Vibration device and method for manufacturing the same

Abstract

A vibration device and a method for manufacturing a vibration device can suppress poor wiring patterning. The vibration device comprises: a base; and a vibration element arranged on the base. The base comprises: a semiconductor substrate having a first surface and a second surface that are in a front-to-back relationship with each other; an integrated circuit comprising a wiring layer and an insulating layer, the wiring layer being arranged on the second surface side and having a connection pad, the insulating layer being arranged between the second surface and the wiring layer; a through electrode that penetrates the semiconductor substrate and the insulating layer and is connected to the connection pad; and an annular metal layer that penetrates the insulating layer and is arranged between the second surface and the wiring layer, and surrounds the through electrode when the semiconductor substrate is viewed from above.

Description

Technical Field

[0001] The present invention relates to a vibration device and a method for manufacturing the vibration device. Background Art

[0002] The semiconductor substrate described in Patent Document 1 includes a silicon substrate, an insulating layer formed on the silicon substrate, a conductive pad formed on the insulating layer, and a through-electrode that penetrates the silicon substrate and the insulating layer and is connected to the conductive pad. Furthermore, the through-electrode forming method includes forming a through-hole in the silicon substrate using dry etching, forming a through-hole in the insulating layer using wet etching, and filling the through-hole with a metal material.

[0003] Patent Document 1: Japanese Patent Application No. 2014-519201

[0004] Thus, in the through-electrode formation method of Patent Document 1, wet etching is used to form through-holes in the insulating layer. However, wet etching is isotropic. Therefore, side etching occurs in the insulating layer, and metal material intrudes into the gaps unintentionally created by the side etching, resulting in poor wiring patterning (hereinafter also referred to as "poor wiring patterning caused by side etching"). Summary of the Invention

[0005] The vibration device of the present invention comprises: a base; and a vibration element arranged on the base, the base comprising: a semiconductor substrate having a first surface and a second surface in a front-to-back relationship with each other; an integrated circuit comprising a wiring layer and an insulating layer, the wiring layer being arranged on the second surface side and having a connection pad, the insulating layer being arranged between the second surface and the wiring layer; a through electrode penetrating the semiconductor substrate and the insulating layer and connected to the connection pad; an annular metal layer penetrating the insulating layer and being arranged between the second surface and the wiring layer, surrounding the through electrode when looking down at the semiconductor substrate.

[0006] The manufacturing method of the vibration device of the present invention includes: a base preparation process, preparing a base, the base having: a semiconductor substrate, which has a first surface and a second surface in a positive and negative relationship with each other; an integrated circuit, which includes a wiring layer and an insulating layer, the wiring layer is arranged on the second surface side and has a connection pad, the insulating layer is arranged between the second surface and the wiring layer; an annular metal layer, which passes through the insulating layer and is arranged between the second surface and the wiring layer; and a through-electrode forming process, forming a through-electrode, which passes through the semiconductor substrate and the insulating layer, passes through the inner side of the metal layer and is connected to the connection pad, the through-electrode forming process includes: a through-hole forming process, after using dry etching to penetrate the semiconductor substrate, using wet etching to penetrate the insulating layer, thereby forming a through-hole that passes from the first surface through the inner side of the metal layer and is opposite to the connection pad; and a conductive material configuration process, configuring a conductive material in the through-hole to form the through-electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a longitudinal sectional view showing the vibration device according to the first embodiment.

[0008] Figure 2 It is a plan view showing the upper surface of the base.

[0009] Figure 3 It is a longitudinal sectional view showing a metal layer surrounding the through-electrode.

[0010] Figure 4 is a cross-sectional view showing a metal layer surrounding a through-electrode.

[0011] Figure 5 is a top view showing the vibration element.

[0012] Figure 6 This is a flowchart showing the manufacturing process of the vibration device.

[0013] Figure 7 It is a longitudinal sectional view for explaining the manufacturing method of the vibration device.

[0014] Figure 8 It is a longitudinal sectional view for explaining the manufacturing method of the vibration device.

[0015] Figure 9 It is a longitudinal sectional view for explaining the manufacturing method of the vibration device.

[0016] Figure 10 It is a longitudinal sectional view for explaining the manufacturing method of the vibration device.

[0017] Figure 11 It is a longitudinal sectional view for explaining the manufacturing method of the vibration device.

[0018] Figure 12 It is a longitudinal sectional view for explaining the manufacturing method of the vibration device.

[0019] Figure 13 It is a longitudinal sectional view for explaining the manufacturing method of the vibration device.

[0020] Figure 14 It is a longitudinal sectional view for explaining the manufacturing method of the vibration device.

[0021] Figure 15 It is a longitudinal sectional view showing a vibration device according to a second embodiment.

