Microelectromechanical device with moisture-resistant contact pads and method for manufacturing same

Abstract

The invention relates to a micro-electro-mechanical device with moisture-resistant contact pads and a method of manufacturing the same. The MEMS device has a substrate of semiconductor material; a first structural layer of semiconductor material on the substrate; a second structural layer of semiconductor material on the first structural layer; an active portion accommodating an active structure formed in the first structure layer and / or the second structure layer; a connection portion accommodating the plurality of connection structures and arranged transversely to the active portion; and a plurality of conductive regions disposed on the substrate and extending between the active portion and the connection portion. Each connection structure is formed of a first connection portion in electrical contact with a respective conductive region and formed in the first structural layer and a second connection portion on and electrically continuous with the first connection portion, the second connection portion formed in the second structural layer. The first connection portion has a greater thickness than the second connection portion.

Description

Technical Field

[0001] The present disclosure relates to a micro-electromechanical device having a moisture-proof contact pad and a method for manufacturing the same.

[0002] In particular, the inertial MEMS device under consideration comprises one or more inertial sensors, such as accelerometers and / or gyroscopes, formed in at least one silicon structural layer and defining at least one movable structure. The movable structure typically has a main extension in an extension plane and is movable in-plane or out-of-plane. Background Art

[0003] As is known, inertial MEMS devices of this type are increasingly used in consumer, automotive and industrial applications, which typically integrate two or more inertial sensors in the same die and package them together with the associated control circuitry, usually formed in a separate die and forming an ASIC (Application Specific Integrated Circuit).

[0004] These devices are connected to the outside (eg, to the ASIC and / or other external devices) through contact pads.

[0005] For example, Figure 1 An inertial MEMS device (hereinafter referred to as inertial device 1 ) forming a capacitive three-axis accelerometer is shown.

[0006] The inertial device 1 comprises a first sensitive part 2, a second sensitive part 3 and a third sensitive part 4. The sensitive parts 2 to 4 comprise a movable structure having a substantially planar extension parallel to the XY plane of the Cartesian reference system XYZ.

[0007] In particular, in the inertial device 1 shown, the first sensitive part 2 is used to detect oscillations along the first transverse axis X of the Cartesian reference system XYZ; the second sensitive part 3 is used to detect oscillations along the second transverse axis Y of the Cartesian reference system XYZ; and the third sensitive part 4 is used to detect oscillations along the longitudinal axis Z of the Cartesian reference system XYZ.

[0008] For example, Figure 2 As shown in the enlarged details of the figure, the inertial MEMS device 2 can be formed in a tube core 7 of a semiconductor material, including a substrate 8 such as single crystal silicon; an insulating layer 9 such as silicon oxide superimposed on the substrate 7; a structural layer 10 such as single crystal silicon or polycrystalline silicon superimposed on the insulating layer 9; and a cover 11 such as single crystal silicon superimposed and attached to the structural layer 10.

[0009] The structural layer 10 forms a movable structure 15 (eg suspended masses and movable electrodes of the sensitive parts 2 to 4 ) and a fixed structure 16 (eg fixed electrodes of the sensitive parts 2 to 4 , peripheral fixed structures and anchoring regions of the movable structure).

[0010] The movable structure 15 is suspended at a distance above the substrate 8 and the insulating layer 9 and extends at a distance from the cover 11 so as to be able to move freely or in a limited manner.

[0011] The structural layer 10 also forms a connection structure 17 ( Figure 1 ). Connection structure 17 (see also Figure 2 ) are here in the form of columns, separated from each other and from the rest of the structural layer 10 by trenches 20, which are shown here empty but can be filled with at least partially insulating materials and layers to achieve their electrical insulation.

[0012] A soldering layer 18 , which is usually made of a metal such as aluminum Al, gold Au, copper Cu or aluminum copper AlCu, extends over each connection structure 17 .

[0013] Conductive tracks 21 , for example of doped polysilicon, extend above the insulating layer 9 between the fixed structures 16 and the respective connecting structures 17 for biasing the movable structure 15 and the fixed structure 16 and for exchanging signals.

[0014] Further conductive tracks (not shown) may also extend at least partially over the structural layer 10, possibly electrically insulated from the structural layer 10 by a dielectric layer, likewise not shown.

[0015] Figure 2 It is further shown that an insulating region 22 extends over the insulating layer 9 , here in a peripheral region of the inertial device 1 .

