MEMS device

Abstract

This micro-electro-mechanical systems (MEMS) device comprises: a base layer comprising a semiconductor; a semiconductor oxide layer comprising a semiconductor oxide film disposed on a main surface of the base layer; a device layer comprising a semiconductor connected to the base layer via the semiconductor oxide layer; a cap layer connected to the device layer; a movable part disposed in an internal space surrounded by the base layer, the semiconductor oxide layer, the device layer, and the cap layer; a protective layer disposed on a main surface of the cap layer; an electrode pad disposed on the main surface of the cap layer or the surface of the protective layer so as to output an electrical signal based on the movement of the movable part; and a lateral-surface metal conductor film disposed on the lateral surfaces of the cap layer.

Description

MEMS device

[0001] The present disclosure relates to a MEMS (Micro Electro Mechanical Systems) device, and more particularly to a MEMS device in which a main body of the MEMS device (MEMS main body) and a control IC are connected by bumps.

[0002] Patent Document 1 describes a semiconductor device having a semiconductor chip, a wiring layer provided on the functional surface (main surface) of the semiconductor chip, connection terminals formed of solder balls (bumps) or the like electrically connected to the wiring layer, and a mounting substrate for mounting the semiconductor chip by flip-chip bonding via the connection terminals. In this semiconductor device, an underfill resin is filled between the semiconductor chip and the mounting substrate (a space where the connection terminals are not present).

[0003] JP 2010-34519 A

[0004] Conventionally, when connecting a MEMS body to a control IC (mounting substrate) using bumps, a gap (a space where no bumps exist) can form between the MEMS body and the control IC, resulting in insufficient connection strength between the MEMS body and the control IC.

[0005] Therefore, it is conceivable to improve the connection strength by filling the gap between the MEMS body and the control IC with underfill (resin), as is done in the semiconductor device described in Patent Document 1. However, in this case, there is a possibility that the temperature characteristics of the MEMS device will deteriorate due to stress caused by the difference in the thermal expansion coefficient between the semiconductor and resin that make up the MEMS body.

[0006] A MEMS device according to one aspect of the present disclosure comprises a base layer made of a semiconductor, a semiconductor oxide layer made of a semiconductor oxide film arranged on a main surface of the base layer, a device layer made of a semiconductor connected to the base layer via the semiconductor oxide layer, a cap layer connected to the device layer, a movable part arranged in an internal space surrounded by the base layer, the semiconductor oxide layer, the device layer, and the cap layer, a protective layer arranged on the main surface of the cap layer, an electrode pad arranged on the main surface of the cap layer or on the surface of the protective layer so as to output an electrical signal based on the movement of the movable part, and a side metal conductor film arranged on a side surface of the cap layer.

[0007] According to one aspect of the present disclosure, there is provided a MEMS device comprising: a control IC; a mounting pad disposed on the control IC; a bump disposed on the mounting pad; and a MEMS body mounted to the control IC via the mounting pad and the bump. The MEMS body comprises: a base layer made of a semiconductor; a semiconductor oxide layer formed on a principal surface of the base layer; a device layer made of a semiconductor connected to the base layer via the semiconductor oxide layer; a cap layer connected to the device layer; a movable part disposed in an internal space surrounded by the base layer, the semiconductor oxide layer, the device layer, and the cap layer; a protective layer disposed on the principal surface of the cap layer; electrode pads disposed on the principal surface of the cap layer or on a surface of the protective layer to output an electrical signal based on the movement of the movable part; and a side metal conductor film disposed on a side surface of the cap layer. The bumps are disposed between the mounting pads and the electrode pads. The MEMS device further includes a connection electrode arranged on the control IC, and a mounting metal conductor film connected to the side metal conductor film and the connection electrode so as to cover the mounting pad and the bump sandwiched between the electrode pad and the cap layer or the protective layer and the control IC.

[0008] The MEMS device of the present disclosure has the advantage of being able to improve connection strength while maintaining temperature characteristics.

[0009] Fig. 1 is a cross-sectional view of a MEMS (Micro Electro Mechanical Systems) main body constituting a MEMS device according to an embodiment of the present disclosure. Fig. 2A is a cross-sectional view of the same MEMS device. Fig. 2B is a top view of the same MEMS device. Fig. 3 is a cross-sectional view of a MEMS main body constituting a MEMS device according to a first modified example. Fig. 4 is a cross-sectional view of the same MEMS device. Fig. 5 is a cross-sectional view of a MEMS main body constituting a MEMS device according to a second modified example.

[0010] (1) Overview First, an overview of a MEMS (Micro Electro Mechanical Systems) device 100 according to an embodiment of the present disclosure will be described with reference to FIG.

[0011] The MEMS device 100 is a device (MEMS body 1) that makes it possible to improve the connection strength (for example, between the control IC 10 and the mounting metal conductor film 30) without filling with underfill by arranging a side metal conductor film 18 on the side surface 152 of the cap layer 15.