[0022] Figure 16 It is a cross-sectional view showing a metal layer included in the vibration device according to the third embodiment.

[0023] Description of labels

[0024] 1. Vibration device; 10. Package; 2. Base; 2. Through hole; 2.10. Through electrode; 2.11. Through hole; 2.12. Through hole; 2.13. Through hole; 2.2. Through hole; 2.2. Through electrode; 2.2. Through hole; 2.2. Through hole; 2.3. Through hole; 2.3. Through electrode; 2.6. Mounting terminal; 2.8. Wiring; 2.9. Wiring; 3. Cover; 3.1. Recess; 4. Vibration element; 4.1. Vibration substrate; 4.2. Electrode; 4.2. Excitation electrode; 4.2. Excitation electrode; 4.2. Terminal; 4.2.4 Terminal; 4.2.5. Wiring; 4.2.6. Wiring; 5. Semiconductor substrate; 5.a. First surface; 5.b. Second surface; 5.0. Insulation film; 6. Integrated circuit; 6.a. Oscillation circuit; 6.0. Laminated body; 6.1. Etching stop layer; 6.2. Insulation layer; 6.3. Wiring layer; 631 connecting pad; 632 connecting pad; 64 insulating layer; 65 wiring layer; 66 insulating layer; 67 passivation film; 68 terminal layer; 681 mounting terminal; 682 wiring; 683 wiring; 7 joining component; 81 metal bump; 82 metal bump; 691 metal layer; 691a first metal layer; 691b second metal layer; 691c third metal layer; 692 metal layer; 692a first metal layer; 692b second metal layer; 692c third metal layer; 693 metal layer; E conductive material; S storage portion; S1 base preparation process; S2 through-electrode forming process; S21 through-hole forming process; S22 conductive material configuration process; S3 vibration element configuration process; S4 cover configuration process. DETAILED DESCRIPTION

[0025] Hereinafter, the preferred embodiment of the vibration device will be described with reference to the accompanying drawings. Figure 1 、 Figure 3 、 Figures 7 to 15 The upper side of the paper is also referred to as "upper", and the lower side of the paper is also referred to as "lower".

[0026] <First embodiment>

[0027] Figure 1 It is a longitudinal sectional view showing the vibration device according to the first embodiment. Figure 2 It is a plan view showing the upper surface of the base. Figure 3 It is a longitudinal sectional view showing a metal layer surrounding the through-electrode. Figure 4 is a cross-sectional view showing a metal layer surrounding a through-electrode. Figure 5 is a top view showing the vibration element. Figure 6 This is a flowchart showing the manufacturing process of the vibration device. Figures 7 to 14 This is a longitudinal sectional view for explaining a method for manufacturing a vibration device. Figure 1 yes Figure 2 AA line section view in.

[0028] like Figure 1 As shown, the vibration device 1 includes a package 10 having a housing portion S and a vibration element 4 housed in the housing portion S. The package 10 also includes a base 2 on which the vibration element 4 is mounted, and a cover 3 that covers the vibration element 4 and is bonded to the upper surface of the base 2. The base 2 also includes a semiconductor substrate 5 and an integrated circuit 6 disposed on the semiconductor substrate 5.

[0029] The semiconductor substrate 5 is a silicon substrate, particularly a P-type silicon substrate. However, the semiconductor substrate 5 is not particularly limited and may also be an N-type silicon substrate. Furthermore, the semiconductor substrate 5 may be a semiconductor substrate other than silicon, such as a semiconductor substrate made of Ge, GaP, GaAs, or InP.

[0030] The semiconductor substrate 5 is plate-shaped and has a first surface 5a and a second surface 5b that are located opposite each other. The first surface 5a is the top surface, and the second surface 5b is the bottom surface. Furthermore, an insulating film 50 composed of SiO2 (silicon oxide) is formed on the front surface of the semiconductor substrate 5. However, the insulating film 50 is not particularly limited and may be, for example, an organic insulating film.

[0031] Furthermore, an integrated circuit 6 electrically connected to the vibration element 4 is formed on the second surface 5b of the semiconductor substrate 5. Forming the integrated circuit 6 on the semiconductor substrate 5 allows for efficient use of the semiconductor substrate 5. In particular, by forming the integrated circuit 6 on the second surface 5b, there is no bonding area with the lid 3, compared to when the integrated circuit 6 is formed on the first surface 5a. Consequently, a correspondingly larger space can be secured for forming the integrated circuit 6.

[0032] Integrated circuit 6 includes an oscillation circuit 6A. Oscillation circuit 6A is electrically connected to vibration element 4 and causes vibration element 4 to oscillate, thereby generating an oscillation signal such as a clock signal. Integrated circuit 6 may further include circuits other than oscillation circuit 6A. Examples of such circuits include a processing circuit that processes the output signal from oscillation circuit 6A. Examples of such processing circuits include a PLL circuit.