[0016] After being mounted on a connection bracket (e.g., a printed circuit board) and connecting the connection structure 17 to external devices, lines and connectors (e.g., via wires not shown), the inertial devices 1 are typically encapsulated in a protective casing of insulating material (such as resin), particularly when they are intended to operate in harsh environments.

[0017] However, the resin packages usually used for the inertial devices under consideration are not completely sealed and can allow the passage of moisture, for example in the presence of complex geometries and in the vicinity of the connection structures 17. However, the presence of humidity may affect the electrical characteristics of the device and, above all, determine its variation over time (drift phenomenon), which affects the reliability of the inertial device.

[0018] In fact, in accelerometers and gyroscopes, for example, the capacitance between the connection structures 17, in particular between the structure connected to the movable mass (rotor) and the detection electrodes, influences the deflection of the inertial device.

[0019] In these devices, these passive capacitors are calibrated during the final test step and the device parameters are fine-tuned based on the initial conditions.

[0020] However, current geometries and dimensions of connection structures 17, particularly when manufactured using a polysilicon deposition process on sacrificial areas that are removed after definition of the mechanical and electrical structures of the sensor, may lead to penetration of wet droplets during operation and significantly alter the electrical characteristics of the device over time.

[0021] For further understanding, refer to Figure 3A , which shows a cross section of the inertial component 1 in the region of the connecting structure 17 .

[0022] Figure 3A Also shown is a packaging material, also called filler and indicated by 25, which covers the surface of the inertial device 1 and extends between the connecting structures 17. Due to the current dimensions of the current structure (where the thickness of the structural layer 10 is even 30 μm), the packaging material 25 may contain air or gas bubbles, such as Figure 3A The air bubbles 26 prevent the filling material from completely filling the space between the connecting structures 17 and may affect the resistivity and capacitance between the connecting structures 17, as shown in FIG. Figure 3A As shown in the resistor 27 and the capacitor 28.

[0023] As previously mentioned, in a final testing step, the inertial device 1 is calibrated to take into account the values ​​of the resistor 27 and the capacitor 28 .

[0024] However, during the lifetime of the device, when exposed to a humid environment, tiny water droplets may penetrate into the non-hermetic packaging material 25 and change the capacitance between the two connection structures 17 .

[0025] For example, Figure 3B The presence of a water drop 30 in contact with the connecting structure 17 is shown.

[0026] The presence of water droplets 30 in the spaces between the connection structures 17 not only changes the capacitance between the connection structures 17 but may also cause a catastrophic condition in the device.

[0027] In fact, water drops may short-circuit two adjacent connection structures 17 , especially in increasingly smaller and more compact current devices, and / or may cause current leakage, especially when they reach the conductive track 21 .

[0028] Since the water droplets cannot escape, this condition will only worsen over time, rendering the inertial device unreliable or even unusable.

[0029] To overcome this problem, a passivation structure can be created that completely surrounds the connection structure 17, for example by forming individual trenches around the individual connection structures 17, coating the trenches with a dielectric layer (e.g., silicon oxide), and filling the trenches with silicon. However, this solution requires an increase in the area required for the connection structure 17, which conflicts with the current trend towards miniaturization.

[0030] Alternatively, in the final manufacturing step, different connection structures can be investigated, removing the columnar regions formed in the structural layer, but this solution requires, in addition to additional manufacturing steps, reduced design flexibility; therefore, this solution is not always available.

[0031] The present disclosure is directed to overcoming the above-mentioned problems. Summary of the invention

[0032] The present disclosure relates to a MEMS device, a packaging device and a method for manufacturing a MEMS device.

[0033] For example, in at least one embodiment of the present disclosure, a MEMS device is summarized as including a substrate of semiconductor material; a first structural layer of semiconductor material superimposed on the substrate and having a first thickness; a second structural layer of semiconductor material superimposed on the first structural layer and having a second thickness; an active portion that accommodates active structures formed in the first structural layer and / or the second structural layer; a connecting portion that accommodates a plurality of connecting structures and is arranged transversely to the active portion; and a plurality of conductive regions arranged above the substrate and extending between the active portion and the connecting portion, wherein each connecting structure includes: a first connecting portion that is electrically contacted with a corresponding conductive region of the plurality of conductive regions and is formed in the first structural layer; and a second connecting portion that is on the first connecting portion and is electrically continuous with the first connecting portion, the second connecting portion being formed in the second structural layer; the first connecting portion having a thickness greater than that of the second connecting portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] For a better understanding of the present disclosure, embodiments thereof will now be described, purely by way of non-limiting example, with reference to the accompanying drawings, in which:

[0035] Figure 1 is a top plan view of a possible layout of an inertial MEMS device;

[0036] Figure 2 It is along Figure 1 The II-II line is intercepted Figure 1 A cross-sectional view of a portion of a device in the region of a connection structure;

[0037] Figure 3A and Figure 3B The results are shown in Figure 2 when air bubbles and water droplets are present. Figure 2Magnified detail of an area of ​​connected structure;

[0038] Figure 4 is a cross-sectional view of at least one embodiment of the present disclosure of a microelectromechanical device in the area of ​​a connection structure;

[0039] Figure 5 It is along Figure 4 A cross section taken along line VV of FIG. 1 , which illustrates the shape of the lower portion of the connecting structure;

[0040] Figure 6 yes Figure 4 A top view of a connection structure among the connection structures;

[0041] Figure 7 yes Figure 4 A top view of a region of a connection structure of a micro-electromechanical device;

[0042] Figure 8 yes Figure 4 An enlarged cross-sectional view of two connection structures of a micro-electromechanical device after packaging;

[0043] Figure 9-12 is a cross section of a semiconductor wafer during successive manufacturing steps, similar to Figure 8 ;as well as

[0044] Fig.13 A cross section of at least one embodiment of the present micro-electromechanical device is shown. DETAILED DESCRIPTION

[0045] The following description relates to the arrangement shown; therefore, expressions such as "above", "below", "upper", "lower", "right", "left" etc. relate to the drawings and should not be interpreted in a limiting manner.

[0046] Figure 4 A portion of a MEMS device 50 is shown. The MEMS device 50 is a general device, such as Figure 1 Inertial device 1.

[0047] The MEMS device 50 is a device made using two polysilicon layers and a sacrificial material area, which is used to define the device structure and is selectively removed to release the movable structure, as described in Italian patent 102020000011755 filed in the name of STMicroelectronics on May 20, 2020, which corresponds to European patent application EP3912953A1 and US patent application US210363000A1.

[0048] In detail, the MEMS device 50 is formed in a tube core 51 of semiconductor material, including a substrate 52 such as single crystal silicon; an insulating layer 53 such as silicon oxide on the substrate 52; a first structural layer 54 of polycrystalline silicon on the insulating layer 53; and a second structural layer 55 of polycrystalline silicon on the first structural layer 54.

[0049] A not shown cap, for example of single crystal silicon, may be arranged on the second structural layer 54 and Figure 4 Attached to the second structural layer in the invisible area (see also Fig.13 device, wherein the cover is indicated by 87).

[0050] The first structural layer 54 and the second structural layer 55 form a movable structure and a fixed structure (not shown), which form an active structure (this means a structure forming a MEMS sensor / actuator). In particular, the structural layers 54, 55 form Figure 1 The suspended masses of the sensitive parts 2 to 4 of the inertial device 1, the movable electrodes and the fixed electrodes (see also Fig.13 8. A device of the type shown, showing a first sensitive portion 85 and a second sensitive portion 86).

[0051] The first structural layer 54 has a thickness greater than that of the second structural layer 55; for example, the first structural layer 54 may have a thickness between 10 μm and 60 μm, in particular, 20 μm, and the second structural layer 55 may have a thickness between 5 μm and 20 μm, in particular, 8.4 μm. In some embodiments, the thickness of the first structural layer 54 may be equal to the upper and lower ends of the range relative to the first structural layer 54 as described above (for example, equal to 10 μm or equal to 60 μm). In some embodiments, the thickness of the second structural layer 55 may be equal to the upper and lower ends of the range relative to the second structural layer 55 as described above (for example, equal to 5 μm or equal to 20 μm).

[0052] The first structural layer 54 and the second structural layer 55 also form a fixed peripheral area, including similar Figure 1 The connecting portion 56 of the connecting portion 19 is formed Figure 4 The connecting structure 57 shown (see also Fig.13 ).

[0053] Each connecting structure 57 (also referred to as a pad) includes a lower portion 57A formed in / by the first structural layer 54 and an upper portion 57B formed in / by the second structural layer 55. In one or more embodiments, the upper portion 57B of the connecting structure 57 extends outward from the lower portion 57A of the connecting structure 57, and in at least one embodiment, the upper portion 57B of the connecting structure 57 at least partially overlaps the middle portion 59 of the connecting structure 56. The lower portion 57A may be referred to as a first portion, and the upper portion 57B may be referred to as a second portion.

