Microelectromechanical optical shutter with translational shielding structure and manufacturing process thereof

Abstract

Embodiments of the present disclosure relate to microelectromechanical optical shades with translational shielding structures and manufacturing processes thereof. The MEMS shade includes: a semiconductor substrate with an aperture therethrough; a first semiconductor layer and a second semiconductor layer forming a support structure fixed to the substrate; a plurality of deformable structures, each deformable structure formed from a corresponding portion of at least one of the first and second semiconductor layers; a plurality of actuators; a plurality of shielding structures, each shielding structure formed from a corresponding portion of at least one of the first and second semiconductor layers, the shielding structures angularly arranged about the underlying aperture to provide shielding of the aperture, each shielding structure further coupled to the support structure via a deformable structure. Each actuator can be controlled to translate the corresponding shielding structure between a first position and a second position, thereby varying the shielding of the aperture; the first and second positions of the shielding structures being such that, in at least one operating state, adjacent shielding structures at least partially overlap one another.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to MEMS (Micro-Electro-Mechanical System) optical shutter including a translation shielding structure and related manufacturing processes. BACKGROUND

[0002] It is known that nowadays mobile phones are equipped with improved camera modules, which guarantee a performance level comparable to that of professional cameras. Such modules include sensors that are progressively larger and have progressively higher performance; however, it is known that only a few solutions are able to implement a typical feature of professional cameras: variable optical aperture.

[0003] For example, US 2019 / 0377174 describes a MEMS optical shutter including a pinhole, a blade and an actuator designed to move the blade transversely with respect to the pinhole. However, this solution has only a small number of degrees of freedom for adjusting the optical aperture; in particular, the adjustment of the optical aperture is limited to a portion of the periphery of the optical aperture. SUMMARY

[0004] Therefore, the present disclosure aims to provide a solution that at least partially overcomes the drawbacks of the prior art.

[0005] The present disclosure relates to MEMS optical shutter and related manufacturing processes. For example, the present disclosure relates to a device comprising: a micro-electromechanical shutter having a substrate; an aperture through the substrate; a plurality of cantilever structures coupled to the substrate around the aperture; a plurality of first shielding zones coupled to first cantilever structures of the plurality of cantilever structures; and a plurality of second shielding zones coupled to second cantilever structures of the plurality of cantilever structures, the plurality of second shielding zones being closer to the aperture than the plurality of second shielding zones. The shutter comprises adjacent first shielding zones of the plurality of first shielding zones, the adjacent first shielding zones being spaced apart from each other by one of the plurality of second shielding zones. A plurality of first spring structures is located between the plurality of first shielding zones and the corresponding cantilever structures, and a plurality of second spring structures is located between the plurality of second shielding zones and the corresponding cantilever structures. BRIEF DESCRIPTION OF DRAWINGS

[0006] 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 attached drawings, wherein:

[0007] FIGS. 1A-1B is a schematic cross-sectional view of a MEMS shutter, FIG. 1B taken along FIG. 2 the section line IB-IB shown;

[0008] FIG. 2 is a schematic top view of the MEMS shutter shown partially removed; FIG. 1B

[0009] FIG. 3 ​is FIG. 1A partially sectioned view of a portion of the MEMS shutter shown in

[0010] FIG. 4 is FIG. 3 schematic top view of a portion of the MEMS shutter shown in

[0011] FIG. 5A and FIG. 5B are FIG. 4 schematic cross-sectional views of the MEMS shutter shown in

[0012] FIG. 6 is FIG. 1A partially sectioned view of another portion of the MEMS shutter shown in

[0013] FIG. 7 is FIG. 6 partially sectioned view of a portion of the MEMS shutter shown in

[0014] FIG. 8 is a schematic top view of a variant of the MEMS shutter shown in

[0015] FIG. 9 is FIG. 8 schematic top view of a portion of the MEMS shutter shown in

[0016] FIG. 10 is FIGS. 8-9 schematic cross-sectional view of a portion of the MEMS shutter shown in FIG. 9

[0017] FIG. 11 is a schematic top view of a variant of the MEMS shutter shown in

[0018] FIG. 12 and FIG. 15 is a schematic top view of a variant of the MEMS shutter shown in

[0019] FIG. 13A and FIG. 14A is FIG. 12 schematic top view of portions of the MEMS shutter shown in

[0020] FIG. 13B and FIG. 14B is FIG. 12 schematic cross-sectional views of portions of the MEMS shutter shown in FIG. 13A and FIG. 14A ​schematic cross-sectional view taken along the section lines XIIIB-XIIIB and XIVB-XIVB shown;

[0021] FIG. 16A is FIG. 15 schematic top view of a portion of the MEMS shield shown;

[0022] FIG. 16B is FIG. 15 schematic cross-sectional view of a portion of the MEMS shield shown along FIG. 16A schematic cross-sectional view of a portion taken along the section line XVIB-XVIB shown;

[0023] FIGS. 17-31 is a schematic cross-sectional view of a semiconductor wafer during successive steps of a manufacturing process;

[0024] FIG. 32 and FIG. 33 is a schematic cross-sectional view of a semiconductor wafer during successive steps of a variant of the manufacturing process;

[0025] FIG. 34 is another schematic cross-sectional view of a semiconductor wafer during a manufacturing process; and

[0026] FIG. 35 is a schematic cross-sectional view of a variant of the MEMS shield. DETAILED DESCRIPTION

[0027] FIG. 1A A MEMS shield 1 is shown, which comprises a substrate 2 of semiconductor material (e.g. silicon) and a first dielectric region 4 arranged on the substrate 2 and formed of thermal oxide.

[0028] In particular, the substrate 2 is delimited by a top surface S a and a bottom surface S b parallel to the plane XY of an orthogonal reference system XYZ. The first dielectric region 4 extends on the top surface S a and laterally delimits a window W leaving a central portion of the top surface S a exposed; in other words, the first dielectric region 4 extends on a peripheral portion of the top surface S a .

[0029] The MEMS shield 1 further comprises a second dielectric region 6, for example made of aluminum oxide (alumina) and extending on a peripheral portion of the first dielectric region 4 leaving an internal portion of the first dielectric region 4 exposed, the first dielectric region 4 laterally delimiting the above-mentioned window W.

[0030] A main aperture 9 extends through the substrate 2 starting from the bottom surface S b and extending to the top surface Sa The sidewalls of the substrate can taper outwardly from the bottom surface to the top surface at the main aperture 9. In the following, for simplicity of description and without any loss of generality, the symmetry axis of the main aperture 9 coincides with the symmetry axis H of the MEMS shutter 1, parallel to the axis Z. Moreover, according to a first approximation, the main aperture 9 has, for example, a truncated conical shape or a truncated pyramidal shape with a polygonal base, the minor base lying in the plane of the bottom surface S b

[0031] The window W communicates with the underlying main aperture 9 and is delimited at the bottom by a wall P formed by a portion of the substrate 2 which laterally delimits the top of the main aperture 9 and has a planar and hollow shape. The wall P lies in the plane of the top surface S a

[0032] The MEMS shutter 1 further comprises an electrically conductive layer 7 having, in a top view, a closed shape (for example, polygonal or circular) so as to surround the main aperture 9.

[0033] In particular, the electrically conductive layer 7 has an approximately U-shaped cross section so as to delimit a trench T.

[0034] An outer portion of the electrically conductive layer 7 covers, at the sides and at the top, the above-mentioned inner portion of the first dielectric region 4 and, at the top, further covers the portion of the second dielectric region 6 facing the symmetry axis H. A bottom portion of the electrically conductive layer 7 covers an outer portion of the wall P; an inner portion of the electrically conductive layer 7 extends in a cantilevered manner from the bottom so as to cover, at a distance, a portion of the inner portion of the wall P.

[0035] The MEMS shutter 1 further comprises a plurality of anchoring regions (two of which are shown in FIG. 1A and denoted by 8) made of polysilicon and extending on the second dielectric region 6. In particular, the anchoring regions 8 are arranged at a lateral distance from the electrically conductive layer 7 and are arranged outside the electrically conductive layer 7.

[0036] The MEMS shutter 1 further comprises a first semiconductor layer 14 and a second semiconductor layer 16 made of polysilicon, as shown in FIG. 2 , which form a plurality of first shielding structures 33 and a plurality of second shielding structures 35. In conjunction FIG. 2 , FIG. 2 with reference to the embodiment illustrated in FIG. 1B , this differs from the embodiment shown in FIG. 1A for the shape of the main aperture 9. In the following, the description will be limited to the embodiment described in FIG. 1A ; however, reference will be made to FIG. 2 as far as they also apply to the embodiment shown in FIG. 1A .

[0037] ​​Each of the first and second shielding structures 33, 35 is associated with a corresponding radial direction R parallel to the plane XY FIG. 3 One of them is indicated by R. As shown in FIG. 2 the present example, it is assumed that both the first and second shielding structures 33, 35 are four. Moreover, it is intended that each of the first and second shielding structures 33, 35 is associated with a corresponding transversal direction TR perpendicular to the plane ZR; it is therefore perpendicular to the corresponding radial direction R.

[0038] In more detail, the first semiconductor layer 14 forms: a support region 18 which directly contacts the corresponding anchoring region 8; a bottom peripheral region 20; and a bottom internal structure 22 which will be described in detail below.

[0039] The bottom peripheral region 20 forms a fixed bottom peripheral region 20’ which directly contacts the support region 18.

[0040] Moreover, for each of the first and second shielding structures 33, 35, the bottom peripheral region 20 forms a corresponding mobile bottom peripheral region 20” which extends in a cantilevered manner from the fixed bottom peripheral region 20’. In particular, if we indicate with S ref the top surface of the second dielectric region 6, the mobile bottom peripheral region 20” covers the surface S ref at a certain distance.

[0041] The second semiconductor layer 16 forms a top peripheral region 26 and a top internal structure 30 which will be described in more detail below.

[0042] The top peripheral region 26 comprises a fixed top peripheral region 26’ which directly contacts the fixed bottom peripheral region 20’ forming a fixed peripheral structure 28 with the bottom peripheral region 20’.

[0043] Moreover, for each of the first and second shielding structures 33, 35, the top peripheral region 26 forms a corresponding mobile top peripheral region 26” which directly contacts and extends on the corresponding mobile bottom peripheral region 20” forming a corresponding cantilevered structure 29 with the mobile bottom peripheral region 20”, which extends in a cantilevered manner from the fixed peripheral structure 28 mentioned above.

[0044] As shown in FIGS. 2-3 , each cantilevered structure 29 comprises a main portion 27A and an auxiliary portion 27B which will be described below; the main portion 27A is also visible in FIG. 1A , but only roughly visible. In this regard, the drawings are not shown to scale. On the contrary, FIG. 3The spacing between the first and second semiconductor layers 14 and 16 is not shown; on the other hand, this spacing does not correspond to a physical interface, but rather represents the fact that the first and second semiconductor layers 14 and 16 (although made of the same material) were formed at different times, as described below.

