JP2010098281A - Mems sensor, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an MEMS sensor, in particular, suppressing oxidation of the bonding surface of an Al layer, and appropriately subjected to eutectic bonding or diffusion bonding, in relation to a bonding structure having the Al layer between a support conduction part (anchor part) or the like and a wiring board. <P>SOLUTION: A first connection metal layer 41 is formed on a surface 12a of a support conduction part 12. The first connection metal layer 41 is formed with a laminate structure of the Al layer 51 and an oxidation prevention layer 52 formed on a surface 51a thereof. A second connection metal layer 31 is formed on a surface of the wiring board 2. The second connection metal layer 31 and the oxidation prevention layer 52 are formed of, for instance, Ge. The first connection metal layer 41 and the second connection metal layer 31 are subjected to eutectic bonding or diffusion bonding. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a MEMS sensor formed by finely processing a silicon substrate and a manufacturing method thereof.

  In a MEMS (Micro-Electro-Mechanical Systems) sensor, a movable electrode portion and a fixed electrode portion are formed by finely processing an SOI layer constituting an SOI (Silicon on Insulator) substrate. This fine sensor is used as an acceleration sensor, a pressure sensor, a vibration gyro, a micro relay, or the like depending on the operation of the movable electrode portion.

  FIG. 14 is a partial cross-sectional view of a conventional MEMS sensor, and FIG. 15 is an enlarged cross-sectional view showing a state before bonding between a support conduction portion (anchor portion) and a wiring board shown in FIG.

  The MEMS sensor illustrated in FIG. 14 includes an SOI substrate including a support substrate 200, an oxide insulating layer 203, and an SOI layer 210, and a wiring substrate 211 provided to face the SOI substrate.

  The movable region 201 composed of the movable electrode portion and the fixed electrode portion, and the support conduction portions 202 of the movable electrode portion and the fixed electrode portion are formed by finely processing the SOI layer 210.

  As shown in FIGS. 14 and 15, a first connection metal layer 212 is provided on the surface 202 a of the support conducting portion 202.

  The wiring substrate 211 includes a silicon substrate 204, an insulating layer 205, a lead layer 206, and the like, and a second connection metal layer 213 is formed on the surface facing the support conductive portion 202. The second connection metal layer 213 is electrically connected to the lead layer 206. Then, the first connection metal layer 212 and the second connection metal layer 213 are pressurized while being heated, so that the first connection metal layer 212 and the second connection metal layer 213 are eutectic bonded.

JP 2005-236159 A

  For example, the first connection metal layer 212 is made of Al, and the second connection metal layer 213 is made of Ge. Thereby, the 1st connection metal layer 212 and the 2nd connection metal layer 213 can be eutectic-bonded.

  However, a natural oxide layer 214 is formed on the bonding surface 212a of the first connection metal layer 212 made of Al as shown in FIG.

  Therefore, conventionally, in order to appropriately eutectic-bond the first connection metal layer 212 and the second connection metal layer 213, it is necessary to remove the natural oxide layer 214 by etching before the bonding step. became.

  In particular, even if the natural oxide layer 214 is removed, a natural oxide layer is formed on the bonding surface 212a of the first connection metal layer 212 after a while. It was necessary to migrate to.

  Further, the thickness of the first connection metal layer 212 made of Al must be formed to a certain extent in consideration of the removal amount of the natural oxide layer 214, and the removal amount of the natural oxide layer 214 is likely to vary. As a result, variations in the thickness dimension of the MEMS sensor, variations in bonding strength, and the like are likely to occur.

  Further, in the conventional structure, since the natural oxide layer remains on the surface of the Al layer, it is difficult to appropriately perform eutectic bonding or diffusion bonding, or uneven bonding easily, and it is difficult to obtain strong bonding strength.

  Therefore, the present invention solves the above-described conventional problems, and relates to a bonding structure including an Al layer between a support conductive portion (anchor portion) and a wiring board, and in particular, can suppress oxidation of the bonding surface of the Al layer, An object of the present invention is to provide a MEMS sensor capable of appropriately eutectic bonding or diffusion bonding and a method for manufacturing the same.

The MEMS sensor according to the present invention includes a first substrate that is laminated in the order of a support substrate, an intermediate layer, and a functional layer, a movable electrode portion and a fixed electrode portion that are formed on the functional layer so as to face the functional layer. And a wiring board provided with a conduction path to
The functional layer is fixedly supported on the intermediate layer, and a bonding layer bonded to the wiring board is formed,
A first connection metal layer is formed on the surface of the bonding layer, a second connection metal layer is formed on the surface of the wiring board, and the first connection metal layer and the second connection metal layer are shared. Crystal bonding or diffusion bonding,
Of the first connection metal layer and the second connection metal layer, at least one of the connection metal layers is an antioxidant layer formed on the bonding surface of the Al layer and the other connection metal layer of the Al layer. It is characterized by being formed.

  Thereby, oxidation of the bonding surface of the Al layer can be prevented. Therefore, the joint strength between the first connection metal layer and the second connection metal layer can be improved, and the mechanical strength of the MEMS sensor can be improved.

  In the present invention, it is preferable that the antioxidant layer is formed with a film thickness that allows the Al layer and the second connection metal layer to perform eutectic bonding or diffusion bonding. Specifically, the thickness of the antioxidant layer is preferably formed within a range of 50 to 500 mm. By forming the antioxidant layer thin in this way, it is possible to prevent the eutectic bonding or diffusion bonding between the Al layer and the second connection metal layer from being inhibited while exhibiting the antioxidant function for the Al layer. The first connection metal layer and the second connection metal layer can be firmly joined.

  In the present invention, the antioxidant layer is preferably formed of a material that can be eutectic with Al or diffused into the Al layer. Thereby, eutectic bonding or diffusion bonding between the first connection metal layer and the second connection metal layer can be effectively promoted.

  Furthermore, in the present invention, in the above, it is preferable that the second connection metal layer has a portion formed of the same material as that of the antioxidant layer at least on the bonding surface side with the antioxidant layer. This can effectively increase the bonding strength.

The MEMS sensor according to the present invention includes a first substrate laminated in the order of a support substrate, an intermediate layer, and a functional layer, and a movable electrode portion and the fixed electrode that are formed on the functional layer so as to face the functional layer. A wiring board having a conduction path to the part,
The functional layer is fixedly supported on the intermediate layer, and a bonding layer bonded to the wiring board is formed,
A first connection metal layer is formed on the surface of the bonding layer, a second connection metal layer is formed on the surface of the wiring board, and the first connection metal layer and the second connection metal layer are shared. Crystal bonding or diffusion bonding,
Of the first connection metal layer and the second connection metal layer, one connection metal layer is an Al layer and a coating layer formed on the surface of the Al layer facing the other connection metal layer, Formed with
The covering layer is formed of the same material as that of the other connecting metal layer and is thinner than the other connecting metal layer.