[0054] Each lower portion 57A of the connection structures 57 is surrounded by an annular insulating region 58 of dielectric material (e.g., silicon oxide) and is separated from each other by an intermediate portion 59, which is also formed in / by the first structural layer 54. Thus, the intermediate portion 59 is arranged between pairs of adjacent connection structures 57.

[0055] The intermediate portion 59 is coupled here to the electrical ground of the device 50 .

[0056] A conductive region 60 , for example of doped polysilicon, extends above the insulating layer 53 and below the first structure layer 54 , being partially insulated therefrom by an insulating portion 61 .

[0057] The conductive region 60 is formed as a single layer and here comprises a contact region 60A, a shielding region 60B, a first conductive track 60C' and a second conductive track 60C". In at least one embodiment, the second conductive track 60C" is a reference potential line.

[0058] The contact region 60A is arranged below the lower part 57A of the connecting structure 57 and is in direct electrical contact therewith at the first contact region 65 .

[0059] like Figure 5 As shown, the contact region 60A is formed continuously and is therefore electrically connected to the first conductive track 60C'.

[0060] Figure 4 The first conductive track 60C′ schematically shown by dashed lines in FIG. 5 is connected to a corresponding active structure (not shown) of the MEMS device 50, such as a suspended mass, a rotor, a movable electrode or a fixed electrode (e.g., Fig.13 85, 86 in FIG. 8 ), and thus together with the connecting structure 57 form the active part of the MEMS device 50 or the electrical connection between the MEMS structure 50 and the outside.

[0061] The shielding region 60B is arranged below the middle portion 59 of the first structural layer 54 and is in direct electrical contact with it at the second contact region 66 and is therefore also grounded. Figure 5 As shown, the shielding region 60B is formed contiguously with the second conductive track 60C" and is therefore electrically connected thereto.

[0062] Figure 4 A second conductive track 60C″, schematically shown by dashed lines in FIG. 5 , is coupled to a grounded portion of the MEMS device 50 (eg, coupled to a non-biased movable or fixed electrode via a contact structure 57 ).

[0063] Furthermore, one of the contact structures 57 may allow the ground of the device to be provided externally.

[0064] The shielding region 60B surrounds the contact region 60A at a certain distance and is insulated therefrom by some insulating portions 61 .

[0065] The shielding area 60B here has an open annular shape for the first conductive track 60C' to pass through. Figure 5 shown.

[0066] Thus, the shielding region 60B is electrically insulated with respect to the contact region 60A and the first conductive track 60C′ and shields the contact region 60A in order to avoid or at least limit parasitic effects and leakages.

[0067] For example, the insulating portion 61 may be a part of a sacrificial insulating layer and be interrupted at the first contact region 65 and the second contact region 66 .

[0068] An example of the conductive region 60 is Figure 5 As shown, the lower portion 57A of the connecting structure 57 is not shown. Specifically, Figure 5 The contact areas 65, 66 and the annular insulating area 58 are shown, and the boundaries of the contact area 60A and the shielding area 60B and a part of the first and second conductive tracks 60C', 60C" are shown with dashed lines.

[0069] Reference again Figure 4 The insulating layer forming the insulating portion 61 may be a first sacrificial layer for releasing the suspension structure during the manufacturing process of the MEMS device 50, as described in the aforementioned Italian Patent No. 102020000011755 (e.g., in Fig.13 The sensitive parts 85 and 86 are removed).

[0070] The passivation layer 62 extends over the first structural layer 54 .

[0071] In addition, here, the passivation layer 62 also partially extends between the lower portion 57A and the upper portion 57B of each connection structure 57, as shown in FIG. Figure 6 As shown by the dashed line in FIG. 8 , the edge of the opening 88 of the passivation layer 62 is indicated, where the first structure layer 54 and the second structure layer 55 are in direct contact.

[0072] exist Figure 4 , the portion of passivation layer 62 extending between lower portion 57A and upper portion 57B of each connection structure 57 is indicated by 62A and helps prevent water or moisture droplets from reaching critical areas of contact structures 57, as described below.