[0045] As mentioned above, refer to FIG. 1A and FIG. 3 The cantilever structure 29 shown corresponds to the first shielding structure 33 (but this description also applies to other cantilever structures 29, even if they are coupled to the second shielding structure 35), with the first end of the main portion 27A fixed relative to the corresponding portion of the fixed peripheral structure 28. FIG. 2 (Only one is shown in the image); the auxiliary part 27B is arranged between the main part 27A and the first shielding structure 33.

[0046] More specifically, in its stationary state, the main portion 27A has a planar shape and extends along an axis oriented at 90° relative to the radial direction R, while the auxiliary portion 27B extends in the radial direction R and has an approximately parallelepiped shape. The first end of the auxiliary portion 27B is fixed relative to the second end of the main portion 27A.

[0047] Without affecting generality, in the static state and top view, the main portion 27A has a shape that tapers towards the auxiliary portion 27B, thereby defining a recess 99 having, for example, a triangular shape (one of which is... FIG. 2 (As shown). However, the shape of the auxiliary part 27A can vary relative to what is shown.

[0048] Refer again FIG. 1A For each of the first and second shielding structures 33 and 35, the MEMS shielding member 1 includes a corresponding piezoelectric actuator 36 that extends on the main portion 27A of the corresponding cantilever structure 29.

[0049] Each actuator 36 includes: a first electrode 37 disposed on the main portion 27A of the corresponding cantilever structure 29 and made of, for example, a material selected from Mo, Pt, Ti, Al, and TiW; a piezoelectric region 38 disposed on the first electrode 37 and made of, for example, a material selected from PZT, AlN, and scandium-doped AlN; a second electrode 39 disposed on the piezoelectric region 38 and made of, for example, a material selected from Mo, Pt, Ti, Al, and TiW; and a protective region 34 made of, for example, a material selected from silicon oxide, silicon nitride, and aluminum nitride, extending over the second electrode 39 and laterally surrounding the first and second electrodes 37, 39 and the piezoelectric region 38 until it contacts the main portion 27A of the corresponding cantilever structure 29. In a manner known per se, and therefore not described or shown in detail, a voltage can be applied between the first and second electrodes 37, 39, for example, by means of suitable electrical contacts (not shown), which enables the actuator 36 to operate.

[0050] Referring again to the first and second shielding structures 33 and 35, they are formed by the bottom inner structure 22 and the top inner structure 30.

[0051] More specifically, the first shielding structures 33 are identical to each other and are spaced apart at equal angular distances with respect to the axis of symmetry H in a static state; specifically, pairs of first adjacent shielding structures 33 are spaced apart at an angular distance of 90°. The second shielding structures 35 are identical to each other and are spaced apart at equal angular distances with respect to the axis of symmetry H; specifically, pairs of second adjacent shielding structures 35 are spaced apart at an angular distance of 90°. Furthermore, the first shielding structures 33 and the second shielding structures 35 are arranged to alternate with each other at a certain angular distance. Each first shielding structure 33 is thus arranged at an angle between the second adjacent shielding structure pairs 35, which are 45° away from the first shielding structure 35; similarly, each second shielding structure 35 is arranged at an angle between the first adjacent shielding structure pairs 33, which are 45° away from the second shielding structure 35.

[0052] In the following text, see references FIG. 1A and FIG. 3 To describe the first shielding structure 33, as previously mentioned, only one first shielding structure 34 is visible.

[0053] In detail, the first shielding structure 33 includes a corresponding top shielding region 40 formed by the internal moving portion 30 of the second semiconductor layer 16 and a lower bottom auxiliary region 42 formed by the internal moving portion 22 of the first semiconductor layer 14.

[0054] The top shielding area 40 has a rectangular shape and an L-shaped cross-section in the top view. Specifically, the top shielding area 40 includes a main portion 45 and an auxiliary portion 46. The main portion 45 has a parallelepiped shape with its axis parallel to the radial direction R, and its ends face the axis of symmetry H and the top peripheral area 26, respectively. The auxiliary portion 46 has a parallelepiped shape and is arranged below the end of the main portion 45 facing the top peripheral area 26.

[0055] The bottom auxiliary area 42 includes a corresponding main part 48 and a corresponding auxiliary part 49. The main part 48 has a parallelepiped shape with its axis parallel to the radial direction R and its ends facing the bottom peripheral area 20 and the axis of symmetry H, respectively. The auxiliary part 49 has a parallelepiped shape and is arranged below the end of the main part 48 facing the axis of symmetry H.

[0056] The auxiliary portion 46 of the top shielding region 40 directly covers the end of the main portion 48 of the bottom auxiliary region 42 facing the bottom peripheral region 20. Extending below the auxiliary portion 49 of the bottom auxiliary region 42 is a suspended conductive region 50 made of polysilicon.

[0057] In the first approximate case, and without implying any loss of generality, the main portions 45, 48 and auxiliary portions 46, 49 of the top shielding region 40 and the bottom auxiliary region 42 have the same extension in the lateral direction TR associated with the first shielding region 33.

[0058] More specifically, the main portion 45 of the top shielding region 40 and the main portion 48 of the bottom auxiliary region 42 extend cantileveredly from the auxiliary portion 46 of the top shielding region 42 toward the axis of symmetry H without intersecting the axis of symmetry H, and define corresponding recesses 51 at the top and bottom, respectively, which are laterally defined by the auxiliary portion 46. Additionally, in the radial direction R, the main portion 45 of the top shielding region 40 has a greater extension than the main portion 48 of the bottom auxiliary region 42, and therefore a shorter distance from the axis of symmetry H.

[0059] In a static state, at least a portion of the main portion 45 of the top shielding area 40 is suspended above the main aperture 9, that is, it protrudes toward the axis of symmetry H relative to the lower bottom auxiliary area 42.

[0060] Without affecting any general loss, a portion of the main portion 48 of the bottom auxiliary region 42 is also suspended above the main aperture 9 along with the corresponding auxiliary portion 49, but the main portion 46 of the top shielding region 40 is further away from the axis of symmetry H than the aforementioned portion of the main portion 45 of the top shielding region 40. Without affecting any general loss, the auxiliary portion 46 of the top shielding region 40 is at least partially laterally offset relative to the main aperture 9, but variations are possible, such as, for example, the entire first shielding structure 33 being arranged on top of the main aperture 9, or, for example, as... FIG. 1B The entire bottom auxiliary area 42 shown is laterally offset relative to the main aperture 9.

[0061] In the top view, the overlap area between the main portion 45 of the top shielding area 40 and the main aperture 9 is greater than the overlap area between the main portion 48 of the bottom auxiliary area 42 and the main aperture 8. This is because, as previously stated, the radial extension of the main portion 45 of the top shielding area 40 is greater than that of the main portion 48 of the bottom auxiliary area 42.

[0062] The bottom internal structure 22 of the first semiconductor layer 14 and the top internal structure 30 of the second semiconductor layer 16 also form a corresponding deformable coupling structure 59 for each of the first and second shielding structures 33, 35. The deformable coupling structures 59 are identical to each other; for example, the following describes a structure for... FIG. 1A and FIG. 3 The deformable coupling structure 59 of the first shielding structure 33 shown.

[0063] In detail, such as FIG. 3 As shown, the deformable coupling structure 59 includes a first elastic structure M1 and a second elastic structure M2. FIG. 2 The two structures are shown in a simplified manner.

[0064] The first and second elastic structures M1 and M2 are identical and symmetrical with respect to a plane perpendicular to the plane XY and parallel to the radial direction R. Therefore, only the first elastic structure M1 is described below.

[0065] The first elastic structure M1 is an elastic conversion element of the same type as described in patent application EP3872451 filed on February 25, 2021, in the name of the applicant. Furthermore, without implying any loss in generality, the first elastic structure M1 extends at least partially within the recess 99 to reduce the overall size.

[0066] In detail, the first elastic structure M1 includes the now-referenced FIG. 3 The static state shown describes the first elongated structure L1, the second elongated structure L2 and the third elongated structure L3, the first connecting arm B1 and the second connecting arm B2, the external coupling region EC and the internal coupling region IC.

[0067] The external coupling region EC has a roughly parallelepiped shape, is formed by the bottom internal structure 22 of the first semiconductor layer 14 and the top internal structure 30 of the second semiconductor layer 16, and is fixed relative to the second end of the auxiliary portion 27B of the cantilever structure 29.

[0068] Without affecting any general loss, the first, second, and third elongated structures L1, L2, L3 are identical to each other, coplanar, and staggered in a direction parallel to the radial direction R. Therefore, the following references FIG. 4 and FIGS. 5A-5B Only the first elongated structure L2 is described.

[0069] In detail, the first elongated structure L1 includes a top elongated portion 60 formed by the top internal structure 30 of the second semiconductor layer 16 and a bottom elongated portion 62 formed by the bottom internal structure 22 of the first semiconductor layer 14.

[0070] The top elongated portion 60 and the bottom elongated portion 62 are staggered in a direction parallel to the radial direction R and have a parallelepiped shape (e.g., approximately the same shape), with their axes parallel to the transverse direction TR and arranged at different heights measured along axis Z.

[0071] Without implying any loss in generality, the top elongated portion 60 is located at a higher height than the bottom elongated portion 62; furthermore, the top elongated portion 60 and the bottom elongated portion 62 are vertically separated, that is, they do not overlap each other in the side view.

[0072] The first slender structure L1 also includes multiple transverse portions 64 (three of which are as follows) FIG. 3 As shown, without implying any loss of generality, the lateral portions are identical to each other, have a parallelepiped shape, their axes are parallel to axis Z, and are equidistant, for example, in a direction parallel to the lateral direction TR. Furthermore, lateral portions 64 are arranged between a top elongated portion 60 and a bottom elongated portion 62, which are arranged on opposite sides of each lateral portion 64. Specifically, the top portion of each lateral portion 64 laterally contacts the top elongated portion 60, while the bottom portion of the lateral portion 64 laterally contacts the bottom elongated portion 62. The top elongated portion 60, the bottom elongated portion 62, and the lateral portions 64 form a monolithic polycrystalline silicon wafer.

[0073] The first connecting arm B1 is formed by the bottom inner structure 22 of the first semiconductor layer 14 and the top inner structure 30 of the second semiconductor layer 16, and has an approximately planar shape (specifically a parallelepiped shape) parallel to the plane ZR. The first ends of the top elongated portion 60 and the bottom elongated portion 62 are fixed relative to the first connecting arm B1. The second ends of the top elongated portion 60 and the bottom elongated portion 62 are fixed relative to the outer coupling region EC. Furthermore, the top elongated portion 60 and the bottom elongated portion 62 of the second elongated structure L2 have corresponding first ends, which are fixed relative to the first connecting arm B1, thus the first connecting arm B1 is arranged between the first elongated structure L1 and the second elongated structure L2.