[0012] 1 , the MEMS device 100 includes a base layer 11, a semiconductor oxide layer 12, a device layer 13, a cap layer 15, a movable portion 13A, a protective layer 16, an electrode pad 17, and a side metal conductor film 18. The base layer 11, the semiconductor oxide layer 12, the device layer 13, the cap layer 15, the protective layer 16, and the electrode pad 17 are stacked in a stacking direction Ds. These layers are stacked so that the main surfaces of these layers facing in a direction parallel to the stacking direction Ds face or abut against each other. The side surfaces of these layers are connected to the main surfaces and face in a direction intersecting the stacking direction Ds, and in this embodiment, face in a direction perpendicular to the stacking direction Ds.

[0013] (1-1) Base Layer The base layer 11 is a layer made of a semiconductor. The semiconductor that constitutes the base layer 11 is silicon (Si).

[0014] (1-2) Semiconductor Oxide Layer The semiconductor oxide layer 12 is a layer made of a semiconductor oxide film, and is also called a buried oxide film. In this embodiment, the semiconductor oxide film is made of silicon dioxide (SiO ２ ) thin film.

[0015] 1, the semiconductor oxide layer 12 is disposed on the main surface 111 of the base layer 11. The main surface 111 here refers to one of a pair of main surfaces intersecting the stacking direction (the upper surface in FIG. 1). Disposing the semiconductor oxide layer 12 on the main surface 111 of the base layer 11 means that the semiconductor oxide layer 12 is stacked on the main surface 111 side of the base layer 11.

[0016] 1, the semiconductor oxide layer 12 has a central portion (a range that becomes part of the internal space SP1) corresponding to the movable portion 13A removed, thereby expanding the internal space SP1.

[0017] (1-3) Device Layer The device layer 13 is a layer made of a semiconductor. The semiconductor constituting the device layer 13 is silicon. The device layer 13 is connected to the base layer 11 via the semiconductor oxide layer 12. The device layer 13 is connected to the base layer 11 via the semiconductor oxide layer 12, which means that the device layer 13 is further stacked on the semiconductor oxide layer 12 on the main surface 111 side of the base layer 11.

[0018] 1, the central portion of the device layer 13 corresponding to the movable portion 13A is removed, thereby ensuring an internal space SP1.

[0019] (1-4) Capping Layer The capping layer 15 is a layer connected to the device layer 13. The capping layer 15 being connected to the device layer 13 means that the capping layer 15 is further stacked on the device layer 13 on the main surface 111 side of the base layer 11.

[0020] In this embodiment, the cap layer 15 is a layer made of a semiconductor, and the semiconductor that constitutes the cap layer 15 is silicon.

[0021] (1-5) Movable Part and Internal Space The movable part 13A is a member disposed in the internal space SP1. The internal space SP1 is a space surrounded by the base layer 11, the semiconductor oxide layer 12, the device layer 13, and the cap layer 15.

[0022] The movable portion 13A is capable of moving (displacing) relative to other elements of the MEMS device 100, i.e., the base layer 11, the semiconductor oxide layer 12, the device layer 13, the cap layer 15, and the protective layer 16. The movable portion 13A is displaced in response to, for example, acceleration or deceleration of the MEMS device 100.

[0023] The movable portion 13A in this embodiment is a movable electrode. The movable portion 13A is electrically connected to the control IC 10 via a TSV (Through Silicon Via) 13B that penetrates the cap layer 15 and the like, and a bump 20 (see "(3-1-2) Mounting Pad and Bump") that is disposed between the TSV 13B and the mounting pad 101.

[0024] The internal space SP1 that houses the movable part 13A is also called a cavity. The internal space SP1 is preferably maintained in a vacuum state in order to reduce the viscous resistance that the movable part 13A experiences from the air in the internal space SP1 in response to the displacement of the MEMS device 100.

[0025] (1-6) Protective Layer The protective layer 16 is a layer disposed on the main surface 151 of the cap layer 15. The main surface 151 here refers to the main surface (the upper surface in FIG. 1 ) of the pair of main surfaces of the cap layer 15 that intersect with the stacking direction, opposite the internal space SP1. Disposing the protective layer 16 on the main surface 151 of the cap layer 15 means that the protective layer 16 is further laminated on the semiconductor oxide layer 12, the device layer 13, the cap layer 15, etc., which are laminated on the main surface 111 side of the base layer 11. The protective layer 16 in this embodiment is a silicon nitride film.

[0026] (1-7) Electrode Pad The electrode pad 17 is a member disposed on the main surface 151 of the cap layer 15 or the surface 161 of the protective layer 16 so as to output an electrical signal based on the movement of the movable part 13A. In this embodiment, the electrode pad 17 includes a fixed electrode, and the electrical signal is a signal indicating the acceleration of the MEMS device 100.

[0027] More specifically, the relative position of the movable part 13A (movable electrode) with respect to the electrode pad 17 (fixed electrode) changes in accordance with the movement (acceleration / deceleration) of the MEMS device 100. As a result, the capacitance between the fixed electrode and the movable electrode (between the electrodes) changes. The electrode pad 17 outputs an acceleration signal corresponding to this change in the capacitance between the electrodes.