  As a result, the eutectic or diffusion generated between the Al layer and the coating layer is caused by the reaction start trigger (the active point of the reaction start) of the eutectic bonding or diffusion bonding between the first connecting metal layer and the second connecting metal layer. Therefore, the bonding strength between the first connection metal layer and the second connection metal layer can be improved, and the mechanical strength of the MEMS sensor can be improved.

  In the present invention, it is preferable that a recess that is recessed from the surface of the Al layer in a direction away from the other connection metal layer is formed, and the coating layer is formed in the recess.

  Or in this invention, the convex part which protrudes toward the said other connection metal layer from the surface of the said Al layer is formed, and the said coating layer is formed in the said surface located in the bottom of the said convex part Is preferred.

  As described above, the bonding strength between the first connection metal layer and the second connection metal layer can be more effectively improved, and the mechanical strength of the MEMS sensor can be further improved.

  In the present invention, for example, the bonding layer is a support conduction portion connected to each of the movable electrode portion and the fixed electrode portion. Alternatively, the bonding layer is a frame layer that is formed separately from the movable electrode portion and the fixed electrode portion, and surrounds the movable region of the movable electrode portion, and the first connection metal layer and the second connection layer The connecting metal layer is eutectic bonded or diffusion bonded to form a metal sealing layer surrounding the outer periphery of the movable region.

  In the present invention, the wiring board is electrically connected to a silicon substrate, an insulating layer on the surface of the silicon substrate, and each of the movable electrode portion and the fixed electrode portion embedded in the insulating layer. It is preferable that the first connecting metal layer is formed. As a result, the wiring board can be formed with a simple structure, and the MEMS sensor can be thinned.

Moreover, the manufacturing method of the MEMS sensor in the present invention is as follows.
A first substrate that is laminated in the order of a support substrate, an intermediate layer, and a functional layer, and a wiring that has a conduction path between the movable electrode portion and the fixed electrode portion that are formed in the functional layer so as to face the functional layer A substrate,
Forming a bonding layer fixedly supported by the intermediate layer on the functional layer;
Forming a first connection metal layer on the surface of the bonding layer, forming a second connection metal layer on the surface of the wiring board;
At this time, at least one of the first connection metal layer and the second connection metal layer is formed to have an Al layer, and further, the other connection metal layer of the Al layer Forming an antioxidant layer on the bonding surface of
Eutectic bonding or diffusion bonding the first connection metal layer and the second connection metal layer;
It is characterized by having.

  According to the above MEMS sensor manufacturing method, oxidation of the bonding surface of the Al layer can be effectively suppressed. Therefore, in the present invention, the first connection metal layer and the second connection metal layer can be eutectic-bonded or diffusion-bonded easily and appropriately as compared with the prior art.

  In the present invention, it is preferable that the antioxidant layer is formed with a film thickness that enables the Al layer and the second connection metal layer to perform eutectic bonding or diffusion bonding. Specifically, it is preferable to form the thickness of the antioxidant layer within a range of 50 to 500 mm. By forming the antioxidant layer thin in this way, it is possible to prevent the eutectic bonding or diffusion bonding between the Al layer and the second connection metal layer from being inhibited while exhibiting the antioxidant function for the Al layer. it can.

  In the present invention, the antioxidant layer is preferably formed of a material that can be eutectic with Al or can be diffused into the Al layer. Thereby, eutectic bonding or diffusion bonding between the first connecting metal layer and the second connecting metal layer can be effectively promoted.

  Furthermore, in the present invention, in the above, it is preferable that a portion of the same material as that of the antioxidant layer is formed on at least a bonding surface side of the second connection metal layer with the antioxidant layer. Thereby, the 1st connection metal layer and the 2nd connection metal layer can be joined more firmly.

Moreover, the manufacturing method of the MEMS sensor in the present invention is as follows.
A first substrate that is laminated in the order of a support substrate, an intermediate layer, and a functional layer, and a wiring that has a conduction path between the movable electrode portion and the fixed electrode portion that are formed in the functional layer so as to face the functional layer A substrate,
Forming a bonding layer fixedly supported by the intermediate layer on the functional layer;
Forming a first connection metal layer on the surface of the bonding layer, forming a second connection metal layer on the surface of the wiring board;
At this time, at least one of the first connection metal layer and the second connection metal layer is formed to have an Al layer, and further, the other connection metal layer of the Al layer Forming a coating layer of the same material as the other connecting metal layer on the opposing surface and having a thickness smaller than that of the other connecting metal layer;
Eutectic bonding or diffusion bonding the first connection metal layer and the second connection metal layer;
It is characterized by having.

  As a result, the eutectic or diffusion generated between the Al layer and the coating layer is caused by the reaction start trigger (the active point of the reaction start) of the eutectic bonding or diffusion bonding between the first connecting metal layer and the second connecting metal layer. Therefore, the bonding strength between the first connection metal layer and the second connection metal layer can be improved.

  In the present invention, it is preferable to form a recess that is recessed in a direction away from the surface of the Al layer with respect to the other connection metal layer, and to form the coating layer at least in the recess.

  Or in this invention, it is preferable to form the convex part which protrudes toward the said other connection metal layer from the surface of the said Al layer, and to form the said coating layer in the said surface located at the bottom of the said convex part at least.

  As described above, the bonding strength between the first connection metal layer and the second connection metal layer can be more effectively improved, and the mechanical strength of the MEMS sensor can be further improved.

  According to the MEMS sensor and the manufacturing method thereof of the present invention, the oxidation of the bonding surface of the Al layer formed on at least one of the first connection metal layer and the second connection metal layer can be suppressed, and the first connection metal layer And the bonding strength between the second connection metal layer can be improved.

The top view which shows the separation pattern of the movable electrode part of the MEMS sensor of embodiment of this invention, a fixed electrode part, and a frame body layer, FIG. FIG. It is sectional drawing which shows the laminated structure of a MEMS sensor, and is equivalent to sectional drawing in the IV-IV line of FIG. Cross-sectional view of the MEMS sensor before bonding (in FIG. 4 and FIG. 5, the arrangement configuration of each layer is upside down), The expanded sectional view of the 1st connection metal layer and the 2nd connection metal layer before joining in this embodiment, The expanded sectional view of the 1st connection metal layer before joining in the embodiment different from Drawing 6, and the 2nd connection metal layer, The expanded sectional view of the 1st connection metal layer at the time of joining which shows a desirable example of this embodiment, and the 2nd connection metal layer, The expanded sectional view of the 1st connection metal layer before joining which shows a desirable example of this embodiment, and the 2nd connection metal layer, The expanded sectional view of the 1st connection metal layer before joining which shows a desirable example of this embodiment, and the 2nd connection metal layer, The expanded sectional view of the 1st connection metal layer before joining which shows a desirable example of this embodiment, and the 2nd connection metal layer, Sectional drawing which shows embodiment using IC package, Sectional drawing which shows embodiment different from FIG. Partial sectional view of a conventional MEMS sensor, The expanded sectional view which shows the state before joining between the support conduction | electrical_connection part (anchor part) shown in FIG. 14, and a wiring board,

  FIG. 1 shows a MEMS sensor according to an embodiment of the present invention, and is a plan view showing a movable electrode portion, a fixed electrode portion, and a frame layer. In FIG. 1, the support substrate and the wiring substrate are not shown. 2 is an enlarged view of a portion II in FIG. 1, and FIG. 3 is an enlarged view of a portion III. FIG. 4 is a cross-sectional view showing the entire structure of the MEMS sensor, and corresponds to a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a cross-sectional view of the MEMS sensor before bonding. In FIGS. 4 and 5, the arrangement of each layer is upside down. FIG. 6 is an enlarged cross-sectional view of the first connection metal layer and the second connection metal layer before joining in the present embodiment, and FIG. 7 is a diagram illustrating the first connection metal layer before joining in the embodiment different from FIG. It is an expanded sectional view of the 2nd connection metal layer.