[0074] The second ends of the top elongated portion 60 and the bottom elongated portion 62 of the second elongated structure L2 are fixed relative to the second connecting arm B2, which has a shape that is substantially the same as that of the first connecting arm B1.

[0075] The first ends of the top elongated portion 60 and the bottom elongated portion 62 of the third elongated structure L3 are fixed relative to the inner coupling region IC, which is formed by the bottom inner structure 22 of the first semiconductor layer 14 and the top inner structure 30 of the second semiconductor layer 16. The inner coupling region IC has a generally parallelepiped shape and extends cantilevered from the corner portion of the first shielding structure 33 (e.g.,) relative to its fixed position. Specifically, the inner coupling region IC is fixed relative to portions of the top shielding region 40 and the bottom auxiliary region 42.

[0076] The second ends of the top elongated portion 60 and the bottom elongated portion 62 of the third elongated structure L3 are fixed relative to the second connecting arm B2, which is therefore arranged between the second elongated structure L2 and the third elongated structure L3.

[0077] In practice, the first elastic structure M1 has the shape of a folding spring, and its behavior is of the type described in the aforementioned patent application EP3872451 and summarized below. Furthermore, the first elastic structure M1 yields along the axis Z and the radial direction R, and is rigid in the transverse direction TR.

[0078] like FIG. 2 and FIG. 3 As shown, for each first shielding structure 33, the MEMS shielding element 1 also includes four first planar springs 69, which are now illustrated by example and reference. FIG. 3 The first shielding structure 34 shown is described therein.

[0079] In detail, the first planar spring 69 is formed by the internal moving portion 30 of the second semiconductor layer 16 and has an elongated shape. Specifically, in the stationary state, the first planar spring 69 is shaped as a parallelepiped elongated in a direction parallel to the transverse direction TR, with its first end fixed relative to the main portion 45 of the top shielding region 40 and its second end fixed relative to the corresponding first guide post region 71. For reasons to be explained below, the first planar spring 69 is rigid along the axis Z and yields in a direction parallel to the corresponding radial direction R, and more generally in a direction parallel to the plane XY.

[0080] More specifically, the first planar springs 69 are arranged in pairs on opposite sides of the main portion 45 of the top shielding region 40 in a symmetrical manner with respect to a plane of symmetry parallel to the plane RZ. Furthermore, the first guide post region 71 is formed by the first and second semiconductor layers 14, 16 (specifically by fixing portions of the bottom peripheral region 20' and the lower support region 18, and fixing portions of the top peripheral region 26'), and is anchored at the bottom to the corresponding anchoring region 8.

[0081] Regarding the second shielding structure 35, we will now use examples and references... FIG. 1A and FIG. 6 The second shielding structure 35 shown is described.

[0082] In detail, the second shielding structure 35 includes a corresponding bottom shielding region 75 formed by the bottom internal structure 22 of the first semiconductor layer 14 and a covered top auxiliary region 77 formed by the top internal structure 30 of the second semiconductor layer 16.

[0083] The bottom shielding region 75 includes a corresponding main portion 78, which has a parallelepiped shape with its axis parallel to the radial direction R associated with the second shielding structure 35, and its ends facing the axis of symmetry H and the bottom peripheral region 20, respectively. The bottom shielding region 75 also includes a corresponding auxiliary portion 79, which has a parallelepiped shape and is arranged below the end of the main portion 78 facing the axis of symmetry H. Extending below the auxiliary portion 79 is a corresponding suspended conductive region 80 made of polysilicon.

[0084] The top auxiliary region 77 includes a corresponding main portion 81 and a corresponding auxiliary portion 83. The main portion 81 has a parallelepiped shape, with its axis parallel to the radial direction R associated with the second shielding structure 35, and its ends facing the top peripheral region 26 and the axis of symmetry H, respectively. The auxiliary portion 83 has a parallelepiped shape, is arranged below the end of the main portion 81 facing the top peripheral region 26, and further directly covers the end of the main portion 78 of the bottom shielding region 75 facing the bottom peripheral region 20.

[0085] In the first approximate case, without implying any loss of generality, the main portions 78, 81 and auxiliary portions 79, 83 of the bottom shielding area 75 and the top auxiliary area 77 have the same extension in the lateral direction TR associated with the second shielding area 35.

[0086] Furthermore, the main portion 78 of the bottom shielding area 75 and the main portion 81 of the top auxiliary area 77 extend cantilevered from the auxiliary portion 83 of the top auxiliary area 76 toward the axis of symmetry H without intersecting the axis of symmetry H, and respectively define corresponding recesses 89 at the top and bottom, which are laterally defined by the auxiliary portion 83 of the top auxiliary area 77.

[0087] Additionally, in the radial direction R associated with the second shielding structure 35, the main portion 78 of the bottom shielding region 75 has a larger extension than the main portion 81 of the top auxiliary region 77, and therefore a shorter distance from the axis of symmetry H. Thus, the main portion 81 of the top auxiliary region 77 leaves the portion of the main portion 78 of the bottom shielding region 75 facing the axis of symmetry H.

[0088] More specifically, in the static state, at least a portion of the auxiliary portion 79 and the main portion 78 of the bottom shielding region 75 are suspended above the main aperture 9. Without implying any general loss, the auxiliary portion 83 of the top auxiliary region 77 is at least partially transversely staggered relative to the main aperture 9, but variations are possible, where, for example, the entire second shielding structure 35 is arranged on top of the main aperture 9, or, for example, as... FIG. 1B The entire top auxiliary area 77 shown is a laterally staggered variant relative to the main aperture 9. Furthermore, in the top view, the overlap area between the main portion 78 of the bottom shielding area 75 and the main aperture 9 is greater than the overlap area between the main portion 81 of the top auxiliary area 77 and the main aperture 8, because, as previously described, the radial extension of the main portion 78 of the bottom shielding area 75 in the radial direction R is greater than the extension of the main portion 81 of the top auxiliary area 77.

[0089] like FIG. 6 As shown, the coupling between the second shielding structure 35 and the corresponding cantilever structure 29 is achieved by inserting a corresponding deformable coupling structure 59, in the same manner as described with reference to the first shielding structure 33. Specifically, for each of the corresponding first and second elastic structures M1, M2, the corresponding internal coupling region IC extends cantilevered from (e.g.,) a corner portion of the second shielding structure 35 relative to its fixed position. Specifically, the internal coupling region IC is fixed relative to portions of the bottom shielding region 75 and the top auxiliary region 77.

[0090] For each second shielding structure 35, the MEMS shielding element 1 also includes four second planar springs 85, now illustrated by example, see reference. FIG. 6The second shielding structure 35 shown is described.

[0091] Specifically, the second planar spring 85 is formed from the bottom internal structure 22 of the first semiconductor layer 14 and has an elongated shape. Specifically, in the stationary state, the second planar spring 85 is shaped like a parallelepiped elongated in a direction perpendicular to the corresponding radial direction R, with its first end fixed relative to the main portion 78 of the bottom shielding region 75 and its second end fixed relative to the corresponding second guide post region 87. For reasons to be explained below, the second planar spring 85 is rigid along the axis Z and yields in a direction parallel to the corresponding radial direction R, and more generally in a direction parallel to the plane XY.

[0092] More specifically, the second planar springs 85 are arranged in pairs on opposite sides of the main portion 78 of the bottom shielding area 75 in a symmetrical manner with respect to a plane of symmetry parallel to the plane RZ. Furthermore, the second guide post area 87 is formed by the first semiconductor layer 14 (specifically formed by the portions of the fixed bottom peripheral area 20' and the lower support area 18) and is anchored at the bottom to the corresponding anchoring area 8.

[0093] As described above, in the static state, the top shielding area 40 of the first shielding structure 33 and the bottom shielding area 75 of the second shielding structure 35 only partially block the lower main aperture 9. Specifically, when the first and second shielding structures 33 and 35 are in a static state, maximum (partial) occlusion of the main aperture 9 is achieved; equivalently, in the static state, a minimum optical aperture occurs, which is understood as the area of ​​the main aperture 9, through which a beam of light incident normally onto the MEMS shielding member 1 can pass. Furthermore, each actuator 36 can be operated to move the corresponding first / second shielding structure 33 / 35 in a direction opposite to the axis of symmetry H along the corresponding radial direction R, thereby reducing the occulus of the lower main aperture 9, as described below. FIG. 3 The same considerations as those described in detail for the first shielding structure 33 also apply to the second shielding structure 35.

[0094] like FIG. 7 As shown, actuator 36 can be operated to cause translation of the corresponding cantilever structure 29 along axis Z, thereby also causing translation of the outer coupling region EC, which pulls the fixed portions of the first and second elastic structures M1 and M2 upward. Since the portions of the first and second elastic structures M1 and M2 fixed relative to the first shielding structure 33 via the inner coupling region IC cannot translate along axis Z due to the constraint applied by the first planar spring 69, the deformable coupling structure 59 undergoes a process as described above. FIG. 7 The deformation is shown qualitatively.

[0095] In detail, the behavior of the first and second elastic structures M1, M2 is the same as that described in the aforementioned patent application EP3872451. Specifically, for example, referring to the first elastic structure M1 and further referring to, for example, the first elongated structure L1, each portion of the first elongated structure L1, taken in a plane parallel to the plane ZR, has a pair of principal axes of inertia I1, I2 (e.g., FIG. 5A and FIG. 5B As shown, for reference FIG. 4 Each principal axis of inertia is transverse relative to the radial direction R and the axis Z. Therefore, the force applied to the first elongated structure L1 along the axis Z generates a so-called deflection flexure of the first elongated structure L1; specifically, the force causes deformation along the axis Z, which results in subsequent deformation of the first elongated structure L1 in the corresponding radial direction R.

[0096] In practice, although the portions of the first and second elastic structures M1 and M2 fixed relative to the outer coupling region EC are translated along the axis Z to a first approximate value, no movement occurs in the plane XY. The portions of the first and third elastic structures M1 and M2 fixed relative to the inner coupling region IC are not translated along the axis Z, but are translated along the corresponding radial direction R in the direction opposite to the axis of symmetry H, dragging the first shielding structure 33 and reducing the overlap area between the first shielding structure and the lower main aperture 9. Due to this dragging action, the first planar spring 69 bends in the top view.