[0073] A welding or soldering region 63 , which is typically made of a metal such as aluminum Al, gold Au, copper Cu, or aluminum copper AlCu, extends over each connection structure 57 , making direct contact with the upper portion 57B of the connection structure 57 .

[0074] The upper portions 57B of the connecting structures 57 are spaced apart from each other, as shown in FIG. Figure 7 As shown in the top view, multiple connection structures 57 are shown, and for the convenience of explanation, only the welding area 63 is shown with solid lines, and the annular insulating area 58, the contact area 60A and the first conductive track 60C′ of some connection structures 57 are shown with dotted lines.

[0075] When the MEMS device 50 is packaged, some packaging material 70 is molded, covers the connection structures 57 , and fills the space between the upper portions 57B of the connection structures 57 .

[0076] In this case, reference Figure 8 ,and Figure 2 , Figure 3A and Figure 3B Compared with the structure of FIG. 5 , since the height of the second structural layer 55 is reduced, and therefore the height of the upper portion 57B of the connecting structure 57 is also reduced, the air or gas bubbles 71 (even if larger in size) are less likely to contact two adjacent connecting structures 57 .

[0077] In any case, due to the height of the first structural layer 54 and the presence of the passivation layer 62, the annular insulating region 58 and the insulating portion 61 (which as a whole form a tortuous moisture-proof path), any moisture that penetrates into the packaging material 70 and penetrates under the bubble 71 formed between the two upper portions 57B cannot reach the conductive region 60.

[0078] Furthermore, the lower height of the upper portion 57B of the connection structure 57 relative to the lower portion 57A results in a smaller facing area of ​​the upper portion 57B relative to the facing area of ​​the lower portion 57A, thereby reducing the risk of electrical connection under wet conditions.

[0079] The intermediate regions 59 arranged between adjacent connecting structures 57 connected to ground form spacers which electrically separate the connecting structures 57 from each other, avoiding parasitic coupling for most of their height and thereby allowing them to be placed very close to each other.

[0080] Furthermore, during the encapsulation step, the intermediate region 59 avoids incomplete resin filling between the contact pads and, as described above, thus avoids possible leakage between the contact pads in the presence of humidity.

[0081] For example, in this way, the connection structures 57 may be arranged such that their upper portions 57B and / or lower portions 57A are at least 20 μm apart.

[0082] The MEMS device 50 may be Figures 9 to 12 Formed as shown.

[0083] Fig. 9A first wafer 80 of semiconductor material is shown which has undergone initial processing steps, as described in the above-mentioned Italian Patent 102020000011755.

[0084] In particular, the first wafer 80 includes a substrate 52 on which an insulating layer 53 has been formed, such as a thermally grown or deposited insulating layer.

[0085] Conductive regions 60 have been formed on insulating layer 53, for example by deposition of a doped polysilicon layer and subsequent photolithographic definition.

[0086] A first sacrificial layer of, for example, silicon oxide is deposited and patterned over the conductive area 60, intended to form an insulating portion 61. The first sacrificial layer has been selectively removed over the conductive structure 60, where the contact areas 65, 66 are to be grown, as well as any other anchoring and electrical and / or mechanical connection portions requiring electrical / mechanical connection between the active structure of the MEMS device 50 formed in the first structural layer 54 and the substrate 50. Thus, in this step, the insulating portion 61 is defined.

[0087] Furthermore, using an epitaxial growth process, the first structure layer 54 has been grown to form the contact regions 65 , 66 .

[0088] exist Fig. 9 In the need to form Fig.13 In the region of the sensitive portions 85 , 86 , the first structure layer 54 has been etched, for example by dry etching, to form a trench 68 which penetrates the first structure layer 54 and defines a lower portion 57A and an intermediate portion 59 of the connection structure 57 .

[0089] exist Fig.10 In the embodiment of the present invention, a second sacrificial layer is deposited to also form a passivation layer 62. The second sacrificial layer / passivation layer 62 is, for example, a TEOS (tetraethyl orthosilicate) layer, and its thickness is, for example, between 0.1 μm and 5 μm. The second sacrificial layer / passivation layer 62 fills the trench 68 to form the annular insulating region 58, and is planarized and selectively removed to form the passivation layer 62 and the opening 88.

[0090] Then, if Fig.11 As shown, the second structure layer 55 is grown over the first structure layer 54 and the passivation layer 62. The second structure layer 54 is epitaxially grown and planarized, for example, by CMP (chemical mechanical polishing), so that in the absence of the passivation layer 62 (for example, at the opening 88 in the connection portion 56), a structure layer having a thickness equal to the sum of the thicknesses of the first structure layer 54 and the second structure layer 55 is formed.