  As shown in FIG. 4, in the MEMS sensor, an SOI layer (functional layer) 10 is sandwiched between the support substrate 1 and the wiring substrate 2. Each part of the support substrate 1 and the SOI layer 10 is joined via oxide insulating layers (intermediate layers) 3a, 3b, 3c.

  The support substrate 1, the SOI layer 10, and the oxide insulating layers 3a, 3b, and 3c are formed by finely processing an SOI (Silicon on Insulator) substrate (first substrate).

  In the SOI layer 10, a first fixed electrode portion 11, a second fixed electrode portion 13, a movable electrode portion 15, and a frame body layer 25 are formed separately. Further, a part of the oxide insulating layer is removed to form oxide insulating layers 3a, 3b, 3c separated from each other.

  As shown in FIG. 1, the planar shape of the SOI layer 10 is 180 degrees rotationally symmetric with respect to the center (centroid) O, and the vertical direction (Y direction) with respect to a line passing through the center O and extending in the X direction. ).

  As shown in FIG. 1, the first fixed electrode portion 11 is provided on the Y1 side from the center O. In the first fixed electrode portion 11, a square support conduction portion (anchor portion) 12 is integrally formed at a position approaching the center O. As shown in FIG. 4, the support conducting portion 12 is fixed to the surface 1a of the support substrate 1 by an oxide insulating layer 3a. In the first fixed electrode part 11, only the support conduction part 12 is fixed to the surface 1a of the support substrate 1 by the oxide insulation layer 3a, and the other part is an oxide insulation layer between the support substrate 1 and the other part. As a result of the removal, a gap having a distance corresponding to the thickness of the oxide insulating layer 3a is formed between the support substrate 1 and the surface 1a.

  As shown in FIG. 1, the first fixed electrode portion 11 has an electrode support portion 11 a having a certain width dimension extending linearly from the support conducting portion 12 in the Y1 direction. A plurality of counter electrodes 11b are integrally formed on the X1 side of the electrode support portion 11a, and a plurality of counter electrodes 11c are integrally formed on the X2 side of the electrode support portion 11a. FIG. 2 shows one counter electrode 11c. Each of the plurality of counter electrodes 11c extends linearly in the X2 direction, and the width dimension in the Y direction is constant. The plurality of counter electrodes 11c are arranged in a comb-like shape with a certain interval in the Y direction. The other counter electrode 11b extending to the X1 side and the counter electrode 11c extending in the X2 direction have a bilaterally symmetric shape with respect to a line extending in the Y direction through the center O.

  A second fixed electrode portion 13 is provided on the Y2 side from the center O. The second fixed electrode portion 13 and the first fixed electrode portion 11 are symmetrical in the vertical direction (Y direction) with respect to a line extending in the X direction through the center O. That is, the second fixed electrode portion 13 has a rectangular support conduction portion (anchor portion) 14 provided at a position approaching the center O, and a constant width dimension extending linearly from the support conduction portion 14 in the Y2 direction. Electrode support portion 13a. A plurality of counter electrodes 13b extending integrally from the electrode support portion 13a are provided on the X1 side of the electrode support portion 13a, and a plurality of counter electrodes 13c extending integrally from the electrode support portion 13a are provided on the X2 side of the electrode support portion 13a. Is provided.

  As shown in FIG. 3, the counter electrode 13c extends linearly in the X2 direction, has a constant width dimension, and is formed in parallel with each other at a constant interval in the Y direction. Similarly, the counter electrode 13b on the X1 side also linearly extends in the X1 direction with a constant width dimension, and extends in parallel in the Y direction at constant intervals.

  In the second fixed electrode portion 13 as well, only the support conduction portion 14 is fixed to the surface 1a of the support substrate 1 through the oxide insulating layer 3a. The other portions of the electrode support portion 13a and the counter electrodes 13b and 13c are removed from the surface 1a of the support substrate 1, and the electrode support portion 13a and the counter electrodes 13b and 13c are supported. A gap having an interval corresponding to the thickness of the oxide insulating layer is formed between the substrate 1 and the surface 1a.

  The SOI layer 10 shown in FIG. 1 has a movable area inside the rectangular frame layer 25, and in the movable area, a portion excluding the first fixed electrode portion 11 and the second fixed electrode portion 13 is a movable electrode portion. It is 15. The movable electrode portion 15 is formed separately from the first fixed electrode portion 11, the second fixed electrode portion 13, and the frame body layer 25.

  As shown in FIG. 1, the movable electrode portion 15 has a first support arm portion 16 extending in the Y1-Y2 direction on the X1 side with respect to the center O, and at a position close to the X1 side of the center O. In addition, a rectangular support conduction portion (anchor portion) 17 formed integrally with the first support arm portion 16 is provided. The movable electrode portion 15 has a second support arm portion 18 extending in the Y1-Y2 direction on the X2 side with respect to the center O, and the second support arm portion is positioned closer to the X2 side of the center O. A square support conduction part (anchor part) 19 formed integrally with the reference numeral 18 is provided.

  The portion sandwiched between the first support arm portion 16 and the second support arm portion 18 and the portion excluding the first fixed electrode portion 11 and the second fixed electrode portion 13 is the weight portion 20. Yes. The edge portion on the Y1 side of the weight portion 20 is supported by the first support arm portion 16 via the elastic support portion 21 and supported by the second support arm portion 18 via the elastic support portion 23. . The edge portion on the Y1 side of the weight portion 20 is supported by the first support arm portion 16 via the elastic support portion 22 and supported by the second support arm portion 18 via the elastic support portion 24. Yes.

  On the Y1 side from the center O, a plurality of movable counter electrodes 20a extending from the X1 side edge of the weight portion 20 to the X2 side are integrally formed, and from the X2 side edge of the weight portion 20 to the X1 side. A plurality of movable counter electrodes 20b extending are integrally formed. As shown in FIG. 2, the movable counter electrode 20b formed integrally with the weight portion 20 is opposed to the side on the Y2 side of the counter electrode 11c of the first fixed electrode portion 11 via a distance δ1 when stationary. ing. Similarly, the movable counter electrode 20a on the X1 side is also opposed to the side on the Y2 side of the counter electrode 11b of the first fixed electrode portion 11 via a distance δ1 when stationary.