[0097] As the first and second shielding structures 33, 35 move away from the axis of symmetry H, the shading of the main aperture 9 decreases. Furthermore, since each first shielding structure 33 is arranged at an angle between a pair of second shielding structures 35, and vice versa, and since the top shielding region 40 and the bottom shielding region 75 are formed by the second semiconductor layer 16 and the first semiconductor layer 14, respectively, and are therefore arranged at different levels, the movement of each shielding structure can be carried out independently of the movement of adjacent shielding structures without affecting or restricting the movement. In this respect, as... FIG. 2 As shown, without implying any general loss, in the static state, the end of the main portion 45 of each top shielding area 40 facing the axis of symmetry H covers the end portions of the main portions 78 of two adjacent bottom shielding areas 75 facing the axis of symmetry H.

[0098] In practice, the control of the main aperture 9 is performed on the entire periphery of the main aperture 9 with a large number of degrees of freedom.

[0099] according to FIG. 8The variant shown (the main aperture 9 is not shown for simplicity) has first and second shielding structures 33 and 35 of the same type as the aforementioned shielding structures, the same arrangement in the static state, and the same ability to translate in the corresponding radial direction R; however, the actuator (indicated by 96) is electrostatic. Reference is now made only by way of example. FIG. 9 The variant is described using the actuator 96 coupled to the first shielding structure 33, but the description also applies to the actuator 96 coupled to the second shielding structure 35.

[0100] In detail, the actuator 96 is electrostatic and includes, for example, a pair of first stator regions ST1 and a pair of second stator regions ST2, which are formed by corresponding portions of the fixed peripheral structure 28 (i.e., by corresponding portions of the fixed bottom peripheral region 20' and the fixed top peripheral region 26') as well as the lower support region 18 and the lower anchoring region 8. The first and second stator regions ST1, ST2 are thus fixed relative to the lower substrate 2.

[0101] In addition, the first shielding structure 33 is operatively coupled to the actuator 96 by means of a coupler 100, which is generally T-shaped in top view.

[0102] Specifically, such as FIG. 10 As shown, the coupler 100 is formed by the bottom internal structure 22 of the first semiconductor layer 14 and the top internal structure 30 of the second semiconductor layer 16. Furthermore, the coupler includes: an elongated portion 102 in the shape of a parallelepiped, extending in a direction parallel to the radial direction R; and a lateral portion 104, which further includes a support portion 105 and a plurality of coupling portions 106. The support portion 105 has a shape that elongates in a direction parallel to the lateral direction TR. The plurality of coupling portions 106 are arranged on two opposite sides of the support portion 105 and staggered in the lateral direction TR. Each coupling portion 106 is located away from a corresponding side of the support portion 105 in a direction parallel to the radial direction R.

[0103] The elongated portion 102 has a first end fixed relative to the first shielding structure 33 and a second end fixed relative to the support portion 105 of the transverse portion 104, which together with the coupling portion 106 serves as a rotor region.

[0104] The first and second stator regions ST1 and ST2 extend on opposite sides of the transverse portion 104 and form corresponding plurality of elements (denoted by 107 and 108, respectively) elongating in the radial direction R. The elongated elements 107 of each first stator region ST1 are laterally staggered in a direction parallel to the transverse direction TR, interlacing with the corresponding set of the coupling portion 106. Similarly, the elongated elements 108 of each second stator region ST2 are laterally staggered in a direction parallel to the transverse direction TR, interlacing with the corresponding set of the coupling portion 106.

[0105] Two pairs of third guide post regions 171 extend on opposite sides of the elongated portion 102 of the coupler 100 and have the same structure as the first guide post region 71, and are thus anchored at the bottom to the corresponding anchoring region 8. Each third guide post portion 171 is mechanically coupled to the elongated portion 102 of the coupler 100 by inserting a corresponding third planar spring 169, which has, for example, a folded shape, formed by the bottom inner structure 22 of the first semiconductor layer 14 and the top inner structure 30 of the second semiconductor layer 16, and is rigid along the axis Z and yields in a direction parallel to the corresponding radial direction R, and more generally in a direction parallel to the plane XY.

[0106] In practice, the first shielding structure 33 and the coupler 100 are suspended and constrained to the third guide post area 171 by inserting the third planar spring 169. Although not shown, a variation may also exist in which the end of the third planar spring 169 is fixed to the first shielding structure 32 instead of to the coupler 100.

[0107] In use, by applying a voltage between the first and second stator regions ST1, ST2 and the rotor region, the coupler 100 is subjected to electrostatic forces, which causes the coupler 100 to translate relative to the first and second stator regions ST2 in the corresponding radial direction R; the translation can be performed in either direction. The first shielding structure 33 is translated in the corresponding radial direction R in a fixed manner relative to the coupler 100, thereby changing the shielding of the lower main aperture 9.

[0108] Therefore, the advantages provided by arranging the first shielding structure 33 and the second shielding structure 35 to form a shield in different semiconductor layers are also obtained in this variant. Furthermore, according to this variant, the shielding structure can undergo positive and negative displacements relative to the corresponding radial direction R relative to its assumed position in a static state.

[0109] For reference FIG. 11 As shown, when using a piezoelectric actuator, both positive and negative displacements relative to the stationary position can be obtained. Now, only [the following is discussed]. FIG. 3 The differences shown are described.

[0110] In detail, the cantilever structure (represented here by 229) includes an auxiliary portion 27B, which is coupled to the corresponding shielding structure in the same manner as described above; in this respect, FIG. 11 In the example, refer to the first shielding structure 33.

[0111] The main portion of the cantilever structure 229 (represented here by 227A) has a folded shape to define a C-shape in the top view; specifically, the main portion 227A includes a first elongated sub-portion 228A, a second elongated sub-portion 228B, and a connecting sub-portion 228. For example, the first elongated sub-portion 228A has a... FIGS. 2-3 The main portion 27A of the cantilever structure 29 shown has the same shape. In addition, the second elongated sub-portion 228B has a parallelepiped shape, for example, elongated in a direction parallel to the corresponding transverse direction TR; the first and second elongated sub-portions 228A and 228B are staggered in the radial direction R and connected by the connecting sub-portion 228.

[0112] More specifically, the end of the first elongated sub-part 228A opposite to the deformable coupling structure 59 is fixed relative to the connecting sub-part 228. The first end and the second end of the second elongated sub-part 228B are fixed relative to the fixed peripheral structure 28 and the connecting sub-part 228, respectively.

[0113] Additionally, the first elongated sub-part 228A is derived from the reference. FIG. 1A and FIG. 3 The first actuator (represented here by 236') of the same type as the described actuator is covered, while the second elongated sub-section 228B is covered by the reference. FIG. 1A and FIG. 3 A corresponding second actuator (represented here by 236") of the same type is covered, and the second actuator is electrically decoupled from the first actuator 236'. In this way, by alternately supplying voltage to the first actuator 236' or the second actuator 236", the auxiliary part 27B translates in the opposite direction along the axis Z, and the corresponding shielding structure translates in the opposite direction accordingly.

[0114] Regardless of the type of embodiment, the first and second shielding structures (although arranged at alternating angles) may also have, for example... FIG. 12 The shapes and / or arrangements shown differ from those described, wherein the first and second shielding structures are represented by 333 and 335, respectively, and wherein piezoelectric actuation is assumed only as an example, but variations of electrostatic actuation (not shown) may also be used in this case. Therefore, the following description is limited to those... FIG. 1A Differences in the descriptions of the illustrated embodiments. Unless otherwise specified, FIG. 1A Elements already present in the illustrated embodiments are indicated by the same reference numerals. Furthermore, in FIG. 12The deformable coupling structure 59 is illustrated in a simplified manner in the following figures. Similarly, FIG. 12 The first end of the main portion 27A of the cantilever structure 29 (not shown) is fixed relative to the corresponding portion of the fixed peripheral structure 28. FIG. 12 (Not shown in the image). Additionally, for simplicity, FIG. 12 The coupling between the first and second shielding structures 333, 335 and the coupling between the first and third guide post regions via the first and second planar springs are not shown. Finally, in the following text, the terms "far end" and "proximal end" are used to indicate the shielding structure portions arranged away from or near the corresponding deformable coupling structure 59, respectively.

[0115] As described above, each of the first shielding structure 333 and the second shielding structure 335 extends in a direction parallel to the corresponding extension direction (represented by R', respectively). Specifically, in the stationary state, the first and second shielding structures 333 and 335 have the same mutual arrangement relative to the corresponding extension direction R'.

[0116] The extension direction R', parallel to the plane XY, is coplanar with and equidistant from the axis of symmetry H; in other words, in the top view and at rest, the extension direction R' reaches a first approximation of being tangent to an imaginary circle (not shown) centered on the axis of symmetry H. Furthermore, adjacent extension directions form an angle of 45° with respect to R', thus forming an angular distribution over 360°.

[0117] For each shielding structure, the corresponding cantilever structure 29, the corresponding deformable coupling structure 59, and the corresponding actuator 36 have the same characteristics as... FIG. 1A The embodiments shown have the same shape and arrangement as described above, except that they refer to the corresponding extension direction R' instead of the radial direction R mentioned above.

[0118] Now for reference FIG. 13A and FIG. 13B The first shielding structure 333 shown describes the shape of the first shielding structures 333 that are identical to each other; in addition, the "lateral direction" (represented by TR') is the direction perpendicular to the plane ZR'.

[0119] In detail, the main part of the top shielding area (represented by 340) (represented by 345) gradually tapers in a direction parallel to the extension direction R', that is, its extension in the lateral direction TR' decreases as the distance from the corresponding deformable coupling structure 59 increases.

[0120] In the top view, the main portion (represented by 348) of the bottom auxiliary area (represented by 342) has a roughly wedge shape and, except that it has a smaller maximum dimension than the maximum dimension of the main portion 345 of the top shielding area 340 in the direction parallel to the extension direction R', it also tapers gradually in the direction parallel to the extension direction R'. Furthermore, the maximum extension of the main portion 348 of the bottom auxiliary area 342 in the direction parallel to the lateral direction TR' is less than the maximum extension of the main portion 340 of the top shielding area 340 in the same direction.

[0121] The second portion (denoted by 346) of the top shielding region 340 has a shape in the top view that is substantially the same as the main portion 348 of the bottom auxiliary region 342, except for a recess. In other words, without implying any loss of generality, the auxiliary portion 346 covers the proximal portion of the main portion 348 of the bottom auxiliary region 342, leaving the distal portion of the main portion 348 of the bottom auxiliary region 342 exposed.

[0122] The auxiliary portion of the bottom auxiliary area 342 and the lower suspended conductive area are represented by 349 and 350, respectively.

[0123] More specifically, for reasons explained below, the main portion 345 of the top shielding region 340 extends cantileveredly from the auxiliary portion 346 of the top shielding region 34, protruding beyond the main portion 338 of the bottom auxiliary region 342 not only in a direction parallel to the extension direction R', but also in a direction parallel to the lateral direction TR'. In other words, both the distal and proximal portions of the main portion 345 of the top shielding region 340 (hereinafter referred to as the protruding proximal portion of the main portion 344) are suspended and laterally protruding relative to the lower bottom auxiliary region 342.