[0091] Then, a welding region 63 of, for example, AlCu is formed.

[0092] The welding region 63 may be formed by depositing and patterning a metal layer.

[0093] Then, in a manner not shown, the active structure of the MEMS device 50 formed by the second structural layer 55 alone or by the two structural layers 54, 55 is defined, in particular for defining Fig.13 The movable mass of the sensitive parts 85, 96 and the fixed and movable electrodes.

[0094] Subsequently, likewise in a manner not shown, the movable structure is released by selectively removing the first sacrificial layer 61 in a manner not visible.

[0095] Then, a cap wafer is attached to the first wafer 80 ( Fig.13 ); the first wafer 80 may be thinned, for example by lapping, to have a desired thickness; and the cover wafer may be cut, for example by dry etching, to open a window above the connection portion 56. In this step, as Fig.12 As shown, the second structure layer 55 is defined to form the upper portion 57B of the connection structure 57 , again by dry etching and using the welding region 63 as a mask.

[0096] Subsequently, the entire wafer is cut to form the inertial MEMS devices 50 .

[0097] An example of the inertial MEMS device 50 thus obtained is Fig.13 , which shows the connecting portion 56 and the first sensitive portion 85 and the second sensitive portion 86 (similar to Figure 1 Here, the first sensitive part 85 is formed by the single first structural layer 54, and the second sensitive part 86 is formed by the two structural layers 54, 55, but other active structures (i.e., structures forming the MEMS sensor / actuator) can also be formed in the single second structural layer 55.

[0098] In detail, Fig.13 Shown are substrate 52 ; first structural layer 54 ; second structural layer 55 ; passivation layer 62 ; conductive region 60 ; and cover 87 , which covers sensitive portions 85 , 86 and is bonded to second structural layer 55 .

[0099] Fig.13 Also shown is a wire 90 soldered to one of the connection structures 57 and a portion of the encapsulation material 70 forming a packaged device 91 .

[0100] Finally, it is evident that modifications and variations may be made to the devices and the methods of manufacture described and illustrated herein without departing from the scope of the present disclosure as defined in the appended claims.

[0101] For example, although the description specifically relates to inertial MEMS devices, the described solutions are also applicable to other types of MEMS devices that have connection areas that may be reached by humidity and water droplets during use and may modify the electrical parameters of the devices in an undesirable way.

[0102] The shielding area 60B may be absent.

[0103] The opening 88 above the lower portion 57A of the connecting structure 57 (see, for example, Fig.10 ) can have a larger area than shown, for example approximately equal to the area of ​​the lower portion 57A, while maintaining electrical insulation between the upper portion 57B and the middle portion 59.

[0104] At least one embodiment of a MEMS device (50) disclosed herein is summarized as comprising: a substrate (52) of semiconductor material; a first structural layer (54) of semiconductor material superimposed on the substrate (52) and having a first thickness; a second structural layer (55) of semiconductor material superimposed on the first structural layer (54) and having a second thickness; an active portion (83) accommodating active structures (85, 86) formed in the first structural layer (54) and / or the second structural layer (55); a connecting portion (56) accommodating a plurality of connecting structures (57) and arranged transversely to the active portion (85, 86); and a layout A plurality of conductive regions (60) are disposed above a substrate (52) and extend between active portions (85, 86) and a connecting portion (56), wherein each connecting structure (57) includes: a first connecting portion (57A) electrically contacting a corresponding conductive region (60A) among the plurality of conductive regions (60) and formed in a first structural layer (54); and a second connecting portion (57B) on and electrically continuous with the first connecting portion (57A), the second connecting portion (57) being formed in a second structural layer (55); the first connecting portion (57A) having a thickness greater than a thickness of the second connecting portion (57B).

[0105] In at least one embodiment, the first connection portion (57A) of each connection structure (57) is surrounded by a corresponding annular insulating region (58) of dielectric material, wherein the annular insulating region (58) may have a height equal to the first thickness.

[0106] In at least one embodiment, an intermediate region (59) formed in the first structural layer (54) extends between adjacent connecting structures (57) and is electrically insulated from the connecting structures (57) by the annular insulating region (58).

[0107] In at least one embodiment, the intermediate region (59) is coupled to a reference potential line (60C").