  The weight portion 20 is integrally formed with a plurality of movable counter electrodes 20c extending in parallel to the X2 direction from the edge portion on the X1 side on the Y2 side from the center O, and in the X1 direction from the edge portion on the X2 side. A plurality of movable counter electrodes 20d extending in parallel are integrally formed.

  As shown in FIG. 3, the movable counter electrode 20d is opposed to the side on the Y1 side of the counter electrode 13c of the second fixed electrode portion 13 via a distance δ2 when stationary. This is the same between the movable counter electrode 20c on the X1 side and the counter electrode 13b. The opposing distances δ1 and δ2 at rest are designed to have the same dimensions.

  As shown in FIG. 4, the support conduction portion 17 that is continuous with the first support arm portion 16 and the surface 1 a of the support substrate 1 are fixed via the oxide insulating layer 3 b, and the second support arm portion 18 is attached to the second support arm portion 18. The continuous support conduction part 19 and the surface 1a of the support substrate 1 are also fixed via the oxide insulating layer 3b. In the movable electrode portion 15, only the support conduction portion 17 and the support conduction portion 19 are fixed to the support substrate 1 by the oxide insulating layer 3b, and other portions, that is, the first support arm portion 16 and the second support portion. The arm portion 18, the weight portion 20, the movable counter electrodes 20a, 20b, 20c, and 20d and the elastic support portions 21, 22, 23, and 24 have the oxide insulating layer between the surface 1a of the support substrate 1 removed, A gap having an interval corresponding to the thickness dimension of the oxide insulating layer 3 b is formed between these portions and the surface 1 a of the support substrate 1.

  The elastic support portions 21, 22, 23, and 24 are formed so as to form a meander pattern with thin leaf spring portions. As the elastic support portions 21, 22, 23, and 24 are deformed, the weight portion 20 is movable in the Y1 direction or the Y2 direction.

  As shown in FIG. 1, the frame layer 25 is formed by cutting the SOI layer 10 into a square frame shape. An oxide insulating layer 3 c is left between the frame layer 25 and the surface 1 a of the support substrate 1. The oxide insulating layer 3 c is provided so as to surround the entire outer periphery of the movable region of the movable electrode portion 15.

  The manufacturing method of the SOI layer 10 having the shape shown in FIGS. 1 and 4 includes a first fixed electrode portion 11, a second fixed electrode portion 13, a movable electrode portion 15 and a frame on the surface of the SOI layer 10 before processing. A resist layer covering the layer 25 is formed, and a portion of the SOI layer exposed from the resist layer is removed by ion etching means such as deep RIE using high-density plasma, and the first fixed electrode portion 11, the second fixed electrode portion 11, The fixed electrode portion 13, the movable electrode portion 15, and the frame layer 25 are separated from each other.

  At this time, a large number of fine holes are formed by the deep RIE in all regions except the support conductive portions 12, 14, 17, 19 and the frame layer 25. 2 and FIG. 3 illustrate a minute hole 11d formed in the counter electrode 11c, a minute hole 13d formed in the counter electrode 13c, and a minute hole 20e formed in the weight portion 20.

After pattern processing by deep RIE or the like, a selective isotropic etching process that can dissolve the oxide insulating layer (SiO ₂ layer) without dissolving silicon is performed. At this time, the etching solution penetrates into the groove where the respective parts of the SOI layer 10 are separated, and further penetrates into the fine hole, thereby removing the oxide insulating layer.

  As a result, the oxide insulating layers 3a, 3b, 3c are left only between the support conductive portions 12, 14, 17, 19, and the frame layer 25 and the surface 1a of the support substrate 1, and the insulating layers are left in other portions. Is removed.

  The support substrate 1 has a thickness dimension of about 0.2 to 0.7 mm, the SOI layer 10 has a thickness dimension of about 10 to 30 μm, and the oxide insulating layers 3a, 3b, and 3c have a thickness of about 1 to 3 μm. is there.

The silicon substrate 5 constituting the wiring substrate 2 is formed with a thickness dimension of about 0.2 to 0.7 mm. An insulating layer 30 is formed on the surface 5 a of the silicon substrate 5. The insulating layer 30 is an inorganic insulating layer such as SiO ₂ , SiN or Al ₂ O ₃ and is formed by a sputtering process or a CVD process. As the inorganic insulating layer, a material is selected whose difference in thermal expansion coefficient from the silicon substrate is smaller than the difference in thermal expansion coefficient between the conductive metal constituting the connection metal layer and the silicon substrate. Preferably, SiO ₂ or SiN having a relatively small difference in thermal expansion coefficient from the silicon substrate is used.

  As shown in FIG. 4, a second connection metal layer 31 facing the support conduction portion 12 of the first fixed electrode portion 11 is formed on the surface of the insulating layer 30, and the second fixed electrode portion 13 is similarly formed. A second connection metal layer 31 (not shown) facing the support conduction portion 14 is formed. Further, a second connection metal layer 32 that faces one support conduction portion 17 of the movable electrode portion 15 is formed on the surface of the insulating layer 30, and similarly, a second connection that faces the other support conduction portion 19. A metal layer 32 (not shown) is also formed.

  A second seal connection metal layer 33 is formed on the surface of the insulating layer 30 so as to face the surface of the frame body layer 25. The second seal connection metal layer 33 is formed of the same conductive metal material as the second connection metal layers 31 and 32. The second seal connection metal layer 33 is formed in a quadrangular shape so as to face the frame body layer 25 and is formed so as to surround the entire periphery of the movable region at the outer periphery of the movable region of the movable electrode portion 15. .

  Inside the insulating layer 30, a lead layer 34 that conducts to one second connection metal layer 31 and a lead layer 35 that conducts to the other second connection metal layer 32 are provided. The lead layers 34 and 35 are made of Al (aluminum). The plurality of lead layers 34 and 35 are individually connected to the second connection metal layers 31 and 32, respectively. Each of the lead layers 34 and 35 passes through the inside of the insulating layer 30 and traverses the portion where the second seal connection metal layer 33 is formed without contacting the second seal connection metal layer 33. Then, it extends to the outside of the region surrounded by the second seal connection metal layer 33. The wiring board 2 is provided with connection pads 36 that are electrically connected to the lead layers 34 and 35 outside the region. The connection pad 36 is made of a conductive material such as Al (aluminum) or Au (gold).

  In the insulating layer 30, the surface on which the second connection metal layers 31 and 32 are formed and the surface on which the second seal connection metal layer 33 is formed are located on the same plane. A recess 38 is formed in the insulating layer 30 toward the surface 5a of the silicon substrate 5 in a region where the second connection metal layers 31 and 32 and the second seal connection metal layer 33 are not formed. . The recess 38 is formed in all portions of the insulating layer 30 other than the surface facing the support conducting portions 12, 14, 17, 19 and the frame body layer 25. Further, the recess 38 is formed to a depth halfway inside the insulating layer 30 so that the lead layers 34 and 35 are not exposed.