[0028] (1-8) Side-Side Metal Conductor Film The side-side metal conductor film 18 is a metal conductor film disposed on the side surface 152 of the cap layer 15 .

[0029] In this embodiment, the metal conductor film is, for example, an aluminum (Al) film. The side surface metal conductor film 18 is formed by vapor deposition of aluminum onto the side surface 152 of the cap layer 15.

[0030] (1-9) Advantages According to the above configuration, by disposing the side metal conductor film 18 (e.g., an aluminum vapor deposition film) on the side surface 152 of the cap layer 15, it is possible to improve the connection strength between the MEMS body 1 and the control IC 10 without filling with underfill.

[0031] In detail, the above configuration (see FIG. 1) is the configuration of the MEMS main body 1, and the MEMS device 100 may further include, in addition to the MEMS main body 1, a control IC 10, a mounting pad 101 arranged on the control IC 10, a connection electrode 102 arranged on the control IC 10, and a bump 20 arranged between the mounting pad 101 and the electrode pad 17, as shown in FIG. 2A, for example, and the MEMS main body 1 is mounted to the control IC 10 via the mounting pad 101 and the bump 20.

[0032] In the above configuration (for example, the MEMS device 100 shown in Figure 2A), by using a mounting metal conductor film 30 (solder fillet) as shown in Figures 2A and 2B, the side metal conductor film 18 and the connection electrode 102 are connected so as to cover the periphery of the bump 20 sandwiched between the electrode pad 17 and the mounting pad 101 between the cap layer 15 or the protective layer 16 and the control IC 10, thereby improving the connection strength between the MEMS main body 1 and the control IC 10.

[0033] Furthermore, the above configuration can avoid the deterioration of temperature characteristics caused by differences in thermal expansion coefficients, which occurs when underfilling is performed. In other words, the strength of the connection between the MEMS body 1 and the control IC 10 can be improved while maintaining the temperature characteristics of the MEMS body 1.

[0034] Furthermore, in the above configuration, the gap between the MEMS main body 1 and the control IC 10, i.e., the space around the bump 20, is sealed and electromagnetically shielded by the mounting metal conductor film 30, thereby preventing the intrusion of gases such as moisture and oxidizing atmospheres, as well as electromagnetic noise.

[0035] (2) Details Next, details of the MEMS device 100 will be described with reference to FIG.

[0036] (2-1) Details of the Side Metal Conductor Film The side metal conductor film 18 is disposed so as to cover the entire periphery of the side surface 152 of the cap layer 15. The entire periphery here preferably means the entire periphery, but may also mean most of the periphery. The most of the periphery means a portion whose proportion to the periphery is equal to or greater than a threshold value (e.g., 95%, 90%, etc.).

[0037] In this embodiment, the entire periphery of the side surface 152 of the cap layer 15 is covered with the side surface metal conductor film 18 , but there may be slits or holes that are not covered with the side surface metal conductor film 18 .

[0038] In this way, by covering the entire periphery of the side surface 152 of the cap layer 15 with the side surface metal conductor film 18, it is possible to further improve the connection strength.

[0039] (2-2) Bonding Layer As shown in Fig. 1, the MEMS device 100 further includes a bonding layer 14. The bonding layer 14 is a layer made of a bonding material. The bonding material is, for example, a eutectic bonding material such as gold-tin (Au-Sn) or aluminum-germanium (Al-Ge).

[0040] The bonding layer 14 is disposed between the device layer 13 and the cap layer 15. The cap layer 15 is connected to (stacked on) the device layer 13 via the bonding layer 14.

[0041] The bonding layer 14 is interposed between the cap layer 15 and the device layer 13, thereby improving the bonding strength of the cap layer 15 to the device layer 13. The bonding layer 14 also serves to expand the internal space SP1.

[0042] (2-3) Connection of Side Metal Conductor Film to Base Layer and Device Layer The side metal conductor film 18 is further connected to the base layer 11 and the device layer 13 as shown in FIG.

[0043] This allows the base layer 11 and the device layer 13, which are disposed with the semiconductor oxide layer 12 interposed therebetween, to be at the same potential, thereby improving the accuracy of the electrical signal from the MEMS device 100.

[0044] (2-4) Arrangement of Side-Side Metal Conductor Film on Side of Semiconductor Oxide Layer The side-side metal conductor film 18 is further arranged on the side surface 121 of the semiconductor oxide layer 12 so as to cover the entire periphery of the side surface 121. In this way, by covering the side surface 121 of the semiconductor oxide layer 12, in particular by covering the entire periphery of the side surface 121 with the side-side metal conductor film 18, it is possible to improve the connection strength while preventing the external atmosphere from entering the semiconductor oxide layer 12.

[0045] (3) Specific Examples Next, specific examples of the MEMS device 100 will be described with reference to Figures 1, 2A, and 2B. Note that in the following, descriptions of previously mentioned matters will be omitted or simplified.