[0124] The main portion 340 and auxiliary portion 346 of the top shielding area 340, and the main portion 348 of the bottom auxiliary area 342, form a coupling wall 398 perpendicular to the extending direction R'. Without implying any loss in generality, the first and second elastic structures M1 and M2 of the corresponding deformable coupling structure 59 are fixed relative to the respective portions of the coupling wall 398.

[0125] Regarding the identical second shielding structure 335, now refer to FIG. 14A and FIG. 14B The shape is described by the second shielding structure 335 shown.

[0126] In detail, the main portion (represented by 378) of the bottom shielding area (represented by 375) has a shape that is substantially the same as the main portion 345 of the top shielding area 340, and is perpendicularly intersected with respect to the top shielding area 345.

[0127] The main portion (represented by 381) and auxiliary portion (represented by 373) of the top auxiliary region (represented by 377) have a wedge shape that is substantially the same as that of the main portion 348 of the bottom auxiliary region 342 and the auxiliary portion 346 of the top shielding region 340. Therefore, the main portion 381 of the top auxiliary region 377 completely covers the auxiliary portion 383, but leaves the exposed distal and proximal portions (hereinafter referred to as the exposed proximal portions) of the main portion 378 of the bottom shielding region 375 protruding in the extension direction R' and the lateral direction TR', respectively.

[0128] The auxiliary part of the bottom shielding area 375 and the lower suspended conductive area are represented by 379 and 380, respectively.

[0129] The main portion 381 and auxiliary portion 383 of the top auxiliary area 377 and the main portion 378 of the bottom shielding area 375 form a coupling wall 399 perpendicular to the extension direction R'. Without implying any loss in generality, the first and second elastic structures M1 and M2 of the corresponding deformable coupling structure 59 are fixed relative to the respective portions of the coupling wall 399.

[0130] Due to the geometry of the first and second shielding structures 333 and 335, the following situation will occur when they are at rest.

[0131] In detail, considering any first shielding structure 333, the distal portion of the main portion 345 of the corresponding top shielding area 340 covers the proximal portion of the main portion 378 of the bottom shielding area 375 of the second shielding structure 335 at a certain distance, the second shielding structure 335 being adjacent to the shielding structure 332 and arranged in a counterclockwise direction.

[0132] Additionally, the protruding proximal portion of the main portion 345 of the top shielding area 340 covers the distal portion of the main portion 378 of the bottom shielding area 375 of the second shielding structure 335 at a certain distance, the second shielding structure 335 being adjacent to the shielding structure 333 and arranged in a clockwise direction.

[0133] Furthermore, the first shielding structure 333 and the second shielding structure 335 can be translated in the corresponding extension direction R' in the same manner as described in the previous embodiments to reduce the overlap area between the shielding structures, thereby reducing the lower main aperture 9( FIG. 12 Obstruction (not shown in the image).

[0134] According to another variant, such as FIG. 15 As shown, the MEMS shielding element 1 may not have a second shielding structure, where the first shielding structure is represented by 433. Furthermore, in FIG. 15In the diagram, the main aperture 9 is not shown. For simplicity, the coupling between the first shielding structure 433 and the corresponding guide post area is also not shown. This coupling is provided by a corresponding planar spring of the same type as described above and is formed indistinguishably by the first semiconductor layer 14 and / or the second semiconductor layer 16.

[0135] As described above, MEMS shielding component 1 and FIG. 12 The difference shown is that it includes eight first shielding structures 433, which are identical to each other and spaced apart by equal angular distances (in the stationary state).

[0136] like FIGS. 16A-16B As shown, each first shielding structure 433 includes a corresponding top shielding region 440 formed by the top internal structure 30 of the second semiconductor layer 16 and a corresponding bottom shielding region 442 formed by the bottom internal structure 22 of the first semiconductor layer 14.

[0137] The top shielding area 440 includes a corresponding auxiliary portion 446 and a corresponding main portion 481; the bottom shielding area 442 includes a corresponding main portion 448 and a corresponding auxiliary portion 479. The lower suspended conductive area is represented by 480.

[0138] The proximal portion 481' of the main portion 481 and the auxiliary portion 446 of the top shielding region 440 together with the first portion 448' of the main portion 448 of the bottom shielding region 442 form the main body 499; the first elastic structure M1 and the second elastic structure M2 of the deformable coupling structure 59 are fixed relative to the main body 499.

[0139] The distal portion 481” of the main portion 481 of the top shielding area 440 extends from the main body 499 in a cantilever manner, generally along the corresponding extension direction R', protruding relative to the lower bottom shielding area 442.

[0140] The second part 448” of the main part 448 of the bottom shielding area 442 is covered by the exposed top shielding area 440 and is laterally staggered relative to the main body 499.

[0141] Due to the aforementioned shape of the first shielding structure 433, in a static state, such as FIG. 15As shown, the distal portion 481” of the main portion 481 of the top shielding area 440 of any first shielding structure 430 covers the second portion 448” of the main portion 448 of the bottom shielding area 442 of the first shielding structure arranged counterclockwise at a certain distance. Furthermore, the second portion 448” of the main portion 448 of the bottom shielding area 442 of any first shielding structure 433 is covered by the distal portion 481” of the main portion 481 of the top shielding area 440 of the first shielding structure arranged clockwise at a certain distance. Under these conditions, since there is no continuous solution between the first shielding structures in the top view, the shading of the lower main aperture 9 is maximized.

[0142] The first shielding structure 433 can be translated in the corresponding extension direction R', so that the distal portion 481” of the main portion 481 of the top shielding area 440 is laterally separated from the adjacent shielding structure, that is, they no longer overlap. In other words, in the top view, there is a solution to the continuity between the first shielding structures 433; that is, the shading of the lower main aperture 9 is reduced.

[0143] Although not shown, the following variations are possible: the type of MEMS shielding element 1 and... FIG. 12 or FIG. 15 The types shown are the same, but piezoelectric actuation is as follows: FIG. 11 The bidirectional type shown is either electrostatic or in the case of a shielding structure coupled to the corresponding coupler. For example, see reference... FIG. 12 , FIGS. 13A-13B and FIGS. 14A-14B In the variant shown, in the case of the first shielding structure 333, the coupler can be fixed relative to the aforementioned coupling wall 398, and in the case of the second shielding structure 335, it can be fixed relative to the aforementioned coupling wall 399.

[0144] This MEMS shielding element 1 can use the following reference. FIG. 1A The process described in the illustrated embodiment is used for manufacturing.

[0145] like FIG. 17 As shown, the process was originally envisioned to form a first dielectric layer 504 and a second dielectric layer 516 on the substrate 2 of the semiconductor wafer 500; the first and second dielectric layers 504 and 506 are made of thermal oxide and aluminum oxide, respectively.

[0146] Next, as FIG. 18 As shown, a portion of the second dielectric layer 506 is selectively removed to form a first preparatory opening WP1 through the second dielectric layer 506, thereby exposing a portion of the first dielectric layer 404.

[0147] Then, as FIG. 19As shown, portions of the exposed portion of the first dielectric layer 504 are selectively removed to form a second pre-opening WP2 and a third pre-opening WP3 through the first dielectric layer 504. The third pre-opening WP3 is shaped like a trench and surrounds the second pre-opening WP2 at a certain distance in the lateral direction.

[0148] Next, as FIG. 20 As shown, polysilicon is deposited and then selectively etched, such that the remaining polysilicon forms a conductive layer 7 within the third pre-opening WP3, as well as an anchoring region 8 and an intermediate conductive region 510. The intermediate conductive region 510 extends in the second pre-opening WP2, contacts the substrate 2, and extends over portions of the first dielectric layer 504 that laterally define the second pre-opening WP2. The conductive layer 7 and the intermediate conductive region 510 are laterally separated from each other; therefore, the polysilicon deposition and subsequent etching operations leave exposed portions of the first dielectric layer 504, which are laterally staggered relative to the conductive layer 7 and the intermediate conductive region 510. Furthermore, a second semiconductor layer 506 is disposed outside the conductive layer 7 and remains exposed relative to the laterally staggered portions of the anchoring region 8.

[0149] Next, as FIG. 21 As shown, the first sacrificial region 515 is formed on the exposed portions of the conductive layer 7, the anchoring region 8, the intermediate conductive region 510, and the first and second dielectric layers 504 and 506, and then planarized (the steps are not shown in detail). Specifically, the first sacrificial region 515 is made of TEOS oxide deposited by chemical vapor deposition.

[0150] Then, as FIG. 22 As shown, etching is performed to selectively remove portions of the first sacrificial region 515 disposed on the anchoring region 8 and the intermediate conductive region 510. Specifically, a corresponding fourth pre-opening WP4 is formed, which passes through the first sacrificial region 515 and extends into the exposed interior portion of the intermediate conductive region 510. Without implying any general loss, in addition to the portion of the intermediate conductive region 510 in contact with the substrate 2, this interior portion of the intermediate conductive region 512 also includes the portion of the intermediate conductive region 520 extending on the first dielectric layer 504. Furthermore, a fifth pre-opening WP5 is formed, which passes through the first sacrificial region 515 and extends into the corresponding anchoring region 8.

[0151] Next, as FIG. 23As shown, a first epitaxial growth of silicon is performed to form and planarize a first semiconductor layer 14 (steps not shown in detail). As previously described, the first semiconductor layer is made of polycrystalline silicon and extends over a first sacrificial region 515 and within a fourth pre-opening WP4, directly contacting the intermediate conductive region 510 and directly contacting the anchoring region 8 within a fifth pre-opening WP5. Specifically, the portion of the first semiconductor layer 14 extending into the fifth pre-opening WP5 forms the aforementioned support region 18, i.e., the anchoring of the first semiconductor layer.

[0152] like FIG. 24 As shown, using a mask (not shown), the portion of the first semiconductor layer 14 that is laterally intersected with the anchoring region 8 and the intermediate conductive region 510 is then selectively removed to form a plurality of first process openings 520 that pass through the first semiconductor layer 14 and are defined at the bottom by corresponding portions of the first sacrificial region 515.

[0153] The first process opening 520 laterally defines the first semiconductor layer 14 forming the bottom peripheral region 20 and the various parts of the deformable coupling structure 59 (specifically, the bottom elongated portion 62 of the elongated structure of the elastic structure).

[0154] Next, as FIG. 25 As shown, the second sacrificial region 525 is formed by chemical vapor deposition. The second sacrificial region 525 is formed of TEOS oxide and extends on the first semiconductor layer 14 and within the first process opening 520 until it contacts the portions of the first sacrificial region 515 that define the first process opening 520 at the bottom.