[0033] On the second surface 5b side, a stacked body 60 is formed in which an etching stopper layer 61, an insulating layer 62, a wiring layer 63, an insulating layer 64, a wiring layer 65, an insulating layer 66, a passivation film 67, and a terminal layer 68 are stacked in this order. Furthermore, a plurality of active elements (not shown) formed on the second surface 5b are electrically connected by the wiring layers 63 and 65 to form an integrated circuit 6. Furthermore, the terminal layer 68 has a plurality of mounting terminals 681. The integrated circuit 6 is electrically connected to an external device via these mounting terminals 681. The number of wiring layers included in the stacked body 60 is not particularly limited and may be one or more than three.

[0034] In addition, a pair of through holes 21 and 22 are formed on the base 2 from its upper surface side, penetrating the semiconductor substrate 5, the etch stop layer 61, and the insulating layer 62 in the thickness direction and facing the wiring layer 63. As will be described in the manufacturing method of the vibration device 1 described later, the through holes 21 and 22 are formed by penetrating the semiconductor substrate 5 and the etch stop layer 61 using dry etching, and then penetrating the insulating layer 62 using wet etching. According to this formation method, since the through holes 21 and 22 reach the wiring layer 63 during wet etching, plasma damage to the wiring layer 63 can be suppressed. In addition, since the semiconductor substrate 5 is penetrated by dry etching, the through holes 21 and 22 with a large aspect ratio can be formed. Therefore, the reliability of the vibration device 1 can be improved while miniaturizing the vibration device 1.

[0035] Each through-hole 21 or 22 is filled with a conductive material E to form a through-electrode 210 or 220. The through-electrodes 210 or 220 are electrically connected to the lands 631 or 632 of the wiring layer 63, respectively. Specifically, the through-electrodes 210 or 220 are connected to the lands 631 or 632 of the wiring layer 63, whichever is closest to the semiconductor substrate 5, among the multiple wiring layers 63 or 65 included in the integrated circuit 6. This allows the through-electrodes 210 or 220 to be shorter than when connected to the lands of the wiring layer 65. This makes it easier to form the through-electrodes 210 or 220. However, this is not limiting; for example, the through-electrodes 210 or 220 may also be connected to the lands of the wiring layer 65.

[0036] In addition, if Figure 2As shown, a pair of wirings 28 and 29 electrically connected to the vibration element 4 via metal bumps 81 and 82 are arranged on the first surface 5a side of the semiconductor substrate 5. The wiring 28 is electrically connected to the integrated circuit 6 via a through electrode 210, and the wiring 29 is electrically connected to the integrated circuit 6 via a through electrode 220.

[0037] In addition, if Figure 1 and Figure 3 As shown in FIG. 1 , metal layers 691 and 692 are formed on the substrate 2 between the etching stopper layer 61 and the wiring layer 63 so as to penetrate the insulating layer 62. Figure 4 As shown, the metal layers 691 and 692 are ring-shaped, surrounding the through-electrodes 210 and 220, when viewed from above the semiconductor substrate 5. Connecting pads 631 and 632 connected to the through-electrodes 210 and 220 are provided on the wiring layer 63. When viewed from above the semiconductor substrate 5, the metal layer 691 is enclosed by the connecting pad 631, and the metal layer 692 is enclosed by the connecting pad 632. Therefore, the upper ends of the metal layers 691 and 692 pass through the insulating layer 62 and contact the lower surface of the etch stop layer 61, while the lower ends of the metal layers 691 and 692 pass through the insulating layer 62 and contact the upper surfaces of the connecting pads 631 and 632.

[0038] As will be described later in the method for manufacturing the resonator device 1, these metal layers 691 and 692 function as etch-stop layers, or guard rings, when forming the through-holes 21 and 22. The provision of these metal layers 691 and 692 limits side etching outward from the metal layers 691 and 692 when forming the through-holes 21 and 22 in the insulating layer 62 using wet etching, thereby suppressing further unintentional side etching. Consequently, wiring patterning defects caused by side etching can be suppressed, resulting in a highly reliable resonator device 1.

[0039] The cover 3 is a silicon substrate, similar to the semiconductor substrate 5. Therefore, the linear expansion coefficients of the semiconductor substrate 5 and the cover 3 are equal. Therefore, the vibration device 1 suppresses the generation of thermal stress caused by thermal expansion and has excellent vibration characteristics. In addition, the vibration device 1 can be formed by a semiconductor process, so the vibration device 1 can be manufactured with high precision and can be miniaturized. However, the cover 3 is not particularly limited, and semiconductor substrates other than silicon, such as semiconductor substrates of Ge, GaP, GaAs, InP, etc., can also be used. In addition, for example, substrates other than semiconductor substrates such as metal substrates of Kovar alloy and glass substrates can also be used.