  As shown in FIG. 4, the first connection metal layer 41 facing the second connection metal layer 31 is formed on the surfaces of the support conductive portions 12 and 14 of the SOI layer 10. A first connection metal layer 42 facing each second connection metal layer 32 is formed on the surface 19 by a sputtering process. Furthermore, a first seal connection metal layer 43 that faces the second seal connection metal layer 33 is formed on the surface of the frame layer 25. The first seal connection metal layer 43 is simultaneously formed of the same metal material as the first connection metal layers 41 and 42.

  As shown in FIG. 5, the second connection metal layer 31 and the first connection metal layer 41 face each other, the second connection metal layer 32 and the first connection metal layer 42 face each other, and the second connection metal layer 32 and the first connection metal layer 42 face each other. The seal connection metal layer 33 and the first seal connection metal layer 43 face each other. And between the support substrate 1 and the silicon substrate 5 is pressurized, heating. As a result, the second connection metal layer 31 and the first connection metal layer 41 are eutectic bonded or diffusion bonded, and the second connection metal layer 32 and the first connection metal layer 42 are eutectic bonded or diffused. Join. By the eutectic bonding or diffusion bonding of the second connection metal layers 31, 32 and the first connection metal layers 41, 42, the support conductive portions 12, 14, 17, 19 are converted into the oxide insulating layers 3 a, 3 b and the insulating layer 30. The second connection metal layers 31 and 31 and the support conductive portions 12 and 14 are individually connected to each other, and the second connection metal layers 32 and 32 and the support conductive portion 17 are individually connected. , 19 are individually connected.

  At the same time, the second seal connection metal layer 33 and the first seal connection metal layer 43 are eutectic bonded or diffusion bonded. By this eutectic bonding or diffusion bonding, the frame layer 25 and the insulating layer 30 are firmly fixed, and a metal seal layer 45 surrounding the entire periphery of the movable region of the movable electrode portion 15 is formed.

  As shown in the partially enlarged view of FIG. 6, in the present embodiment, for example, the first connection metal layer 41 formed on the surface 12a of the support conductive portion 12 includes an Al layer 51 formed of Al (aluminum). .

  As shown in FIG. 6, an antioxidant layer 52 is formed on the surface 51 a of the Al layer 51. For example, the antioxidant layer 52 can be formed by sputtering. The antioxidant layer 52 is preferably formed of a material that can be eutectic with Al or can diffuse into the Al layer. Specifically, the antioxidant layer 52 is preferably formed of any one of Ge, Mg, and Zn.

  In this embodiment, since the antioxidant layer 52 is formed on the surface 51a of the Al layer 51, natural oxidation of the surface 51a of the Al layer 51 can be effectively prevented.

  In the present embodiment, the second connection metal layer 31 is preferably made of the same material as the antioxidant layer 52. As a preferred example, the antioxidant layer 52 and the second connection metal layer 31 are both formed of Ge (germanium).

  As described above, after the first connecting metal layer 41 and the second connecting metal layer 31 are formed, the first connecting metal layer 41 and the second connecting metal layer 31 are heated and pressurized while being shared. Crystal bonding or diffusion bonding.

  In this embodiment, since the antioxidant layer 52 is formed on the surface 51a of the Al layer 51 constituting the first connection metal layer 41, a natural oxide film is formed on the bonding surface of the first connection metal layer 41. Can be suppressed as compared with the prior art. For this reason, deep etching (over-etching) for completely removing the natural oxide layer is not necessary before the bonding step, and it is sufficient to perform a cleaning step for removing organic substances attached to the bonding surface. . In the cleaning process, an existing method used for manufacturing a normal semiconductor element can be used. Conventionally, since the natural oxide layer is etched away, the film thickness dimension of the first connection metal layer is likely to vary, but in this embodiment, the film thickness variation of the first connection metal layer 41 can be reduced. .

  In the embodiment shown in FIG. 6, the antioxidant layer 52 is formed with a thin film thickness that allows the Al layer 51 and the second connection metal layer 31 to be eutectic bonded or diffusion bonded. Specifically, the film thickness of the antioxidant layer 52 is preferably in the range of 50 to 500 mm. By setting the thickness of the antioxidant layer 52 to 50 mm or more, the antioxidant effect on the Al layer 51 can be exhibited. Moreover, eutectic bonding or diffusion bonding between the Al layer 51 and the second connection metal layer 31 is not hindered by setting the thickness of the antioxidant layer 52 to 500 mm or less.

  In the present embodiment, as described above, the antioxidant layer 52 is formed of a material that can be eutectic with Al or can be diffused into the Al layer. Thereby, eutectic bonding or diffusion bonding between the first connection metal layer 41 and the second connection metal layer 31 can be effectively promoted.

  Moreover, in the present embodiment, as described above, the second connection metal layer 31 is formed of the same material as the antioxidant layer 52. Therefore, the eutectic temperature and diffusion temperature of the antioxidant layer 52 and the Al layer 51 and the eutectic temperature and diffusion temperature of the second connection metal layer 31 and the Al layer 51 can be made the same, and the first connection metal layer Eutectic bonding or diffusion bonding of 41 and the second connecting metal layer 31 can be promoted more effectively.

  As described above, in the present embodiment, natural oxidation of the Al layer 51 is suppressed, and the first connection metal layer 41 and the second connection metal layer 31 can be appropriately eutectic bonded or diffusion bonded, and both the connection metals The bonding strength between the layers 31 and 41 can be improved. Therefore, the mechanical strength of the MEMS sensor can be improved.

  Conventionally, it has been necessary to completely remove the natural oxidation layer of the Al layer 51. However, in this embodiment, natural oxidation of the bonding surface of the first connection metal layer 41 can be suppressed. No natural oxidation removal step is necessary, and conventionally, it was necessary to move to the bonding step immediately after removing the natural oxide layer, but in this embodiment, the oxidation prevention layer 52 is provided. Therefore, it is possible to give a time margin until the process shifts to the joining process as compared with the conventional case. Therefore, the manufacturing process can be simplified as compared with the conventional case, and the bonding condition margin can be improved.

  In FIG. 7, the second connection metal layer 31 is formed of a laminated structure of an Al layer 53 and an antioxidant layer 54 formed on the surface 53a. In this embodiment, the antioxidant layers 52 and 54 are preferably formed of the same material. For example, the antioxidant layers 52 and 54 are both made of Ge.

  The antioxidant layer 54 formed on the second connection metal layer 31 is formed thicker than the antioxidant layer 52 formed on the first connection metal layer 41. This increases the amount of eutectic material or diffusion material for forming a eutectic with Al or diffusing into the Al layer, and eutectic bonding between the first connecting metal layer 41 and the second connecting metal layer 31 or This is to effectively promote diffusion bonding.

  In the form shown in FIG. 7, the bonding state between the Al layer 53 formed on the second connection metal layer 31 and the lead layer 34 also formed of Al can be improved. In addition, Al is one of the most suitable materials as a pad connected to the lead layer 34 because of its low resistance and excellent electrical conductivity. Therefore, it is preferable that the Al layer 53 is also provided on the second connection metal layer 31 side.