[0155] Then, as FIG. 26 As shown, selective etching is performed to remove portions of the second sacrificial region 525 disposed on the first semiconductor layer 14, thereby laterally interleaving it relative to the first process opening 520. Specifically, an anchoring opening 527 is formed, which is defined at the bottom by the corresponding portion of the first semiconductor layer 14.

[0156] Next, as FIG. 27 As shown, a second epitaxial growth of silicon is performed to form a second semiconductor layer 16, which is then planarized (steps not shown in detail). As previously described, the second semiconductor layer 16 is made of polycrystalline silicon and extends over the second sacrificial region 525 and within the anchoring opening 527 to contact portions of the first semiconductor layer 14 that define the anchoring opening 517 at the bottom. Except for the auxiliary portion 46 of the top shielding region 40 of the first shielding structure 33 and the auxiliary portion 83 of the top auxiliary region 77 of the second shielding structure 35, the portions of the second semiconductor layer 16 that contact the first semiconductor layer 16 will form a top peripheral region 26 and a portion of the deformable coupling structure 59 (specifically, a portion of the lateral portion 64 of the elongated structure of the elastic structure).

[0157] Then, as FIG. 28 As shown, actuator 36 is formed in a manner known per se.

[0158] Next, as FIG. 29 As shown, selective etching is performed using a mask (not shown) to remove portions of the second semiconductor layer 16 and form a second process opening 530 that traverses the second semiconductor layer 16 and is defined at the bottom by a corresponding portion of the second sacrificial region 525.

[0159] In practice, the second process opening 530 laterally defines the top peripheral region 26 and the top elongated portion 60 of the elongated structure forming the elastic structure of the second semiconductor layer 16. Furthermore, the second process opening 530 laterally defines the main portion 45 of the top shielding region 40 of the first shielding structure 33 and the main portion 81 of the top auxiliary region 77 of the second shielding structure 35.

[0160] Next, as FIG. 30 As shown, on the semiconductor wafer 500, a protective layer 540 is formed, for example, by depositing TEOS oxide. The protective layer 540 extends over the protective zone 34 of the actuator 36, over the exposed portion of the second semiconductor layer 16, and within the second process opening 530 until it contacts the portions of the second sacrificial region 525 that define the second process opening 530 at the bottom.

[0161] Then, as FIG. 31 As shown, using a corresponding mask (not shown), back-side etching is performed on substrate 2 to selectively remove portions of substrate 2 that are arranged below the intermediate conductive region 510 and form the main aperture 9.

[0162] Specifically, the etching is dry etching (e.g., using sulfur hexafluoride), and since etching cannot remove all portions of the first dielectric layer 504, it is guided by the portion of the intermediate conductive region 510 that contacts the substrate 2 and the aforementioned mask. Therefore, except for the aforementioned portion of the intermediate conductive region 510 that contacts the substrate 2, the overlapping portion of the first semiconductor layer 14 is selectively removed. In this way, an intermediate opening 550 is formed, extending through the first semiconductor layer 14 and the first dielectric layer 504 and communicating with the underlying main aperture 9.

[0163] At each of the first shielding structures 33, the central opening 550 is covered by a portion of the second sacrificial region 525 arranged below the main portion 45 of the corresponding top shielding region 40; in fact, this portion of the second sacrificial region 525 is able to achieve local etch stop before the main portion 45 is damaged.

[0164] Furthermore, the etching mask removes the laterally staggered portions of the substrate 2 relative to the covered intermediate conductive region 510, which are defined at the top by corresponding portions of the first dielectric layer 504. In this way, the main aperture 9 is partially closed at the top by these portions of the first dielectric layer 504, which are laterally staggered relative to the portion of the intermediate conductive region 510 that contacts the substrate 2. These portions of the first dielectric layer 504 are then laterally surrounded by the conductive layer 7. In practice, these portions of the first dielectric layer 504 partially close the top opening of the main aperture 9 (understood as the main aperture 9 on the top surface S of the substrate 2). a (area in the plane).

[0165] Specifically, for each second shielding structure 35, the main aperture 9 is partially shielded by a corresponding portion of the first dielectric layer 504, and this corresponding portion is covered by a corresponding portion of the first sacrificial region 515 arranged below the main portion 78 of the corresponding bottom shielding region 75. The aforementioned corresponding portion of the first dielectric layer 504 prevents etching of the corresponding bottom shielding region 75.

[0166] exist FIG. 31 When the operation shown is completed, the remaining portion of the first semiconductor layer 14 forms the bottom auxiliary region 42 of the first shielding structure 33 and the bottom shielding region 75 of the second shielding structure 35. The remaining portion of the intermediate conductive region 510 constitutes the suspended conductive regions 50, 80. In this respect, in FIG. 31 In the diagram, it can be noted how the suspended conductive regions 50 and 80 protrude slightly outward relative to the corresponding auxiliary portions 49 and 79; this detail is irrelevant to the operational purpose of the MEMS shielding element 1 and is not shown in other figures for simplicity. Furthermore, the degree of projection can be greater than... FIG. 31 The value shown is much smaller (virtually negligible).

[0167] Next, etching is performed using hydrofluoric acid, which allows the removal of the contacting protected areas 540, as well as the first sacrificial area 515 and the second sacrificial area 525. Furthermore, the portion of the first dielectric layer 504 that partially closes the main aperture 9 at its top is removed. These portions of the first dielectric layer 504 are removed because they are not protected by the alumina of the second dielectric layer 506. Thus, the first and second shielding structures 33, 35, along with the corresponding cantilever structure 29 and the corresponding deformable coupling structure 59, are released, thereby obtaining… FIG. 1A The effect shown. The remaining portions of the first and second dielectric layers 504 and 506 form the first and second dielectric regions 4 and 6, respectively.

[0168] Typically, the described manufacturing process can also be used to manufacture other embodiments, such as embodiments with electrostatic actuation. In this regard, see reference, for example. FIGS. 8-10In the illustrated embodiment, the formation of the first and second shielding structures 33, 35 is performed in the same manner as described above. Additionally, the formation of the first sacrificial region 515 and the subsequent formation of the first process opening 520 through the first semiconductor layer 14 define, in addition to the portions of the first and second stator regions ST1, ST2 formed by the first semiconductor layer 14, the third planar spring 169 and portions of the coupler 100 formed by the first semiconductor layer 14. The formation of the second process opening 530 through the second semiconductor layer 16 defines, in addition to the portions of the first and second stator regions ST1, ST2 formed by the second semiconductor layer 16, portions of the third planar spring 169 and portions of the coupler 100 formed by the second conductor layer 16.

[0169] Other possible variations are, for example, such as FIG. 32 As shown in the previous reference FIG. 24 The etching of the first semiconductor layer 14 and the formation of the first process opening 520 do not require defining (e.g.,) the bottom peripheral region 20. In this case, the bottom peripheral region 20 can be defined during a subsequent etching of the second semiconductor layer 16, which is performed to remove the lower portion of the first semiconductor layer 14. For this purpose, as FIG. 33 As shown in the previous reference FIG. 26 The patterning of the second sacrificial region 525 and the mask used during the selective etching of the second semiconductor layer 16 (see reference). FIG. 29 (Not shown and mentioned) such that the subsequent etching not only forms the second process opening 530, but also a deep opening 530*, which passes through the first semiconductor layer 14 and the second semiconductor layer 16 and is defined at the bottom by the first sacrificial region 515. Furthermore, although not shown, in the case of a variation where the etching of the second semiconductor layer 16 also includes removing the lower portion of the first semiconductor layer 14 until portions of the first sacrificial region 515 are exposed, the protective layer 540 may extend within the deep opening 530* until it contacts the aforementioned portion of the first sacrificial region 505. Additionally, the deep opening 530* can generally be used to define portions of the MEMS shielding member 1 formed by the first semiconductor layer 14 and the second semiconductor layer 16, such as the aforementioned lateral portion 64.

[0170] The advantages offered by this solution are clearly evident from the preceding description.

[0171] Specifically, this MEMS shielding element 1 can be electrically controlled to change the optical aperture with a large number of degrees of freedom. In fact, a large portion of the outer portion of the main aperture 9 can be selectively shielded by translating the corresponding shielding structure. The fact that the shielding structure is patterned at two different levels allows for optimization of the angular arrangement of the shielding structure itself. In this respect, the effect of the movement of the shielding structure on the optical aperture is generally also related to the profile of the lower main aperture 9, which represents the further degrees of freedom available to the designer.

[0172] Finally, it is obvious that modifications and variations can be made to the manufacturing processes and MEMS shielding elements described and illustrated herein without departing from the scope of this disclosure as defined by the appended claims.

[0173] For example, the shapes of the shielding structure, the fixed peripheral structure, the cantilever structure, the deformable coupling structure (in the case of piezoelectric actuation), and the coupler and stator region (in the case of electrostatic actuation) may differ from those already described. For example, the stator region may further include a cantilever portion.

[0174] Furthermore, for example, due to the typical tolerances of etching processes, such as FIG. 27 The tolerances that result in the formation of anchorage opening 527 shown may differ from those described during the manufacturing process due to variations in the alignment of different areas. Therefore, for example, it is possible to obtain... FIG. 34 The results shown FIG. 34 The steps of the manufacturing process and FIG. 31 The steps shown are the same.

[0175] In detail, if the top surface S top The top surface designated as the second sacrificial region 525, the top peripheral region 26 and the top internal structure 30 (formed by the second semiconductor layer 16) are located on the top surface S. top The parts above are from the top surface S top and the surface that geometrically separates the first and second semiconductor layers 14, 16 (by S) int The corresponding lower part between (indicated) protrudes slightly.

[0176] Referring again to the manufacturing process, the polycrystalline silicon forming the first and second semiconductor layers 14, 16 can be formed in a manner known per se, for example by epitaxial growth starting from the substrate 2 and the exposed portion (not shown) of the first semiconductor layer 14, respectively, to accelerate their growth and increase the thickness of the first and second semiconductor layers 14, 16. In this regard, typically, both the first semiconductor layer 14 and the second layer 16 can have a thickness, for example, between 1 μm and 80 μm.

[0177] The second dielectric layer 506 and therefore the second dielectric region 6 can also be made of a hydrofluoric acid resistant material (e.g., silicon nitride) that is different from alumina.

[0178] The number, shape, and arrangement of the guide post area and the planar spring can differ from those described. Similarly, the points where the shielding structure or coupler is used to fix the planar spring can also vary.

[0179] Finally, the first shielding structure may be formed only by the corresponding portion of the second semiconductor layer 16 and / or the second shielding structure may be formed only by the corresponding portion of the first semiconductor layer 14, for example, as shown in the figure. FIG. 35 As shown, each first shielding structure 33 is formed by the main portion 45 of the top shielding area 40; in addition, each second shielding structure 45 is formed by the bottom shielding area 75.