[0108] In at least one embodiment, the conductive region (60) includes a contact region (60A) in direct electrical contact with the connecting structure (57), a shielding region (60B) in direct electrical contact with the intermediate region (59), and conductive tracks (60C′, 60C″) electrically coupling the connecting structure (57) and the intermediate region (59) with the active structure (85, 86) in the active portion (83).

[0109] In at least one embodiment, the shielding region (60B) surrounds the corresponding contact region (60A) at a distance.

[0110] In at least one embodiment, a passivation layer (62) of dielectric material extends locally on the first structural layer (54), and partially extends between the first connecting portion and the second connecting portion (57A, 57B) of the connecting structure (57), and is in direct contact with the annular insulating area (58).

[0111] In at least one embodiment, the first thickness is between 10 μm and 60 μm, and the second thickness is between 5 μm and 20 μm.

[0112] In at least one embodiment, the MEMS device further includes a metal region (63) overlying the second connecting portion (57B).

[0113] In at least one embodiment, a packaged device (91) of the present disclosure is summarized as including a MEMS device (50) and also including a packaging material (70) covering the connection structure (57) and extending between the second connection portions (57B).

[0114] At least one embodiment of a method for manufacturing a MEMS device disclosed herein is summarized as: forming a plurality of conductive regions (60) on a substrate (52) of semiconductor material; forming a first structural layer (54) of semiconductor material (60), the first structural layer (54) having a first thickness; selectively removing the first structural layer (54) to form a first connection portion (57A) on at least some of the conductive regions (60) and in contact with at least some of the conductive regions; forming a second structural layer (55) of semiconductor material on the first structural layer (54), the second structural layer (55) having a second thickness and in direct contact with the first connection portion (57A); and selectively removing the second structural layer (55) to form a second connection portion (57B), wherein selectively removing the first structural layer (54) and / or the second structural layer (55) includes defining an active region in an active portion of the MEMS device, and the first connection portion (57A) has a greater thickness than the second connection portion (57B).

[0115] In at least one embodiment, the method further includes, before forming the second structural layer (55): forming a groove (68) in the first structural layer (54), the groove laterally defining the first connecting portion (57A); filling the groove (68) with a dielectric material to form an annular insulating region (58) surrounding the first connecting portion (57A); forming a passivation layer (62) of dielectric material on the first structural layer (54); and partially removing the passivation layer to form an opening (88) above the first connecting portion (57A) of the connecting structure (57).

[0116] In at least one embodiment, selectively removing the second structural layer (55) includes forming a metal region (63) on the second structural layer (54) vertically aligned with the first connection portion (57A), and removing the exposed second structural layer (55).

[0117] In at least one embodiment, forming a plurality of conductive regions (60) includes: forming a contact region (60A) under the connecting structure (57) in electrical contact with the connecting structure; forming a shielding region (60B) under the intermediate region (59) of the first structural layer in electrical contact with the intermediate region, the intermediate region (59) being between adjacent connecting structures (57); and forming conductive tracks (60C′, 60C″) that electrically couple the connecting structure (57) and the intermediate region (59) with the active region.

[0118] The various embodiments described above can be combined to provide further embodiments. Aspects of the embodiments can be modified, if necessary, to employ concepts of the various patents, applications and publications to provide further embodiments.

[0119] These and other changes can be made to the embodiments in light of the above detailed description. Generally, in the following claims, the terms used should not be interpreted as limiting the claims to the specific embodiments disclosed in the specification and claims, but should be understood to include all possible embodiments and the full range of equivalents to which these claims are entitled. Therefore, the claims are not limited by this disclosure.

Claims

1. A MEMS device, comprising: Substrates of semiconductor materials; a first structural layer of semiconductor material superposed on the substrate and having a first thickness; a second structural layer of semiconductor material, superimposed on the first structural layer and having a second thickness; an active portion accommodating an active structure formed in the first structural layer and / or the second structural layer; a connection portion accommodating a plurality of connection structures and arranged transversely to the active portion; as well as a plurality of conductive regions disposed above the substrate and extending between the active portion and the connecting portion, Each connection structure includes: a first connection portion electrically contacting a corresponding conductive region among the plurality of conductive regions and formed in the first structure layer; and a second connection portion on the first connection portion and electrically continuous with the first connection portion, the second connection portion being formed in the second structural layer; The first connection portion has a greater thickness than the second connection portion. 2 . The MEMS device of claim 1 , wherein the first connection portion of each connection structure is surrounded by a corresponding annular insulating region of dielectric material, wherein the annular insulating region has a height equal to the first thickness. 3 . The MEMS device according to claim 2 , wherein the intermediate region formed in the first structural layer extends between adjacent connection structures and is electrically insulated from the connection structures by the annular insulating region. The MEMS device of claim 3 , wherein the intermediate region is coupled to a reference potential line.