[0040] like Figure 1As shown, the cover 3 has a bottomed recess 31 that is open on its lower surface and accommodates the vibration element 4 therein. Furthermore, the cover 3 is joined to the upper surface of the base 2 via a joining member 7 on its lower surface. Thus, a space for accommodating the vibration element 4, i.e., a receiving portion S, is formed between the cover 3 and the base 2. In this embodiment, diffusion bonding utilizing the diffusion of metals is used to join the cover 3 and the base 2. However, the method for joining the cover 3 and the base 2 is not particularly limited.

[0041] The storage section S is airtight and in a reduced pressure state, preferably a state closer to a vacuum. This reduces viscous resistance and improves the oscillation characteristics of the vibrating element 4. However, the atmosphere in the storage section S is not particularly limited; for example, it may be an atmosphere containing an inert gas such as nitrogen or Ar, or it may be in an atmospheric pressure or pressurized state rather than a reduced pressure state.

[0042] like Figure 5 As shown, the vibration element 4 has a vibration substrate 41 and an electrode 42 arranged on the front surface of the vibration substrate 41. The vibration substrate 41 has a thickness shear vibration mode and is formed of an AT-cut quartz substrate in this embodiment. The AT-cut quartz substrate has a third-order frequency-temperature characteristic, and therefore becomes a vibration element 4 with excellent temperature characteristics. In addition, the electrode 42 has an excitation electrode 421 arranged on the upper surface of the vibration substrate 41, and an excitation electrode 422 arranged on the lower surface opposite to the excitation electrode 421. In addition, the electrode 42 has: a pair of terminals 423 and 424 arranged on the lower surface of the vibration substrate 41; a wiring 425 electrically connecting the terminal 423 and the excitation electrode 421; and a wiring 426 electrically connecting the terminal 424 and the excitation electrode 422.

[0043] The structure of the vibration element 4 is not limited to the above-described structure. For example, the vibration element 4 may be a mesa-type structure in which the vibration region, sandwiched between the excitation electrodes 421 and 422, protrudes from its surroundings, or conversely, an inverted mesa-type structure in which the vibration region is recessed from its surroundings. Furthermore, the vibration substrate 41 may be subjected to bevel processing by grinding the periphery, or to crowning processing by making the upper and lower surfaces convex.

[0044] Furthermore, the vibration element 4 is not limited to vibrating in the thickness shear vibration mode. For example, it may also be formed by bending the multiple vibration arms in the in-plane direction, as in a tuning fork-type vibration element. That is, the vibration substrate 41 is not limited to being formed of an AT-cut quartz substrate. It may also be formed of a quartz substrate other than an AT-cut quartz substrate, such as an X-cut quartz substrate, a Y-cut quartz substrate, a Z-cut quartz substrate, a BT-cut quartz substrate, an SC-cut quartz substrate, or an ST-cut quartz substrate.

[0045] Furthermore, the material constituting the vibration substrate 41 is not limited to quartz; for example, it may be composed of piezoelectric single crystals such as lithium niobate, lithium tantalate, lithium tetraborate, lanthanum gallium silicate, potassium niobate, and gallium phosphate, or may be composed of piezoelectric single crystals other than these. Furthermore, the vibration element 4 is not limited to a piezoelectrically driven reed; it may also be an electrostatically driven reed that utilizes electrostatic force.

[0046] The vibration element 4 is located on the first surface 5a side of the semiconductor substrate 5. Furthermore, the vibration element 4 is bonded to the base 2 via a pair of metal bumps 81 and 82 and electrically connected to the wirings 28 and 29. The metal bumps 81 and 82 may be stud bumps, plated bumps, or the like. The method for connecting the vibration element 4 to the base 2 is not particularly limited. For example, the vibration element 4 may be bonded to the base 2 using a conductive adhesive and electrically connected to the wirings 28 and 29.

[0047] The structure of the vibration device 1 has been described above. Next, a method for manufacturing the vibration device 1 will be described. Figure 6 As shown, the manufacturing method of the vibration device 1 includes a base preparation step S1, a through-electrode forming step S2, a vibration element placement step S3, and a lid placement step S4. The through-electrode forming step S2 includes a through-hole forming step S21 and a conductive material placement step S22.

