surface of the SOI substrate to form a sealing hole in the membrane portion;
And a sealing step of hermetically sealing the sealing hole with a second sealing portion of metal with the housing space as a predetermined space environment.
Method of manufacturing an electronic device characterized in that.   6. The method of manufacturing an electronic device according to claim 5, wherein the sealing step includes a conductive film forming step of forming a conductive film on the second main surface side.

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