[0046] The MEMS device 100 in this specific example (see Figures 2A and 2B) is a device in which the connection strength between the MEMS body 1 and the control IC 10 is improved using a mounting metal conductor film 30 without filling with underfill, by arranging a side metal conductor film 18 on the side surface 152 of the cap layer 15 that constitutes the MEMS body 1 (see Figure 1).

[0047] (3-1) Basic Configuration of MEMS Device As shown in FIG. 2A, the MEMS device 100 includes a control IC 10, mounting pads 101, bumps 20, and a MEMS body 1.

[0048] (3-1-1) Control IC The control IC 10 is an IC (Integrated Circuit) that performs control using an electrical signal from the MEMS body 1. The control IC 10 may, for example, use an acceleration signal from the MEMS body 1 to perform motion detection of an appliance in which the MEMS device 100 is mounted.

[0049] (3-1-2) Mounting Pads and Bumps The mounting pads 101 are arranged on the control IC 10. In this example, the mounting pads 101 are arranged on the main surface of the control IC 10 (the upper surface in FIG. 2A).

[0050] The bumps 20 are disposed on the mounting pads 101. The bumps 20 are disposed on one of a pair of surfaces of the mounting pads 101, the surface opposite the control IC 10 (the upper surface in FIG. 2A ). The bumps 20 are specifically made of solder.

[0051] (3-1-3) MEMS Body The MEMS body 1 is mounted on the control IC 10 via the mounting pads 101 and bumps 20. The MEMS body 1 in this specific example is the MEMS device 100 described in "(1) Overview" and "(2) Details."

[0052] That is, as shown in FIG. 1, the MEMS body 1 includes a base layer 11, a semiconductor oxide layer 12, a device layer 13, a bonding layer 14, a cap layer 15, a movable portion 13A, a protective layer 16, an electrode pad 17, and a side metal conductor film 18.

[0053] (3-2) Detailed Configuration of the MEMS Device In the stacking direction, the base layer 11 has a wide portion 11a and a narrow portion 11b, with a boundary portion 11A as the boundary, as shown in Fig. 1. The width of the wide portion 11a in a direction Dr perpendicular to the stacking direction Ds is wider than the width of the narrow portion 11b in the direction Dr. Note that the boundary portion 11A in this specific example is a convenient element for dividing the base layer 11, which is an integrally molded single layer, into the wide portion 11a and the narrow portion 11b.

[0054] As shown in FIGS. 1 and 2A, the semiconductor oxide layer 12 is disposed in the narrow portion 11b of the base layer 11, and is not disposed in the wide portion 11a in this embodiment.

[0055] The side surface metal conductor film 18 in this example is disposed on the side surface 111b of the narrow width portion 11b of the base layer 11, the side surface 121 of the semiconductor oxide layer 12, the side surface 131 of the device layer 13, the side surface 141 of the bonding layer 14, the side surface 152 of the cap layer 15, and the side surface 162 of the protective layer 16. An end portion 181 of the side surface metal conductor film 18 is located on the step surface 111a of the boundary portion 11A, as shown in FIG.

[0056] This configuration makes it easy to increase the thickness of the mounting metal conductor film 30 for mounting the MEMS body 1 on the control IC 10 (for example, increase the amount of solder fillet), thereby improving the connection strength.

[0057] (3-3) Bump Arrangement The bump 20 is arranged between the mounting pad 101 and the electrode pad 17, as shown in FIG. 2A.

[0058] (3-4) Connection Electrodes and Mounting Metal Conductor Film As shown in FIG. 2A, the MEMS device 100 further includes connection electrodes 102 and a mounting metal conductor film 30.

[0059] The connection electrodes 102 are disposed on the control IC 10. As shown in Fig. 2A , the connection electrodes 102 in this specific example are disposed on the main surface of the control IC 10 at positions corresponding to the step surface 111a (see Fig. 1 ) of the base layer 11 on the MEMS body 1 side (below the step surface 111a).

[0060] 2A and 2B , the mounting metal conductor film 30 is connected to the side surface metal conductor film 18 and the connection electrode 102 so as to cover the periphery of the bump 20 sandwiched between the mounting pad 101 and the electrode pad 17 between the cap layer 15 or the protective layer 16 and the control IC 10. Specifically, the mounting metal conductor film 30 is a solder fillet.

[0061] (3-5) Advantages of the MEMS Device The MEMS device 100 of this example can improve the connection strength between the MEMS body 1 and the control IC 10 without filling with underfill. In addition, it avoids the deterioration of temperature characteristics caused by differences in thermal expansion coefficients that occurs when filling with underfill.

[0062] That is, in the MEMS device 100 of this example, the temperature characteristics of the MEMS body 1 can be maintained while improving the strength of the connection between the MEMS body 1 and the control IC 10 .

[0063] Furthermore, the gap between the MEMS main body 1 and the control IC 10, i.e., the space around the bumps 20, etc., is sealed and electromagnetically shielded by the mounting metal conductor film 30 (solder), thereby preventing the intrusion of gases such as moisture and oxidizing atmospheres, as well as electromagnetic noise.