[0048] <Base preparation step S1>

[0049] First, if Figure 7 As shown, the base 2 is prepared. At this stage, the through electrodes 210, 220 and the wirings 28, 29 are not formed on the base 2. That is, the base 2 has a semiconductor substrate 5, an integrated circuit 6 arranged on the second surface 5b side of the semiconductor substrate 5, and annular metal layers 691, 692 formed in the integrated circuit 6. The etching stop layer 61 is composed of SiN (silicon nitride), and the insulating layers 62, 64 are composed of SiO2 (silicon oxide). In addition, the wiring layers 63, 65, the terminal layer 68 and the metal layers 691, 692 are respectively composed of aluminum (Al), and the passivation film 67 is composed of polyimide. However, the constituent materials of these layers are not particularly limited as long as they can perform their functions.

[0050] <Through Electrode Forming Step S2>

[0051] <<Through-hole forming step S21>>

[0052] Then, if Figure 8As shown, through holes 211 and 221 are formed that penetrate the semiconductor substrate 5 in the thickness direction. The through holes 211 and 221 are formed by dry etching, in particular the Bosch method. Thus, through holes 211 and 221 with a high aspect ratio can be formed. In addition, the etching stop layer 61 functions as a stop layer for the dry etching. In particular, the etching stop layer 61 is made of SiN (silicon nitride), and thus the etching stop layer 61 has a high selectivity for the dry etching and can effectively suppress over-etching. Therefore, for example, it is possible to effectively suppress the through holes 211 and 221 from reaching the wiring layer 63 and causing plasma damage to the wiring layer 63. As a result, it is possible to manufacture a vibration device 1 with high reliability that suppresses poor wiring patterning caused by the dry etching.

[0053] Then, if Figure 9 As shown, through holes 212 and 222 are formed by digging from the bottom ends of through holes 211 and 221 to penetrate the etch stop layer 61 in the thickness direction. Through holes 212 and 222 are formed by dry etching. However, this is not limiting and through holes 212 and 222 may also be formed by wet etching.

[0054] Then, if Figure 10 As shown, through holes 213 and 223 are formed by digging from the lower ends of through holes 212 and 222, passing through the inner sides of metal layers 691 and 692 and penetrating the insulating layer 62 in the thickness direction. Through holes 213 and 223 are formed by wet etching. By forming through holes 213 and 223 by wet etching, plasma damage to the wiring layer 63, as is the case when forming by dry etching, is not caused. Therefore, poor wiring patterning due to dry etching can be suppressed. Instead, side etching may occur in wet etching, resulting in poor wiring patterning due to wet etching. However, in this embodiment, through holes 213 and 223 pass through the inner sides of metal layers 691 and 692, so further side etching toward the outside is restricted by metal layers 691 and 692. Therefore, unintended side etching can be suppressed. As a result, a vibration device 1 with high reliability can be manufactured in which poor wiring patterning due to side etching is suppressed.

[0055] In particular, in this embodiment, when looking down at the semiconductor substrate 5, the metal layers 691 and 692 are contained within the lands 631 and 632, and the lower ends of the metal layers 691 and 692 are in contact with the upper surfaces of the lands 631 and 632. This effectively prevents the etching solution from invading the outside of the metal layers 691 and 692, effectively suppressing undesirable side etching. Consequently, patterning defects in the wiring caused by wet etching can be more effectively suppressed.

[0056] Through the above steps, through-holes 21 and 22 are formed, extending from the first surface 5a through the inner sides of the metal layers 691 and 692 and facing the lands 631 and 632 of the wiring layer 63. This method for forming through-holes 21 and 22 suppresses plasma damage to the wiring layer 63 and patterning defects in the wiring caused by side etching, thereby forming through-holes 21 and 22 with a high aspect ratio. Consequently, a highly reliable and compact resonator device 1 can be manufactured.

[0057] <<Conductive Material Arrangement Step S22>>

[0058] Then, if Figure 11 As shown in FIG. 1 , an insulating film 50 is formed on the first surface 5a of the semiconductor substrate 5 and the inner surfaces of the through holes 21 and 22. The method for forming the insulating film 50 is not particularly limited, and for example, CVD (chemical vapor deposition) can be used. Figure 12 As shown, the insulating film 50 formed on the bottom surfaces of the through holes 21 and 22 is removed by etching, so that the connection lands 631 and 632 are exposed in the through holes 21 and 22 .

[0059] Next, the conductive material E is arranged in a film shape on the first surface 5a and filled into the through holes 21 and 22. Next, the conductive material E on the first surface 5a is patterned by etching. Figure 13 As shown, the wirings 28 and 29 and the through electrodes 210 and 220 are formed together. In addition, the conductive material E is not particularly limited, and for example, the same material as the wiring layer 63 can be used. As a result, the affinity between the through electrodes 210 and 220 and the wiring layer 63 is improved, and poor contact between them can be effectively suppressed. In addition, since the materials can be shared, the manufacturing cost of the vibration device 1 can also be reduced. Among them, the conductive material E is not particularly limited, and for example, it can also be a stacked structure of titanium tungsten alloy (TiW) / copper (Cu) / gold (Au).