[0180] Similarly, the coupler 100 and the deformable coupling structure 59 may also be formed from portions of one of the first semiconductor layer 14 and the second semiconductor layer 16; in addition, the cantilever structure 29 may be formed from the second semiconductor layer 16 alone.

[0181] Finally, the presence of conductive layer 7 is optional.

[0182] MEMS masking can be summarized as including: a semiconductor material substrate (2) through which a main aperture (9) passes; a first semiconductor layer (14) disposed on top of the substrate (2); a second semiconductor layer (16) disposed on top of the first semiconductor layer (14) and forming a support structure (28, 71, 87; 28, 171) together with the first semiconductor layer (14) to be fixed to the substrate (2); a plurality of deformable structures (29, 59, 68, 85; 169), each deformable structure being formed by a corresponding portion of at least one of the first and second semiconductor layers; a plurality of actuators (36; 96); and a plurality of shielding structures (3 3; 35; 333; 335; 433), each shielding structure is formed by a corresponding portion of at least one of the first and second semiconductor layers, the shielding structures are arranged at an angle around the lower master aperture to form a shield of the master aperture, each shielding structure is further mechanically coupled to the support structure via a corresponding deformable structure; and wherein each actuator is electrically controllable to cause the corresponding shielding structure to translate between a corresponding first position and a corresponding second position, thereby changing the shield of the master aperture; and wherein the first and second positions of the shielding structures are such that, in at least one operating state of the MEMS shielding member (1), adjacent shielding structures at least partially overlap each other.

[0183] The plurality of shielding structures (33; 35; 333; 335; 433) may include a plurality of first shielding structures (32; 333) and a plurality of second shielding structures (35; 335) arranged at alternating angles. Each first shielding structure may include a corresponding top structure (40; 340) formed by a second semiconductor layer (16), and each second shielding structure may include a corresponding bottom structure (75; 375) formed by a first semiconductor layer (14). The top structure of each first shielding structure partially overlaps with the bottom structure of the adjacent second shielding structure when the MEMS shielding member (1) can be in the at least one operating state.

[0184] Each first shielding structure (33; 333) may further include a corresponding bottom structure (42; 342) formed by a first semiconductor layer (14), and a corresponding top structure (40; 340) may include at least one protrusion (45; 345) that protrudes laterally relative to the corresponding bottom structure (42; 332); and each second shielding structure (35; 335) may include a corresponding top structure (77; 377) that may be formed by a second semiconductor layer (16) and leaves an exposed portion (78; 378) of the corresponding bottom structure (75; 375); and when the MEMS shielding member (1) is in the at least one operating state, the protrusion of the top structure of each first shielding structure may at least partially cover the exposed portion of the bottom structure of the adjacent second shielding structure.

[0185] When the MEMS shielding member (1) is in at least one of the operating states, the protruding portion (45; 345) of the top structure (40; 340) of the first shielding structure (33; 333) and the exposed portion (78; 378) of the bottom structure (75; 375) of the second shielding area (35; 335) can at least partially cover the main aperture (9).

[0186] Each first shielding structure (33; 333) may include a top structure (40; 340) fixed relative to a corresponding lower bottom structure (42; 342) and a top main portion (45, 345) extending cantilevered relative to the top auxiliary portion and forming the protruding portion (45; 345); and each second shielding structure (35; 335) may include a bottom main portion (78; 378) fixed relative to a corresponding covered top structure (77; 377) and forming the exposed portion of the bottom structure.

[0187] The top main portion (45; 345) and the bottom main portion (78; 378) can extend parallel to the corresponding direction (R; R'); and each actuator (36; 96) can be electrically controlled to translate the corresponding first shielding structure (33; 333) or the corresponding second shielding structure (35; 335) parallel to the corresponding direction.

[0188] The direction (R) can be a radial direction.

[0189] The direction (R') can be coplanar and equidistant from the axis of symmetry (H) of the main aperture (9).

[0190] Each shielding structure (433) may include a corresponding top structure (440) formed by the second semiconductor layer (16) and a corresponding bottom structure (442) formed by the first semiconductor layer (14); and when the MEMS shielding member (1) is in the at least one operating state, the top structure of each shielding structure may partially overlap with the bottom structure of the adjacent shielding structure.

[0191] The top structure (440) of each shielding structure (433) may include a protrusion (481”) that protrudes laterally relative to the corresponding bottom structure (442) and leaves an exposed portion (448”) of the corresponding bottom structure (442); and when the MEMS shielding member (1) is in the at least one operating state, the protrusion of the top structure of each shielding structure may partially overlap with the exposed portion of the bottom structure of the adjacent shielding structure.

[0192] Each deformable structure (29, 59, 69, 85) may include a cantilever structure (29) fixed to a support structure (28, 71, 87); and a deformable coupling structure (59) whose ends are fixed to the cantilever structure and the corresponding shielding structure (33; 35; 333; 335; 433) and yield in a direction parallel to the axis (Z) perpendicular to the substrate (2) and in a direction parallel to the corresponding structural direction (R; R') (which is perpendicular to the axis (Z)); and a constraint structure (69, 87). 5) which mechanically couples the shielding structure to the support structure, is rigid along the axis (Z), and yields in a plane (XY) perpendicular to the axis (Z); and each actuator (36) may be piezoelectric, may be coupled to the corresponding cantilever structure (29), and may be electrically controllable to cause the corresponding cantilever structure (29) to translate along the axis (Z) and the corresponding deformable coupling structure (59) to deform accordingly, the corresponding deformation dragging the corresponding shielding structure in a direction parallel to the direction (R; R') of the corresponding structure.

[0193] Each deformable coupling structure (59) may include at least one elongated elastic structure (L1) extending in a lateral direction (TR) in a stationary state, the lateral direction being perpendicular to the axis (Z) and the corresponding structural direction (R; R') and having a first principal axis of inertia (I1) and a second principal axis of inertia (I2) in a plane (ZR) parallel to the axis (Z) and the corresponding structural direction (R; R'), each principal axis of inertia being lateral relative to the axis (Z) and the corresponding structural direction (R; R'), such that movement of the end of each deformable coupling structure (59) fixed to the corresponding cantilever structure (29) along the axis (Z) can cause corresponding movement of the end of the deformable coupling structure (59) fixed to the corresponding shielding structure (33; 35; 333; 335; 433) along the corresponding structural direction (R; R').

[0194] The actuator (96) may be electrostatic and each may include at least one corresponding stator region (ST1), which is fixed relative to the support structure (28; 169; 171) and formed by portions of the first and second semiconductor layers (1416); and at least one corresponding rotor region (100), which is formed by a corresponding portion of at least one of the first and second semiconductor layers and fixed relative to the corresponding shielding structure (33). The actuator is electrically controllable to translate the rotor region and the corresponding shielding structure in a direction parallel to the direction (R) of the corresponding structure. For each shielding structure, the MEMS shielding may also include a corresponding constraint structure (169) that mechanically couples the shielding structure to the support structure, is rigid in a direction parallel to an axis (Z) perpendicular to the substrate (2), and yields in a plane (XY) perpendicular to the axis (Z).

[0195] The first and second semiconductor layers (14, 16) can be made of polycrystalline silicon.

[0196] The process for manufacturing the MEMS shielding element (1) can be summarized as follows: forming a first semiconductor layer (14) on top of a semiconductor material substrate (2); forming a second semiconductor layer (16) on top of the first semiconductor layer (14), the second semiconductor layer (16) together with the first semiconductor layer (14) forming a support structure (28, 71, 87; 28, 171) fixed to the substrate (2); forming a plurality of deformable structures (29, 59, 69, 85; 169), each deformable structure being formed by a corresponding portion of at least one of the first and second semiconductor layers; forming a main aperture (9) through the substrate; forming a plurality of actuators (36; 96); and so on. And forming a plurality of shielding structures (33; 35; 333; 335; 433), each shielding structure being formed by a corresponding portion of at least one of the first and second semiconductor layers, the shielding structures being arranged at an angle around the lower main aperture to form a shield of the main aperture, each shielding structure being further mechanically coupled to a support structure via a corresponding deformable structure; and wherein each actuator is electrically controllable to cause the corresponding shielding structure to translate between a corresponding first position and a corresponding second position, thereby changing the shield of the main aperture; and wherein the first and second positions of the shielding structures are such that, in at least one operating state of the MEMS shielding member (1), adjacent shielding structures at least partially overlap each other.

[0197] The manufacturing process of the MEMS masking element (1) may include: forming a layered region (504, 506) of dielectric material on a substrate (2); selectively removing portions of the layered regions (504, 506) and exposing a portion of the substrate (2); forming an intermediate conductive region (510) on the exposed portion of the substrate (2); forming a first sacrificial dielectric region (515) on the layered regions (504, 506) and the intermediate conductive region (510); selectively removing portions of the first sacrificial dielectric region (515) to expose the intermediate conductive region (510). 510); forming a first semiconductor layer (14) on the first sacrificial dielectric region (515) and the intermediate conductive region (510); forming a second sacrificial dielectric region (525) on the first semiconductor layer (14) such that it covers at least a portion of the intermediate conductive region (510) at a certain distance; forming a second semiconductor layer (16) on the second sacrificial dielectric region (525); and selectively removing portions of the second semiconductor layer (16) to form a top opening (530) that traverses the second semiconductor layer (14) and extends to The shielding structure (33) is partially defined laterally; and forming the main aperture (9) may include selectively removing: portions of the substrate (2) that are in contact with the intermediate conductive region (510); the intermediate conductive region (510); portions of the first semiconductor layer (14) that cover the intermediate conductive region (510) and are covered by corresponding portions of the second sacrificial dielectric region (525), the corresponding portions of the second sacrificial dielectric region (525) being covered by corresponding portions (45) of the shielding structure (33); and the portion of the substrate (2) relative to the intermediate conductive region (510). 0) The portions (504) that are laterally staggered and covered at the top by the corresponding portions of the layered regions (504, 506) relative to the first sacrificial dielectric region (515), the corresponding portions of the first sacrificial dielectric region (515) being covered by the corresponding portions (78) of the shielding structure (35); the process may further include removing the portions of the first and second sacrificial dielectric regions (515, 525) and the layered regions (504, 506) that are laterally staggered relative to the intermediate conductive region (510) to release the shielding structure.

[0198] The manufacturing process may further include patterning a second sacrificial dielectric region (525) to expose portions of the first semiconductor layer (14); and forming a second semiconductor layer (16) such that it contacts the exposed portions of the first semiconductor layer (14).

[0199] The manufacturing process may further include selectively removing portions of the first semiconductor layer (14) prior to forming the second sacrificial dielectric region (525) to form a bottom opening (520) defining at least a portion of the deformable structure (62); and forming the second sacrificial dielectric region (525) may include forming the second sacrificial dielectric region 525 such that it extends within the bottom opening 520 until it contacts the first sacrificial dielectric region (515).