[0064] (4) Modifications (4-1) Modifications of the Base Layer The base layer 11 may be a layer made of a semiconductor other than silicon. Examples of the semiconductor other than silicon include, but are not limited to, germanium (Ge) and selenium (Se).

[0065] In the embodiment, the base layer 11 is an integrally molded single layer, but it may have a two-layer structure in which a wide portion 11 a and a narrow portion 11 b are molded separately and joined at a boundary portion 11A (see FIG. 2A ). In other words, in this modification, the boundary portion 11A may be the joining surface between the wide portion 11 a and the narrow portion 11 b.

[0066] (4-2) Modified Examples of Semiconductor Oxide Layer The semiconductor oxide layer 12 may be a thin film of a semiconductor oxide other than silicon dioxide. Examples of semiconductor oxide other than silicon dioxide include zinc oxide (ZnO), nickel oxide (NiO), and tin oxide (SnO ２ ) but is not limited to these.

[0067] In the embodiment, the central portion of the semiconductor oxide layer 12 corresponding to the movable portion 13A (see FIG. 1) is removed, but a part of the central portion may remain without being removed. In other words, the semiconductor oxide layer 12 may also be interposed between the base layer 11 and the movable portion 13A.

[0068] (4-3) Modified Examples of Device Layer The device layer 13 may be a layer made of a semiconductor other than silicon.

[0069] (4-4) Modifications of the Cap Layer The cap layer 15 may be a layer made of a semiconductor other than silicon. Furthermore, the cap layer 15 is not limited to a layer made of a semiconductor, and may be a layer made of, for example, an insulator or a conductor.

[0070] In the embodiment, the cap layer 15 is laminated on the device layer 13 via the bonding layer 14, but may be laminated directly on the device layer 13. In other words, the semiconductors constituting the cap layer 15 and the device layer 13 may be directly bonded to each other.

[0071] (4-5) Modified Examples of Movable Part The movable part 13A is not limited to a movable electrode, but may be, for example, a movable magnet that displaces in response to the magnetic field around the MEMS device 100. Furthermore, the movable part 13A is not limited to a member (sensing element) that passively moves in response to the acceleration / deceleration of the MEMS device 100 or the magnetic field, but may be a member such as a micromachine that actively moves.

[0072] (4-6) Modifications of the Protective Layer The protective layer 16 may be a film other than a silicon nitride film, for example, a silicon oxide film.

[0073] (4-7) First Modification of Side Surface Metal Conductor Film The side surface metal conductor film 18 may cover only a portion of the side surface 152 of the cap layer 15. Even if only a portion of the side surface 152 of the cap layer 15 is covered with the side surface metal conductor film 18, the side surface 152 of the cap layer 15 and the control IC of the MEMS device can be connected (soldered) by the mounting metal conductor film 30, and therefore, the bonding strength can be improved without underfill (without deteriorating the temperature characteristics).

[0074] (4-8) Second Modification of Side Surface Metal Conductor Film The side surface metal conductor film 18 may cover only a part of the side surface of the semiconductor oxide layer 12. Even if only a part of the side surface 121 of the semiconductor oxide layer 12 is covered with the side surface metal conductor film 18, the effect of suppressing the intrusion of the atmosphere into the internal space SP1 via the semiconductor oxide layer 12 can be obtained.

[0075] (4-9) Third modified example of side surface metal conductor film In this modified example, as shown in FIG. 3, the side surface metal conductor film 18 is formed in an L-shape by the end 181 extending along the step surface 111a toward the side surface 11a1 of the wide portion 11a, i.e., extending toward the side surface 11a1.

[0076] According to this modification, the side metal conductor film 18 is L-shaped, and the mounting metal conductor film 30 (e.g., solder fillet) has a wider, flared shape as shown in Figure 4, thereby improving the connection strength.

[0077] (4-10) Fourth Modification of Side Surface Metal Conductor Film In this modification, the side surface metal conductor film 18 in the embodiment is a side surface first metal conductor film 18. The side surface first metal conductor film 18 is covered with a side surface second metal conductor film 19, as shown in FIG.

[0078] The second metal conductor film for side surface 19 is, for example, a nickel (Ni) film, and is realized by, for example, zincating nickel (Ni plating) the first metal conductor film for side surface 18, which is an aluminum film formed by vapor deposition.

[0079] However, the material of the second metal conductor film 19 for the side surface is not limited to nickel, and may be chromium (Cr) or the like. The second metal conductor film 19 for the side surface may be formed by a process other than the zincate process, for example, vapor deposition.

[0080] (5) Summary The MEMS device (100) according to the first aspect of the present disclosure comprises a base layer (11) made of a semiconductor, a semiconductor oxide layer (12) made of a semiconductor oxide film disposed on a main surface (111) of the base layer (11), a device layer (13) made of a semiconductor connected to the base layer (11) via the semiconductor oxide layer (12), a cap layer (15) connected to the device layer (13), a movable part (13A) disposed in an internal space (SP1) surrounded by the base layer (11), the semiconductor oxide layer (12), the device layer (13), and the cap layer (15), a protective layer (16) disposed on a main surface (151) of the cap layer (15), an electrode pad (17) disposed on the main surface (151) of the cap layer (15) or on a surface (161) of the protective layer (16) so as to output an electrical signal based on the movement of the movable part (13A), and a side metal conductor film (18) disposed on a side surface (152) of the cap layer (15).