[0060] <<Vibration Element Arrangement Step S3>>

[0061] Next, the vibration element 4 is mounted on the wirings 28 and 29 via the metal bumps 81 and 82 .

[0062] <<Lid Arrangement Step S4>>

[0063] Next, the cover 3 is joined to the upper surface of the base 2. Figure 14 As shown, the vibration device 1 is manufactured.

[0064] The above describes in detail the vibration device 1 and the method for manufacturing the vibration device 1. As described above, the vibration device 1 includes a base 2 and a vibration element 4 arranged on the base 2. Furthermore, the base 2 includes: a semiconductor substrate 5 having a first surface 5a and a second surface 5b that are disposed opposite each other; an integrated circuit 6 including a wiring layer 63 and an insulating layer 62, wherein the wiring layer 63 is disposed on the second surface 5b side and has connection pads 631 and 632, and the insulating layer 62 is disposed between the second surface 5b and the wiring layer 63; through-electrodes 210 and 220 that penetrate the semiconductor substrate 5 and the insulating layer 62 and are connected to the connection pads 631 and 632; and annular metal layers 691 and 692 that penetrate the insulating layer 62 and are disposed between the second surface 5b and the wiring layer 63, surrounding the through-electrodes 210 and 220 when viewed from above the semiconductor substrate 5. With this structure, even when wet etching is used to form through-holes 213 and 223 penetrating insulating layer 62, metal layers 691 and 692 function as guard rings, limiting further side etching. Consequently, plasma damage to wiring layer 63, such as that caused by dry etching, is avoided, and patterning defects in the wiring caused by side etching can be suppressed. This results in a highly reliable resonator device 1.

[0065] Furthermore, as described above, when the semiconductor substrate 5 is viewed from above, the metal layers 691 and 692 are included in the range of the connection pads 631 and 632. This can more effectively prevent the etching solution from invading the outside of the metal layers 691 and 692, and can more effectively prevent wiring patterning defects caused by side etching.

[0066] Furthermore, as described above, the integrated circuit 6 includes a plurality of wiring layers 63, 65 stacked in the thickness direction of the semiconductor substrate 5, and the through-electrodes 210, 220 are connected to the lands 631, 632 included in the wiring layer 63 closest to the semiconductor substrate 5 among the plurality of wiring layers 63, 65. This allows the through-electrodes 210, 220 to be shortened as much as possible, making it easier to form the through-electrodes 210, 220.

[0067] Furthermore, as described above, the base 2 includes an etch stop layer 61 made of SiN and disposed between the second surface 5b and the insulating layer 62. This etch stop layer 61 can suppress overetching when dry etching is performed on the semiconductor substrate 5 to form the through-holes 211 and 221, effectively preventing plasma damage to the wiring layer 63.

[0068] Furthermore, as described above, the wiring layer 63 and the through-electrodes 210 and 220 are made of the same material. This improves the compatibility between the through-electrodes 210 and 220 and the wiring layer 63, effectively preventing contact failures therebetween. Furthermore, the shared use of materials reduces the manufacturing cost of the resonator device 1.

[0069] As described above, the vibration element 4 is disposed on the first surface 5a side of the semiconductor substrate 5. Furthermore, the vibration device 1 includes a cover 3 that houses the vibration element 4 between the cover 3 and the base 2. This protects the vibration element 4. Furthermore, by forming the integrated circuit 6 on the second surface 5b side, there is no bonding area with the cover 3 compared to when the integrated circuit 6 is formed on the first surface 5a. Consequently, a larger space can be secured for forming the integrated circuit 6.

[0070] Furthermore, as described above, the manufacturing method of the vibration device 1 includes: a base preparation process S1, preparing a base 2, the base 2 having: a semiconductor substrate 5, which has a first surface 5a and a second surface 5b in a positive and negative relationship with each other; an integrated circuit 6, which includes a wiring layer 63 and an insulating layer 62, the wiring layer 63 is arranged on the side of the second surface 5b and has connecting pads 631, 632, and the insulating layer 62 is arranged between the second surface 5b and the wiring layer 63; annular metal layers 691, 692, which penetrate the insulating layer 62 and are arranged between the second surface 5b and the wiring layer 63; and a through-electrode forming process S2, forming through-electrodes 210, 220, which penetrate the semiconductor substrate 5 and the insulating layer 62, and pass through the inner side of the metal layers 691, 692 to connect with the connecting pads 631, 632. Furthermore, the through-electrode forming step S2 includes a through-hole forming step S21 in which, after dry etching penetrates the semiconductor substrate 5, wet etching penetrates the insulating layer 62, thereby forming through-holes 21 and 22 extending from the first surface 5a through the inner sides of the metal layers 691 and 692 and facing the connection pads 631 and 632; and a conductive material placement step S22 in which a conductive material E is placed within the through-holes 21 and 22 to form the through-electrodes 210 and 220. According to this method, even when wet etching is used to form the through-holes 213 and 223 penetrating the insulating layer 62, the metal layers 691 and 692 function as guard rings, limiting further side etching. Therefore, for example, plasma damage to the wiring layer 63, as occurs during dry etching, is avoided, and wiring patterning defects caused by side etching can be suppressed. Consequently, a highly reliable resonator device 1 is achieved.