  As described above, there are Al—Mg, Al—Zn, Al—Ge, and the like as a combination of metals capable of eutectic bonding or diffusion bonding with Al. By combining these metals, it becomes possible to perform bonding at a relatively low temperature of 450 ° C. or lower, which is a temperature lower than the melting point of each metal.

  In FIG. 6, the first connection metal layer 41 is formed with a laminated structure of an Al layer 51 and an antioxidant layer 52, and the second connection metal layer 31 has a single-layer structure. May be a single layer (for example, Ge), and the second connection metal layer 31 may be formed of a laminated structure of an Al layer 51 and an antioxidant layer 52. The same applies to FIG.

  In the above description, the joint structure of the support conductive portion 12 has been described, but the other support conductive portions 14, 17, and 19 have the same joint structure.

  Further, as in the embodiment of FIG. 4, a metal seal layer 45 is formed on the frame body layer 25 by eutectic bonding or diffusion bonding of the first seal connection metal layer 43 and the second seal connection metal layer 33. In the form, it is preferable that the first seal connecting metal layer 43 and the second seal connecting metal layer 33 are also formed in the form shown in FIGS. This is preferable because a strong metal sealing layer 45 can be formed and the sealing performance can be improved.

  The above-described MEMS sensor has a structure in which the SOI substrate and the wiring substrate 2 are stacked, and can be thinned as a whole. In particular, conventionally, the natural oxide layer formed on the surface of the connection metal layer made of Al was likely to vary in the thickness of the connection metal layer, but in this embodiment, the conventional etching process is not required. Therefore, variation in the thickness of the MEMS sensor can be suppressed as compared with the conventional case.

  Further, the bonding layer composed of the second connection metal layers 31 and 32 and the first connection metal layers 41 and 42 is thin and has a small area, and the support conductive portions 12, 14, 17 and 19 and the support substrate 1 are connected to each other. It joins through the oxide insulating layers 3a and 3b of an inorganic insulating material. Therefore, even if the ambient temperature becomes high, the thermal stress of the bonding layer hardly affects the support structure of the support conductive portions 12, 14, 17, and 19, and the fixed electrode portions 11 and 13 and the movable electrode portion 15 due to the thermal stress. It is hard to generate distortion.

  Similarly, the metal seal layer 45 surrounding the movable region of the movable electrode portion 15 is a bonding layer formed thinly between the frame body layer 25 and the insulating layer 30, and the frame body layer 25 has a sufficient thickness dimension. Therefore, distortion or the like is unlikely to occur in the support substrate 1 or the silicon substrate 5 formed of silicon due to the thermal stress of the metal seal layer 45.

  FIG. 8 is an enlarged cross-sectional view of the first connection metal layer and the second connection metal layer at the time of joining, showing a preferred example of this embodiment.

  In the embodiment shown in FIG. 8, the first connection metal layer 41 is formed by a laminated structure of an Al layer 51 and a thin Ge layer (covering layer) 55. The second connection metal layer 31 is Ge. In this way, the coating layer made of the same Ge as the second connection metal layer 31 is provided on the surface of the first connection metal layer 41, and the film thickness is formed thinner than that of the second connection metal layer 31.

  The Ge layer 55 formed on the surface of the first connection metal layer 41 suppresses the natural oxidation of the Al layer 51 similarly to the antioxidant layer 52 described with reference to FIGS.

  Then, the eutectic or diffusion that occurs between the Al layer 51 and the Ge layer 55 during bonding in the heated / pressurized state shown in FIG. 8 is the same as that of the first connecting metal layer 41 and the second connecting metal layer 31. It can be used as a reaction start trigger (active point for reaction start) in crystal bonding or diffusion bonding. Therefore, the bonding strength between the first connection metal layer 41 and the second connection metal layer 31 can be appropriately improved. In FIG. 6, the same phenomenon as described above occurs.

  In addition, the Ge layer 55 plays a role of suppressing the natural oxidation of the Al layer 51. However, before the Ge layer 55 is formed, the Al layer 51 has a production environment in which a natural oxide layer is formed on the surface thereof. After removing the natural oxide layer formed on the surface of the layer 51, the Ge layer 55 can be formed. Further, after the Ge layer 55 is formed, the surface of the first connection metal layer 41 can be cleaned. Further, since the eutectic or diffusion generated between the Al layer 51 and the Ge layer 55 becomes a reaction start trigger (active point of reaction start), there is a slight oxide film on the surface of the first connection metal layer 41. Also, the oxide film can be destroyed, and the reaction between the first connection metal layer 41 and the second connection metal layer 31 can be appropriately promoted.

  6 and 7 and the Ge layer 55 shown in FIG. 8 are all formed over the entire surface of the Al layer 51, a part of the Al layer 51 may be partially exposed. Although natural oxidation is easily promoted in the exposed portion of the Al layer 51, depending on the film thickness of the antioxidant layer 52 and the Ge layer 55 or the heating conditions, the reaction may not be promoted properly without the exposed region of the Al layer 51. is there. In particular, if the phenomenon of the reaction start trigger (reaction start active point) described above is used, even if there is an oxide film, it is considered that the oxide film is destroyed and the reaction is promoted. Even in the exposed form, the bonding strength between the first connection metal layer 41 and the second connection metal layer 31 can be improved as compared with the conventional case.

  In the embodiment shown in FIG. 9, a recess 51 b that is recessed at a substantially central portion of the surface of the Al layer 51 that constitutes the first connection metal layer 41 is formed. A Ge layer 55 is provided in the recess 51b. The film thickness of the Ge layer 55 is sufficiently thinner than the film thickness of the second connection metal layer 31 which is also formed of Ge.

  In the embodiment of FIG. 9, the bonding area between the first connection metal layer 41 and the second connection metal layer 31 is reduced, and thus a unit added between the first connection metal layer 41 and the second connection metal layer 31. The weight per area can be increased, and the bonding strength between the first connection metal layer 41 and the second connection metal layer 31 can be increased more effectively.

  In the embodiment of FIG. 9, the Ge layer 55 is formed only in the recess 51b. The natural oxidation of the Al layer 51 can be more effectively suppressed when the Ge layer 55 is formed so as to cover the entire surface of the Al layer 51. On the other hand, depending on the thickness of the Ge layer 55 and the heating temperature, if there is a Ge layer 55 on the bonding surface 51a of the Al layer 51 to which a load is applied, the second connection metal formed of the same Ge when the weight is applied. There is a possibility that the reaction does not proceed properly with the layer 31. Therefore, in FIG. 9, the Ge layer 55 is formed only in the recess 51b. Although a natural oxide layer is likely to be formed on the bonding surface 51a of the Al layer 51, as described above, a eutectic or diffusion generated between the Al layer 51 and the Ge layer 55 is caused by a reaction start trigger (active point of reaction start). And the load can be concentrated on the bonding surface, so that the bonding strength between the first connection metal layer 41 and the second connection metal layer 31 can be increased more effectively.