[0081] According to this aspect, by disposing the side metal conductor film (18) on the side surface (152) of the cap layer (15), it is possible to improve the connection strength between the MEMS body (1) and the control IC (10) without filling with underfill.

[0082] In detail, the configuration of the first aspect is a configuration of a MEMS body (1), and the MEMS device (100) further comprises, in addition to the MEMS body (1), a control IC (10), a mounting pad (101) arranged on the control IC (10), a connection electrode (102) arranged on the control IC (10), and a bump (20) arranged between the mounting pad (101) and the electrode pad (17), and the MEMS body (1) is connected to the control IC (10) via the mounting pad ( In a configuration in which the MEMS body (1) is mounted via the electrode pads (17) and bumps (20), a mounting metal conductor film (30) is further provided that connects the side metal conductor film (18) and the connection electrodes (102) so as to cover the periphery of the bumps (20) sandwiched between the electrode pads (17) and the mounting pads (101) between the cap layer (15) or the protective layer (16) and the control IC (10), thereby improving the connection strength between the MEMS body (1) and the control IC (10).

[0083] Furthermore, it is possible to avoid a deterioration in temperature characteristics due to differences in thermal expansion coefficients, which occurs when underfilling is performed, and thus it is possible to improve the connection strength between the MEMS body (1) and the control IC (10) while maintaining the temperature characteristics of the MEMS body (1).

[0084] Furthermore, the gap between the MEMS body (1) and the control IC (10), i.e., the space around the bump (20), is sealed and electromagnetically shielded by the mounting metal conductor film (30), thereby preventing the intrusion of moisture, gases such as oxidizing atmospheres, and electromagnetic noise.

[0085] In the MEMS device (100) according to the second aspect, in the first aspect, the side surface metal conductor film (18) is arranged so as to cover the entire periphery of the side surface (152) of the cap layer (15).

[0086] According to this embodiment, the entire periphery of the side surface (152) of the cap layer (15) is covered with the side surface metal conductor film (18), thereby further improving the connection strength.

[0087] The MEMS device (100) according to the third aspect is the MEMS device (100) according to the first or second aspect, further comprising a bonding layer (14) disposed between the device layer (13) and the cap layer (15). The cap layer (15) is connected to the device layer (13) via the bonding layer (14).

[0088] According to this embodiment, it is possible to improve the bonding strength of the cap layer (15) to the device layer (13). In addition, by interposing the bonding layer (14) between the cap layer (15) and the device layer (13), it is possible to expand the internal space (SP1).

[0089] In the MEMS device (100) according to the fourth aspect, in any one of the first to third aspects, the side metal conductor film (18) is further connected to the base layer (11) and the device layer (13).

[0090] According to this aspect, the base layer (11) and the device layer (13) are at the same potential, thereby improving the accuracy of the electrical signal from the MEMS device (100).

[0091] In the MEMS device (100) according to the fifth aspect, in any one of the first to fourth aspects, the side metal conductor film (18) is further disposed on the side surface (121) of the semiconductor oxide layer (12).

[0092] According to this aspect, by disposing the side metal conductor film (18) also on the side surface (121) of the semiconductor oxide layer (12), it is possible to improve the connection strength while preventing the external atmosphere from entering the semiconductor oxide layer (12).

[0093] In the MEMS device (100) according to the sixth aspect, in the fifth aspect, the side surface metal conductor film (18) is arranged so as to cover the entire periphery of the side surface (121) of the semiconductor oxide layer (12).

[0094] According to this aspect, by covering the entire periphery of the side surface (121) of the semiconductor oxide layer (12) with the side surface metal conductor film (18), it is possible to improve the connection strength while preventing the external atmosphere from entering the semiconductor oxide layer (12).

[0095] In the MEMS device (100) according to the seventh aspect, in any of the first to sixth aspects, the base layer (11) has a wide portion (11a) and a narrow portion (11b) in the stacking direction, with a boundary portion (11A) as the boundary, the semiconductor oxide layer (12) is disposed in the narrow portion (11b), and the end portion (181) of the side metal conductor film (18) is located on the step surface (111a) of the boundary portion (11A).

[0096] According to this aspect, it becomes easy to increase the thickness (for example, increase the amount of solder fillet) of the metal conductor film for another side surface (metal conductor film for mounting 30) for connecting the control IC (10) to the MEMS body (1), thereby improving the connection strength.

[0097] In the MEMS device (100) according to the eighth aspect, in the seventh aspect, the side metal conductor film (18) is formed in an L-shape by having the end (181) extend along the step surface (111a).

[0098] According to this embodiment, the side metal conductor film (18) is L-shaped, and the mounting metal conductor film (30) has a wider, flared shape, for example, thereby improving the connection strength.