[0071] Furthermore, as described above, the base 2 includes an etch stop layer 61 made of SiN and disposed between the second surface 5b and the insulating layer 62. This etch stop layer 61 can suppress overetching when dry etching is performed on the semiconductor substrate 5 to form the through-holes 211 and 221, effectively preventing plasma damage to the wiring layer 63.

[0072] <Second embodiment>

[0073] Figure 15 It is a longitudinal sectional view showing a vibration device according to a second embodiment.

[0074] The vibration device 1 of this embodiment is the same as the vibration device 1 of the first embodiment except that the structure of the base 2 is different. In the following description, the description of this embodiment will focus on the differences from the above embodiment, and the description of the same matters will be omitted. Figure 15 In the embodiment, the same structures as those in the above embodiment are marked with the same reference numerals.

[0075] like Figure 15 As shown, the base 2 of this embodiment is inverted upside down relative to the first embodiment described above, and an integrated circuit 6 is formed on the upper surface side of the semiconductor substrate 5, that is, on the second surface 5b side. In addition, a vibration element 4 is arranged on the upper surface side of the semiconductor substrate 5, and the vibration element 4 and the integrated circuit 6 are joined via a pair of metal bumps 81 and 82. In addition, in order to ensure a joint space with the cover 3 on the second surface 5b of the semiconductor substrate 5, the integrated circuit 6 is formed to be slightly smaller than the base 2 by excluding the outer periphery of the second surface 5b. According to this structure, the integrated circuit 6 can be housed in the housing S together with the vibration element 4 and protected.

[0076] On the terminal layer 68 of the integrated circuit 6, wirings 682 and 683 are arranged to electrically connect the vibration element 4 and the wiring layer 65, instead of the mounting terminals 681 of the first embodiment. Furthermore, on the first surface 5a side of the semiconductor substrate 5, a plurality of mounting terminals 26 are arranged instead of the wirings 28 and 29 described above. Each mounting terminal 26 is electrically connected to the integrated circuit 6 via a through-electrode 230. The through-electrode 230 passes through the annular metal layer 693 formed by penetrating the insulating layer 62 and penetrates the semiconductor substrate 5, the etch stop layer 61, and the insulating layer 62. The through-electrode 230 has the same structure as the through-electrodes 210 and 220 of the first embodiment, and the metal layer 693 has the same structure as the metal layers 691 and 692 of the first embodiment. Furthermore, these are formed using the same method as the first embodiment.

[0077] As described above, in the resonator device 1 of this embodiment, the resonator element 4 is arranged on the second surface 5b side of the semiconductor substrate 5. Furthermore, the resonator device 1 includes a cover 3 that houses the resonator element 4 and the integrated circuit 6 between the cover 3 and the base 2. This protects the resonator element 4 and the integrated circuit 6.

[0078] According to the second embodiment, the same effects as those of the first embodiment can be achieved.

[0079] <Third embodiment>

[0080] Figure 16 It is a cross-sectional view showing a metal layer included in the vibration device according to the third embodiment.

[0081] The vibration device 1 of this embodiment is the same as the vibration device 1 of the first embodiment described above, except that the structures of the metal layers 691 and 692 are different. In the following description, the description of this embodiment will focus on the differences from the above embodiment, and the description of the same matters will be omitted. Figure 16 In the embodiment, the same structures as those in the above embodiment are marked with the same reference numerals.

[0082] like Figure 16 As shown, the resonator device 1 of this embodiment includes multiple concentrically arranged metal layers 691. Specifically, the multiple metal layers 691 include a first metal layer 691a located innermost and surrounding the through-electrode 210; a second metal layer 691b located outside the first metal layer 691a and surrounding the first metal layer 691a; and a third metal layer 691c located outside the second metal layer 691b and surrounding the second metal layer 691b. This structure prevents leakage of etching solution through the triple metal layers 691, thereby more reliably suppressing wiring patterning defects caused by side etching. The number of metal layers 691 is not particularly limited and can be two or four or more.