  In the embodiment shown in FIG. 10, for example, a protruding portion 56 is formed on the surface 12 a of the support conducting portion 12, and a recessed portion 56 a is formed in a substantially central portion of the protruding portion 56. Then, an Al layer 51 is formed following the surface of the protruding portion 56, and a Ge layer 55 is formed in the recess 51b formed in the Al layer 51.

  In the embodiment shown in FIG. 11, a protruding portion 51 c is formed at a substantially central portion of the surface of the Al layer 51 constituting the first connection metal layer 41. A Ge layer 55 is formed from the side surface of the convex portion 51c to the surface of the Al layer 51 located at the bottom of the convex portion 51c. Also in this embodiment, the joint area between the first connection metal layer 41 and the second connection metal layer 31 is reduced as in FIG. 9. Therefore, the first connection metal layer 41 and the second connection metal layer 31 are reduced. The weight per unit area applied therebetween can be increased, and the bonding strength between the first connection metal layer 41 and the second connection metal layer 31 can be increased more effectively.

  8 to 11 described above, the Ge layer 55 is provided on the surface of the Al layer 51. However, if the second connection metal layer 31 is other than Ge, it is formed on the surface of the Al layer 51 accordingly. The material of the covering layer is also determined. At this time, depending on the material of the coating layer, an oxide film may be easily formed on the surface of the first connection metal layer 41 as compared with the case where the Ge layer 55 is provided. Since the eutectic or diffusion generated between the Al layer 51 and the coating layer becomes the reaction start trigger (active point of reaction start) in the heated / pressurized state as shown in FIG. The bonding strength between the metal layer 41 and the second connection metal layer 31 can be improved.

  In the MEMS sensor according to this embodiment, the overall thickness dimension is substantially determined by the thickness dimension of the support substrate 1 and the silicon substrate 5, the thickness dimension of the SOI layer 10, and the thickness dimension of the insulating layer 30. Since the thickness dimension of each layer can be managed with high accuracy, variations in thickness are less likely to occur. In addition, since the insulating layer 30 is formed with a recess 38 that faces the movable region of the movable electrode portion 15, even if the whole is thin, the movable electrode portion 15 has a movement margin (margin) in the thickness direction. Even if a large acceleration in the thickness direction acts from the outside, the weight portion 20 and the movable counter electrodes 20a, 20b, 20c, and 20d are unlikely to hit the insulating layer 30, and malfunctions are unlikely to occur.

  Further, in the embodiment shown in FIG. 4, the wiring board 2 includes the silicon substrate 5, and the insulating layer 30, the lead layers 34 and 35, and the second connection metal layer 31 on the surface 5 a of the silicon substrate 5. Is done. Therefore, it is possible to reduce the thickness with a simple structure as compared with a mode in which a conduction path with the support conduction portion is ensured by using a through wiring penetrating the silicon substrate as shown in FIG.

  This MEMS sensor can be used as an acceleration sensor that detects acceleration in the Y1 direction or the Y2 direction. For example, when acceleration in the Y1 direction acts on the MEMS sensor, the weight portion 20 of the movable electrode portion 15 moves in the Y2 direction due to the reaction. At this time, the facing distance δ1 between the movable counter electrode 20b and the fixed counter electrode 11c shown in FIG. 2 increases, and the capacitance between the movable counter electrode 20b and the counter electrode 11c decreases. At the same time, the facing distance δ2 between the movable counter electrode 20d and the counter electrode 13c shown in FIG. 3 becomes narrow, and the capacitance between the movable counter electrode 20b and the counter electrode 13c increases.

  A change in acceleration acting in the Y1 direction is detected by detecting a decrease and an increase in capacitance with an electric circuit and obtaining a difference between an output change due to an increase in the facing distance δ1 and an output change due to a decrease in the facing distance δ2. And the magnitude of acceleration can be detected.

  In the present invention, the weight portion 20 of the movable electrode portion 15 moves in the thickness direction in response to the acceleration in the direction orthogonal to the XY plane, and the counter electrodes 11b, 11c of the fixed electrode portions 11, 13 are moved. , 13b, 13c and the movable counter electrode 20a, 20b, 20c in the movable electrode portion 15 are opposed to each other in the thickness direction of the movable electrode portion 15 to change the facing area. You may detect the change of the electrostatic capacitance between counter electrodes.

FIG. 12 is a cross-sectional view showing a MEMS sensor according to still another embodiment.
In this MEMS sensor, an IC package 100 is used instead of the silicon substrate 5. The IC package 100 includes a detection circuit that detects a change in capacitance between the counter electrode and the movable counter electrode.

  The insulating layer 30 is formed on the upper surface 101 of the IC package 100, and the second connecting metal layers 31 and 32 and the second seal connecting metal layer 33 are formed on the surface of the insulating layer 30. The second connection metal layers 31 and 32 are electrically connected to electrode pads or the like appearing on the upper surface 101 of the IC package 100 via connection layers 134 and 135 such as through holes penetrating the insulating layer 30. It is connected to the electrical circuit inside.

  The MEMS sensor shown in FIG. 12 also includes a first connection metal layer and a second connection metal layer that form a bonding structure of the bonding layer (supporting conductive portions 12, 14, 17, 19 and frame body layer 25) with the wiring board. Is formed in any form of FIGS. Therefore, oxidation of the bonding surface of the Al layer provided on at least one of the first connection metal layer and the second connection metal layer can be suppressed, and the bonding strength between the first connection metal layer and the second connection metal layer can be reduced. Can be improved.

FIG. 13 is a cross-sectional view showing a MEMS sensor according to still another embodiment.
In the embodiment shown in FIG. 13, a through wiring layer 28 that is also formed of silicon and penetrates the silicon substrate 27 constituting the wiring substrate 26 is provided. The through wiring layer 28 and the silicon substrate 27 are insulated by an insulating layer 29. As shown in FIG. 13, second connection metal layers 31 and 32 are formed on the surface 27 a of the silicon substrate 27 that is in contact with the through wiring layer 28 and faces the SOI layer 10. The insulating layer 29 covers the surface 27b opposite to the surface facing the SOI layer 10 of the silicon substrate 27. As shown in FIG. 13, a lead layer 37 in contact with the through wiring layer 28 is formed inside the insulating layer 29. Has been.

  The MEMS sensor shown in FIG. 13 also includes a first connection metal layer and a second connection metal layer that form a bonding structure of the bonding layer (supporting conductive portions 12, 14, 17, 19 and frame body layer 25) with the wiring board. Is formed in any form of FIGS. Therefore, oxidation of the bonding area of the Al layer provided on at least one of the first connection metal layer and the second connection metal layer can be suppressed, and the bonding strength between the first connection metal layer and the second connection metal layer can be reduced. Can be improved.