[0099] The MEMS device (100) according to the ninth aspect comprises a control IC (10), a mounting pad (101) arranged on the control IC (10), a bump (20) arranged on the mounting pad (101), and a MEMS body (1) mounted on the control IC (10) via the mounting pad (101) and the bump (20). The MEMS body (1) comprises: a base layer (11) made of a semiconductor; a semiconductor oxide layer (12) made of a semiconductor oxide film disposed on a main surface (111) of the base layer (11); a device layer (13) made of a semiconductor connected to the base layer (11) via the semiconductor oxide layer (12); a cap layer (15) connected to the device layer (13); a movable part (13A) disposed in an internal space (SP1) surrounded by the base layer (11), the semiconductor oxide layer (12), the device layer (13), and the cap layer (15); a protective layer (16) disposed on a main surface (151) of the cap layer (15); an electrode pad (17) disposed on the main surface (151) of the cap layer (15) or on a surface (161) of the protective layer (16) so as to output an electrical signal based on the movement of the movable part (13A); and a side metal conductor film (18) disposed on a side surface (152) of the cap layer (15). The bump (20) is disposed between the mounting pad (101) and the electrode pad (17). The MEMS device (100) further includes a connection electrode (102) disposed on the control IC (10), and a mounting metal conductor film (30) connected to the side metal conductor film (18) and the connection electrode (102) so as to cover the periphery of the bump (20) sandwiched between the mounting pad (101) and the electrode pad (17) between the cap layer (15) or the protective layer (16) and the control IC (10).

[0100] According to this embodiment, the connection strength between the MEMS body (1) and the control IC (10) can be improved without filling with underfill. Also, it is possible to avoid the deterioration of temperature characteristics caused by differences in thermal expansion coefficients, which occurs when filling with underfill. In other words, it is possible to improve the connection strength between the MEMS body (1) and the control IC (10) while maintaining the temperature characteristics of the MEMS body (1).

[0101] Furthermore, the gap between the MEMS body (1) and the control IC (10), i.e., the space around the bump (20), is sealed and electromagnetically shielded by the mounting metal conductor film (30), thereby preventing the intrusion of moisture, gases such as oxidizing atmospheres, and electromagnetic noise.

[0102] In the MEMS device (100) according to the tenth aspect, in the ninth aspect, the side surface metal conductor film (18) is arranged so as to cover the entire periphery of the side surface (152) of the cap layer (15).

[0103] According to this embodiment, the entire periphery of the side surface (152) of the cap layer (15) is covered with the side surface metal conductor film (18), thereby further improving the connection strength.

[0104] The MEMS device (100) according to an eleventh aspect is the MEMS device (100) of the ninth or tenth aspect, further comprising a bonding layer (14) disposed between the device layer (13) and the cap layer (15). The cap layer (15) is connected to the device layer (13) via the bonding layer (14).

[0105] According to this embodiment, it is possible to improve the bonding strength of the cap layer (15) to the device layer (13). In addition, by interposing the bonding layer (14) between the cap layer (15) and the device layer (13), it is possible to expand the internal space (SP1).

[0106] In the MEMS device (100) according to the twelfth aspect, in any one of the ninth to eleventh aspects, the side metal conductor film (18) is further connected to the base layer (11) and the device layer (13).

[0107] According to this aspect, the base layer (11) and the device layer (13) are at the same potential, thereby improving the accuracy of the electrical signal from the MEMS device (100).

[0108] In the MEMS device (100) according to the thirteenth aspect, in any one of the ninth to twelfth aspects, the side metal conductor film (18) is further disposed on the side surface (121) of the semiconductor oxide layer (12).

[0109] According to this aspect, by disposing the side metal conductor film (18) also on the side surface (121) of the semiconductor oxide layer (12), it is possible to improve the connection strength while preventing the external atmosphere from entering the semiconductor oxide layer (12).

[0110] In the MEMS device (100) according to the fourteenth aspect, in the thirteenth aspect, the side surface metal conductor film (18) is arranged so as to cover the entire periphery of the side surface (121) of the semiconductor oxide layer (12).

[0111] According to this aspect, by covering the entire periphery of the side surface (121) of the semiconductor oxide layer (12) with the side surface metal conductor film (18), it is possible to improve the connection strength while preventing the external atmosphere from entering the semiconductor oxide layer (12).

[0112] In the MEMS device (100) according to the fifteenth aspect, in any of the ninth to fourteenth aspects, the base layer (11) has a wide portion (11a) and a narrow portion (11b) in the stacking direction, with a boundary portion (11A) as the boundary, the semiconductor oxide layer (12) is disposed in the narrow portion (11b), and the end portion (181) of the side metal conductor film (18) is located on the step surface (111a) of the boundary portion (11A).

[0113] According to this aspect, it becomes easy to increase the thickness (for example, increase the amount of solder fillet) of the metal conductor film for another side surface (metal conductor film for mounting 30) for connecting the control IC (10) to the MEMS body (1), thereby improving the connection strength.