[0083] Similarly, the resonator device 1 of this embodiment includes multiple concentrically arranged metal layers 692. Specifically, the multiple metal layers 692 include a first metal layer 692a located innermost and surrounding the through-electrode 220; a second metal layer 692b located outside the first metal layer 692a and surrounding the first metal layer 692a; and a third metal layer 692c located outside the second metal layer 692b and surrounding the second metal layer 692b. This structure prevents leakage of etching solution through the triple metal layers 692, thereby more reliably suppressing wiring patterning defects caused by side etching. The number of metal layers 692 is not particularly limited and can be two or four or more.

[0084] As described above, in the resonator device 1 of this embodiment, the metal layers 691 and 692 include the first metal layers 691a and 692a surrounding the through-electrodes 210 and 220 and the second metal layers 691b and 692b surrounding the first metal layers 691a and 692a. This can more reliably suppress wiring patterning defects caused by side etching.

[0085] According to the third embodiment, the same effects as those of the first embodiment can be achieved.

[0086] While the above description of the vibration device and the method for manufacturing the vibration device of the present invention is based on the illustrated embodiments, the present invention is not limited thereto, and the structures of the various components can be replaced with any other structure having the same function. Furthermore, any other components may be added to the present invention. Furthermore, the various embodiments may be appropriately combined.

Claims

1. A vibration device, characterized in that: It has: base; and a vibration element disposed on the base, The base has: a semiconductor substrate having a first surface and a second surface disposed opposite to each other; An integrated circuit comprising a wiring layer and an insulating layer, wherein the wiring layer is arranged on the second surface side and has a connection pad, and the insulating layer is arranged between the second surface and the wiring layer; a through electrode, which penetrates the semiconductor substrate and the insulating layer and is connected to the connection pad; an etch stop layer disposed between the second surface and the insulating layer and composed of SiN; and A ring-shaped metal layer penetrates the insulating layer and is disposed between the second surface and the wiring layer, and surrounds the through-electrode in a plan view of the semiconductor substrate.

2. A vibration device, characterized in that: It has: base; and a vibration element disposed on the base, The base has: a semiconductor substrate having a first surface and a second surface disposed opposite to each other; An integrated circuit comprising a wiring layer and an insulating layer, wherein the wiring layer is arranged on the second surface side and has a connection pad, and the insulating layer is arranged between the second surface and the wiring layer; a through electrode penetrating the semiconductor substrate and the insulating layer and connected to the connection pad; and a ring-shaped metal layer that penetrates the insulating layer and is disposed between the second surface and the wiring layer, and surrounds the through-electrode when the semiconductor substrate is viewed from above; The metal layer includes a first metal layer surrounding the through-electrode and a second metal layer surrounding the first metal layer.

3. The vibration device according to claim 1 or 2, characterized in that When the semiconductor substrate is viewed from above, the metal layer is included in the range of the connection pad.

4. The vibration device according to claim 1 or 2, characterized in that The integrated circuit includes a plurality of wiring layers stacked in the thickness direction of the semiconductor substrate. The through-electrode is connected to the connection pad included in the wiring layer closest to the semiconductor substrate among the plurality of wiring layers.

5. The vibration device according to claim 1 or 2, characterized in that: The wiring layer and the through-electrode are made of the same material.

6. The vibration device according to claim 1 or 2, characterized in that: The vibration element is arranged on the first surface side of the semiconductor substrate, The vibration device includes a cover, and the vibration element is accommodated between the cover and the base.

7. The vibration device according to claim 1 or 2, characterized in that: The vibration element is arranged on the second surface side of the semiconductor substrate, The vibration device includes a cover, and the vibration element and the integrated circuit are accommodated between the cover and the base.

8. A method for manufacturing a vibration device, characterized in that: include: A base preparation step of preparing a base, the base comprising: a semiconductor substrate having a first surface and a second surface in a front-to-back relationship with each other; an integrated circuit including a wiring layer and an insulating layer, the wiring layer being arranged on the second surface side and having a connection pad, the insulating layer being arranged between the second surface and the wiring layer; and a ring-shaped metal layer penetrating the insulating layer and being arranged between the second surface and the wiring layer. a through-electrode forming step of forming a through-electrode that penetrates the semiconductor substrate and the insulating layer and passes through the inner side of the metal layer to connect with the connection pad; and a vibration element placement step of mounting the vibration element on the base after the through-electrode formation step; The through-electrode forming process includes: a through-hole forming step of, after penetrating the semiconductor substrate by dry etching, penetrating the insulating layer by wet etching, thereby forming a through-hole that passes from the first surface through the inner side of the metal layer and faces the connection pad; and The conductive material disposing step is to dispose a conductive material in the through hole to form the through electrode.

9. The method for manufacturing a vibration device according to claim 8, wherein: The susceptor has an etching stopper layer, and the etching stopper layer is arranged between the second surface and the insulating layer and is made of SiN.

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