DESCRIPTION OF SYMBOLS 1 Support substrate 2 Wiring board 3a, 3b, 3c Oxide insulating layer 5, 27 Silicon substrate 10 SOI layer 11 1st fixed electrode part 11b, 11c Counter electrode 12 Support conduction | electrical_connection part (anchor part)
13 Second fixed electrode portion 13b, 13c Counter electrode 14 Support conduction portion (anchor portion)
15 Movable electrode portion 16 First support arm portion 17 Support conduction portion (anchor portion)
18 Second support arm portion 19 Support conduction portion (anchor portion)
20 Weight parts 20a, 20b, 20c, 20d Movable counter electrodes 21, 22, 23, 24 Elastic support part 25 Frame layer 28 Penetration wiring layers 29, 30 Insulating layers 31, 32 Second connecting metal layer 33 Second seal Connection metal layer 34, 35 Lead layer 38 Recess 41, 42 First connection metal layer 43 First seal connection metal layer 45 Metal seal layer 51, 53 Al layer 51a Recess 51c Protrusion 52, 54 Antioxidation layer 55 Ge layer 56 Protrusion 100 IC package

Claims (19)

A first substrate that is laminated in the order of a support substrate, an intermediate layer, and a functional layer, and a wiring that has a conduction path between the movable electrode portion and the fixed electrode portion that are formed in the functional layer so as to face the functional layer A substrate,
The functional layer is fixedly supported on the intermediate layer, and a bonding layer bonded to the wiring board is formed,
A first connection metal layer is formed on the surface of the bonding layer, a second connection metal layer is formed on the surface of the wiring board, and the first connection metal layer and the second connection metal layer are shared. Crystal bonding or diffusion bonding,
Of the first connection metal layer and the second connection metal layer, at least one of the connection metal layers is an antioxidant layer formed on the bonding surface of the Al layer and the other connection metal layer of the Al layer. And a MEMS sensor.   2. The MEMS sensor according to claim 1, wherein the antioxidant layer is formed with a film thickness that enables eutectic bonding or diffusion bonding between the Al layer and the second connection metal layer.   The MEMS sensor according to claim 2, wherein the thickness of the antioxidant layer is formed within a range of 50 to 500 mm.   The MEMS sensor according to claim 2, wherein the antioxidant layer is formed of a material that can be eutectic with Al or can be diffused into the Al layer.   5. The MEMS sensor according to claim 4, wherein the second connection metal layer has a portion formed of the same material as that of the antioxidant layer at least on a bonding surface side with the antioxidant layer. A first substrate that is laminated in the order of a support substrate, an intermediate layer, and a functional layer, and a wiring that has a conduction path between the movable electrode portion and the fixed electrode portion that are formed in the functional layer so as to face the functional layer A substrate,
The functional layer is fixedly supported on the intermediate layer, and a bonding layer bonded to the wiring board is formed,
A first connection metal layer is formed on the surface of the bonding layer, a second connection metal layer is formed on the surface of the wiring board, and the first connection metal layer and the second connection metal layer are shared. Crystal bonding or diffusion bonding,
Of the first connection metal layer and the second connection metal layer, one connection metal layer is an Al layer and a coating layer formed on the surface of the Al layer facing the other connection metal layer, Formed with
The MEMS sensor according to claim 1, wherein the covering layer is made of the same material as the other connecting metal layer and is thinner than the other connecting metal layer.   The MEMS sensor according to claim 6, wherein a recess that is recessed from the surface of the Al layer in a direction away from the other connection metal layer is formed, and the coating layer is formed in the recess.   7. The MEMS according to claim 6, wherein a convex portion that protrudes from the surface of the Al layer toward the other connecting metal layer is formed, and the covering layer is formed on the surface that is located at the bottom of the convex portion. Sensor.   The MEMS sensor according to any one of claims 1 to 8, wherein the bonding layer is a support conduction portion connected to each of the movable electrode portion and the fixed electrode portion.   The bonding layer is a frame layer that is formed separately from the movable electrode portion and the fixed electrode portion, and surrounds a movable region of the movable electrode portion, and includes the first connection metal layer and the second connection metal. The MEMS sensor according to any one of claims 1 to 9, wherein a metal seal layer surrounding the outer periphery of the movable region is formed by eutectic bonding or diffusion bonding with the layer.   The wiring board includes a silicon substrate, a lead layer electrically connected to each of the movable electrode portion and the fixed electrode portion embedded in the insulating layer and the insulating layer on the surface of the silicon substrate, The MEMS sensor according to any one of claims 1 to 10, wherein the MEMS sensor is formed including the second connection metal layer. A first substrate that is laminated in the order of a support substrate, an intermediate layer, and a functional layer, and a wiring that has a conduction path between the movable electrode portion and the fixed electrode portion that are formed in the functional layer so as to face the functional layer A substrate,
Forming a bonding layer fixedly supported by the intermediate layer on the functional layer;
Forming a first connection metal layer on the surface of the bonding layer, forming a second connection metal layer on the surface of the wiring board;
At this time, at least one of the first connection metal layer and the second connection metal layer is formed to have an Al layer, and further, the other connection metal layer of the Al layer Forming an antioxidant layer on the bonding surface of
Eutectic bonding or diffusion bonding the first connection metal layer and the second connection metal layer;
A method for manufacturing a MEMS sensor, comprising:   13. The method of manufacturing a MEMS sensor according to claim 12, wherein the antioxidant layer is formed with a film thickness that enables eutectic bonding or diffusion bonding between the Al layer and the second connection metal layer.   The method of manufacturing a MEMS sensor according to claim 13, wherein the thickness of the antioxidant layer is formed within a range of 50 to 500 mm.   15. The method of manufacturing a MEMS sensor according to claim 13, wherein the antioxidant layer is formed of a material that can be eutectic with Al or can be diffused into the Al layer.   The method for manufacturing a MEMS sensor according to claim 15, wherein a portion made of the same material as that of the antioxidant layer is formed on at least a bonding surface side of the second connection metal layer with the antioxidant layer. A first substrate that is laminated in the order of a support substrate, an intermediate layer, and a functional layer, and a wiring that has a conduction path between the movable electrode portion and the fixed electrode portion that are formed in the functional layer so as to face the functional layer A substrate,
Forming a bonding layer fixedly supported by the intermediate layer on the functional layer;
Forming a first connection metal layer on the surface of the bonding layer, forming a second connection metal layer on the surface of the wiring board;
At this time, at least one of the first connection metal layer and the second connection metal layer is formed to have an Al layer, and further, the other connection metal layer of the Al layer Forming a coating layer of the same material as the other connecting metal layer on the opposing surface and having a thickness smaller than that of the other connecting metal layer;
Eutectic bonding or diffusion bonding the first connection metal layer and the second connection metal layer;
A method for manufacturing a MEMS sensor, comprising:   The method of manufacturing a MEMS sensor according to claim 17, wherein a recess that is recessed from the surface of the Al layer in a direction away from the other connection metal layer is formed, and the covering layer is formed at least in the recess.   18. The MEMS sensor manufacturing method according to claim 17, wherein a protrusion projecting from the surface of the Al layer toward the other connection metal layer is formed, and the covering layer is formed at least on the surface positioned at the bottom of the protrusion. Method.

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