[0200] Forming the layered regions (504, 506) may include forming a first dielectric layer (504) on the substrate (2); and forming a chemically resistant second dielectric layer 506 on the first dielectric layer (504); and selectively removing portions of the layered regions (504, 506) may include selectively removing portions of the second dielectric layer (506) to expose a portion of the first dielectric layer (504); and then removing portions of the exposed portions of the first dielectric layer (504) to expose said portions of the substrate (2); and forming a first sacrificial dielectric region (515) may include forming a first dielectric layer (504, 506, ...6, 504, 506, 506, 506, 504, 506, 506, 506, 506, 506, 506, 506, 506, 506, 506, 506, 506, 506, 506, 506, 506, 506, 50 A first sacrificial dielectric region (516) is formed on the exposed portion of the layered regions (504, 506) that are laterally intersected with the intermediate conductive region (510); and the portion (504) on which the layered regions (504, 506) are laterally intersected with the intermediate conductive region (510) may include the exposed portion of the first dielectric layer (504) that is laterally intersected with the intermediate conductive region (510); and removing the first and second sacrificial dielectric regions (515, 525) and the portion on which the layered regions (504, 506) are laterally intersected with the intermediate conductive region (510) may include performing etching using the chemical reagent.

[0201] The manufacturing process may include forming conductive anchor regions (8) laterally intersecting with the intermediate conductive region (510) on the layered regions (504, 506); and the step of forming a first sacrificial dielectric region (515) may include forming a first sacrificial dielectric region (516) on the conductive anchor regions (8); the process may further include removing additional portions of the first sacrificial dielectric region (515) to expose the conductive anchor regions (8); and forming a first semiconductor layer (14) may include forming a first semiconductor layer (14) on the conductive anchor regions (8).

[0202] The various embodiments described above can be combined to provide further embodiments. Aspects of the embodiments can be modified as needed to incorporate concepts from various patents, applications, and publications to provide further embodiments.

[0203] Based on the detailed description above, these and other changes can be made to the embodiments. Generally, the terminology used in the appended claims should not be construed as limiting the claims to the specific embodiments disclosed in the specification and claims, but should be interpreted to include all possible embodiments and the full scope of equivalents that are entitled to by those claims. Therefore, the claims are not limited by this disclosure.

Claims

1. A MEMS shielding device, comprising: Substrate; The main aperture passes through the substrate; A first semiconductor layer is disposed on the substrate; A second semiconductor layer is disposed on the first semiconductor layer; A support structure is fixed to the substrate by the second semiconductor layer; Multiple deformable structures, each deformable structure being part of at least one of the first semiconductor layer and the second semiconductor layer; Multiple actuators; as well as Multiple shielding structures, each including a portion of at least one of the first semiconductor layer and the second semiconductor layer, the shielding structures surrounding the main aperture, each shielding structure being mechanically coupled to the support structure via a corresponding deformable structure; The paired adjacent shielding structures are configured to at least partially overlap each other in at least one operating state; as well as Each actuator is electrically controllable to cause the corresponding shielding structure to translate between a corresponding first position and a corresponding second position.

2. The MEMS shielding device according to claim 1, wherein the translation of the shielding structure alters the shielding of the main aperture; the plurality of shielding structures include a plurality of first shielding structures and a plurality of second shielding structures arranged at an angle, each first shielding structure including a corresponding top structure of the second semiconductor layer, each second shielding structure including a corresponding bottom structure of the first semiconductor layer; and wherein when the MEMS shielding device is in the at least one operating state, the top structure of each first shielding structure partially overlaps with the bottom structure of the adjacent second shielding structure.

3. The MEMS shielding member of claim 2, wherein each first shielding structure further comprises a corresponding bottom structure formed of the first semiconductor layer, and the corresponding top structure includes at least one protruding portion that projects laterally relative to the corresponding bottom structure; and Each of the second shielding structures includes a corresponding top structure, which is formed by the second semiconductor layer and exposes the exposed portion of the corresponding bottom structure; and When the MEMS shielding element is in the at least one operating state, the protruding portion of the top structure of each first shielding structure at least partially covers the exposed portion of the bottom structure of the adjacent second shielding structure.

4. The MEMS shielding member according to claim 3, wherein when the MEMS shielding member is in the at least one operating state, the protruding portion of the top structure of the first shielding structure and the exposed portion of the bottom structure of the second shielding structure at least partially cover the main aperture.

5. The MEMS shielding member of claim 3, wherein the top structure of each first shielding structure includes a top auxiliary portion fixed relative to a corresponding lower bottom structure and a top main portion extending cantilevered relative to the top auxiliary portion and forming the protrusion; and wherein the bottom structure of each second shielding structure includes a bottom main portion fixed relative to the corresponding covered top structure and forming the exposed portion of the bottom structure.

6. The MEMS shielding member of claim 5, wherein the top main portion and the bottom main portion extend parallel to the corresponding directions; and wherein each actuator is electrically controllable to translate the corresponding first shielding structure or the corresponding second shielding structure parallel to the corresponding direction.

7. The MEMS shielding member according to claim 6, wherein the direction is a radial direction.

8. The MEMS shielding element according to claim 6, wherein the direction is coplanar with and equidistant from the axis of symmetry of the main aperture.

9. The MEMS shielding device of claim 1, wherein each of the shielding structures comprises a corresponding top structure formed by the second semiconductor layer and a corresponding bottom structure formed by the first semiconductor layer; and wherein when the MEMS shielding device is in the at least one operating state, the top structure of each shielding structure partially overlaps with the bottom structure of the adjacent shielding structure.

10. The MEMS shielding member of claim 9, wherein the top structure of each shielding structure includes a protrusion that protrudes laterally relative to the corresponding bottom structure and exposes a portion of the corresponding bottom structure; and wherein when the MEMS shielding member is in the at least one operating state, the protrusion of the top structure of each shielding structure partially overlaps with the exposed portion of the bottom structure of the adjacent shielding structure.

11. The MEMS shielding element of claim 1, wherein each deformable structure comprises: Cantilever structure; as well as A deformable coupling structure, the ends of which are fixed to the cantilever structure and the corresponding shielding structure, and the ends of the deformable coupling structure yield in a direction parallel to an axis perpendicular to the substrate and in a direction parallel to the direction of the corresponding structure, the yielding direction being perpendicular to the axis. as well as A constraint structure, which is coupled to the shielding structure, is rigid along the axis and yields in a plane perpendicular to the axis; Furthermore, each actuator is piezoelectric, coupled to a corresponding cantilever structure, and electrically controllable to cause translation along the axis of the corresponding cantilever structure and subsequent deformation of the corresponding deformable coupling structure, the deformation dragging the corresponding shielding structure in a direction parallel to the direction of the corresponding structure.

12. The MEMS shielding element of claim 11, wherein each deformable coupling structure comprises at least one elongated elastic structure, the elongated elastic structure extending in a transverse direction perpendicular to the axis and the corresponding structural direction in a stationary state and having a first principal axis of inertia and a second principal axis of inertia in a plane parallel to the axis and the corresponding structural direction, each principal axis of inertia being transverse relative to the axis and the corresponding structural direction, such that movement of the end of each deformable coupling structure fixed to the corresponding cantilever structure along the axis causes a corresponding movement of the end of the deformable coupling structure fixed to the corresponding shielding structure along the corresponding structural direction.

13. The MEMS shielding device of claim 1, wherein the actuator is electrostatic, and each actuator comprises: At least one corresponding stator region includes a portion of the first semiconductor layer and a portion of the second semiconductor layer; as well as At least one corresponding rotor region is formed by a corresponding portion of at least one of the first semiconductor layer and the second semiconductor layer and is fixed relative to the corresponding shielding structure. The actuator is electrically controllable to translate the rotor region and the corresponding shielding structure in a direction parallel to the direction of the corresponding structure. For each shielding structure, the MEMS shielding element also includes a corresponding constraint structure coupled to the shielding structure, the constraint structure being rigid in a direction parallel to an axis perpendicular to the substrate and yielding in a plane perpendicular to the axis.

14. A process for manufacturing a MEMS shielding element, comprising: A first semiconductor layer is formed on the substrate; A support structure is formed on the first semiconductor layer and fixed to the substrate by a second semiconductor layer; Multiple deformable structures are formed through corresponding portions of at least one of the first and second semiconductor layers; Forming a main aperture through the substrate; Multiple actuators are formed; as well as Multiple shielding structures are formed through corresponding portions of at least one of the first and second semiconductor layers. The shielding structures are arranged at an angle around the main aperture of the lower layer to form a shield for the main aperture. Each shielding structure is also mechanically coupled to the support structure via a corresponding deformable structure. Furthermore, each actuator is electrically controllable to cause a translation of the corresponding shielding structure between a corresponding first position and a corresponding second position, thereby changing the shielding of the main aperture; and The first and second positions of the shielding structure are such that, in at least one operating state of the MEMS shielding member, adjacent shielding structures at least partially overlap each other.

15. The manufacturing process of the MEMS shielding component according to claim 14, comprising: A layered region of dielectric material is formed on the substrate; Selectively remove portions of the layered region and expose portions of the substrate; An intermediate conductive region is formed on the exposed portion of the substrate; A first sacrificial dielectric region is formed on the layered region and the intermediate conductive region; Selectively remove a portion of the first sacrificial dielectric region to expose the intermediate conductive region; The first semiconductor layer is formed on the first sacrificial dielectric region and the intermediate conductive region; A second sacrificial dielectric region is formed on the first semiconductor layer, such that the second sacrificial dielectric region covers at least a portion of the intermediate conductive region at a certain distance; The second semiconductor layer is formed on the second sacrificial dielectric region; as well as A portion of the second semiconductor layer is selectively removed to form a top opening that extends across the second semiconductor layer and at least partially laterally defines the shielding structure; Furthermore, forming the main aperture includes selectively removing: the portion of the substrate in contact with the intermediate conductive region; the intermediate conductive region; The first semiconductor layer covers the intermediate conductive region and is covered by the corresponding portion of the second sacrificial dielectric region, and the corresponding portion of the second sacrificial dielectric region is covered by the corresponding portion of the shielding structure; And the portion of the substrate that is laterally intersected with respect to the intermediate conductive region and defined at the top by the portions of the layered regions that are laterally intersected with respect to the intermediate conductive region, the intermediate conductive region being covered by the corresponding portion of the first sacrificial dielectric region, the corresponding portion of the first sacrificial dielectric region being covered by the corresponding portion of the shielding structure. The process further includes removing the portions of the first sacrificial dielectric region and the second sacrificial dielectric region, as well as the layered regions that are laterally intersected relative to the intermediate conductive region, to release the shielding structure.

Images