5. The MEMS device according to claim 3, wherein the conductive region comprises: a contact region in direct electrical contact with the connection structure; a shielding region in direct electrical contact with the intermediate region; as well as Conductive tracks electrically couple the connection structure and the intermediate region with the active structure in the active portion. The MEMS device according to claim 5 , wherein the shielding area surrounds the corresponding contact area at a certain distance. 7 . The MEMS device of claim 2 , wherein a passivation layer of dielectric material extends locally on the first structural layer and partially between the first connection portion and the second connection portion of the connection structure and is in direct contact with the annular insulating region. 8 . The MEMS device of claim 1 , wherein the first thickness is between 10 μm and 60 μm, and the second thickness is between 5 μm and 20 μm.

9. The MEMS device of claim 1, further comprising a metal region overlying the second connection portion.

10. A method for manufacturing a MEMS device, the method comprising: forming a plurality of conductive regions on a substrate of semiconductor material; forming a first structural layer of semiconductor material, the first structural layer having a first thickness; selectively removing the first structure layer to form first connection portions on at least some of the conductive regions and in contact with the at least some of the conductive regions; forming a second structure layer of semiconductor material on the first structure layer, the second structure layer having a second thickness and directly contacting the first connecting portion; as well as selectively removing the second structural layer to form a second connecting portion, wherein selectively removing the first structural layer and the second structural layer includes defining an active area in an active portion of the MEMS device, and The first connection portion has a greater thickness than the second connection portion.

11. The method according to claim 10, further comprising, before forming the second structural layer: forming a groove in the first structural layer, the groove laterally defining the first connecting portion; filling the trench with a dielectric material to form an annular insulating region surrounding the first connecting portion; forming a passivation layer of dielectric material on the first structural layer; as well as The passivation layer is partially removed to form an opening over the first connection portion of the connection structure.

12. The method of claim 10, wherein selectively removing the second structural layer comprises: A metal region vertically aligned with the first connection portion is formed on the second structure layer, and the exposed second structure layer is removed.

13. The method of claim 10, wherein forming the plurality of conductive regions comprises: forming a contact region below the connection structure in electrical contact with the connection structure; forming a shielding region below a middle region of the first structural layer and in electrical contact with the middle region, the middle region being interposed between adjacent connection structures; as well as Conductive tracks are formed that electrically couple the connection structure and the intermediate region with the active region.

14. A device comprising: MEMS devices, including: Substrates of semiconductor materials; an insulating layer on the substrate; a contact region on the insulating layer; an insulating portion on the insulating layer; a shielding region on the insulating layer, the shielding region being spaced outwardly from the contact region and extending around the contact region; a first connection structure on the insulating portion, the first connection structure including an intermediate portion coupled to the shielding region; a second connection structure on the contact region, the second connection structure comprising a first portion coupled to the contact region and a second portion coupled to the first portion, and the first portion extends from the contact region to the second portion; a passivation layer extending between the middle portion of the first connection structure and the first portion of the second connection structure, the passivation layer separating the middle portion of the first connection structure from the first portion of the second connection structure, and the passivation layer between the first portion of the second connection structure and the second portion of the second connection structure; a first conductive track coupled to the contact area; and A second conductive track is coupled to the shielding region.

15. A device as claimed in claim 14, wherein the second conductive track is a reference potential line. 16 . The device of claim 14 , further comprising a welding region or a fusion welding region on the second portion of the second connection structure. 17 . The device of claim 14 , wherein the middle portion of the first connection structure includes a surface facing away from the substrate, and the passivation layer completely covers the surface of the middle structure. 18 . The device of claim 17 , further comprising an encapsulation material covering the first connection structure and the second connection structure, and the encapsulation material is separated from the middle portion of the first connection structure by the passivation layer.

19. The device of claim 14, wherein the second portion of the second connection structure extends outwardly from the first portion of the second connection structure.

20. The device of claim 19, wherein the second portion of the second connection structure extends over the middle portion of the first connection structure.

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