[0114] In the MEMS device (100) according to the sixteenth aspect, in the fifteenth aspect, the side metal conductor film (18) is formed in an L-shape by having the end (181) extend along the step surface (111a).

[0115] According to this embodiment, the side metal conductor film (18) is L-shaped and the mounting metal conductor film (30) is wider and flared at the bottom, thereby improving the connection strength.

[0116] 100 MEMS device 10 Control IC 101 Mounting pad 102 Connection electrode 1 MEMS body 11 Base layer 111 Main surface 111a Step surface 11A Boundary portion 11a Wide portion 11b Narrow portion 12 Semiconductor oxide layer 121 Side surface 13 Device layer 13A Movable portion 14 Bonding layer 15 Cap layer 151 Main surface 152 Side surface 16 Protective layer 161 Surface SP1 Internal space 17 Electrode pad 18 Side surface metal conductor film (side surface first metal conductor film) 181 End portion 19 Side surface second metal conductor film 20 Bump 30 Mounting metal conductor film

Claims

1. A MEMS (Micro Electro Mechanical Systems) device comprising: a base layer made of a semiconductor; a semiconductor oxide layer made of a semiconductor oxide film arranged on a main surface of the base layer; a device layer made of a semiconductor connected to the base layer via the semiconductor oxide layer; a cap layer connected to the device layer; a movable part arranged in an internal space surrounded by the base layer, the semiconductor oxide layer, the device layer, and the cap layer; a protective layer arranged on the main surface of the cap layer; electrode pads arranged on the main surface of the cap layer or on the surface of the protective layer so as to output an electrical signal based on movement of the movable part; and a side metal conductor film arranged on a side surface of the cap layer.

2. The MEMS device according to claim 1, wherein the side surface metal conductor film is disposed so as to cover the entire periphery of the side surface of the cap layer.

3. The MEMS device according to claim 1, further comprising a bonding layer disposed between the device layer and the cap layer, the cap layer being connected to the device layer via the bonding layer.

4. The MEMS device according to claim 1, wherein the side metal conductor film is further connected to the base layer and the device layer.

5. The MEMS device according to any one of claims 1 to 4, wherein the side surface metal conductor film is further disposed on a side surface of the semiconductor oxide layer.

6. The MEMS device according to claim 5, wherein the side surface metal conductor film is disposed so as to cover the entire periphery of the side surface of the semiconductor oxide layer.

7. The MEMS device according to claim 1, wherein the base layer has a wide portion and a narrow portion separated by a boundary portion in the stacking direction, the semiconductor oxide layer is disposed in the narrow portion, and an end portion of the side metal conductor film is located on a step surface of the boundary portion.

8. The MEMS device according to claim 7, wherein the side surface metal conductor film is formed in an L-shape with the end portion extending along the step surface.

9. A device comprising a control IC, a mounting pad disposed on the control IC, a bump disposed on the mounting pad, and a MEMS (Micro Electro Mechanical Systems) body mounted on the control IC via the mounting pad and the bump, wherein the MEMS body comprises: a base layer made of a semiconductor, a semiconductor oxide layer made of a semiconductor oxide film disposed on a main surface of the base layer, a device layer made of a semiconductor connected to the base layer via the semiconductor oxide layer, a cap layer connected to the device layer, a movable part disposed in an internal space surrounded by the base layer, the semiconductor oxide layer, the device layer, and the cap layer, a protective layer disposed on the main surface of the cap layer, an electrode pad disposed on the main surface of the cap layer or on the surface of the protective layer so as to output an electrical signal based on the movement of the movable part, and a side metal conductor film disposed on a side surface of the cap layer, wherein the bump is disposed between the mounting pad and the electrode pad, and a connection electrode disposed on the control IC, a mounting metal conductor film connected to the side surface metal conductor film and the connection electrode so as to cover the periphery of the bump sandwiched between the mounting pad and the electrode pad between the cap layer or the protective layer and the control IC.

10. The MEMS device according to claim 9, wherein the side surface metal conductor film is disposed so as to cover the entire periphery of the side surface of the cap layer.

11. The MEMS device according to claim 9, further comprising a bonding layer disposed between the device layer and the cap layer, the cap layer being connected to the device layer via the bonding layer.

12. The MEMS device according to claim 9, wherein the side metal conductor film is further connected to the base layer and the device layer.

13. The MEMS device according to claim 9, wherein the side surface metal conductor film is further disposed on a side surface of the semiconductor oxide layer.

14. The MEMS device according to claim 13, wherein the side surface metal conductor film is disposed so as to cover the entire periphery of the side surface of the semiconductor oxide layer.

15. A MEMS device as described in claim 9, wherein the base layer has a wide portion and a narrow portion separated by a boundary portion in the stacking direction, the semiconductor oxide layer is disposed in the narrow portion, and an end portion of the side metal conductor film is located on a step surface of the boundary portion.

16. The MEMS device according to claim 15, wherein the side surface metal conductor film is formed in an L-shape with the end portion extending along the step surface.

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